Johannes Strasser¹, Jörg Roland², Gert Reiter³, and Rudolf Stollberger^1
1Institute of Medical Engineering, Graz University of Technology, Graz, Austria, ²Siemens Healthcare, Erlangen, Germany, ³Siemens Healthcare, Graz, Austria

Since liver MRE at 3 T brings along certain challenges due to the high field strength, the aim of this study was to investigate and optimize several acquisition parameters to improve applicability of liver MRE at 3 T. The herewith achieved optimization allowed an increase in image quality and an enhancement of confidence areas in the elastogram accompanied by recognizable shear wave illustration within the liver, and enabled an assessment of liver stiffness values of healthy volunteers within short breath-hold times. Further research is ongoing to establish and simplify liver MRE at 3 T in routine medical liver exams.

Sabrina Doblas¹, Helena S. Leitao^1,2, Philippe Garteiser¹, Gaspard d'Assignies^1,3, Feryel Mouri⁴, Valérie Vilgrain^1,3, Ralph Sinkus¹, Carlos F.G.C. Geraldes², and Bernard E. Van Beers^1,3
1U773-CRB3, INSERM, Paris, France, ²Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal, ³Radiology Department, Beaujon University Hospital, Clichy, France, ⁴Hepatology Department, Beaujon University Hospital, Clichy, France

Confounding factors such as steatosis and inflammation can bias the evaluation of hepatic fibrosis by MR elastography or DWI, 2 techniques proposed as non-invasive approaches to the evaluation of chronic liver diseases. Multivariate analysis of MR elastography and DWI data obtained from a cohort of 58 hepatitis patients showed that viscoelastic parameters preferentially responded to fibrosis, whereas the diffusion coefficient was mostly affected by steatosis.

Sebastian Hirsch¹, Thomas J. Kroencke¹, Jing Guo², Rolf Reiter¹, Sebastian Papazoglou¹, Patrick Asbach¹, Juergen Braun³, and Ingolf Sack^1
1Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Berlin, Germany, ²Department of Radiology, Charite - University Medicine Berlin, Berlin, Berlin, Germany, ³Institute of Medical Informatics, Charite - University Medicine Berlin, Berlin, Berlin, Germany

3D vector field MRE was performed in 13 patients with hepatic portal hypertension before and after interventional TIPPS placement in order to assess the sensitivity of volumetric strain and shear strain to hepatic pressure. The method was validated in an excised sheep liver at artificial hepatic pressure levels. In both studies, volumetric strain was found to decrease with increasing pressure, whereas shear strain appears to be invariant w.r.t pressure changes. In patients, the averaged increase of volumetric strain due to TIPS was 2113, P=1.38∙10-5. Furthermore, we found a strong correlation between the hepatic pressure decrease and volumetric strain (R^2=0.776).

Hadrien A. Dyvorne¹, Guido H. Jajamovich¹, Richard Leroy Ehman², Ersin Bayram³, Bachir Taouli¹, and Richard Leroy Ehman^2
1Mount Sinai School of Medicine, New York, NY, United States, ²Department of Radiology, Mayo Clinic, Rochester, MN, United States, ³GE Healthcare, Waukesha, WI, United States

Two techniques for measuring liver and splenic stiffness using MR elastography were compared. The first uses a single acoustic driver located on the organ of interest, and performs two different acquisitions (one for each organ). The second technique aims to calculate both liver and splenic stiffness from a single acquisition, by using two drivers exciting both organs in parallel. Liver and splenic stiffness values were compared in 29 subjects and were found to be in good agreement between the two techniques. A comparison between cirrhotic and non cirrhotic populations revealed significantly higher stiffness values in liver and spleen in cirrhotic subjects.

Philippe Garteiser¹, Gaspard D'Assignies^1,2, Helena S. Leitao^1,3, Ramin S. Sahebjavaher⁴, Simon Auguste Lambert¹, Feryel Mouri⁵, Valérie Vilgrain^1,2, Bernard E. Van Beers^1,2, and Ralph Sinkus^1
1U773-CRB3, INSERM, Universite Sorbonne Paris-Cite, Paris, 75018, France, ²Service de Radiologie, AP-HP Hopital Beaujon, Clichy, 92110, France, ³Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, 3004-517, Portugal, ⁴University of British Columbia, Vancouver, BC, Canada, ⁵Service d'hepatologie, AP-HP Hopital Beaujon, Clichy, 92110, France

Accurate noninvasive methods for the determination of chronic liver inflammation are still lacking in clinical practice, despite the high relevance to patient care. In the present work, multi-frequency MR elastography (28, 56 and 84Hz) was carried out on 26 patients with viral hepatitis. Results were confronted to the inflammation grade obtained from histology of tissue biopsies. Statistical analysis revealed a strong dependence of the dispersion property of the wavelength to inflammation. This trend was visible independently from the variations caused by fibrosis. Hence, the dispersion of the mechanical wavelength obtained by MRE may represent a novel marker of hepatic inflammation.

Sohae Chung¹ and Leon Axel^1
1Radiology Department, Center for Biomedical Imaging, NYU Langone Medical Center, New York, NY, United States

Magnetization-tagged MRI was used to measure the cardiac-induced motion and deformation in the liver for assessing liver stiffness. In this study, we extended the previously used simple elastography estimation of liver stiffness, which have primarily considered the elasticity alone, to include viscoelastic properties, by looking at the time behavior of the cardiac-induced motion. A single degree-of-freedom (SDOF) viscoelastic model was applied in healthy subjects and patients with cirrhosis. The results showed statistically significant differences in the "stiffness" and the "damping" between healthy and cirrhosis livers, and it may provide an additional novel means for tissue characterization.

Bin Yang¹, Li Wang¹, Chunmei Xia², Lixia Yang³, Zhongwei Qiao¹, and Ed X. Wu^4
1Department of Radiology, Children Hospital of Fudan University, Shanghai, China, ²Department of Physiology and Pathophysiology, Fudan University, Shanghai, China, ³Department of Radiology, Xuhui Center Hospital, Shanghai, China, ⁴Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China

This study aims to investigate the alteration of D, D* and perfusion faction (f) in the rat liver fibrosis with biliary duct ligation by using IVIM DW-MRI. We observed a decreasing trend of D, f and ADC of the livers from D0 to D3, D7. And the differences in D, f and ADC approached statistical significance on D7 compared to D0. There was no difference in D* of the livers from D0 to D3, D7. The reduction of true diffusion and perfusion faction would be attributed to alteration of hepatic microcirculation, portal inflammation at the early stage of liver fibrosis.

Pu-Xuan Lu¹, Hua Huang¹, Jing Yuan², Feng Zhao², and Yi-Xiang Wang^2
1Department of Radiology, the Shenzhen Third People's Hospital, Shenzhen, Guangdong, China, ²Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong

11 healthy volunteers and 11 patients with liver fibrosis received IVIM DWI at 1.5-T with a single-shot EPI, with 10 b values ranging from 10 to 800 sec/mm2. Avoiding artifacts and blood vessels, an ROI was placed over the whole liver. Parameters of true diffusion coefficient D, pseudo diffusion coefficient that reflects capillary perfusion D*, and perfusion fraction f were computed by fitting the averaged intensities in the ROI with b. The D value in patients was significantly lower than that in healthy subjects (p=0.013). f value was also lower in the patients, though statistical significance was not reached (p=0.066).

Hadrien A. Dyvorne¹, Guido H. Jajamovich¹, M. Isabel Fiel², Douglas Dieterich², Valerie Martel-Laferriere², Scott Friedman², Claudia Donnerhack¹, Richard Leroy Ehman³, and Bachir Taouli^1
1Mount Sinai School of Medicine, New York, NY, United States, ²Department of Medicine/Liver Disease, Mount Sinai School of Medicine, New York, NY, United States, ³Department of Radiology, Mayo Clinic, Rochester, MN, United States

This prospective study compares different techniques: IVIM DWI, MR elastography and ultrasound elastography, for staging of liver fibrosis in HCV patients. When comparing MRI and ultrasound findings with histologic findings, liver stiffness (measured with MR elastography and ultrasound) showed better performances than IVIM DWI for the detection of liver fibrosis.

Gregory R. Lee^1,2, Yong Chen^3,4, Nicole Seiberlich⁵, Mark A. Griswold^3,4, and Vikas Gulani^4,6
1Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, ²Radiology, University of Cincinnati, Cincinnati, OH, United States,³Radiology, Case Western Reserve University, Cleveland, OH, United States, ⁴Radiology, University Hospitals of Cleveland, Cleveland, OH, United States,⁵Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ⁶Radiology, University Hospitals Case Medical Center, Cleveland, OH, United States

Dynamic contrast enhanced (DCE) liver exams are typically performed using 15-20 second breath-holds at a few timepoints surrounding contrast arrival. In the present work, a multi-echo 3D radial acquisitions with nearly isotropic sample spacing regardless of timescale was employed to enable reconstruction of DCE images at multiple timescales which can be chosen retrospectively. At longer timescales, higher signal to noise ratio is available for better single volume radiologist interpretation, while at shorter timescales the dynamic contrast uptake curves can be fit to a quantitative perfusion model.

Hersh Chandarana¹, Kai Tobias Block¹, Henry Rusinek¹, Matthew B. Greenberg¹, Li Feng², Daniel K. Sodickson¹, and Ricardo Otazo^1
1Radiology; Center for Biomedical Imaging, NYU Langone Medical Center, New York, NY, United States, ²Radiology; Center for Biomedical Imaging, New York University Langone Medical Center, New York, NY, United States

Studies have shown the utility of perfusion weighted MR imaging in diagnosis of liver fibrosis and assessment of portal hypertension. Here we performed free-breathing high spatial and temporal resolution liver imaging with compressed sensing technique called GRASP. GRASP data was reconstructed with temporal resolution of 3 seconds and processed with dual-input single compartment model to generate perfusion metrics, which were significantly different in cirrhotics compared to healthy subjects. Advantages over Cartesian scheme are higher resolution, motion robustness eliminating need for labor-intensive registration, and generating dynamic perfusion data from routine clinical exam, hence eliminating need for additional contrast dose or acquisition time.

Manojkumar Saranathan¹, Dan W. Rettmann², Brian Andrew Hargreaves¹, Andreas Loening¹, Anja C.S Brau³, KyungHyun Sung¹, and Shreyas S. Vasanawala^1
1Dept. of Radiology, Stanford University, Stanford, CA, United States, ²Applied Science Laboratory, GE Healthcare, Rochester, MN, United States, ³GE Healthcare, Menlo Park, CA, United States

Dynamic contrast-enhanced abdominal imaging is commonly performed in a series of breathholds following injection of Gadolinium contrast. In many patients, breathholding is not possible or unreliable, leading to ghosting and blurring. Free-breathing radial VIBE or navigator gating can address this problem, but with a temporal resolution penalty. Here, we used DISCO a navigator-gated 3D SPGR sequence with a combination of parallel imaging, viewsharing and pseudo-random variable density k-space sampling. This enables free-breathing dynamic contrast enhanced abdominal imaging at high temporal and spatial resolution.

