Functional MRI of the Abdomen
Thursday 23 April 2009
Room 316A 13:30-15:30


Harriet C. Thoeny and Thomas C. Lauenstein

13:30 659. Changes of Small Bowel Peristalsis in Patients with Crohns Disease
    Michael A. Patak1, Christian Waldherr1, Christophoros Stoupis2, Sukru Mehmet Erturk3, John M. Froehlich1
Institute of Radiology, Inselspital, University Hospital, Bern, Switzerland; 2Kreisspital, Männedorf, Switzerland; 3Dept of Radiology, Sisli Etfal Hospital, Istambul, Turkey
    Lesions of active Crohns disease are often accompanied by motility disorders, as has been described in fluoroscopy. Therefore, we hypothesized that the addition of cine-MRE to static MRE allows the detection of motility changes in CD and helps to detect CD related lesions of the small bowel wall. 40 consecutive patients with biopsy proven CD were included retrospectively and assessed for motility alterations using cine-MRE. Cine MRE confirms localized small-bowel motility changes in patients with clinically active Crohns disease. Compared to standard MRE alone a significant increase of active lesions was noted using cine MRE.
13:42 660. Evaluation of Diffusion-Weighted MR Imaging for Detection of Bowel Inflammation in Patients with Crohn`s Disease: A Pilot Study
    Aytekin Oto1, Fang Zhu1, Kirti Kulkarni1, Masatoshi Hori1, Arda Kayhan1, Gregory S. Karczmar1, Jerrold R. Turner2, David Rubin3
Department of Radiology, The University of Chicago, Chicago, IL, USA; 2Department of Pathology, The University of Chicago, Chicago, IL, USA; 3Department of Medicine, The University of Chicago, Chicago, IL, USA
    The purpose of this study was to determine the feasibility of diffusion weighted MR imaging (DWI) in detection of bowel inflammation and investigate the changes in apparent diffusion coefficient (ADC) values in the inflamed bowel in Crohn`s disease. Eleven patients were included. Two radiologists reviewed DWI images and ADC maps to evaluate for inflammation in each bowel segment and measured ADC values. Endoscopy and pathology results were correlated with DWI findings. The results showed DWI was a feasible technique for detection of inflammation in patients with Crohn's disease. ADC values were decreased in the inflamed bowel segments indicating restricted diffusion.
13:54 661. Magnetic Resonance Imaging for the Assessment of Gastro-Esophageal Junction
    Jelena Curcic1, Reto Treier1, Elad Kaufman2, Zsofia Forras-Kaufman2, Mark Fox2, Werner Schwizer2, Michael Fried2, Peter Boesiger1
Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland; 2Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
    Gastro-esophageal junction (GEJ) is the main defense mechanism against acid reflux. Its competence is the most fundamental in preventing clinical manifestations of gastro-esophageal reflux disease (GERD). Magnetic resonance imaging (MRI) combined with high-resolution manometry (HRM) as reference technique was used to evaluate the structure and function of the GEJ in healthy volunteers and GERD patients. Anatomic and dynamic scans were performed alternately before and after ingestion of a high-caloric meal. GEJ area was reconstructed in 3D and the insertion angle of the esophagus into the stomach was calculated. On dynamic MR images reflux events could be observed and analyzed.
14:06 662. Development and Positive Contrast Imaging of an MR-Visible Mesh-Implant for Repair of Abdominal Hernia
    Nils A. Kraemer1, Jens Otto2, Michael Hodenius3, Ioana Slabu3, Martin Baumann3, Uwe Klinge2,3, Andreas Muellen4, Boris Obolenski4, Rolf W. Guenther1, Gabriele A. Krombach1
Diagnostic Radiology, University Hospital Aachen, Aachen, Germany; 2Department of Surgery, University Hospital Aachen, Germany; 3Helmholtz Institute for Applied Medical Engineering, University of Technology Aachen, Germany; 4FEG Textiltechnik Forschungs- und Entwicklungsgesellschaft mbH, Aachen, Germany
    Polymer meshes are frequently implanted for surgical treatment of hernia. As, these meshes cannot be depicted with conventional radiological methods, aim of this study was to develop an MR-visible mesh implant. After incorporating superparamagnetic nanoparticles of ferrofluids into the mesh-filaments, susceptibility artefacts enabled delineation of the mesh. As intra-abdominal air and scar tissue present with hypointense signal intensities too, positive contrast of these susceptibilities was achieved by using inversion-recovery with ON-resonant water suppression (IRON) sequences. In phantoms and animal corps, the ferrous mesh was clearly delineated using IRON-imaging. Consequently, this method can help to reveal frequent post-surgery mesh related problems.
14:18 663. Functional Monitoring of Small Bowel Motility: Comparison of Spasmolysis Induced by Glucagon or Buscopan
    John M. Froehlich1, Muriel Daenzer1, Constantin von Weymarn1, Sukru Mehmet Erturk2, Christoph L. Zollikofer3, Michael A. Patak1
Institute of Radiology, Inselspital, University Hospital, Bern, Switzerland; 2Dept of Radiology, Sisli Etfal Hospital, Istambul, Turkey; 3Institute of Radiology, Kantonsspital, Winterthur, Switzerland
    Cross-sectional imaging of the abdominal organs suffers from peristaltic movement artifacts justifying the administration of spasmolytic drugs prior to imaging. Buscopan or glucagon, are being used in the large majority of cases. In this prospective clinical MR study we characterized and compared intraindividually the pharmacological profile of the two drugs by measuring the small-bowel cross-sectional diameter over time. While paralysis was reached rapidly with both drugs, glucagon was more reliable in achieving a complete arrest and lasted roughly three times longer than Buscopan. MRI is a reliable and reproducible method to quantify and analyze small bowel motility.
