Search

BACKGROUND: This was an observational study of Japanese participants who underwent low-dose computed tomographic (LDCT) lung cancer screening between February 2004 and March 2012, to evaluate the lung cancers in never-smokers and smokers. METHODS: The study population consisted of a total of 12,114 subjects [never-smokers, 6,021 (49.70%); smokers with

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. 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. 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. 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.

Purpose To evaluate interobserver agreement in regard to measurements of focal ground-glass opacities (GGO) diameters on computed tomography (CT) images to identify increases in the size of GGOs. Materials and Methods Approval by the institutional review board and informed consent by the patients were obtained. Ten GGOs (mean size, 10.4 mm; range, 6.5–15 mm), one each in 10 patients (mean age, 65.9 years; range, 58–78 years), were used to make the diameter measurements. Eleven radiologists independently measured the diameters of the GGOs on a total of 40 thin-section CT images (the first [n = 10], the second [n = 10], and the third [n = 10] follow-up CT examinations and remeasurement of the first [n = 10] follow-up CT examinations) without comparing time-lapse CT images. Interobserver agreement was assessed by means of Bland-Altman plots. Results The smallest range of the 95% limits of interobserver agreement between the members of the 55 pairs of the 11 radiologists in regard to maximal diameter was −1.14 to 1.72 mm, and the largest range was −7.7 to 1.7 mm. The mean value of the lower limit of the 95% limits of agreement was −3.1 ± 1.4 mm, and the mean value of their upper limit was 2.5 ± 1.1 mm. Conclusion When measurements are made by any two radiologists, an increase in the length of the maximal diameter of more than 1.72 mm would be necessary in order to be able to state that the maximal diameter of a particular GGO had actually increased.

We have conducted an initial evaluation on the potential of combining noncontrast magnetic resonance imaging (MRI) and ultrasonography (US) to screen for pancreatic cancer. An independent ethics committee approved this study. A total of 2511 patients who underwent US were enrolled. Among them, noncontrast MRI was performed in patients in whom the entire pancreas was difficult to depict or in those with USsuspected pancreatic lesions. In total, using 1.5-T MRI, T1- and T2-weighted imaging, magnetic resonance cholangiopancreatography, and diffusion-weighted imaging, we acquired a variety of images. The efficacy of US and MRI in screening for pancreatic lesions, including pancreatic cancer, was evaluated. Of 2511 patients, 184 underwent MRI, and the pancreas was demonstrated in all of them. Among the 2511, five pancreatic cancers were detected by MRI combined with US (detection rate 0.20%). Of the five pancreatic cancers, three were detected by US (detection rate 0.12%) and two by MRI. Four of the five pancreatic cancers were resectable. By combining noncontrast MRI with US, pancreatic cancer can be detected with high accuracy. Other pancreatic lesions that require follow-up, including intraductal papillary mucinous neoplasms, can also be detected. Thus, pancreatic cancer screening with a combination of US and MRI is suggested.

To achieve better prognosis and quality of life for patients with rectal cancer, extent of surgery and neoadjuvant chemoradiotherapy should accurately reflect disease extent. The aim of this study was to evaluate accuracy of high-resolution magnetic resonance imaging (HRMRI) for preoperative staging of rectal cancer.Between 2001 and 2003, 104 patients with primary rectal cancer were examined with HRMRI and underwent radical surgery. Transmural invasion depth and lymph node metastasis were assessed prospectively and classified according to the American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) system by both HRMRI and histopathology, and results were compared. Criteria for mesorectal and lateral pelvic lymph node involvement were short-axis diameters ofor =5 mm andor =4 mm, respectively.There were 15 pT1, 25 pT2, 50 pT3, and 14 pT4 tumors. Overall accuracy rate for transmural invasion depth was 84%. The mesorectal fascia could be visualized in 98% of patients. Twenty-three patients had mesorectal fascia involvement and the overall accuracy rate was 96% (sensitivity, 96%; specificity, 96%). Fifty-three patients had mesorectal lymph node metastasis and the overall accuracy rate was 74% (sensitivity, 83%; specificity, 64%). Lateral pelvic lymph node metastasis was observed in 15 patients and the overall accuracy rate was 87% (sensitivity, 87%; specificity, 87%).HRMRI was moderately accurate for prediction of mesorectal lymph node metastasis and highly accurate regarding transmural invasion depth, and mesorectal fascia and lateral pelvic node involvement. Therefore, HRMRI appears useful for preoperative decision-making in rectal cancer treatment.

The sensitivity of 2-[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.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.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.

