Biomedical subjects

Noriyuki Tomiyama

Publications and source records attributed to Noriyuki Tomiyama.

At least 19 recordsLinked to original sources

PubMed2006

Solitary pulmonary metastases from renal cell carcinoma: comparison of high-resolution CT with pathological findings.

PURPOSE: The aim of this study was to examine the radiographic features of solitary pulmonary metastases from renal cell carcinoma by comparing high-resolution CT (HRCT) findings with histopathological observations. MATERIALS AND METHODS: Three thoracic radiologists retrospectively reviewed HRCT findings from eight patients who underwent surgery on the basis of the diagnosis of solitary pulmonary metastatic renal cell carcinoma. The histopathological diagnoses for six of these eight lesions were metastases from clear cell carcinoma of the kidney, one case was a metastasis from papillary renal cell carcinoma, and the remaining case was a metastasis from a poorly differentiated carcinoma including predominantly spindle cells, papillary cells, and clear cells. RESULTS: The HRCT findings of all cases of clear cell carcinoma showed solid nodular lesions without ground-glass attenuation (GGA). The HRCT findings for one case of papillary renal cell carcinoma showed a lobulated nodule with a small amount of GGA in an area in the periphery and an air bronchogram. The HRCT findings of the remaining case of poorly differentiated carcinoma showed an ill-defined nodule with a GGA area and pleural indentations. CONCLUSION: In brief, solitary pulmonary metastases from renal cell carcinoma may present as a smoothly marginated nodule, lobulated nodule, or a nodule with peripheral GGA.

Aged↗

PubMed2006

Computer-assisted lung nodule volumetry from multi-detector row CT: influence of image reconstruction parameters.

PURPOSE: To investigate differences in volumetric measurement of pulmonary nodules caused by changing the reconstruction parameters for multi-detector row CT. MATERIALS AND METHODS: Thirty-nine pulmonary nodules less than 2 cm in diameter were examined by multi-slice CT. All nodules were solid, and located in the peripheral part of the lungs. The resultant 48 parameters images were reconstructed by changing slice thickness (1.25, 2.5, 3.75, or 5 mm), field of view (FOV: 10, 20, or 30 cm), algorithm (high-spatial frequency algorithm or low-spatial frequency algorithm) and reconstruction interval (reconstruction with 50% overlapping of the reconstructed slices or non-overlapping reconstruction). Volumetric measurements were calculated using commercially available software. The differences between nodule volumes were analyzed by the Kruskal-Wallis test and the Wilcoxon Signed-Ranks test. RESULTS: The diameter of the nodules was 8.7+/-2.7 mm on average, ranging from 4.3 to 16.4mm. Pulmonary nodule volume did not change significantly with changes in slice thickness or FOV (p>0.05), but was significantly larger with the high-spatial frequency algorithm than the low-spatial frequency algorithm (p<0.05), except for one reconstruction parameter. The volumes determined by non-overlapping reconstruction were significantly larger than those of overlapping reconstruction (p<0.05), except for a 1.25 mm thickness with 10 cm FOV with the high-spatial frequency algorithm, and 5mm thickness. The maximum difference in measured volume was 16% on average between the 1.25 mm slice thickness/10 cm FOV/high-spatial frequency algorithm parameters and overlapping reconstruction. CONCLUSION: Volumetric measurements of pulmonary nodules differ with changes in the reconstruction parameters, with a tendency toward larger volumes in high-spatial frequency algorithm and non-overlapping reconstruction compared to the low-spatial frequency algorithm and overlapping reconstruction.

Adolescent↗

PubMed2006

Usual interstitial pneumonia and chronic idiopathic interstitial pneumonia: analysis of CT appearance in 92 patients.

