Jürgen Machann¹, and Fritz Schick^1
1Section on Experimental Radiology, University Hospital Tübingen, Tübingen, Germany

¹H-MRS of the liver for quantification of hepatic lipid content has evolved to one of the most applied spectroscopic applications during the past years, as hepatic lipids are involved in metabolic diseases. However, as liver is a moving organ, spectral quality might be influenced by breathing and heartbeat. There is a discussion about the best acquisition strategy regarding different triggering modalities (ECG-triggering, respiratory triggering and combination of both). This study on 5 volunteers depicts differences in spectral quality and acquisition times for all combinations of triggering. Best results regarding quality and acquisition time are achieved when subjects breathe flatly during the TR interval and are in expiration during data acquisition.

Andreas Hock¹, Ladislav Valkovic², Ivan Frollo², Peter Boesiger¹, Anke Henning¹, and Spyros Kollias^3
1Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland, ²Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia, ³University Hospital of Zurich, Institute of Neuroradiology, Zurich, Switzerland

Navigator gated proton MR spectroscopy with inner volume saturation allows free breathing measurements of liver molecules while ensuring a precise location of the measured voxel. It is shown in 5 healthy volunteers that the spectral quality is improved and the variation of molecule ratios are decreased compared to measurements without gating. This technique may thus improve the quality of the diagnostic procedure of liver disease.

Erin Leigh MacMillan¹, Murielle Bortolotti², Andreas Boss¹, Chris Boesch¹, and Roland Kreis^1
1Dept. of Clinical Research, University of Bern, Bern, Bern, Switzerland, ²Dept. of Physiology, University of Lausanne, Lausanne, Switzerland

Metabolite cycled non-water-suppressed MRS enables automatic phase, frequency, and eddy-current correction of individually acquired spectra to improve SNR and lineshape of metabolite peaks. Examples from deliberate motion of the head and respiratory motion of the liver show remarkable improvement in both SNR and linewidth. The median FWHM of the liver spectra water peak was improved from 18Hz (range: 13-36Hz) to 15Hz (13-22Hz), demonstrating how this technique performs particularly well with decreasing quality of the originally measured spectra. The improved spectral quality will help make MRS more applicable in the clinic, especially in cases of subject or physiologic motion.

Giulio Gambarota¹, Mark Tanner¹, Marinette van der Graaf², Robert Mulkern³, and Rexford D Newbould^1
1Clinical Imaging Center, GSK, Imperial College, London, United Kingdom, ²Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands, ³Radiology, Children's Hospital Boston, Boston, United States

Fast measurement of both lipid and water T2 relaxation time is feasible in a single breath hold, with acquisition of several echoes and improved lipid SNR.

Jeong Min Lee¹, Eugene Joe¹, and Joon Koo Han^1
1Radiology, Seoul National University Hospital, Seoul, Seoul, Korea, Republic of

IDEAL can be used as a highly specific modality for the diagnosis of hepatic macrosteatosis as it does not have the confounding influence caused by hepatic iron deposition. IDEAL can accurately depict minimal macrovesicular hepatic steatosis within the normal range, thereby avoiding biopsy in potential living liver donors with an acceptable degree of steatosis for transplantation.

Gaspard d'Assignies^1,2, Ghislaine Fontés^3,4, Louis Gaboury⁵, Yvan Boulanger^4,6, Gilles Soulez⁷, Vincent Poitout^3,4, and An Tang^8
1Radiology, Hôpital Saint-Luc, Montreal, France, ²Beaujon Hospital, Université Paris VII, Canada, ³Montréal Diabetes Research Center, Canada, ⁴CRCHUM, Canada,⁵Department of anatomo-pathology, CHUM, Canada, ⁶Radiology, Hôpital Saint-Luc, Canada, ⁷Radiology, CRCHUM, Canada, ⁸Radiology, University of Montreal, Montreal, Quebec, Canada

The purpose of the study is to validate and optimize a routine 1.5T MRI method to detect and measure liver steatosis in an experimental glucolipotoxic rat model by using 1H-MR spectroscopy as the reference standard. Two 20° and 90° flip angle (FA) were applied on the dual echo in/out of phase sequence and T2* was calculated. MRI and 1H-MRS accurately distinguished steatotic from non steatotic liver. A significant correlation was found between dual-echo MRI and MRS. This correlation was higher with 90° (r = 0.749, P < 0.001) than with 20° FA (r = 0.651, P < 0.001). T2* correction did not improve the correlation with 1H-MRS.

Mina Kim¹, Queenie Chan^1,2, James YB Lau³, Sookja K Chung³, and Pek-Lan Khong^1
1Departement of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Pokfulam, Hong Kong, ²Philips Healthcare, Hong Kong, ³Department of Anatomy, The University of Hong Kong

Development of sensitive method to quantify glycogen in vivo may help to understand the pathophysiology of type-2 diabetes. In present study, we tested feasibility of in vivo glycogen detection in diabetic mouse model using chemical exchange saturation transfer imaging. Our results suggest that in vivo CEST quantification in mouse liver is feasible in a clinical scanner.

