Biomedical subjects

I Narabayashi

Publications and source records attributed to I Narabayashi.

At least 55 records · Page 3Linked to original sources

PubMed1995

[Clinical usefulness of dipyridamole loading 99mTc-tetrofosmin myocardial scintigraphy].

This study performed to establish the most suitable method in one-day protocol and to evaluate clinical usefulness of 99mTc-tetrofosmin myocardial scintigraphy after dipyridamole infusion. Image quality and liver overlapping of the myocardial SPECT were evaluated in 107 patients with old myocardial infarction (42 cases), angina pectoris (53 cases) and others (12 cases). Left ventricular wall motion and coronary artery stenosis were compared to myocardial uptake score in 55 patients who received cardiac catheterization. The suitable image quality was acquired in early SPECT images using 259 MBq of 99mTc-tetrofosmin. The overlapping between inferior wall and liver uptake was able to minimize over 45 minutes interval from injection of 99mTc-tetrofosmin to data acquisition. The segments of normal wall motion had no perfusion defect of the myocardial SPECT in all cases (100% (148/148)). The segments of abnormal wall motion had decreased myocardial uptake of the myocardial SPECT (77% (24/31)). The agreement between coronary artery stenosis and decreased myocardial uptake was 96% (24/25) in right coronary artery, 87% (26/30) in left anterior descending coronary artery and 83% (19/23) in left circumflex coronary artery. These data suggests that image quality of dipyridamole loading 99mTc-tetrofosmin myocardial scintigraphy. Myocardial perfusion in the 99mTc-tetrofosmin myocardial scintigraphy is good correlation to both left ventricular wall motion and coronary artery stenosis.

Adult↗

PubMed1995

[Comparative examinations of serum pepsinogen I, II and gastric area using computed radiography in the atrophic gastritis].

The relationship between serum PG I, PG II levels and extent of atrophic gastritis was examined. On 64 patients (male: 32, female: 32, 51.9 years old on average) with established diagnosis of either atrophic gastritis or normal. In the X-ray gastric examination, Fuji Computed Radiography (FCR) was used to obtain clear-cut images of the gastric area. Concerning the serum PG I level, patients in the group with atrophic gastritis showed lower levels than those of the people in the group with no atrophic change, but the variation was wide, and no definite tendency was seen in the relationship between the atrophic change and the serum PG I levels. Concerning the serum PG II level, as the atrophic change progresses, the serum PG II level tended to increase gradually. A significant reduction in the PG I/II ratio was seen in the group with atrophic changes (p < 0.01) in comparison with the group with no atrophic changes, and the PG I/II value tended to decrease. In conclusion, as a relationship between the atrophic change and the serum PG levels had a wide variation, we considered to be difficult by to measure the serum PG level to understand the presence and extent of the atrophic gastritis.

Disease Progression↗

PubMed1994

[Three-dimensional CT imaging of pulmonary nodules using helical scan CT].

To evaluate the usefulness of three-dimensional (3D) imaging of pulmonary nodules from helical scan CT images, 3D reconstructions were performed in 23 patients, using a CEMAX VIPstation. These cases included 15 lung cancers, six metastatic lung cancers, an aspergilloma and a tuberculoma. The equipment used was a Toshiba CT system, the X force. Helical scan CT data were acquired using up to 20 continuous 1.5 sec rotations with an X-ray beam width of 5 mm and a couchtop movement speed of 5 mm/1.5 sec, and during a single breath-hold. Axial images were reconstructed at a section interval of 2 mm. Helical scan CT permits axial images to be reconstructed at any desired position within the scanned area, and provides images without interslice gaps caused by respiratory movement. Therefore, high-quality 3D images can be obtained from these data. Concerning the optimum threshold range of CT number of 3D reconstruction, we clarified the lower and upper limits (lower/upper), as follows: 1) Solid pulmonary nodule: (-700-(-)400/-100 HU) 2) Tumor invaded to pleura or chest wall: (-700-(-)400/-200 HU) 3) Pulmonary nodule with cavity: (-700-(-)400/50 HU) 4) Small pulmonary nodule (< 10 mm): (-750-(-)600/-100 HU) In all cases, it was possible not only to demonstrate abnormal findings three-dimensionally, but also to grasp anatomical relationships among the pulmonary nodule, bronchi, vessels and chest wall. In conclusion, it was considered that 3D CT imaging provided additional anatomical information and was very useful.

