Marta Tibiletti¹, Martin Tschechne¹, Andrea Bianchi², Detlef Stiller², and Volker Rasche^1,3
1Core Facility Small Animal MRI, Ulm University, Ulm, Germany, ²Target Discovery Research, In-vivo imaging laboratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany,³Department of Internal Medicine II, Ulm University, Ulm, Germany

Functional information of the lung is of great importance for staging and monitoring lung disease. Imaging of lung ventilation has been addressed by inhalation of polarized gases like Helium or Xenon. Major limitation of this technique rises from the high costs of equipment and gases. As an efficient alternative to polarized gases, the use of fluorinated gases has been proposed. In pre-clinical application these have always been used in combination with intubation, which does not realistically reflect the ventilation during free breathing. In this contribution the imaging of ventilation in mice with fluorinated gases during free-breathing is addressed.

Andreas Voskrebenzev^1,2, Marcel Gutberlet^1,2, Frank Wacker^1,2, and Jens Vogel-Claussen^1,2
1Institute of Diagnostic and Interventional Radiology, Hanover, Germany, ²German Centre for Lung Research, Hanover, Germany

Fourier Decomposition (FD) is a lung function imaging technique with a high clinical potential. Nevertheless the 2D acquisition leads to long acquisition times for complete lung scans and the 3D breathing motion might lead to errors in the ventilation measurements. Self-navigated sequences offer the possibility to reconstruct images in different respiratory states. Using a stack-of-stars sequence, a method for 3D fractional ventilation (FV) imaging is demonstrated for six healthy volunteers and compared with FV calculated by 2D FD. The two methods show a good agreement. Additionally, 3D FV depicts 3D lung motion, which is not adequately detected with 2D FD.

Yutaka Natsuaki¹, Xiaoming Bi¹, Gerhard Laub¹, and David Grodzki^2
1Siemens Healthcare, Los Angeles, CA, United States, ²Siemens Healthcare, Erlangen, Germany

With recent developments in ultra-short TE (UTE) MRI sequences such as PETRA with the respiratory triggering and the segmented acquisition, MRI has shown a potential of being a viable radiation-free alternative to the incumbent gold standard CT lung imaging.  Within a volunteer validation study (n=14), the current work demonstrates a recent progress in the PETRA lung MRI towards its robustness and its applicability to all patient populations. The proposed solution improves patient comfort and image contrast by suppressing the unintended high intensity signals from surrounding tissues.

Nora Kassner¹, Meike Weis², Katrin Zahn³, Thomas Schaible⁴, Stefan O Schoenberg², Lothar R Schad¹, K Wolfgang Neff², and Frank G Zöllner^1
1Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany, ²Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany, ³Department of Pediatric Surgery, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany, ⁴Department of Neonatology, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany

Reported measured lung perfusion data of 2-year old children after congenital diaphragmatic hernia repair was evaluated by regions of interest (ROI) within the acquired 3D volume. In this work a histogram based approach is used to characterize the distribution of perfusion in the whole left and right lung, and suitable quantities to characterize the distribution are extracted.

 

Orso Pusterla^1,2, Grzegorz Bauman^1,2, and Oliver Bieri^1,2
1Radiological Physics, Dep. of Radiology, University of Basel Hospital, Basel, Switzerland, ²Department of Biomedical Engineering, University of Basel, Basel, Switzerland

In contrast to the common view that Gd-based contrast agents have only marginal/limited effect on balanced steady state free precession (bSSFP) from its $$$T_2/T_1$$$ signal properties, we will demonstrate that especially for lung imaging single-dose contrast agent administration increases the parenchymal signal nearly up two fold.

Orso Pusterla^1,2, Grzegorz Bauman^1,2, Mark Wielpütz^3,4, Claus Heussel^3,4, and Oliver Bieri^1,2
1Radiological Physics, Dep. of Radiology, University of Basel Hospital, Basel, Switzerland, ²Department of Biomedical Engineering, University of Basel, Basel, Switzerland, ³Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at University Hospital Heidelberg, Heidelberg, Germany, ⁴Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany

Monitoring lung ventilation is of great interest to assess pulmonary function and disease progression. Here, a novel, fast, and simple three-dimensional (3D) quantitative in vivo ¹H imaging method is introduced, reflecting regional ventilation information. To this end, typically five ultra-fast balanced steady state free precession (ufSSFP) scans are repetitively performed in breath-hold from which a respiratory index map, $$${\gamma}$$$, is derived. The new measure $$${\gamma}$$$ shows high reproducibility in healthy volunteers and high sensitivity to respiratory defects, such as in patients with COPD.

Li Feng¹, Jean Delacoste², Hersh Chandarana¹, Davide Piccini^2,3, Francis Girvin¹, Matthias Stuber^2,4, Daniel K Sodickson¹, and Ricardo Otazo^1
1Center for Advanced Imaging Innovation and Research (CAI2R), New York University School of Medicine, New York, NY, United States, ²University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland, ³Advanced Clinical Imaging Technology, Siemens Healthcare, Lausanne, Switzerland, ⁴Center for Biomedical Imaging (CIBM), Lausanne, Switzerland

A four-dimensional (4D) respiratory motion-resolved UTE MRI method is presented for free-breathing lung MRI with isotropic spatial resolution. Center-out radial half-projection k-space data are continuously acquired using a 3D golden-angle UTE sequence. The radial k-space data are retrospectively sorted into distinct respiratory states, resulting in an undersampled 4D dataset (k_x-k_y-k_z-respiration) using a respiratory motion signal extracted from the acquired data. The undersampled 4D data are reconstructed by exploiting sparsity along the new respiratory dimension. The proposed approach enables free-breathing lung MRI with 100% scan efficiency, allowing for assessment of lung tissue in arbitrary orientations at different respiratory states.

Simon Veldhoen¹, Andreas Max Weng¹, Clemens Wirth¹, Andreas Steven Kunz¹, Janine Nicole Knapp¹, Daniel Stäb^1,2, Florian Segerer³, Helge Uwe Hebestreit³, Thorsten Alexander Bley¹, and Herbert Köstler^1
1Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany, ²The Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia,³Department of Pediatrics, University Hospital Würzburg, Würzburg, Germany

Fourier Decomposition MRI using the SENCEFUL approach is a recent development in functional lung MRI allowing for site-resolved assessment of lung function. The purpose of the present study is to evaluate its feasibility for ventilation imaging in patients with cystic fibrosis. Seven cystic fibrosis patients and 7 healthy volunteers were examined, lung ventilation maps were reconstructed and quantitative ventilation measurements were performed in tidal and deep breathing. Mean quantitative ventilation was significantly lower for patients with cystic fibrosis when compared to the healthy controls. The ventilation maps indicated increased ventilation inhomogeneity in cystic fibrosis patients.

Daniel Alamidi¹, Amir Smailagic², Abdel Bidar², Nicole Parker², Marita Olsson², Sonya Jacksson², Linda Swedin², Paul Hockings^3,4, Kerstin Lagerstrand¹, and Lars E Olsson^5
1Department of Radiation Physics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden, ²AstraZeneca R&D, Mölndal, Sweden, ³Medtech West, Chalmers University of Technology, Gothenburg, Sweden, ⁴Antaros Medical, BioVenture Hub, Mölndal, Sweden, ⁵Department of Medical Physics, Lund University, Translational Sciences, Malmö, Sweden

Tobacco smoking is the main cause of COPD. MRI may improve the characterization of COPD where lung T1 mapping has been used to study lung disease. We investigated whether tobacco smoke exposure affects lung T1 in a mouse model with repeated T1 readouts and biological measurements. Free breathing 3D-UTE T1 maps of the lungs were weekly performed over one month in mice exposed to air or tobacco smoke. The lung T1 was shortened in the tobacco smoke exposed mice, most likely due to early signs of smoking-induced lung pathology. Consequently, T1 is a potential biomarker of lung disease.