Thomas A. Hope¹, Manojkumar Saranathan¹, Iva Petkovska¹, Brian Andrew Hargreaves¹, Robert J. Herfkens¹, and Shreyas S. Vasanawala^1
1Department of Radiology, Stanford University, Stanford, CA, United States

To determine whether a method that improves temporal resolution via a combination of parallel imaging and temporal view sharing improves the capture of gadoxetate arterial phase after the administration of gadoxetate disodium. 37 patients were imaged with a conventional technique and 48 patients were imaged with the accelerated technique. A multiphase acquisition included the arterial phase more frequently than the conventional acquisition, with 17% of patients imaged with conventional acquisition missed the arterial phase compared to 2% with the multiphase acquisition. Additionally, there was increased relative intensity of the hepatic arteries and improved lesion enhancement with respect to adjacent parenchyma.

Matthieu Lagadec¹, Sabrina Doblas¹, Celine Giraudeau¹, Jean-Luc Daire¹, Simon Auguste Lambert¹, Magali Fasseu¹, Valerie Paradis¹, Richard Moreau¹, and Bernard E. Van Beers^1
1INSERM Centre de recherche Biomédicale Bichat Beaujon, CRB3 U773, Université Paris Diderot, Sorbonne Paris Cité, Paris, Ile de France, France

The hepatic function is important to assess in liver cirrhosis because it has both prognostic and therapeutic implications. This study aims at evaluating the relationship between Dynamic hepatospecific contrast enhanced-MRI with Gd-EOB-DTPA with hepatocyte transporter expression. MRI data was analyzed quantitatively through deconvolution analysis to determine the hepatic extraction fraction and the input relative blood flow. Our results show that the hepatic functional parameters determined at Gd-EOB-DTPA enhanced MRI correlate with the changes of hepatocyte transporters of the OATP1-MRP and NTCP systems in liver cirrhosis and suggest that the extraction fraction of Gd-EOB-DTPA is a marker of the decreased hepatocyte uptake function in liver cirrhosis

Lauren M.B. Burke¹, Xiaodong Zhong², Ghaneh Fananapazir¹, Brian M. Dale³, Dominik Nickel⁴, Stephan A.R. Kannengiesser⁴, and Mustafa R. Bashir^1
1Radiology, Duke University Medical Center, Durham, NC, United States, ²MR R&D Collaborations Siemens Healthcare, Atlanta, GA, United States, ³MR R&D Collaborations, Siemens Healthcare, Morrisville, NC, United States, ⁴Healthcare Sector Imaging & Therapy Division, Siemens AG, Erlangen, Germany, Germany

Quantification of lipid content during contrast-enhanced MR abdominal examinations would be clinically helpful in the evaluation of hepatic metabolism, particularly if this could be accurately obtained following IV contrast administration without adding scan time to each individual patient. We investigated a 3D MRI technique with a multi-step adaptive fitting method for image reconstruction to measure liver proton density fat fraction. We compared this method on pre-contrast and post-contrast imaging with single voxel spectroscopy, and demonstrated a high correlation between the proton density fat fraction measured after contrast administration using the MRI method and both pre-contrast measurements.

Liana Rocha¹, Caroline Amoedo¹, Fernanda Magão¹, Marcio Reis¹, Ralph Strecker², Xiadong Zhong³, Stephan A.R. Kannengiesser⁴, and Ronaldo Baroni^1
1Imaging Department, Hospital Israelita Albert Einstein, São Paulo, São Paulo, Brazil, ²Healthcare MR, Siemens Ltda, São Paulo, São Paulo, Brazil, ³MR R&D Collaborations, Siemens Healthcare, Atlanta, Geogia, United States, ⁴Healthcare MR, Siemens, Erlangen, Bavaria, Germany

Magnetic resonance imaging (MRI) has been recognized as a non-invasive method for detection and quantification of fat and iron deposition in the liver. Recently, a two-point automated dual-ratio Dixon discrimination technique with automatic liver segmentation, dubbed screening Dixon (SD), has emerged as a potential method for screening and discrimination of fat and iron signals. The purpose of this study was to evaluate the accuracy of the SD sequence with automatic estimation of fat/ iron contents in a population of chronic liver disease (presence of siderotic lesions and steatosis) and compare them with the results of our routine quantitative sequences as the reference standards: GRE multi-echo for Iron deposition and 3-echo GRE Dixon for fat. 70 abdominal MRI performed at 1,5T were compared. Considering only the presence (altered) or absence (normal) of disease, SD demonstrates 100%, 86.96% and 91.43% for sensitivity, specificity and accuracy, resp. When we considered only presence or absence of FD, SD was more specific (90.38%) than sensitive (50%), with accuracy of 80%. When we considered only the presence or absence of ID, SD was 100% sensitive, with specificity of 82.76% and accuracy of 85.71%. Although the type of deposition is not perfectly discriminated, SD is an accurate method for detecting presence or absence of fat/iron deposition in the liver, being adequate as a screening technique in general MRI abdominal studies.

Marek Chmelík¹, Ladislav Valkovic^1,2, Peter Wolf³, Wolfgang Bogner^1,4, Martin Gajdosik¹, Stephan Gruber¹, Michael Krebs³, Siegfried Trattnig¹, and Martin Krssák^1,3
1MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria, ²Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, ³Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria, ⁴Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General, Boston, MA, United States

³¹P MR hepatic signal at 2.06ppm was previously assigned to phosphoenolpyruvate (PEP) but contribution to this signal from phosphatidylcholine (PtdC part of lecithin) which is dominant metabolite in bile should also be considered. The purpose of this study was to assess possible contribution of PtdC to this signal by in-vitro measurements of test object solutions (PEP and PtdC) and by ³¹P 3D MRSI in-vivo measurements including signals from hepatic parenchyma and gall bladder. Based on both phantom and in vivo data we can suggest that ³¹P MR hepatic signal at 2.06ppm may be rather bile phosphatydilcholine (lecithin) than phosphoenolpyruvate.

Hadrien A. Dyvorne¹, Ashley Knight-Greenfield¹, Nancy Cooper¹, Cecilia Besa¹, Ricardo Otazo², Daniel K. Sodickson², and Bachir Taouli^1
1Mount Sinai School of Medicine, New York, NY, United States, ²New York University Langone Medical Center, New York, NY, United States

A high resolution, highly accelerated phase contrast (PC) sequence using a joint compressed sensing and parallel imaging approach (k-t SPARSE-SENSE) was used for the detection of hemodynamic changes in non cirrhotic and cirrhotic liver within a single breath-hold. The high spatial resolution provided by the technique allowed for better depiction of the hepatic artery as compared to a conventional parallel imaging PC. When comparing flow parameters of non cirrhotic and cirrhotic subjects, we observed significantly decreased portal vein velocity and increased arterial fraction in cirrhotic subjects.

Feng Zhao¹, Jing Yuan¹, Min Deng¹, and Yi-Xiang Wang^1
1Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong

In our previous liver T1rho MR imaging, the rotary-echo spin-lock pulse was used for T1rho preparation, and NSA was 2. The method described by Dixon et al. [MRM 1996; 36:90-4. MRI 2011; 29:608-19], proposed to reduce sensitivity to B0 field inhomogeneity in T1rho imaging, was implemented in this study. Images with NSA=1 and histogram measurement was also evaluated. The results showed Dixon method did not reduce artifacts for liver T1rho MR imaging. The histogram and manual ROI measurement provided similar liver T1rho value. While reducing the breath¨Cholding duration significantly, NSA=1 did not offer satisfactory SNR.

Tomoyuki Okuaki¹, Yukihisa Takayama², Akihiko Nishie³, Makoto Obara⁴, Tetsuo Ogino⁴, Hiroshi Honda³, and Marc Van Cauteren^1
1Philips Healthcare Asia Pacific, Minato-ku, Tokyo, Japan, ²Department of Molecular Imaging and Diagnosis, Kyushu University, Graduate School of Medical Science, Fukuoka, Fukuoka, Japan, ³Department of clinical Radiology, Kyushu University, Graduate School of Medical Sciences, Fukuoka, Fukuoka, Japan,⁴Philips Electronics Japan, Minato-ku, Tokyo, Japan

An adiabatic locking pulse is applied to obtain homogeneous spin locking and compared with block pulse locking. Visual evaluation was done to assess the homogeneous of the T1rho maps and T1rho values obtained by both methods were measured. The visual evaluation of T1rho maps obtained by adiabatic locking was scored higher (p value<0.05) and T1rho values obtained by adiabatic were significantly different between normal and Child-Pugh BorC(Kruskal-Wallis method, p value<0.05). Adiabatic spin locking method provided homogeneous and artifact free liver T1rho maps at 3T. This is expected to be useful for robust evaluation of liver function using T1rho.

Eleanor F. Cox¹, Antonella Ghezzi², Andrea Bennet², Mina Patel², Andrew Jackson², David Harman², Carolyn Costigan¹, Martin W. James², Stephen D. Ryder², Penelope A. Gowland¹, Guru P. Aithal², I. Neil Guha², and Susan T. Francis^1
1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ²NIHR Biomedical Research Unit in Gastrointestinal and Liver Diseases, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

Here we use the MR longitudinal relaxation parameter to study compensated cirrhosis and compare with two different validated and non-invasive techniques. We find measures of liver longitudinal relaxation time (T₁) are highly correlated with liver stiffness measured using transient elastography for cirrhotic patients and the enhanced liver fibrosis (ELF) test across both healthy volunteers and cirrhotic patients. All three non-invasive tools are able to stratify disease severity in compensated cirrhosis. Importantly, the heterogeneity of T₁ across the whole liver can be seen, which cannot be assessed with either ELF score or stiffness measures.

Hernan Jara¹, Yu Sakai¹, and Stephan Anderson^2
1Boston University Medical Center, Boston, Massachusetts, United States, ²Boston University Medical Center, Boston, MA, United States

Purpose: To monitor hepatic fibrosis progression in murine model via PD and T2, using adaptive iterative qMRI processing algorithms and whole-sample histogram analysis. Methods: Multi-echo CPMG images of murine livers with DDC-induced fibrosis at 11.7T were processed by algorithms which auto-detect the optimal number of echoes used for semi-logarithmic linear regression on a pixel-by-pixel basis. Whole-sample histograms were generated from multislice PD and T2 qMRI volumetric datasets and correlated with fibrosis measures. Results: Histogram PD-, T2-peak values displayed linear inverse correlation with fibrosis progression. Conclusion: In absence of steatosis, PD and T2 calculated by adaptive iterative algorithms are reliable correlates of hepatic fibrosis.

