Electronic poster

Tuesday 13:30-15:30 Computer 92

13:30 4570. Gd-EOB-DTPA Enhanced MR Imaging of the Liver: Correlation with Morphological Severity of Cirrhosis and Hepatic Parenchyma Enhancement at Hepatobiliary Phase

Atsushi Higaki¹, Tsutomu Tamada¹, Akihiko Kanki¹, Yasufumi Noda¹, Hiroki Higashi¹, Takenori Yamashita¹, Katsuyoshi Ito<sup>1

1</sup>Radiology, Kawasaki Medical School, Kurashiki, Okayama, Japan

We evaluated the relationships between enhancement effects of liver parenchyma in hepatobiliary phase of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) enhanced MR imaging and MR imaging findings of cirrhosis change. Hepatic parenchymal enhancement in the HP of Gd-EOB-DTPA enhanced MR imaging did not necessarily decrease according to the morphological severity of cirrhosis. This fact may suggest that the hepatic uptake of Gd-EOB-DTPA depends on the preserved hepatocytes function rather than the severity in morphologic changes in cirrhosis.

14:00 4571. Diffusion-Weighted MR Imaging Improves Sensitivity of Lesion Detection Compared with Gadolinium Enhanced T1-Weighted Imaging in Patients with Suspected Liver Metastases from Neuroendocrine Tumours.

Mark Ingram¹, Toni Wallace², Erica Scurr², David J. Collins^2,3, Val Lewington⁴, Dow-Mu Koh<sup>2

1</sup>Department of Radiology, St George's Healthcare NHS Trust, Tooting, London, United Kingdom; ²Department of Radiology, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom; ³CRUK-EPSRC Cancer Imaging Centre, Institute of Cancer Research, Sutton, Surrey, United Kingdom; ⁴Department of Nuclear Medicine, Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom

In patients with neuroendocrine liver metastases, imaging determination of the size and distribution of metastatic disease is of value as it could influence the choice of therapy. We compared diffusion-weighted MR imaging (DW-MRI) and gadolinium-DTPA enhanced MR imaging for the detection of focal liver lesions in patients with suspected liver metastases arising from neuroendocrine tumours. DW-MRI was found to have a significantly higher diagnostic sensitivity (88%) compared with gadolinium-DTPA enhanced MR imaging (77%) for lesion detection in this patient population (p = 0.001, McNemar test).

14:30 4572. How to Reduce So-Called Ringing Artifacts in Primovist-Enhanced MR Imaging

Akihiro Tanimoto¹, Nobuya Higuchi², Akihisa Ueno², Shigeo Okuda<sup>2

1</sup>Department of Diagnostic Radiology, School of Medicine, Keio University , Tokyo, Japan; ²Department of Diagnostic Radiology, School of Medicine, Keio University, Tokyo, Japan

So-called gringing artifactsh are often associated with Primovist-enhanced dynamic MR imaging, aggravating the diagnosis for focal hepatic lesions. To analyze the cause of this phenomenon, various scan and data acquisition parameters were tested using a newly created simulation software on the personal PC. The simulation study revealed that square matrices, short scanning time, slow infusion rate, and sequential view ordering were effective measures to reduce the artifacts. These results were confirmed in the clinical practice of Primovist-enhanced MR imaging.

15:00 4573. Initial Clinical Experience with FRFSE Triple Echo Dixon (FRFTED) for Breath-Hold Fast Dixon Abdominal MR Imaging

Russell Norman Low^1,2, Jingfe Ma³, Neeraj Panchal<sup>1,2

1</sup>Sharp and Children's MRI Center, San Diego, CA, United States; ²San Diego Imaging, San Diego, CA, United States; ³Department of Imaging Physics, The University of Texas MD Anderon Cancer Center, Houson, TX, United States

This study evaluates a prototype breath hold fast recovery fast spin echo (FSE) based Dixon pulse sequence that provides superior fat suppression less sensitive to magnetic field inhomogeneities.

