Hepatocarcinogenesis: Radiology-Pathology Correlation
In the background of chronic liver disease, hepatocellular carcinoma develops via a complex, multistep process called hepatocarcinogenesis. This article reviews the causes contributing to the process. Emphasis is made on the imaging manifestations of the pathologic changes seen at many stages of hepatocarcinogenesis, from regenerative nodules to dysplastic nodules and then to hepatocellular carcinoma.
Proliferative versus Nonproliferative Hepatocellular Carcinoma: Clinical and Imaging Implications [Comment]
Cholangiopathy After Severe COVID-19: Clinical Features and Prognostic Implications
INTRODUCTION/BACKGROUND:Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 virus, is a predominantly respiratory tract infection with the capacity to affect multiple organ systems. Abnormal liver tests, mainly transaminase elevations, have been reported in hospitalized patients. We describe a syndrome of cholangiopathy in patients recovering from severe COVID-19 characterized by marked elevation in serum alkaline phosphatase (ALP) accompanied by evidence of bile duct injury on imaging. METHODS:We conducted a retrospective study of COVID-19 patients admitted to our institution from March 1, 2020, to August 15, 2020, on whom the hepatology service was consulted for abnormal liver tests. Bile duct injury was identified by abnormal liver tests with serum ALP > 3x upper limit of normal and abnormal findings on magnetic resonance cholangiopacreatography. Clinical, laboratory, radiological, and histological findings were recorded in a Research Electronic Data Capture database. RESULTS:Twelve patients were identified, 11 men and 1 woman, with a mean age of 58 years. Mean time from COVID-19 diagnosis to diagnosis of cholangiopathy was 118 days. Peak median serum alanine aminotransferase was 661 U/L and peak median serum ALP was 1855 U/L. Marked elevations of erythrocyte sedimentation rate, C-reactive protein, and D-dimers were common. Magnetic resonance cholangiopacreatography findings included beading of intrahepatic ducts (11/12, 92%), bile duct wall thickening with enhancement (7/12, 58%), and peribiliary diffusion high signal (10/12, 83%). Liver biopsy in 4 patients showed acute and/or chronic large duct obstruction without clear bile duct loss. Progressive biliary tract damage has been demonstrated radiographically. Five patients were referred for consideration of liver transplantation after experiencing persistent jaundice, hepatic insufficiency, and/or recurrent bacterial cholangitis. One patient underwent successful living donor liver transplantation. DISCUSSION/CONCLUSIONS:Cholangiopathy is a late complication of severe COVID-19 with the potential for progressive biliary injury and liver failure. Further studies are required to understand pathogenesis, natural history, and therapeutic interventions.
Accelerated single-shot T2-weighted fat-suppressed (FS) MRI of the liver with deep learning-based image reconstruction: qualitative and quantitative comparison of image quality with conventional T2-weighted FS sequence
OBJECTIVE:To compare the image quality of an accelerated single-shot T2-weighted fat-suppressed (FS) MRI of the liver with deep learning-based image reconstruction (DL HASTE-FS) with conventional T2-weighted FS sequence (conventional T2 FS) at 1.5 T. METHODS:One hundred consecutive patients who underwent clinical MRI of the liver at 1.5 T including the conventional T2-weighted fat-suppressed sequence (T2 FS) and accelerated single-shot T2-weighted MRI of the liver with deep learning-based image reconstruction (DL HASTE-FS) were included. Images were reviewed independently by three blinded observers who used a 5-point confidence scale for multiple measures regarding the artifacts and image quality. Descriptive statistics and McNemar's test were used to compare image quality scores and percentage of lesions detected by each sequence, respectively. Intra-class correlation coefficient (ICC) was used to assess consistency in reader scores. RESULTS:Acquisition time for DL HASTE-FS was 51.23 +/ 10.1 s, significantly (p < 0.001) shorter than conventional T2-FS (178.9 Â± 85.3 s). DL HASTE-FS received significantly higher scores than conventional T2-FS for strength and homogeneity of fat suppression; sharpness of liver margin; sharpness of intra-hepatic vessel margin; in-plane and through-plane respiratory motion; other ghosting artefacts; liver-fat contrast; and overall image quality (all, p < 0.0001). DL HASTE-FS also received higher scores for lesion conspicuity and sharpness of lesion margin (all, p < .001), without significant difference for liver lesion contrast (p > 0.05). CONCLUSIONS:Accelerated single-shot T2-weighted MRI of the liver with deep learning-based image reconstruction showed superior image quality compared to the conventional T2-weighted fat-suppressed sequence despite a 4-fold reduction in acquisition time. KEY POINTS/CONCLUSIONS:â€¢ Conventional fat-suppressed T2-weighted sequence (conventional T2 FS) can take unacceptably long to acquire and is the most commonly repeated sequence in liver MRI due to motion. â€¢ DL HASTE-FS demonstrated superior image quality, improved respiratory motion and other ghosting artefacts, and increased lesion conspicuity with comparable liver-to-lesion contrast compared to conventional T2FS sequence. â€¢ DL HASTE- FS has the potential to replace conventional T2 FS sequence in routine clinical MRI of the liver, reducing the scan time, and improving the image quality.