Nikita Garnov¹, Henriette Bertram¹, Gregor Thörmer¹, Thomas Karlas², Tatjana Schütz³, Thomas Kahn¹, and Harald Busse^1
1Diagnostic and Interventional Radiology, Leipzig University Hospital, Leipzig, Germany, ²Internal Medicine, Neurology and Dermatology, Leipzig University Hospital, Leipzig, Germany, ³Visceral, Transplantation, Thoracic and Vascular Surgery, Leipzig University Hospital, Leipzig, Germany

T1 relaxation times of adipose tissue have often been used to correct for T1 effects in the quantification of liver fat content. These values, however, were derived in healthy lean subjects and may therefore vary from those in obese patients. This work determines T1 relaxation times at 1.5 T in subcutaneous and visceral adipose tissue in morbidly obese subjects and patients with NAFLD. The results showed that the T1 values in adipose tissue of both obese and lean NAFLD patients can be significantly shorter than those in healthy controls.

Bahar Mansoori¹, Karin Anna Herrmann¹, Pablo Riera Ros¹, and Raj Mohan Paspulati^1
1Radiology, Case Western Reserve University, Cleveland, Ohio, United States

Ten to 15% of patients with clinical symptoms suggestive of biliary lithiasis have no gallstones and normal findings in morphologic imaging studies. Secretin-enhanced MRCP has proven to improve the assessment of chronic pancreatitis and sphincter of Oddi dysfunction. Secretin, however, has no effect on the gallbladder, a function reserved to CCK. Purpose of this study was to utilize MR imaging to show the effects of Sincalide on the gallbladder and biliary tree, and to establish a MR imaging protocol with appropriate dose and timing for dynamic Sincalide-enhanced MRCP of the gallbladder and biliary system.

Mark L. Schiebler¹, Jitesh Ahuja¹, Christopher J. François², Harald Kramer¹, Scott B. Reeder¹, Thomas M. Grist², Michael Repplinger³, and Scott K. Nagle^1
1Radiology, UW-Madison, Madison, Wisconsin, United States, ²Radiology, University of Wisconsin-Madison, Madison, Wisconsin, United States, ³Medicine, UW-Madison, Madison, Wisconsin, United States

In the acute setting, clinically significant non-thrombotic ancillary findings, that may provide an alternative explanation for a patient’s chest pain, are found on MRA-PE exams with the same relative frequency as CTA-PE, while less significant incidental findings are not identified.

Yannick Crémillieux¹ and Mathieu Lederlin^2
1CRCTB, University of Bordeaux Segalen, Bordeaux, France, ²CRCTB, Université de Bordeaux, Bordeaux, France

In this study, lung tissue density was investigated in healthy subjects (N=12) using three dimensional UTE (Ultra Short Echo Time) MRI. Acquisitions were performed during free breathing (gated at functional residual capacity) and during hold-breath (at residual volume and total lung capacity). Lung-to-muscle signal ratio and signal to noise ratio (SNR) were measured in basal, mid and apical levels. Average SNR in peripheral lung parenchyma ranged between 35 (free breathing) and 7 (total lung capacity). Proton-density weighted MRI protocols allowed measurements of vertical gradients in lung tissue density and variations in tissue density related to the level of lung inflation.

Yoshiharu Ohno^1,2, Shinichiro Seki³, Mizuho Nishio^1,2, Hisanobu Koyama³, Takeshi Yoshikawa^1,2, Sumiaki Matsumoto^1,2, Nobukazu Aoyama⁴, Katsusuke Kyotani⁴, Makoto Obara⁵, Marc van Cauteren⁵, Masaya Takahashi⁶, Hideaki Kawamitsu⁴, Satoru Takahashi⁴, and Kazuro Sugimura^3
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ³Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ⁴Center forRadiology and Radiation Oncology, Kobe University Hospital, Kobe, Hyogo, Japan, ⁵Philips Healthcare, Tokyo, Tokyo, Japan, ⁶Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States

In 2010, pulmonary MR imaging using ultra-short echo times (UTE-MRI) was introduced as a new tool for quantitative measurement of T2* values in the lung. However, one of the technical problems associated with using this technique is thought to be determination of ultra-short TEs (UTEs) appropriate for this purpose. We hypothesized a shorter UTE interval is better for such assessment and classification in smokers. The purpose of this study was thus to assess the influence of UTE intervals, compared with that of quantitatively assessed thin-section CT, on pulmonary UTE-MRI for pulmonary functional loss assessment and clinical stage classification of smokers.

Laura C. Bell¹, Kevin M. Johnson^1,2, Sean B. Fain^1,2, Randi Drees³, and Scott K. Nagle^1,2
1Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, ²Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States, ³Veterinary Medicine, University of Wisconsin - Madison, Madison, Wisconsin, United States

For dynamic contrast-enhanced pulmonary perfusion MRI, spatial resolution is usually compromised for full lung coverage and high temporal resolution making it difficult to detect structural abnormalities (e.g. pulmonary emboli or interstitial lung disease) on the same scan. This work demonstrates a method to simultaneously acquire both perfusion images and co-registered high-resolution structural images using breath-held 3D radial UTE in healthy subjects.

Andrea Bianchi¹, Sandrine Dufort^2,3, François Lux⁴, Jean-Luc Coll², Olivier Tillement⁴, and Yannick Crémillieux^1
1Cardio-Thoracic Center of Bordeaux, University of Bordeaux Segalen, Bordeaux, France, France, ²University Joseph Fourier, Saint-Martin-d'Hères, France, France, ³Nano-H, Saint Quentin - Fallavier, France, France, ⁴Laboratoire de Physico-Chimie des Matériaux Luminescents, University Claude Bernard, Villeurbanne, France, France

Intratracheal administration of contrast agents based on nanostructures is a promising approach in the diagnosis of lung diseases. The characterization of contrast media pharmacokinetics (PK) and elimination pathways is fundamental to understand the potential of a given contrast agent and its toxicity, main limiting factor in the translatability of preclinical to clinical studies. We present here an in vivo MRI study of the PK and biodistribution of Gd-based intratracheally-administrated multimodal Ultra-Small Rigid Platforms (USRPs) and of a commercially available Gd-based contrast agent. The implemented MRI PK models for lungs and kidneys were validated against optical imaging.

Karl-Heinz Herrmann¹, Martin Krämer¹, Martin Stenzel², Hans-Joachim Mentzel², and Jürgen R. Reichenbach^1
1Medical Physics Group, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany,²Pediatric Radiology, Institute of Diagnostic and Interventional Radiology I, Jena University Hospital - Friedrich Schiller University Jena, Jena, Germany

Three young patients suffering from different lung diseases are examined using a high resolution, spoiled gradient echo, 3D radial center-out UTE sequence with free breathing acquisition. The resulting images provide sufficient resolution and SNR to confidently detect small lesions or diffuse ground glass opacities. The echo time of 70µs overcomes the very fast T2* relaxation in the lung while the 3D radial trajectory with oversampling in all directions suppresses all fold-over artifacts and renders the images very robust against cardiac, respiratory and patient motion. UTE is a very promising sequence technique for assessment of pediatric and young adult patients in whom computed tomography should be avoided, as the ionizing radiation issue is of most concern in young patients.

Yoshiharu Ohno^1,2, Shinichiro Seki³, Mizuho Nishio^1,2, Hisanobu Koyama³, Takeshi Yoshikawa^1,2, Sumiaki Matsumoto^1,2, Nobukazu Aoyama⁴, Katsusuke Kyotani⁴, Makoto Obara⁵, Marc van Cauteren⁵, Hideaki Kawamitsu⁴, Satoru Takahashi^3,4, and Kazuro Sugimura^3
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ³Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ⁴Center forRadiology and Radiation Oncology, Kobe University Hospital, Kobe, Hyogo, Japan, ⁵Philips Healthcare, Tokyo, Tokyo, Japan

Oxygen (O2) -enhanced MRI as well as hyperpolarized noble gas MR imaging have been proposed as useful procedures for evaluation of morphological changes or regional pulmonary functional changes. However, the literature shows no publications dealing with prospective and direct comparison of the capability of quantitatively assessed CT and of O2-enhanced MRI for pulmonary functional loss assessment and clinical stage classification in asthmatics. The purpose of the study reported here was to prospectively and directly compare the efficacy of O2-enhanced MRI and quantitative CT for functional loss assessment and clinical stage classification in asthmatics.

Lan Lu¹, Elliott C. Dasenbrook², David Weaver², Peter M. Jakob³, Mitchell L. Drumm², Michael W. Konstan², and Chris A. Flask^1
1Department of Radiology, Case Western Reserve University, Cleveland, OH, United States, ²Department of Pediatrics, Case Western Reserve University, Cleveland, OH, United States, ³Department of Physics, University of Wurzburg, Wurzburg, Germany

We have developed a method to normalize lung T1 relaxation time assessments as an biomarker for early-stage lung disease in cystic fibrosis (CF) patients. The T1 relaxation times were normalized by the mean T1 values in the central lung regions to limit the effects of anatomic variation. Normalized T1 assessments were obtained for six CF patients and five healthy controls. The normalized T1 relaxation time assessments showed reduced variation in comparison to conventional T1 relaxation times and differentiated early-stage CF patients from healthy controls while gold-standard pulmonary function tests did not suggesting greater sensitivity of this new MRI method.

Shigeaki Umeoka¹, Yukinori Matsuo², Tomohisa Okada¹, Aki Kido¹, Yusuke Iizuka², Masahiro Hiraoka², and Kaori Togashi^1
1Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan, ²Department of Radiation Oncology and Image-applied Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan

Apparent diffusion coefficient (ADC) value of lung cancer calculated from diffusion-weighted imaging (DWI) has a potential for predicting early tumor response or predicting prognosis for patients who underwent radiotherapy. However, it has not been fully discussed appropriate timing for ADC to assess tumor response. Thus, we prospectively evaluated the optimal timing of DWI in patients with non-small lung cancer who underwent Stereotactic Body Radiotherapy (SBRT). Our study indicated that DWI at six months after SBRT seemed the best timing for assessing tumor response compared with DWI at pre-, three months after, nine months after, and twelve months after SBRT.

Christine U. Lee¹, Peter D. Kollasch¹, Darin White¹, Schmitz J. John¹, James F. Glockner¹, and Anne-Marie G. Sykes^1
1Radiology, Mayo Clinic, Rochester, MN, United States

We present a prospective preliminary study to correlate apparent diffusion coefficient (ADC) values of lung nodules and masses with surgical histopathology.

