18F-Fluorodeoxyglucose positron emission tomography for evaluation of intravascular large B-cell lymphoma.
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Aged↗
Biomedical subjects
Takatoshi Aoki
Publications and source records attributed to Takatoshi Aoki.
Correlation between numeric gadolinium-enhanced dynamic MRI ratios and prognostic factors and histologic type of breast carcinoma.
OBJECTIVE: The purpose of this study was to assess the usefulness of numeric ratios from dynamic contrast-enhanced MRI in predicting histologic type of breast carcinoma and three histologic prognostic factors for invasive ductal carcinoma. MATERIALS AND METHODS: A total of 104 patients with breast carcinoma were included in the study. Dynamic contrast-enhanced MR images were obtained every 30 seconds during the first 4.5 minutes after administration of contrast material, and peripheral contrast enhancement ratio and central contrast enhancement ratio were calculated in the early phase (1 minute after contract injection) and in the delayed phase (4 minutes after injection). Four contrast enhancement ratios were used for quantitative analysis of the following numeric ratios: early peripheral/early central, delayed peripheral/delayed central, delayed peripheral/early peripheral, and delayed central/early central. The four ratios were compared with histologic type. For invasive ductal carcinoma, the ratios were then compared with modified Scarff-Bloom-Richardson histologic grade, microvessel density, and fibrotic focus. RESULTS: Mucinous carcinoma had significantly higher mean early peripheral/early central and delayed central/early central ratios than other types of tumors (p< 0.0001). For invasive ductal carcinoma, the mean early peripheral/early central ratio was significantly lower for modified Scarff-Bloom-Richardson grade 1 tumors than for grades 2 and 3 tumors (p < 0.0001). Early peripheral/early central ratio had a significant correlation with the ratio of peripheral to central mean microvessel density (p < 0.0001). There was also a significant difference in early peripheral/early central ratio (p < 0.0001) between tumors with a fibrotic focus and those without a fibrotic focus. CONCLUSION: Numeric ratios obtained on gadolinium-enhanced dynamic MRI of the breast may be useful in predicting histologic type of breast carcinoma and three histologic prognostic factors for invasive ductal carcinoma: modified Scarff-Bloom-Richardson grade, microvessel density, and fibrotic focus.
Adult↗
Effect of temporal subtraction technique on interpretation time and diagnostic accuracy of chest radiography.
OBJECTIVE: Our purpose was to compare reviewing time and diagnostic accuracy in the interpretation of radiographs without and with subtraction images and to examine whether this temporal subtraction technique can contribute to improving radiologists' performance. MATERIALS AND METHODS: Thirty cases with newly developed chest abnormalities on chest radiographs and 90 negative cases were selected. All chest radiographs were obtained with a computed radiography system. For the 90 negative cases, subtraction images were classified into two groups: 33 clean images without misregistration artifacts and 57 images with some misregistration artifacts. Eight radiologists (four board-certified radiologists and four radiology residents) participated in observer tests and interpreted the original radiographs without and with subtraction images using an independent test method. The reviewing time for each radiologist was recorded in each case. The observers' performance was evaluated by use of receiver operating characteristic (ROC) analysis. RESULTS: When subtraction images were available, the mean reviewing time per case was reduced significantly from 13.6 to 10.8 seconds for the cases with newly developed abnormalities (p < 0.001) and from 29.8 to 14.1 seconds for negative cases (p < 0.001). The reduction in the mean reviewing time with subtraction images was greater for clean images than for images with artifacts (17.7 vs 14.5 seconds, p < 0.001). The average mean area under the ROC curve value increased significantly from 0.942 without subtraction images to 0.988 with subtraction images (p = 0.025). There were significant differences in the sensitivity (0.963 with and 0.888 without the subtraction images) and the specificity (0.976 with and 0.899 without the subtraction images) (p < 0.001). CONCLUSION: The temporal subtraction technique can reduce reviewing time and also improve diagnostic accuracy in the interpretation of chest radiographs.
Etidronic Acid↗
Spinal epithelioid hemangioendothelioma with epithelioid angiosarcomatous areas.