Adenocarcinoma↗

PubMed1994

[Clinical evaluation of asymmetric film-screen system for thoracic lesions].

We investigated the clinical usefulness of the asymmetric film-screen system on postero-anterior chest roentgenograms for thoracic lesions. The asymmetric film-screen system, the so-called Kodak Insight thoracic imaging system, records a different image on each side of double-emulsion film. An image displaying the lung field is captured on the anterior side of the film, while one displaying the mediastinal, retrocardiac and retrodiaphragmatic structures is captured on the posterior side. The clinical usefulness of the asymmetric film was evaluated in 20 patients for visibility of the anatomical structures and abnormal lesions in comparison with conventional film. In the asymmetric film-screen system, the front and rear screens were HC (high contrast) and Regular, respectively. Chest radiography was performed at 200mA and 100kVp. As conventional film, we used SRC film (Konica, orthotype film), and chest radiography was performed at 100mA and 130kVp. The chest roentgenograms obtained with the asymmetric film-screen system provided better information on normal structures and abnormal lesions in the lung field, but slightly inferior information on mediastinal structures. In conclusion, it was considered that the asymmetric film-screen system was useful for thoracic lesions.

Aged↗

PubMed1994

[Contrast enhancement effect of new oral agent (blueberry juice) for upper abdominal MR imaging].

Manganese is known to affect relaxation times. Blueberry is naturally rich in manganese, and oral contrast effect by its squeezed juice (B. J) was expected. At some appropriate concentration of manganese within daily intake level, B. J worked as positive contrast agent on T1WIs and negative one on T2WIs simultaneously without any side effects. The negative effect on T2WIs could reduce ghost artifacts from motion of high intensity structures. B. J improved confirmation of gastroduodenal tract regardless of field strength and could be adapted for fast SE. We introduced a preliminary examination of B. J as an oral contrast agent for upper abdominal MRI.

Abdomen↗

PubMed1994

Evaluation of the ventilation-perfusion ratio in lung diseases by simultaneous anterior and posterior image acquisition.

Ventilation and perfusion images were acquired during tidal breathing using 81mKr gas and 99mTc-MAA. Anterior and posterior functional images of V/Q and Q/V were simultaneously acquired in 34 subjects with various lung diseases and 6 healthy controls. Superimposed anterior and posterior images were constructed and histograms of the frequency distribution for ventilation, perfusion, and the V/Q ratio were displayed for both lungs as well as for the left and right lungs individually. Blood gas analysis and general lung function tests were also performed on the day before scintigraphy. A correlation between marked uneven distribution of V/Q and A-aDO2 was found. When the proportion of counts at V/Q < 0.67 and/or V/Q > 1.50 in the V/Q counts histogram was compared with A-aDO2, there was a significant positive correlation for anterior images (r = 0.684, p < 0.05), posterior images (r = 0.654, p < 0.05) and superimposed images (r = 0.696, p < 0.05). Superimposed images therefore showed the highest correlation. There was no correlation between the results of lung function testing and A-aDO2. Coronal SPECT images were also obtained in 15 patients and compared with the superimposed anterior and posterior planar images. There was a good correlation (r = 0.888, p < 0.001) between both the imaging methods regarding the marked uneven distribution of V/Q. Simultaneous anterior and posterior planar image acquisition reduces the examining time, is simple, and is noninvasive. The present results also suggest that it is useful for quantitative evaluation of the ventilation-perfusion ratio.

Adolescent↗

PubMed1994

[Assessment of myocardial contraction and relaxation with 99mTc-tetrofosmin multi-gated myocardial SPECT].

