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DOI： 10.3390/diagnostics11071267

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DOI： 10.1093/jrr/rraa029

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DOI： 10.1259/bjr.20190712

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DOI： 10.1007/s11604-019-00826-2

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DOI： 10.1007/s12282-018-0899-8

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DOI： 10.2463/mrms.mp.2015-0171

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DOI： 10.2463/mrms.mp.2015-0065

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A 34-year-old woman with a past history of a carcinoid tumor in the right ovary presented with a right breast mass found on contrast-enhanced computed tomography (CT) of the chest. She was asymptomatic, and her blood tests were normal. The mass measured about 2 cm. Mammography showed a lobular, circumscribed, high-density mass without microcalcifications in the upper outer quadrant of the right breast. Ultrasonography showed an irregular mass with both hypoechoic and hyperechoic components with increased vascularity. The mass was well enhanced on contrast-enhanced CT and dynamic magnetic resonance imaging. At the same time, a well-enhanced small nodule was detected in the pouch of Douglas. Both of the tumors were resected, and a primary breast neuroendocrine tumor (solid neuroendocrine carcinoma) and peritoneal dissemination of the ovarian carcinoid tumor were diagnosed.

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RVS(Real-time Virtual Sonography)は、取得しておいたCTデータからUS走査に同期させてCTMPR画像を並列描画させるシステムである。乳腺の画像診断における有用性が高く、従来同定できなかった乳癌の検出に有効的新技術と考える。

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OBJECTIVE: The objective of our study was to assess whether it is possible to reduce the dose and rate of contrast material injection in elderly patients in triple-phase contrast-enhanced CT of the pancreatobiliary region with an MDCT scanner. SUBJECTS AND METHODS: One hundred twelve patients were divided into three groups: contrast injection at 0.08 mL/kg body weight/s (an upper limit of 5 mL/s) over 30 seconds in patients 60 years old or younger (group 1, n = 49), the same contrast injection as group 1 in patients more than 60 years old (group 2, n = 32), and contrast injection at 0.07 mL/kg body weight/s (an upper limit of 4.5 mL/s) over 30 seconds in patients more than 60 years old (group 3, n = 31). Contrast enhancement in the aorta, portal venous system, pancreas, and liver was assessed quantitatively. Two radiologists blinded to the patients' clinical information and the injection protocol used to acquire the CT images graded the degree of contrast enhancement using a 5-point scoring system. The results for the different groups were statistically compared. RESULTS: Contrast enhancement in the main phases for all organs was significantly more intense in group 2 than in groups 1 and 3. Cases in which pancreatic enhancement in the pancreatic phase was graded as excessive were more frequently observed in group 2. No statistically significant differences were observed between groups 1 and 3 in either quantitative or visual assessment for enhancement of any organ in any phase. CONCLUSION: We recommend reducing the dose and rate of contrast material injection by at least 10% for elderly patients undergoing MDCT examination of the pancreatobiliary region.

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OBJECTIVE: The objective of our study was to assess the capabilities of MDCT for the diagnosis of an anomalous pancreaticobiliary ductal junction using high-resolution multiplanar reformatted (multiplanar reconstruction) images. MATERIALS AND METHODS: This study included nine patients with and 54 without an anomalous pancreaticobiliary ductal junction confirmed on direct cholangiopancreatography. Multiplanar reconstruction images with 0.5-mm continuous slices were generated from isotropic or nearly isotropic pancreatic phase images. By mainly interpreting the multiplanar reconstruction images using the Scrolling mode, two blinded reviewers independently determined whether the confluence of the pancreatic and biliary ducts joined in the pancreatic parenchyma (in other words, outside the duodenal wall). The results were correlated with the findings of direct cholangiopancreatography. The diagnostic capabilities of CT for revealing associated pancreatobiliary diseases were assessed in patients with this anomaly. RESULTS: Interobserver agreement in the classification of the duct confluence was high (kappa = 0.804). The duct confluence was identified in all patients except four without an anomalous pancreaticobiliary ductal junction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of CT for diagnosing an anomalous pancreaticobiliary ductal junction were 100% (9 of 9 patients), 87% (47 of 54 patients), 89% (56 of 63 patients), 75% (9 of 12 patients), and 100% (47 of 47 patients) in the final decisions, respectively. CT showed all associated pancreatobiliary diseases except bile duct stones in two patients. CONCLUSION: MDCT enabled the diagnosis of an anomalous pancreaticobiliary ductal junction by showing whether the pancreatic and biliary ducts join within the pancreatic parenchyma on high-resolution multiplanar reconstruction images.

