Comparison of the diagnostic performance of imaging criteria for HCCs ≤ 3.0 cm on gadoxetate disodium-enhanced MRI

BACKGROUND AND PURPOSE

Imaging-based diagnostic systems play important roles in hepatocellular carcinoma (HCC). We aimed to compare the diagnostic performance of recently updated imaging criteria for HCCs ≤ 3.0 cm on gadoxetate disodium-enhanced magnetic resonance imaging (MRI).

METHODS

493 nodules (399 HCCs, 24 other malignancies, 70 benign) 1.0-3.0 cm from 400 patients, including 322 male (mean age 59.3 ± 9.4 years) and 78 female (mean age 61.2 ± 9.0 years), at risk for HCC who underwent gadoxetate disodium-enhanced MRI between July 2015 and December 2016 were retrospectively evaluated. Final diagnosis was determined histopathologically or clinically. The sensitivity and specificity in diagnosing HCC of the latest versions of four imaging criteria [Liver Imaging Reporting and Data System (LI-RADS), European Association for the Study of the Liver (EASL), Asian Pacific Association for the Study of the Liver (APASL), Korean Liver Cancer Association-National Cancer Center (KLCA-NCC)] were compared using generalized estimating equations.

RESULTS

In 331 only pathologically diagnosed nodules, the sensitivities of both the APASL (86.8%) and KLCA-NCC criteria (85.4%) were significantly higher than the sensitivities of the EASL (71.8%) and LR-5 (71.1%) criteria (p < 0.001 for each pairwise comparison). However, the specificity of LR-5 was significantly higher than that of APASL (92.2% vs. 70.6%, respectively; p = 0.011) but did not differ significantly from the specificities of EASL (84.3%; p = 0.634) and KLCA-NCC (78.4%; p = 0.107).

CONCLUSION

Of the four international imaging criteria, LI-RADS and EASL showed high specificity but suboptimal sensitivity for diagnosing HCCs ≤ 3 cm. However, APASL and KLCA-NCC had a higher sensitivity but a lower specificity than LI-RADS and EASL.

Incorporating the hepatobiliary phase of gadobenate dimeglumine-enhanced MRI in the diagnosis of hepatocellular carcinoma: increasing the sensitivity without compromising specificity

BACKGROUND

Diagnosis of hepatocellular carcinoma (HCC) is centered on wash-in of contrast during the arterial phase followed by washout during the portal or delayed venous phase. Nodules showing hypointensity on the hepatobiliary phase are also likely to represent HCC, however, the role of this phase is not yet established.

PURPOSE

To investigate the role of the hepatobiliary phase on Gadobenate dimeglumine (Gd-BOPTA) magnetic resonance imaging (MRI) in characterizing HCCs lacking the typical arterial enhancement and venous washout.

MATERIAL AND METHODS

Ninety-seven cirrhotic patients (78 men, 19 women; mean age, 58.5 years) who underwent liver transplantation (2004-2012) and Gd-BOPTA enhanced MRI within 3 months of surgery were retrospectively reviewed. A nodule-by-nodule analysis was performed, followed by liver explant correlation. Statistical analysis was then performed by a biostatistician using commercially available software.

RESULTS

A total of 193 HCCs were found in 97 liver explants, of which 24.9% (48/193) were not detectable on imaging. The 145 HCCs seen on imaging showed the typical wash-in/washout pattern (Pattern A) in 46.9% (68/145), arterial enhancement without washout (Pattern B) in 37.9% (55/145), and hypovascularity on arterial and venous sequences (Pattern C) in 15.2% (22/145). Pattern A was exclusive to HCC. Twenty-three of the 55 HCCs showing Pattern B were also hypointense on the hepatobiliary phase (Pattern B1). Combining Pattern B1 with Pattern A raises the sensitivity of HCC characterization from 46.9% to 62.8% (P = 0.007), with no significant compromise on specificity.

CONCLUSION

When coupled with Pattern A, Pattern B1 augments sensitivity of HCC characterization with no significant compromise on the specificity.

Magnetic resonance imaging in cirrhosis: what's new?

Cirrhosis is the main risk factor for the development of hepatocellular carcinoma (HCC). The major causative factors of cirrhosis in the United States and Europe are chronic hepatitis C infection and excessive alcohol consumption with nonalcoholic steatohepatitis emerging as another important risk factor. Magnetic resonance imaging is the most sensitive imaging technique for the diagnosis of HCC, and the sensitivity can be further improved with the use of diffusion-weighted imaging and hepatocyte-specific contrast agents. The combination of arterial phase hyperenhancement, venous or delayed phase hypointensity "washout feature," and capsular enhancement are features highly specific for HCC with reported specificities of 96% and higher. When these features are present in a mass in the cirrhotic liver, confirmatory biopsy to establish the diagnosis of HCC is not necessary. Other tumors, such as cholangiocarcinoma, sometimes occur in the cirrhotic at a much lower rate than HCC and can mimic HCC, as do other benign lesions such as perfusion abnormalities. In this article, we discuss the imaging features of cirrhosis and HCC, the role of magnetic resonance imaging in the diagnosis of HCC and other benign and malignant lesions that occur in the cirrhotic liver, and the issue of nonspecific arterially hyperenhancing nodules often seen in cirrhosis.