Edward Brian Welch^1,2, Johan Berglund³, Joel Kullberg³, Katie Colbert Coate⁴, Phil Williams⁴, Alan Cherrington⁴, and Malcolm J Avison^1,2
1Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ³Department of Radiology, Uppsala University, Uppsala, Sweden, ⁴Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, United States

Animal models in which whole body adiposity can be manipulated and the size of specific adipose tissue (AT) depots measured longitudinally and non-invasively, can help improve our understanding of the role of specific AT depots in the pathogenesis of obesity-associated metabolic diseases. In this abstract, we describe the adaptation of a whole body fat-water MR imaging acquisition and automated analysis pipeline, initially validated in human volunteers, for whole-body FWI in dogs. We demonstrate the utility of this pipeline by following the changes in lean and AT volume in dogs placed on an obesogenic high-fat, high-fructose diet known to increase insulin.

Edward Brian Welch^1,2, Malcolm J Avison^1,2, Kevin D Niswender³, Johan Berglund⁴, Joel Kullberg⁴, Lars Johansson⁴, Morten Bruvold⁵, and Heidi J Silver^3
1Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States, ²Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, United States, ³School of Medicine, Vanderbilt University, Nashville, TN, United States, ⁴Department of Radiology, Uppsala University, Uppsala, Sweden, ⁵MR Clinical Science, Philips Healthcare, Best, Netherlands

Whole-body MRI has great potential for quantifying the amount, type and distribution of adipose tissue to help better understand its metabolic consequences. Multi-gradient-echo MR acquisitions have been successfully used to quickly acquire whole-body fat-water imaging data sets. Dual energy x-ray absorptiometry (DEXA) is widely used in studies of body composition, but few direct comparisons of the performance of fat-water MR imaging (FWMRI) to DEXA are available, especially for 3T FWMRI. Here we present test-retest results of scanning 12 obese female subjects using a 3T mFFE whole-body FWMRI sequence as well as DEXA.

Julien Dinkel¹, Diana Wald², Heinz-Peter Schlemmer³, Hans-Peter Meinzer⁴, Rudolf Kaaks⁵, and Stefan Delorme^3
1Radiology, German Cancer Research Center, Heidelberg, Germany, ²Medical and Biological Informatics, German Cancer Research Center, ³Radiology, German Cancer Research Center, ⁴Medical and Biological Informatics, ⁵Cancer Epidemiology, German Cancer Research Center

The purpose of this study was to evaluate a semiautomatic method to quantify the distribution of visceral and non visceral internal fat acquired using the two point Dixon technique from whole-body MRI data. We performed MR imaging on 30 subjects using a 1.5T system using a 3d-Dixon-VIBE sequence. Signal strength changes within the 3D volume due to variation in coil sensitivity were corrected with a normalization algorithm. Full automated correction of the Dixon-mismatch artifacts were performed successfully. Automated segmentation quantifying the distribution of visceral and non visceral fat were done and assessed as successful by an experienced radiologist.

Ankur Poddar¹, and Rama Jayasundar^1
1NMR, All India Institute of Medical Sciences, New Delhi, Delhi, India

Correlation of lipid profile and insulin sensitivity with body fat evaluated using MRI, Dual Energy X-ray Absorptiometry and Bioimpedance A.Poddar 1, R. Jayasundar 2, A.C. Ammini 3, A. K. Mukhopadhyaya 4 Departments of Biotechnology1, NMR2, Endocrinology3, Lab Medicine4, All India Institute of Medical Sciences, New Delhi, India. In this study, body fat assessed using MRI, Dual energy x-ray absorptiometry (DEXA) and Bio-impedance analysis (BIA) methods are correlated individually with biochemical parameters such as lipid profile, insulin sensitivity, BMI & BMR and compared. These biochemical parameters are considered risk factors for diabetes, obesity, etc. The data indicates that fat mass evaluated using all the three techniques (MRI, DEXA and BIA) correlated well with insulin sensitivity and BMI and can be used interchangeably. However, only MRI evaluated fat mass correlated well with cholesterol and MRI had the additional advantage of giving information on fat distribution in the whole body.

Tania Buehler¹, Andreas Boss¹, Roland Kreis¹, and Chris Boesch^1
1Dept. of Clinical Research, University of Bern, Bern, Switzerland

The metabolic syndrome, which includes insulin resistance (IR), is a risk factor for cardiovascular diseases with epidemic dimensions. It is hypothesized that impaired mitochondrial activity could be a cause of IR. ATP synthesis exchange rates determined by ³¹P MRS allow a non-invasive estimation of mitochondrial activity. Several human studies exist for skeletal muscle, but only one for liver. Two methods (³¹P saturation (ST) and inversion transfer (IT)) have been implemented in combination with volume selection based on saturation bands. In this study the two methods for a determination of ATP synthesis exchange rates are compared in skeletal muscle and liver.