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Language：Japanese   Publishing type：Research paper (scientific journal)  

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The object of this study was to evaluate the usefulness of high-resolution multiplanar reformatted (MPR) images obtained by multislice CT in demonstrating connection between pancreatic cystic lesions and the main pancreatic duct. The study included 27 lesions with connection to the main pancreatic duct and 12 lesions without. All but one of the former lesions were branch duct-type intraductal papillary mucinous tumors (IPMTs). Oblique and curved MPR images with 0.5 mm continuous slices were generated from pancreatic-phase axial images reconstructed with 0.5 mm or 1 mm thickness at 0.5 mm intervals over a 260 mm field of view. The diagnostic capabilities for demonstrating connection with the main pancreatic duct were compared among axial images, MPR images, and both axial and MPR images in combination using the Brier score. The diagnosis in MPR images for demonstrating connection was more certain than that in axial images (P<0.05). Compared with MPR images alone, the use of both axial and MPR images resulted in further improvements in diagnostic performance, although the difference was not statistically significant. The use of high-resolution MPR images significantly improves diagnostic performance for demonstrating connection between pancreatic cystic lesions and the main pancreatic duct, which is useful for the diagnosis of branch duct-type IPMT.

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PURPOSE: To determine whether or not high-concentration contrast material is useful in multiphase contrast-enhanced CT of the liver with a multislice CT scanner. MATERIALS AND METHODS: One hundred twenty-four examinations, in which first- and second-pass acquisitions (double arterial phase imaging) were performed during a single breath-hold followed by third-pass acquisition, were randomized into three protocols: contrast injection at 0.07 mL/kg body weight/sec over 30 sec at an iodine concentration of 300 mgI/mL in group 1, contrast injection at 0.06 mL/kg body weight/sec over 30 sec at an iodine concentration of 350 mgI/mL in group 2, and contrast injection at 0.07 mL/kg body weight/sec over 25.7 sec at an iodine concentration of 350 mgI/mL in group 3. Each group received an equivalent iodine dose per kg body weight (2.1 mL/kg of contrast material of 300 mgI/mL). Contrast enhancement in each acquisition was measured in the aorta, portal vein, and liver. RESULTS: No statistically significant differences were seen between groups 1 and 2 in any enhancement in any acquisition. In group 3, aortic enhancement in the first-pass acquisition was significantly more intense than in groups 1 and 2, while portal venous enhancement and hepatic enhancement were equivalent. CONCLUSION: Shortening the injection duration for a given iodine dose with high-concentration contrast material (group 3) can achieve improved arterial enhancement on arterial phase images.

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Language：English   Publishing type：Research paper (scientific journal)  

PURPOSE: To evaluate the usefulness of multi-slice computed tomography (MSCT) in comparison with ultrasonography (US) for the differentiation of benign from malignant thyroid nodules and the evaluation of tumor extension. MATERIALS AND METHODS: Thirty patients with thyroid nodules (14 malignant, 16 benign) who underwent both MSCT and US participated in the present study. MSCT with contrast enhancement was performed, and 3D shaded volume rendering (SVR) and multiplanar reconstruction (MPR) were employed to differentiate benign from malignant nodules and to evaluate tumor extension. US images were obtained using a 7.5 MHz annular array probe. A three-point rating scale was used for image interpretation, and the kappa statistic was employed to evaluate agreement between MSCT and US. RESULTS: Sensitivity in differentiating benign from malignant nodules was found to be 85.7% for US and 78.6% for MSCT. Disagreement between MSCT and US occurred in assessing the homogeneity of the solid component and the presence of fibrous capsule. In two of seven T4 cases, MPR provided a more accurate diagnosis than US examination in detecting extracapsular invasion. CONCLUSION: For differential diagnosis of thyroid nodules, US was found to be better than MSCT. However, MSCT could be useful for the evaluation of advanced cases with suspicion of extracapsular extension.