PURPOSE: To retrospectively analyze computed tomographic (CT) findings of chronic idiopathic interstitial pneumonia (IIP) and to determine which findings are most helpful for distinguishing IIP from usual interstitial pneumonia (UIP) with univariate and multivariate analyses. MATERIALS AND METHODS: Institutional review board approval and informed consent were not required for this retrospective review of patient records and images. Two observers working independently and without knowledge of the diagnosis evaluated the extent and distribution of various thin-section CT findings (ground-glass opacity, consolidation, reticulation, and honeycombing) in 92 patients (51 men, 41 women; mean age, 56 years; age range, 29-81 years) with a histologic diagnosis of UIP (n = 20), cellular nonspecific interstitial pneumonia (NSIP) (n = 16), fibrotic NSIP (n = 16), respiratory bronchiolitis-associated interstitial lung disease (RB-ILD) (n = 11), desquamative interstitial pneumonia (DIP) (n = 15), or lymphoid interstitial pneumonia (LIP) (n = 14). Observers used univariate and multivariate statistical analyses to compare their findings with the extent and distribution of UIP. RESULTS: Observers made the correct diagnosis in 145 (79%) of 184 readings. Multivariate logistic regression analysis showed that the independent findings that distinguished UIP from cellular NSIP were the extent of honeycombing and the most proximal bronchus with traction bronchiectasis (odds ratio, 5.16 and 0.37, respectively); the finding that distinguished UIP from fibrotic NSIP was the extent of honeycombing (odds ratio, 2.10). CT features that distinguished UIP from RB-ILD and DIP included extent of ground-glass opacity (odds ratio, 0.76), thickening of bronchovascular bundles (odds ratio, 1.58), the most proximal bronchus with traction bronchiectasis (odds ratio, 0.22), and the number of segments with traction bronchiectasis (odds ratio, 3.64). CONCLUSION: UIP has a characteristic appearance that usually facilitates distinction from other types of chronic IIPs at thin-section CT. The most useful finding when differentiating UIP from NSIP was the extent of honeycombing.

Adult↗

PubMed2006

CT-guided needle biopsy of lung lesions: a survey of severe complication based on 9783 biopsies in Japan.

PURPOSE: The aim of our study was to update the rate of severe complications following CT-guided needle biopsy in Japan via a mailed survey. MATERIALS AND METHODS: Postal questionnaires regarding CT-guided needle biopsy were sent out to multiple hospitals in Japan. The questions regarded: the total number and duration of CT-guided lung biopsies performed at each hospital, and the complication rates and numbers of pneumothorax, hemothorax, air embolism, tumor seeding, tension pneumothorax and other rare complications. Each severe complication was followed with additional questions. RESULTS: Data from 9783 biopsies was collected from 124 centers. Pneumothorax was the most common complication, and occurred in 2412 (35%) of 6881 cases. A total of 39 (35%) hospitals reported 74 (0.75%) cases with severe complications. There were six cases (0.061%) with air embolism, six cases (0.061%) with tumor seeding at the site of the biopsy route, 10 cases (0.10%) with tension pneumothorax, six cases (0.061%) with severe pulmonary hemorrhage or hemoptysis, nine cases (0.092%) with hemothorax, and 27 cases (0.26%) with others, including heart arrest, shock, and respiratory arrest. From a total of 62 patients with severe complications, 54 patients (0.55%) recovered without sequela, however one patient (0.01%) recovered with hemiplegia due to cerebral infarction, and the remaining seven patients (0.07%) died. CONCLUSIONS: This is the first national study documenting severe complications with respect to CT-guided needle biopsy in Japan. The complication rate in Japan is comparable to internationally published figures. We believe this data will improve both clinicians as well as patients understanding of the risk versus benefit of CT-guided needle biopsy, resulting better decisions.

Biopsy, Needle↗

PubMed2006

Evaluation of coronary artery bypass grafts using multidetector-row CT with Japanese patients.

PURPOSE: To evaluate the patency of coronary artery bypass grafting (CABG) with multidetector-row computed tomography (MDCT) in Japanese patients, who have narrower coronary arteries than Caucasians. MATERIALS AND METHODS: Nineteen patients (12 men and 7 women, mean age: 63 +/- 12 years) with 33 coronary bypass grafts were examined with three-dimensional volume rendering (3D-VR) and curved multiplanar reconstruction (MPR) of MDCT. All grafts were compared with those obtained with selective graft angiography. RESULTS: For the 19 patients with 33 grafts, the overall sensitivity and specificity, compared with those for selective bypass angiography, were 96.7% and 100%, respectively. CONCLUSION: The patency of CABG in Japanese patients can be effectively evaluated with 3D-VR and curved MPR of MDCT.

