SUBJECTS AND METHODS. From April 1, 2007, to July 1, 2007, a total of 34 consecutively registered patients (19 men, 15 women; median age, 55 years) with various intraabdominal malignant tumors underwent preoperative CT and composed the study population. All patients underwent superparamagnetic iron oxide–enhanced MRI and portal phase contrast-enhanced 64-MDCT, including CT laparoscopy. CT laparoscopy is a form of volume-rendering 3D imaging of the liver that depicts the liver surface in detail.

RESULTS. Among 23 patients who underwent surgery for management of a primary tumor, four patients had seven superficial metastatic lesions of the liver surface. None of these lesions had been detected with preoperative axial CT or superparamagnetic iron oxide–enhanced MRI. In contrast, CT laparoscopy revealed four of seven lesions in four patients. On a lesion-by-lesion basis, the sensitivity was 57%, the positive predictive value was 100%, and the accuracy was 57%.

CONCLUSION. Our initial experience proves that CT laparoscopy is a promising method for detecting small superficial metastatic lesions of the liver surface. The findings can influence decisions regarding tumor resectability.

MATERIALS AND METHODS. We reviewed T2-weighted fast-recovery fast spin-echo images before and after gadolinium enhancement for 84 patients with 118 focal liver lesions. Solid lesions (22 hepatomas, seven ablated hepatomas, 12 metastatic lesions, six cases of focal nodular hyperplasia, five dysplastic nodules, one adenoma) were proved pathologically or with multiple follow-up studies. Nonsolid lesions were diagnosed as hemangiomas (n = 33) or cysts (n = 32) on the basis of imaging features. Two blinded radiologists interpreted the images independently, reading unenhanced images first and gadolinium-enhanced images at least 2 weeks later. Lesion conspicuity was ranked as follows: 1, poor; 2, moderate; 3, good; 4, excellent. The sign test was used for qualitative scoring of imaging pairs (unenhanced and gadolinium enhanced). The Fisher's exact test was used for subgroup analysis of solid and nonsolid lesions.

RESULTS. On gadolinium-enhanced T2-weighted images, 21 (17.8%) of 118 of the lesions had improved conspicuity, 86 (72.9%) had no difference in conspicuity, and 11 (9.3%) appeared worse. No statistically significant difference was found between unenhanced and enhanced images (p = 0.11), but a trend toward improved conspicuity with gadolinium enhancement was observed. Subgroup analysis showed that on gadolinium-enhanced T2weighted images, visualization of solid hepatic lesions (28.3%) was significantly better than that of nonsolid lesions (9.2%) (p = 0.01).

CONCLUSION. Compared with unenhanced T2-weighted images, gadolinium-enhanced T2-weighted images had a trend toward improved conspicuity of focal liver lesions. Subgroup analysis showed that visualization of solid lesions benefited significantly more from use of gadolinium-enhanced T2-weighted sequences than did visualization of nonsolid lesions.

MATERIALS AND METHODS. We retrospectively evaluated 248 patients who had been referred for planning sonography at our department between October 2005 and February 2006. We reviewed the radiologic reports of 256 planning sonography examinations in terms of the rate of feasible cases and the reasons for infeasibility. The reasons for infeasibility were classified in six categories: an inconspicuous tumor, an inadequate electrode path, an organ vulnerable to collateral thermal damage, a tumor that was too large or too many tumors, and a high risk of the heat sink effect. In addition, we assessed the treatment modality for the patients who were determined to have HCCs for which percutaneous radiofrequency ablation was not feasible.

RESULTS. In 141 (55%) of the 256 planning sonography examinations, percutaneous radiofrequency ablation was feasible. The remaining 115 (45%) planning sonography examinations revealed that radiofrequency ablation was not a feasible procedure. The reasons for infeasibility included an inconspicuous tumor in 77 patients (55.8%), an inadequate electrode path in 33 patients (23.9%), an organ vulnerable to collateral thermal damage in 14 patients (10.1%), a tumor that was too large or too many tumors in eight patients (5.8%), a high risk of the heat sink effect in five patients (3.6%), and a portal vein thrombosis in one patient (0.7%). One reason for infeasibility was found in 96 patients, two reasons in 19 patients, and four reasons in one patient. Seventy (61.9%) of 113 patients for whom radiofrequency ablation was not feasible underwent transcatheter arterial chemoembolization as an alternative treatment.

CONCLUSION. In approximately half of the patients for whom percutaneous radiofrequency ablation of HCC is requested, the procedure is not feasible, mainly due to inconspicuous tumors, at planning sonography. Additional objective criteria for assessing the feasibility of radiofrequency ablation and therapeutic strategies according to the reasons for infeasibility should be investigated further.

SUBJECTS AND METHODS. Nine healthy controls and 30 patients with biopsy-proven hepatitis C virus–related liver disease participated in this prospective study. Degree of fibrosis and histologic activity were scored according to the METAVIR classification. The percentage of involved hepatocytes was used to grade steatosis. Hepatic spectra were obtained with a 3-T spectroscopic system. Tenfold cross-validated stepwise discriminant analysis was performed to classify disease severity on the basis of the spectroscopic findings.

