Joint Annual Meeting ISMRM-ESMRMB 2014 10-16 May 2014 Milan, Italy

Hepatobiliary 1

Monday 12 May 2014
Blue 1 & 2  14:15 - 16:15 Moderators: Diego Hernado, Ph.D., Kartik S. Jhaveri, M.D.

14:15 0137.   Hyperpolarized [1,3-13C2]ethyl acetoacetate is a novel diagnostic metabolic marker of liver cancer.
Sonia Colombo Serra1, Pernille Rose Jensen2, Luigi Miragoli1, Magnus Karlsson2, Claudia Cabella1, Luisa Poggi1, Luca Venturi3, Fabio Tedoldi1, and Mathilde Lerche2
1Centro Ricerche Bracco, Bracco Imaging SpA, Colleretto Giacosa, Torino, Italy, 2Albeda Research, Copenhagen, Copenhagen, Denmark, 3CEIP, University of Torino, Colleretto Giacosa, Torino, Italy

Hepatocellular carcinoma (HCC) is most often found in cirrhotic livers and can be hardly diagnosed relying on anatomical information alone. Magnetic resonance is commonly used to identify anatomical lesions, but can also provide information on cellular metabolism by an emerging method that uses 13C labeled hyperpolarized molecules. This study aimed at probing the potential of hyperpolarized [1,3-13C2]ethyl acetoacetate as a metabolic marker of HCC. A liver cancer implanted in rats is diagnosed due to a higher substrate-to-product ratio in tumors than in healthy livers demonstrating that the metabolism of the liver isoform of carboxyl esterase can be monitored in vivo.

14:27 0138.   Agreement of 2-, 3-, 4-, 5- and 6-echo MRI-PDFF with MRS-PDFF in 580 adults with known or suspected non-alcoholic fatty liver disease (NAFLD)
Elhamy R Heba1, Claude B Sirlin2, Tanya Wolfson3, Anthony Gamst3, Rohit Loomba4, and Michael S Middleton2
1Radiology, UCSD, san diego, CA, United States, 2Radiology, UCSD, San Diego, CA, United States, 3UCSD, San Diego, CA, United States, 4Internal medicine, UCSD, San Diego, CA, United States

This study was done to compare the agreement of different MRI-PDFF liver fat quantification analysis methodologies in 580 adults with known or suspected non-alcoholic fatty liver disease (NAFLD), using MRS-PDFF as reference standard. We found that 3-, 4-, 5- and 6-echo MRI accurately quantify hepatic PDFF in adults, with 3-echo MRI informally showing the closest and 2-echo MRI the worst agreement.

14:39 0139.   Differentiation of hypointensity nodules on gadoxetic acid-enhanced hepatobiliary phase MRI using non-balanced spin-echo SSFP (T2FFE)
Masami Yoneyama1, Masanobu Nakamura2, Taro Takahara3, Thomas Kwee4, Yukihisa Takayama5, Akihiro Nishie5, Atsushi Takemura2, Yasutomo Katsumata2, Makoto Obara2, Satoshi Tatsuno1, and Seishi Sawano1
1Yaesu Clinic, Tokyo, Japan, 2Philips Electronics Japan, Tokyo, Japan, 3Tokai University School of Engineering, Kanagawa, Japan, 4University Medical Center Utrecht, Netherlands, 5Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan

This study introduced a novel approach to differentiate hypointense nodules on gadoxetic acid-enhanced hepatobiliary phase images by use of a non-balanced spin-echo SSFP (T2FFE) sequence. T2FFE typically provides T2-weighted contrast, but theoretically has high sensitivity to T1 shortening effects due to gadoxetic acid. This approach might particularly be useful for distinguishing metastases and hemangiomas.