Marta Tibiletti¹, Andrea Bianchi², Åsmund Kjørstad³, Detlef Stiller², and Volker Rasche^1,4
1Core Facility Small Animal MRI, Ulm University, Ulm, Germany, ²Target Discovery Research, In-vivo imaging laboratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany,³Department of Neuroradiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany, ⁴Department of Internal Medicine II, Ulm University, Ulm, Germany

1D (k-space center) and 3D (sliding window 3D reconstruction) have been evaluated for respiratory retrospective self-gating for Quasi Random UTE-3D lung acquisition in freely breathing rats. Low-resolution 3D GRASP reconstruction allowed the extraction of an effective gating signal from changes in lung-liver interface position. The 1D center-of-k-space method did not yield sufficient gating signal fidelity, most likely caused by the only limited changes of the anatomy in the investigated volume, and to a lesser extent intensity modulations introduced by residual eddy-currents.

Iliyana P Atanasova¹, Pauline Desogere¹, Clemens K Probst², Nicholas Rotile¹, Andrew M Tager², and Peter Caravan^1
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, ²Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Boston, MA, United States

Idiopathic pulmonary fibrosis is a fatal condition without effective treatment. Given evidence that vascular leak promotes fibrosis, we assessed whether pulmonary leak could be quantified using dynamic MRI and an intravascular tracer. In a mouse model we observed that permeability to albumin rose sharply on day 3 after insult, returned to baseline by day 5 and increased moderately between days 5-13. To our knowledge this is the first report of the time course of vascular leak in pulmonary fibrosis. The proposed method could be useful for studying the role of lung permeability in fibrosis and for monitoring of treatment response.

Ulrich Katscher¹ and Peter Börnert^1
1Philips Research Europe, Hamburg, Germany

Reliable MR imaging of lung tissue could be an important element of diagnosing lung-related diseases. The very short T2 components of lung tissue, one of the main problems of lung imaging, can be visualized using ultrashort echo times (UTE). Furthermore, UTE sequences allow the determination of conductivity of the imaged tissue. This study shows the principle feasibility of UTE to image lung conductivity, examining healthy volunteers. Obtained conductivity was lower for inspiration breath hold than expiration breath hold, which is the expected behaviour due to corresponding fraction of air (with nearly zero conductivity) inside lungs during inspiration and expiration.

Grzegorz Bauman^1,2, Sylvia Nyilas^2,3,4, Orso Pusterla^1,2, Christoph M Heyer⁵, Cordula Koerner-Rettberg⁶, Philipp Latzin^3,4, and Oliver Bieri^1,2
1Division of Radiological Physics, Deparment of Radiology, University Hospital of Basel, Basel, Switzerland, ²Department of Biomedical Engineering, University of Basel, Basel, Switzerland, ³Department of Pediatric Pneumology, University Children's Hospital Basel (UKBB), Basel, Switzerland, ⁴Division of Respiratory Medicine, Department of Pediatrics, University Children's Hospital of Bern, Bern, Switzerland, ⁵Institute of Diagnostic Radiology, Interventional Radiology and Nuclear Medicine, Ruhr-University of Bochum, Bochum, Germany, ⁶Department of Pediatric Pneumology, University Children's Hospital of Ruhr University Bochum at St Josef-Hospital, Bochum, Germany

In this work, the feasibility of contrast-media-free pulmonary Fourier decomposition (FD) MRI is assessed in patients with primary ciliary dyskinesia (PCD). An automatic evaluation of regional functional defects on fractional ventilation and perfusion FD maps has been developed. Furthermore, the lung function evaluated using FD MRI is compared to the parameters obtained using multiple breath washout technique and spirometry. Statistical analysis was used to find significant correlations between FD MRI and lung function techniques.

Ho-Fung Chan¹, Neil J. Stewart¹, Juan Parra-Robles¹, Guilhem J. Collier¹, and Jim M. Wild^1
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom

Compressed sensing (CS) was implemented to reduce scan time and facilitate acquisition of 3D multiple b-value ³He diffusion-weighted (DW) MRI data for whole lung morphometry. A fully-sampled 3D DW-MRI dataset was retrospectively undersampled using CS simulations to determine optimal k-space undersampling patterns. Whole lung morphometry measurements derived from prospective 3-fold undersampled 3D multiple b-value DW-MRI were compared to 3D and 2D fully-sampled equivalents. Good agreement was obtained between lung morphometry measurements indicating 3D multiple b-value ³He DW-MRI with CS can provide reliable measurements of whole lung morphometry within a single breath-hold. 

Felix C Horn ¹ and Jim M Wild^1
1University of Sheffield, Sheffield, United Kingdom

Single breath washout (SBW) is a whole lung pulmonary function test that has been shown to be sensitive to early changes in lung disease. Of particular clinical interest has been the Phase III slope (S_III) as the concentration decay between 25-75% of the exhaled volume.

In this work rapid lung imaging of exhaled hyperpolarized gas is used to acquire 2D images of SBW of subjects expiring to residual lung volume. The ability to calculate regional S_III  from those time resolved images is demonstrated in healthy volunteers.

Juan FPJ Abascal^1,2, Manuel Desco^1,2,3, and Juan Parra-Robles^1,2
1Department of Bioengeering and Aerospace Engineering, Universidad Carlos III de Madrid, Madrid, Spain, ²Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain, ³Centro de Investigación en Red de Salud Mental (CIBERSAM), Madrid, Spain

Diffusion MRI measurements using hyperpolarized gases are generally acquired during patient breath hold, which yields a compromise between achievable image resolution, lung coverage and number of b-values. In this work, we propose a novel method that incorporates the knowledge of the signal decay into the reconstruction (SIDER) to accelerate the acquisition of MR diffusion data by undersampling in both spatial and b-value dimensions. SIDER is assessed by restrospectively undersampling diffusion datasets of normal volunteers and COPD patients. Results suggest that accelerations of at least x7 are achievable with negligible effect in the estimates of diffusion parameters.

Ho-Fung Chan¹, Neil J. Stewart¹, Guilhem J. Collier¹, and Jim M. Wild^1
1Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom

Whole-lung coverage ³He ventilation images, maps of ADC, alveolar dimension (Lm_D), and T₂* were acquired in a single breath-hold using a multiple-interleaved 3D sequence with compressing sensing (CS). A fully-sampled three-interleaved ADC and T₂* dataset was acquired for CS simulations, to determine the optimal k-space undersampling patterns. A prospective, 3-fold undersampled 3D five-interleaved dataset was acquired with CS and parametric maps were compared to those calculated from fully-sampled datasets. CS-derived ADC and Lm_D values showed good agreement with fully-sampled equivalents. CS-derived T₂­* values were lower than fully-sampled ones due to the smoothing process of the CS reconstruction.

Scott H. Robertson^1,2, Elianna A. Bier^1,2, Rohan S. Virgincar^1,3, and Bastiaan Driehuys^1,2,3,4
1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, ²Medical Physics Graduate Program, Duke University, Durham, NC, United States, ³Department of Biomedical Engineering, Duke University, Durham, NC, United States, ⁴Department of Radiology, Duke University Medical Center, Durham, NC, United States

Hyperpolarized ¹²⁹Xe experiences chemical shifts between the lung airspaces, interstitium, and capillary beds, enabling functional information to be directly probed. However, in order to realize the potential of these chemical shifts, the spectrum must be carefully decomposed. Previous methods have assumed only two dissolved-phase resonances exist in the human lung and have used inconsistent 0 ppm reference frequencies. Here we present novel non-linear fitting of complex exponentially decaying FIDs and demonstrate that the dissolved phase signal can be robustly decomposed into three dissolved-phase resonances. We present updated frequencies and widths using and appropriately adjusted 0 ppm reference value.