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The value of automatic bolus tracking in late-arterial and portal-venous phase imaging of the liver with a multislice CT scanner as compared with fixed time-delay examination in patients without circulatory disturbances is evaluated. For the evaluation of known or suspected liver disease, 98 multiphase contrast-enhanced CT examinations including double late-arterial phase imaging were randomized into either scanning with a scan delay of 30 s from the beginning of contrast material injection or scanning with automatic bolus tracking. Contrast material was injected at 0.07 ml/kg body weight/s over 30 s. Contrast enhancement in each acquisition was measured in the aorta, portal vein, liver, pancreas and hepatocellular carcinomas. The density difference between hepatocellular carcinomas and the hepatic parenchyma was calculated. The mean time to the first-pass acquisition as determined by automatic bolus tracking was 29.6 s. No statistically significant difference was observed between the two groups either in any enhancement in any acquisition or in the lesion-to-liver density difference. The use of automatic bolus tracking in late-arterial and portal-venous phase hepatic CT does not significantly improve the degree of contrast enhancement in the aorta, portal vein, liver and pancreas or lesion-to-liver conspicuity in patients without circulatory disturbances.

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Language：English   Publishing type：Research paper (scientific journal)  

PURPOSE: To evaluate the accuracy of CT images of abdominal aortic aneurysm (AAA) with volume-rendered (VR) display of vessel lumen and thrombus and to evaluate its usefulness in the planning of stent-grafting. MATERIALS AND METHODS: Helical CT was performed in 11 patients with AAA. Volume data of the vessel lumen and thrombus were separately extracted, and the VR images were reconstructed. Vessel measurements were made by five radiologists and compared with the axial and multiplanar reconstruction (MPR) images. Angiography and intravascular ultrasonography were used as standard references. The relations of aneurysmal sac to the major arterial branches and the subjective overall diagnostic value were evaluated by using a continuous rating scale. RESULTS: Accuracy of measurements was higher on VR images than on axial/MPR in 7 of 13 regions. Interobserver variance of VR images was smaller in 7 of 14 regions. Detection of renal and internal iliac artery involvements was better on VR images (p<0.05). Overall diagnostic value was also higher on VR images (p<0.05). CONCLUSION: VR CT images of vessel lumen and thrombus are supportive of and supplementary to conventional axial/MPR images in planning stent-grafting for AAA.

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PURPOSE: To determine whether employing a method for changing the tube current during helical scanning helps to adapt the image noise among various sections of the upper abdomen and chest in multislice computed tomography (CT). MATERIALS AND METHODS: One hundred CT examinations of the upper abdomen were assigned to one of two scanning protocols: standard scanning with a constant tube current and scanning with the changing method based on protocol 1. One hundred fifty CT examinations of the chest were assigned to one of three protocols: standard scanning with a constant tube current and scanning with the changing method based on protocols 1 and 2. In protocol 1, the tube current for each rotation was reduced in proportion to the water equivalent thickness based on the rotation showing the maximum value, while, in protocol 2, the tube current was increased in proportion to the water equivalent thickness based on the rotation showing the minimum value. The mean tube current, mean standard deviations (SDs) of the measured CT numbers, and dispersion of the SDs were compared between the different protocols. RESULTS: In the upper abdomen, the use of the changing method based on protocol 1 resulted in a significant reduction in the dispersion of the SDs of CT numbers, with no increase in mean tube current or mean SDs. In the chest, use of the changing method based on protocol 2 resulted in a significant reduction in the dispersion of the SDs of CT numbers, with a reduction in mean tube current and no increase in mean SDs. CONCLUSION: The method for changing tube current during helical scanning makes it possible to adapt the image noise among various sections of the upper abdomen and chest without increasing dose in multislice CT.