Epithelioid hemangioendothelioma is a distinctive vascular tumor rarely involving bones. We report a case of epithelioid hemangioendothelioma in the cervical spine with angiosarcomatous areas. A 50-year-old female presented with dizziness while walking. A mixed sclerotic and osteolytic or destructive lesion was radiographically disclosed in her upper cervical vertebrae. Histologically, a laminectomy specimen exhibited areas of ordinary epithelioid hemangioendothelioma together with foci of more atypical epithelioid cell proliferation, closely resembling epithelioid angiosarcoma. This phenomenon has been exceptionally described in cases with skeletal lesions, which are typically of low-grade malignancy.
Biopsy↗
Congenital (infantile) pseudarthrosis of the fibula associated with osteofibrous dysplasia.
We describe a recently noted association of congenital (infantile) pseudarthrosis of the lower leg with osteofibrous dysplasia. The patient was a 2-year-old boy who presented with a deformed left ankle joint and three cutaneous cafe-au-lait spots. Radiography demonstrated pseudarthrosis of the left distal fibula and a round lucent lesion adjacent to the proximal part of the pseudarthrosis. Histologically, the surgically removed fibula with pseudarthrosis showed a fibromatosis-like fibrovascular proliferation and nonspecific reparative changes. The focal lucent area demonstrated a fibro-osseous lesion, which was histologically identical to osteofibrous dysplasia. This case provides further evidence that osteofibrous dysplasia may be associated with congenital (infantile) pseudarthrosis of the lower leg.
Child, Preschool↗
Improved detection of lung nodules on chest radiographs using a commercial computer-aided diagnosis system.
OBJECTIVE: The aim of this study was to evaluate the usefulness of a new commercially available computer-aided diagnosis (CAD) system with an automated method of detecting nodules due to lung cancers on chest radiograph. MATERIALS AND METHODS: For patients with cancer, 45 cases with solitary lung nodules up to 25 mm in diameter (nodule size range, 8-25 mm in diameter; mean, 18 mm; median, 20 mm) were used. For healthy patients, 45 cases were selected on the basis of confirmation on chest CT. All chest radiographs were obtained with a computed radiography system. The CAD output images were produced with a newly developed CAD system, which consisted of an image server including CAD software called EpiSight/XR. Eight radiologists (four board-certified radiologists and four radiology residents) participated in observer performance studies and interpreted both the original radiographs and CAD output images using a sequential testing method. The observers' performance was evaluated with receiver operating characteristic analysis. RESULTS: The average area under the curve value increased significantly from 0.924 without to 0.986 with CAD output images. Individually, the use of CAD output images was more beneficial to radiology residents than to board-certified radiologists. CONCLUSION: This CAD system for digital chest radiographs can assist radiologists and has the potential to improve the detection of lung nodules due to lung cancer.
Adult↗
Postsurgical change in the tracheal bifurcation angle after upper lobectomy: radiographic evaluation.
RATIONALE AND OBJECTIVES: The purpose of this study was to evaluate postsurgical changes in the tracheal bifurcation angle on chest radiographs after upper lobectomy and to determine whether bronchial repositioning after upper lobectomy mimics that in upper lobe collapse. MATERIALS AND METHODS: The authors selected 81 patients who had undergone upper lobectomy with complete mediastinal and subcarinal lymph node dissection and in whom chest radiographs had been obtained before operation and at four postoperative intervals. The interbronchial angle and the subcarinal angle were measured on the preoperative and postoperative radiographs and compared statistically. RESULTS: The average interbronchial angle and subcarinal angle during any postoperative period were significantly smaller than those before lobectomy (P < .001). These average angles decreased gradually during the postoperative periods. CONCLUSION: The tracheal bifurcation angle was decreased on follow-up chest radiographs in most patients who underwent upper lobectomy with mediastinal lymph node dissection. This finding may be useful for establishing a history of this surgical procedure on the basis of chest radiographs.
Adult↗
Clinical feasibility of noncontrast-enhanced magnetic resonance lymphography of the thoracic duct.
