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S Noma

Publications and source records attributed to S Noma.

84 records · Page 5Linked to original sources
PubMedDate not supplied

Posterior lobe of the pituitary in diabetes insipidus: MR findings.

The posterior lobe of the pituitary gland was evaluated by 1.5 T magnetic resonance (MR) in five cases of diabetes insipidus (DI), including one primary (idiopathic) and four secondary DI cases due to germinomas (two), teratoma (one), and histiocytosis X (one). The normal posterior lobe displays high signal indistinguishable from fatty tissue on T1-weighted images (T1WI) (short T1 value). In all five DI cases the normal high signal of the posterior lobe was not detected in the pituitary fossa on T1WI. Hence, because of this characteristic finding, MR may greatly assist in the diagnosis of DI. We may speculate that the short T1 value of the posterior lobe is closely related to its functional integrity and may be due to the neurosecretory materials in the axons of the hypothalamohypophyseal tract.

Adolescent↗
PubMedDate not supplied

MR imaging of thyroid hemochromatosis.

We present the magnetic resonance (MR) images of exogenous hemochromatosis in the thyroid gland. On both T1-weighted images and T2-weighted images the thyroid showed low intensity similar to that of the background. Magnetic resonance is of value in imaging the tissue deposition of iron. In assessing thyroid iron accumulation, MR is superior to CT because CT can not differentiate iron deposition from normal iodine concentration.

Adult↗
PubMedDate not supplied

Hyperintense signal of the posterior pituitary on T1-weighted MR images: an experimental study.

The origin of the hyperintense signal (HIS) of the pituitary gland posterior lobe (PL) on T1-weighted magnetic resonance (MR) images was investigated. Six rabbits were imaged on a 1.5 T device before and after 2 weeks' feeding of hypertonic saline solution (phase I). Two were killed soon after the second imaging; the pituitary gland was examined histochemically for neurosecretory granules containing antidiuretic hormone (ADH). The other four rabbits were given regular water for another 2 weeks (phase II) and then were again imaged. The plasma ADH level was monitored at each imaging session. In all subjects, the signal intensity of the PL decreased at the end of phase I, and the HIS reappeared at the end of phase II. The neurosecretory granules in the PL significantly diminished in number in phase I. Plasma ADH levels significantly increased in phase I and returned to their normal range in phase II. These clear correlations between MR findings and hormonal and histochemical results strongly suggest that the source of the HIS of the PL is the neurosecretory granules containing ADH.

Animals↗
PubMedDate not supplied

Primary thyroid lymphoma: MR appearance.

Magnetic resonance imaging was evaluated in six patients with primary thyroid lymphoma. Five patients had a solitary localized tumor and one had multiple tumors. These masses showed homogeneous iso- or high intensity compared with the uninvolved thyroid tissue on T1-weighted images and homogeneous high intensity on T2-weighted images. Diffuse lobulated goiter with homogeneous intensity was seen in the sixth case, where the differentiation between lymphoma and Hashimoto thyroiditis was impossible. Extrathyroidal tumor extension occurred in two cases and cervical lymphadenopathy in one case. In five of six cases, identification and staging of primary thyroid lymphoma were possible with MR imaging. Magnetic resonance imaging was comparable to CT in the detection of tumors (five cases), extrathyroidal extension (two cases), and cervical lymphadenopathy (one case). In three cases, the pseudocapsule (a low-intensity band forming the border between tumor and thyroid tissue) was detected only by MR imaging. In one case, the discrimination between tumor and uninvolved thyroid gland was clearer on MR imaging than on CT.

Adult↗
PubMedDate not supplied

Comparison of fixed and adjustable window width and level settings in the CT evaluation of diffuse lung disease.

OBJECTIVE: The purpose of this investigation was to assess the utility of allowing free adjustment of window width and level in comparison with the use of a fixed lung window in the CT evaluation of diffuse lung disease. MATERIALS AND METHODS: Six radiologists each judged 36 cases (28 diffuse lung disease and 8 normal) using a standardized form. In half of the sessions, images were viewed in a fixed lung window (level = -500 HU; width = 2,000 HU). In the other sessions, the observer was able to adjust the window and level freely while viewing the images. Each case was seen twice in separate sessions: once in a fixed lung window and once with window width and level adjusted by the reader. A variety of diagnostic features were evaluated using a 5 point scale. These included visibility of fine lung structures, abnormalities of the lung parenchyma, and overall evaluation of the lung. RESULTS: The visibility of lung structures was not improved with adjustable window settings. Receiver operating characteristic (ROC) analysis showed fixed windows to be superior to adjustable windows for overall evaluation of the cases [fixed A(z) = 0.90, adjustable A(z) = 0.84, p < 0.05, jackknife method]. Time to rate each case was increased by 15% with window width and level adjustment. CONCLUSION: Free adjustment of window width and level produced no improvement in reader performance over that achieved with fixed window width and level.