Myocardial relaxation at the diastolic phase was not evaluated by multi-gated myocardial SPECT, although myocardial contraction at the systolic phase was studied by percent wall thickening and Bull's eye methods. We make out a myocardial volume curve and report to evaluate the myocardial relaxation using multi-gated myocardial SPECT. The study population consisted of 3 normal human subjects (3 male, 32-37 years old), 10 idiopathic cardiomyopathy, 10 coronary artery disease and 1 hypertensive heart disease combined with aortic regurgitation. All cases were injected 555 MBq of 99mTc-tetrofosmin (Amersham Healthcare Corporation) intravenously at rest. A triple detector gamma-camera (GCA-9300A, Toshiba Medical, Japan) and a data processing computer (GMS-5500A, Toshiba Medical, Japan) were used in this study. A cardiac cycle (R-R interval) was divided by 16 frames (50-80 msec per 1 frame). Eight myocardial volume curves were calculated at the anterior wall, apex and inferior wall of the vertical long axis view and were calculated at the septal wall, apex and lateral wall of the horizontal long axis view, respectively. The patterns of the myocardial volume curves were classified into 5 patterns (Normal pattern (N), Delayed Contraction pattern (DC), Delayed Relaxation pattern (DR), Mixed pattern (M) and Normal pattern with Decreased amplitude (ND)). Myocardial uptake was evaluated visually of grading into severe hypertrophy (5), hypertrophy (4), normal (3), mild hypoperfusion (2), hypoperfusion (1) and perfusion defect (0). We compared patterns of the myocardial volume curves to myocardial uptake in the same segments. It was possible to detect myocardial edge of the total 16 frames with 50-60% threshold in the normal volunteer and in patients with hypertrophic cardiomyopathy and to make a myocardial volume curve. The region of the severe myocardial perfusion defect could be detected with 20% threshold in patients with old myocardial infarction. In comparison with myocardial volume curves and myocardial uptake, 74.6% in the N pattern had a normal uptake (3), 66.7% in the ND pattern had a normal uptake (3), 61.5% in the DC pattern had a hypoperfusion segment (0, 1 or fill-in to normal uptake), 44.4% in the DR pattern had a hypertrophic segment (4, 5 or fill-in to increased uptake). The pattern of myocardial volume curve indicates myocardial contractility and relaxation in each myocardial segment.

Adult↗

PubMed1994

[A comparison among 123I-IMP SPECT, EEG and MRI in patients with temporal lobe epilepsy].

N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) single photon emission computed tomography (SPECT), electroencephalography (EEG), and magnetic resonance imaging (MRI) were performed in 19 patients with temporal lobe epilepsy during interictal stage. MRI demonstrated abnormal signal in mesial temporal lobe (hippocampus) in 10 of 19 patients and 123I-IMP SPECT showed a hypoperfusion area in 15 of 19 patients. When compared with EEG and MRI data, disagreement of the affected area was observed in 3 cases. In comparison of EEG and 123I-IMP SPECT data, disagreement of the affected area was observed in 6 cases. Although there were no disagreement in comparison of MRI and 123I-IMP SPECT. We made a reprojection data parallel to the hippocampus in 123I-IMP SPECT. These data demonstrated obviously a hypoperfusion area around the hippocampus. In cases within one month from seizure attack, wide hypoperfusion area was showed on 123I-IMP SPECT in comparison of abnormal signal area on MRI. It could be considered that a reprojection data parallel to the hippocampus was useful to know extent of hypoperfusion area in temporal lobe epilepsy.

Adult↗

PubMed1994

[A case of malignant lymphoma of the thyroid accompanied by interstitial pneumonitis during radiation therapy after systemic chemotherapy].

We reported a case of malignant lymphoma of the thyroid accompanied by interstitial pneumonitis during radiation therapy after systemic chemotherapy. Thyroid malignant lymphoma is a rare malignant tumor, which usually responds well to irradiation and systemic chemotherapy. Interstitial pneumonitis occurred during radiation after systemic chemotherapy. In this case, irradiation was simultaneously done with the chemotherapy. The radiation field included the neck and upper mediastinum. Chest X-ray showed multiple patchy shadows in both the middle and lower lung field, and it changed to contraction shadows after steroid pulse therapy. 67Ga scintigram showed multifocal increase of uptake, when chest X-ray patchy shadows were seen only in the middle and lower lung fields. 67Ga scintigraphy and CT were considered useful for evaluation of drug-induced interstitial pneumonitis.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1993

[Clinical evaluation of two- and three-dimensional imaging of helical scanning CT in the upper abdomen].