Hersh Chandarana¹, Laura Heacock¹, Rajan Rakheja¹, Linda DeMello¹, John Bonavita¹, Kai Tobias Block¹, Christian Geppert², and Kent Friedman^1
1Radiology, NYU Langone Medical Center, New York, NY, United States, ²Siemens Medical Systems, New York, NY, United States

Recently introduced integrated whole-body PET/MR systems may play an important role in oncologic evaluation. However, there are concerns regarding ability of MRI in detecting pulmonary nodules. 32 consecutive patients undergoing clinically indicated 18F-FDG-PET/CT immediately followed by PET/MR (Siemens Biograph mMR) were studied. MR imaging was performed simultaneously with PET acquisition using a free-breathing radial 3D fat-suppressed T1-weighted gradient echo sequence (Radial VIBE-RV). RV detected all FDG avid nodules greater than 0.7 cm in size but had lower sensitivity for small nodules and non-FDG avid nodules. This has important implications for oncologic imaging with PET/MR.

Francesca Pennati¹, James D. Quirk², Yulin V. Chang³, Dmitriy A. Yablonskiy², Richard A. Pierce⁴, Mario Castro⁴, Andrea Aliverti¹, and Jason C. Woods^2
1Bioingegneria, Politecnico di Milano, Milano, Milano, Italy, ²Radiology, Washington University, St Louis, MO, United States, ³Radiology, Washington University in Saint Louis, St Louis, MO, United States, ⁴Internal Medicine, Washington University, St Louis, MO, United States

Evaluation of regional ventilation is of major importance in investigating lung function in health and disease. In this study, parenchymal signal change between different lung volumes, acquired with VIBE sequences, was proposed to measure regional ventilation. In a range of patients with obstructive pulmonary diseases, proton signal difference was compared with the corresponding 3He ventilation images and with healthy. We demonstrated the feasibility of conventional proton MRI, combined with image registration, to quantify regional ventilation, emerging as a new clinical and research tool to identify structure-function relationships with no need for special equipment and with no ionizing radiation.

Mark E. Wagshul¹, Sanghun Sin², David M. Wootton³, Michael L. Lipton^1,4, Keivan Shifteh⁴, and Raanan Arens^2
1Radiology, Gruss MRRC, Albert Einstein College of Medicine, Bronx, NY, United States, ²Pediatrics, Montefiore Medical Center, Bronx, NY, United States,³Mechnical Engineering, The Cooper Union for the Advancement of Science and Art, New York, NY, United States, ⁴Radiology, Montefiore Medical Center, Bronx, NY, United States

Retrospective, 3D cine imaging using respiratory gating has the ability to demonstrate high resolution, dynamic imaging of the upper airway. This is an important technique for studying airway motion in obstructive sleep apnea syndrome (OSAS), and will ultimately allow accurate modeling of upper airway motion for designing optimal treatments. Cine imaging was used in 24 adolescents being evaluated for polycystic ovary syndrome, a condition with high OSAS prevalence. In two OSA patients with severe obstruction of the upper airway, the technique allowed visualization of asynchronous airway motion, compared to mostly synchronous airway motion in non-OSAS patients.

Ahmed F. Halaweish^1,2, William Michael Foster³, Richard E. Moon⁴, Neil R. MacIntyre³, James R. MacFall¹, and H. Cecil Charles^1,2
1Radiology, Duke University School of Medicine, Durham, NC, United States, ²Duke Image Analysis Laboratory - Radiology, Duke University School of Medicine, Durham, NC, United States, ³Medicine - Pulmonary, Duke University School of Medicine, Durham, NC, United States, ⁴Anesthesiology - GTVU Divison, Duke University School of Medicine, Durham, NC, United States

The renewable nature of the fluorine (¹⁹F) signal in conjunction with fast imaging sequences, presents itself as a non-invasive radiation-free technique to assess pulmonary ventilation at steady-state equilibrium, providing regional assessments of ventilation efficiency and wash-in and wash-out rates. Subjects (n=29) were recruited and imaged on a Siemens TIM Trio 3T MRI scanner utilizing a 3D GRE VIBE sequence, performing several breath-holds interspersed with 3-5 breaths of perfluoropropane (PFP). Analysis of the data demonstrated a clear difference between normal and emphysemic lungs, where the latter demonstrated a weaker ventilation signal throughout the lungs and increased gas-trapping. These results demonstrate the feasibility of multi-breath steady state assessments via ¹⁹F MRI, as a radiation-free alternative to the early CT work performed utilizing xenon gas.

Yoshiharu Ohno^1,2, Mizuho Nishio^1,2, Hisanobu Koyama³, Takeshi Yoshikawa^1,2, Sumiaki Matsumoto^1,2, Nobukazu Aoyama⁴, Katsusuke Kyotani⁴, Saori Satou⁵, Hideaki Kawamitsu⁴, Satoru Takahashi^3,4, and Kazuro Sugimura^3
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ³Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ⁴Center forRadiology and Radiation Oncology, Kobe University Hospital, Kobe, Hyogo, Japan, ⁵Toshiba Medical Systems, Ohtawara, Tochigi, Japan

Recurrence assessment is important for management of postoperative NSCLC patients. We hypothesized that quick and segmented 3D T1-weighted gradient echo sequence (Quick 3D) and a double fat suppression RF pulse (DFS) technique could improve the diagnostic performance of CE-WB-MRI using a 3T MR system as compared with CE-WB-MRI without Quick 3D and DFS, and might be at least as effective as FDG-PET/CT and conventional radiological examinations in this setting. The purpose of this study was thus to compare diagnostic capabilities for assessment of recurrence of CE-WB-MRI with and without Quick 3D and DFS, PET/CT and conventional radiological examinations.

Yoshiharu Ohno^1,2, Mizuho Nishio^1,2, Hisanobu Koyama³, Takeshi Yoshikawa^1,2, Sumiaki Matsumoto^1,2, Nobukazu Aoyama⁴, Katsusuke Kyotani⁴, Saori Satou⁵, Hideaki Kawamitsu⁴, Satoru Takahashi^3,4, and Kazuro Sugimura^3
1Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ³Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ⁴Center forRadiology and Radiation Oncology, Kobe University Hospital, Kobe, Hyogo, Japan, ⁵Toshiba Medical Systems, Ohtawara, Tochigi, Japan

During the past decade, several novel procedures have been introduced as a new version of non-CE-MRA angiography using 2D or 3D fresh blood imaging (FBI) obtained with an ECG-gated 3D half-Fourier fast spin-echo sequence, and 2D or 3D time spatial labeling inversion pulse (time-SLIP) techniques. However, to the best of our knowledge, no direct comparison has been made of assessment of pulmonary vasculature in candidates for thoracic surgery by non-CE-MRA, 4D CE-MRA at 3T, and thin-section CE-MDCT. The purpose of this study was to compare assessment of pulmonary vasculature in NSCLC patients before surgical treatment among three methods.

Peter Komlosi¹, Talissa A. Altes¹, Kun Qing¹, Karen E. Mooney², G. Wilson Miller¹, Jaime F. Mata¹, Eduard E. De Lange¹, William A. Tobias², Gordon D. Cates Jr.², and John P. Mugler, III^1
1Department Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States, ²Department of Physics, University of Virginia, Charlottesville, VA, United States

Because the magnetization of hyperpolarized gases is independent of the static magnetic field strength of the MR scanner, there has been significant interest in the possibility of imaging at magnetic field strengths lower than those most commonly used for clinical MRI. The goal of the present study was to evaluate the field-strength dependence of hyperpolarized helium-3 signal-to-noise ratio, and T2 and T2* values, for MRI of the human lung between 0.4T and 1.5T. We found similar signal-to-noise ratio values at field strengths between 0.4T and 1.5T. T2 and T2* values demonstrated an inverse relationship to field strength, as expected.

Chengbo Wang¹, John P. Mugler, III², Eduard E. De Lange², G Wilson Miller², and Talissa A. Altes^2
1Faculty of Science and Engineering, University of Nottingham Ningbo China, Ningbo, Zhejiang, China, ²Radiology and Medical Imaging, University of Virginia, CHARLOTTESVLE, Virginia, United States

Co-registered axial helium-3 short-time-scale (STS) and long-time-scale (LTS) ADC maps were measured in 24 healthy subjects, 34 second-hand smokers, 15 patients with COPD and 14 patients with asthma. Compared with healthy subjects: (1) both STS and LTS ADC were elevated for patients with COPD; (2) STS ADC was elevated while LTS ADC was not for second-hand smokers; and (3) LTS ADC was elevated while STS ADC was not for asthmatics. These findings suggest that STS and LTS ADC are measuring different aspects of the structural changes that occur in the lung with exposure to second-hand smoke and asthma.

Peter Komlosi¹, Talissa A. Altes¹, Kun Qing¹, G. Wilson Miller¹, Jaime F. Mata¹, Gordon D. Cates Jr.², Eduard E. De Lange¹, and John P. Mugler, III^1
1Department Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States, ²Department of Physics, University of Virginia, Charlottesville, VA, United States

Histologic studies of the lung have demonstrated that alveolar ducts emanating from terminal bronchioles near the pleural surface show a preferential orientation perpendicular to the pleural surface, in contrast to deeper regions. The goal of the present study was to evaluate whether the dependence of He3 ADC values on the direction of the diffusion-sensitization gradient is sufficiently sensitive to detect subtle microstructural variations such as those near pleural surfaces. Diffusion-weighted measurements along three orthogonal diffusion-sensitization directions demonstrated increased ADC values when the sensitization direction was perpendicular to the plural surface.

Roberta Santarelli¹, Marion Tardieu¹, Ralph Sinkus², Pierre-Yves Brillet³, Luc Darrasse¹, and Xavier Maître^1
1IR4M, Université Paris sud-XI, Orsay, Ile de France, France, ²Centre de Recherches Biomédicales Bichat-Beaujon, Paris, Ile de France, France, ³3Réponses Cellulaires et Fonctionnelles à l'Hypoxie, Bobigny, Ile de France, France

The mechanical properties of lung tissue play a key role in the basic function of the organ. They could be very sensitive pulmonary biomarkers as they are dramatically altered by most lung diseases. Currently available imaging modalities fail to regionally probe them in-vivo. Initiated in 1995, MR-elastography was recently implemented on a tracer gas, hyperpolarized helium-3, to explore the viscoelastic properties of the lung. This work demonstrates the feasibility in vivo of helium-3 MR-elastography in small animal and human lungs with extracted mean dynamic shear moduli of (0.72±0.002) kPa and (1.83±0.02) kPa, respectively and corresponding mean loss shear moduli of (0.16±0.003) kPa and (0.25±0.008) kPa. This opens up promising insights into diseased lungs in patients suffering from emphysema, fibrosis, or cancer.