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Our objective was to evaluate the ability of multiplanar reformatted (MPR) images combined with 0.5-mm axial images to depict the pancreatic and intrapancreatic bile ducts and compare the results with those of 0.5-mm axial, 2-mm axial, and 6-mm axial images alone. Seventy-seven patients without obstruction of the main pancreatic ducts (MPD) underwent dual-phase helical scanning of the pancreas using multislice computed tomography (MSCT). The MPR images were generated from 0.5-mm-thick images. Visualization of the pancreatic and intrapancreatic bile ducts and their confluence was graded on a four-point scale by a consensus of two radiologists. The results for 0.5-mm axial images in early-phase CT, 2-mm axial images in early-phase CT, MPR images combined with 0.5-mm axial images in early-phase CT, and 6-mm axial images in late-phase CT were then compared. The relationships of the focal pancreatic lesions with the pancreatic ducts were analyzed. The MPR images combined with 0.5-mm axial images were significantly superior to the other three types of images for the visualization of the pancreatic and intrapancreatic bile ducts and their confluence (p<0.01). The depiction rate of the MPD using MPR images combined with 0.5-mm axial images was 94, 94, 95, and 75%, respectively in the head, neck, body, and tail of the pancreas. Accessory pancreatic ducts, intrapancreatic bile ducts, and duct confluence were depicted in 48, 99, and 92%, respectively. In comparison with evaluation based on axial images alone, the use of MPR images more clearly demonstrated the relationship between the lesions and the pancreatic ducts in 14 of 19 lesions. The MPR images combined with 0.5-mm axial images improve the CT depiction of the pancreatic and intrapancreatic bile ducts in comparison with 0.5-mm axial, 2-mm axial, and 6-mm axial images alone.

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Our objective was to assess the effects of the injection rate of contrast material and of a 5% dextrose flush on enhancement in multiphase hepatic CT using a multislice CT scanner. Most patients had chronic hepatitis and/or liver cirrhosis. One hundred eighty examinations, in which two sequential acquisitions were performed during a single breath-hold followed by third- and fourth-pass acquisitions, were randomized into four protocols: contrast injection at 0.1 ml/kg body weight s(-1) over 21 s without and with a 30-ml flush in groups 1 and 2, respectively, and contrast injection at 0.07 ml/kg body weight s(-1) over 30 s without and with a flush in groups 3 and 4, respectively. Contrast enhancement in each acquisition was measured in the aorta, portal vein, and liver. The visualization of hepatic arterial branches was scored by visual assessment. The highest aortic enhancement was observed in the first-pass acquisition in all groups. At the higher injection rate (groups 1 and 2), aortic enhancement in the first-pass acquisition was significantly more intense, whereas portal venous and hepatic enhancement was significantly less intense. The use of a flush considerably improved aortic enhancement at the beginning of the second-pass acquisition. In the visual assessment of hepatic arterial branches, the protocols with the higher injection rate received significantly higher grades. Multislice CT permits the entire liver to be imaged during an almost exclusively arterial phase by shortening the injection duration for a given volume of contrast material.

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PURPOSE: The aim of this study was to assess the impact of preoperative magnetic resonance mammography (MRM) on the surgical determination of breast conservation treatment for breast cancer patients. METHODS: From September 1997 to March 2000, 57 consecutive breast conservation treatment candidates were prospectively evaluated with conventional imaging studies (mammography and ultrasonography) and preoperative MRM. RESULTS: In 47 of 54 (87% ) breast cancer patients breast conservation surgery (BCS) was indicated on the basis of mammography (MMG) and ultrasonography (US). However in 40 of the 54 (74% ) patients BCS was indicated on the basis of MRM. Thirty-eight of the 40 patients ultimately underwent BCS and only 1 showed a positive margin. There were 7 patients whose MRM findings suggested that more aggressive treatment than BCS was needed but for whom US/MMG suggested that BCS was appropriate. Five of the 7 patients underwent mastectomy rather than BCS based on the MRM findings, which were justified by post-surgical histological findings. Of the 2 remaining patients who underwent BCS, one had a positive histological margin and one had recurrence, both of which resulted in salvage mastectomy. CONCLUSION: Our study suggests that high resolution preoperative MRM provides more accurate information compared with US and MMG for selecting candidates for BCS. Using MRM as a routine staging tool may reduce unnecessary repeated excisions. A larger study will be required to confirm these findings and to define the patients most likely to benefit from breast MR imaging.