Hereditary ovarian tumour syndromes: current update on genetics and imaging
Hereditary ovarian tumour syndromes are a diverse group of hereditary syndromes characterised by the development of specific histotypes of ovarian neoplasms. While BRCA syndromes are exclusively associated with high-grade serous carcinomas, patients with Lynch syndrome show a preponderance of endometrioid subtype of ovarian and endometrial carcinomas. Distinct non-epithelial phenotypes, such as sex cord stromal tumours with annular tubules, Sertoli-Leydig cell tumours, and small cell carcinoma of the hypercalcaemic type occur in patients with Peutz-Jeghers, DICER1, and rhabdoid tumour predisposition syndromes, respectively. Gorlin-Goltz syndrome is characterised by the development of bilateral, multiple ovarian fibromas in 14-24% of patients. Ovarian steroid cell tumours and broad ligament papillary cystadenomas are characteristically found in women with von Hippel-Lindau syndrome. Recent studies have allowed the characterisation of tumour genetics and associated oncological pathways that contribute to tumourigenesis. Implications of the diagnosis of these syndromes on screening, management, and prognosis are discussed.
Noninvasive Staging of Liver Fibrosis with Dual-Energy CT: Close but No Cigar [Comment]
The humbling hemangioma: uncommon CT and MRI imaging features and mimickers of hepatic hemangiomas
Cavernous hemangiomas are among the most common liver lesions encountered in abdominal imaging. While classical imaging characteristics usually aid the radiologist in confidently arriving at its diagnosis, atypical hemangiomas can prove to be difficult to distinguish from other more worrisome hepatic lesions such as metastases and hepatocellular carcinoma. Furthermore, some malignant lesions can display features that simulate hemangiomas. The radiologist must be aware of these pitfalls to make an accurate diagnosis, when possible.
Expert radiologist review at a hepatobiliary multidisciplinary tumor board: impact on patient management
PURPOSE/OBJECTIVE:To identify the frequency, source, and management impact of discrepancies between the initial radiology report and expert reinterpretation occurring in the context of a hepatobiliary multidisciplinary tumor board (MTB). METHODS:This retrospective study included 974 consecutive patients discussed at a weekly MTB at a large tertiary care academic medical center over a 2-year period. A single radiologist with dedicated hepatobiliary imaging expertise attended all conferences to review and discuss the relevant liver imaging and rated the concordance between original and re-reads based on RADPEER scoring criteria. Impact on management was based on the conference discussion and reflected changes in follow-up imaging, recommendations for biopsy/surgery, or liver transplant eligibility. RESULTS:Image reinterpretation was discordant with the initial report in 19.9% (194/974) of cases (59.8%, 34.5%, 5.7% RADPEER 2/3/4 discrepancies, respectively). A change in LI-RADS category occurred in 59.8% of discrepancies. Most common causes of discordance included re-classification of a lesion as benign rather than malignant (16.0%) and missed tumor recurrence (13.9%). Impact on management occurred in 99.0% of discordant cases and included loco-regional therapy instead of follow-up imaging (19.1%), follow-up imaging instead of treatment (17.5%), and avoidance of biopsy (12.4%). 11.3% received OPTN exception scores due to the revised interpretation, and 8.8% were excluded from listing for orthotopic liver transplant. CONCLUSION/CONCLUSIONS:Even in a sub-specialized abdominal imaging academic practice, expert radiologist review in the MTB setting identified discordant interpretations and impacted management in a substantial fraction of patients, potentially impacting transplant allocation. The findings may impact how abdominal imaging sections best staff advanced MTBs.