To evaluate the usefulness of helical scanning CT of the upper abdomen, 30 patients with hepatic, adrenal, pancreatic and renal disease were examined using a Toshiba CT system, the Xforce. Helical scanning CT data were acquired using up to 20 continuous 1.5-second rotations, with a 1.5-3 ml bolus injection of contrast medium, and during a single breath-hold. Helical scanning provided both better data continuity and resolution than conventional scanning. The axial images with a slice thickness of 5 mm were not inferior in quality to equivalent images acquired by conventional CT, and multiplanar reconstruction images were superior. Targeted structures could be easily obtained because helical scanning CT permits image reconstruction in any direction. Using a CEMAX-VIPstation, we generated three-dimensional display images of high-density structures from the postcontrast data acquired with helical scanning. On these images, it was easy to observe the high-density tumors three-dimensionally and to determine the position of the tumors relative to the high-density surrounding organs. In conclusion, helical scanning CT was considered to be useful in clinical diagnosis involving the upper abdomen.

Adult↗

PubMed1993

Clinical aspects of primary thyroid lymphoma: diagnosis and treatment based on our experience of 119 cases.

We describe the clinical aspects of primary thyroid lymphoma, particularly diagnostic procedures and successful therapy based on our observation of 119 patients with primary thyroid lymphoma. Thyroid lymphoma occurred exclusively in the thyroid gland of patients with Hashimoto's thyroiditis as a rapidly growing mass in the thyroid gland. Therefore, progressively enlarging goiter and compression symptoms were the most common clinical manifestations. A significant number of patients in our series had subclinical hypothyroidism (14%) or overt hypothyroidism (27%) because of the coexistence of Hashimoto's thyroiditis. Whenever thyroid lymphoma is suspected, we recommend an ultrasound scan of the thyroid gland and fine needle aspiration biopsy as initial diagnostic procedures. Thyroid ultrasound showed characteristic asymmetrical pseudocystic pattern in 43 of the 46 patients (93%), and thyroid cytologic examination showed abundant monomorphic infiltration of lymphoid cells. Among 83 patients who underwent fine needle aspiration biopsy, 65 patients (78.3%) were diagnosed correctly and 10 patients (12%) had borderline cytologic results. Thus, 90% of patients with thyroid lymphoma were diagnosed or the diagnosis suspected based on fine needle aspiration biopsy. To confirm the diagnosis of lymphoma histologically and to determine the degree of malignancy, open biopsy taking 2-3 g tissue should be done for all cases. Treatment of thyroid lymphoma does not require resection of all lymphoma tissue or total thyroidectomy. Our successful treatment is radiation therapy combined with six courses of CHOP chemotherapy (cyclophosphamide, adriamycin, vincristine, prednisolone). This mode of therapy improved the 8-year survival rate to nearly 100% regardless of the histological type of malignancy.

Adult↗

PubMed1993

[A case of benign paraganglioma arising in the middle mediastinum; 201Tl-SPECT for differentiation from malignant tumor].

A case of benign paraganglioma arising in the middle mediastinum was reported. 201Tl SPECT showed high accumulation in tumor on early images at 15 min and reduced on late images at 3 hours after infusion. The patient was a 57 year old female. In the contrast enhanced CT, 3 x 4 cm tumor with intensive enhancement was recognized at the right middle mediastinum. Under the radiological images, the tumor was surgically removed. The pathologic diagnosis was a low atypical nonfunctioning aortico-pulmonary paraganglioma. This report was suggested that 201Tl SPECT was useful for differential diagnosis of benign neurogenic mediastinal neoplasms.

Diagnosis, Differential↗

PubMed1993

[A basic study of multi-gated single photon emission computed tomography with thallium-201].

A Multi-gated SPECT was acquired commonly in 64 x 64 matrix and 8 frames per cardiac cycle (64 x 64/8F). But it was not established that 64 x 64 matrix and 8 frames per cardiac cycle were the most suitable in multi-gated SPECT. Five normal volunteers were examined multi-gated 201Tl SPECT with 5 acquisition modes of 128 x 128 matrix/16 frames, 128 x 128/8F, 64 x 64/32F, 64 x 64/8F using multi-detector SPECT system (GCA-9300). And we calculated percent wall thickening (%WT) [%WT = (ES counts - ED counts)/ED counts] in 9 cases with 64 x 64/8F. The images quality of both 128 x 128/16F and 128 x 128/8F was not clear in compared with images of both 64 x 64/16F and 64 x 64/8F, because the end-diastolic phase of 128 x 128/16F images showed a decreased uptake of 201Tl in the antero-apical region. Although 64 x 64 (8) images had only 8 frames per cardiac cycle, we could observe systolic and diastolic phase and we could calculate %WT. The %WT (M +/- SD) of horizontal long axis images were 48 +/- 15 (sept. basal), 48 +/- 19 (sept. apical), 65 +/- 29 (apex), 49 +/- 22 (lat. apical) and 40 +/- 15 (lat. basal).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

