Critical analysis of the major and ancillary imaging features of LI-RADS on 127 proven HCCs evaluated with functional and morphological MRI: Lights and shadows

Abstract

PurposeTo report a critical analysis of major and ancillary MR imaging features in assessment of HCC.MethodsRetrospectively we evaluated 70 cirrhotic patients with 173 nodules, which were subjected to MR study at 0 time (MR0), after 3 (MR3) and 6 months (MR6) using two different contrast media. EOB-GD-DTPA was injected at MR0 and MR6, while Gd-BT-DO3A at MR3. Three expert hepatic radiologists reviewed all images, recording, according to LI-RADS, the size, the presence and quality of arterial-phase hyperenhancement, washout and capsule appearance, threshold growth. Additionally, we recorded signal intensity (SI) on T2-W images, on DWI, on apparent diffusion coefficient (ADC) maps and SI on T1-W images of EOB-GD-BPTA hepatospecific phase. Median value of ADC and of Intravoxel incoherent motion related parameters were assessed.Results127 HCCs and 24 dysplastic nodules were assessed. Hypervascular on arterial phase was found in 84 HCCs, washout appearance in 124, capsule appearance in 111, hypointensity on hepatospecific phase in 127, hyperintensity on T2-W sequences and restricted diffusion in 107. Hyper vascular on arterial phase was found in 17 dysplastic nodules, wash-out appearance in 2, hypointensity on hepatospecific phase in 7 while no dysplastic nodules showed capsule appearance, hyperintensity on T2-W and restricted diffusion. Highest accuracy was obtained by washout appearance and hypointense signal on hepatospecific phase (97% and 95%).ConclusionsHypointensity on hepatospecific phase and washout appearance are the most relevant diagnostic sign for differentiating low-risk from high-risk HCC nodules. The capsule appearance, T2-W hyperintensity and restricted diffusion have high positive predictive value.

Prospective Intraindividual Comparison of Magnetic Resonance Imaging With Gadoxetic Acid and Extracellular Contrast for Diagnosis of Hepatocellular Carcinomas Using the Liver Imaging Reporting and Data System

“…The striking difference in LR‐4 categories between the two MRIs was that nine (9.5%) HCCs showed APHE on ECA‐MRI but not on HBA‐MRI, which might be partly responsible for the lower diagnostic performance of HBA‐MRI . This could be explained by the small dosage of HBA‐MRI, which is one‐fourth that of conventional ECA (0.025 versus 0.1 mmol/kg) .…”

LI‐RADS 2017: An update

“…25 Granata et al found that in addition to major imaging features of LI-RADS, hyperintensity on T 2 -weighted images as well as restricted diffusion have a high positive predictive value for HCC. 12 …”

“…Various types of locoregional therapies are available for HCC, such as thermal ablation (eg, radiofrequency ablation, microwave ablation), transcatheter therapies (with or without chemotherapeutic agents), as well as localized radiotherapy. Currently, this algorithm is not designed for systemic therapy or, unless the recurrence is at the surgical margin, in postoperative cases 12 …”

“…APHE is defined by the presence of enhancement that is unequivocally greater than that of the background liver. 12,13 In v2017, the distinction is made between rim and nonrim APHE, depending on whether or not enhancement is primarily confined to the periphery of the observation. 13 For LR-5 categorization, nonrim APHE must be present.…”

“…25 Granata et al found that in addition to major imaging features of LI-RADS, hyperintensity on T 2weighted images as well as restricted diffusion have a high positive predictive value for HCC. 12 In LI-RADS v2017, restricted diffusion (high signal on diffusion-weighted imaging not attributable solely to T 2 shinethrough) is considered an AF of malignancy (although not specific to HCC). Ogihara et al confirmed the utility of diffusion-weighted imaging as an AF for HCC across a number of different vendors and b-values.…”