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PURPOSE: To clarify the CT characteristics and histopathological findings of pancreatic ductal adenocarcinomas that are not detected in early-phase contrast-enhanced CT images. MATERIALS AND METHODS: The CT findings of eight patients with histopathologically proven pancreatic carcinomas that were not detected in early-phase images following the rapid injection of contrast material were reviewed. The examinations consisted of pre-contrast-enhanced CT and multi-phase contrast-enhanced CT, with thin-section scanning in each patient. The CT findings were compared with those of the resected specimens. RESULTS: In all cases but one, the lesion was in the pancreatic head. In seven cases, the tumor did not appear as a focal area of hypoattenuation compared with surrounding pancreatic parenchyma in early-phase images, and in the remaining case, small areas of poor enhancement were observed. In late-phase images, hyperattenuated and isoattenuated areas were seen in six and two cases, respectively. In all but one case, the lesion was less than 40 mm in size. All lesions were composed of acinar tissues and tumor cells, and contained small amounts of mucin, necrotic tissue, and pus. The fibrous tissues were not abundant and were interlobular and/or relatively loose. CONCLUSION: Pancreatic ductal adenocarcinomas showing isoattenuation in early-phase images tend to be relatively mild lesions with scirrhous and/or desmoplastic changes.

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Our objective was to evaluate interobserver agreement and to compare the performance score in quality control of screen-film mammography and computed radiography (CR) using a breast phantom. Eleven radiologists interpreted a breast phantom image (CIRS model X) by four viewing methods: (a) original screen-film; (b) soft-copy reading of the digitized film image; (c) hard-copy reading of CR using an imaging plate; and (d) soft-copy reading of CR. For the soft-copy reading, a 17-in. CRT monitor (1024x1536x8 bits) was used. The phantom image was evaluated using a scoring system outlined in the instruction manual, and observers judged each object using a three-point rating scale: (a) clearly seen; (b) barely seen; and (c) not seen. For statistical analysis, the kappa statistic was employed. For "mass" depiction, interobserver agreement using CR was significantly lower than when using screen-film ( p<0.05). There was no significant difference in the kappa value for detecting "microcalcification"; however, the performance score of "microcalcification" on CR hard-copy was significantly lower than on the other three viewing methods ( p<0.05). Viewing methods (film or CR, soft-copy or hard-copy) could affect how the phantom image is judged. Paying special attention to viewing conditions is recommended for quality control of CR mammograms.

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A method for changing the tube current during helical scanning was applied to low-dose computed tomography (CT) in the lung. The changing method resulted in significant equalization of image noise in various lung sections compared with that at scanning with constant tube current. Detectability of nodules was equivalent between 60 mA and the changing method, whereas degradation occurred at 20 mA. This method seems feasible for the low-dose CT of lung cancer screening.

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Eight radiologists interpreted body CT images of 30 cases using a viewing station (six 17-in. monitors, 1024x1280). Using two different display methods, 'zoom-and-pan' and 'browse-and-paste', the readers described the presence or absence of liver tumors using a five-point rating scale and temporal changes between the current and previous studies using a seven-point rating scale. There was no significant difference in kappa values for tumor detection between the two display modes. However, in describing temporal changes, the kappa value of the browse-and-paste was significantly lower than that of zoom-and-pan (p<0.01). Browse-and-paste may have the disadvantage of greater interobserver variation.