[Clinical efficacy of 99mTc-tetrofosmin myocardial scintigraphy--comparison to 201Tl myocardial scintigraphy].

99mTc-tetrofosmin is a lipophilic, cationic diphosphine which has been developed for myocardial imaging. We examined 9 patients with ischemic heart disease including 3 angina pectoris (AP), 4 old myocardial infarction (OMI), 1 AP with OMI and 1 syndrome X. One patient was examined before and after operation. 370 MBq of 99mTc-tetrofosmin was injected during exercise and 740 MBq at rest. And 74 MBq of 201Tl myocardial exercise and redistribution scintigraphy was also performed to compare with 99mTc-tetrofosmin myocardial scintigraphy. SPECT, multiple gated SPECT and anterior planar images were obtained in all cases. We calculated percent wall thickening (%WT) using multiple gated SPECT images. There was a decreased lung uptake in 99mTc-tetrofosmin planar images compared to 201Tl myocardial scintigraphy. Liver and Biliary system uptake in 99mTc-tetrofosmin images was decreased with intake of milk. Segmental comparison of SPECT images showed an agreement in 9/10 of the segment between 201Tl and 99mTc-tetrofosmin. We could obtain excellent quality of multiple gated SPECT images in all patients. We could calculate percent wall thickening (%WT) in all patients. We conclude that 99mTc-tetrofosmin myocardial scintigraphy should provide usefulness for detection of ischemic myocardium as same as 201Tl myocardial scintigraphy, although the biologic characteristics of two agents were different. These data and excellent quality of multiple gated SPECT images suggest that 99mTc-tetrofosmin is a new 99mTc agent for evaluation of patients with ischemic heart disease.

Exercise Test↗

PubMed1993

[Evaluation of 99mTc-HM-PAO thigh accumulation in patients with cerebro-vascular disease].

99mTc-HM-PAO cerebral SPECT and whole body scintigraphy (WBS) were performed in 5 patients without cerebro-vascular disease (CVD) (Group 1), 31 patients with CVD but not hemiparesis (Group 2) and 18 patients with CVD and hemiparesis (Group 3). Four ROIs were drawn manually around the whole body (WB), brain (Br), right and left thigh (Th). We calculated some ratios: the total counts in the brain over the total counts in the whole body (Br/WB), the total counts in the thigh over the total counts in the whole body (Th/WB) and the mean counts in the thigh over the mean counts in the brain (Th/Br). The Br/WB was 6.9 +/- 1.8%, rt-Th/WB was 4.9 +/- 2.1%, lt-Th/WB was 5.1 +/- 1.3% and Th/Br was 0.46 +/- 0.17 in group 1. Whole body scintigraphies in group 1 revealed clear and similar images between right and left thigh. The Br/WB was 6.7 +/- 1.4%, Th/WB of paretic side was 4.6 +/- 1.0%, Th/WB of non-paretic side was 5.8 +/- 1.2% and Th/Br was 0.47 +/- 0.18 in group 3. The Th/WB in non paretic side was significantly higher than that in paretic side (p < 0.01). The thigh images in group 3 revealed clearly different between paretic and non-paretic thigh. In conclusion we could acquire the clear thigh images with 99mTc-HM-PAO. It was possible that we evaluated not only cerebral perfusion but also muscle atrophy and/or perfusion in patients with CVD using 99mTC-HM-PAO.

Adult↗

PubMed1991

[Enhanced MRI of breast cancer smaller than 3 cm].