Response assessment of hepatocellular carcinoma treated with yttrium-90 radioembolization: inter-reader variability, comparison with 3D quantitative approach, and role in the prediction of clinical outcomes
OBJECTIVES/OBJECTIVE:To assess the inter-reader variability in response assessment for HCC treated with radioembolization (TARE) compared with 3D quantitative criteria (qEASL); and to evaluate their role in prediction of pathological necrosis and clinical outcomes. MATERIALS AND METHODS/METHODS:57 patients with 77 HCCs who underwent TARE were included. Five radiologists recorded multiple imaging features and assigned mRECIST/LIRADS Treatment Response (TR) categories on post-treatment MRI at 4-6 weeks and 6-9 months after TARE. qEASL categories were assigned by a separate reader. Inter-reader variability between LIRADS TR/mRECIST/qEASL were evaluated and hazards regression was used in predicting clinical outcomes. RESULTS:Inter-reader agreement was fair for mRECIST (Kâ€¯=â€¯0.43 and 0.34 at first and second follow-up respectively); moderate for LIRADS TR (Kâ€¯=â€¯0.48 and 0.53 at first and second follow-up respectively). Inter-criterion agreement was moderate to substantial (râ€¯=â€¯0.41-0.65 and râ€¯=â€¯0.54-0.60 at first and second follow-up) for mRECIST-qEASL. LIRADS TR correlated well with qEASL for all readers at both follow-ups (Kâ€¯=â€¯0.45-0.78; Kâ€¯=â€¯0.39-0.77 for first and second follow-up). qEASL was the most accurate in predicting Tumor-Free Survival (TFS) on first (HR 2.23 [1.44-3.46], pâ€¯<â€¯0.001) and second (HR 1.69 [1.15-2.48], pâ€¯=â€¯0.008) follow-up. LIRADS TR was the most accurate in predicting histopathological necrosis (8 patients underwent liver transplantation and 1 patient underwent tumor resection during the period of the study). CONCLUSIONS:HCC response assessment following TARE is challenging, resulting in poor to moderate inter-reader agreement for mRECIST, and moderate inter-reader agreement for LIRADS TR response assessment criteria. qEASL outperformed mRECIST criteria for early identification of responders and predicting TFS, suggesting an advantage in volumetric tumor response assessment. LIRADS TR outperformed other criteria in predicting pathological necrosis.
MR elastography, T1 and T2 relaxometry of liver: role in noninvasive assessment of liver function and portal hypertension
PURPOSE/OBJECTIVE:To evaluate the correlation between liver stiffness as measured on MR elastography and T1 and T2 relaxation times from T1 and T2 mapping with clinical parameters of liver disease, including the MELD score, MELD-Na and ALBI grade, and endoscopically visible esophageal varices. MATERIALS AND METHODS/METHODS:223 patients with known or suspected liver disease underwent MRI of the liver with T1 mapping (Look-Locker sequence) and 2D SE-EPI MR elastography (MRE) sequences. 139 of these patients also underwent T2 mapping with radial T2 FS sequence. Two readers measured liver stiffness, T1 relaxation times and T2 relaxation times, and assessed qualitative features such as presence or absence of cirrhosis, ascites, spleen length, and varices on conventional MRI images. A third reader collected the clinical data (MELD score, MELD-Na Score, ALBI grade, and results of endoscopy in 78 patients). RESULTS:Significant moderate correlation was found between MELD score and all three imaging techniques for both readers (MRE, râ€‰=â€‰0.35 and 0.28; T1 relaxometry, râ€‰=â€‰0.30 and 0.29; T2 relaxometry, râ€‰=â€‰0.45, and 0.37 for reader 1 and reader 2 respectively). Correlation with MELD-Na score was even higher (MRE, râ€‰=â€‰0.49 and 0.40; T1, râ€‰=â€‰0.45 and 0.41; T2, râ€‰=â€‰0.47 and 0.35 for reader 1 and reader 2 respectively). Correlations between MRE and ALBI grade was significant and moderate for both readers: râ€‰=â€‰0.39 and 0.37, higher than T1 relaxometry (râ€‰=â€‰0.22 and 0.20) and T2 relaxometry (râ€‰=â€‰0.17, and râ€‰=â€‰0.24). Significant moderate correlations were found for both readers between MRE and the presence of varices on endoscopy (râ€‰=â€‰0.28 and 0.30). MRE and T1 relaxometry were significant predictors of varices at endoscopy for both readers (MRE AUC 0.923 and 0.873; T1 relaxometry AUCâ€‰=â€‰0.711 and 0.675 for reader 1 and reader 2 respectively). Cirrhotic morphology (AUCâ€‰=â€‰0.654), spleen length (AUCâ€‰=â€‰0.610) and presence of varices in the upper abdomen on MRI (AUC of 0.693 and 0.595) were all significant predictors of endoscopic varices. Multivariable logistic regression model identified that spleen length and liver MRE were significant independent predictors of endoscopic varices for both readers. CONCLUSION/CONCLUSIONS:MR elastography, T1 and T2 relaxometry demonstrated moderate positive correlation with the MELD score and MELD-Na Score. Correlation between MRE and ALBI grade was superior to T1 and T2 relaxometry methods. MRE performed better than T1 and T2 relaxometry to predict the presence of varices at endoscopy. On multivariate analyses, spleen length and MRE were the only two significant independent predictors of endoscopic varices.