Wednesday 13:30-15:30 Computer 92

13:30 4574. Evaluation of a Non-Enhanced MRI Protocol Compared to Gadolinium-Enhanced MRI for Hepatocellular Carcinoma

Andrew Dean Hardie<sup>1

1</sup>Radiology, Medical University of South Carolina, Charleston, SC, United States

MRI is accurate for identifying hepatocellular carcinoma however gadolinium chelates are contraindicated in patients with severe renal dysfunction due to the risk of Nephrogenic Systemic Fibrosis. There is a need to develop clinically usefull non-contrast MRI techniques to image these patients. Diffusion-weighted imaging and T2* weighted imaging offer the ability to identify tumors in cirrhotic patients with an accuracy similar to gadolinium MRI.

14:00 4575. Evaluation of a New Multi-Modality Visualization Tool for Investigation of Hepatic Metastases from Colorectal Cancer

Laurent Milot¹, Kayan Ma², Erin Efford¹, Gal Sela², Carolyn Maloney¹, Susan Crisp¹, Natalie Coburn³, Masoom Haider¹, Cameron Piron², Calvin Law³, Don Plewes<sup>4

1</sup>Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; ²Sentinelle Medical Inc, Toronto, Ontario, Canada; ³Department of Surgical Oncology, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada; ⁴Department of Imaging Research, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada

Ultrasound and MRI provide complimentary information useful in pre-operative planning for surgical resection of hepatic metastases from colorectal cancer. This study investigates the value of real-time co-registration of preoperative MRI and ultrasound images to determine if this method improves the ability to localize suspicious targets under ultrasound, using MRI as a gold standard. Co-registered MRI/ultrasound imaging yielded a significant increase in the number of targets successfully localized compared to ultrasound examination alone. Co-registered imaging was particularly effective in localizing small lesions (less than 5 mm) which were difficult to identify under conventional ultrasound examination.

14:30 4576. Pharmacokinetics and Safety of Gadobenate Dimeglumine in Patients from 2 to 5 Years of Age

Gianpaolo Pirovano¹, Mieczyslaw Pasowicz², Miles A. Kirchin³, Ningyan Shen⁴, John R. Parker⁵, Alberto Spinazzi<sup>1

1</sup>Medical Affairs, Bracco Diagnostics Inc., Princeton, NJ, United States; ²Radiology, John Paul II Hospital, Kracow, Poland; ³Medical Communications, Bracco Imaging, Milan, Italy; ⁴Biometrics, Bracco Diagnostics Inc., Princeton, NJ, United States; ⁵Medical Communications, Bracco Diagnostics Inc., Princeton, NJ, United States

15 subjects aged 2-5 years were enrolled in a pharmacokinetic study and received 0.1 mmol/kg bw gadobenate dimeglumine. Pharmacokinetic parameters were calculated from the blood Gd concentration-time data using compartmental and noncompartmental techniques. At 6 hours after gadobenate dimeglumine administration, all subjects¡¦ residual Gd in blood was close to 1.0 ƒÝg/mL, indicating that Gd was successfully cleared from the blood. No differences in whole blood or urinary pharmacokinetic parameters were observed between pediatric subjects 2 to 5 years when compared to adult subjects studied in previously.

15:00 4577. MRI of Infiltrative HCC- Characterization of Imaging Features in Association with Clinical Presentation

Bobby Kalb¹, Douglas Vander Kooi², Daniel Karolyi¹, Bhavika Patel¹, Khalil Salman¹, Diego R. Martin<sup>1

1</sup>Radiology, Emory University, Atlanta, GA, United States; ²Radiology, Langley Airforce Base, Hampton, VA, United States

Infiltrative-type of HCC (I-HCC) is an incurable, less common growth pattern of HCC that may mimic fulminant CLD. Distinction of I-HCC on MRI is critical for optimal management and to avoid inadvertent transplantation of incurable disease, however imaging features may be atypical with poor visibility of tumor extent on postcontrast images. We have categorized MR imaging and pathologic features of I-HCC, and found tumor conspicuity to be most pronounced on T2-weighted images, with portal venous tumor thrombus present in all cases. These findings are important to help improved clinical application of MRI in the setting of CLD.