Angiography↗

PubMed2006

Evaluation of the usefulness of color digital summation radiography in temporally sequential digital radiographs: a phantom study.

PURPOSE: The purpose of this study was to assess the usefulness of color digital summation radiography (CDSR) for detection of nodules on chest radiographs by observers with different levels of experience. MATERIALS AND METHODS: A total of 30 radiographs of chest phantoms with abnormalities and 30 normal ones were arranged at random. Set A was conventional radiographs only. Set B consisted of both conventional radiographs and CDSR images, which were colored with magenta. Five chest radiologists and five residents evaluated both image sets on a TFT monitor. The observers were asked to rate each image set using a continuous rating scale. The reading time for each set was also recorded. RESULTS: In set A, the performance of chest radiologists was significantly superior to that of the residents (P < 0.05). However, in set B, there was no significant difference in the performance of the chest radiologists and the residents. In both observer groups, the mean reading time per case in set B was significantly shorter than that in set A (P < 0.01). CONCLUSION: By using CDSR, the detection capability of observers with little experience improves and is comparable to that of experienced observers. Moreover, the reading time becomes much shorter using CDSR.

Color↗

PubMed2006

MR imaging of thymic epithelial tumors: correlation with World Health Organization classification.

PURPOSE: The aim of this study was to determine magnetic resonance imaging (MRI) features of various subtypes of thymic epithelial tumors based on the World Health Organization classification. MATERIALS AND METHODS: The study included 64 patients with histologically proven thymic epithelial tumors. Two observers evaluated the MRI findings in terms of tumor size, contour, lobulation, shape, homogeneity, the presence of intratumor high- and low-signal foci, enhancement degree and pattern, the presence of capsule and septum, and associated mediastinal lymphadenopathy and pleural effusion. RESULTS: Type A tumors were more likely to have a smooth contour, round shape, distinct capsule, and smaller size compared to any other type of thymic epithelial tumor. Thymic carcinomas demonstrated a higher prevalence of low-signal foci within the mass on T2-weighted images and mediastinal lymphadenopathy than any other types. The frequency of heterogeneous intensity on T2-weighted images increased from type A tumors to thymic carcinomas. CONCLUSION: The presence of a smooth contour, round shape, and capsule is highly suggestive of a type A tumor. Foci of low signal intensity in the mass on T2-weighted images and mediastinal lymphadenopathy are highly suggestive of thymic carcinomas.

Adult↗

PubMed2006

Evaluation of usefulness of color digital summation radiography for solitary pulmonary nodules on chest radiographs.

PURPOSE: The aim of this study was to evaluate the usefulness of novel color digital summation radiography (CDSR) for detecting solitary pulmonary nodules on chest radiographs by observers with different levels of experience. MATERIALS AND METHODS: A total of 30 healthy controls and 30 patients with newly detected solitary pulmonary nodules were evaluated. Six radiologists and five residents evaluated three image sets: set A, current and prior radiographs only; set B, set A with temporal subtraction images; and set C, set A with CDSR. The observers were asked to rate each image set using a continuous rating scale. In addition, the reading time required for each set was recorded. RESULTS: The radiologists showed no significant differences in the mean A(z) value between set A, set B, and set C. However, the residents showed significant differences between set A and set B and between set A and set C. In addition, for set B and set C, the mean reading time per case of all readers was significantly shorter than that for set A. CONCLUSION: The detection capability of observers with little experience is comparable to that of experienced observers when reading radiographs with temporal subtraction images or with CDSR. The usefulness of CDSR is comparable to that of temporal subtraction.

Clinical Competence↗

PubMed2005

Two cases of primary pulmonary osteosarcoma.

Two cases of primary pulmonary osteosarcoma are presented. In both cases, chest computed tomography revealed a calcified pulmonary mass and technetium-99m methylene diphosphonate bone scintigraphy showed intense uptake in the pulmonary mass. Primary pulmonary osteosarcoma was suspected on the basis of these radiographic findings. Microscopic examination of tumor specimens obtained by needle biopsy revealed histologic features of osteosarcoma, and this diagnosis was confirmed by postmortem examination of a second specimen in each case. Radiographic and histopathological findings enabled us to diagnose primary pulmonary osteosarcoma, which is one of the rarest types of cancer.

