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Background: The sensitivity of 2-[18F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET) for advanced colorectal neoplasms among healthy subjects is not yet fully understood. The present study aimed to clarify the sensitivity by analyzing large-scale data from an asymptomatic screening population.Methods: A total of 7505 asymptomatic screenees who underwent both FDG-PET and colonoscopy at our Cancer Screening Division between February 2004 and March 2013 were analyzed. FDG-PET and colonoscopy were performed on consecutive days, and each examination was interpreted in a blinded fashion. The results of the two examinations were compared for each of the divided six colonic segments, with those from colonoscopy being set as the reference. The relationships between the sensitivity of FDG-PET and clinicopathological features of advanced neoplasms were also evaluated.Results: Two hundred ninety-one advanced neoplasms, including 24 invasive cancers, were detected in 262 individuals. Thirteen advanced neoplasms (advanced adenomas) were excluded from the analysis because of the coexistence of lesions in the same colonic segment. The sensitivity, specificity, and positive and negative predictive values of FDG-PET for advanced neoplasms were 16.9 % [95 % confidence interval (CI) 12.7-21.8 %], 99.3 % (95 % CI 99.2-99.4 %), 13.5 % (95 % CI 10.1-17.6 %), and 99.4 % (95 % CI 99.3-99.5 %), respectively. The sensitivity was lower for lesions with less advanced histological grade, of smaller size, and flat-type morphology, and for those located in the proximal part of the colon.Conclusions: FDG-PET is believed to be difficult to use as a primary screening tool in population-based colorectal cancer screening because of its low sensitivity for advanced neoplasms. Even when it is used in opportunistic cancer screening, the limit of its sensitivity should be considered. [ABSTRACT FROM AUTHOR]

Background: The sensitivity of 2-[F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET) for advanced colorectal neoplasms among healthy subjects is not yet fully understood. The present study aimed to clarify the sensitivity by analyzing large-scale data from an asymptomatic screening population. Methods: A total of 7505 asymptomatic screenees who underwent both FDG-PET and colonoscopy at our Cancer Screening Division between February 2004 and March 2013 were analyzed. FDG-PET and colonoscopy were performed on consecutive days, and each examination was interpreted in a blinded fashion. The results of the two examinations were compared for each of the divided six colonic segments, with those from colonoscopy being set as the reference. The relationships between the sensitivity of FDG-PET and clinicopathological features of advanced neoplasms were also evaluated. Results: Two hundred ninety-one advanced neoplasms, including 24 invasive cancers, were detected in 262 individuals. Thirteen advanced neoplasms (advanced adenomas) were excluded from the analysis because of the coexistence of lesions in the same colonic segment. The sensitivity, specificity, and positive and negative predictive values of FDG-PET for advanced neoplasms were 16.9 % [95 % confidence interval (CI) 12.7-21.8 %], 99.3 % (95 % CI 99.2-99.4 %), 13.5 % (95 % CI 10.1-17.6 %), and 99.4 % (95 % CI 99.3-99.5 %), respectively. The sensitivity was lower for lesions with less advanced histological grade, of smaller size, and flat-type morphology, and for those located in the proximal part of the colon. Conclusions: FDG-PET is believed to be difficult to use as a primary screening tool in population-based colorectal cancer screening because of its low sensitivity for advanced neoplasms. Even when it is used in opportunistic cancer screening, the limit of its sensitivity should be considered. [ABSTRACT FROM AUTHOR]

Purpose: The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods: This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner. Results: The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU]) was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001). The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001) for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures. Conclusion: Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners. [ABSTRACT FROM AUTHOR]

