TOMOYUKI OKUAKI¹, Kosuke Morita², Tomohiro Namimoto³, Morikatsu Yoshida³, Shinya Shiraishi³, Yasuyuki Yamashita³, and Marc Van Cauteren^1
1Philips Healthcare, Minato-ku, Tokyo, Japan, ²Department of Central Radiology, Kumamoto University Hospital, Kumamoto, Japan, ³Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan

The hepatocyte fraction(HeF) map is calculated from R1 maps acquired using a breathhold Look-Locker sequence pre and post Gd-EOB-DTPA. Further, the kHep value is calculated as uptake function. The resulting HeF and kHep were compared to the results of 99mTc-GSA scintigraphy. Seventy five patients were classified into four severity levels based on scintigraphy. The median values of the HeF of Normal, Mild, Moderate and Severe were 76.7%, 72.5%, 50.4% and 44.8% respectively. The HeF and kHep decreased with liver function deterioration. The HeF is useful for a robust evaluation of liver function and kHep provides information about hepatic uptake.

Benjamin Leporq¹, Sabine Schmidt², Catherine Pastor^1,3, Jean Luc Daire¹, and Bernard Edgar Van Beers^1,4
1Center of research on inflammation, Paris 7 University; INSERM U1044, Paris, France, ²Department of Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland, ³Laboratoire de Physiopathologie Hépatique et Imagerie Moléculaire, Hôpitaux Universitaires de Genève, Geneva, Switzerland,⁴Department of Radiology, Beaujon University hospital Paris Nord, Clichy, France

This study aims to evaluate the feasibility of quantifying simultaneously the liver perfusion and hepatocyte uptake function with dynamic gadoxetate-enhanced MR imaging in patients with chronic liver diseases. Dynamic imaging was performed and gadoxetate kinetics was modeled with a dual input dual compartment uptake model. Both increase of hepatic artery fraction of liver perfusion and decrease of hepatocyte gadoxetate uptake in patients with chronic liver diseases were observed. These results suggest that pharmacokinetic parameters at dynamic gadoxetate-enhanced MR imaging have the potential to become imaging biomarkers of both liver perfusion and hepatocyte function in patients with chronic liver diseases.

Yong Chen¹, Chaitra Badve¹, Shivani Pahwa¹, Mark Griswold^1,2, Nicole Seiberlich^1,2, and Vikas Gulani^1,2
1Department of Radiology, Case Western Reserve University, Cleveland, OH, United States, ²Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States

Perfusion quantification in liver is extremely challenging due to physiological motion and the need for large organ coverage. Recently, a non-Cartesian parallel imaging based technique for high resolution 3D liver perfusion imaging was introduced. Here, this technology was applied to image patients with focal liver lesions. Our results demonstrate significant differences in perfusion parameters between liver lesions and normal tissues, illustrating the possibility of quantitative lesion characterization using this technique.

Dan Zhu¹, Feng Huang², Jia Ning¹, Feiyu Chen¹, and Huijun Chen^1
1Tsinghua University, Beijing, Beijing, China, ²Philips Healthcare, Suzhou, Jiangsu, China

We proposed the reconstruction method of sparse radial k-t SPIRiT, which combines sparsity constraint into radial k-t SPIRiT for highly accelerated dynamic imaging with high spatiotemporal resolution. The efficiency of the proposed method was demonstrated by phantom and in-vivo liver data acquired with golden angle radial trajectory. The proposed method has higher SNR and less striking artifacts compared to SPIRiT and radial k-t SPIRiT reconstruction without sparsity constraint.

Genwen Hu^1,2, Xianyue Quan¹, Xiaoying Lin², Queenie Chan³, Yingjie Mei⁴, Xuhui Zhang¹, and Yufa Li^5
1Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China, ²Medical Image Center,Shenzhen Bao'an Maternal and Child Health Hospital, Shenzhen, Guangdong, China, ³Philips Healthcare, Hong Kong, China, ⁴Philips Healthcare, Guangzhou, Guandong, China,⁵Department of Pathology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong, China

The purpose of this study was to explore the characteristics of ADC and T1¦Ñ in various stages of liver fibrosis in CCl4-induced rats. ADC and T1¦Ñ MRI were performed with a 3.0T clinical scanner. Stages of liver fibrosis were evaluated using METAVIR scores (stage F0-stage F4) of liver serial sections stained with hematoxylin and eosin and Masson¡¯s trichrome. Nonparametric methods and receiver operating characteristic (ROC) curve analyses were used to determine diagnostic accuracy. ADC and T1¦Ñ showed significant correlations with stages of liver fibrosis in a rat model, where T1¦Ñ is regarded to be superior to ADC in distinguishing the stages.

