Biomedical subjects

Shuji Yamamoto

Publications and source records attributed to Shuji Yamamoto.

42 records · Page 3Linked to original sources

PubMedDate not supplied

Unusual neutrophil infiltration under the soft contact lens in a patient with Behçet's disease.

BACKGROUND: Behçet's disease (BD) characterized by multisystemic disorders has many kinds of ocular involvement. We report one case of BD with unusual neutrophil infiltration under a soft contact lens (SCL). CASE: A 31-year-old woman diagnosed as having BD exhibited bilateral recurrent phlyctenular keratitis and finally developed corneal perforation in the cornea of her right eye. OBSERVATIONS: A therapeutic SCL was immediately fitted on the right cornea as a bandage and another SCL on the left, as prophylaxis. White gelatinous membrane suddenly appeared between the bandage SCL and the cornea in the left eye. After peeling off this gelatinous membrane from the cornea, we examined it after hematoxylin-eosin staining. We also measured the levels of interleukin-8 (IL-8) both in the tears of the patient and on the surface of the SCL. A great amount of neutrophils had infiltrated into this gelatinous membrane. Laboratory data showed a marked increase of IL-8 levels both on the SCL and in the reflex tears (right SCL, 4980 pg/mL; left SCL, 6810 pg/mL. Reflex tears: right, 2080 pg/mL; left, 2170 pg/mL). CONCLUSION: This case emphasizes the association between the IL-8 level and the disease activity in BD, and provides additional evidence that a BD attack can be induced on the ocular surface under certain conditions.

Adult↗

PubMedDate not supplied

Quantitative analysis for computed tomography findings of various diffuse lung diseases using volume histogram analysis.

OBJECTIVES: : The aim of this study was to achieve the quantitative analysis of the characteristic computed tomography (CT) findings and course of interstitial pneumonia using the volume histogram method. METHODS: : Contrast (CNT), variance (VAR), and entropy (EPY) values from whole-lung volume data were compared between normal lungs and 5 diseases that have characteristic CT findings. Thirteen cases with nonspecific interstitial pneumonia (NSIP) were evaluated before and after treatment. RESULTS: : In cases with thickening of the bronchovascular bundles and interlobular thickening, ground-glass attenuation, airspace consolidation, and honeycombing, the values of VAR and EPY were greater than those in the normal cases (P < 0.05). In the cases with NSIP, the CNT value after treatment was significantly greater and the values of VAR and EPY after treatment were significantly lower than those before treatment (P < 0.05). CONCLUSIONS: : Volume histogram analysis is a promising method for the evaluation of diffuse lung diseases and the effectiveness of treatment.

Adolescent↗

PubMedDate not supplied

Coronal multiplanar reconstruction view from isotropic voxel data sets obtained with multidetector-row CT: assessment of detection and size of mediastinal and hilar lymph nodes.

OBJECTIVE: To assess the detection and size of mediastinal and hilar lymph nodes by multiplanar reconstruction (MPR) view from isotropic voxel data sets obtained with multidetector-row computed tomography (MDCT). MATERIALS AND METHODS: Thin-section CT of 27 patients with mediastinal or hilar lymph node swelling was obtained with a 25.6-cm FOV, 512 x 512 matrix, and two protocols: A) 0.5-mm collimation, 0.3-mm interval, and B) 2-mm collimation, 1-mm interval. MPR views with a 0.5-mm slice thickness were obtained from these two data sets. Postcontrast axial CT used 5-mm collimation (set C). Two observers evaluated the presence and cranio-caudal length of swollen lymph nodes. Two other board-certified chest radiologists evaluated all three sets and established a gold standard by consensus. RESULTS: The accuracy of detection was 76%, 73%, and 68% for sets A, B, and C, respectively. There was a significant difference between sets A and C (McNemar's test: p<0.05) but not between sets A and B or B and C (p>0.05). The cranio-caudal length of lymph nodes was significantly correlated with the gold standard only in set A (Pearson's correlation coefficient: r=0.53, p<0.05). CONCLUSION: Non-contrast enhanced coronal MPR views constructed from isotropic voxel data sets may be substituted for axial enhanced CT for the evaluation of mediastinal and hilar lymph nodes.

Adolescent↗

PubMedDate not supplied

Coronal multiplanar reconstruction view from whole lung thin-section CT by multidetector-row CT: determination of malignant or benign lesions and differential diagnosis in 68 cases of solitary pulmonary nodule.