Background: The Liver Cancer Study Group of Japan has designated early hepatocellular carcinoma (HCC) a clinically early-stage HCC corresponding to a high-grade dysplastic nodule as proposed by the International Working Party. Methods: The majority of resected early HCCs were demonstrated as having hypo- or isoattenuation in the arterial and delayed phases of dynamic CT. Results: Only 5% of early HCCs were hyperattenuated on dynamic CT, whereas 94% of advanced small HCC were hyperattenuated. CT arterial portography (CTAP) showed that 66% of early HCCs were hypo- and 34% were isoattenuated. CT hepatic arteriography (CTHA) demonstrated that 55% of them were hypo-, 30% were iso- and the remaining 15% were hyperattenuated. Conclusions: These findings suggest that most early HCCs receive equal or decreased blood supply from both portal and arterial blood flow compared with surrounding hepatic parenchyma. In contrast, 97% of small advanced HCCs were hypoattenuated on CTAP, and 93% were hyperattenuated on CTHA. For nodule-in-nodule type HCC, the central portion of the lesion was hyperattenuating and the peripheral portion was hypoattenuating in the arterial phase of dynamic CT, and both areas became hypoattenuated in the delayed phase. Sixty hypoattenuating nodular lesions in chronic liver disease were followed periodically with helical CT. Thirty-six (60%) of them developed to the hyperattenuating type (attenuation conversion), 21 were unchanged, and 3 disappeared spontaneously. The hyper-in-hypo-attenuating lesions showed rapid progression to entirely enhanced lesions, i.e. overt HCC. Dynamic CT is recommended as one of the low-invasive imaging modalities to follow the hypoattenuating nodules and to determine the optimal treatment with careful attention being given to intratumoral attenuation conversion. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Early hepatocellular carcinoma (HCC) as defined by the Liver Cancer Study Group of Japan would correspond to high-grade dysplastic nodules with small foci of HCC in the majority of cases, using the classification system proposed by the International Working Party. A large number of early HCCs were revealed to be hypo- or isovascular in the arterial phase of dynamic CT. Only 5% of the lesions evaluated were hypervascular, which contrasted with advanced small HCCs, of which 94% were hypervascular. CT arterial portography (CTAP) showed hypoattenuation in 66% of early HCCs and isoattenuation in 34%. CT hepatic arteriography (CTHA) demonstrated hypoattenuation in 55% of early HCC, isoattenuation in 30% and hyperattenuation in 15%. These findings suggest that most early HCCs receive equal or reduced blood supply from both portal and arterial flow compared with surrounding noncancerous parenchyma. In contrast, 97% of small HCCs are hypoattenuated on CTAP, and 93% are hyperattenuated on CTHA. For nodule-in-nodule type HCC (advanced HCC within early HCC), the CT attenuation of the central and peripheral portions revealed areas of isolated advanced HCC and isolated early HCC, respectively. Adenomatous hyperplasia (low-grade dysplastic nodules) was not readily differentiated using the various imaging modalities, mainly due to the smaller size of these lesions compared to early HCC and/or a portal and arterial blood supply very similar to that of the surrounding parenchyma. Hemodynamic changes in cirrhotic liver were similarly evaluated using CTAP and CTHA, and the treatment of early HCC is briefly discussed herein. [ABSTRACT FROM AUTHOR]

During an 11-yr period (1979-1989), we have experienced five patients with idiopathic Budd-Chiari syndrome (BCS), four (80%) of whom had associated hepatocellular carcinoma (HCC). In contrast, the incidence of BCS complicated by HCC was 0.7% of a total of 556 patients who underwent surgery for HCC or were autopsied. Hepatitis B virus-related antigen or antibody was positive in one patient each. Four of our five patients were asymptomatic and were initially diagnosed by ultrasonography (n = 3) or computed tomography (n = 1). The hepatic parenchyma histopathological findings were cirrhosis and fibrosis in one each. Infection of hepatitis B virus rather than BCS was speculated as a causative factor for HCC in two patients. Membranous obstruction with spotty calcification, intrahepatic bizarre communicating vessels, and the dilated anterior longitudinal veins in spinal canal were recognized in three patients. Three patients had two HCCs which were similar in size and arose from the right and left hepatic lobe, separately, suggesting multicentricity of HCC. Both percutaneous transluminal angioplasty with Gruntzig balloon catheters for the obstruction of the inferior vena cava and hepatic arterial embolization for HCC(s) were performed in three patients. These patients survived 29.3 months on average after the diagnosis of BCS complicated by HCC(s). The opened IVC was confirmed to be patent on an average of 26.3 months after the first angioplasty. [ABSTRACT FROM AUTHOR]

Double primary liver cancer, i.e., hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC), was detected by ultrasound (US) during the follow-up of chronic liver disease, and was safely resected in two patients, one synchronously and the other metachronously. On admission, laboratory data were normal except for slightly abnormal liver function tests. One patient (case 1) had a 5.1-cm white firm CCC with several small daughter lesions around it which was enhanced late in computed tomography, and a 2.1-cm well-circumscribed HCC with a pseudocapsule; the two were situated very close to one another in the right posterior segment of the liver. Another patient (case 2) had a small 1.5-cm CCC in the anterior superior area, and 6 yr after the first resection, α-fetoprotein gradually increased and a 4-cm HCC was detected anew and resected; the preoperative diagnosis made by US and ethiadol-computed tomography was correct. The histopathological diagnosis of the noncancerous portion was chronic active hepatitis in both cases. However, it changed to precirrhosis in case 2 during the follow-up. [ABSTRACT FROM AUTHOR]

This report described two patients with hepatocellular carinoma in whom angiographic procedure caused an inadvertent subintimal injury of the hepatic artery, resulting in tumor necrosis. In the first case of a 38-year old male, complete obstruction of the common hepatic artery occurred on the initial angiography. It was followed by marked reduction of the tumor vessels on repeat angiography, and necrosis of about half of the tumor as confirmed by computed tomography. In the other 58-year-old female, severe subintimal injury occurred in the proper hepatic artery followed by obstruction of the feeding arteries. Subsequent computed tomography scan disclosed necrosis of the tumor. Both patients presented the postembolization syndrome that consisted of a transient fever and elevation of blood enzymes. When spontaneous regression or reduction of hepatocellular carcinoma is observed, special attention should he paid regarding whether or not hepatic angiography was performed and clinical symptoms followed it. [ABSTRACT FROM AUTHOR]