Maxim Terekhov¹, Klaus Gast², Manuela Gueldner³, Julien Rivoire¹, Ursula Wolf², Janet Friedrich¹, Sergej Karpuk³, and Laura Maria Schreiber^1
1Department Radiology, Section of Medical Physics, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany, ²Department of Radiology, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany, ³Institute of Physics, Johannes Gutenberg University, Mainz, Germany

Dynamic Ventilation of lung measured with hyperpolarized 3He-MRI (3He-DV-MRI) is an efficient tool to obtain information on temporal and spatial distribution of gas in lung airways and parenchyma, that is of great importance for the diagnostics of airways obstructions e.g. asthma and COPD. We performed systematic study and analysis of correlations and reproducibility between the parameters of applied 3He-bolus and gas delivery as measured by 3He-DV-MRI. The study was done on n=10 healthy volunteers with flow-controlled gas administration using custom-built application unit (AU). To our knowledge this is one of the first studies with validation of 3He-DV-MRI by the volumetry data on a large group of volunteers.

Xiaojun Xu¹, General Leung¹, Graham Norquay¹, Helen Marshall¹, Juan Parra-Robles¹, and Jim M. Wild^1
1Academic Radiology, University of Sheffield, Sheffield, South Yorkshire, United Kingdom

¹²⁹Xe gas is soluble in blood and tissue with a large observable chemical shift that can be utilized to image and quantify gas exchange in the lungs. Knowing the in vivo relaxation constants is important in determining sequence parameters for optimal dissolved phase ¹²⁹Xe imaging. The measurement of the T₂^* of dissolved phase ¹²⁹Xe in human lungs at 1.5 T and 3 T are presented.

Nicholas J. Tustison¹, Alicia Muratore¹, Benjamin Contrella¹, John P. Mugler, III¹, Eduard E. De Lange¹, and Talissa A. Altes^1
1Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, United States

We compare hyperpolarized He-3 and Xe-129 imaging in patients with cystic fibrosis patients. Computational assessment demonstrates increased ventilation in the He-3 images with a possible explanation being that the higher diffusivity of helium-3 allows more helium than xenon to enter regions of partial airflow obstruction, while areas with complete airflow obstruction appear the same.

Yulin V. Chang¹, James D. Quirk², Iulian C. Ruset³, Jeffrey J. Atkinson⁴, F. William Hersman³, and Jason C. Woods^2
1Radiology, Washington University in Saint Louis, St. Louis, MO, United States, ²Radiology, Washington University, St. Louis, MO, United States, ³Xemed LLC, Durham, NH, United States, ⁴Department of Medicine, Washington University, St. Louis, Missouri, United States

Xenon-129 is a unique contrast agent in lung MRI because of its solubility in lung tissue and blood. Hyperpolarized 129Xe gives high MRI signals that allow detection of the uptake of dissolved-129Xe in the lung. It has been previously demonstrated that the uptake dynamics of xenon can be used for quantification of lung function. In this work we present our first in-human study to quantify lung function and structure using dissolved hyperpolarized 129Xe dynamics. We show that by using our previously developed model of xenon exchange we can measure a range of critical pulmonary parameters, including septal wall thickness, surface-area-to-volume ratio, etc.

Yoshimitsu Ohgiya¹, Hiroshi Nobusawa², Noritaka Seino¹, Makoto Saiki¹, Yui Onoda¹, Jumpei Suyama¹, Masanori Hirose¹, and Takehiko Gokan^1
1Department of Radiology, Showa University School of Medicine, Tokyo, Japan, ²Department of Radiology, Kawasaki saiwai hospital, Kawasaki-shi, Kanagawa-ken, Japan

The purpose of this study was to evaluate morphologic and signal intensity changes of placental insufficiency on MR imaging and to assess value of morphologic changes and decreased flow voids (FVs) on T2-weight RARE MR imaging for diagnosing placental insufficiency. The use of decreased FVs in addition to globular appearances increased sensitivity for the detection of placental insufficiency from 76.0% to 88.0%, increased accuracy from 78.0% to 82.0%, and preserved specificity at 76.0%. Evaluating FVs on T2-weighted RARE images can be useful for detecting placental insufficiency, particularly in placentas without globular appearances on MR imaging.

Yukihisa Takayama¹, Akihiro Nishie², Osamu Togao¹, Yoshiki Asayama², Yasuhiro Ushijima², Nobuhiro Fujita², Takashi Yoshiura², Makoto Obara³, Jochen Keupp⁴, and Hiroshi Honda^2
1Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan, ²Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan, ³Philips Electronics Japan, Tokyo, Tokyo, Japan,⁴Philips Technologie GmbH Forschungslaboratorien, Hamburg, Germany

In this study, we investigated the feasibility of CEST imaging for the assessment of uterine tumors; endometrial carcinoma (EMCA) and squamous cell carcinoma (SCC). Our results showed that the spectra of MTRasym of EMCA were significantly higher than those of SCC at from 2.2 ppm to 3.7 ppm and from 4.8 ppm to 5.1 ppm. In addition, amide proton transfer (APT) map showed that APT ratio of EMCA was significantly higher than that of SCC. CEST imaging of uterine tumor may be feasible in clinical practice because this imaging can provide molecular information such as histological characteristics.

Mayumi Takeuchi¹, Kenji Matsuzaki¹, and Masafumi Harada^1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

We evaluated the relationship between MR biomarkers (ADC value on DWI and metabolite concentration on MRS), and prognostic factors (tumor grade and depth of myometrial invasion) of 56 malignant endometrial tumors including 39 low grade tumors and 17 high grade tumors. There was no statistically significant difference in ADC values and choline concentration between tumor grades, or depth of myometrial invasion. Necrosis-associated lipid peak is observed in all 17 high grade tumors (100%) but in 17 of 39 low grade tumors (44%). It may be suggested that no lipid peak is suggestive for relatively low grade endometrial tumors.

Rong Rong¹, Juan Wei², Xuedong Yang¹, Jing Liu¹, Ying Zhu¹, Bilgin Keserci³, and Xiaoying Wang^1
1Radiology Department, Peking University First Hospital, Beijing, China, ²Philips Research Asia, Shanghai, China, ³Philips Healthcare South Korea, Seoul, Korea

Hypervascular fibroids are difficult to treat because the blood vessels effectively carry heat away from the treatment area, resulting in subtherapeutic temperatures within the target tissue in MR-guided focused ultrasound ablation. So it is important to differentiate type 3 fibroids. Perfusion fraction and diffusion coefficient derived from different b-value combinations reflect vascularity and perfusion in different types of fibroids and will help to differentiate type 1, type 2 and type 3 fibroids, especially the type 3 fibroids. This may improve the accuracy of MR screening before MR-guided focused ultrasound Ablation and will help to exclude the type 3 fibroids.

Uday Krishnamurthy¹, Yimin Shen², Gabor Szalai³, Jaladhar Neelavalli², Bing Wang³, Tinnakorn Chaiworapongsa^3,4, Edgar Hernandez-Andrade^3,4, Nandor Gabor Than^3,4, Ewart Mark Haacke², and Roberto Romero^3
1Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, United States, ²Department of Radiology, Wayne State University, Detroit, Michigan, United States, ³Perinatology Research Branch, NICHD, NIH, DHHS, Wayne State University, Detroit, Michigan, United States,⁴Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, United States

Using susceptibility weighted imaging (SWI),we have shown that there is significant correlation between venous phase in the umbilical artery and the phase measured from the corresponding lungs and placenta, indicating that phase measurements from the fetal lung or placenta can be used for assessing relative fetal blood oxygenation in mouse pregnancy

Jin Yamamura¹, Chressen K. Much¹, Manuela Tavares de Sousa², Friedrich Ueberle³, Hendrik Kooijman⁴, Gerhard Adam¹, Ulrike Wedegärtner¹, and Björn P. Schönnagel^1
1Diagnostic and Interventional Radiology, University Medical Center-Hamburg, Hamburg, Hamburg, Germany, ²Obstetrics and Fetal Medicine, University Medical Center-Hamburg, Hamburg, Hamburg, Germany, ³Hamburg University of Applied Sciences, Hamburg, Hamburg, Germany, ⁴Philips Medical Systems, Hamburg, Hamburg, Germany

Antenatal blood flow quantification by Phase-contrast MRI using a new triggering method: Comparison with Doppler Ultrasound measurements in a sheep model

Mayumi Takeuchi¹, Kenji Matsuzaki¹, and Masafumi Harada^1
1Department of Radiology, University of Tokushima, Tokushima, Tokushima, Japan

We evaluated MR manifestations including DWI of 11 ovarian thecomas/fibrothecomas and compared with those of 12 non-thecomatous benign tumors and 51 primary malignant ovarian tumors. All thecomas/fibrothecomas showed totally or partially low intensity on T2-weighted images and high intensity on DWI, whereas none of non-thecomatous benign tumors show high intensity on DWI, and only one of 51 malignant tumors show partially low intensity on T2-weighted images. The ADC value (x 10-3 mm2/seconds) of thecomas/fibrothecomas (1.16 +/- 0.07) is significantly higher than that of malignant tumors (1.05 +/- 0.18) (p=0.01), and lower than that of benign tumors (1.44 +/- 0.24) (p=0.001).

Joshua F. P. van Amerom^1,2, Christopher W. Roy³, Milan Prsa², John C. Kingdom⁴, Christopher K. Macgowan^2,3, and Mike Seed^1,2
1Labatt Family Heart Centre, Div. of Cardiology, Dept. of Paediatrics, Hospital for Sick Children, Toronto, ON, Canada, ²Dept. of Diagnostic Imaging, Hospital for Sick Children, Toronto, ON, Canada, ³Dept. of Medical Biophysics, University of Toronto, Toronto, ON, Canada, ⁴Dept. of Obstetrics and Gynaecology, Maternal-Fetal Medicine Div., Mount Sinai Hospital, Toronto, ON, Canada

Redistribution of blood flow in late-onset fetal growth restriction was assessed in utero using phase contrast MR, and compared with Doppler. MR flows showed increased cerebral blood flow, in keeping with the concept of “brain sparing physiology”.

Devasuda Anblagan¹, Nia W. Jones², Carolyn Costigan¹, Ruta Deshpande², Nick Raine-Fenning³, George Bugg², Zdenka Pausova^4,5, Tomas Paus^6,7, and Penelope A. Gowland^1
1Sir Peter Mansfield Magnetic Resonance Centre, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ²Nottingham University Hospitals NHS Trust, Nottingham, Nottinghamshire, United Kingdom, ³Division of Obstetrics & Gynaecology, School of Clinical Sciences, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom, ⁴Research Institute of the Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada, ⁵Universite de Montreal, Montreal, Quebec, Canada, ⁶Rotman Research Institute, University of Toronto, Toronto, Ontario, Canada, ⁷School of Psychology, University of Nottingham, Nottingham, Nottinghamshire, United Kingdom

High volume, low resistance blood flow in the placenta is thought to be essential for fetal growth and development and is impaired by maternal smoking. Using intravoxel incoherent motion (IVIM) we assessed placental blood flow in pregnant smokers and controls. Blood flow was significantly increased and diffusion decreased in the chorionic plate with gestational age, with similar trends for the basal plate and placenta. Basal plate blood-flow was higher in smokers at mid-gestation, which would be consistent with impaired placental implantation, possibly related to the up-regulation of vascular growth factors by nicotine.

