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Biomedical subjects

F Sakai

Publications and source records attributed to F Sakai.

276 records · Page 16Linked to original sources

Computed tomography of neck lymph nodes involved with malignant lymphoma: comparison with ultrasound.

CT images of 24 patients with head and neck lymphoma were retrospectively reviewed, compared with ultrasonograms, and compared with CT images of 13 patients with lymph node metastases. In nine (38%) of 24 patients, some lymph nodes with lymphomatous involvement showed a spotty or linear pattern of contrast enhancement. In two of these nine patients, a dendritic pattern of contrast enhancement between multiple enlarged lymph nodes was observed. The same pattern appeared as spotty, linear, or dendritic hyperechoic areas on the ultrasonogram. None of 13 patients with lymph node metastases showed a spotty, linear, or dendritic pattern of contrast enhancement. Ten of 13 (77%) showed ring-like contrast enhancement on CE-CT images. The spotty or linear contrast enhancement in enlarged lymph nodes and the dendritic contrast enhancement in confluent lymph nodes could be useful CT findings in diagnosing nodal involvement with malignant lymphoma.

Adult↗

Size of normal hilar lymph nodes measured in autopsy specimens.

The normal size of lymph nodes for each region of the hilum was determined by direct measurement of the short and long diameters of each node in the transverse plane of the node and the longitudinal diameter in the vertical plane of the node in 30 adult cadavers. The mean short transverse diameters ranged from 3.2 to 6.4 mm, the mean long transverse diameters ranged from 4.9 to 10.0 mm, and the mean longitudinal diameters ranged from 5.7 to 11.3 mm. The largest mean transverse diameters were found in the anterior upper lobe (AUL) and the inferior interlobar (IIL) regions. We noted a different maximum normal size for lymph nodes in each region of the hilum and determined the standard maximum normal short transverse diameters to be as follows: 12 mm for nodes in the right AUL and IIL regions, 10 mm for nodes in the right superior interlobar region and the left AUL and IIL regions, and 8 mm for nodes in other regions. Both the maximum normal long transverse diameters and the longitudinal diameters showed a wider variation, ranging from 18 to 10 mm and from 20 to 12 mm, respectively.

Adult↗

Iodine-enhanced CT patterns after cerebral arterial embolization in baboons.

The pathophysiology of iodine-enhanced computed tomography (CT) patterns produced by embolic arterial cerebral infarction in the baboon is reported. The appearance of iodine patterns in zones of nonperfusion, blood-brain barrier damage, loss of autoregulation, and neovascularity is demonstrated. The iodine CT patterns were correlated with stable xenon CT flow studies, regional cerebral blood flow studies, clinical course, and pathology.

Animals↗

MR evaluation of laryngohypopharyngeal cancer: value of gadopentetate dimeglumine enhancement.

PURPOSE: To investigate the value of gadopentetate dimeglumine-enhanced MR imaging in determining the extent of laryngohypopharyngeal cancer. METHODS: Unenhanced and contrast-enhanced T1-weighted, proton-density-weighted, and T2-weighted images from 24 patients with laryngohypopharyngeal cancer were reviewed and compared with the pathologic findings of resected specimens. In 18 patients, ex vivo MR images of the resected specimens were also compared with pathologic findings. RESULTS: Laryngohypopharyngeal cancer showed intermediate intensity on T1-weighted and proton-density-weighted images, high intensity on T2-weighted images, and moderate enhancement on T1-weighted enhanced images. Cartilage-invaded tumor enhanced moderately, whereas unossified cartilage in contact with tumors but without tumor invasion showed no enhancement. Laryngohypopharyngeal mucosa enhanced intensely; endolaryngeal muscles enhanced less. CONCLUSIONS: Enhanced MR images were more useful in assessing the extent of tumors and the presence of laryngeal cartilage invasion than were proton-density-weighted and T2-weighted images.

Aged↗

Digital tomosynthesis imaging of the lung.

We report our preliminary results of pulmonary imaging by digital tomosynthesis, and describe some advantages of these digitally processed longitudinal tomographic images. Digital tomosynthesis of the lung was performed in 60 subjects, including 56 patients with a localized lesion or diffuse disseminated lesions, with a fluororadiographic TV unit with linear tomographic capability, in conjunction with an image processing unit. Dual energy subtraction digital tomosynthesis was also available in our system. Multiple longitudinal tomographs of the lung, which were reconstructed from a single set of tomographic image data, facilitated easy evaluation of the morphology of pulmonary abnormalities together with related broncho-vascular structures located in the same longitudinal plane as the lesion, and were immune from any problem caused by inconsistent depth of respiration. The image quality of the reconstructed tomographs was greatly improved by digital image processing to reduce tomographic blur and enhance image clarity. Dual energy subtraction digital tomosynthesis was effective in clearly showing the size, configuration, and distribution of calcification in the lesion. Digital tomosynthesis provided useful information in making the roentgenologic diagnosis of pulmonary lesions.

Adult↗