Xin Lu¹, Jiahui Li¹, Zheng Zhu¹, Alina Allen², Taofic Mounajjed³, Kevin J Glaser¹, Jinhang Gao ⁴, Jingbiao Chen¹, Jie Chen¹, Safa Hoodeshenas¹, Armando Manduca¹, Richard L Ehman¹, and Meng Yin^1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States, ²Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, United States, ³Anatomic Pathology, Mayo Clinic, Rochester, MN, United States, ⁴Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, United States

NASH is traditionally diagnosed by liver biopsy,  limited by subjective scoring and sampling error. This motivates identifying imaging-based biomarkers that might quantitatively characterize the pathophysiologic features of NASH. This prospective study established a streamlined imaging protocol for acquiring three candidate biomarkers ( fat fraction, liver stiffness, and T1 ) in a cohort of 66 patients with suspected NASH who underwent biopsy.  The results indicate that a two-parameter model using fat fraction and liver stiffness has superior accuracy in diagnosing NASH, including ones that include the T1 relaxation time, which was found to have high collinearity with the fat fraction.

Marian A. Troelstra¹, Julia J. Witjes², Anne-Marieke van Dijk², Anne Linde Mak², Jurgen H. Runge¹, Joanne Verheij³, Max Nieuwdorp², Adriaan G. Holleboom², Aart J. Nederveen¹, and Oliver J. Gurney-Champion^1
1Department of Radiology and Nuclear Medicine, Amsterdam UMC, location AMC, Amsterdam, Netherlands, ²Department of Internal and Vascular Medicine, Amsterdam UMC, location AMC, Amsterdam, Netherlands, ³Department of Pathology, Amsterdam UMC, location AMC, Amsterdam, Netherlands

In this study we have developed an unsupervised physics-informed deep neural network (IVIM₃-NET) to fit a tri-exponential model to intravoxel incoherent motion (IVIM) data from 35 non-alcoholic fatty liver disease (NAFLD) patients. Diagnostic performance was compared to a tri-exponential least squares (LSQ) fit. Visually, IVIM₃-NET showed high-quality parameter maps with less noise than the LSQ-fit. IVIM₃-NET showed slightly higher correlations between fit parameters and histology and more significant differences between levels of fibrosis and inflammation than the LSQ-fit. Correlations between f₂ and fibrosis and inflammation grade, potentially highlighting NAFLD-induced vascular changes, warrant further investigation of the IVIM₃-NET in NAFLD patients.

Safa Hoodeshenas¹, Mahmoud Adam Tahboub Amawi², Jingbiao Chen^1,3, Nimish Thakral², Kevin J. Glaser¹, Bogdan Dzyubak¹, Jiahui Li¹, Xin Lu¹, Jie Chen¹, Zheng Zhu¹, Patrick S. Kamath², Vijay Shah², Richard L. Ehman¹, Sudhakar K. Venkatesh¹, Douglas A. Simonetto², and Meng Yin^1
1Department of Radiology, Mayo Clinic, Rochester, MN, United States, ²Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, United States, ³The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China

In patients with end-stage chronic liver diseases, esophageal varices can be a life-threatening complication of portal hypertension because of bleeding risk. In this study, we explored the role of MR elastography (MRE) in stratifying portal hypertension severity and predicting high-risk varices by using upper gastrointestinal endoscopy as the reference standard. We concluded that a composite model including spleen size and stiffness plus liver stiffness and platelet count more accurately predicts the presence of high-risk varices, and thus could reduce unnecessary endoscopies more precisely than using liver stiffness and platelet count alone.

Jian Hou¹, Vincent Wai-Sun Wong², Grace Lai-Hung Wong², Baiyan Jiang¹, Yi-Xiang Wang¹, Anthony Wing-Hung Chan³, Winnie Chiu-Wing Chu¹, and Weitian Chen^1
1Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Hong Kong, Hong Kong, ²Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Hong Kong, Hong Kong, ³Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong, Hong Kong

Liver fibrosis is characterized by excessive accumulation of extracellular matrix proteins, such as collagen. Macromolecular Proton Fraction (MPF) is an indicator of the relative amount of macromolecular content. It was reported recently that MPF map can be obtained based on spin-lock (MPF-SL). In this work, we investigated the diagnostic value of MPF-SL for detecting early stage liver fibrosis on a clinical study.

Fasil Gadjimuradov^1,2, Thomas Benkert², Marcel Dominik Nickel², and Andreas Maier^1
1Pattern Recognition Lab, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany, ²Magnetic Resonance, Siemens Healthcare GmbH, Erlangen, Germany

Partial Fourier (PF) acquisition allows to reduce TE in single-shot echo-planar imaging in order to increase signal-to-noise ratio (SNR) in diffusion-weighted imaging (DWI). However, when applying it to motion-prone liver DWI, conventional PF reconstruction methods fail since they rely on smoothness priors of the phase. This work proposes to use an unrolled network architecture which aims to estimate a more appropriate regularization by learned recurrent convolutions. It can be shown that reconstructions produced by the network are superior in terms of quantitative measures as well as qualitative impression compared to conventional methods which tend to introduce artifacts.

lu wang¹, Tian Li², Jing Cai², and Hing-Chiu Chang^1
1Department of Diagnostic Radiology, The University of Hong Kong, HongKong, China, ²Department of Health Technology and Informatics, The Hong Kong Polytechnic University, HongKong, China

Motion-resolved four dimensional diffusion-weighted echo-planar imaging (4D-DW-EPI) may better characterize the respiratory-induced motion of tumor than 4D-MRI with conventional T1 and T2 image contrasts. However, the existing 4D-DW-EPI technique can only provide limited geometric accuracy and low sampling rate over respiratory cycles. Thus, we proposed an advanced 4D-DW-Propeller-EPI technique with golden angle acquisition for improving the geometric accuracy and data sampling rate. Simulation study and in-vivo study were conducted to evaluate the performance of 4D-DW-Propeller-EPI. Our results demonstrate that 4D-DW-Propeller-EPI showed superior image quality to 4D-DW-EPI and had a potential for the application of MRI-guided abdominal radiotherapy.