The purpose of this study was to clarify the natural outcomes of hypoattenuating nodular lesions in patients with virus-related chronic liver disease depicted on dynamic CT.Sixty lesions (mean size, 1.3 cm) exhibiting hypoattenuation or isoattenuation in the arterial and delayed phases of dynamic CT were retrospectively evaluated with additional CT (mean, six examinations) for a mean period of 838 days. The primary end point was emergence of hyperattenuating areas within hypoattenuating lesions, a phenomenon called attenuation conversion. Cumulative attenuation conversion rates suggesting rates of malignant transformation were calculated with the Kaplan-Meier method, and factors affecting attenuation conversion rate were analyzed with the Cox proportional hazard model.Thirty-six (60%) of 60 hypoattenuating lesions developed to hyperattenuating lesions, 21 were unchanged, and three disappeared spontaneously. The 36 lesions that became hyperattenuating were divided into two subgroups according to lesion enhancement pattern: hyper-in-hypoattenuating (n = 25) and entirely hyperattenuating (n = 11). The cumulative attenuation conversion rates for the 60 hypoattenuating lesions were 15.8%, 44.3%, and 58.7% at 1, 2, and 3 years. The hyper-in-hypoattenuating lesions showed more rapid progression to entirely enhanced lesions. Positive results for hepatitis C viral antibody (p = 0.028) and initial lesion size (p = 0.007) showed a positive correlation with attenuation conversion rate.Hypoattenuating hepatic nodular lesions in chronic liver disease depicted on dynamic CT have high malignant potential and should be followed with special attention to conversion from hypoattenuation to hyperattenuation to determine the optimal timing of treatment.

Aim: To study the clinicopathologic characteristics of hepatic nodular lesions with high attenuation (increased portal blood flow) compared with surrounding hepatic parenchyma on computed tomography (CT) during arterial portography (CTAP). Methods : For six lesions found in six patients demonstrated as a high-attenuated mass by CTAP, CT during hepatic arteriography (CTHA; n = 3 patients), digital subtraction hepatic arteriography (n = 6) and conventional helical CT (n = 6) were evaluated retrospectively and compared with histopathologic findings (n = 4). Pathologic diagnosis was atypical adenomatous hyperplasia, nodule-in-nodule hepatocellular carcinoma (HCC) in one resected lesion each and overt HCC in two biopsied lesions. Two patients did not undergo any therapy and were followed up. Results : The average size of lesions was 2.2 cm (range 1.2–3.5 cm). The CTAP revealed high attenuation in all six lesions; entirely within the lesion (n = 4 lesions) or peripherally with a central low attenuation (n = 2). In contrast, CTHA showed low attenuated lesions; entirely within the mass (n = 2) or peripherally with a central high-attenuated spot (n = 1). Hepatic arteriogram revealed only two hypervascular lesions; entirely and partially in one each. In the arterial phase of helical CT, all but one lesion were iso- or hypo-attenuated. In two patients who were followed up to 39 and 55 months without therapy, neither tumor growth nor hemodynamic change of the lesion was recognized on CT. Conclusions: Even though the incidence of hepatic nodular lesions demonstrated as high attenuating on CTAP is low, all but one lesion in the current series showed iso- or hypo-attenuation on CTHA and/or helical CT, suggesting the hemodynamics are reciprocal between CTAP and CTHA. One exceptional lesion that showed high attenuation on both CTAP and conventional CT was pathologically advanced HCC. Based on the follow-up study of two untreated patients, this kind of lesion with high attenuation on CTAP seems to grow slowly. © 2002 Blackwell Publishing Asia Pty Ltd

Aims: To evaluate haemodynamic and vascular changes in non-alcoholic (viral) cirrhosis on conventional computed tomography (CT), CT arteriography (CTA) and CT arterial portography (CTAP), and to determine the cause of the observed reticular stain on angiography. Methods: Using surgically resected liver specimens from 31 patients with viral hepatitis associated hepatocellular carcinoma, images of conventional CT, CTA, CTAP and the sinusoidal phase of hepatic arteriography were retrospectively analysed and compared with pathology of the non-cancerous portion of the liver. Results: Computed tomography arteriography showed inhomogeneous enhancement (diffuse, low-density nodules) in a total of 16 samples (52%); in eight of 10 (80%) cirrhotic livers, three of six (50%) precirrhotic livers, five of 12 (42%) livers with chronic active hepatitis and none of three with no active liver disease. The frequency of inhomogeneous enhancement became significantly higher with increasing severity of parenchymal damage (P < 0.05). In contrast, conventional CT and CTAP showed homogeneous enhancement in all 31 (100%) patients. There was no correlation between inhomogeneous enhancement on CTA and reticular staining on sinusoidal-phase hepatic angiograms. Inhomogeneous enhancement was frequently seen in patients with hepatitis B surface antigen and/or anti-hepatitis C virus antibody compared with those without them (P < 0.05). Conclusion: The CTA was much more sensitive in detecting haemodynamic changes in the cirrhotic liver than CTAP, conventional CT and sinusoidal-phased hepatic angiography. Further study is required to clarify the mechanism of inhomogeneous enhancement on CTA and homogeneous enhancement on CTAP seen in cirrhosis.