Meng Yin¹, Ruisi Wang², Usman Yaqoob², Shennen A. Mao³, Jaime M. Glorioso³, Kevin J. Glaser¹, Liu Yang², Vijay Shah², Scott L. Nyberg³, and Richard L. Ehman^1
1Radiology, Mayo Clinic, Rochester, Minnesota, United States, ²Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, United States,³Transplatation Surgery, Mayo Clinic, Rochester, Minnesota, United States

To investigate the utility of MRE-derived mechanical properties in characterizing diseased hepatic tissue, we performed multifrequency 3-D/3-axis MRE on two mouse models with carbon tetrachloride (CCl4) induced chronic liver injury and one Fumarylacetoacetate hydrolase (FAH) deficient pig model with chronic liver disease. Liver stiffness, phase angle, storage and loss modulus frequency dispersions were selected for evaluation. Results demonstrated distinct and potentially characteristic changes in these mechanical properties with hepatic inflammation, fibrosis and increased portal pressure. The findings offer preliminary evidence of the potential to extend MRE to distinguish and independently assess necroinflammatory and fibrotic processes.

Alejandro Roldán-Alzate¹, Adnan Said², Camilo Campo¹, Kevin M Johnson³, Christopher J Francois¹, Oliver Wieben^1,3, and Scott B Reeder^1,3
1Radiology, University of Wisconsin - Madison, Madison, WI, United States, ²Hepatology, University of Wisconsin - Madison, Madison, WI, United States,³Medical Physics, University of Wisconsin - Madison, Madison, WI, United States

The purpose of this study was to evaluate 4D flow MRI as non-invasive method for characterizing and staging patients with portal hypertension. Nineteen patients with cirrhosis and suspected portal hypertension were studied. Significant increase in portal venous flow and no significant increase in azygos flow were seen in response to meal challenge. Good correlation was observed between baseline azygos flow and the Child-Pugh score as well as between portal venous shunt fraction at baseline and Child-Pugh score. The ability to non-invasively quantify hemodynamic changes not only in normal vessels but also in collateral circulation demonstrates that 4D flow MRI may be a suitable tool for staging and monitoring treatment of patients with portal hypertension.

Ying Gao¹, Bernadette O. Erokwu², David A. DeSantis³, Colleen M. Croniger³, Rebecca M. Schur¹, Lan Lu^2,4, Katherine M. Dell⁵, and Chris A. Flask^1,2
1Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, United States, ²Radiology, Case Western Reserve University, Cleveland, Ohio, United States, ³Nutrition, Case Western Reserve University, Cleveland, Ohio, United States, ⁴Urology, Case Western Reserve University, Cleveland, Ohio, United States, ⁵Pediatrics, Case Western Reserve University, Cleveland, Ohio, United States

ARPKD is a potentially lethal multi-organ disease characterized by both polycystic kidneys and congenital hepatic fibrosis (CHF). Unfortunately, there are currently no non-invasive methods to monitor CHF in ARPKD patients limiting the study of potential therapeutic interventions. Herein, we perform an initial investigation of liver perfusion measured by Arterial Spin Labeling (ASL) MRI. Longitudinal liver perfusion data were acquired from PCK rats at 2 months and 3 months of age using an ASL-FISP technique. Initial results suggest that liver perfusion as measured by ASL MRI may provide a sensitive and non-invasive imaging biomarker to safely monitor ARPKD liver disease progression.

Jin Wang^1,2, Meng Yin¹, Sudhakar Kundapur Venkatesh¹, and Richard L. Ehman^1
1Radiology, Mayo Clinic, Rochester, MN, United States, ²Radiology, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China

Autoimmune hepatitis (AIH) is a chronic liver disease of unknown etiology with a tendency to relapse and progress to cirrhosis. We assessed the diagnostic accuracy of 2D-MRE in predicting cirrhosis in biopsy-proven AIH with no prior treatment and in patients with AIH who already received treatment. Study results showed that MRE has excellent accuracy in detecting cirrhosis in AIH in both pretreatment and treatment groups. Preliminary study also showed that MRE is useful to assess treatment response in patients on treatment. MRE, therefore is a useful non-invasive technique for detection of cirrhosis in AIH and assessment of treatment response.

Peter Bannas^1,2, Harald Kramer³, Diego Hernando¹, Ashley M Cunningham⁴, Rakesh Mandal⁴, Rashmi Agni⁴, Utaroh Motosugi¹, Samir D Sharma¹, Alejandro Munoz del Rio¹, Luis Fernandez⁵, and Scott B Reeder^1,6
1Radiology, University of Wisconsin-Madison, Madison, WI, United States, ²Radiology, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, ³Radiology, Ludwig-Maximilians-University Hospital, Munich, Bavaria, Germany, ⁴Pathology, University of Wisconsin-Madison, Madison, WI, United States, ⁵Surgery, University of Wisconsin-Madison, Madison, WI, United States, ⁶Medical Physics, University of Wisconsin-Madison, Madison, WI, United States

The aim of our study was to validate MRI based estimation of proton density fat-fraction (PDFF) as an imaging biomarker of hepatic steatosis. Previous in vivo studies have compared MRI-PDFF with the current reference standard histology. However, in these studies the underlying triglyceride content remained unknown. In this work, we used ex vivo human livers to compare MRI-PDFF with histology, MR spectroscopy (MRS) and biochemical triglyceride extraction as three independent reference standards. Our results reveal a good correlation of MRI-PDFF with hepatic triglyceride concentration, MRS and histological analysis, validating that MRI-based PDFF is an accurate biomarker of hepatic steatosis.