Gavin Hamilton¹, Michael S Middleton¹, Takeshi Yokoo¹, and Claude B Sirlin^1
1Department of Radiology, University of California, San Diego, San Diego, California, United States

The multi-peak structure of the fat ¹H MR Spectrum allows non-invasive estimation of triglyceride composition in adipose tissue in vivo. The study compares variability in triglyceride composition of three different abdominal adipose tissue depots. We see statistically different triglyceride compositions in the three abdominal adipose tissue depots.

Jimin Ren¹, Manisha Shah², Maram Museitif², Lynne Roetzer², A Dean Sherry^1,3, Craig R Malloy^1,2, and Devasmita Choudhury^2
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, United States, ²VA North Texas Health Care System, ³Department of Chemistry, University of Texas at Dallas, Richardson, Texas

Chronic kidney disease (CKD) and type 2 diabetes (T2D) are both highly prevalent and complex disorders. While T2D may cause CKD; CKD also independently causes insulin resistance. Increased intramyocellular lipids (IMCL) have been associated with insulin resistance and diabetes but the role of the compartmental distribution of lipids in normal physiology and disease is still debated. This study was designed to test the hypothesis that patients with T2D and CKD have higher levels of IMCL compared to patients with CKD but without overt T2D. Surprisingly, the results showed that IMCL was not significantly different in diabetic vs. nondiabetic CKD patients.

Patrick Antkowiak¹, Brian Stevens², Marcia McDuffie², and Frederick H Epstein^3
1Biomedical Engineering, University of Virginia, Charlottesville, Virginia, United States, ²Microbiology, University of Virginia, ³Radiology, University of Virginia

Pancreatic β cells secrete insulin and maintain blood glucose homeostasis; in type 1 diabetes mellitus (T1D), β cell function and mass decline, with potentially severe complications. Noninvasive imaging to detect this decline would be important for both pre-clinical and clinical studies. We used Look-Locker MRI to measure the pancreatic relaxation rate R1 after injection of MnCl2, which labels functional β cells, and applied this to a mouse model of T1D characterized by a graded loss of functional β cell mass. We measured a decline in pancreatic R1 concurrent with the incidence of T1D and decline in functional β cell mass.

Hank C.W. Donker¹, Nils A. Krämer¹, Jens Otto², Ioana Slabu³, Martin Baumann³, Uwe Klinge², and Christiane K. Kuhl^1
1Department of Diagnostic Radiology, RWTH Aachen University, Aachen, NRW, Germany, ²Department of Chirurgy, RWTH Aachen University, Aachen, NRW, Germany,³Helmholtz Institute for Applied Medical Engineering, RWTH Aachen University, Aachen, NRW, Germany

Surgical textile mesh implants for abdominal hernia repair are hard to delineate in MRI. To improve MR-visualization, superparamagnetic iron oxides (SPIO) were implanted in the mesh polymer base material. SPIO generate magnetic susceptibility gradients. To discriminate SPIO induced voids from proton-free structures positive contrast susceptibility imaging was developed. Here 4 ways to generate positive contrast from susceptibility gradients were compared: IRON, FLAPS, white-marker imaging and SGM. The acquisition of a gradient echo image with a calculated Short Term Fourier Transform Susceptibility Gradient Map image is to be preferred for positive contrast imaging of SPIO loaded hernia meshes.

Daisuke Suzuki^1,2, Masayuki Yamaguchi¹, Toshihiro Furuta^1,3, Kohki Yoshikawa², and Hirofumi Fujii^1
1Functional Imaging Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan, ²Graduate Division of Health Sciences, Komazawa University, Setagaya, Tokyo, Japan, ³Department of Radiology, The Tokyo University Hospital, Tokyo, Japan

Since the presence of sentinel lymph nodes (SLNs) metastasis predicts a poor prognosis, the diagnosis of SLN metastasis is clinically important. MR lymphography by means of the interstitial administration of superparamagnetic iron oxide (SPIO) is one of the techniques that can sensitively detect SLNs based on the signal reduction by SPIO trapped by macrophages. To our knowledge, the intra-lymph node distribution of subcutaneously administered SPIO has not been fully understood. In this study, we demonstrated the inhomogeneous distribution of interstitially administered SPIO within regional lymph nodes of mice using high-resolution MRI and Prussian blue-stained specimens

Steven Sourbron¹, Wieland Sommer², Christoph J Zech², Maximilian F Reiser², and Karin A Herrmann^2
1Division of Medical Physics, University of Leeds, Leeds, United Kingdom, ²Department of Clinical Radiology, University of Munich, Munich, Germany

The choice of arterial and venous delay times in DCE-MRI of the liver has a strong effect on the measured parameters. In this study a number of alternative methods are applied to patient data and compared. Results show that an arterial delay time is necessary to obtain a good fit to the data, but including an additional venous delay causes unstable and overestimated perfusion values. It is concluded that DCE-MRI data in the liver are best analysed by fitting an arterial delay, and assuming that the venous delay is zero.

Manil Chouhan¹, Shonit Punwani¹, Alan Bainbridge², Nathan Davies³, Raj Mookerjee³, Rajiv Jalan³, and Stuart Taylor^1
1Centre for Medical Imaging, University College London, London, London, United Kingdom, ²Department of Medical Physics, University College London Hospitals NHS Trust,³Institute of Hepatology, University College London

Feasibility of DCE-MRI for liver haemodynamic assessment before and after modulation of portal venous flow is demonstrated, with presentation of preliminary data.