14:51 0140.   Liver R2* Dependence on Liver Storage Iron in Highly Iron Overloaded Patients: comparing 1.5 T to 3 T
Arthur Peter Wunderlich1, Steffen Klömpken1, Holger Cario2, Markus Juchems1, and Meinrad Beer1
1Dept. for Diagnostic and Interventional Radiology, Univ.-Clinic Ulm, Ulm, Germany, 2Pediatry, Univ.-Clinic Ulm, Ulm, Germany

The liver of iron overloaded patients was scanned with breathhold multicontrast GRE sequences at 1.5 T and 3 T. To address high liver iron content (LIC) resulting in high R2* values we used short echo spacing resulting in out-of-phase signal for fat and water. Therefore, liver fat fraction had to be included as free parameter for data fit. Four different flip angles lead to sufficient measurement data reliably above image noise at the cost of T1 as additional fit parameter. Data were fit to theory by Levenberg-Marquardt algorithm. Dependence of R2* on LIC was compared between field strengths.

15:03 0141.   
In-vivo evaluation of hepatic function using dynamic Gd-EOB-DTPA enhanced MRI with a dual-input one output two-compartment pharmacokinetics model
Jia Ning1, Sheng Xie2, Lei Wang2, Hua Guo1, Xihai Zhao1, Chun Yuan1,3, and Huijun Chen1
1Center for Biomedical Imaging Research & Department of Biomedical Engineering, Tsinghua University, Beijing, China, 2Department of Radiology, China-Japan Friendship Hospital, Beijing, China, 3Department of radiology, University of Washington, Seattle, WA, United States

Liver function is an important and sensitive indicator for liver damage. In this study, we proposed a new hemodynamic model to better describe the behavior of the Gd-EOB-DTPA by adding a directly measured contrast excretion term from hepatic vein. Validations with serum liver functional parameters were carried out for the proposed model and original model. Model parameters Ki is found significantly correlated with the concentration of preALB and ALB in serum. The proposed dual-input one output two-compartment pharmacokinetics model for dynamic Gd-EOB-DTPA enhanced liver MRI is capable of localized liver function evaluation in-vivo.fibrosis can envolve to cirrhosis and finally end up with hepatic carcinoma. Various studies have shown that fibrosis of level 1 and level 2 can be reversible [2], early diagnosis of liver fibrosis is critical for treatment and recovery. Dynamic contrast enhanced MR imaging is one of the most powerful protocols to evaluate the condition of liver. Gd-EOB-DTPA is a new type of hepatocyte specific contrast agent [3] for liver function evaluation. It has the advantages of specific binding with hepatocytes, and excretion through the hepatic vein, kidney and biliary. According to the properties of this contrast agent, we propose a new hemodynamics model to describe the perfusion of the liver. It is supposed that the parameters of the model can give an instruction of hepatic function and provide useful information for diagnosis of liver fibrosis.

15:15 0142.   
Gadoxetate-enhanced MRI in rats with liver cirrhosis: comparison between functional liver parameters obtained with deconvolution analysis and compartmental models as markers of hepatocyte transporter expression
Céline Giraudeau1, Jean-Luc Daire1, Matthieu Lagadec1, Sabrina Doblas1, Catherine Pastor2, and Bernard Van Beers1
1INSERM Centre de Recherche Biomédicale Bichat Beaujon,CRB3 U773, Université Paris Diderot, Sorbonne Paris Cité, Clichy, France, 2Laboratoire de Physiopathologie Hépatique et Imagerie Moléculaire,Hôpitaux Universitaires de Genève, Geneva, Switzerland

We have previously shown that the hepatic functional parameters (hepatic extraction fraction (HEF) and mean residence time (MRT)) obtained with deconvolution analysis at gadoxetate-enhanced MRI correlate with the expression of the oatp/mrp transporters in liver cirrhosis. The aim of this study was to assess if a multicompartmental model of hepatocytic transport gives further insight into the expression of the oatp/mrp transporters in liver cirrhosis. Both methods were evaluated in normal and cirrhotic rats through calculation of Akaike criteria and multiple regression analysis. The superiority of a multicompartmental relative to a deconvolution model remains here to be proven.