Humans↗
PubMedDate not supplied

Thin-section CT features of intrapulmonary lymph nodes.

PURPOSE: The objective of this study was to evaluate CT findings of pathologically proven intrapulmonary lymph nodes (IPLNs) and discuss the utility of thin-section CT and contrast-enhanced CT. METHOD: CT findings of 18 nodules in 14 patients with pathologically proven IPLNs were reviewed. CT scanning of the whole lung was performed contiguously with slice thickness of 10 mm. In addition, a helical scan with slice thickness of 2 mm was performed in nine patients, focusing on the nodule. Contrast-enhanced helical CT was performed in four patients, and the utility of thin section CT and contrast-enhanced CT was investigated. RESULTS: One patient had three nodules, 2 patients had two nodules, and the remaining 11 patients had a solitary nodule. All nodules were located below the level of the carina and within 15 mm of the pleura. In one case, conventional CT revealed the nodule 20 mm away from the pleura; however, the nodule attached to the major fissure was clearly revealed on thin-section CT. The size of the nodules was < or =15 mm, and the shape was round (n = 8), oval (n = 9), or lobulated (n = 1) with sharp border. One nodule demonstrated a spiculated border due to a surrounding pulmonary fibrosis on conventional CT; however, thin-section CT showed precisely a sharp border. The lobulated shape of one case histopathologically reflected a hilus of lymph node. On contrast-enhanced helical CT, all four nodules were enhanced and the degree enhancement was 36-85 HU (median 66.6 HU). CONCLUSION: In current times, IPLNs are not uncommon lesions. We should consider IPLN in the differential diagnosis of solitary or multiple pulmonary nodules in the peripheral field and below the level of the carina. Thin-section CT showed precisely the border or relation between IPLNs and the surrounding structure. It was difficult to distinguish between IPLNs and malignant nodules from the degree of enhancement on contrast-enhanced CT. On thin-section and contrast-enhanced CT, the findings of IPLNs are not necessarily specific. Therefore, strict observation on CT is necessary; in certain cases that are increasing in size, video-assisted thoracic surgery should be considered because of their location.

Adult↗
PubMedDate not supplied

CT findings of BALTOMA.

OBJECTIVE: To review the CT findings of BALTOMA, a low-grade malignant lymphoma originating from bronchus-associated lymphoid tissue (BALT). METHODS: The CT findings, symptoms, and clinical courses of BALTOMA in five patients were reviewed. The specimens obtained at operation were investigated, and the pathological findings were compared with the CT findings. RESULTS: There were no symptoms in four patients and normal laboratory data in all patients. One patient who complained of general malaise underwent surgery under suspicion of lung carcinoma. Four patients were observed from 4 months to 7 years and 1 month under the diagnosis of organizing pneumonia or chronic inflammatory processes. On CT images a localized lesion was seen in four cases, while multiple lesions were seen in one case. Attenuation of the lesions was between 39.15 and 60 HU on nonenhanced CT. Lesions were homogeneously enhanced by contrast material. The margins of the lesion were clearly demarcated by interlobular septa in one portion and were unclear in the other portion in all cases. Air bronchograms were seen in four cases. CT angiogram signs were seen in three of four cases in which contrast study was performed. There was no lymphadenopathy, pleural changes, or invasion to other organs. The pathological investigation revealed small lymphocytes that showed monoclonality in all cases. CONCLUSIONS: Awareness of the CT findings of BALTOMA can help to avoid misinterpreting BALTOMA as chronic inflammation and/or lung carcinoma. When a slowly progressive chronic pneumonia is being followed up, transbronchial lung biopsy and immunoglobulin staining of lymphocytes should be recommended for the correct diagnosis.

Aged↗
PubMedDate not supplied

Systemic arterial supply to normal basilar segments of the left lower lobe: role of continuous thin sliced CT.

A rare congenital anomaly of the left lower pulmonary artery is presented. A 39-year-old woman was admitted to our hospital for evaluation of a splenic mass. Abdominal CT disclosed abnormal vessels in the left lower lobe. Angiography revealed a large systemic artery from the descending aorta supplying the basilar segments of the left lower lobe. Continuous thin sliced CT revealed the anatomical details of this anomaly and showed that the tracheobronchial tree had a normal connection with the lung parenchyma. Although the volume of the left lower lobe was reduced, there were no symptoms related to this lesion. Since the splenic lesion was malignant lymphoma limited to the spleen, only splenectomy was performed. In spite of intensive systemic chemotherapy following the operation, there were no pulmonary complications. Although surgery may be necessary in the future, observation alone has been carried out for more than 3 years because of the lack of symptoms and normal pulmonary function. Continuous thin sliced CT was useful in evaluating this anomaly.

Adult↗