PURPOSE: The purpose of this study was to evaluate the usefulness of the coronal multiplanar reconstruction (MPR) view in comparison with transverse helical thin-section CT for both the determination of malignant or benign lesions and the differential diagnosis of solitary pulmonary nodules. MATERIALS AND METHODS: Sixty-eight cases of pathologically proved solitary pulmonary nodule less than 3 cm in diameter were enrolled in this study. For the routine study, transverse helical thin-section CT (1.25 mm collimation, FOV 20 cm) covering the areas with solitary pulmonary nodules as well as whole lung helical thin-section CT (2.5 mm collimation, 1.25 mm reconstruction interval, FOV 34.5 cm, pitch 6:1, high-spatial frequency algorithm) were scanned with a multidetector-row CT (MDCT) scanner. From the whole lung thin-section CT data, coronal MPR views (2.5 mm slice thickness) were reconstructed on a workstation. ROC analysis was used for an observer performance study, in which three observers indicated their confidence level for the determination of malignant or benign lesion for the nodules by means of transverse thin-section CT and coronal MPR. In addition, the observers recorded appropriate disease entities as the final diagnosis of each case. Accuracies of the final diagnosis based on the two sets of images were compared with McNemer' s test. RESULTS: In terms of the determination of malignant or benign lesion, there was no significant difference between the two sets of images (coronal MPR and transverse thin-section CT; mean Az=0.853 and 0.854, respectively). In addition, accuracy of the final diagnosis based on coronal MPR views (74%) was almost equal to that based on transverse thin-section CT (71%) (p=0.3). CONCLUSIONS: The diagnostic efficacy of the coronal MPR view is comparable to that of transverse thin-section CT for the evaluation of solitary pulmonary nodules.

Adult↗

PubMedDate not supplied

Real-time estimation system for mean glandular dose in mammography.

PURPOSE: The purpose of this study was to construct a system that calculates mean glandular dose (MGD) in mammography in real-time on the RIS network. MATERIALS AND METHODS: Measurement of the half-value layer (HVL) and exposure dose were measured according to the Japanese mammographic quality control manual. A parallel plate chamber (10X5-6M; soft X-rays only) was used for measurement. Exposure dose was measured from 26 to 32 kV. RESULTS: Effective energy (Eeff [keV]) could be determined from tube voltage (V [kV] ) using the measure of the HVL according to the following equations: for the Mo/Mo combination, Eeff = 0.1325V + 11.80; for the Mo/Rh combination, Eeff = 0.1435V + 12.20; for the Rh/Rh combination, Eeff = 0.1724V + 11.29. Exposure output (XmAs [mR/mAs]), which can be determined from dosimetry per 1 mAs, becomes the following equation if effective energy is expressed as a variable: for the Mo/Mo combination, XmAs = 2.1329 Eeff2 - 57.784 Eeff + 392.71; for the Mo/Rh combination, XmAs = 1.1919 Eeff2 - 31.924 Eeff + 212.23; and for the Rh/Rh combination, XmAs = 2.6929 Eeff2 - 82.831 Eeff + 643.54. The MGD conversion factor (DgN [mGy/mR]) can be determined from effective energy using the ACR protocol according to the following equation: for the Mo/Mo combination, DgN = (0.3962 Eeff- 4.3178) 10(-3); for the Mo/Rh combination, DgN = (0.3495 Eeff - 3.5479) x 10(-3); and for the Rh/Rh combination, DgN = (0.4498 Eeff - 5.0448) x 10(-3). However, in these cases, compression breast thickness (CBT) was 4.2 cm, and the ratio of adipose and glandular tissue was 50/50. CONCLUSION: MGD can be determined using mAs obtained from mammography, exposure output (XmAs), MGD conversion factor (DgN), and source-skin distance compensation factor (SSDcf) according to the following equation: MGD [mGy] = mAs x XmAs [mR/mAs] x DgN [mGy/mR] x SSDcf where SSDcf = (64/(64 - CBT [cm]))2.

Breast↗

PubMedDate not supplied

Evaluation of major aortopulmonary collateral arteries (MAPCAs) using three-dimensional CT angiography: two case reports.

Pulmonary atresia (PA) and ventricular septal defect (VSD) are usually associated with major aortopulmonary collateral arteries (MAPCAs). Preoperative evaluation of MAPCAs is essential for effective planning of unifocalization. Multidetector-row computed tomography (MDCT) with three-dimensional volume rendering (3D-VR) demonstrates MAPCAs as well as conventional angiography. We report two cases of PA and VSD associated with MAPCAs examined pre- and postoperatively by means of angiography and MDCT with the 3D-VR technique. MDCT with the 3D-VR technique had the potential to elucidate all MAPCAs demonstrated by invasive angiography. This technique is useful with preoperative conventional angiography as a standard examination for the planning of staged surgery.

Adult↗