18F-FDG-PET/CT predicts the distribution of microsatellite lesions in hepatocellular carcinoma.

This study was conducted to investigate whether fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is useful for predicting the distance of intrahepatic metastases and microvascular invasion from the main tumor and the pattern of postoperative recurrence. A total of 89 consecutive patients who underwent 18F-FDG PET/CT prior to liver resection for hepatocellular carcinoma (HCC) between April, 2006 and December, 2011 were enrolled in this study. The distance between the microsatellite lesion and the main nodule (microsatellite distance) was analyzed and measured pathologically. The correlation between maximal standardized uptake values (SUVmax) and microsatellite distance was analyzed and the independent risk factors for microsatellite distance >1 cm were assessed. The postoperative recurrence patterns were divided into no recurrence, intrahepatic recurrence and extrahepatic recurrence. SUVmax and the distribution of microsatellite lesions were compared among these groups. The postoperative recurrence patterns were also analyzed according to the SUVmax and the microsatellite lesion pattern. SUVmax was found to be significantly correlated with the distance from the microsatellite lesion to the main nodule (r=0.57, P<0.0001). On the multivariate analysis of microsatellite distance >1 cm, the only significant factor was SUVmax [P=0.002; hazard ratio=1.60; 95% confidence interval (CI): 1.23-2.26]. The optimal cutoff value of SUVmax for microsatellite distance >1 cm was 8.8. The mean SUVmax and the microsatellite distance were highest in patients with postoperative extrahepatic metastases (8.6 and 9,160 µm, respectively). In conclusion, the SUVmax of 18F-FDG PET/CT reflects microsatellite distance and the patterns of postoperative recurrence in HCC. Therefore, 18F-FDG PET/CT may be a useful imaging modality for determining the resection margin and the treatment protocol for HCC.

Abdominal imaging findings of a patient with hepatocellular carcinoma associated with glycogen storage disease type 1a.

A hepatic tumor was found in a 57-year-old man with glycogen storage disease type 1a (GSD1a) with a mutation in exon 5 of the glucose-6-phosphatase gene (G727T). Partial hepatectomy was performed, and the tumor was histologically diagnosed as moderately differentiated hepatocellular carcinoma (HCC). On contrast-enhanced ultrasonography, the tumor had a late phase defect. Abdominal imaging with other modalities was also performed. More studies are needed to clarify the differences in imaging findings between GSD1a-associated HCC and other tumors such as adenomas.

Evaluation of contrast-enhanced ultrasonography using perfluorobutane (Sonazoid(®)) in patients with small hepatocellular carcinoma: comparison with dynamic computed tomography.

This study aimed to elucidate the efficacy of contrast-enhanced ultrasonography (CEUS) with perfluorobutane (Sonazoid(®)) in the diagnosis of hepatocellular carcinomas (HCCs), particularly small HCCs, by comparing the results with dynamic computed tomography (Dy-CT). Seventy-nine nodules in 69 patients with chronic liver disease, suspected as HCCs were studied. The nodules were selected based on the results of B-mode ultrasonography and/or Dy-CT conducted between January and August 2007. The nodules were divided into two groups: the S-group with tumors ≤2 cm (49 nodules), and the L-group with tumors >2 cm (30 nodules). Typical HCCs were defined, and the nodules were enhanced and shown as defects in the arterial and late phase of Dy-CT, respectively. Target lesions were scanned using CEUS, and the results were compared with those of Dy-CT. The L-group nodules diagnosed as HCCs using Dy-CT were also diagnosed as HCCs using CEUS. In the S-group, the diagnostic sensitivity of CEUS was 94.7% and the specificity was 81.8%. We diagnosed two liver tumors that were detected by CEUS but not by Dy-CT; biopsies revealed one tumor to be a well-differentiated HCC and the other to be an atypical adenomatous hyperplasia. The sensitivity and specificity of CEUS against HCC were high even in the small-size HCCs. Thus, Sonazoid is useful in the screening for small HCCs.