Alan De Lun Xu¹, Anja C Brau², Yuji Iwadate², Jarrett Rosenberg¹, Shreyas Vasanawala¹, and Robert Herfkens^1
1Radiology, Stanford University, Stanford, CA, United States, ²GE Healthcare

Conventional contrast-enhanced 3D T1w hepatic imaging requires serial breath-hold acquisitions to capture the contrast dynamics, inherently limiting spatial resolution and image quality. The hepatobiliary-specific contrast agent Gd-EOB-DTPA offers a prolonged time window of contrast-enhancement over which data can be acquired. This work evaluates the clinical feasibility of using a navigator-gated 3D T1w sequence to improve the spatial resolution and image quality of Gd-EOB-DTPA-enhanced hepatobiliary imaging compared to conventional breath-hold imaging.

Tomohiro Nakayama¹, Akihiro Nishie¹, Takashi Yoshiura¹, Yoshiki Asayama¹, Kousei Ishigami¹, Daisuke Kakihara¹, Yukihisa Takayama¹, Makoto Obara², and Hiroshi Honda^1
1Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Fukuoka, Japan, ²Philips Electronics Japan

In this study, a balanced steady-state free precession (SSFP) sequence with motion-sensitized driven-equilibrium (MSDE) preparation was used as an alternative technique for magnetic resonance cholangiopancreatography (MRCP).�@�@T2-weighted MRCP was associated with poor visualization of the biliary systems due to excreted Gd-EOB-DTPA, as previously reported. Use of MSDE-balanced MRCP resulted in higher CNR and better visualization of biliary structures than T2-weighted MRCP. Moreover, problematic vessel�fs signals, such as PV and HV, were sufficiently suppressed by MSDE technique.�@�@In conclusion, we demonstrated the usefulness of MSDE-balanced MRCP sequenced in Gd-EOB-DTPA post-contrast study.

Christine Iseman¹, Bachir Taouli¹, Rajan T Gupta², John Leyendecker³, and Elmar Merkle^2
1Mount Sinai School of Medicine, New York, NY, United States, ²Duke University, Durham, NC, United States, ³Wake Forest University, Winston-Salem, NC, United States

In this study, we report preliminary results from a US multicentric study, comparing qualitatively and quantitatively Gd-EOB-DTPA and Gd-BOPTA for diagnosis of FNH. 23 FNHs were assessed in 11 preliminary patients. Lesion conspicuity was equivalent for both contrast agents at all phases. Quantitative enhancement was significantly higher at the arterial and portal venous phases for Gd-BOPTA, and higher at the hepatobiliary phase for Gd-EOB-DTPA. These preliminary results indicate advantage for BOPTA at the dynamic phase, and advantage for EOB at the hepatobiliary phase.

Mikael Fredrik Forsgren^1,2, Olof Dahlqvist Leinhard^1,3, Gunnar Cedersund^2,4, Nils Dahlström^1,3, Örjan Smedby^1,3, Torkel B Brismar⁵, and Peter Lundberg^3,6
1Department of Medical and Health Sciences, Division of Radiological Sciences, Linköping University, Linköping, Sweden, ²Department of Clinical and Experimental Medicine, Diabetes and Integrated Systems Biology, Linköping University, Linköping, Sweden, ³Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden, ⁴School of Life Sciences, Freiburg Institute of Advanced Sciences, Freiburg, Germany, ⁵Department of Radiology, Karolinska University Hospital, Stockholm, Sweden, ⁶Department of Radiation Physics, CKOC, University Hospital of Linköping, Linköping, Sweden

Clinical dynamic contrast-enhanced MRI examinations of the human liver can be analyzed in detail using tissue models. Our aim was to devise the first physiologically correct minimal model that describes the most important routes of contrast agent flux. Based on established pharmacokinetic equations incorporated into a system of ordinary differential equations, the model has a significant potential for gaining a better understanding of the contrast agent behaviour in the human body. We believe that it is possible, in a Bayesian modeling framework, to use the model on individual patient data, thereby increasing the information obtained from clinical examinations.

Scott D Swanson¹, Jeremy Adler², Phyllissa Schmiedlin-Ren³, Kinan Rahal³, Laura Reingold³, and Ellen M Zimmermann^3
1Department of Radiology, University of Michigan, Ann Arbor, MI, United States, ²Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, United States, ³Department of Internal Medicine-Gastroenterology, University of Michigan, Ann Arbor, MI, United States

synopsis

Tom Dresselaers¹, Christine Breynaert², Gert Van Assche², and Uwe Himmelreich^1
1Biomedical NMR Unit/ MoSAIC, K.U.Leuven, Leuven, Brabant, Belgium, ²Division of Gastroenterology, K.U.Leuven, leuven, Brabant, Belgium

In human colon disease, the value of MRI and CT enterography as a non-invasive assessment tool of transmural inflammation and extraluminal complications is increasingly recognized. However, data on MR imaging as a screening tool to study murine ileitis or colitis are limited. In this study the feasibility of using T2-weighted imaging and T2 maps to distinguishing between a DSS induced acute and chronic murine colitis model was evaluated. T2 values are markedly different between the control, acute and chronic group. This is confirmed by histology which shows more fibrosis in the chronic versus acute model.