Thursday 13:30-15:30 Computer 92

13:30 4578. Computational Analysis of Flow in the Portal Vein of Normal Subjects and Patients Using MRI and CFD

Stephanie M. George¹, Diego R. Martin², Don P. Giddens<sup>1

1</sup>Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, United States; ²Department of Radiology, Emory University School of Medicine, Atlanta, GA, United States

With the incidence of chronic liver disease (CLD) increasing the need for improved diagnostic measurements has increased. Magnetic resonance imaging (MRI) and phase-contrast MR offer noninvasive techniques which provide both high quality anatomical and hemodynamic data. The use of these data coupled with computational fluid dynamics (CFD) to provide detailed flow field information is a novel approach. This study examines a small number of normal subjects and patients comparing PC-MR measured portal venous hemodynamic parameters including velocity and flow rate and computational results. This work demonstrates the feasibility of coupling MRI and CFD to investigate the altered hemodynamics in CLD.

14:00 4579. Relationship Between Gd-EOB-DTPA MRI and Tc-99m-GSA for Quantitative Evaluation of Liver Function

Jumpei Suyama¹, Shouei Sai¹, Masaaki Kawahara¹, Yoshimitsu Ohgiya¹, Noritaka Seino¹, Masanori Hirose¹, Takehiko Gokan<sup>1

1</sup>Department of Radiology, Showa University School of medicine, TOKYO, Japan

The purpose of this study is to evaluate relationship between Tc-99m-GSA scintigraphy and 3T-MRI using Gd-EOB-DTPA for quantitative liver function. Nineteen patients with liver tumor were included in this study. There was significant correlation between LHL15 and the increased ratio of signal intensity at 4min (r=0.80, p<0.00005), and the increased ratio at 20 min were also well correlated (r=0.67, p<0.0005). It could be possible to use Gd-EOB-MRI for quantitative liver function as well as Tc-99m-GSA scintigraphy.

14:30 4580. In Vivo Imaging of Mouse Pancreas Utilizing Ultra High Field of 14T and Manganese Enhanced MRI

Riikka J. Immonen¹, Smaragda Lamprianou², Laurent Lecomte¹, Laurent Vinet², Paolo Meda², Rolf Gruetter<sup>1,3

1</sup>Laboratory for functional and metabolic imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland; ²Department of Cell Physiology and Metabolism, University of Geneva, Geneva, CH-1210, Switzerland; ³Department of Radiology, University of Geneva and Lausanne, Geneva/Lausanne, CH-1210/CH-1015, Switzerland

In vivo imaging of pancreas with high resolution is challenging. In diabetes pancreatic β–cell mass and function are gradually lost. MRI methodology to monitor this in vivo is needed. We utilized 14.1T and manganese enhanced MRI to image the mouse gland in vivo, and to examine the changes in manganese signal during β–cell stimulation by glucose. In multi-slice images with 50*50*300μm resolution, acquired <20min, we were able to distinguish pancreatic main vessels and exocrine ducts, and Mn highlighted spots, possibly pancreatic islets. We also demonstrated with T1-wt inversion recovery, lower resolution technique, the manganese enhancement before and after glucose stimulus.

15:00 4581. Proton MRS of Hepatic Ischemia/Reperfusion Injury in an Experimental Rat Model

April M. Chow^1,2, Kannie W.Y. Chan^1,2, Shu Juan Fan^1,2, Jerry S. Cheung^1,2, Ed X. Wu<sup>1,2

1</sup>Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; ²Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China

Hepatic ischemia/reperfusion injury (IRI) occurs during liver transplantation, tumor resection, hemorrhagic shock and veno-occlusive disease. Biochemical changes caused by hepatic IRI lead to hepatocellular remodeling, including cellular regeneration or irreversible programmed cell death. In this study, we demonstrated that the alteration in the metabolism of choline-containing compounds (CCC) accompanied with hepatic IRI could be monitored using ¹H MRS. The CCC peak may be useful in evaluating the regeneration of hepatocytes upon hepatic IRI. ¹H MRS has shown to be a potential tool for identify and quantify metabolic changes in liver in vivo noninvasively.