RESULTS. There was a strong correlation between ¹H-MR spectroscopically measured lipid concentration and the degree of steatosis at histologic examination (r = 0.9236, p < 0.0001). This finding enabled clear separation of groups according to degree of histologically determined steatosis. Variation in lipid concentration was consistent with the degree of steatosis (r = 0.7265, p < 0.0001) and stage of fibrosis (r = 0.8156, p < 0.0001). In univariate analysis, concentrations of both choline-containing compounds and glutamine–glutamate complex had a direct correlation with histologic grade (p < 0.0001) and degree of steatosis (p < 0.0001) but not with stage of fibrosis (p > 0.05). In multivariate analysis, the only factor independently associated with concentrations of choline-containing compounds and glutamine–glutamate complex was histologic grade. In cross-validated discriminant analysis based on choline-containing compound, glutamine–glutamate complex, and lipid resonance, 70% (21 of 30) of the histologic grade groups and 73% (22 of 30) of the steatosis groups were correctly classified.

CONCLUSION. Hydrogen-1 MR spectroscopy can be an alternative to liver biopsy in the evaluation of steatosis and necroinflammatory activity in liver disease but is not useful for complete evaluation of hepatic fibrosis.

CONCLUSION. In all three patients, more than 100 liver adenomas revealed no metabolism of the new liver-specific contrast agent in the delayed phase. Because of absent or strongly reduced intracellular uptake of gadoxetic acid in all adenomas during delayed contrast-enhanced series, differentiation of adenomas from dysplastic or malignant lesions was not possible.

CONCLUSION. Radiologists should be aware of the etiologic factors of biliary tract inflammation being proposed. They should also understand new approaches to imaging of the biliary tract.

CONCLUSION. We discuss the current and evolving imaging tests in the evaluation of hepatic fatty content, inflammation, and fibrosis.

SUBJECTS AND METHODS. The study included 135 patients with known or suspected HCC who underwent dynamic CT on a 64-detector scanner and 47 were found to have 71 hypervascular HCCs. The patients were randomly assigned to one of three protocols: A contrast dose of 450, 525, or 600 mg I/kg of body weight was delivered over 30 seconds in protocols A, B, and C, respectively. We measured the tumor–liver contrast (TLC) during HAP in the three groups and compared the results. Two radiologists qualitatively evaluated tumor conspicuity during HAP using a 3-point scale; their results were compared.

RESULTS. The TLC in protocols A, B, and C was 26.5, 38.4, and 52.3 H, respectively; the difference was significant between protocols A and B (p = 0.05), A and C (p < 0.01), and B and C (p = 0.02). In our qualitative analysis of tumor conspicuity, the mean score for protocols A, B, and C was 1.6, 2.3, and 2.7, respectively; there was a significant difference between protocols A and B and A and C, but not between protocols B and C.

CONCLUSION. The administration of a total iodine dose of 525 mg or more per kilogram of body weight is desirable for the good or excellent depiction of hypervascular HCC, although the administration of 450 mg I/kg of body weight can depict hypervascular HCC.

SUBJECTS AND METHODS. Doppler sonography examinations were prospectively performed in 54 patients within 24 hours after living donor liver transplantation with a modified right lobe graft in which large (> 5 mm) middle hepatic vein (MHV) tributaries were reconstructed. The number, flow direction, and waveform of the MHV tributaries; the echogenicity of the surrounding parenchyma; and the flow direction of the corresponding portal branch were evaluated. Hepatic venous congestion was diagnosed when there was no color flow or a monophasic waveform of an MHV tributary. The sensitivity of Doppler sonography for the detection of MHV tributaries was assessed using donors' preoperative CT scans and surgical records as references. The diagnostic values of Doppler sonography for hepatic venous congestion were assessed using recipients' postoperative CT scans as references. Differences in prevalence of Doppler sonography findings between the group with hepatic venous congestion and the non–hepatic venous congestion group were assessed.

RESULTS. Doppler sonography enabled us to identify 90% (155/173) of all and 98% (129/131) of the large MHV tributaries. The sensitivity and specificity of Doppler sonography for hepatic venous congestion were 90% (28/31) and 77% (96/124), respectively, for all and 88% (15/17) and 85% (95/112), respectively, for large MHV tributaries. Parenchymal hyperechogenicity was more commonly seen in the hepatic venous congestion group (65%, 20/31) than in non–hepatic venous congestion group (6%, 7/124) (p < 0.01). All five MHV tributaries with reversed flow were seen in the non–hepatic venous congestion group. All five portal branches with hepatofugal flow were seen in the hepatic venous congestion group.

CONCLUSION. Doppler sonography provides a reliable noninvasive surveillance tool for hepatic venous congestion in a modified right lobe graft during the early postoperative period after living donor liver transplantation.

CONCLUSION. Various focal hepatic lesions can accompany peritumoral sparing of fatty infiltration in patients with hepatic steatosis, and they can manifest with an atypical sonographic appearance.