Scott H. Robertson^1,2, Jennifer Wang¹, Geoffry Schrank¹, Holman P. McAdams³, and Bastiaan Driehuys^1,2,4,5
1Center for In Vivo Microscopy, Duke University Medical Center, Durham, NC, United States, ²Medical Physics Graduate Program, Duke University, Durham, NC, United States, ³Department of Radiology, Duke University Medical Center, Durham, NC, United Kingdom, ⁴Department of Biomedical Engineering, Duke University, Durham, NC, United States, ⁵Department of Radiology, Duke University Medical Center, Durham, NC, United States

While gas-exchange imaging with ¹²⁹Xe holds great potential for enhancing both the diagnosis and followup of IPF, the quantitative ability of these techniques is currently  limited by the SNR and spatial resolution afforded by the limited dissolved-phase signal and highly undersampled acquisition. Here we tune our reconstruction for these challenging conditions, and demonstrate improvements in image quality. We then quantify the loss of gas exchange in the apex and base of the lung and show that there is significantly reduced gas exchange in the basal regions of subjects with IPF relative to healthy controls.

Hooman Hamedani^1,2, Yi Xin¹, Stephen J Kadlecek¹, Heather Gatens¹, Maurizio Cereda³, Sarmad M Siddiqui^1,2, Mehrdad Pourfathi^1,4, Joseph Naji¹, Masaru Ishii⁵, and Rahim R Rizi^1
1Radiology, University of Pennsylvania, Philadelphia, PA, United States, ²Bioengineering, University of Pennsylvania, Philadelphia, PA, United States, ³Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA, United States, ⁴Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, United States, ⁵Johns Hopkins University, Baltimore, MD, United States

Aside from the superior diagnostic power that HP gas MRI provides through imaging unique aspects of lung function, it is evident that the underlying mechanisms that lead to subsequently evident global changes in the lung function in future are detectable through regional and functional imaging using HP gas MRI.

Laura L Walkup¹, Robert P Thomen^1,2, Teckla Akinyi^1,3, Wolfgang Loew⁴, Kai Ruppert¹, John P Clancy⁵, Zackary I Cleveland¹, and Jason C Woods^1
1Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, ²Department of Physics, Washington University in St. Louis, St. Louis, MO, United States, ³Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH, United States, ⁴Imaging Research Center, Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States, ⁵Division of Pulmonary Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States

We demonstrate hyperpolarized ¹²⁹Xe MRI in healthy pediatric control subjects and cystic fibrosis patients as young as age 7, for the first time.  Subjects experienced a transient nadir in SpO₂ that quickly returns to baseline with normal breathing.  Despite having similarly high lung function (i.e., normal FEV₁), CF patients had nearly 4-fold increase in ¹²⁹Xe ventilation defect volume compared to their healthy peers, with statistical significance.  Importantly, ventilation defects were present even in CF patients with FEV₁ near or exceeding 100% predicted, suggesting that ¹²⁹Xe MRI is more sensitive to early CF lung disease than traditional clinical spirometry.

Wei Tang¹, Yao Huang¹, Ning Wu¹, Wenwen Lu¹, Linlin Qi¹, and Bing Wu^2
1Diagnostic Radiology, Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China, People's Republic of, ²GE heathcare MR research China, Beijing, China, People's Republic of

Magnetic resonance (MR) elastography depitcs the elastic properties of tissues of interest has been primarily applied in the work-up of diagnosis for hepatic fibrosis. Theoretically, interference fringes could be visualized on the elastogram due to the miscalculation of the interaction between the attenuated propagations of shear wave and the tissue overlying or surrounding to the investigated subject, which might be one of the main concern that limited the clinical potentials of MRE. We propose an investigation on the feasibility of MR elastography in characterizing the mechanical properties of anterior mediastinal masses with the consideration of the relatively superficial location of these entities, therefore few interactions between the shear wave and subject unexpected were produced during the process of elasticity mapping. It was demonstrated in our study that anterior mediastinal mass in various etiology of thymic carcinoma, thymoma, and lymphoma has distinct elastic properties. MR elastography was helpful in distinguishing the thymic carcinoma from lymphoma.

Therese Sjoholm¹, Benjamin A Thomas¹, Yin Mo², Louisa Sun², Ashley St. John³, Paul Anantharajah Tambyah², and John J Totman^1
1A*STAR-NUS Clinical Imaging Research Centre, Singapore, Singapore, ²Department of Medicine, National University Hospital Singapore, Singapore, Singapore, ³Duke-NUS Graduate Medical School, Singapore, Singapore

In this study we assess the feasibility of using MRI for measurement of pleural effusion in Dengue Fever. 30 subjects with confirmed Dengue infection were scanned using T2-weighted HASTE MRI and chest x-rays (CXRs) at baseline and 4-8 days follow-up. Fluid accumulation in the pleural cavity was assessed for both modalities. For MRI, significantly different fluid accumulations were measured between baseline and follow-up (p=0.002). The fluid accumulations were all below the detectability limit of CXR. As such, MRI provides a sensitive measurement of pleural effusion in dengue fever and can be used to track fluid accumulation over time.

Lorenzo A Orci¹, Graziano Oldani¹, Stephanie Lacotte¹, Florence Slits¹, Iris Friedli², Wolfgang Wirth³, Jean-Paul Vallée², Christian Toso¹, and Lindsey Alexandra Crowe^2
1Division of Abdominal and Transplantation Surgery, Hepato-pancreato-biliary Centre, Department of Surgery, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland, ²Division of Radiology, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland, ³Institute of Anatomy, Paracelsus Medical University, Salzburg, Austria

In vivo liver cancer research commonly uses rodent models of liver tumor growth. One of the limitations of such models is the lack of accurate and reproducible endpoints for dynamic assessment tumor nodules.  We used 3T clinical MRI to quantify tumor volume over time and correlate to gold standard histological volumes and blood levels of α-fetoprotein in two rat orthotopic models of hepatocellular carcinoma (HCC). Combination of 3D isotropic gradient echo for accurate volume and T2 for contrast provided appealing correlation. We have developed a 3D volume quantification method that enables follow-up and analysis of complex tumor morphology.

Jeong Hee Yoon¹, Jeong Min Lee¹, Robert Grimm², Son Yohan³, Kiefer Berthold², Tobias Kai Block⁴, Hearsh Chandarana⁴, and Joon Koo Han^1
1Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, ²Siemens Healthcare, Erlangen, Germany, ³Siemens Healthcare Korea, Seoul, Korea, Republic of, ⁴Radiology, NYU School of medicine, New York, NY, United States

Acquisition of optimal late arterial phase is essential for focal liver lesion diagnosis and detection at gadoxetic acid-enhanced liver magnetic resonance imaging (MRI). However, it is often challenging to obtain late arterial phase due to short arterial window and frequent involuntary motion during arterial phase. We attempted to characterize the frequency, onset, and duration of the involuntary motion after gadoxetic acid injection and whether acceptable quality of late arterial phase can be obtained using incoherent undersampling technique.

Ke Wang¹ and Xiaoying Wang^2
1Radiology, Peking University First Hospital, Beijing, China, People's Republic of, ²Beijing, China, People's Republic of

This study was to compare the category of unenhanced combined contrast enhanced MR imaging (MR) and Multiphasic CT (CT) in the diagnosis of HCC based on LI-RADS 2014 in patients with cirrhosis induced by HBV infection. We restropectively collected patients who had both undergone CT and MR imaging within 30 days and had pathologically proved HCC. A radiologist using LI-RADS 2014 recored the imaging features and the category of all the lesions. The result showed that MR showed higher LI-RADS category compared with CT, and had better ability for the showing of some imaging features. Thus,  we concluded that MRI can elevate the LI-RADS category and is recommended in the initial evaluation of suspected HCC priority to CT.