Twenty-two patients with breast cancers were studied using magnetic resonance (MR) imaging with a cylindrical surface coil at 1.5 Tesla. All were examined with the FE sequence and Gd-DTPA as a contrast medium. These images were compared with micrographs of the specimens. All cancers were enhanced clearly, and demarcated margins or spiculations of the tumors were seen as clearly on MR images as on micrographs of the specimens. In 12 patients (9 carcinomas, 2 fibroadenomas and 1 benign phyllodes tumor), dynamic studies were performed after the intravenous injection of Gd-DTPA. All nine carcinomas showed enhancement characterized by a sudden increase in signal intensity on the order of 100% or more within the first 2 minutes after injection. Two fibroadenomas were enhanced slowly. Thirteen patients with breast cancers were examined with several sequences (FE, T1-weighed SE, T2-weighed SE and STIR) with or without Gd-DTPA. The most clearly delineated images of the tumors were those of FE images with Gd-DTPA enhancement. A phantom constituted of various concentrations of Gd-DTPA in 20% albumin solution was measured by signal intensities with T1-weighted SE sequence and FE sequence. The ratio of enhancement of the 20% albumin solution relative to the Gd-DTPA concentration was higher with the FE sequence than with the SE sequence. The sensitivity of the FE sequence to Gd-DTPA enhancement was 1.5 times that of the SE sequence under the usual concentration of Gd-DTPA.

Adenocarcinoma↗

PubMed1991

[SPECT images after intravenous injection of 99mTc-DTPA in lung tumors--comparison with delayed 123I-IMP lung scintigraphy].

The aim of this study was to assess the efficacy of SPECT imaging of the thorax with 99mTc-DTPA, which accumulates at sites of increased capillary permeability and expanded extracellular space, by comparing it with delayed 123I-IMP lung scintigraphy. We have previously reported that increased uptake on delayed 123I-IMP lung scintigraphy was associated with atelectasis and inflammation. Thirteen patients with lung cancer (4 with atelectasis and 3 with pleurisy), one patient with malignant lymphoma complicated by pneumonia and pleurisy, and one patient with pneumonia were studied. 99mTc-DTPA scintigraphy was performed twice, 20-160 minutes and 2-4 hours after the intravenous administration of 370 MBq of 99mTc-DTPA. 123I-IMP scintigraphy was performed 24 hours after the intravenous injection of 111 MBq of 123I-IMP. SPECT images were obtained with both types of scintigraphy. 99mTc-DTPA scintigraphy was compared with 123I-IMP scintigraphy for its ability to detect atelectasis and pneumonia. All patients showed increased accumulation corresponding to the lesions on both 123I-IMP and 99mTc-DTPA scintigraphy. 123I-IMP scintigraphy showed a defect corresponding to the tumor with increased accumulation around the tumor, whereas 99mTc-DTPA scintigraphy showed accumulation corresponding to the tumor. Ten of 11 tumors showed accumulation of an intensity equal to that of the soft tissue of the chest wall on 20-60 min 99mTc-DTPA images. The 2-4 hr images showed that 99mTc-DTPA leaked from the periphery of the tumor toward its center. All the patients with pleurisy showed increased accumulation in effusion on 2-4 hr 99mTc-DTPA scintigraphy.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1991

[Clinical value of Gd-DTPA enhanced MRI of pulmonary and mediastinal tumors].

Gd-DTPA (Gd) enhanced Magnetic Resonance (MR) early images and delayed images of 28 patients with pulmonary or mediastinal tumors were analyzed and compared with the computed tomography scans and the plain MR images. Numbers of relative signal intensity of the tumors, secondary lesions (adjacent pneumonia or collapse) and pleural effusions were calculated and graphed on time intensity curves. Gd-enhanced MR early images were more useful than other methods in delineating viable areas from necrotic areas. However, Gd-enhanced MR delayed images better delineated margins of necrotic areas than Gd-enhanced MR early images did in some cases. In distinguishing tumors from secondary lesions, Gd-enhanced MR early images were the most useful, too. We considered Gd gradually penetrated into pleural effusions after intravenous administration, just in the same way into necrotic areas. Therefore pleural effusions showed very high intensity on Gd-enhanced MR delayed images. Time intensity curves of the tumors and pleural effusions showed characteristic patterns, but those of secondary lesions showed different patterns among the individual cases. We presumed this was due to the variances of the water and fibrous components among them.

Adenocarcinoma↗