Aged↗

PubMed2005

Full-size digital storage phosphor chest radiography: effect of 4K versus 2K matrix size on observer performance in detection of subtle interstitial abnormalities.

PURPOSE: To compare observer performance in the detection of subtle interstitial abnormalities on 3,520 x 3,520 (4K) matrix and 1,760 x 1,760 (2K) matrix full-size digital storage phosphor (DSP) chest radiographs. MATERIALS AND METHODS: Thirty-five 4K DSP chest radiographs with subtle interstitial abnormalities (n=27) or normal lungs (n=8) were processed with a half-band low-pass filter to produce 2K DSP radiographs. Although the actual matrix size of the 2K DSP radiographs remained 4K, the effective matrix size was reduced to 2K. Four chest radiologists independently evaluated full-sized hard-copy of the 4K and 2K DSP radiographs, and scored the presence of interstitial abnormalities for both right and left lungs on a five-point confidence scale. With findings on high-resolution computed tomography as the reference standard, observer performance was evaluated using multireader-multicase receiver operating characteristic (ROC) analysis. RESULTS: The average area under the ROC curve (Az) values for 4K and 2K DSP radiographs were 0.791+/-0.055 and 0.804+/-0.050, respectively. Both individual and averaged Az values showed no statistically significant differences (p>0.05) between 4K and 2K DSP radiographs. CONCLUSION: Observer performance in the detection of subtle interstitial abnormalities on 4K full-size DSP chest radiographs was equivalent to that on 2K full-size DSP chest radiographs.

Humans↗

PubMed2005

Aortic compliance in patients with aortic regurgitation: evaluation with magnetic resonance imaging.

PURPOSE: To assess by means of cine magnetic resonance imaging (MRI) aortic compliance before and after aortic valve replacement (AVR with SJM valve) in patients with aortic regurgitation (AR). MATERIALS AND METHODS: Two groups (healthy controls and patients with severe isolated AR) of 10 subjects each were included in this study. Cine MRI was performed at three locations of the aorta, and aortic compliance was calculated by dividing the maximum change in the aortic area by pulse pressure. RESULTS: Cine MRI is useful to assess abnormalities of aortic compliance in patients with AR. Compared with the control group, aortic compliance in the AR group was significantly less in the ascending aorta (p<0.05), decreasing in order of aortic location. After AVR, aortic compliance improved for all locations. CONCLUSION: Cine MRI enables assessment of aortic biophysical properties such as a compliance for evaluating the progression of AR and the efficacy of treatment.

Adult↗

PubMed2005

Voxel dimensions required for micromorphologic evaluation of ground-glass opacity on lung high-resolution CT.

PURPOSE: To clarify the appropriate voxel dimensions required for pathologic evaluation of areas with ground-glass opacity on lung high-resolution computed tomography (HRCT). MATERIALS AND METHODS: Synchrotron radiation CT (SRCT) images of autopsied lung speci-mens (n=25) that showed ground-glass opacity on HRCT were reconstructed with 12 different voxel dimensions ranging from 0.006 to 0.6 mm. The specimens were micromorphologically categorized into one of three pathologic groups: alveolar, interstitial, and mixed abnormalities. Each SRCT image was independently diagnosed as one of three pathologic groups by six chest radiologists. The diagnostic accuracy required to estimate the appropriate voxel dimensions was compared among different voxel dimensions by means of the Tukey test. RESULTS: Diagnostic accuracy with voxel dimensions less than or equal to 0.06 mm was significantly higher than that with voxel dimensions of 0.18 mm or more (p<0.01). There was, however, no significance of difference in diagnostic accuracy with voxel dimensions of less than or equal to 0.06 mm. In addition, no significant difference in diagnostic accuracy was found with voxel dimensions of 0.18 mm or more. CONCLUSION: The appropriate voxel dimensions are approximately 0.06 mm for pathologic differentiation of areas with ground-glass opacity on HRCT.

Humans↗

PubMed2005

Image quality of high-resolution CT with 16-channel multidetector-row CT: comparison between helical scan and conventional step-shoot scan.

