What’s new in Liver Imaging – August 2020

2 years ago

Hepatocellular Carcinoma

CT and MRI Liver Imaging Reporting and Data System Version 2018 for Hepatocellular Carcinoma: A Systematic Review With Meta-Analysis

Lee S, Kim Y-Y, Shin J, et al. J Am Coll Radiol [Internet]. Elsevier; 2020 [cited 2020];0.

Available from: https://linkinghub.elsevier.com/retrieve/pii/S154614402030644X

Keywords: LI-RADS, diagnostic value, CT, MRI, HCC

Clinical question: How well does LI-RADS detect HCC?

What was done: The LI-RADS v2018 was assessed for diagnostic performance of HCC detection within each LI-RADS category (LR1, LR2, LR3, LR4, LR5) on CT and MRI.

How was it done: Retrospective database review of MEDLINE, Embase, and Scopus for studies reporting the diagnostic accuracy of LI-RADS v2018 for HCC. Meta-analysis of 14 studies was done.

Findings and results: 2709 total observations with 1841 total HCCs. LR-5 had a 70% sensitivity and 91% specificity. No HCCs in LR1, no HCCs in LR2, 31% HCCs of LR3, 64% HCCs of LR4, 95% HCCs of LR5, 54% of LR-TIV, and 33% of LRM.

Conclusion: Increased LR category corresponded with increased proportion of HCC. The LR5 category of LI-RADS v2018 has moderate sensitivity and high specificity for HCC.

Implications: Using LI-RADS v2018 for hepatic observations has good performance, but has room for improvement.

 

LI-RADS 4 or 5 categorization may not be clinically relevant for decision-making processes: a prospective cohort study

Pinero F, Thompson MA, Telli FD, et al. Annals of Hepatology [Internet]. Elsevier; 2020 [cited 2020];0.

Available from: https://www.sciencedirect.com/science/article/pii/S1665268120300685?via%3Dihub

Keywords: LI-RADS, diagnostic value, CT, MRI, HCC

Clinical question: What is the clinical utility of LI-RADS in Latin America?

What was done: LI-RADS categories were compared with histopathology findings in liver transplant explants in a single center from Argentina.

How was it done: Prospective study between 2012-2018 of 130 patients with HCC listed for liver transplant. The LI-RADS categories from the major nodule (NOD1) on CT or MRI were compared with explant pathology findings.

Findings and results: Among the patients with LR-3 NOD1, 50% had HCC. Among LR-4 NOD1, 89% had HCC, of which 11% had microvascular invasion. Finally, among LR-5 NOD1, 77% had HCC, of which 17% had microvascular invasion.

Conclusion: No significant differences were observed between LR-4 and LR-5 in the probability of HCC when compared with explant pathology. Overall, LI-RADS was useful.

Implications: While most published LI-RADS studies show increased proportion of HCC with higher LR category, per the meta-analysis done by Lee et al in this past month, this was not the case when studying transplant patients in the single center for Argentina. Therefore, LR-4 must be treated seriously given this possible ambiguity between LR-4 and LR-5, depending on the patient population.

 

Pediatric Hepatoblastoma, Hepatocellular Carcinoma, and Other Hepatic Neoplasms: Consensus Imaging Recommendations from American College of Radiology Pediatric Liver Reporting and Data System (LI-RADS) Working Group

Schooler GR, Squires JH, Alazraki A, et al. Radiology [Internet]. Radiological Society of North America ; 2020 [cited 2020];200751.

Available from: http://pubs.rsna.org/doi/10.1148/radiol.2020200751

Keywords: MRI, HCC, CEUS, CT, diagnostic value

Clinical question: How can we standardize liver imaging for pediatric patients with suspected liver neoplasms?

What was done: A Pediatric Working Group within the ACR LI-RADS group was created and developed a consensus on imaging recommendations and guidance of how to interpret and report on imaging findings of pediatric liver lesions.

How was it done: 11 pediatric radiologists with subspecialized expertise in liver imaging came to a consensus regarding the recommendations shown in this article by way of a systematic, standardized scoring system.

Findings and results: Recommendations regarding when to use contrast-enhanced ultrasound (CEUS), when to use MRI, which MRI protocol to use, when to use CT, and the role of biopsy were all agreed upon and provided in this article.

Conclusion: A set of guidelines and recommendations for the imaging of pediatric patients with suspected hepatoblastoma or hepatocellular carcinoma are now available, put together by this subspecialized section of the ACR LI-RADS group.

Implications: When a pediatric patient has a suspected hepatocellular carcinoma or hepatoblastoma, it will be helpful to refer to these guidelines to ensure correct diagnostic steps are taken.

 

LIVER IMAGING TECHNIQUES

 

Radiographics Update: Contrast-enhanced US approach to the diagnosis of focal liver masses

Burrowes DP, Medellin A, Harris AC, et al. Radiographics [Internet]. Radiological Society of North America; 2017 [cited 2020];37:1388–1400.

Available from: https://pubs.rsna.org/doi/10.1148/rg.2020200109

Keywords: CEUS, diagnostic value, LI-RADS

Clinical question: How to build an algorithm toward evaluation of all liver nodules in adult patients, based on LI-RADS for CEUS in 2017?

What was done: Burrowes et al describe how the enhancement characteristics of HCC and precursor nodules can vary, based on how blood supply may change throughout the process of hepatocarcinogenesis. They correlate imaging findings of each type of nodule with their CEUS LI-RADS categories. This was done to update the previous algorithm published by Burrowes et al in 2017, which only addresses how to differentiate malignancy from non-malignancy.

