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Biomedical subjects

N Yanagimachi

Publications and source records attributed to N Yanagimachi.

9 recordsLinked to original sources
PubMed2000

A dynamic analysis of chest wall motions with MRI in healthy young subjects.

OBJECTIVE: The objective of this study was to analyse respiratory-related motion of the chest wall with non-invasive method. METHODOLOGY: Using magnetic resonance image (MRI), 30 sequential images (scanning time, 0.4 s per image) on sagittal, axial and coronal planes were obtained in nine healthy young subjects during quiet breathing (QB) and maximal deep breathing (MDB). The coronal planes were obtained in five of nine subjects during MDB. Ventilation was simultaneously measured with pneumotachometer. RESULTS: There was a linear correlation between instantaneous lung volume and lung cross-sectional area. Motion of the diaphragm and rib cage was also linearly related to instantaneous lung volume. The exception was lower anteroposterior (AP) diameter of the rib cage. The contribution of individual part of the chest wall motion to a unit lung volume change was assessed by slope (S) of the linear regression line. The S at the anterior diaphragm was significantly smaller than those at middle and posterior parts during MDB. The S of middle and posterior diaphragmatic motion was approximately five times that of AP motion of upper rib cage. The S of AP motion of upper rib cage was twice that of transverse motion during either QB or MDB. CONCLUSION: We concluded that dynamic MRI study with concurrent ventilation measurement is a simple and reliable method for evaluation of local chest wall motion, and that neither diaphragm nor rib cage works as a single functional unit during active ventilation.

Adult↗
PubMed1998

Parasellar dermoid tumor with intra-tumoral hemorrhage.

We report a case of parasellar dermoid tumor with intra-tumoral hemorrhage. It is rare for a dermoid tumor that hemorrhage was detected as high attenuation on the initial CT. In the present case, the tumor content included a little fat component and mostly cholesterin-rich fluid which resulted in extremely low signal intensity on T2-weighted and high signal on T1-weighted MR images. In addition to this, hemosiderin accumulation in the tumor could be the reason for low signal intensity on T2-weighted images.

Adipose Tissue↗
PubMed1998

Fatal alveolar hemorrhage in a patient with mixed connective tissue disease presenting polymyositis features.

A 22-year-old female with Raynaud's phenomenon, swollen hands and a high titer of anti-RNP antibodies developed fever and myositis. Prednisolone (40 mg/day) was considered effective for myositis since circulating myogenic enzymes rapidly decreased. However, she suddenly developed respiratory distress with bilateral pulmonary infiltrates and bloody sputum. Under the diagnosis of alveolar hemorrhage (AH), intravenous methylprednisolone pulse therapy was given, but she died of respiratory failure. Autopsy findings demonstrated massive AH with hematoma formation, and myositis in the iliopsoas muscle. Depositions of immune complex and vasculitic lesions were not recognized in her lungs.

Adult↗
PubMed1997

Analysis of intramedullary cell density by MRI using the multiple spin-echo technique.

Analysis of the intramedullary cell distribution by magnetic resonance imaging (MRI) using conventional techniques involves subjectively interpreting images and estimating the cell distribution on the basis of signal intensity characteristics. In recent years, attempts have been made to achieve more precise analysis by new techniques, including chemical shift imaging. The multiple spin-echo (MSE) technique offers some advantages over conventional MRI. Since it allows measurement of the transverse magnetization decay curve at 32 or more points, it is capable of separating several tissue components with different relaxation times. In addition, this technique can be used with MRI instruments having a static magnetic field as low as 1.0 Tesla. In the present study, the intramedullary cell density was assessed by MRI using the MSE technique in 4 patients with aplastic anemia (AA), 4 patients with myelodysplastic syndrome (MDS), and 5 normal subjects. The water component of the marrow (with a short relaxation time) and the fat component (with a long relaxation time) were separated from each other by analyzing MR images obtained using the MSE technique, and the signal intensity ratio of the 2 components was calculated. The ratio was significantly higher in the AA group than in the other groups (AA vs. MDS, P = 0.0209, AA vs. normal controls, P = 0.0143). The present technique appears promising for quantitative assessment of the intramedullary cell density.

Adolescent↗
PubMed1993

Acute eosinophilic pneumonia evaluated with high-resolution computed tomography.

We describe two cases of acute eosinophilic pneumonia (AEP) presenting with high fever and hypoxia of acute onset with bilateral interstitial infiltrates on chest roentgenograms. Diagnosis was confirmed in each case by bronchoalveolar lavage and transbronchial lung biopsy in which the pathologic process was limited to the lung interstitium. High-resolution computed tomography (HRCT) of the thorax at the height of the disease process revealed peripheral ground-glass opacities along the bronchovascular bundles. Symptoms and radiologic abnormalities resolved spontaneously within two weeks. The HRCT-findings may reflect the pathologic process in AEP and the ground-glass opacities likely indicate spontaneous resolution without corticosteroid therapy.

Acute Disease↗
PubMed1990

[MR imaging of aortic arch anomalies--an analysis of MR visualization of ductus arteriosus].

MR imaging of 10 patients with aortic arch anomaly was performed on a 1.0 T system. Coronal and sagittal images with a 5 to 6-mm-thick slice were taken in each patient and the visibility of the ductus arteriosus (ductus ligament) was detected on the sagittal images including its anatomical connection between the pulmonary trunk and arch vessel. The result indicates that MR imaging is of great help for detection of the ductus in case of aortic arch anomaly.

Adult↗
PubMedDate not supplied

MR appearance of pulmonary metastatic calcification.

We report a case of metastatic pulmonary calcification that showed hyperintense signal on T1-weighted MRI. This uncommon MR appearance of calcification is similar to the MR characteristics of calcification in the brain due to abnormal calcium metabolism.

Calcinosis↗
PubMedDate not supplied

Left midcardiac border of frontal chest radiographs of patients with annulo-aortic ectasia.

The utility of the frontal chest radiograph for the diagnosis of annulo-aortic ectasia (AAE) was evaluated in 12 patients with Marfan's syndrome and five patients with incomplete stigmata (forme fruste). Prominence of the left midcardiac border was seen in 11 patients: the upper midsegment in one, the lower midsegment in two, and the whole midsegment in eight patients. Either a linear or an arcuate contour was seen. The contours of the prominent left midcardiac border in three patients who had moderate to marked aortic regurgitation and a cardiothoracic ratio (CTR) over 59% were nonspecific. In the remaining eight patients (47%), the contour was considered to be characteristic of AAE, as suggested by the displacement of either all or part of the right ventricular outflow tract, main pulmonary artery and left atrial appendage. Six patients showed only left midcardiac border prominence. The contour of the left midcardiac border on the conventional frontal chest radiograph is characteristic and of paramount importance for the diagnosis of AAE in Marfan' s syndrome or its forme fruste, particularly in patients whose CTRs are within the normal range.

Adolescent↗