15:27 0143.   
R2* of water and fat in hepatic iron overload: implications for R2*-corrected fat quantification
Debra E. Horng1,2, Diego Hernando1, and Scott B. Reeder1,2
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, 2Medical Physics, University of Wisconsin-Madison, Madison, WI, United States

Accurate fat quantification using chemical shift-encoded techniques requires correction for R2* (=1/T2*) decay. Correction for a common R2* for both fat and water (“single-R2*”) has been shown to be accurate for FF quantification in patients without iron overload. In this work, the accuracy of single-R2* correction is assessed in patients with iron overload. Fat-fraction and R2* were measured in 42 subjects at 1.5T and 3.0T, with both imaging and spectroscopy. The R2* of fat and water are very similar even in the presence of iron overload, showing that fat quantification with single-R2* correction is accurate even for patients with iron overload.

15:39 0144.   Rician-noise based R2* Estimation for Severe Hepatic Iron Overload: Simulation, Phantom, and Early Clinical Experience
Takeshi Yokoo1,2, Qing Yuan1, Julien Senegas3, Andrea Wiethoff2,4, and Ivan M Pedrosa1,2
1Radiology, UT Southwestern Medical Center, Dallas, TX, United States, 2Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, United States, 3Philips Research Laboratories, Hamburg, Germany, 4Philips Research North America, Briarcliff Manor, NY, United States

Patients with severe hepatic iron overload are at risk for developing end-stage liver disease and in greatest need for therapy. An R2*-based measure has been proposed as a surrogate for liver iron, but its estimation is challenging in severe iron overload due to rapid signal decay. In this series of simulation, phantom, and human studies, we compared R2* estimation performance of several existing methods: linear least squares, nonlinear least squares (NLS), weighted NLS, NLS with constant noise offset, and Rician-noise based. Our results show that Rician-noise based method is clinically feasible and may be necessary to accurately estimate R2* for severe iron overload.

15:51 0145.   Poor Gadoxetate Disodium Hepatobiliary Enhancement in MRI of Patients with Cirrhosis: Factors for Prediction
Amelia Wnorowski1, Flavius Guglielmo1, Laurence Parker1, Sandeep Deshmukh1, Patrick O'Kane1, Christopher Roth1, and Donald Mitchell1
1Radiology, Thomas Jefferson University Hospital, Philadelphia, PA, United States

Gadoxetate disodium is a useful MRI contrast agent for the diagnosis of hepatocellular carcinoma in cirrhosis. Its use is limited by poor hepatic and biliary enhancement in some patients. The purpose of this study was to identify predictors of poor enhancement, which was assessed in 91 cirrhotic patients and compared to various laboratory parameters, liver length and degree of ascites. A correlation matrix was performed, followed by multiple and logistic regressions. Several variables independently correlated with enhancement. However, the first variable chosen, either albumin or MELD score, accounted for almost all of the variance in the model.

16:03 0146.   
Same Day 1.5T vs 3T Reproducibility of Liver Proton Density Fat Fractions in Obese Patients
Nathan Artz1, William Haufe2, Tanya Chavez2, Gavin Hamilton2, Michael Middleton2, Jeff Schwimmer3, Diego Hernando1, Ann Shimakawa4, Jonathan Hooker2, Claude Sirlin2, and Scott Reeder1,5
1Radiology, University of Wisconsin, Madison, WI, United States, 2Radiology, University of California, San Diego, CA, United States, 3Pediatrics, University of California, San Diego, CA, United States, 4Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, United States, 5Medicine, University of Wisconsin, Madison, WI, United States

The purpose of this work is to examine the 1.5T vs 3T reproducibility of hepatic proton density fat fraction (PDFF) measurements. Obese patients were scanned using three distinct quantitative MR techniques on the same day at both field strengths. Regression analysis was used to compare co-localized 1.5T and 3T PDFF measurements. All three techniques demonstrated very good agreement between 1.5T and 3T liver PDFF measurements, indicating that PDFF quantification is reproducible across field strengths.