OBJECTIVE: The aim of this study was to evaluate the image quality of high-resolution CT (HRCT) reconstructed from volumetric data with 16-channel multidetector-row CT (MDCT). SUBJECTS AND METHODS: Eleven autopsy lungs that were diagnosed histopathologically were scanned by 16-channel MDCT with the step-and-shoot scan mode and three helical scan modes. Each helical mode had each size of focal spot, pitch, and time of gantry rotation. HRCT images were reconstructed from the volumetric data with each helical mode and axial sequence data. Two observers evaluated the image quality and noted the most appropriate diagnosis for each imaging. RESULTS: Visualization of abnormal structures with one helical mode was equal to those with axial mode, whereas those with the other two helical modes were inferior to those with axial mode (Wilcoxon signed rank test; p<0.0001). There was no significant difference in diagnostic efficacy between modes. CONCLUSION: The image quality of HRCT with appropriate helical mode is equal to that with axial mode and diagnostic efficacy is equal among all modes. These results may indicate that sufficient HRCT images can be obtained by only one helical scan without the addition of conventional axial scans.

Cadaver↗

PubMed2004

[PACS for multi-slice CT--seamless integration implementing 3D and 4D workstations].

A PACS system for data management in multi-slice CT examination was upgraded using interactive 3D and 4D workstations and network computing technology. We categorized the original PACS (CT-PACS) as follows: (1) a fault-tolerant system linked with the hospital information system (HIS) and radiology information system (RIS); (2) an interactive network system using a workstation with real-time 3D and 4D reconstruction; (3) a system for research and development of software for 3D image analysis on the CT-PACS system. Because of the use of cooperative diagnostic supporting tools, no major problems occurred in daily clinical practice or research and education. In conclusion, CT-PACS with real-time 3D and 4D workstations was found to be helpful to radiologists and researchers in reading and analyzing large volumetric data.

Computer Communication Networks↗

PubMed2003

Detection of pulmonary metastases with multi-detector row CT scans of 5-mm nominal section thickness: autopsy lung study.

PURPOSE: To determine the effect of changing pitch and collimation on depiction of pulmonary metastases on scans of 5-mm section thickness obtained with multi-detector row computed tomography (CT) compared with those obtained with single-detector row CT. MATERIALS AND METHODS: In five autopsy lungs, 1,013 metastatic 0.5-30.0-mm nodules were detected at helical CT with 1-mm collimation and histopathologically diagnosed as metastases. Each nodule was numbered, and its localization was recorded as the standard for subsequent studies. Four types of scans of 5-mm section thickness were obtained with multi-detector row CT and four sets of helical pitch and table speed, respectively, as follows: set A, 3:1 and 7.5 mm per rotation; set B, 6:1 and 15 mm per rotation; set C, 6:1 and 30 mm per rotation; set D, conventional and 5-mm interval. Conventional helical CT scans (set E) were obtained with 5-mm collimation at single-detector row CT. Two independent observers evaluated the five sets of CT scans. RESULTS: Acquisition times for sets A-D, respectively, were 1.9, 3.8, 7.5, and 1.5 times faster than they were for set E. The mean numbers of detected nodules were 671 (66%) in set A, 661 (65%) in set B, 678 (67%) in set C, 654 (65%) in set D, and 656 (65%) in set E; there was no significant difference in the number of detected nodules among the five sets (P =.997, McNemar test and Bonferroni equation). CONCLUSION: Regardless of varying pitch or detector collimation, multi- and single-detector row CT scans obtained with 5-mm section thickness have almost the same ability to depict pulmonary metastases and are equivalent.

Autopsy↗

PubMed2003

Chronic cystic lung disease: diagnostic accuracy of high-resolution CT in 92 patients.