A 5-cm pheochromocytoma located in segment 7 of the liver was found incidentally in a 45-year-old man with mild diabetes mellitus and hypertension, and resected. The tumor was demonstrated by computed tomography and magnetic resonance imaging to have completely invaginated itself into the liver and to be receiving blood from a dilated right hepatic artery alone. Surgery revealed the hepatic mass to be tightly adherent to the right adrenal gland. The histopathologic diagnosis was pheochromocytoma growing exophytically from the right adrenal gland. There was no association with multiple endocrine neoplasia type 1 and type 2. A postoperative 131I metaiodobenzylguanidine scan revealed no accumulation, and the patient is currently doing well without recurrence or hypertension one year after the operation. A pheochromocytoma deeply invaginating into the liver should be considered in the differential diagnosis of primary hypervascular hepatic tumors.

PURPOSE: To clarify the diagnostic importance of wedge-shaped areas of increased signal intensity that surround liver tumors on T1-weighted magnetic resonance (MR) images. MATERIALS AND METHODS: In five patients with hepatic tumors, T1-weighted MR images that demonstrated wedge-shaped areas of increased signal intensity in the liver were reviewed; findings were compared with those at surgical and histologic examinations. RESULTS: MR images showed localized intrahepatic bile duct dilatation lateral (three patients) and medial (two patients) to liver tumors within the wedge-shaped areas. At histopathologic examination, intraductal tumor growth was seen in local bile ducts in the same areas in five patients, and lipofuscin deposits were seen in the cytoplasm of atrophic hepatocytes in three patients. CONCLUSION: On T1-weighted images, wedge-shaped areas of increased signal intensity associated with liver tumors indicate intraductal tumor extension in intrahepatic bile ducts. T1 shortening is possibly caused by lipofuscin deposits in atrophic hepatocytes.

For two patients with partial Budd‐Chiari syndrome secondary to hepatocellular carcinoma, dynamic CT was evaluated. The obstructed hepatic veins were both the middle and left hepatic veins in Case 1 and the right hepatic vein in Case 2. The area affected by obstructed hepatic vein(s) was seen as low density on both unenhanced and contrast enhanced CT in Case 1 and as high density on enhanced CT in Case 2. The border of attenuation differences caused by the obstruction of the middle (Case 1) or right (Case 2) hepatic vein was intersegmental planes of the anterior segment of the right lobe, and that caused by the obstruction of the left hepatic vein was the intersegmental plane of the medial third of the left lateral segment. Once intersegmental attenuation difference is recognized on CT, partial Budd‐Chiari syndrome should be considered.

Tc-99m pertechnetate scintigraphy was compared with Tl-201 chloride and Ga-67 citrate to evaluate the avidity of Tc-99m pertechtate for malignant soft-tissue tumors. Twenty-three patients with malignant soft-tissue tumors underwent scintigraphic studies. All 23 received Tc-99m and Tl-201, whereas 14 also were injected with Ga-67. In 21 (91%) of the 23 patients, Tc-99m accumulated extensively in the tumors. Tl-201 accumulated in 12 (52%) of the 23 tumors. Ga-67 accumulated in only 5 (36%) of the 14 tumors. The avidity of Tc-99m for myxoid tumors was markedly different from the other two agents. Tc-99m accumulated in all eight myxoid tumors, while neither Tl-201 or Ga-67 showed marked accumulation except for one patient with increased accumulation of Tl-201. This study shows that Tc-99m pertechnetate has the potential to localize malignant soft-tissue tumors and may be useful in the evaluation of these tumors.

Objective: To clarfy imaging and clinicopathologic features of lymphoepithelial cysts (LEC), a benign lesion of the pancreas. Materials and Methods: Two male patients with LECs that were found incidentally and proven surgically were reviewed. Results: Sonography revealed a hypoechoic mass in both cases, one of which had septation and an intracystic isoechoic component within it. The mass was shown as low attenuation on unenhanced CT, and the intracystic solid component was not enhanced by dynamic CT or computed tomographic arteriography. One lesion had calcifications around the mass. Magnetic resonance imaging showed hyper- in hypointensity on T1-weighted imaging and hypo- in hyper- on T2-weighted imaging in one case. Both lesions were located on the surface of the head of the pancreas, and the main pancreatic ducts appeared normal on endoscopic retrograde pancreatography. Both patients were asymptomatic. Conclusion: These imaging and clinical findings suggest LEC, which should be considered when one encounters cystic lesions of the pancreas

A 64-year-old man who underwent hepatectomy for hepatocellular carcinoma (HCC) 4 years ago followed by transarterial chemoembolization for recurrent foci 1 year later had a thrombus in the inferior vena cava (IVC). Tumor thrombus derived from HCC was suspected owing to the increase in size and hepatic arteriography was performed. Common hepatic arteriography demonstrated a small stain suggesting a recurrent HCC in the remnant liver. However, CT during hepatic arteriography revealed that the stain localized not in the liver but within the thrombus in the IVC; there was no recurrent HCC in the liver. The dense stain associated with thin neovasculature developed through the thrombus was recognized. The thrombus spontaneously regressed 8 months later. It was speculated that the neovasculature played an important role in a process of absorption of the thrombus. One should note that the stain shown on angiography does not always suggest that the lesion is localized in the liver and is malignant.