Li Yang¹, Ying Ding², Mengsu Zeng³, Shengxiang Rao³, and Ruofan Sheng^3
1Shanghai Institute of Medical Imging, Zhongshan Hospital of Fudan University, Shanghai, China, People's Republic of, ²Zhongshan Hospital of Fudan University,Shanghai Institute of Medical Imging, Shanghai, China, People's Republic of, ³Zhongshan Hospital of Fudan University, Shanghai, China, People's Republic of

Hepatobiliary-phase gadoxetic acid-enhanced MR imaging may reflect liver function and was reported to be able to predict liver fibrosis stage with higher reliability. Aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 (FIB-4) are widely used non-invasive tests that estimate liver fibrosis. We compared the diagnostic performance of T1 mapping on Gd-EOB-DTPA-enhanced 1.5T magnetic resonance imaging (MRI), APRI  and  FIB-4  for evaluating the severity of liver fibrosis in 118 patients with chronic viral hepatitis B, and the results showed The HBP T1 relaxation time measurement on gadoxetic acid-enhanced appears superior to unenhanced, D% (the reduction rate) of T1 relaxation times, the APRI and FIB-4 index in differentiating advanced liver fibrosis.

Qian Ji¹, Zhi-Qiang Chu², Tao Ren¹, Pan-Li Zuo³, Thorsten Feiweier⁴, Andre de Oliveira⁴, and Wen Shen^1
1Radiology, Tianjin First Central Hospital, Tianjin, China, People's Republic of, ²Transplantation, Tianjin First Central Hospital, Tianjin, China, People's Republic of, ³MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, People's Republic of, ⁴Siemens Healthcare GmbH, Erlangen, Germany

Hepatic warm ischemia-reperfusion injury (WIRI) is clinically relevant in liver transplantation. We undertook this study to determine the feasibility of using IVIM, DTI, and BOLD MR imaging for the characterization of hepatic WIRI. 20 hepatic WIRI models and control rabbits were examined using a 3T clinical MR scanner, which followed by biochemical and histopathological analysis. There were significant differences of Dfast, Dslow, PF, ADC, and R2* values between the two groups. There were significant correlations between MR parameters and biochemical parameters. This indicated that multiparametric functional MR imaging are noninvasive and valuable techniques for assessing the pathophysiologic changes of hepatic WIRI.

Yuan Le^1
1Radiology and Imaging Science, Indiana University School of Medicine, Indianapolis, IN, United States

This paper is to discuss the impact of fat on the Gd-based contrast behavior in a mixture of water based Gd-BOPTA solution and fat. A set of vials, contains such mixtures with various fat fraction and Gd-BOPTA concentration, was constructed and scanned using both Turbo Spin Echo (TSE) with 3 point Dixon, and VIBE-Dixon. With VIBE-Dixon, the slopes of the regression (relaxivity) of R1 vs. [Gd] in water were very close among groups with various fat fraction; while with TSE image, the slopes of R1 vs. [Gd] in whole mixture were close among vial groups.

Chang-Hee Lee¹ and Cheol Min Park^2
1Radiology, Korea University Guro Hospital, Seoul, Korea, Republic of, ²Korea University Guro Hospital, Seoul, Korea, Republic of

The short breath-hold high-resolution MR technique showes better HAP image quality with less degraded HAP and lower incidences of breath-hold difficulty and gadoxetic acid related dyspnea than the conventional long breath-hold MR technique.

Nikhar Kinger¹, Sadhna Nandwana¹, Courtney Moreno¹, Kelly Cox¹, and Pardeep Mittal^1
1Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, United States

The liver is an important oncologic organ. Primary liver tumors can arise from a variety of different liver components such as hepatocytes, bile duct epithelium, neuroendocrine cells, and mesenchymal cells. We will discuss imaging and histopathological features of primary liver tumors and their common and uncommon mimics.

shuangshuang xie¹, qing li¹, yu zhang², wenjing hou¹, yue cheng¹, and wen shen^1
1Radiology, Tianjin First Center Hospital, Tianjin, China, People's Republic of, ²Philips healthcare, Beijing, China, People's Republic of

 

This study evaluated the potential of T1rho for liver fibrosis evaluation and to explore the best TSL points with good B0 and B1 inhomogeneity. Thirteen healthy control subjects and eight patients with clinically diagnosed liver fibrosis were scanned 3D b-TEF sequence. T1rho map were constructed by using 7-TSLs, 6-TSLs or 3-TSLs and compared between groups. Our results showed both 7-TSLs and 6-TSLs had moderate diagnostic efficacy, and AUC of 7-TSLs was slightly higher than 6-TSLs. We conclude 7-TSLs and 6-TSLs are recommended for the diagnosis of liver fibrosis, and 7-TSLs has slightly higher diagnostic performance.

Petros Martirosian¹, Rolf Pohmann², Christina Schraml³, Holger Schmidt³, Nina F Schwenzer³, Martin Schwartz¹, Klaus Scheffler², Konstantin Nikolaou³, and Fritz Schick^1
1Section on Experimental Radiology, University of Tübingen, Tübingen, Germany, ²Max Planck Institute for Biological Cybernetics, Tübingen, Germany, ³Department of Diagnostic and Interventional Radiology, University Hospital of Tübingen, Tübingen, Germany

The separation of portal-venous and hepatic arterial blood supply is important for the evaluation of chronic liver diseases and the characterization of liver lesions. The aim of this study was to investigate the capability of a pseudo-continuous arterial spin labeling sequence, to separate arterial and portal venous perfusion of the liver using a background suppression technique and different tagging plane orientations. It was demonstrated that the presented method provides high quality perfusion images of the liver without application of intravenous contrast agent and offers promising approaches for the separation of arterial and portal-venous perfusion fractions.

Yang Feng¹, He Wang¹, and Junbo Li^1
1Philips Healthcare, shanghai, China, People's Republic of

The shape and position of liver is varied through respiratory movement in DCE MR liver images. A robust 3D deformable registration was employed to define the distortion between them and compensate it. As a result, the liver and vessels will be located at the exact position with the exact shape (include vessels) of the reference image after registration. 

Jing Zhang¹, Yikai Xu¹, Yihao Guo², Yanqiu Feng², Queenie Chen³, Yingjie Mei^2,4, Xiangliang Tan¹, Jiajun Zhang¹, Xixi Zhao¹, Zeyu Zheng¹, and Chunhong Wang^1
1Department of Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou, China, People's Republic of, ²School of Biomedical Engineering and Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, China, People's Republic of, ³Philips Healthcare, Hong Kong, China, People's Republic of, ⁴Philips Healthcare, Guangzhou, China, People's Republic of

The quantitative evaluation of hepatic function is important for monitoring patients and preoperative assessment of the hepatic reserve. This work aims to assess the sensitivity of IVIM in evaluating liver function in patients with chronic liver disease. The results demonstrate that perfusion-related parameters (D* and f) are useful for indicating the severity of liver disease, and may have the potential to become a promising non-invasive tool for monitoring liver function.

Shih-Han Hung¹, Meng-Chieh Liao¹, Cheng-Ping Chien¹, Wen-Chau Wu², and Hsiao-Wen Chung^3
1Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan, ²Graduate Institute of Oncology, National Taiwan University, Taipei, Taiwan, ³Electrical Engineering, National Taiwan University, Taipei, Taiwan

A new scheme was proposed to analyze intravoxel ihcoherent motion MR imaging data of the liver. The method integrated the combined use of single- and bi-exponential signal decaying models to deal with regions with absence of prominent vasculature, and the removal of data obtained at b-values less than 15s/mm² to avoid contamination from large vessels. Results from ten healthy subjects scanned twice at 3T showed substantially improved reproducibility in the pseudo-diffusion coefficient D*, while those of the true diffusion coefficient and the profusion fraction were unaltered. Using our scheme the estimated D* mostly fall within 38 to 85x10^-3 mm²/s.