Implications: CEUS LI-RADS can be used to categorize all hepatic observations in patients at risk for HCC, and furthermore can incorporate precursor nodules.

 

Contrast-Enhanced Ultrasound Liver Imaging Reporting and Data System in Diagnosing Hepatocellular Carcinoma: Diagnostic Performance and Interobserver Agreement

Zhou H, Zhang C, Du L, et al. Ultraschall Med. 2020 Jul 8. doi:10.1055/a-1168-6321.

Available from: https://pubmed.ncbi.nlm.nih.gov/32643777/

Keywords: CEUS, diagnostic value, LI-RADS

Clinical question: How reliable is the contrast-enhanced ultrasound liver imaging reporting and data system (CEUS-LI-RADS)?

What was done: The LI-RADS category assigned based on CEUS features was compared against the 2017 China Liver Cancer Guidelines (CLCG) of diagnosis of HCC.

How was it done: Prospective study of 96 high-risk patients with 96 histology-proven lesions underwent CEUS and the CEUS features were reported. Then, six blinded readers assigned a CEUS-LI-RADS category and the diagnostic performance of LR5 and multi-reader agreement were calculated.

Findings and results: LR5 had a sensitivity of 39-64%, accuracy of 53-71%, and specificity of 93-100%. Meanwhile, CLCG had a higher sensitivity of 89-100%, accuracy of 78-86%, but  much lower specificity of 29-64%. There was fair to moderate inter-reader agreement for CEUS-LI-RADS.

Conclusion: CEUS-LI-RADS category 5 has a high specificity but low accuracy for diagnosis of HCC in high-risk patients. Moreover, inter-reader agreement is not satisfactory concerning CEUS-LI-RADS.

Implications: Because the inter-reader agreement is not high for CEUS-LI-RADS, this may lead to decreased accuracy and sensitivity for HCC.

 

Contrast-Enhanced Ultrasound Algorithms (CEUS-LIRADS/ESCULAP) for the Noninvasive Diagnosis of Hepatocellular Carcinoma – A Prospective Multicenter DEGUM Study

Schellhaas B, Bernatik T, Bohle W, et al. Ultraschall Med. 2020 Jul 14. doi: 10.1055/a-1198-4874. Online ahead of print. PMID: 32663881 Clinical Trial. English.

Available from: https://pubmed.ncbi.nlm.nih.gov/32663881/

Keywords: CEUS, diagnostic value, LI-RADS

Clinical question: How accurate is contrast-enhanced ultrasound (CEUS) for noninvasive diagnosis of HCC in high-risk patients?

What was done: Conventional on-site CEUS interpretation, CEUS Erlanger Synopsis for CEUS Liver Lesion Assessment in Patients at risk (ESCULAP), and CEUS-LI-RADS were compared for the diagnostic accuracy of HCC.

How was it done: Prospective study of 321 patients recruited across 43 centers, all high-risk for HCC with histologically-proven focal liver lesion on B-mode ultrasound.

Findings and results: Among the 93% of patients who had cirrhosis, CEUS ESCULAP and on-site CEUS had the highest sensitivity of 94% and 91%, while CEUS-LI-RADS had the lowest sensitivity with 64%. However, CEUS-LI-RADS had a specificity of 79% while ESCULAP had the lowest specificity of 51%, and on-site CEUS in between at 65%. CEUS-LI-RADS had the lowest NPV of 34% while on-site CEUS and CEUS ESCULAP had NPV 63-67%. The PPV of all modalities was high around 90%.

Conclusion: CEUS is overall accurate for the noninvasive diagnosis of HCC, but the diagnostic accuracy of on-site CEUS is almost equivalent to the LI-RADS and ESCULAP algorithms.

Implications: It may not be necessary for experienced examiners with CEUS to use the LI-RADS or ESCULAP algorithms to augment the diagnostic accuracy of CEUS for HCC.

 

LIVER: BASIC SCIENCE

 

Advanced MRI of Liver Fibrosis and Treatment Response in a Rat Model of Nonalcoholic Steatohepatitis

Zhou IY, Clavijo Jordan V, Rotile NJ, et al. Radiology [Internet]. Radiological Society of North America (RSNA); 2020 [cited 2020];192118.

Available from: https://pubs.rsna.org/doi/abs/10.1148/radiol.2020192118

Keywords: MRI, imaging probes, fibrosis, NASH

Clinical question: Currently, liver biopsy is the standard for diagnosing NASH. How accurately can we characterize fibrosis and treatment response for NASH with noninvasive imaging?

What was done: Rat models with controlled dietary and treatment environments modeled different stages of NASH disease and response to treatment. They were used prospectively for imaging and histological analysis that was then used to build models of the predictive value for advanced MRI techniques.

How was it done: Prospective study of 66 rat models that were divided into 6 groups with different diets and treatments. A protocol was built to combine four methods of noninvasive MRI imaging utilizing the elastography sequence, T1 sequence, and two molecular-targeted MRI probes: a collagen-specific probe (EP-3533) and an allysine-targeted fibrogenesis probe (Gd-Hyd). ROI analysis was performed of the entire liver for each rat model and compared with histological results after harvesting the liver tissue by building ROC analysis curves.

Findings and results: Pathology results from each of the rat model groups showed desired results of multiple stages of fibrosis, steatosis, and treatment response. ROC analysis showed collagen-targeted MRI was the most sensitive for detection of initial fibrosis (collagen accumulation), while the Gd-Hyd probe was best for detecting and staging fibrinogenesis (active disease activity).

Implications: Targeted molecular MRI may offer noninvasive alternatives to biopsy for the diagnosis and staging of NASH/fibrosis, however the available molecular probes are not yet proven to be safe in humans.

References
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