Owen John Arthurs¹, Martin John Graves¹, Ilse Joubert¹, and David John Lomas^1
1Radiology, University of Cambridge, Cambridge, Cambridgeshire, United Kingdom

The optimal contrast medium for neonatal gut MR imaging is unclear. Here, we investigate the relative T1 properties of several different potential agents to provide optimal signal. We then tested a variable IR pulse during interactive SSFSE imaging to null existing bowel fluid and demonstrate feasibility. An optimal in-vitro TI of 500 - 800ms gave maximal signal difference between pineapple juices and milk, but in-vivo this was 1000 ms. Application of an optimally timed IR pulse can allow for improved contrast medium imaging in this sensitive population.

Bradley Spieler¹, Nicole Hindman¹, Caludia Reuben Seuss¹, Alec J Megibow¹, Joseph Levy², Kerry Zabriskie², Daniel Sahlein¹, Rafael Rivera¹, and Sooah Kim^1
1Radiology, New York University, New York, NY, United States, ²Pediatric Gastroenterology, New York University, New York, NY, United States

MR imaging of the pediatric abdomen can be challenging, often secondary to inability to tolerate long scan times. Twenty five pediatric patients (mean age 11.2 years) with Crohn’s disease referred for MR enterography at 1.5 T were evaluated. Two radiologists reviewed post contrast images of MRI during the first session and all images including pre- and post contrast sequences during the second session. The intestine was divided into 10 segments. The readers evaluated the presence or absence of disease in regard to the presence of active inflammation using a five-point grading system. Sensitivity, specificity, PPV, NPV, and accuracy for diagnosing definite active inflammation using post contrast images alone were 83.3%, 86.9%, 89.3%, 80%, and 84.9%, respectively. In all five of the false negative cases there was a disagreement in at least one bowel segment with respect to the presence or absence of abscess and/or sinus tracts which was confirmed on non-contrast images (HASTE without fat suppression).

Jelena Curcic¹, Matthias Sauter², Werner Schwizer², Peter Boesiger¹, and Andreas Steingoetter^1,2
1Institute for Biomedical Engineering, University and ETH, Zurich, Zurich, Switzerland, ²Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland

Gastric emptying, distention, intragastric secretion and mixing are important factors in pathogenesis of gastro-intestinal (GI) diseases such as gastro-esophageal reflux disease (GERD). A formerly described method, for simultaneous T1 mapping and imaging was optimized and validated for free breathing gastric imaging. The optimized sequence (GOLD) was used in-vivo to simultaneously detect intragastric secretion and mixing as well as gastric emptying during free breathing. This pilot study shows the feasibility of the GOLD sequence to detect multiple gastric parameters in one single free breathing period of maximally 2 min and emerges as a versatile tool for diagnostic GI MRI.

Freddy Odille¹, Alex Menys², Asia Ahmed², Shonit Punwani², Stuart Taylor², and David Atkinson^1
1Centre for Medical Image Computing, University College London, London, United Kingdom, ²Centre for Medical Imaging, University College London, London, United Kingdom

Small bowel motility assessment by dynamic MRI is of increasing interest for the clinical management of enteric disorders such as Crohn’s disease. A postprocessing technique is described for the automated assessment of bowel motility. The technique jointly registers 2D dynamic images (nonrigidly) and models local intensity changes due to through-plane motion or flow. Validation was performed by drawing various small bowel regions in 10 patients with known or suspected Crohn’s disease. We assessed the performance of the registration (manual versus automatically propagated markers) as well as the agreement between automated motility measures with expert grading of the motility.

Elisa Placidi¹, Luca Marciani², Caroline L Hoad¹, Klara C Garsed², Susan E Pritchard¹, Eleanor F Cox¹, Carolyn Costigan³, Robin C Spiller², and Penny A Gowland^1
1SPMMRC, University of Nottingham, Nottingham, United Kingdom, ²Nottingham Digestive Diseases Centre Biomedical Research Unit, Nottingham, United Kingdom, ³Brain and Body Centre, University of Nottingham, Nottingham, United Kingdom

MRI was used to investigate the mode of action of anti-diarrheal drugs, loperamide and loperamide + simethicone, using a model of acute diarrhoea based on a mannitol drink. 18 healthy volunteers were imaged on a 1.5 T Philips Achieva scanner with several sequences up to 5 hours after the mannitol drink, to assess changes in the gut in terms of water content, volume, T2 and image signal intensity. Differences between the three conditions have been quantified, proving that the MRI technique optimised is efficient to investigate the response of the gut to drugs.