Zhaoxia Yang¹, Xinxing Hu¹, Heyue Liang¹, Robert Grimm², Caixia Fu³, Xu Yan⁴, Hui Liu⁴, Mengsu Zeng¹, and Shengxiang Rao^1
1Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai, China, People's Republic of, ²MR Application Predevelopment, Siemens Healthcare, Erlangen, Germany, ³Application department, Siemens Shenzhen Magnetic Resonance Ltd., Shenzhen, China, People's Republic of, ⁴MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of

Histogram analysis of whole-liver ADC maps was applied for patients with liver fibrosis to assess its diagnostic value and correlation with fibrosis stages achieved from liver biopsy. Our study shows that the mean and the 75th percentile ADC were significantly lower with the increasing grade of liver fibrosis. The median, standard deviation (SD), 5th, 10th, 25th, 90th and 95th percentiles also showed statistical differences among pathological fibrosis grades. In conclusion, histogram analysis of whole-liver ADC maps has a potential value for quantifying liver fibrosis grades.

Takashi Iwanaga¹, Yoshihiko Fukukura², Tomonori Saito¹, Masashi Sasaki¹, Yuichi Kumagae², Koji Takumi², Takuro Fujisaki¹, and Takashi Yoshiura^2
1Department of Radiological Technology, Kagoshima University Hospital, Kagoshima, Japan, ²Department of Radiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan

When liver MRI is performed using Gd-EOB-DTPA, DWI is often obtained after Gd-EOB-DTPA injection to shorten examination time in the busy clinical practice. We compared malignant tumor conspicuity on low b-value DWI after contrast between chemical shift selective (CHESS) and short inversion time inversion recovery (STIR) sequences. Malignant liver tumors were more conspicuous with STIR than with CHESS. DWI with STIR is useful for visualizing malignant liver tumors after Gd-EOB-DTPA injection, thus decreasing overall scan time.

Yusuke Inoue¹, Gou Ogasawara¹, Keiji Matsunaga¹, Kaoru Fujii¹, Hirofumi Hata², and Yuki Takato^2
1Kitasato University School of Medicine, Sagamihara, Japan, ²Kitasato University Hospital, Sagamihara, Japan

We evaluated two commercially available methods for non-uniformity correction, an image-based method (SCIC) and a calibration-based method (PURE), in Gd-EOB-DTPA-enhanced MR imaging using a 3T scanner. SCIC improved uniformity for the precontrast images; however, artificial hyperintensity in the liver surface was evident especially in the hepatobiliary-phase images. Quantitative evaluation of contrast effects were severely distorted by SCIC. PURE improved uniformity in the precontrast and hepatobiliary-phase images, and appeared to aid quantitative evaluation of the signal intensity after contrast administration. PURE is indicated to be a useful non-uniformity correction method in Gd-EOB-DTPA-enhanced MR imaging using a 3T scanner.

qing li¹, shuangshuang xie¹, yu zhang², wenjing hou¹, yue cheng¹, and wen shen^1
1Radiology, Tianjin First Center Hospital, Tianjin, China, People's Republic of, ²Philips healthcare, Beijing, China, People's Republic of

This study investigated the value of multi-parametric analysis using MR IVIM, BOLD MRI and DKI for the diagnosis of liver fibrosis. Eight patients with clinically diagnosed liver fibrosis and thirteen healthy control subjects were scanned with DKI, IVIM, BOLD. IVIM derived D*, D, f, DKI derived MD, K value and BOLD derived R2* were compared between the two groups. Our results showed D*, D, f, MD decreased, R2* and K value increased in patients with liver fibrosis, but only D* and D demonstrated significant difference (P<0.05). We therefore conclude D* and D could be useful in the diagnosis of liver fibrosis.

Takashige Yoshida^1,2, Yuki Furukawa¹, Hiroaki Tsuchiya¹, Kohei Yuda¹, Masami Yoneyama³, Nobuo Kawauchi¹, and Haruo Saito^4
1radiology, Tokyo metropolitan police hospital, Tokyo, Japan, ²Graduate school of Medicine, Tohoku university, Miyagi, Japan, ³Marketing, Philips Electronics Japan, Tokyo, Japan, ⁴Division of Diagnostic Image Analysis, Graduate school of Medicine, Tohoku University, Miyagi, Japan

A extend of slice direction and high resolution imaging cannot help to increase scan time in hepatic MRI. The hepatic MRI is necessary to hold their breath, and breath holding influenced on image quality. Hence improved image quality on hepatic MRI is a required free breath sequence. Our study using 3D stack-of-stars trajectory with respiratory navigator is objective that perfectly eliminate respiratory motion effect. A sequence combined motion averaging by stack-of-stars and correction by navigator is possible to eliminate respiratory motion.

Yasuhiro Fujiwara¹, Hirotoshi Maruyama², Nobuyuki Kosaka³, Yoshiyuki Ishimori⁴, and Noriyuki Furukawa^2
1Department of Medical Imaging, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan, ²Radiological Center, National Hospital Organization Kumamoto Medical Center, Kumamoto, Japan,³Department of Radiology, University of Fukui, Fukui, Japan, ⁴Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences, Ibaraki, Japan

We applied 3D phase-sensitive inversion recovery (PSIR) sequence to liver MR imaging. Experiments with phantom and healthy subjects revealed that this sequence improved contrast enhancements of Gd-based agents and liver-to-spleen or muscle contrasts while simultaneously providing an accurate T1 map of the liver. Better Gd contrast enhancements and liver contrasts may improve tumor-to-liver contrasts in the hepato-biliary phase with Gd-based hepatocyte-specific contrast agents, and the accurate T1 map may be useful for liver-function assessments. Although a clinical study is required to evaluate its utility, this sequence may have potential to improve liver MR imaging. 
 

Pippa Storey¹ and Dmitry S. Novikov^1
1Radiology Department, New York University School of Medicine, New York, NY, United States

T2* measurements in the abdomen are often corrupted by macroscopic magnetic susceptibility effects from air in the lung and bowel. We show that sensitivity to linear B0 variations can be eliminated by tailoring the 2D slice profile appropriately and truncating the echo train where the phase difference between adjacent voxels within or across slices exceeds $$$\pi/2$$$. This improves T2* accuracy without the need for post hoc corrections. When compared with a conventional approach, the proposed technique demonstrates reduced sensitivity to B0 inhomogeneity in the liver caused by magnetic susceptibility differences in the lung.

Zhuo Shi¹, Xinming Zhao¹, Ouyang Han¹, and Lizhi Xie^2
1Department Of Imaging Diagnosis,Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing China, Beijing, China, People's Republic of, ²GE Healthcare, MR Research China, Beijing, Beijing, China, People's Republic of

By comparing the breath-hold, respiratory-triggered, and free-breathing techniques in diffusion-weighted magnetic resonance imaging (MRI) for the evaluation of focal liver lesions on a 3.0T system, we found that:  The free-breathing DWI is better than others for the patients who want to do the whole liver examination; but for the patients with focal liver lesions who need to do the DWI scan to evaluate the local lesions, the breath-hold DWI was optimal. Generally speaking, the respiratory-triggered DWI of the 3T MRI system had higher SNR and CNR in any case, and it was the best DWI acquisition technique.