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The purpose of this study was to assess the role of US in the detection of intraductal spread of breast cancer in comparison with mammography (MMG) and MRI. In 46 patients with breast cancer, US features of the intraductal component were classified as ductal type or distorted type. Histopathologically, 29 of 46 (63%) cases had intraductal components, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 89, 76, and 85%, respectively. Each US pattern demonstrated good correspondence to the histologic components, and the distorted type correlated well with comedo-type carcinoma. Mammography was performed in all cases, and the sensitivity, specificity, and accuracy rates in detection of intraductal spread were 55, 100, and 72%, respectively. In comedo type, MMG could diagnose the extent of intraductal spread more accurately compared with US examination. Magnetic resonance imaging comparison was available in 25 cases. Magnetic resonance imaging depicted intraductal extension as an enhanced area during the early phase of a contrast enhancement study with a sensitivity of 93%. Ultrasound and MRI were closely related in terms of morphologic characteristics: the ductal type of US image correlated well with linear enhancement on MRI, whereas the distorted type correlated with regional or segmental enhancement. Current US examination is useful in depicting the intraductal spread of breast cancer; however, US has a tendency to underestimate intraductal component of comedo type compared with MMG and MRI.

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We have developed a computer-aided diagnostic (CAD) system using fuzzy inference for breast sonography and have evaluated the performance of the system. Our CAD system is not an automated image processing method, but requires the observer's subjective "scoring." Seven radiologists interpreted 54 breast mass lesions (24 malignant, 30 benign). Six criteria (shape, border, halo, internal echoes, posterior echoes, and edge shadows) were scored using a five-point rating scale. The output was described as a real number from 0.0 to 1.0. For cancer diagnosis, the sensitivity of the radiologists, a six-criteria CAD version, and a four-criteria version (excluding posterior echoes and edge shadows) were 63.1%, 82.1%, and 78.0%, respectively. Specificity was 71.0%, 42.9%, and 51.0%, respectively, while accuracy was 67.5%, 60.3%, and 63.0%, respectively. No significant differences in the areas under ROC curve (Az) were found between the observers and CAD system. Several cases assessed as false-negative by observers were correctly diagnosed by the CAD system, and diagnostic efficacy could be improved, especially among novice sonographers. Although the system's high false-positive rate needs to be reduced, it will assist radiologists in generating a level of suspicion for malignancy.

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OBJECTIVE: To evaluate interobserver agreement in the interpretation of breast ultrasonography. METHODS: 55 breast masses (30 benign, 24 malignant) were interpreted by seven radiologists using a CRT viewing station. US criteria for differentiating between benign and malignant lesions included shape, border, boundary echoes, internal echoes, posterior echoes, and bilateral shadows. Each criterion and the observers' final impression was scored using the 5-point rating scales. For analyzing interobserver agreement, the kappa (kappa) values were employed. RESULTS: The kappa values of shape and posterior echoes were significantly higher than those of the other four criteria (P<0.05). Agreement was intermediate in border and internal echoes, and was low in boundary echoes and bilateral shadows. Agreement in the senior group (four observers) was relatively higher than that in the junior group (three observers) for all criteria but for internal echoes. Easily-diagnosed cases showed significantly higher kappa values compared with more ambiguous cases (P<0.05). CONCLUSION: Interobserver agreement in shape and posterior echoes was significantly higher than those of the other four criteria. Agreement was significantly dependent on case difficulty.Copyright 1998 Elsevier Science Ireland Ltd.

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OBJECTIVE: To evaluate the usefulness of ultrasonography including Doppler flow imaging for the preoperative staging of thyroid papillary carcinoma. MATERIALS AND METHODS: In 77 patients with thyroid papillary carcinoma who underwent total thyroidectomy, the accuracy of ultrasonography in preoperative clinical staging was assessed with use of pathologic examination on the basis of TNM classification by the International Union Against Cancer (UICC). RESULTS: In 63 (81.8%) cases, T categories were estimated accurately. The sensitivity in depicting tumor extension into the prethyroidal muscle and/or the sternocleidomastoid muscle was 77.8%, whereas the sensitivity for invasion into the trachea and the esophagus was 42.9 and 28.6%, respectively. In 37 (48.1%) cases, N categories were underestimated, and the sensitivity in the detection of regional lymph node metastasis was 36.7%. Doppler flow imaging was performed in 36 patients, and no correlation was found between flow patterns and the presence of local invasion or regional lymph node metastasis. CONCLUSION: Ultrasonography was useful for preoperative investigation of thyroid papillary carcinoma, but several limitations existed, especially in evaluating extracapsular invasion to deep locations and regional lymph node metastasis.