To evaluate interobserver agreement in regard to measurements of focal ground-glass opacities (GGO) diameters on computed tomography (CT) images to identify increases in the size of GGOs.Approval by the institutional review board and informed consent by the patients were obtained. Ten GGOs (mean size, 10.4 mm; range, 6.5-15 mm), one each in 10 patients (mean age, 65.9 years; range, 58-78 years), were used to make the diameter measurements. Eleven radiologists independently measured the diameters of the GGOs on a total of 40 thin-section CT images (the first [n = 10], the second [n = 10], and the third [n = 10] follow-up CT examinations and remeasurement of the first [n = 10] follow-up CT examinations) without comparing time-lapse CT images. Interobserver agreement was assessed by means of Bland-Altman plots.The smallest range of the 95% limits of interobserver agreement between the members of the 55 pairs of the 11 radiologists in regard to maximal diameter was -1.14 to 1.72 mm, and the largest range was -7.7 to 1.7 mm. The mean value of the lower limit of the 95% limits of agreement was -3.1 ± 1.4 mm, and the mean value of their upper limit was 2.5 ± 1.1 mm.When measurements are made by any two radiologists, an increase in the length of the maximal diameter of more than 1.72 mm would be necessary in order to be able to state that the maximal diameter of a particular GGO had actually increased.

Clinicoradiological features were studied in 20 patients with 22 mass lesions of combined hepatocellular carcinoma and cholangiocarcinomas and findings of computed tomography in 12 of these patients with 14 hepatocellular carcinoma-cholangiocarcinomas. Five of these patients also had single overt hepatocellular carcinomas. The incidence of hepatocellular carcinoma-cholangiocarcinoma was 3.3% among the patients with primary liver cancer treated in our hospital. HBsAg was present in 25%, and increased levels of serum alpha-fetoprotein (> 200 ng/ml) and carcinoembryonic antigen (> 5 ng/ml) were found in 25% and in 47%, respectively. Associated cirrhosis was present in 60%. Analysis of 14 hepatocellular carcinoma-cholangiocarcinomas in 12 patients in whom the enhancement pattern on dynamic computed tomography and pathological findings could be studied and compared suggested three tumor types. Nine lesions (type A) were demonstrated only as areas with high-density peripheries in the early phase of enhancement that evolved into a pattern of peripheral low density and central high density in the late phase. Four masses (type B) were shown as hyperdense tumors (early phase) that changed to low density in the late phase. One mass (type C) was seen as a low-density lesion that did not change. Histopathologically, type A comprised hepatocellular carcinoma-predominant components in the peripheral area, cholangiocarcinoma-predominant components with abundant fibrous stroma in the central area and a tissue transitional between the two in the midzone. By contrast, two of four type B masses comprised hepatocellular carcinoma with scattered cholangiocarcinoma components throughout the tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

This study was conducted to retrospectively evaluate the variation of CAD performance utilizing two different FFDM systems in normal clinical cases.

To differentiate focal nodular hyperplasia (FNH) from other hepatic tumors, especially hepatocellular carcinoma, we evaluated the hemodynamics of histologically proved FNH in three patients, two by arterial angio-CT and one by microangiography of the resected specimen. These studies demonstrated the centrifugal blood supply of FNH (early filling of central tumor vessels radiating to periphery, and lobulated tumor stains with central low density area in the late phase), which could not be demonstrated by dynamic CT or hepatic angiography. Arterial angio-CT is useful as a further study, when differential diagnosis of FNH is uncertain by other imaging techniques.

The prevalence of colon cancer has seen strong demand in screening for colorectal neoplasia, and this has drawn considerable attention to the technological advances in Computed Tomographic Colonography (CTC). With the assistance of an oral contrast agent, an imaging technique known as Electronic Cleansing (EC), can affect virtual cleaning of the computed tomography (CT) images, to remove fecal material that is tagged by the agent. Technical problems can arise with electronic cleansing however, when the air lumen causes distortions to the tagged regions which result in partial volume effects. Combining the simple image arithmetic of an electronic cleansing algorithm, with a vertical motion filter at the fluid level of the bowel, artifacts such as those caused by an air lumen are eliminated. Essentially, the filter becomes a vector for that carries the measurement of vertical motion to neutralise the artifact that is causing partial volume effects. Results demonstrate that despite its simplicity, this technique offers accuracy and is able to successfully maintain the normal intra-colonic structure, while supporting digital leaning of tagged residual material appearing on the colon wall.