Ijin Joo¹, Jeong Min Lee¹, Dong Ho Lee¹, Su Joa Ahn¹, Eun Sun Lee², and Joon Koo Han^1
1Radiology, Seoul National University Hospital, Seoul, Korea, Republic of, ²Radiology, Chung-Ang University Hospital, Seoul, Korea, Republic of

The latest Liver Imaging Reporting And Data System (LI-RADS v2014) incorporates gadoxetic acid-enhanced MRI into the diagnostic algorithm of hepatocellular carcinoma (HCC). In this study, we investigated the effects of ancillary features of gadoxetic acid-enhanced MRI in the determination of LI-RADS categories of HCCs. On gadoxetic acid-enhanced MRI, LI-RADS showed sensitivities of 69.0% and 67.8% in the diagnosis of HCCs (LR-5/5v) in two reviewers, respectively. Ancillary features of HCCs on gadoxetic acid-enhanced MRI including hepatobiliary imaging features frequently resulted in upgrade LR-3 to LR-4. 

Qungang Shan¹, Tianhui Zhang¹, Yong Zhang², Yunhong Shu³, Zhuang Kang¹, Bingjun He¹, Jingbiao Chen¹, Zhenyu Zhou², and Jin Wang^1
1Department of Radiology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China, People's Republic of, ²GE Healthcare China, Beijing, China, People's Republic of, ³Mayo Clinic, Rochester, MN, United States

Among the various causes of hepatocellular carcinoma (HCC), hepatitis B virus (HBV) infection is the most common one in Asian countries including China. We assessed the correlation of ADC and IVIM parameters with the histological differentiation of HBV-related HCCs. Our results showed that ADC, D and f coefficients are significantly correlated with histological differentiation of HBV-related HCC. According to ROC analysis, ADC, D and f were useful parameters for the evaluation of histological differentiation of HCCs. ADC showed better diagnostic performance compared with D and f IVIM is a promising tool for predicting histological differentiation of HBV-related HCC.

Lifang Wu^1
1Fudan University, Shanghai, China, People's Republic of

More and more studies have been attributed to the evaluation of IVIM analysis for disease characterization or response assessment, but its measurement reproducibility when applied in clinical practice and research still be in controversial. There is only few prior research on repeatability of IVIM-derived parameters of hepatocellular carcinoma (HCC) as well as the choice of free-breathing (FB). In this study we used our own data to explore the reproducibility of IVIM-derived parameters, ADC_(0,500) and ADC_total of HCC.

Kartik Jhaveri¹, Vijay Chidambaram², James Brierley¹, Bernard Cummings^1,3, Rajesh Bhayana¹, Ravi Menezes¹, Erin Kennedy⁴, and Richard Kirsch^4
1UHN,university of Toronto, Toronto, ON, Canada, ²Royal Liverpool Hospital, Liverpool, United Kingdom, ³Toronto, Canada, ⁴Mt.Sinai Hospital,University of Toronto, Toronto, Canada

Rectal cancer patients treated with preoperative chemoradiation therapy with complete treatment response can be considered for individualised therapies such as ‘wait and watch’ avoiding surgery. However this currently can only be definitely identified by postoperative histopathology. Diffusion weighted-MRI has been well correlated to tumor biology and treatment response. Volumetric ADC histogram analysis eliminates errors resulting from tumor heterogeneity and variable diffusivities by including the tumor volume and could provide promise for prediction of treatment response and clinical outcomes,thereby providing means for individualised therapy.

Zhengyang Zhou¹, Jian He¹, Song Liu¹, and Weibo Chen^2
1Department of Radiology, Drum Tower Hospital, School of Medicine, Nanjing University, Nanjing, China, People's Republic of, ²Philips Healthcare Greater China, Shanghai, China, People's Republic of

Forty-five patients with gastric cancer underwent DWI prior to surgery to evaluate whether ADC value correlates with the HER2 status. HER2 status was compared among tumors with various histopathological features. Meanwhile, the ADC values of gastric cancers with positive and negative HER2 were compared. The mean ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors. The minimal ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors. The ADC values of gastric cancer correlate with the HER2 status. DWI can predict HER2 status and help in tailoring therapy for gastric cancer.

Elizabeth Li¹, Tim Lu¹, Alexandre Coimbra¹, and Alex de Crespigny ^1
1Genentech Inc., South San Francisco, CA, United States

Parametric mapping may provide estimates of extent of fibrosis in Crohn’s Disease (CD) patients but are subject to respiratory and peristaltic motion. Various image registration strategies and their impact on quality and robustness of parametric maps of gain of enhancement (GE) and magnetization transfer ratio (MTR) were compared. Healthy test-retest and CD image datasets were evaluated. Spatial registration improved quality and test-retest reliability of GE and MTR maps. In a limited cohort, extent of fibrosis estimated with GE and MTR maps were correlated. Cross validation of MR enterography-based fibrosis estimates with histological data will be conducted as data becomes available.

Michael Dean Repplinger¹, Perry J Pickhardt², Jessica B Robbins², Tim J Ziemlewicz², Doug R Kitchin², John Brian Harringa¹, Scott Hetzel³, and Scott Brian Reeder^2
1Emergency Medicine, University of Wisconsin - Madison, Madison, WI, United States, ²Radiology, University of Wisconsin - Madison, Madison, WI, United States, ³Biostatistics and Medical Informatics, University of Wisconsin - Madison, Madison, WI, United States

The aim of our study was to determine the test characteristics of an MRI protocol consisting of unenhanced, contrast-enhanced, and DWI to diagnose appendicitis. This was a prospective study including patients ≥12 years old being evaluated for appendicitis. We enrolled 226 patients; all images were interpreted by three fellowship-trained abdominal radiologists. Sensitivity and specificity (95% CI) were 95.2% (86.5-99%) and 89.4% (83.2-94%) for unenhanced MRI with DWI, 96.8% (89-99.6%) and 89.9% (83.7-94.4%) for CE-MRI, and 98.4% (91.6-100%) and 93.7% (88.3-97.1%) for CE-CT. We conclude that this MRI protocol is as accurate as CE-CT to diagnose appendicitis.

Susan Pritchard¹, Joe Paul¹, Giles Major^2,3, Luca Marciani^2,3, Penny Gowland¹, Robin Spiller^2,3, and Caroline Hoad^1,2
1Sir Peter Mansfield Imaging Centre, University of Nottingham, Nottingham, United Kingdom, ²Nottingham Digestive Diseases Centre, University of Nottingham, Nottingham, United Kingdom,³Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, United Kingdom

Assessment of colonic motility may be extremely useful in understanding the symptoms of constipation. Current techniques (manometry, cine-MRI) can only detect wall movements and not the effect this motion may have on mixing of colonic contents. We report the use of an MR tagging technique to assess flow and mixing in the human colon following ingestion of a 500ml macrogol preparation. This technique successfully identified differences in intracolonic mixing between 11 healthy and 11 constipated subjects and shows potential to generate novel insights into the physiology and mechanisms of disease and the environmental pressures on, and effects of, gut microbiota.

Xiaojuan Xiao¹, Baolan Lu¹, Xinyue Yang¹, Shenping Yu¹, Yanhong Yang¹, and Xu Yan^2
1Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China, People's Republic of, ²MR Collaboration NE Asia, Siemens Healthcare, Shanghai, China, People's Republic of

DCE-MRI, IVIM and DKI are emerging as promising tools for tumor diagnositic or therapy-predictive purposes. We performed these three methods in patients with rectal cancer simultaneously to find out their correlations. Our results showed significant correlation between perfusion sensitive parameters of IVIM and DCE-MRI. In addition, DKI parameters were calculated from data with a low (0-1000) and high (200-2000) b-value range, and the parameters from low b-value range showed significant correlation with IVIM parameters, but not for the high b-value range. 