Shaza AlSharif¹, Stephanie Nougaret¹, Helen Addley², Jocelyne Arseneau¹, Evis Sala², and Caroline Reinhold^1
1Radiology, McGill University, Montreal, QC, Canada, ²Radiology, University of Cambridge, Cambridge, United Kingdom

Endometrial Carcinoma: Staging Accuracy of Diffusion Weighted Images

Fuki Shitano¹, Aki Kido¹, Masako Kataoka¹, Koji Fujimoto², Kayo Kiguchi¹, Kyoko Takakura¹, Yuki Himoto², and Kaori Togashi^1
1Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Kyoto, Japan, ²Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, Kyoto, Kyoto, Japan

Uterine peristalsis has been evaluated using cine MRI, but it was only at sagittal plane. We tried to evaluate this movement both on sagittal and coronal plane on 3T at pre-ovulation usinig cine MR. There were no significant differences in frequency of peristaltic waves between each walls of sagittal and coronal plane. However, peristaltic direction and outer myometrial conduction of low signal intensity were more recognized in coronal plane than sagittal plane. Although there may be no relation between laterality of ovulation and peristaltic movement, more population is necessary for evaluation.

Pavan Kumar Jella¹, Jaladhar Neelavali², Uday Krishnamurthy¹, Swati Mody², Lami Yeo^3,4, Yashwanth Katkuri², Ray O. Bahado-Singh⁵, Sonia Hassan^3,4, Haacke Mark Ewart², Robert Romero⁴, and Moriah Thomason^4,6
1Biomedical Engineering, Wayne state university, Detroit, MI, United States, ²Department of Radiology, Wayne State University, Detorit, MI, United States,³Department of Obstetrics and Gynecology, Wayne state university, Detroit, MI, United States, ⁴Perinatology Research Branch, Wayne State University, Detroit, MI, United States, ⁵Department of Obstetrics and Gynecology, Wayne state university, Detorit, MI, United States, ⁶Department of Pediatrics, Wayne State University, Detroit, MI, United States

We measured fetal cerebral blood oxygenation in 5 normal fetuses at varying gestational ages using MR susceptibility weighted imaging.

Feng Wang^1,2, Zhongliang Zu^1,2, Keiko Takahashi³, John C. Gore^1,2, Raymond C. Harris³, Takamune Takahashi³, and Christopher C. Quarles^1,2
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ³O'Brien Mouse Kidney Physiology and Disease Center, Vanderbilt University, Nashville, TN, United States

Chemical exchange saturation transfer (CEST) and magnetization transfer (MT) imaging are sensitive to small molecules with exchangeable protons and macromolecules, respectively. Such methods could complement the physiological information obtained from conventional assays of kidney function and facilitate our understanding of pathological mechanisms in kidney disease. In this study, we used CEST and MT to assess mouse kidney following unilateral ureter obstruction (UUO) to determine if these methods are sensitive to the associated pathology.

Lu-Ping Li¹, Jon Thacker¹, Tammy Franklin¹, Hongyan Du², Anindya Sen¹, Maria Papadopulou-Rosenzweig³, Richard Solomon⁴, and Pottumarthi Vara Prasad^1
1Radiology, Northshore University Healthsystem, Evanston, IL, United States, ²Center for Clinical & Research Informatics, Northshore University Healthsystem, Evanston, IL, United States, ³Radiation Medicine, Northshore University Healthsystem, Evanston, IL, United States, ⁴Nephrology, University of Vermont, Burlington, VT, United States

A prospective, randomized, blinded study was performed to compare the efficacy of two protective interventions (administration of loop diuretic furosemide and antioxidant n-acetyl cysteine (NAC)) in a rat model of contrast-induced nephropathy (CIN). Studies were performed with three different contrast media. Our data with BOLD MRI measurements show that diuretic furosemide resulted in reduced enhancement in R2* post-contrast media while NAC resulted in no appreciable change compared to the control group. Further studies to confirm that the reduced hypoxia leads to reduced CIN with additional direct markers or renal injury are necessary.

Xiufeng Li¹, Patrick J. Bolan¹, Kamil Ugurbil¹, and Gregory J. Metzger^1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

Knowledge of renal longitudinal magnetization relaxation time is essential in renal imaging protocol optimization and quantitative non-contrast enhanced renal perfusion imaging using arterial spin labeling at 7T. Previous studies have indicated that, compared to T2 and spin density, the longitudinal relaxation time can be more important in characterizing renal diseases and differentiating specific disease states. For the first time, renal longitudinal relaxation times have been measured at 7T in healthy normal volunteers. The reproducibility of renal T1 measurements was also evaluated with repeated studies in two sessions approximately one week apart.

Feng Wang^1,2, David A. Hormuth, II^1,3, Keiko Takahashi⁴, John C. Gore^1,2, Raymond C. Harris⁴, Takamune Takahashi⁴, and Christopher C. Quarles^1,2
1Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ³Biomedical Engineering, Vanderbilt University, Nashville, TN, United States, ⁴O'Brien Mouse Kidney Physiology and Disease Center, Vanderbilt University, Nashville, TN, United States

Renal function is highly dependent upon adequate perfusion and oxygenation and their non-invasive assessment in mice could provide useful tools with which to interrogate disease models. Recently, an experimentally practical quantitative BOLD approach (qBOLD) was proposed that enables the quantification of local blood oxygen saturation (LSO2) [1]. In this study, we evaluated the feasibility of this qBOLD protocol for application to mouse kidneys. Specifically, we optimized imaging sequences and protocols that enable mapping of T2, T2* (before and after the injection of a contrast agent), blood volume fraction (BVf) and Bo.

Nanda Deepa Thimmappa¹, Michelle Ann C. Cerilles¹, Allison Dunning², Stephanie Donahue³, Honglei Zhang¹, Jon D. Blumenfeld^3,4, and Martin R. Prince^1
1Radiology, Weill Cornell Medical College, New York, NY, United States, ²Dept of Statistics, Weill Cornell Medical College, New York, NY, United States,³Nephrology, The Rogosin Institute, New York, NY, United States, ⁴Nephrology, Weill Cornell Medical College, New York, NY, United States

Prominent cisterna chyli are found on T2-weighted MRI in patients with autosomal dominant polycystic kidney disease but not in age and gender-matched controls. There were also significant associations with biomarkers of kidney disease severity including larger cisterna chyli with increasing Total Kidney Volume, increasing liver volume and decreasing eGFR.

Dinah S. Khatir¹, Niels H. Buus¹, and Michael Pedersen^2
1Department of Nephrology, Aarhus University Hospital, Aarhus, Denmark, ²MR Research Center, Aarhus University Hospital, Aarhus, Denmark

The objective of this study was to evaluate the reproducibility of measurements of renal artery blood flow (RABF) and intrarenal oxygenation (BOLD), using R2*, in patients (n=11) with chronic kidney disease (CKD) and healthy controls (n=9). This study showed that RABF and renal-cortical BOLD MRI were reproducible in both healthy volunteers and patients with CKD and hypertension. Furthermore, we found that inhalation of 100% oxygen significantly increased R2* in renal medulla in both groups. RABF and R2* measurements may serve as an sensitive biomarker for hemodynamic monitoring in CKD patients suffering from hypertension.

Stefan Zbýn¹, Vladimir Juras¹, Henrik J. Michaely², Xeni Deligianni³, Oliver Bieri³, Stefan O. Schoenberg², Siegfried Trattnig¹, and Stefan Haneder^2
1MR Center of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria, ²Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany, ³Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland

In this study, we employed high SNR provided by 7T for the in vivo measurements of cortico-medullary gradient in human kidneys for the first time. Compared to previous human kidney studies with nominal voxel sizes of 0.135-0.125 mL at 3T, the nominal voxel size was decreased to 0.080 mL and the image quality was improved at 7T. A steeper slope of corticomedullary gradient was observed at 7T compared to 3T. This study showed for the first time the feasibility of in vivo 23Na MRI of human kidneys at 7.0T using vTE-GRE sequence and confirmed the presence of corticomedullary gradient.

KS Winter¹, Michael Ingrisch¹, Michael Staehler¹, Andreas D. Helck¹, Margarita Braunagel¹, Maximilian F. Reiser¹, Konstantin Nikolaou¹, and Mike Notohamiprodjo^1
1University Hospitals Munich, Munich, Bavaria, Germany

The aim of this study was to compare single-slice MR-Renography with measurements of the whole organ. 15 MR-Renography measurements with 30 kidneys were included. The results show no significant differences between single slice and whole organ FP, VP and GFR and correlation was excellent for all parameters (r>0.95). However single slice results were slightly higher than for the whole organ measurements. Based on magnetic field inhomogeneity there was a significant gradient between ventral and dorsal slices for FP, VP and GFR in analysis based absolute enhancement. In conclusion single slice MR-Renography is representative for the whole organ.

Stefan Zbýn¹, Vladimir Juras¹, Henrik J. Michaely², Xeni Deligianni³, Oliver Bieri³, Stefan O. Schoenberg², Siegfried Trattnig¹, and Stefan Haneder^2
1MR Center of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria, ²Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany, ³Division of Radiological Physics, Department of Radiology, University of Basel Hospital, Basel, Switzerland

All previous reports on (sodium) 23Na T2* relaxation times in the kidneys were measured in animals and revealed slightly different values. In this study, we employed high SNR provided by 7T for the in vivo measurements of T2* relaxation times in human kidneys for the first time. Our T2* results are in good agreement with long T2* components published before. Moreover, similarly to the results from animal studies, we observed shorter T2* values in renal cortex compared to medulla. This data may provide the basis for absolute quantification of 23Na content in human kidneys.

Jian Dong¹, Li Yang², Tao Su², Xiaoying Wang¹, and Xuexiang Jiang^1
1Radiology, Peking University First Hospital, Beijing, Beijing, China, ²Nephrology, Peking University First Hospital, Beijing, Beijing, China

Acute kidney injury (AKI) is a frequent event, with the incidence of more than 5000 for non-dialysis therapy and 295 for dialysis treatment per million people per year.Diffusion-weighted (DW) MR is a functional imaging technique providing quantitative parameters of diffusion and microcirculation in tissues based on the apparent diffusion coefficient (ADC).This study is to investigate the feasibility of DW MR imaging in the diagnosis and therapeutic effect of AKI.The results of our study show DW MR imaging can help detect the differences in the AKI kidney.DW MR imaging is a feasible imaging tool to depict early alterations in AKI, with a potential capability to reflect prognosis.