Hiroshi Hamano¹, Masami Yoneyama¹, Akihiro Nishie², Keisuke Ishimatsu², Chiaki Tokunaga³, Hiroaki Watanuki³, Tatsuhiro Wada³, Isao Shiina⁴, Michinobu Nagao⁵, Yasuhiro Goto⁴, Kazuo Kodaira⁴, Yutaka Hamatani⁴, Takumi Ogawa⁴, Takashi Namiki¹, and Kenji Iinuma^1
1Philips Japan, Tokyo, Japan, ²Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan, ³Division of Radiology, Department of Medical Technology, Kyushu University Hospital, Fukuoka, Japan, ⁴Department of Radiological Services, Tokyo Women’s Medical University, Tokyo, Japan, ⁵Department of Diagnostic Imaging and Nuclear Medicine, Tokyo Women’s Medical University, Tokyo, Japan

In the Liver DWI, the respiratory and cardiac motion induce signal loss and artificially increase ADC of the left hepatic lobe. On the other hand, Motion-Sensitive (MoSe) CINE imaging, based on T2FFE (also known as PSIF) sequence, could directly visualize the motion-insensitive cardiac timing thanks to that of motion sensitivity. We assumed that it is useful for determining optimal cardiac trigger delay (TD) in the liver DWI. We demonstrated that the respiratory and cardiac trigged DWI with optimal cardiac TD using MoSe CINE imaging leads to the robustness of image quality in DWI and ADC of the left hepatic lobe.

Hing-Chiu Chang¹, Lu Wang¹, Guangtao Chen¹, Liyuan Liang¹, Keith Wan-Hang Chiu¹, Yi-Jui Liu², Chun-Jung Juan^3,4,5, and Hsiao-Wen Chung^6,7
1Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, Hong Kong, ²Department of Automatic Control Engineering, Feng Chia University, Taichung, Taiwan, ³Department of Medical Imaging, China Medical University Hsinchu Hospital, Hsinchu, Taiwan, ⁴Department of Radiology, School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan, ⁵Department of Medical Imaging, China Medical University Hospital, Taichung, Taiwan, ⁶Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, ⁷Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan

The current limitations of liver DWI mainly relate to the image quality and the repeatability/reproducibility of ADC measurement using single-shot DW echo-planar imaging (DW-EPI). The discrepancy of ADC measurement can substantially cause difficulty in cross-sectional or longitudinal liver DW-EPI. A preliminary study reported that a free-breathing liver DW-Propeller-EPI technique can provide superior image quality to conventional liver DW-EPI methods. In this study, we further improved the robustness of free-breathing liver DW-Propeller-EPI by incorporating velocity-compensation (VC) diffusion gradient into data acquisition, and then evaluated the repeatability of liver ADC measurement for free-breathing DW-Propeller-EPI by comparing to three routine liver DW-EPI methods.

Philip Meng-en Lee¹, Jeremy W Gordon¹, Zhen J Wang¹, Zihan Zhu¹, Hsin-Yu Chen¹, Pamela N Munster², Rahul Aggarwal², Daniel B Vigneron¹, and Michael A Ohliger^1
1Department of Radiology & Biomedical Imaging, University of California, San Francisco, San Francisco, CA, United States, ²Department of Medicine, University of California, San Francisco, San Francisco, CA, United States

Analysis of the delivery and metabolism of hyperpolarized ¹³C pyruvate within the liver is complicated by the organ’s unique dual blood supply. Distinguishing the hepatic arterial and portal venous contributions of pyruvate delivery would improve real-time acquisition triggering and kinetic modeling. Three healthy subjects and two metastatic cancer subjects underwent hyperpolarized ¹³C MRI on a clinical 3 T MR scanner. We observed differential arrival of [1-¹³C]pyruvate signal in the aorta, inferior vena cava, portal vein, healthy liver, and metastases matching physiologic expectations. Consistencies were observed within subject groups, which is crucial for accurate timing and modelling of metabolic hyperpolarized signals.

Shintaro Ichikawa¹, Utaroh Motosugi², Tetsuya Wakayama³, Satoshi Funayama¹, Daiki Tamada¹, Sagar Mandava⁴, Ty A Cashen⁵, and Hiroshi Onishi^1
1Department of Radiology, University of Yamanashi, Chuo, Japan, ²Kofu Kyoritsu Hospital, Kofu, Japan, ³GE Healthcare, Hino, Japan, ⁴GE Healthcare, Atlanta, GA, United States, ⁵GE Healthcare, Madison, WI, United States

We performed intra-individual comparison of arterial phase (AP) images between differential subsampling with Cartesian ordering (DISCO) and stack-of-stars acquisition without breath-holding (DISCO-Star) on dynamic magnetic resonance imaging of the liver. Patients showing inadequate scan timing of AP in DISCO and DISCO-Star (12 s/phase) dataset were 4.9% and 21.2%, respectively. One advantage of DISCO-Star was that the adequate scan timing of AP can be obtained by using additional high frame rate reconstruction (3 s/phase) in the patient with inadequate scan timing in routine reconstruction. DISCO-Star was useful to obtain adequate AP imaging in all patients.