Cheng Lu¹, Maneesh Dave², H. Matthew Cohn², Prateek Prasanna¹, Jeffrey Katz², Rajmohan Paspulati³, Anant Madabhushi¹, and Satish Viswanath^1
1Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ²Digestive Health Institute, University Hospital, Case Western Reserve University, Cleveland, OH, United States,³Dept of Radiology, University Hospital, Case Western Reserve University, Cleveland, OH, United States

We present initial results of identifying radiomic features (computer-extracted image features from radiography) from baseline diagnostic Magnetic Resonance Enterography (MRE) scans to discriminate patients who will and will not respond to initial therapy for Crohn’s Disease. Feature selection was employed to identify the most discriminatory features, followed by principal component analysis to identify an optimal combination of these features. In a cohort of 11 patients, the radiomic feature combination was able to successfully distinguish between responders and non-responders with only 1 misclassification. Multi-scale oriented gradient (Gabor) features appeared to best capture subtle inflammation-related imaging characteristics on MRE and hence most predictive of patient outcome. 

Shivani Pahwa¹, Ziang Lu¹, Sara Dastmalchian¹, Yun Jiang², Mital Patel³, Neal Meropol³, Mark Griswold⁴, and Vikas Gulani^5
1Radiology, Case Western Reserve University, Cleveland, OH, United States, ²Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ³Hematology and Oncology, University Hospitals Case Medical Center, Cleveland, OH, United States, ⁴Radiology and Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States, ⁵Radiology, University Hospitals Case Medical Center, Cleveland, OH, United States

Accurate delineation of tumor extent and early assessment of response to treatment are open challenges in imaging evaluation of colorectal tumors. Quantitative imaging methods as relaxometry have been explored to fulfill this unmet need, but not adopted in clinical practice due to long acquisition time.  In this feasibility study, we examined the relaxation time of rectal tumors, mesorectum and rectal wall using magnetic resonance fingerprinting (MRF)

Valentin Ratz¹, Tobias Wech¹, Andreas Schindele², Alexander Sauer¹, Alexander Dierks¹, Joachim Reibetanz³, Alfio Borzi², Thorsten Bley¹, and Herbert Köstler^1
1Institute of Diagnostic and Interventional Radiology, Unisversity Hospital Würzburg, Würzburg, Germany, ²Institute of Mathematics, University Würzburg, Würzburg, Germany, ³Department of General-, Visceral-, Vascular- and Pediatric Surgery, Unisversity Hospital Würzburg, Würzburg, Germany

Current 2D MR-defecography techniques lack information about lateral localized pathologies. The purpose of this project was to implement a dynamic 3D MR-defecography which covers a larger area and thereby gathers more detailed information on the anatomy during defecation. Therefore we implemented a radial 3D TrueFISP Stack of Stars sequence with density-weighting and view-sharing. The highly undersampled datasets, which we have acquired in 5 patients, were reconstructed using a modified FISTA compressed sensing algorithm. The proposed method allows for a dynamic 3D examination of the fast defecation process. Therefore the detection of lateral localized pathologies is possible as well.

Kathryn Murray¹, Ching Lam², Sumra Rehman³, Caroline Hoad¹, Luca Marciani², Carolyn Costigan¹, Melanie Lingaya², Rawinder Banwait², Stephen Bawden¹, Robin Spiller², and Penny Gowland^1
1Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, United Kingdom, ²NIHR Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, United Kingdom, ³University of Nottingham, Nottingham, United Kingdom

A link between FODMAP malabsorption and stress has been suggested. Here, the effects of corticotrophin releasing factor (CRF) on fructose malabsorption are investigated in this randomised, placebo-controlled, crossover study in healthy volunteers.  

Abdallah G. Motaal¹, Catharina S. de Jonge¹, Wouter V. Potters¹, Bram F. Coolen¹, Aart J. Nederveen¹, and Jaap Stoker^1
1Radiology Department, 3T Lab, Academic Medical Center, Amsterdam, Netherlands

Motility assessment of the small bowel using dynamic MRI can only be acquired with either a limited coverage of the intestines or relatively low temporal resolution, which obscures details of motion during contraction and relaxation. Compressed sensing and parallel imaging (CS-PI) techniques allow higher temporal resolution imaging by acquiring and reconstructing undersampled acquisitions. In this abstract we show that by using CS-PI, accelerations up to 7X could be achieved, which outperforms conventional approaches based on parallel imaging only. As a consequence, CS-PI provides a valuable tool for improved assessment of small bowel motility. 

Eamon K Doyle, MS¹, Jonathan M Chia, MS², Krishna S Nayak, PhD^3,4, and John C Wood, MD, PhD^4,5
1Biomedical Engineering, University of Southern California, Sierra Madre, CA, United States, ²Philips Healthcare, Cleveland, OH, United States, ³Electrical Engineering, University of Southern California, Los Angeles, CA, United States, ⁴Biomedical Engineering, University of Southern California, Los Angeles, CA, United States, ⁵Cardiology, Children's Hospital of Los Angeles, Los Angeles, CA, United States

R2 (1/T2) and R2* (1/T2*) are useful metrics related to tissue iron loads. Clinical iron estimation at 3T is limited by the achievable echo times in Cartesian spin echo and gradient echo imaging.  We present a modified CSI spectroscopy sequence robust to motion for high SNR liver R2* estimation with the potential for simultaneous R2 estimation.

Yanyan Xu¹, Hongliang Sun¹, Kaining Shi², and Wu Wang^1
1Radiology, China-Japan Friendship hospital, Beijing, China, People's Republic of, ²Philips Healthcare China, Beijing, China, People's Republic of

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been applied in rectal cancer for the purpose of characterizing tumor perfusion[1]. However, DCE-MRI should use intravenous contrast media based gadolinium, which will increase the risk of kidney systemic fibrosis[2]. The bi-exponential analysis in intravoxel incoherent motion (IVIM) model can separate microscopic circulation perfusion with pure water diffusion[3-4]. Correlation has been derived between the IVIM perfusion parameters f and D* and the classical perfusion parameters[5-6]. However, its relationship with DCE-MRI parameters in rectal cancer has not been clarified.

Yuki Kanazawa¹, Yuki Matsumoto², Hiroaki Hayashi¹, Tsuyoshi Matsuda³, Mungunbagana Ganbold⁴, and Masafumi Harada^4
1Tokushima University, Tokushima, Japan, ²School of Health Sciences, Tokushima University, Tokushima, Japan, ³MR Applications and Workflow, Asia Pacific GE Healthcare Japan Corporation, Hino, Japan, ⁴Department of Radiology and Radiation Oncology, Tokushima University, Tokushima, Japan

The purpose of this study was to development and evaluate a dual passive driver system to improve non-uniformity of liver MRE. This study was performed using a phantom and a volunteer. The standard deviation on unwrapped phase image (S.D._unwrap) for the dual driver system has shown higher values than that of a single system. Moreover, the shear stiffness value of a system having a high S.D._unwrap showed the highest correlation with actual measurement values (P < .05). In conclusion, MRE with a dual driver system may render it possible to obtain more detailed information for the evaluation of liver conditions.

Eric G. Stinson¹, Joshua D. Trzasko¹, Eric A. Borisch¹, Phillip M. Young¹, Joel G. Fletcher¹, and Stephen J. Riederer^1
1Radiology, Mayo Clinic, Rochester, MN, United States

Perianal fistula images with high spatial resolution, high SNR, and excellent fat suppression were achieved with a multi-TE interleaved acquisition and a constrained-phase graph cuts-based Dixon fat/water separation.