Marta E. Heilbrun¹, Kathryn A. Morton², Lei Zhang³, Christopher C. Conlin⁴, Pierre-Hughes Vivier⁵, and Vivian S. Lee^6
1Radiology, University of Utah, Salt Lake City, UT, United States, ²Univ of Utah, Salt Lake City, UT, United States, ³UCAIR, Univ of Utah, Salt Lake City, UT, United States, ⁴UCAIR, University of Utah, Salt Lake City, UT, United States, ⁵Department of Radiology, Rouen University Hospital, Rouen, France,⁶University of Utah, Salt Lake City, UT, United States

Low dose MR renography appears to measure renal function well in cirrhotics, and may perform better than the MDRD calculation.

Camilo James¹, Kassa Darge^1,2, Dmitry Khirchenko¹, Rob Carson¹, and Jeffrey I. Berman^1,2
1Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States, ²Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States

Indicators of both the structure and function of the pediatric kidney are necessary to differentiate pelvicalyceal dilatations requiring surgery from cases that do not. This study evaluates the feasibility of DTI assessment of normal and abnormal pediatric kidney structure and compares to functional MR urography (fMRU) metrics. DTI of the kidney and contrast-enhanced fMRU was performed at 3T in nine children (6 boys, 3 girls) with a mean age of 4.3 years (range 0.5-14.8 years). DTI and tractography metrics were observed to correlate with parenchyma region and kidney function, suggesting the potential use of tractography as a clinical tool.

Arash Latifoltojar¹, Paul Humphries¹, Ananth Shankar², Stephen Daw², Stuart Taylor¹, and Shonit Punwani^1
1Centre for Medical Imaging, UCL, London, London, United Kingdom, ²UCL, London, London, United Kingdom

Whole body MRI is an emerging technique in oncological imaging. With recent advances in MR imaging, functional imaging such as diffusion weighted imaging (DWI) can complement the conventional T1 and T2 weighted MRI. Whole body diffusion weighted imaging (WB-DWI) could potentially be implemented as a safe alternative to the current gold standard whole body imaging, PET-CT.

Anwar R. Padhani¹, Hemmy K. Sokhi¹, and Andres Gogbashian^1
1Paul Strickland Scanner Centre, Mount Vernon Cancer Centre, Northwood, Middlesex, United Kingdom

Knowledge of the spectrum of pitfalls, unexpected and unusual findings and artifacts on whole body diffusion imaging will enable image support scientists, technologists and radiologists to effectively use this emerging clinical technique for disease detection and response assessments in patients with known cancers.

Nan-Jie Gong¹, Chun-Sing Wong¹, Yiu-Ching Chu², Bingsheng Huang¹, and Queenie Chan^3
1Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China, ²Radiology, Kwong Wah Hospital, Hong Kong, China,³Philips Healthcare, Hong Kong, China

To more precisely segment high-cellularity tumor tissues in heterogeneous lesions and therefore more accurately measure volumes and ADCs, we proposed a semi-automatic method based on thresholding both the b0 images and the ADC maps. Using k-means clustering algorithm, B0 images and ADC maps in the contoured regions were separately classified into three clusters (with low, intermediate and high value). The pixels with low intensities on b0 images and those with high ADC values on ADC maps were excluded, leaving only the probable high-cellularity tumor tissues. The volumes measured using the proposed method had perfect concordance with those in PET/CT. Furthermore, stronger correlations between ADC values and SUV values were achieved using this method.

Matthew D. Blackledge¹, Nina Tunariu¹, David John Collins¹, Anwar R. Padhani², Martin O. Leach¹, and Dow M. Koh^1
1CRUK and EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom, ²Paul Strickland Scanner Centre, Mount Vernon Hospital, Northwood, Middlesex, United Kingdom

We derive the intra-observer repeatability (Bland-Altman statistics) of two radiologists reporting median ADC and total diffusion volume estimates derived from whole-body diffusion-weighted imaging (WBDWI) in a cohort of nine patients with bone metastases. Good repeatability in the range -13.5 to 15.6% is found for ADC estimates and -44.2% to 79.3% for volume estimates. Clinical changes of these parameters in response to treatment are shown to be greater than the repeatability limits observed, as demonstrated in a pilot cohort of 13 patients with bone metastases.

Christina Messiou¹, Sharon L. Giles¹, David John Collins^1,2, Faith E. Davies^3,4, Gareth Morgan^3,4, and Nandita M. deSouza^1,2
1MRI Department, Royal Marsden Hospital, Sutton, Surrey, United Kingdom, ²Clinical Magnetic Resonance, Institute of Cancer Research, Sutton, Surrey, United Kingdom, ³Haemato-oncology Department, Royal Marsden Hospital, Sutton, Surrey, United Kingdom, ⁴Molecular Pathology, Institute of Cancer Research, Sutton, Surrey, United Kingdom

Whole body diffusion-weighted MRI (WB-DWI) offers an alternative to serum paraproteins and bone trephine for staging and response assessment of myeloma particularly due to its quantitative capabilities. This prospective study compared mean ADCs and histogram characteristics of marrow from whole spine, bony pelvis, femora and sternum between normal volunteers and patients with myeloma and between those with low as opposed to high burden of disease. Mean ADC and ADC histogram characteristics were significantly different between normal volunteers and myeloma patients and in those with a low compared to high disease burden making WB-DWI a promising quantitative technique for disease staging.

Christopher Nguyen^1,2, Zhaoyang Fan¹, Behzad Sharif¹, Rohan Dharmakumar¹, Rola Saouaf³, Hyung L. Kim⁴, and Debiao Li^1,2
1Biomedical Imaging Research Institute, Cedars Sinai Medical Center, Los Angeles, CA, United States, ²Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States, ³Radiology, Cedars Sinai Medical Center, Los Angeles, CA, United States, ⁴Urology, Cedars Sinai Medical Center, Los Angeles, CA, United States

Abdominal diffusion MRI has the potential to characterize benign or malignant tumors in various organs. Magnetic susceptibility, low SNR, and low spatial resolution have been the primary challenges for the conventional DW SS EPI. We propose a novel application of Diffu-prep bSSFP to yield high resolution, high SNR, and low distortion DW images of the kidneys. ADC values acquired from 9 volunteers are consistent with prior in vivo human renal diffusion studies and DW SS EPI derived values. The multi-shot bSSFP readout has the potential to offer better image quality, higher resolutions, and higher SNR over conventional EPI-based sequences while maintaining the quantitative power of diffusion MRI.

Maryam Seif¹, Huanxiang Lu², Chris Boesch¹, Mauricio Reyes², and Peter Vermathen^1
1Depts Clinical Research and Radiology, University Bern, Bern, Switzerland, ²Institute for Surgical Technology and Biomechanics, University Bern, Bern, Switzerland

Abdominal DTI is sensitive to respiration motion artifacts and even in triggered scans residual motion artifacts remain. Our previous study demonstrated that non-rigid image co-registration of individual DTI images of human kidney reduces the residual motion artifacts in triggered scans. Based upon our precedent encouraging results the aim of this study was therefore to employ prior to further analysis the non-rigid image co-registration in non-triggered DTI scans. The co-registration results visually revealed less distortion within the kidney and additionally a significant decrease of RMSE (p<0.05) was obtained after co-registration for triggered and also for non triggered scans.

Sharon L. Giles¹, Catherine J. Simpkin¹, David John Collins^1,2, Christina Messiou¹, and Nandita M. deSouza^1,2
1MRI Department, Royal Marsden Hospital, Sutton, Surrey, United Kingdom, ²Clinical Magnetic Resonance, Institute of Cancer Research, Sutton, Surrey, United Kingdom

WB-DWI is emerging as a quantitative tool to assess treatment response in myeloma but changes in ADC indicative of response may be relatively small and analysis methods remain without consensus. This prospective study investigated the reproducibility, intra- and inter-observer variability of a volumetric segmentation technique in a cohort of healthy volunteers. Reproducibility of the ADC measurement was between 0.3% and 9.2% and the segmentation technique used provided a consistent and reliable method to generate ADC histograms. It did not introduce additional variation across or between observers and is therefore of potential value in clinical assessment of treatment response in myeloma.

Tetsuo Ogino^1,2, Toshiaki Miyati³, Marc Van Cauteren⁴, Tomohiko Horie⁵, and Yutaka Imai^6
1Healthcare department, Philips Electronics Japan, LTD, Minato-ku, Tokyo, Japan, ²Division of Health Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan, ³Kanazawa University, Kanazawa, Ishikawa, Japan, ⁴Philips Healthcare LTD, Minato-ku, Tokyo, Japan, ⁵Dept. of Radiology, Tokai University Hospital, Isehara, Kanagawa, Japan, ⁶Radiology, Tokai University, Isehara, Kanagawa, Japan

A novel method to combine Breath holding, cardiac triggering and double bipolar diffusion gradient is proposed to improve reproducibility of liver ADC measurement. With conventional respiratory triggering DWI, left lobe of liver ADC is artificially elevated by cardiac motion and suffer from poor reproducibility. The proposed method eliminating the cardiac motion effect reduced left/right lobe normal parenchyma ADC difference to 3% from 70 % of conventional respiratory triggering method. 20 slices were acquired with 4 inspiration breath holdings of 10-20 seconds duration. It allows uniform and reproducible ADC measurement in clinically feasible scan time.

Jessica M. Winfield¹, Naomi H. M. Douglas¹, David John Collins¹, and Nandita M. deSouza^1
1Institute of Cancer Research, Sutton, Surrey, United Kingdom

We present a test-object for assessment of fat suppression across a large field of view in diffusion-weighted-MRI (DW-MRI). The test-object is a Perspex cylinder (diameter 185 mm, height 300 mm) filled with corn oil and inner water-filled cylinder (140 mm). We demonstrate that corn oil is suitable for investigation of spectrally-selective and T1-dependent methods. We have used the test-object to develop techniques to suppress signals from saturated and unsaturated components of fat at 1.5 T and 3 T. Suppression of both components of the fat signal is particularly relevant in DW-MRI studies of tissues containing fat, for example bone marrow.

He Wang¹, Naiyi Zhu², Fuhua Yan², Guang Cao³, and Xu Yan^4
1MR Research China, GE Healthcare, Shanghai, China, ²Department of Radiology, Ruijin Hospital, Shanghai, China, ³GE Healthcare, Shanghai, China, ⁴East China Normal University, Shanghai, China

Diffusional kurtosis imaging has shown promising results in studies of human brain aging and brain tumor characterization, however, limited results were reported on liver diseases. This study is to investigate the clinical feasibility of DKI in evaluating liver fibrosis by comparison with serum fibrosis indicators. As a result, FA MD, Da and Dr exhibited statistically significant correlation with LN. In addition, compared with another serum indicator HBsAg, moderate correlations were found in Da, MK and Ka. Kurtosis parameters had stronger correlations with HBsAg than normal diffusion parameters.