STUDY OBJECTIVE: The dilatation of the thoracic duct was previously demonstrated in liver cirrhosis by lymphangiography, endoscopic ultrasound, and at autopsy. The evaluation of the morphologic change of the thoracic duct may be important in assessing the altered lymphodynamics in liver cirrhosis. The objectives of this study were to determine which combination of posture and breathing phase during noncontrast-enhanced magnetic resonance lymphography (MRL) provided the clearest images, and to evaluate the morphologic changes in the thoracic duct in healthy volunteers and patients with liver disease and malignancy. DESIGN: Prospective study. SETTING: Community general hospital. DESIGN AND SUBJECTS: Twenty-three healthy volunteers and 113 patients underwent the MRL examination using a three-dimensional, half-Fourier, fast spin echo sequence on a 1.5-T, whole-body magnetic resonance system. The appropriate posture and breathing phase of MRL to obtain the best visualization was first determined by trial on 14 healthy volunteers. Morphologic changes of the thoracic ducts were evaluated in 23 healthy volunteers including the 14 healthy volunteers for the first trial and 113 patients using this appropriate method. The width of the thoracic ducts in both patients and volunteers was measured. MEASUREMENTS AND RESULTS: MRL with respiratory gating in the supine position depicted the thoracic duct well and was the most comfortable for the subjects. In 82 of 113 patients (72.6%), the thoracic ducts were entirely visualized from the diaphragm level to the subclavian region. The remaining 31 patients had ducts that could not be entirely visualized due to sections or short lengths that were obscured. The maximum diameter was 3.74 +/- 0.81 mm in all healthy volunteers, 6.98 +/- 2.77 mm in alcoholic cirrhosis, 4.12 +/- 1.51 mm in nonalcoholic cirrhosis, 3.76 +/- 1.10 mm in malignancy, and 3.60 +/- 0.80 mm in chronic hepatitis (mean +/- SD). The diameter in alcoholic cirrhosis was significantly greater than in other groups (p < 0.01). CONCLUSIONS: Respiratory gating in the supine position is the best MRL method for acquiring the clearest images. This may be a good method of detecting morphologic changes in the thoracic duct. The patients with alcoholic cirrhosis showed a greater thoracic duct diameter than other groups.
Adult↗
Differential diagnosis of benign peripheral lipoma from well-differentiated liposarcoma on MR imaging: is comparison of margins and internal characteristics useful?
OBJECTIVE: Our objective was to evaluate the reliability of MR imaging in distinguishing between benign lipoma and well-differentiated liposarcoma. MATERIALS AND METHODS: The MR images of 35 pathologically proven benign lipomas in 35 patients and 23 well-differentiated liposarcomas in 17 patients were retrospectively reviewed. T1-, T2-, and fat-suppressed T1-weighted images were obtained after administration of gadopentetate dimeglumine. Margins and internal characteristics revealed on the MR images and the degree of contrast enhancement of septa were evaluated. These MR imaging findings were compared for well-differentiated liposarcomas and benign lipomas. RESULTS: Completely irregular margins were recognized only in benign lipomas with a pathologic diagnosis of infiltrating lipoma. All tumors without a recognizable nonadipose component were benign lipomas (p < 0.05). As for the well-differentiated liposarcomas, thick septa and nodular or patchy nonadipose components were present more frequently in deep and retroperitoneal lesions than in subcutaneous lesions (p < 0.01). No cases showed only thin septa in the deep lesions of well-differentiated liposarcoma, and all cases showed thick septa or nodular or patchy nonadipose components. The septa in well-differentiated liposarcomas enhanced more strongly than did those in benign lipomas. The septa showed no enhancement relative to muscle in 11 of 19 benign lipomas, whereas the septa showed moderate or marked enhancement in all well-differentiated liposarcomas (p < 0.01). CONCLUSION: Careful assessment of margins and internal characteristics on MR imaging can be a useful aid in further distinguishing between biologically different benign lipoma and well-differentiated liposarcoma.
Adult↗
[New evaluation for osteoporosis using calcaneal computed radiographs].