Three-dimensional (3D) imaging of the large intestine is globally called computed tomography colonography (CTC). CTC has been intensively investigated for application in colorectal cancer screening in Western countries and with the advent of multi-slice CT (MSCT), which provides effective high resolution in 3D CT images, the diagnostic use of CT for colorectal lesions has become a concept widely accepted throughout the world. Computer-aided detection (CAD) for colorectal polyps using digital CT image data and digital pre-processing are also advancing in the West. Compared with colonoscopy, which depends largely on the skill of the performer, CTC produces objective and reproducible diagnostic images and presents a high probability of standardizing examination protocols. Development of effective systems for screening colorectal lesions is expected, leveraging the excellent processing capability of MSCT to enhance 3D visualization and allow efficient detection.

The objective of this study was to develop a computing tool for full-automatic segmentation of body fat distributions on volumetric CT images. We developed an algorithm to automatically identify the body perimeter and the inner contour that separates visceral fat from subcutaneous fat. Diaphragmatic surfaces can be extracted by model-based segmentation to match the bottom surface of the lung in CT images for determination of the upper limitation of the abdomen. The functions for quantitative evaluation of abdominal obesity or obesity-related metabolic syndrome were implemented with a prototype three-dimensional (3D) image processing workstation. The volumetric ratios of visceral fat to total fat and visceral fat to subcutaneous fat for each subject can be calculated. Additionally, color intensity mapping of subcutaneous areas and the visceral fat layer is quite obvious in understanding the risk of abdominal obesity with the 3D surface display. Preliminary results obtained have been useful in medical checkups and have contributed to improved efficiency in checking obesity throughout the whole range of the abdomen with 3D visualization and analysis.

Gastric endoscopy has not yet been recommended for organized or population-based cancer screening because at the moment, the sole criterion for evaluating the effectiveness of cancer screening is the reduction in the death rate, and not the mere detection of cancer. Nevertheless, compared with X-ray screening, which has normally been recommended, endoscopic screening is better at finding small lesions, at finding cancer at its earlier stages, making it more easily and economically treatable, and allows on-the-spot biopsies. Opportunistic, individually initiated screening by endoscopy is more and more in demand. Therefore, its excellent efficacy needs to be matched by improved toleration, improved safety, and improved manpower efficiency so that it can be standardized and utilized to its full diagnostic, therapeutic, and quality-of-life potential.

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.

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 × 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm × 16 or 0.5 mm × 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, PLOS ONE, 10(9), e0137165; 2015

Background: The Research Center for Cancer Prevention and Screening program is a one-arm prospective study designed to evaluate the effect of multiple modalities for cancer screening. Basic programs consist of screening tests for cancer of the lung, esophagus, stomach, colon, rectum, liver, gall bladder, pancreas and kidneys, in addition to prostate cancer screening for males and breast, cervical, endometrial and ovarian cancer screenings for females. Objective: To investigate the possibility of overdiagnosis, we compared the observed numbers with expected numbers based on the model. Methods: We calculated the expected number of cancers on the basis of negative or positive historyofscreeningtestswithinthepreviousyear,basedonassumedsensitivityandsojourntime. Observed numbers of screen-detected cases for stomach, colorectal, lung, prostate and breast cancer were compared with expected numbers. Results:From February 2004 to January 2005, 3786 participants wereenrolled in our study. The overall cancer detection rate was 5.8% (119/2061) for males and 4.1% (71/1725) for females. No statistically significant difference was found between observed and expected cases for colorectal cancer screening, gastric cancer screening for females and lung cancer screening for males. Observed numbers of breast, prostate and lung cancer for females exceeded those expected (P < 0.05). Conclusions:Although cancer screening programs in the present study increased the detection of potentially curable cancers, these modalities, particularly lung, breast and prostate screening, might detect cancers which would not necessarily be clinically significant. We should therefore weigh up benefit and harm for such cancer screening programs.

As a result of future advancements in image engineering and computer technology, digital radiographic systems and MDCT systems will continue to evolve, and it can be predicted that new diagnostic methods that utilize the advantages of digitalization in the radiological diagnosis of gastric carcinoma will also be developed. MDCT gastrography has little potential at present as a diagnostic method for the primary lesions of gastric carcinoma. However, with further advances in MDCT, higher-speed examinations, improved image quality, and optimization of exposure dose, it appears certain that MDCT gastrography will gradually replace radiography, endoscopy, and ultrasound endoscopy.