14:30 664. DTI of the Kidney at 3T - Protocol Evaluation, Reproducibility and Comparison to 1.5T
    Mike Notohamiprodjo1, Annie Horng1, Ulrike Attenberger1, Olaf Dietrich1, Henrik J. Michaely2, Karin A. Herrmann1, Maximilian F. Reiser1, Christian Glaser1
Institute for Clinical Radiology, University Hospitals Munich, Munich, Bavaria, Germany; 2Institute for Clinical Radiology, University Hospital, Mannheim, Bavaria, Germany
    The purpose of this study was to assess the feasibility of DTI of the kidney at 3T. Mean Fractional Anisotropy (FA)-values at 3T were not significantly different to 1.5T-measurements. Signal-to-noise-ratio and contrast-to-noise-ratio for cortex and medulla were significantly higher at 3T. However, medullary FA was less reproducible than FA of the cortex and 1.5T-measurements provided slightly lower Apparent diffusion coefficient (ADC)-values. For calculation of FA, acquisition of 2 b-values and 6 diffusion-directions appeared sufficient. DTI of the kidney may become a valuable tool for studying renal microarchitecture, however a certain field-strength associated variability and varying reproducibility should be considered.
14:42 665. Diffusion-Weighted Imaging for the Diagnosis of Bland Versus Tumor Thrombosis in the Portal and Renal Veins
    Jignesh M. Patel1, Elizabeth M. Hecht1, Danny C. Kim1, James S. Babb1, Bachir Taouli1, Ruth P. Lim1
Radiology, NYU Langone Medical Center, New York, NY, USA
    Differentiating bland from tumor thrombus is essential for appropriate management. We assessed the diagnostic performance of DWI for the differentiation of bland versus tumor thrombus in renal and hepatic malignancies. The ability to distinguish bland from tumor thrombus on high b-value DWI images was significant with an overall sensitivity, specificity, NPV and PPV of 0.87, 0.89, 0.73 and 0.95 respectively. In addition, the mean ADC was significantly lower in tumor thrombus (1.16 x 10-3 mm2/sec) when compared to bland (1.71 x 10-3 mm2/sec), p< 0.001.
14:54 666. Differentiation of Pancreas Carcinoma from Healthy Pancreatic Tissue Using a Wide Range of B-Values: Comparison of ADC and IVIM Parameters
    Andreas Lemke1, Lothar Rudi Schad1, Frederik Laun2, Bram Stieltjes3
Chair in Computer Assisted Clinical Medicine, University of Heidelberg, Faculty of Medicine, Mannheim, Germany; 2Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany; 3Department of Radiology, German Cancer Research Center, Heidelberg, Germany
    DWI was performed to determine changes of diffusion and microperfusion in healthy pancreatic tissue and pancreatic cancer using the IVIM-approach. The perfusion fraction f, the diffusion coefficient D and the pseudo diffusion coefficient D* were extracted from six healthy volunteers and six patients with histologically proven pancreatic carcinoma and were compared to ADC values. The perfusion fraction in pancreatic carcinoma was significantly lower than in healthy pancreatic tissue (p=0.002) in contrast to D and D* (p>0.5). Also, f was more sensitive then the low b-value ADC (p=0.008). The high b-value ADC showed no significant difference (p=0.064) between the two groups.
15:06 667. Longitudinal Assessment of Renal Fibrosis by Diffusion Weighted MRI: A Study in Unilateral Ureteral Obstruction (UUO) Mice Model
    Osamu Togao1, Shigehiro Doi2, Makoto Kuro-o2, Masaya Takahashi1
Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA; 2Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
    Renal fibrosis is the final common pathology of most progressive renal disease such as diabetic nephropathy and glomerulonephritis. Renal fibrosis has been widely investigated in an established animal model with unilateral ureteral obstruction (UUO). In the present study, we investigated the progression of the renal fibrosis in the animal model longitudinally by T2-weighted imaging (T2WI) and diffusion weighted imaging (DWI) to test whether MRI could provide metrics for detection and evaluation of the severity of renal fibrosis.
15:18 668. Diffusion Tensor Imaging of Renal Ischemia/Reperfusion Injury
    Jerry S. Cheung1,2, Shu Juan Fan1,2, April M. Chow1,2, Ed X. Wu1,2
Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China; 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China
    Renal ischemia/reperfusion injury (IRI) is a major cause of acute renal failure in native and in transplanted kidneys. IRI in kidney associated with transplantation may also influence early graft function and late changes. Recently, anisotropy measurement with diffusion tensor imaging (DTI) has been found to provide additional information about functional and structural status of kidney. In this study, we aim at characterizing diffusion properties of kidney with mean diffusivity (MD) and fractional anisotropy (FA) in an experimental rat model of renal IRI. The experimental results demonstrated that DTI is useful in identifying renal IRI by characterizing the changes in MD and FA.