OBJECTIVE: The objective of this study was to determine whether the various chronic cystic lung diseases can be differentiated on the basis of the pattern and distribution of abnormalities on high-resolution CT. MATERIALS AND METHODS: High-resolution CT scans in 92 patients with chronic cystic lung diseases (18 with pulmonary Langerhans cell histiocytosis, 18 with pulmonary lymphangioleiomyomatosis, 17 with usual interstitial pneumonia, 16 with lymphocytic interstitial pneumonia, 15 with emphysema, and eight with desquamative interstitial pneumonia or respiratory bronchiolitis interstitial lung disease) were retrospectively assessed by two independent observers without knowledge of the clinical or pathologic data. The observers recorded the abnormalities, the most likely diagnosis, and the degree of confidence in that diagnosis. RESULTS: The two observers made a correct first-choice diagnosis in 148 (80%) of 184 interpretations. The correct diagnosis was made in 100% of interpretations of usual interstitial pneumonia, 81% of desquamative interstitial pneumonia or respiratory bronchiolitis interstitial lung disease, 81% of lymphocytic interstitial pneumonia, 77% of emphysema, 72% of lymphangioleiomyomatosis, and 72% of Langerhans cell histiocytosis. The two observers made a diagnosis with a high degree of confidence in 105 (57%) of 184 interpretations. The confident diagnosis was correct in 98 (93%) of 105 interpretations. CONCLUSION: Although various chronic cystic lung diseases often have a characteristic appearance that allows their distinction on high-resolution CT, considerable overlap exists among the CT findings. Therefore, lung biopsy is often required for a definitive diagnosis.

Adolescent↗

PubMed2002

Temporal subtraction for detection of solitary pulmonary nodules on chest radiographs: evaluation of a commercially available computer-aided diagnosis system.

PURPOSE: To evaluate the usefulness of a commercially available computer-aided diagnosis (CAD) system that incorporates temporal subtraction for the detection of solitary pulmonary nodules on chest radiographs by readers with different levels of experience. MATERIALS AND METHODS: Sixty pairs of chest radiographs in 30 patients with newly detected solitary pulmonary nodules and 30 normal cases, all confirmed with serial chest computed tomography (CT), were obtained from screen-film or digital radiographic systems and were digitized (spatial resolution, 0.171 mm/pixel). Temporal subtraction images were produced with an iterative image-warping technique. Five chest radiologists and five residents evaluated both image sets for solitary nodules: set A, current and prior radiographs with temporal subtraction images, and set B, current and prior radiographs only. Assessment was performed with receiver operating characteristic (ROC) analysis of the images on a monitor (pixel size, 1,280 x 1,024) equipped with the system. The reading time needed by each reader was recorded in each case. RESULTS: For the chest radiologists, no statistically significant difference was found between set A (area under the ROC curve [A(z)] = 0.934) and set B (A(z) = 0.964). For the residents, however, observer performance in set A (A(z) = 0.907) was superior to that in set B (A(z) = 0.855) (P <.05). For both groups, the mean reading time per case for set A (chest radiologists, 16.7 seconds; residents, 15.7 seconds) was significantly (P <.05) shorter than that for set B (chest radiologists, 20.4 seconds; residents, 26.2 seconds). CONCLUSION: For the detection of solitary pulmonary nodules, the CAD system with temporal subtraction can promote efficiency for established chest radiologists and improvement in accuracy for less experienced readers.

Adult↗

PubMed2002

Detection of lung cancer on chest radiographs: analysis on the basis of size and extent of ground-glass opacity at thin-section CT.

PURPOSE: To evaluate the detection of small peripheral lung tumors on chest radiographs on the basis of the size of the tumor and its extent of ground-glass opacity (GGO) at thin-section computed tomography (CT). MATERIALS AND METHODS: Chest radiographs of 75 patients with peripheral carcinomas 20 mm in diameter or smaller (26 localized bronchioloalveolar carcinomas [BACs], 49 other carcinomas) and 60 normal chest radiographs were retrospectively reviewed individually by 10 radiologists. The extent of GGO within the lesions at thin-section CT was reviewed retrospectively. The detection rates for localized BAC and other carcinomas on chest radiographs were calculated and were correlated with tumor size and extent of GGO. RESULTS: The mean sensitivity for detection of small peripheral carcinomas was 58.5% +/- 8.8 (standard error) for localized BAC and was 78.6% +/- 5.1 for other carcinomas (P =.024). Lesions that were smaller than 15 mm in diameter and had an extent of GGO of 70% or greater at thin-section CT were more difficult to detect than tumors that had larger diameters or less extensive GGO (chi(2) = 8.13, df = 1, P =.004). CONCLUSION: The detection of small peripheral carcinomas on chest radiographs is influenced by tumor size and extent of GGO as seen at thin-section CT.

Adenocarcinoma, Bronchiolo-Alveolar↗