Purpose: To elucidate the morphologic appearance of small non-tumorous arterioportal (AP) shunts mimicking hepatocellular carcinoma on helical computed tomography (CT), their associated outcomes, and their relationship with alpha-fetoprotein levels in patients with chronic liver disease. Materials and Methods: Ten patients with multiple AP shunts on dynamic helical CT were evaluated. A non-tumorous AP shunt was defined as no increase or spontaneous regression in size on follow-up CT scans. The number and shape of shunts more than 5 mm in diameter were studied on a segment-by-segment basis on the initial CT scan, and compared with those on follow-up CT scans. Alpha-fetoprotein levels were measured at the same time as CT scanning was performed. Results: Ten patients with 86 AP shunts (range 0.5–3.8 cm; mean 1.2 cm) underwent arterial, portal and delayed phase imaging of the entire liver. The AP shunts were geographic (44%), round (33%) or wedge-like (23%) in shape. All shunts changed from high- to iso-attenuation on the delayed phase CT. A follow-up CT (mean 73 days) revealed spontaneous disappearance in all but three (97%) of the 86 AP shunts. Furthermore, 16 new shunts appeared in different segments from the primary ones in four patients. The rapid elevation of alpha-fetoprotein levels to 5–10-fold higher than the baseline level was recognized at the same time as the initial appearance of AP shunts in three patients (30%). Further follow-up CT scans detected solitary hepatocellular carcinomas in four patients at a mean 1283 days after the initial CT. The location of the hepatocellular carcinomas was quite different from those of the initially recognized AP shunts. Conclusions: Non-tumorous AP shunts varied in CT appearance and demonstrated iso-attenuation in the delayed phase, most of which disappeared within 4 months. For these multiple small stains in chronic liver disease, periodic follow-up CT is recommended rather than alternative invasive interventions, even though there was an association with rapid elevation of alpha-fetoprotein levels.

OBJECTIVE. The aim of our study was to assess the accuracy of thin-section MRI performed with a phased-array coil as a technique for the preoperative evaluation of pelvic anatomy and tumor extent in patients with rectal cancer.CONCLUSION. Thin-section MRI with a phased-array coil is accurate and reliable for preoperative evaluation of pelvic anatomy and depth of transmural tumor invasion. Thus, it may be helpful in the selection of the appropriate treatment for patients with rectal cancer.

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.

Background: We describe the computed tomographic (CT) and magnetic resonance imaging (MRI) findings of hepatic metastases caused by soft tissue angiosarcomas to clarify the relation between radiologic appearances and clinicopathologic features. Methods: CT and MR examinations of 13 patients with hepatic metastases of soft tissue angiosarcoma were retrospectively analyzed. Results: Contrast-enhanced CT images showed multiple hypoattenuating lesions relative to the adjacent liver parenchyma. Lesions contained peripheral areas of enhancement in eight patients (62%). Tumors showed cystic attenuation with fluid–fluid levels, which were suggestive of hemorrhage in five patients (38%). In one patient (8%) with cystic attenuation and fluid–fluid levels, lesions also contained marked enhanced nodular portions located centrally or peripherally. On T1-weighted MR images, all four liver tumors appeared heterogeneous and hypointense relative to adjacent liver parenchyma. Fluid–fluid levels were identified on T2-weighted MR images in five patients (38%). After an intravenous bolus of gadolinium-based contrast material was administered, slight peripheral enhancement was seen in three patients (75%). Conclusion: The common CT findings of metastatic angiosarcoma in our series were multiple hypoattenuating lesions often associated with nodular enhancement and cystic lesions with hemorrhagic change.

OBJECTIVE. The purpose of our study was to summarize the CT features of pulmonary metastases in angiosarcoma in 24 patients.CONCLUSION. A variety of CT features were associated with metastatic angiosarcoma of the lung. The common CT manifestations of metastatic angiosarcoma were multiple solid nodular lesions and multiple thin-walled cysts that were often accompanied by hemorrhagic change.

Recently, CT colonography has been recognized as an effective option for evaluating colorectal polyps in the USA. We have applied this technique to preoperative staging of colorectal cancer patients with a contrast-enhanced multi-detector row CT (MDCT). The use of manipulated multi-planar reconstruction (MPR) views in contrast-enhanced MDCT colonography proved advantageous for detecting lymph node metastases. Furthermore, 3-dimensional (3D) endoluminal images with Hansfield-transparency settings allowed vascular views of the colorectal wall for identification of invasive colorectal cancers. Using endoluminal images, increase in flow and pooling of blood related to angiogenesis of invasive cancer could be demonstrated, not only in the lymph nodes but also in the colorectal wall. Both MPR views and 3D endoluminal images can be acquired from the same 3D volumetric data generated by helical scanning in MDCT colonography, and both have great potential as modalities for computer-aided diagnosis (CAD) using blood flow information. Therefore the use of CAD can be expected to improve radiologists' diagnostic performance with regard to colorectal cancer.