MR Upper Abdomen II

Hall B Monday 14:00-16:00 Computer 93

14:00 4582. Gd-EOB-DTPA Enhanced-MRI of the Liver: Dynamic Enhancement Compared with Gd-DTPA, Preliminary Experience

Natasha Wehrli¹, Hersh Chandarana¹, Ely Felker¹, Bachir Taouli, <sup>1,2

1</sup>NYU Medical Center, New York, NY, United States; ²Mount Sinai School of Medicine, New York, NY, United States

Gd-EOB-DTPA is a recently FDA approved liver-specific contrast agent which combines a dynamic and a delayed phase of enhancement, approved to be used at a lower dose compared to extracellular agents (0.025 vs. 0.1 mmol/kg). In this study, we compared hepatic vascular conspicuity obtained with single and double dose Gd-EOB vs. Gd-DTPA at the dynamic phase, and found significantly better liver-to-vessel contrast ratio with Gd-DTPA compared to single dose Gd-EOB-DTPA. The liver-to-vessel contrast ratio improved when using a double dose Gd-EOB-DTPA.

14:30 4583. Tracer-Kinetic Analysis of Gd-EOB-DTPA in the Liver with a Dual-Inlet Two-Compartment Uptake Model

Steven Sourbron¹, Wieland Sommer, Christoph Zech, Maximilian Reiser, Karin Herrmann

¹Ludwig-Maximilian-University Munich, Munich, Bavaria, Germany

A dual-inlet one-compartment uptake model is developed for DCE-MRI with Gd-EOB-DTPA in the liver. The model generalizes the one-compartment model for the liver, providing one new parameter: the intracellular uptake rate (KI). Data in normal appearing liver tissue of 25 patients shows that the uptake model fitted all ROI curves accurately, and provided values in the expected range for all known parameters. The average value for KI was 1.7/100/min, with a relatively narrow range of normality. The method may present a new and practical paradigm in functional liver MRI, producing quantitative measures of both perfusion and hepatobiliary function.

15:00 4584. Free-Breathing Dynamic Contrast-Enhanced Abdominal Imaging Using Navigator Gating and Adaptive Navigator Correction

Anja C.S. Brau¹, Yuji Iwadate², Moritz Kircher³, Shreyas Vasanawala³, Robert Herfkens<sup>3

1</sup>Applied Science Lab, GE Healthcare, Menlo Park, CA, United States; ²Applied Science Lab, GE Healthcare, Hino, Japan; ³Radiology, Stanford University, Palo Alto, CA, United States

Dynamic contrast-enhanced (DCE) 3D T1w MRI is routinely used in abdominal imaging for characterization of liver lesions. Each contrast-enhanced phase is typically acquired within a breath-hold; however, this multi-breath-hold requirement faces several drawbacks. In this work, navigator gating is combined with adaptive navigator correction (“slab following”) to prospectively adjust slab location based on measured motion, with the goal of improving the image quality and acquisition efficiency of navigated 3D DCE liver imaging. Initial contrast-enhanced clinical results with this method are presented.

15:30 4585. Predicting Differentiation of Hepatocellular Carcinoma at Pre-Transplant MRI in Patients Undergoing Orthotopic Liver Transplantation

Stella K. Kang¹, Emma Robinson¹, Ramya Srinivasan¹, Bachir Taouli^1,2, Hersh Chandarana<sup>1

1</sup>Radiology, NYU Langone Medical Center, New York, NY, United States; ²Radiology, Mount Sinai Medical Center, New York, NY, United States

In patients undergoing orthotopic liver transplantation, preoperative MR imaging characteristics in hepatocellular carcinoma were examined, including T1 and T2 signal intensity, diffusion weighted imaging, and dynamic contrast enhanced kinetics and their relationship with histopathologic grade was assessed. DynaCAD, commercially available software, was utilized to examine enhancement kinetics of each tumor. Poorly differentiated HCCs had lower time to peak and higher rate of enhancement. T1 hypointensity also showed correlation with poorly differentiated tumors. No other qualitative or quantitative feature including DWI was useful in predicting HCC differentiation.