Lau Brix^1,2, Steffen Ringgaard², Brian Stausbøl-Grøn², Bodil Ginnerup Pedersen², Yasmina Berber³, Mario Ries³, and Thomas Sangild Sørensen^4,5
1Department of Clinical Engineering, Aarhus N, Region Midt, Denmark, ²MR-Centre, Aarhus University Hospital, Skejby, Aarhus N, Region Midt, Denmark, ³Laboratoire IMF, Centre National de la Recherche Scientifique/Universite Bordeaux 2, France, ⁴Department of Computer Science, Aarhus University, Denmark, ⁵Institute of Clinical Medicine, Aarhus University, Denmark

The aim of this project was to implement a real-time data and reconstruction system for imaging of the bowel by using a constant azimuthal profile based on the Golden Ratio. The reconstruction gave the operator a unique possibility to interactively reconstruct images with an optimal compromise between a true temporal resolution and a sliding window reconstruction in real-time. This study demonstrates that real-time images of the bowel may improve the diagnosis and documentation of patients with Crohn’s disease, bowel stenosis or altered bowel motility and is a step toward using MRI for imaging moving organs on-line in real-time.

Harald E. Möller^1,2, Zackary I. Cleveland², Laurence W. Hedlund², John Nouls², Matthew Freeman^2,3, Yi Qi², and Bastiaan Driehuys^2
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, ²Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, ³Graduate Program in Medical Physics, Duke University, Durham, NC, United States

Information on pulmonary perfusion can be obtained by from experiments involving intravenous injection of hyperpolarized (HP) ¹²⁹Xe. Signal curves recorded in rats during bolus transport through the gas-exchange region can be fitted to a model that assumes delayed bolus arrival and an exponential transport function to account for dispersion effects. Quantitative results are consistent with expected values for the cardiac output and transit times in the lung.

Yulin V Chang^1
1Mechanical Engineering, Washington University, St. Louis, MO, United States

We present in this a work a simple model of gas exchange in the lung for hyperpolarized Xe129. This model expresses the two dissolved-xenon signal amplitudes in the lung in terms of several important pulmonary parameters, including surface area-to-volume ratio, air-blood barrier thickness, capillary blood transit time, etc. It provides a means to quantify not only the microstructure, but the physiology and function of the lung. It can potentially be used in diagnosing a variety of related pulmonary diseases.

Chengbo Wang¹, John P Mugler, III^1,2, Eduard E de Lange¹, and Talissa A Altes^1
1Radiology, University of Virginia, Charlottesville, VA, United States, ²Biomedical Engineering, University of Virginia, Charlottesville, VA, United States

Global long-time-scale helium-3 ADC values as a function of diffusion time were measured in 29 healthy volunteers and 14 subjects with COPD. The percentage difference in group mean ADC versus diffusion time had a well-defined maximum at a diffusion time of approximately 1 s, suggesting that this diffusion time affords the best ability to discriminate COPD and healthy subjects. Furthermore, the percentage difference between the two groups at the long-time scale (110%-150%) was much greater than that found at the short-time-scale (commonly, 20%-100%), which supports the premise that long-time-scale diffusion is more sensitive to COPD than short-time-scale diffusion.

Torsten Dorniok¹, Peter Magnusson¹, Frederik Hengstenberg^1,2, Sergei Karpuk³, Jorgen Vestbo², Per Åkeson¹, and Lise Vejby Søgaard^1
1Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark, ²Department of Cardiology and Respiratory Medicine, Copenhagen University Hospital, Hvidovre, Denmark, ³Institute of Physics, University of Mainz, Mainz, Germany

A non-linear image registration method was used to co-register hyperpolarized 3He diffusion MRI data acquired at different stages of inflation. The method was validated using synthetic data and data from healthy volunteers. ADC values in the original and registered maps were compared regionally to assess if the transformation had any considerable effect on the values.

Jionghan Dai¹, Eric T Peterson², James H Holmes³, Robert V Cadman¹, Ronald L Sorkness⁴, and Sean B Fain^1,5
1Medical Physics, University of Wisconsin - Madison, Madison, Wisconsin, United States, ²Biomedical Engineering, University of Wisconsin - Madison, Madison, Wisconsin, United States, ³Global Applied Science Laboratory, GE Healthcare, Madison, Wisconsin, United States, ⁴pharmacy, University of Wisconsin - Madison, Madison, Wisconsin, United States, ⁵Radiology, University of Wisconsin - Madison, Madison, Wisconsin, United States

Noble gas MRI enables high contrast to noise dynamic imaging during respiratory maneuvers. A model of gas in-flow using linear system theory to deconvolve the dispersion at the trachea provides maps that are analogous to gas flow, while washout delay during forced exhalation provides maps of gas trapping. In this work the feasibility of these modeling approaches is evaluated in adults and children with known obstructive lung disease.