The radiology consultation section provides an online consultation service and a cancer image reference database (NCC-CIR). A. Radiology consultation service In October 2006, we started diagnostic radiology consultation in order to improve the quality of diagnosis based on medical images. So far, we have received over 500 requests from radiologists throughout Japan. Ninety-three consultation reports have been put together for requests mainly from the Kanto and Kyushu regions in 2013. Hepato-biliary-pancreatic, musculoskeletal, and lung lesions were the most common subjects. Consultation with a specialist was the most frequent reason for consultation (37.9%), followed by difficulty with diagnosis (37.0%), and confirmation of a clients' diagnosis (8.4%). Client radiologists have evaluated 314 (91.0%) of the 345 consultation reports as having a useful clinical impact on the final radiological diagnoses. We started the selection of educational consultation cases into NCC-CIR. B. NCC-CIR The NCC-CIR is a web-based reference database system comprising images of neoplasms for physicians, radiologists, and pathologists, providing medical diagnostic images and information together with the pathology. The average number of effective accesses to this site was almost the same as that in 2008-2013, i.e. about 100,000 per month. In 2013, cases of cancer for which interventional radiology was performed (n = 11), head and neck cancers (n = 8), musculoskeletal malignancies (n = 7), lung cancers (n = 5), and other cancers were published, resulting in provision of a total of 284 cases. C. Support for clinical trials We are currently trying to reconstruct the consultation system to make it more suitable for supporting central radiological review in clinical trials, radiological diagnosis, and assessment of changes in tumor burden. We are also investigating ways of improving the system for sending and receiving digital imaging files more easily and quickly using a teleradiology system.

We assessed the local recurrence rate after a single targeted transarterial oily chemoembolization for small hepatocellular carcinoma with the unified helical CT and angiography system and analyzed the factors affecting the local recurrence rate and survival rate with Cox proportional hazards model.For 54 consecutive patients with 71 small hepatocellular carcinomas (or = 5 cm) with no more than two associated lesions, targeted oily chemoembolization was performed with an emulsion of doxorubicin hydrochloride mixed with iodized oil or a suspension of zinostatin stimalamer followed by gelatin sponge particles. When local recurrence or a new lesion appeared, follow-up targeted oily chemoembolization was performed.For 52 of 71 lesions, the catheterization to a subsegmental or more distal feeding artery could be performed. Local recurrence was recognized in 33.2% at 1 year and 37.8% at 2 and 3 years. The significant factors that affected local recurrence were tumor size (p = 0.005) and degree of deposition of iodized oil within the lesion (p = 0.049). The survival rates at 1, 2, and 3 years were 93.3%, 77.1%, and 77.1%, respectively. The significant factors affecting survival rate were tumor thrombus in large vessels (p = 0.0001), appearing after the first chemoembolization, and maximum tumor size (p = 0.022).Single targeted transarterial oily chemoembolization with the unified helical CT and angiography system had a low local recurrence rate for small hepatocellular carcinoma, and follow-up embolization resulted in a good survival rate. Tumor size along with degree of intratumoral iodized oil deposition and tumor thrombus along with maximum tumor size were significant factors affecting local recurrence and survival rate, respectively.

Anesthetic management of retinoblastoma patients is unremarkable in most cases. Patients are most often babies and laryngoscopic procedures for intubation are usually easy. However, we recently experienced two cases with retinoblastoma with whom tracheal intubation was accomplished with difficulty. We report the two cases with a review of all 5-year records of retinoblastoma (rbl) in our institution. The cases we experienced recently were all patients with rbl with deletion of the long arm of thirteenth chromosome (13q-). In the 5-year review, the incidence of the difficult intubation was significantly higher (P < 0.05) in rbl with 13q- (4/11) than in rbl without 13q- (0/147). In our experience macroglossia was noted for the difficulty in the intubation. We assume that some patients with rbl will be cases of difficult intubation even to cannot ventilate-cannot intubate level when the results of their chromosomal analysis show a deletion on the thirteenth chromosome.

A 44-year-old woman presented with a right huge axillary mass. Both mammography and ultrasonography revealed a primary cancer of 2.8 cm maximum diameter in the right breast and metastases in the axillary lymph nodes, both being confirmed by aspiration cytology as ductal carcinoma. Right standard radical mastectomy with level III axillary lymph node dissection was carried out. Pathologically, the tumor was diagnosed as ductal carcinoma in situ with microinvasion (DCISM), histologic grade 3. The area of stromal invasion measured 1 mm at its widest point. Sixteen of the 17 resected axillary lymph nodes contained metastases, including six level III lymph nodes. Immunohistochemical studies of the tumor revealed overexpression of p53 protein, but not that of c-erbB-2 protein. The frequency of lymph node metastases from DCISM is reported to be very low. Therefore, the present case with extensive involvement of level III lymph nodes was unusual.