Tuesday 13:30-15:30 Computer 93

13:30 4586. Evaluation of Uptake and Excretion of Gd-EOB-DTPA in Normal and Cirrhotic Livers

Tsutomu Tamada¹, Atsushi Higaki¹, Akihiko Kanki¹, Tomohiro Sato¹, Kazuya Yasokawa¹, Katsuyoshi Ito<sup>1

1</sup>Dept. of Radiology, Kawasaski Medical School, Kurashiki-city, Okayama, Japan

We assessed differences in enhancement effects of liver parenchyma and activity of biliary and renal excretion between normal and cirrhotic livers on Gd-EOB-DTPA-enhanced MR imaging. It will be important to know that hepatic enhancement effects in the HP are decreased in patients with severe cirrhosis, probably due to impaired uptake of Gd-EOB-DTPA by hepatocytes, and biliary excretion is impaired in cirrhotic livers in comparison with normal livers while renal excretion of Gd-EOB-DPTA can be increased, probably due to the compensatory mechanism.

14:00 4587. MR Elastography of Peritoneal Tumor

Russell Norman Low^1,2, Matthew J. Austin³, Lloyd Estkowski⁴, Richard Ehman<sup>5

1</sup>Sharp and Children's MRI Center, San Diego, CA, United States; ²San Diego Imaging, San Diego, CA, United States; ³Radiology, Universit y of California at San Diego, San Diego, CA, United States; ⁴General Electric Healthcare; ⁵Mayo Clinic

We present our intial clinical experience using MR elastography in oncology patients to depict peritoneal tumor. Peritoneal tumors in the upper abdomen demonstrated increased mean shear stiffness compared to the liver as was depicted on color encoded spatial maps. On a per patient basis MRE demonstrated a .87 sensitivity, .78 specifity, and .82 accurcy. In the quantitative anlysis the mean shear stiffness of peritoneal tumor was 4.43 kPA and the mean shear stiffness of the adjancent liver was 2.36 kPa.

14:30 4588. T2-Weighted Liver MRI at 3T Using a BLADE Technique: Comparison with a Standard Rectilinear T2-Weighted Sequence for Image Quality and Lesion Detection

Andrew B. Rosenkrantz¹, Lorenzo Mannelli¹, David Mossa¹, James Babb<sup>1

1</sup>Radiology, NYU Langone Medical Center, New York, NY, United States

T2WI of the liver was performed in 28 patients at 3T using standard rectilinear and BLADE k-space trajectories. Compared with standard T2WI, BLADE demonstrated significant improvements in in-plane motion, other ghosting artifact, liver edge sharpness, vessel sharpness, and flow suppression, a trend toward improved B1-inhomogeneity artifact, and no difference in through-plane motion. BLADE demonstrated a significant improvement in specificity for liver lesion detection but no difference in sensitivity. ROI analysis showed significantly improved relative contrast between the liver and focal lesions with BLADE. We conclude that BLADE achieved significant improvements in artifacts, image quality, and specificity for liver lesion detection.

15:00 4589. Assessment of Liver Oxygenation with BOLD MRI at 3T. Feasibility Study

Peter Beddy¹, Richard Black¹, Lorenzo Mannelli², Ilsa Joubert¹, Andrew Priest¹, David J. Lomas<sup>1

1</sup>Radiology, University of Cambridge and Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom; ²Radiology, University of Cambridge and Addenbrookes Hospital, Cambridge, Cambridgeshire, United Kingdom

BOLD MRI is a potential non-invasive method for assessing tissue oxygenation in a wide range of tissues. This work develops a method for oxygen challenge based BOLD imaging of the liver at 3T in a group of volunteers and demonstrates that acceptable results and low variability can be achieved using both breath-hold and respiratory triggered multi-echo gradient echo acquisitions.