Quantitative analysis of bone mass is a method mainly used for the diagnosis of osteoporosis. However, there are cases of osteoporosis that cannot be diagnosed by this method alone. This study was performed to develop a new quantitative method for the evaluation of osteoporosis using texture analysis and geometric feature analysis of trabecular bone on lateral calcaneal computed radiographs. Thirty-seven cases including 11 normal and 26 abnormal lateral calcaneal radiographs were examined. The patients' ages ranged from 24 to 89 years (average age, 58.3 years). The root mean square (RMS) variation and first moment of power spectrum of trabecular bone patterns were determined as quantitative measures for texture analysis. In addition, the total area and total length of trabecular bone were obtained from geometric feature analysis. The RMS variations in pixel values, total area, and total length of trabecular bone were decreased as bone atrophy progressed. These three quantitative measures corresponded well to radiologists' subjective evaluations of bone atrophy. Moreover, our results indicated that these three quantitative measures had strong correlations with bone mineral density of the femoral neck. Therefore, we consider the computerized method with texture analysis and geometric feature analysis of lateral calcaneal radiographs to be very useful for radiologists in evaluating osteoporosis.
Adult↗
[Symposium III computer-aided diagnosis: benefits and challenges in diagnostic radiology. 6. Usefulness of temporal subtraction images of chest computed radiography].
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Adolescent↗
MRI findings including gadolinium-enhanced dynamic studies of malignant, mixed mesodermal tumors of the uterus: differentiation from endometrial carcinomas.
Our objective was to evaluate the usefulness of MRI including dynamic study in differentiating malignant, mixed mesodermal tumor (MMMT) from endometrial carcinoma (EC). The MR images were reviewed in 4 patients with histologically confirmed MMMT and 11 patients with EC. Flow voids inside and/or around the tumors were seen in 2 patients with MMMT but not in any EC cases. In dynamic studies, all 4 patients with MMMT showed areas of early and persistent marked enhancement similar to that of the myometrium, mixed with areas of gradual and delayed marked enhancement. The portions showing early and persistent enhancement histologically corresponded to predominantly sarcomatous components with prominent vascularity. Ten of 11 ECs did not show such enhancement and only one showed a rapid enhancement in the early phase which was diminished in the delayed phase. The MR imaging with a gadolinium-enhanced dynamic study seems to be useful in differentiating MMMT from EC.
Aged↗
Extraskeletal myxoid chondrosarcoma arising in the finger.
Extraskeletal myxoid chondrosarcoma (EMCS) is a rare soft tissue sarcoma and usually occurs in deep soft tissues, especially of the proximal extremities and limb girdles. We present an unusual case of the tumor arising in the finger. The diagnosis was confirmed by molecular detection of a characteristic EWS-CHN/TEC fusion gene transcript. Molecular detection of the tumor specific fusion gene could be a valuable aid for the final diagnosis of EMCS, particularly in cases with unusual clinicopathological features.
Artificial Gene Fusion↗
Usefulness of an artificial neural network for differentiating benign from malignant pulmonary nodules on high-resolution CT: evaluation with receiver operating characteristic analysis.
OBJECTIVE: The purpose of our study was to use an artificial neural network to differentiate benign from malignant pulmonary nodules on high-resolution CT findings and to evaluate the effect of artificial neural network output on the performance of radiologists using receiver operating characteristic analysis. MATERIALS AND METHODS: We selected 155 cases with pulmonary nodules less than 3 cm (99 malignant nodules and 56 benign nodules). An artificial neural network was used to distinguish benign from malignant nodules on the basis of seven clinical parameters and 16 radiologic findings that were extracted by attending radiologists using subjective rating scales. In the observer test, 12 radiologists (four attending radiologists, four radiology fellows, and four radiology residents) were presented with high-resolution CT images, first without and then with the artificial neural network output. Observer performance was evaluated by means of receiver operating characteristic analysis using a continuous rating scale. RESULTS: The artificial neural network showed a high performance in differentiating benign from malignant pulmonary nodules (A(z) = 0.951). The average A(z) value for all radiologists increased by a statistically significant level, from 0.831 to 0.959, with the use of the artificial neural network output. CONCLUSION: Our computerized scheme using the artificial neural network can improve the diagnostic accuracy of radiologists who are differentiating benign from malignant pulmonary nodules on high-resolution CT.
Adult↗