The purpose of this study was to investigate technetium-99m pertechnetate (Tc-99m) as a tumor-scanning agent in patients with extra-abdominal fibromatosis, and to establish the sensitivity of this type of scintigraphy. Eleven patients with extra-abdominal fibromatosis were studied: all but one having postsurgical recurrences. Of the 11 patients, diagnosed histologically, 5 underwent repeated Tc-99m scintigraphic follow-up examinations. The injected 370 MBq Tc-99m gave us an early scintigram within 10 min and a delayed one 2 h later. For adequate comparison, the region of interest (ROI) of the scintigram was placed over the tumor. The tumor-to-background (T/BG) count ratio was computed. Extra-abdominal fibromatoses, even recurrences, were demonstrated scintigraphically in both the early and the delayed phase, in all 11 patients. The average T/BG ratio was 2.11 in the early scintigram and 2.15 in the delayed one. The sensitivity and the specificity were both 100%. Tc-99m scintigraphy has proved useful in detecting extra-abdominal fibromatoses and in the follow-up of patients.

The purpose of this study was to determine the sensitivity of CT in detecting early hepatocellular carcinoma and to evaluate its CT appearance. An early hepatocellular carcinoma is a nodular lesion with no fibrous capsule composed of well-differentiated tumor histologically. It differs from a small hepatocellular carcinoma, which is an overt tumor that is moderately to poorly differentiated and has a fibrous capsule. Size is not a criterion for distinguishing between early and small hepatocellular carcinomas.Thirty-one patients with 39 histopathologically proved early hepatocellular carcinomas (mean diameter, 1.7 cm) found by sonography, MR imaging, and/or intraoperative sonography were included in a retrospective study. We reviewed unenhanced CT scans of the entire liver in 30 patients (37 lesions) and early and late (35 sec and 5 min after the beginning of injection of contrast material) contrast-enhanced CT scans of the entire liver in all 31 patients (table incremental CT in 21; helical CT in 10; 39 lesions). Eighteen histologically proved small hepatocellular carcinomas (or = 3 cm; mean diameter, 2.3 cm), present in the same patients, served for comparison. Histopathologically, nine patients had chronic hepatitis, and 22 had cirrhosis.The overall sensitivity of CT in detecting early hepatocellular carcinoma was 56%. These tumors were usually isodense with respect to surrounding liver on unenhanced, early enhanced, and late enhanced CT scans (iso-iso-iso). This pattern was seen in 17 (46%) of 37 lesions; thus, these 17 histologically proved early hepatocellular carcinomas were not detected with CT. An iso-iso-low density pattern was recognized in eight (22%), a low-low-low pattern in seven (19%), and several different patterns in five (13%) of the 37 lesions. Only two (5%) of 39 early hepatocellular carcinomas had a high-density appearance on early enhanced CT scans. In comparison, the most common pattern of small overt hepatocellular carcinomas on CT scans was low-high-low, seen in 17 lesions (94%) detected with CT. When the density of lesions on unenhanced CT scans was compared with the histopathologic appearance of the masses, low-density lesions showed mild to moderate fatty change and isodense lesions showed no or minimal fatty change (p = .006).The sensitivity of CT in detecting early hepatocellular carcinoma is poor (56%). However, the diagnosis of early hepatocellular carcinoma should be considered if CT scans show a small lesion with an iso-low or low-low density enhancement pattern on early and late contrast-enhanced CT scans, respectively, in patients with chronic liver disease.

To use computed tomography (CT) during arterial portography (CTAP) and CT arteriography to compare the hemodynamic properties of early hepatocellular carcinoma (HCC) with those of small HCC.Forty-four early HCCs (mean diameter, 1.5 cm) in 37 patients (26 men and 11 women aged 52-74 years; mean age, 59.2 years) were studied. CTAP was performed on 35 early HCCs, CT arteriography on 20, and both studies on 11. CTAP, CT arteriography, or both were performed on 90 small HCCs (mean diameter, 2.0 cm) in 57 patients (44 men and 13 women aged 48-71 years; mean age, 61 years). The findings for small HCC were compared with those for early HCC.CTAP depicted 23 early HCCs as hypoattenuating masses and 12 as isoattenuating. CT arteriography depicted 11 early HCCs as hypoattenuating masses, six as isoattenuating, and three as hyperattenuating. CTAP depicted 85 of 88 small HCCs as hypoattenuating masses and three as isoattenuating. CT arteriography depicted 13 of 14 small HCCs as hyperattenuating masses.CTAP, the standard of reference for the detection of small HCC, is not sensitive enough for the detection of early HCC.