Wednesday 13:30-15:30 Computer 93

13:30 4590. Alteration in the Conjugation Pattern of Bile Acids in Human Bile During Cholestasis: A ¹H MRS Study

Tedros Bezabeh¹, Omkar B. Ijare¹, Nils Albiin², Annika Bergquist³, Urban Arnelo⁴, Matthias Löhr³, Johannes R. Hov⁵, Ian CP Smith<sup>1

1</sup>National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; ²Radiology, Karolinska Institutet, Stockholm, Sweden; ³Gastroenterology and Hepatology, Karolinska Institutet, Stockholm, Sweden; ⁴Surgery, Karolinska Institutet, Stockholm, Sweden; ⁵Medicine, Oslo University Hospital Rikshospitalet, Oslo, Norway

Conjugation of bile acids with amino acids glycine and taurine is an important phenomenon in bile formation. In healthy humans, the ratio of glycine- to taurine-conjugated bile acids is generally 3:1, and this ratio is altered in cholestatic conditions. We analyzed bile samples from patients with various cholestatic diseases and found that the median of the above ratio was 2.23:1. This alteration could be attributed to the elevation in the levels of taurine-conjugates or reduction in the levels of glycine-conjugates. Such alterations can be easily detected by ¹H MRS and the technique could be valuable in the diagnosis of diseases related to bile acid synthetic defects.

14:00 4591. Are Dynamic First-Pass Enhancement Properties of Gadoxetic Acid (Gd-EOB-DTPA) Comparable to Gadopentetate Dimeglumine (Gd-DTPA) in Hepatocellular Carcinoma (HCC)?

Mi-Suk Park¹, Myeong-Jin Kim², Ki Whang Kim<sup>1

1</sup>Department of Diagnostic Radiology, Yonsei University Health System Severance Hospital, Seoul, Korea, Republic of; ²Severance hospital

In this abstract, we compared dynamic first-pass enhancement properties of gadoxetic acid with that of gadopentetate dimeglumine in the patients with HCC. Gadoxetic acid-enhanced MRI showed more rapid wash-out of HCC, stronger enhancement of hepatic parenchyma, and weaker enhancement of vessels than the standard Gd-chelate enhanced MRI.

14:30 4592. Diffusion-Weighted Imaging: Diagnostic Value in the Assessment of Intrahepatic Metastases of Hepatocellular Carcinoma

Jeong-Sik Yu¹, Jae-Joon Chung, Joo Hee Kim, Ki Whang Kim

¹Radiology, Gangnam Severance Hospital, Seoul, Korea, Republic of

For the hepatocellular carcinomas, the presence of small satellite lesions is an important determinant of a patient¡¯s prognosis and therapeutic planning. Through the results of our study DWI is superior to dynamic MRI in the detection and characterization of subcentimeter lesions and can be added to strengthen the accuracy in the MRI assessment of intrahepatic metastases of HCCs. DWI could overcome the inherent drawbacks of dynamic MRI for the hypervascular pseudolesions or obscured tumoral vascularities by the perfusional changes in the background parenchyma serve as a complementary tool for patients examined by dynamic MRI.

15:00 4593. Gd-EOB-DTPA Combined with Gd-DTPA: Hepatobiliary Contrast with Familiar Hepatic Dynamic Contrast Enhancement

Jesse L. Wei^1,2, Kimiknu Mentore¹, Martin P. Smith^1,2, Neil M. Rofsky<sup>1,2

1</sup>Radiology, Beth Israel Deaconess Medical Center, Boston, MA, United States; ²Harvard Medical School, Boston, MA, United States

Administration of Gd-EOB-DTPA using the recommended dose for hepatobiliary imaging results in an unfamiliar "washed out" appearance of the liver on dynamic contrast enhanced (DCE) imaging. This likely results from increased background hepatic enhancement due to early hepatobiliary uptake. Injection of a combination of Gd-EOB-DTPA in conjunction with an extracellular contrast agent provides the 20-minute delayed hepatobiliary phase, while preserving the familiar vascular contrast and lesion conspicuity compared to background liver on DCE images.