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The detectability of various abnormal findings in helical screening CT(HSCT) with low-dose and single-breath-hold scanning of the lung was examined using conventional CT as a gold standard. In 75 patients, HSCT was obtained with scanning parameters of 120kVp, 50 mA, 10 mm-collimation. 20 mm/second and 1 sec/rotation. Conventional CT was obtained with 150 mA and 10 mm-slice contiguous scanning HSCT depicted 141 of 159 focal lesions in nodules and masses (65 of 69 lesions more than 5mm in size), 44 of 47 in infiltrative lesions, 11 of 11 in reticular lesions and 23 of 39 in bullae and blebs. There were only 3 false positive lesions in nodule and mass. Sensitivity, specificity and accuracy of HSCT for diffuse lesions were 100% (11/11), 95% (61/64) and 96% (72/75) for fibrotic change and 75% (9/12), 100% (63/63) and 96% (72/75) for emphysematous change, respectively. Since the detectability of HSCT was good for abnormal findings, showing increased attenuation in comparison with the lung parenchyma, it was considered to be a promising method for lung-cancer screening.

Language：English   Publishing type：Research paper (scientific journal)  

In order to develop ultra-low-dose helical CT for lung cancer screening, the effect of reduction of the tube current to 20mA and application of a 10mm thick aluminium filter upon radiation dose and image quality was evaluated with a phantom. Exposure dose at the center of a gantry and absorbed dose at the center of an acrylic phantom at 20mA with the filter were 15% and 29% of the dose at 50mA without the filter, respectively. For reduction of absorbed dose, reduction of the tube current was more useful than application of the filter. Image noise at 20mA with the filter was double that at 50mA without the filter. Neither reduction of the tube current nor application of the filter changed full width at half maximum on section sensitivity of the Z-axis. Although reduction of the tube current did not affect the difference in CT values between an acrylic sphere and styroform, application of the filter caused a reduction of 4.5% in the difference in CT values. Neither reduction of the tube current nor application of the filter affected the contrast resolution of the high-contrast phantom; however, that of the low-contrast phantom deteriorated. Although improvement of the filter and evaluation of clinical images are necessary, reduction of the tube current to 20mA and application of the aluminium filter appear to be a promising method for ultra-low-dose helical CT of the lung.

Responsible for pages：118-137   Language：Japanese

Responsible for pages：40-45   Language：Japanese

Event date： 2020.5 - 2020.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Web 「Cypos」やオンデマンド配信   Country：Japan  

Event date： 2020.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2019.9

Language：Japanese  

Venue：熊本   Country：Japan  

Event date： 2019.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2019.2 - 2019.3

Language：English   Presentation type：Poster presentation  

Venue：Wien, Austria   Country：Austria  

Event date： 2019.1

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

Event date： 2019.1

Language：Japanese  

Venue：長崎   Country：Japan  

Event date： 2018.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Chicago, USA   Country：United States  

Event date： 2018.10

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2018.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2018.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2018.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2017.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2017.11 - 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Chicago, USA   Country：Japan  

Event date： 2017.11 - 2017.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Chicago, USA   Country：United States  

Event date： 2017.9

Language：Japanese   Presentation type：Poster presentation  

Venue：松山   Country：Japan  

Event date： 2017.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2017.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2017.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：博多   Country：Japan  

Event date： 2017.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2017.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2017.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2017.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2017.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2017.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岐阜   Country：Japan  

Event date： 2017.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2016.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2016.4

Language：English   Presentation type：Poster presentation  

Country：Japan  

Event date： 2016.4

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2016.3

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2016.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2016.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：山形   Country：Japan  

Event date： 2015.11

Language：English   Presentation type：Oral presentation (general)  