Ahmed Fathi Halaweish^1,2, Youbing Yin³, Daniel R. Thedens¹, Ching-Long Lin³, Edwin JR vanBeek⁴, and Eric A Hoffman^1,2
1Department of Radiology, University of Iowa, Iowa City, IA, United States, ²Department of Biomedical Engineering, University of Iowa, Iowa City, IA, United States,³Department of Mechanical & Industrial Engineering, University of Iowa, Iowa City, IA, United States, ⁴Queen's Medical Research Institute, University of Edinburgh, Edinburgh, Scotland

Hyperpolarized ³Helium MRI has enabled probing of ventilation distribution (static ventilation) and the underlying microstructure (apparent diffusion coefficients). We have successfully evaluated these techniques against regional ventilation measures based on local air volume changes, obtained from matching FRC to TLC MDCT scans. A strong positive correlation between the techniques was observed, as well as a strong fit of the regression line between the two, when assessed on a whole or left & right lung basis. Differences arise as a function of gas density, such that ³Helium distributions are higher in the ventral portions when compared against the MDCT estimates.

Andrew Wheatley¹, Usaf Aladl¹, Igor Gyacskov¹, Aaron Fenster^1,2, and Grace Parraga^1,2
1Imaging, Robarts Research Institute, London, Ontario, Canada, ²Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada

Until the emergence of hyperpolarized 3He MRI, it has been difficult to quantify and visualize the structure/function relationships of the lung with high spatial and temporal resolution. Our objective was to generate, from static ventilation 3He MRI images of COPD, three-dimensional volumetric lung models that incorporate k-means clustering of differential pixel intensities across the lung that represent partial, fully and non-ventilated regions. We developed software and a visualization environment to generate a set of fully rotational 3D surfaces of the regional ventilation patterns for individual COPD subjects and an image-based lung atlas that combines the functional features of 55 COPD subjects.

Salma Ajraoui¹, Steven Parnell¹, Juan Parra-Robles¹, Robert Ireland¹, and Jim Wild^1
1University of Sheffield, Sheffield, United Kingdom

Compressed Sening reconstruction of lung 3He images is improved through the introduction of prior knowldge. Here coregistered 1H MRI image and the knowledge of the hyperpolarised gas depolarisation through the k-space filter are used for a more accurate reconstruction at higher reduction factor.

Yoshiharu Ohno^1,2, Hisanobu Koyama¹, Takeshi Yoshikawa¹, Nobukazu Aoyama², Daisuke Takenaka¹, Keiko Matsumoto³, Masaya Takahashi⁴, Makoto Obara⁵, Marc van Cauteren⁵, and Kazuro Sugimura^1
1Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan, ²Radiology, Kobe University Hospital, Kobe, Hyogo, Japan, ³Radiology, Yamanashi Hospital of Social Insurance, Kofu, Yamanashi, Japan, ⁴Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Houston, TX, United States, ⁵Philips Healthcare, Tokyo, Japan

Recently, several investigators have tried to determine the utility of regional T2* measurement in the lung for assessment of pulmonary diseases in animal studies. We hypothesized that direct T2* measurement in the lung at 3.0 T MR system has a potential role to play as a method for pulmonary functional loss assessment and clinical stage classification as well as thin-section MDCT. The purpose of this study was to determine the capability of pulmonary MR imaging with ultra-short TEs (UTEs) in a 3.0 T system for pulmonary functional assessment and clinical stage classification in smokers.

Kang Wang¹, Frank Korosec^1,2, Mark Schiebler², Christopher Francois², Scott Reeder^2,3, Thomas Grist², Reed Busse⁴, James Holmes⁴, Jean Brittain⁴, Nathan Artz¹, Sean Fain^1,3, and Scott Nagle^2
1Medical Physics, University of Wisconsin-Madison, Madison, WI, United States, ²Radiology, University of Wisconsin-Madison, Madison, WI, United States, ³Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, United States, ⁴Applied Science Lab, GE Healthcare, Madison, WI, United States

MR pulmonary perfusion is well suited for studying the pulmonary circulation and understanding the physiology and pathology of the lung. However, MR pulmonary perfusion has been challenging due to the requirements for large spatial coverage, high temporal resolution, and high spatial resolution. The purpose of this study is to demonstrate the feasibility of obtaining high isotropic spatial resolution 3D dynamic pulmonary perfusion images of the whole chest with very high temporal resolution. The technique combines a previously developed Interleaved Variable Density sampling method with parallel imaging and Cartesian HYPR reconstruction.

Piotr A Wielopolski¹, Pierluigi Ciet^2,3, Rashindra Manniesing⁴, Sandra Lever², Martin Lequin¹, Gabriel Krestin¹, and Harm A.W.M. Tiddens^1,2
1Radiology, Erasmus Medical Center, Rotterdam, Netherlands, ²Pulmonology, Erasmus Medical Center, Sophia Children Hospital, Rotterdam, Netherlands, ³Radiology, Department of Medical-Diagnostic Sciences and Therapies, University of Padua, Padua, Italy, ⁴Department of Informatics and Radiology, Erasmus Medical Center, Rotterdam, Netherlands

Tracheomalacia is an excessive narrowing of the intra-thoracic part of the trachea such that the airway is softer and more susceptible to collapse. We demonstrate a suitable acquisition scenario using static and dynamic 3D MRI sequences with sufficient temporal and spatial resolution to provide good morphological information and visualization of dynamic events in the central airways. We evaluate a segmentation and dynamic analysis tool to compute the cross-sectional areas of the central airways down to the 2nd generation branching and detect airway narrowing during the respiratory manouvers. We conclude that cine-MRI is a feasible non-invasive radiation free alternative for bronchoscopy.

