Material decomposition using iodine quantification on spectral CT for characterising nodules in the cirrhotic liver: a retrospective study

Background There is limited scientific evidence on the potential of spectral computed tomography (SCT) for differentiation of nodules in the cirrhotic liver. We aimed to assess SCT-generated material density (MD) parameters for nodule characterisation in cirrhosis. Methods Dynamic dual-energy SCT scans of cirrhotic patients performed over 3 years were retrospectively reviewed. They were classified as hepatocellular carcinoma (HCC), regenerative or indeterminate, according to the European Association for the Study of the Liver criteria. MD maps were generated to calculate the area under the curve (AUC) and cutoff values to discriminate these nodules in the hepatic arterial phase (HAP) and portal venous phase (PVP). MD maps included iodine concentration density (ICD) of the liver and nodule, lesion-to-normal liver ICD ratio (LNR) and difference in nodule ICD between HAP and PVP. Results Three hundred thirty nodules belonging to 300 patients (age 53.0 ± 12.7 years, mean ± standard deviation) were analysed at SCT (size 2.3 ± 0.8 cm, mean ± SD). One hundred thirty-three (40.3%) nodules were classified as HCC, 147 (44.5%) as regenerative and 50 (15.2%) as indeterminate. On histopathology, 136 (41.2%) nodules were classified as HCC, 183 (55.5%) as regenerative and 11 (3.3%) as dysplastic. All MD parameters on HAP and the nodule difference in ICD could discriminate pathologically proven HCC or potentially malignant nodules from regenerative nodules (p < 0.001). The AUC was 82.4% with a cutoff > 15.5 mg/mL for nodule ICD, 81.3% > 1.8 for LNR-HAP and 81.3% for difference in ICD > 3.5 mg/mL. Conclusion SCT-generated MD parameters are viable diagnostic tools for differentiating malignant or potentially malignant from benign nodules in the cirrhotic liver.

Imaging features of hepatocellular carcinoma with bile duct tumor thrombus：a multicenter study

Background: There are still difficult and challenging problems in diagnosis of hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) before operation. This study aimed to analyze the imaging features of HCC with B1-B3 BDTT. Methods: The clinicopathological data and imaging findings of 30 HCC patients with B1-B3 BDTT from three high-volume institutions were retrospectively reviewed. Eighteen patients underwent computed tomography (CT) scans and twelve patients underwent magnetic resonance imaging (MRI) scans before operation, respectively. The diagnosis of HCC with BDTT was confirmed by postoperative pathologic examination.Results: According to Japanese classification, 5 patients were classified as B1 BDTT, 12 B2, 13 B3, and 82 B4, respectively. The HCC lesions were detected in all patients, and the localized bile duct dilation were detected in 28 (93.3%) patients. The BDTT was observed in all B3 patients and 3 B2 patients, but it was not observed in all B1 patients on CT or MRI. The BDTT showed relatively hypoattenuation on plain CT scans and T1W images, relatively hyperattenuation signals on T2W. The BDTT showed hyperattenuation at hepatic arterial phase with washout at portal venous phase. The localized biliary dilation showed no enhancement at hepatic arterial phase and no progressively delayed enhancement at portal venous phase, but it was more obvious at portal venous phase on CT.Conclusions: The HCC lesions and the localized bile duct dilatation on CT or MRI scans are imaging features of HCC with BDTT, which might facilitate the early diagnosis for B1-B3 BDTT.

Imaging Features of Hepatocellular Carcinoma with Bile Duct Tumor Thrombus: A Multicenter Study

Background: There are still difficult and challenging problems in diagnosis of hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) before operation. This study aimed to analyze the imaging features of HCC with B1-B3 BDTT. Methods: The clinicopathological data and imaging findings of 30 HCC patients with B1-B3 BDTT from three high-volume institutions were retrospectively reviewed. Eighteen patients underwent computed tomography (CT) scans and twelve patients underwent magnetic resonance imaging (MRI) scans before operation, respectively. The diagnosis of HCC with BDTT was confirmed by postoperative pathologic examination.Results: According to Japanese classification, 5 patients were classified as B1 BDTT, 12 B2, 13 B3, and 82 B4, respectively. The HCC lesions were detected in all patients, and the localized bile duct dilation were detected in 28 (93.3%) patients. The BDTT was observed in all B3 patients and 3 B2 patients, but it was not observed in all B1 patients on CT or MRI. The BDTT showed relatively hypoattenuation on plain CT scans and T1W images, relatively hyperattenuation signals on T2W. The BDTT showed hyperattenuation at hepatic arterial phase with washout at portal venous phase. The localized biliary dilation showed no enhancement at hepatic arterial phase and no progressively delayed enhancement at portal venous phase, but it was more obvious at portal venous phase on CT.Conclusions: The HCC lesions and the localized bile duct dilatation on CT or MRI scans are imaging features of HCC with BDTT, which might facilitate the early diagnosis for B1-B3 BDTT.

Role of central hypovascularity in the hepatic arterial phase of dynamic CT on mass-forming intrahepatic cholangiocarcinoma.

205 Background: Intrahepatic cholangiocarcinoma (IHCC) is known as one of most malignant cancers. Recently, the vascularity in the hepatic arterial phase (HAP) of dynamic CT has been reported as a possible prognostic marker in IHCC. The aim of this study is to elucidate the role of central hypovascularity in the HAP on mass-forming IHCC. Methods: Forty patients who underwent initially hepatic resection for mass-forming IHCC were enrolled. The HAP was scanned 40 seconds after the injection of contrast agent. Vascular pattern was classified into three groups; hypervascularity (Hyper) group (n = 8), rim-enhancement (Rim) group (n = 7) and hypovascularity (Hypo) group (n = 25) by a radiologist in reference to Fujita, et al (Eur Radiol 2017). Hypoxia-inducible factor-1 (HIF-1) expression in the surgical specimen was evaluated by immunohistochemistry. The clinicopathological findings were compared among the groups. Results: The advanced stage tended to be more frequent in Hypo group, however, no difference of tumor location (hilar or peripheral) was observed. Overall survival (OS) in Hypo group was worse than that in Hyper group. The OS in Rim+Hypo group, that means central hypovascularity in the tumor, was worse than that in Hyper group. Furthermore, Rim+Hypo group was an independent prognostic factor in OS (HR: 5.44). Regarding the HIF-1 expression, high HIF-1 expression in the central part of the tumor correlated with central hypovascularity in the HAP (25% in Hyper-group and 72% in Rim+Hypo group, respectively). Conclusions: The central hypovascularity (Rim+Hypo group) was an independent prognostic factor, furthermore, high malignant potential of the tumor with central hypovascularity might be related to HIF-1 upregulation.