Venue：Fukuoka, Japan   Country：Japan  

Event date： 2015.10

Language：English   Presentation type：Poster presentation  

Venue：San Antonio, USA   Country：United States  

Event date： 2015.9

Language：Japanese  

Venue：東京   Country：Japan  

Event date： 2015.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸   Country：Japan  

Event date： 2015.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜   Country：Japan  

Event date： 2014.11 - 2014.12

Language：English   Presentation type：Poster presentation  

Country：United States  

Event date： 2014.10

Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

Venue：東京   Country：Japan  

Event date： 2014.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2014.9

Language：Japanese  

Venue：京都   Country：Japan  

Event date： 2014.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2014.7

Language：Japanese  

Venue：大阪   Country：Japan  

Event date： 2014.7

Language：Japanese   Presentation type：Symposium, workshop panel (public)  

Venue：大阪   Country：Japan  

Event date： 2013.11 - 2013.12

Language：English   Presentation type：Oral presentation (general)  

Country：United States  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸   Country：Japan  

Event date： 2013.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：徳島   Country：Japan  

Event date： 2013.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市   Country：Japan  

Event date： 2013.4

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2013.2

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2012.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：国立京都国際会館   Country：Japan  

Event date： 2012.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2012.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：神戸市   Country：Japan  

Event date： 2012.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市   Country：Japan  

Event date： 2012.4

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2012.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：横浜市   Country：Japan  

Event date： 2011.12

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都   Country：Japan  

Event date： 2011.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山   Country：Japan  

Event date： 2011.4

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2010.11

Language：English  

Event date： 2010.10

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：鹿児島   Country：Japan  

Event date： 2010.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば市   Country：Japan  

Event date： 2010.7

Language：Japanese  

Country：Japan  

Event date： 2010.6

Language：Japanese  

Country：Japan  

Event date： 2010.6

Language：Japanese  

Country：Japan  

Event date： 2010.6

Language：Japanese  

Country：Japan  

Event date： 2010.5

Language：English  

Event date： 2010.4

Language：Japanese  

Country：Japan  

Event date： 2010.4

Language：Japanese  

Country：Japan  

Event date： 2010.2

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京   Country：Japan  

Event date： 2010.1

Language：Japanese  

Country：Japan  

Event date： 2009.11

Language：English  

Event date： 2009.11

Language：Japanese  

Country：Japan  

Event date： 2009.10

Language：Japanese  

Country：Japan  

Event date： 2009.4

Language：Japanese  

Country：Japan  

Event date： 2009.4

Language：Japanese  

Country：Japan  

Event date： 2009.3

Language：English  

Event date： 2009.2

Language：Japanese  

Country：Japan  

Event date： 2009.2

Language：Japanese  

Country：Japan  

Event date： 2008.9

Language：Japanese  

Country：Japan  

Event date： 2008.9

Language：Japanese  

Country：Japan  

Event date： 2008.9

Language：Japanese  

Country：Japan  

Event date： 2008.6

Language：Japanese  

Country：Japan  

Event date： 2008.4

Language：Japanese  

Country：Japan  

Event date： 2008.4

Language：Japanese  

Country：Japan  

Event date： 2007.5

Language：Japanese  

Country：Japan  

Event date： 2007.4

Language：Japanese  

Country：Japan  

Event date： 2007

Language：Japanese  

Country：Japan  

Event date： 2007

Language：Japanese  

Event date： 2007

Language：Japanese  

Country：Japan  

Event date： 2007

Language：Japanese  

RVS(Real-time Virtual Sonography)は、取得しておいたCTデータからUS走査に同期させてCTMPR画像を並列描画させるシステムである。乳腺の画像診断における有用性が高く、従来同定できなかった乳癌の検出に有効的新技術と考える。

Event date： 2007

Language：Japanese  

Country：Japan  

Event date： 2006

Language：Japanese  

Event date： 2006

Language：Japanese  

Country：Japan  

Event date： 2006

Language：Japanese  

Country：Japan  

石灰化病変に対するモニタ診断の有用性を示唆した研究

Event date： 2006

Language：Japanese  

Country：Japan