Smitha Rajaram¹, Andy James Swift^1,2, David Capener¹, Robin Condliffe³, Charlie Elliot³, Judith Hurdman³, Christine Davies⁴, Catherine Hill⁴, David G Kiely³, and Jim M Wild^1
1Academic unit of Radiology, University of Sheffield, Sheffield, yorkshire, United Kingdom, ²NIHR Cardiovascular Biomedical Research Unit, Sheffield, United Kingdom,³Pulmonary Vascular Disease Unit, Royal Hallamshire Hospital, Sheffield, ⁴Department of Radiology, Royal Hallamshire Hospital, Sheffield

Interstitial lung disease is characterised by inflammation and scarring of the pulmonary interstitium leading to increased signal from the diseased lung tissue. The purpose of our study was to compare 1.5 SSFP MRI of the lung parenchyma with high resolution computed tomography (HRCT), which is considered as the ‘gold standard’ imaging modality in assessment of patients with interstitial lung disease. MR lung imaging has good specificity and sensitivity for diagnosing pulmonary fibrosis. However our results show that lung MRI has a poor sensitivity (78.5%) for identifying mild degree of pulmonary fibrosis but high sensitivity for severe disease.

Kiarash Emami¹, Hooman Hamedani¹, Yinan Xu¹, Stephen J. Kadlecek¹, Yi Xin¹, Puttisarn Mongkolwisetwara¹, Harrila Profka², Masaru Ishii³, and Rahim R. Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States,³Otolaryngology–Head & Neck Surgery, Johns Hopkins University, Baltimore, MD, United States

The accelerated acquisition scheme for imaging specific ventilation effectively reduced the total imaging time by a factor of two as implemented in mechanically ventilated Yorkshire pigs. In addition to retaining the breathing pattern closer to normal conditions, this technique is less sensitive to the accumulative RF effect, as well as O2-induced depolarization of 3He, which collectively improve the accuracy of r measurements, and encourages transition to voluntarily breathing human subjects.

Maurizio F. Cereda¹, Kiarash Emami², Stephen J. Kadlecek², Yi Xin², Puttisarn Mongkolwisetwara², Harilla Profka², Amy Barulic², Stephen Pickup², Nicholas N. Kuzma², Masaru Ishii³, Hooman Hamedani², Benjamin M Pullinger², Rajat Ghosh², Jennia Rajaei², Clifford S. Deutschman¹, and Rahim R. Rizi^2
1Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ²Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States, ³Otolaryngology–Head & Neck Surgery, Johns Hopkins University, Baltimore, Maryland, United States

Positive end expiratory pressure (PEEP) protects surfactant deficient lungs from lung injury during mechanical ventilation. The mechanisms of this effect have not been established at the alveolar level. We used hyperpolarized gas MRI to quantify the effects of PEEP on lung microstructure on the alveolar and distal airspace level in surfactant deficient lungs. We show that, in spite of the increase in inspiratory pressures, PEEP alleviates airspace overdistension caused by surfactant deficiency. This technique can provide unique pathophysiological insight in the mechanisms of ventilator-associated lung injury.

Ronn P Walvick^1,2, Austin L Reno², Mathew J Gounis², and Mitchell S. Albert^2
1Radiology, New York University Langone Medical Center, New York, NY, United States, ²Radiology, University of Massachusetts Medical School, Worcester, MA, United States

Synopsis: In this work, we present data on the application of the measurement of measuring the time course of the partial pressure of oxygen in the lungs using hyperpolarized helium to detect ischemia in a novel rodent model of pulmonary ischemia. We show that both the initial partial pressure of oxygen is higher, and oxygen uptake rate in the ischemic lung is lower, in the ischemic then in the contralateral lung of embolized animals, and in both lungs of control animals. This work may be useful for the non-invasive evaluation of experimental treatment options for pulmonary embolism. 

Maxim Terekhov¹, Manuela Gueldner², Klaus Gast³, Julien Rivoire¹, Ursula Wolf³, Janet Friedrich¹, Sergei Karpuk², Zahir Salhi², and Laura Maria Schreiber^1
1Department of Diagnostic and Interventional Radiology. Section of Medical Physics, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany, ²Institute of Physics, Johannes Gutenberg University Mainz, ³Department of Diagnostic and Interventional Radiology, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany

Dynamic ventilation (DV) of lung measured with 3He MRI is an efficient tool to visualize the intrapulmonary gas inflow. In current work we performed comparison 3He application with two different form of gas bolus: short bolus delivered by Application Unit (AU) in Free-Breathing mode and Forced Inspiration from Tedlar bag (TB) via fine tube with high resistance and prolonged bolus shape. The discrepancy between application modes was considered in terms of first orders Linear Transfer Function. The results show that TB-application changes significantly the gas transport in parenchyma and higher order derivations of “input bolus function” should be accounted.