Gaspar Delso¹, Sangwoo Lee², Miguel Porto¹, and Patrick Veit-Haibach^1
1UniversitätsSpital Zürich, Zürich, Switzerland, ²GE Healthcare, Seoul, Korea

Intravoxel incoherent motion (IVIM) imaging can be used to quantify the influence of microscopic perfusion-related motion on diffusion-weighted images (DWI) and differentiate it from pure molecular diffusion. IVIM has the potential to provide valuable clinical information about the microcirculation in the capillary network of malignant body tumors. This information holds great value for the determination of tumor viability as well as the prediction of therapy outcome. In order to determine the diffusion and perfusion parameters, a sequence of DWI acquisitions with increasing diffusion-sensitizing gradient magnitude is acquired. A model of the influence of diffusion and perfusion on the signal intensity is then fitted to this sequence. The quality of the final result is, therefore, very sensitive to deviations from the model, such as those caused by patient motion between the acquisitions. We study here the use of robust regression techniques to enable IVIM analysis in the presence of outliers, like those caused by physiological motion, when imaging lesions in the thorax and upper abdomen. Concurrent Positron Emission Tomography information is used to validate the results.

Naomi H. M. Douglas¹, Jessica M. Winfield¹, Nandita M. deSouza¹, David John Collins¹, and Matthew R. Orton^1
1Radiotherapy and Imaging, Institute of Cancer Research, Sutton, Surrey, United Kingdom

Temperature-controlled phantoms containing controlled sucrose solutions were used to measure the Apparent Diffusion Coefficient at five European imaging centres. Matched Diffusion-Weighted (DW) MR sequences were applied across three scanner manufacturers. Repeat measurements were acquired over a 6-month period. Inter-site comparison revealed differences in scanner accuracy, precision and stability. Artefacts were identified including spatial variations in ADC of a uniform test object, prompting a recommendation that reproducible subject positioning is ensured in tests of diffusion parameter reproducibility. Results from systems without identifiable artefact suggest that an ADC coefficient of variation of less than 2% is achievable with well controlled scanner set-up.

Sonia Isabel Goncalves^1,2, Filipe Caseiro Alves^1,2, and Miguel Castelo Branco^1,3
1Medical Faculty, University Coimbra, Coimbra, Coimbra, Portugal, ²Radiology, University Hospital Coimbra, Coimbra, Coimbra, Portugal, ³Biomedical Institute for Research in Light and Image, University of Coimbra, Coimbra, Coimbra, Portugal

Intra-voxel incoherent motion (IVIM) imaging differentiates between true molecular diffusion or slow diffusion (D), diffusion due to perfusion or fast diffusion (D*), and quantifies perfusion fraction (f). IVIM imaging has been applied to characterize and stage, in a non-invasive way, several pathological changes of the liver. Recently, methods have been proposed to optimize b-value distribution so that the errors associated with D, D* and f are minimized. In this paper, we hypothesize that different perfusion regimes will have different error behavior associated with D, D* and f and that T2 relaxation effects will have an impact on the error behavior of the optimal b-value distribution.

Jochen G. Hirsch^1,2, Alto Stemmer³, Berthold Kiefer³, and Matthias Guenther^1,2
1University of Bremen, Bremen, Bremen, Germany, ²Fraunhofer MEVIS, Bremen, Bremen, Germany, ³SIEMENS AG Healthcare Sector, Erlangen, Bavaria, Germany

We propose an imaging method for diffusion-weighting (DW) in clinical body applications using the continuously moving table (CMT) approach with sliding multislice (SMS). In contrary to previous approaches that use a single-slice CMT STIR-DW acquisition, we developed a sliding multislice-multishot scheme with SPAIR preparation for effi¬cient and clinically acceptable scan times offering multiple b-values for DW as well as multiple averages for increased signal-to-noise ratio (SNR). This new CMT DW EP sequence is compared to an established static multistation DW proto¬col clinically used in body applications with respect to diffusion weighting, SNR, artifacts, and scan times.

Yanqing Xu¹, Li Wang¹, Zhongwei Qiao¹, and Ed X. Wu^2
1Department of Radiology, Children Hospital of Fudan University, Shanghai, China, ²EEE of Department, Hong Kong University, Hong Kong, China

Little was known about the perfusion-related diffusion and true diffusion in pediatric abdominal tumor. This study aims to investigate the D, D* and f in pediatric abdominal tumors by using IVIM DW-MRI. Our results showed that there were no difference in ADC, D, D* and f of neuroblastoma and Wilms¡¯ tumor.Perfusion-related diffusion was observed in malignant and benign tumors, however there was a low D in malignant tumor compared to benign tumor.

Yang Wen¹, Guangheng Yin¹, Yue Zhang¹, and Yun Peng^1
1Imaging Center, Beijing Children's Hospital, Capital Medical University, Beijing, China

Purpose: To determine whether apparent diffusion coefficients (ADC) of the neuroblastic tumors and signal intensity on diffusion-weighted (DW) images allow differentiation of neuroblastoma, ganglioneuroblastoma and ganglioneuroma. Materials and Methods: Approval for this study was obtained from the institutional ethics committee. Children with histologically proven thoracoabdominal neuroblastic tumors, who were examined by DW MRI with a b-value of 800s/mm2 were included in this study. Results: Twenty-one children with neuroblastic tumors were enrolled in the study. The mean ADC of the 13 neuroblastomas was significantly lower than that of 3 ganglioneuroma and 5 ganglioneuroblastoma (P£¼.001). For both b800 and ADC map images, there were statistically differences on visual evaluation (P£¼.01). Conclusion: DW imaging could reliably differentiate neuroblastoma from ganglioneuroma/ganglioneuroblastoma.

Hadrien A. Dyvorne¹, Guido H. Jajamovich¹, Niels Oesingmann², Thorsten Feiweier³, Ersin Bayram⁴, and Bachir Taouli^1
1Mount Sinai School of Medicine, New York, NY, United States, ²Siemens Medical Solutions USA, New York, NY, United States, ³Siemens AG, Erlangen, Germany, ⁴GE Healthcare, Waukesha, WI, United States

We describe a method to optimize b value sampling for intravoxel incoherent motion (IVIM) DWI acquisition in the liver and kidney, relying on data acquired in 56 subjects on two different platforms (1.5 and 3T). Combinatory subsets of b values (from 4 to 15) were subsampled from an initial 16 b values distribution. IVIM parameters were compared between the subsets and the initial 16 b values distribution, and subsets achieving lowest parameter deviations were retained. A 9 b values distribution was selected that offers significant reduction in scan time while still allowing the closest parameter estimation compared to 16 b value acquisition.

Jan Hansmann^1,2, Diego Hernando^3,4, and Scott B. Reeder^2,4
1Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Mannheim, BW, Germany, ²Radiology, University of Wisconsin, Madison, WI, United States, ³Radiology, University of Wisconsin-Madison, Madison, WI, United States, ⁴Medical Physics, University of Wisconsin, Madison, WI, United States

The observed decrease in ADC in patients with fatty liver is, at least in part, artifactual due to residual fat signal near the water peak.

Tetsuo Ogino¹, Toshiaki Miyati², Marc Van Cauteren³, Tomohiko Horie⁴, and Yutaka Imai^5
1Healthcare department, Philips Electronics Japan, LTD, Minato-ku, Tokyo, Japan, ²Kanazawa University, Kanazawa, Ishikawa, Japan, ³Philips Healthcare LTD, Minato-ku, Tokyo, Japan, ⁴Dept. of Radiology, Tokai University Hospital, Isehara, Kanagawa, Japan, ⁵Radiology, Tokai University, Isehara, Kanagawa, Japan

With conventional respiratory triggering DWI, left lobe of liver ADC is artificially elevated by cardiac motion and suffer from poor reproducibility. The combined method of PPU and respiratory navigator slice tracking on 3.0T scanner is proposed. The method eliminating the cardiac motion effect reduced left/right lobe normal parenchyma ADC difference times to 1.01 from 1.7 times of conventional respiratory triggering method. 20 slices were acquired 40-80 sec depending on subject. It allows uniform and reproducible ADC measurement in clinically feasible scan time.

Jeong Hee Yoon¹ and Jeong Min Lee^1
1Seoul National University Hospital, Seoul, Seoul, Korea

Dt provided better diagnostic performance than ADCtotal in differentiating benign from malignant lesions. Dp and f were significant parameters for diagnosing hypervascular FLLs.

Alexander D. Cohen¹, Moira F. Schieke², and Kathleen M. Schmainda^2
1Biophysics, Medical College of Wisconsin, Milwaukee, WI, United States, ²Radiology, Medical College of Wisconsin, Milwaukee, WI, United States

Diffusion weighted imaging (DWI) in the body poses problems not seen in the brain. The liver is sensitive to artifacts from breathing-induced motion. As a result, most body images are collected within a single breath hold or are respiratory-gated. In addition, DWI images can be acquired with different diffusion directions. In this study, a comprehensive analysis is performed to determine the optimal imaging parameters for DWI parameter repeatability. It was found that the coefficient of variation (CV) was lower for respiratory-gated compared to free breathing scans for IVIM metrics. ADC metrics were generally more repeatable than IVIM metrics.

Tetsuya Wakayama¹, Utaroh Motosugi², Shintaro Ichikawa², Hiroyuki Morisaka², and Hiroyuki Kabasawa^1
1Global Applied Science Laboratory, GE Healthcare, Hino, Tokyo, Japan, ²Radiology, University of Yamanashi, Chuo, Yamanashi, Japan

Synthesized diffusion weighted imaging (DWI) can provide the optimal diffusion weighting and would be helpful for clinical diagnosis in many regions. IVIM and the conventional ADC models were used to synthesize DWI of the liver and compared with DWI actually acquired. Both models could be used to synthesize DWI with high b-value range, however, the conventional ADC model resulted in overestimation of the signal in vessels in low b-value range. IVIM model can provide more accurate contrast than ADC model when synthesizing DWI with low b-value.

Utaroh Motosugi¹, Tetsuya Wakayama², Tomoaki Ichikawa¹, Tsutomu Araki¹, Suguru Kakite³, and Hadrien A. Dyvorne^3
1Radiology, University of Yamanashi, Japan, ²Advanced Application Center, GE Healthcare, Japan, ³Radiology, Mount Sinai School of Medicine, New York, United States

We compared the IVIM DWI results by five estimation methods using non-linear, linear regression, and Bayesian estimation.