Stephanie Marchesseau¹, Sue-Ann P.L Ng², Andrea H.L. Low^2,3, YT Wang⁴, Jamie X.M Ho¹, Josh D. Schaefferkoetter¹, and John J. Totman^1
1Clinical Imaging Research Centre, NUS, Singapore, Singapore, ²Departement of Rheumatology and Immunology, SGH, Singapore, Singapore, ³Duke-National University, Singapore, Singapore,⁴Department of Gastroenterology and Hepatology, SGH, Singapore, Singapore

Systemic sclerosis (SSc) is a multi-system disease characterized by immune dysregulation, fibrosis and vascular damage that affects the gastrointestinal tract in most patients. In this study, we investigate simultaneous FDG-PET/MR imaging for the diagnosis of SSc GIT involvement. Our preliminary results show that FDG-PET can detect inflammation in the bowels while T1 MOLLI mapping could be able to distinguish healthy from fibrotic GIT tissue.

Yoshifumi Noda¹, Satoshi Goshima¹, Hideto Tomimatsu¹, Haruo Watanabe¹, Hiroshi Kawada¹, Nobuyuki Kawai¹, Hiromi Ono¹, Masayuki Matsuo¹, and Kyongtae T Bae^2
1Radiology, Gifu University Hospital, Gifu, Japan, ²Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, United States

To determine the ADC value and clinical-pathologic risk factors associated with postoperative local recurrence or distant metastases in patients with rectal cancer. The plasmatic CA19-9 level (P = 0.0027), pathological N stage (P = 0.0018), lymphatic invasion (P < 0.0001), and ADC value (P = 0.0076) were independently associated with postoperative local recurrence or distant metastases in the patients with rectal cancer. Among the several indicators, the tumor ADC values and plasmatic CA19-9 level can be useful for the preoperative prediction of high risk cases for postoperative local recurrence or distant metastases in patients with rectal cancer.

Inbal E Biton¹, Noa Stettner¹, Ayelet Erez², Alon Harmelin¹, and Joel R Garbow^3
1Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel, ²Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel, ³Biomedical Magnetic Resonance Laboratory, Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO, United States

Inflammatory bowel disease (IBD) is characterized by uncontrolled inflammation of the gastrointestinal tract [1]. Determining the inflammatory state of the colon is critical for defining the disease activity. Endoscopy in human IBD allows visualization of mucosal inflammation [2]. However, the technique is based on grading of the entire colon, which is operator dependent. The mucosa is very fragile, therefore endoscopic evolution is problematic. Therefore, the development of an improved, noninvasive, objective MRI technique may provide a non-invasive assessment tool to depict pathologies in the small intestinal mucosa and, more specifically, along the colon, and to assess the bowel wall and surrounding structures. In this study, dextran sodium sulphate (DSS) polymer treatment was used to induce acute colitis in mice that was subsequently characterized by multi-slice MR colonography.

Yi Li¹, Daniel Litwiller², Pauline Worters³, Ersin Bayram⁴, John MacKenzie¹, and Jesse Courtier^1
1Department of Radiology, University of California San Francisco, San Francisco, CA, United States, ²Global MR Applications and Workflow, GE Healthcare, Rochester, MN, United States, ³Global MR Applications and Workflow, GE Healthcare, Menlo Park, CA, United States, ⁴Global MR Applications and Workflow, GE Healthcare, Houston, TX, United States

MR enterography is the modality of choice for the imaging of inflammatory bowel disease, but presents unique challenges in the pediatric population, particularly with respect to motion degradation. Variable refocusing flip angle single shot fast spin echo (vrfSSFSE), an improvement upon the traditional single shot fast spin echo (SSFSE) sequence, allows for shortened acquisition times and improved contrast and spatial resolution.  Clinical use of vrfSSFSE in pediatric MR enterography has led to subjective improvements in image quality and has allowed for improved identification of many imaging findings related to inflammatory bowel disease.

Andrew Fry¹, Elspeth Whitby², and Peter Wright^1
1Medical Physics, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom, ²Academic Unit of reproductive and developmental medicine, University of Sheffield, Sheffield, United Kingdom

A balanced steady-state free precession (bSSFP) sequence gives excellent fluid/tissue contrast and allows rapid repeat acquisition of a single slice, resulting in a cine image dataset. We evaluate the bSSFP sequence to image fetal swallowing action and passage of fluid in the esophagus and airway in 7 human fetuses. Regurgitation of amniotic fluid is observed where major or total obstruction is present. Optimised bSSFP sequences are demonstrated at 1.5T and 3.0T and can be used in assessment of obstruction and swallowing in a wide variety of cases including esophageal atresia, neck masses, CHAOS and cleft palate. 

Sila Kurugol¹, Moti Freiman¹, Onur Afacan¹, Liran Domachevski², Jeanette M. Perez-Rossello¹, Michael J. Callahan¹, and Simon K. Warfield^1
1Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States, ²Nuclear Medicine, Rabin Medical Center, Petah-Tikva, Israel

Quantitative diffusion-weighted MRI (DW-MRI) has been increasingly used for the detection and characterization of abdominal abnormalities. However, respiratory, cardiac and peristalsis motion deteriorates robustness and reproducibility of parameter estimation in DW-MRI. Current solutions do not entirely correct for motion and have disadvantages such as increased scan time. In this work, we introduce a simultaneous image registration and model estimation (SIR-ME) framework for motion-compensated parameter estimation. The proposed method improved the goodness-of-fit by more than 50% and estimated model parameters more precisely, resulting in better discrimination between normal and diseased bowel loops, which will potentially impact clinical utilization.

Kim Sivesgaard¹, Maria Louise Jöhnk², Lars Peter Skovgaard Larsen¹, Michael Sørensen³, Stine Kramer³, Flemming Hansen², and Erik Morre Pedersen^1
1Department of Radiology, Aarhus University Hospital, Aarhus, Denmark, ²Department of Oncology, Aarhus University Hospital, Aarhus, Denmark, ³PET-centre, Aarhus University Hospital, Aarhus, Denmark

A whole body (WB) MRI protocol added to a dedicated liver MRI in one scan session, could alleviate the need for a PET/CT for staging patients prior to local treatment of colorectal liver metastases. With the aim of developing a disease optimised WB protocol, 30 patients with extra-hepatic metastases from colorectal cancer were prospectively recruited and scanned on a 1.5 T scanner and using a PET/CT scan within an average of 1.33 days as reference. Preliminary results show that combining a traditional whole body MRI protocol with DWIBS produces superior results compared to the traditional protocol alone.

Endre Grøvik^1,2, Kathrine Røe Redalen³, Sebastian Meltzer^3,4, Anne Negård⁵, Stein Harald Holmedal⁵, Anne Hansen Ree^3,4, Tryggve Holck Storås¹, Atle Bjørnerud^1,2, and Kjell-Inge Gjesdal^6
1The Intervention Centre, Oslo University Hospital, Oslo, Norway, ²Department of Physics, University of Oslo, Oslo, Norway, ³Department of Oncology, Akershus University Hospital, Lørenskog, Norway,⁴Faculty of Medicine, University of Oslo, Oslo, Norway, ⁵Department of Radiology, Akershus University Hospital, Lørenskog, Norway, ⁶Sunnmøre MR klinikk AS, Ålesund, Norway

The purpose was to evaluate the association between the dynamic change in R₂*, obtained from a multi-echo dynamic contrast-based acquisition, and clinicopathologic data in patients with rectal cancer. Twenty patients were examined using a high temporal resolution multi-echo EPI sequence. Dynamic R₂* images were calculated by assuming a mono-exponential dependence of signal change on echo-time, and parametric images representing the maximum peak change in R₂*, ΔR₂*-peak, were generated. Tumor ΔR₂*-peak significantly differentiate between rectal cancer patients with and without nodal metastases (P=0.01), with an area under the ROC curve of 0.94.