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T Mamiya

Publications and source records attributed to T Mamiya.

At least 19 recordsLinked to original sources
PubMed1995

An approach to cerebral vasodilatory capacity in unilateral and bilateral cerebrovascular diseases using radiolabeled human serum albumin.

The acute cerebrovascular response to acetazolamide was assessed using a blood pool agent and planar dynamic imaging to evaluate cerebral vasodilatory capacity. Ten normal subjects and 12 patients with unilateral or bilateral cerebrovascular disease were studied. After the injection of radiolabeled human serum albumin, dynamic imaging of the anterior view of the head was started. Ten minutes later, 1000 mg of acetazolamide was infused. The dilatation index (the percent increase in activity at the peak response) was obtained for each cerebral hemisphere. The mean dilatation index in normal subjects was 17.1 +/- 3.2% (N = 20). The value was significantly lower in patients with multiple infarcts (7.7 +/- 1.1%, N = 8, P < 0.001), and below the normal range in two involved hemispheres of five patients with unilateral occlusive carotid artery disease and in three hemispheres of three patients with moyamoya disease. It was suggested that this simple method may be useful in assessing cerebral vasodilatory capacity in both unilateral and bilateral diseases.

Acetazolamide↗
PubMed1994

Impaired hepatic function in segmental biliary obstruction demonstrated with a receptor-binding radiotracer.

A patient with cholangiocarcinoma underwent left-sided cholangiojejunostomy, and hepatic functional imaging with a receptor-binding radiotracer and SPECT was performed to evaluate the distribution of functional reserve. It revealed decreased accumulation in the regions with residual dilatation of the intrahepatic bile ducts, indicating several kinds of focal damage in hepatic function caused by segmental biliary obstruction. The radioligand may be useful in assessing regional hepatic function, and the high spatial resolution provided by SPECT appears to play an important role for this purpose.

Aged↗
PubMed1994

Abnormal sympathetic innervation of the heart in a patient with myotonic dystrophy detected with I-123 MIBG cardiac SPECT.

Iodine-123 MIBG is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. The authors report a patient with myotonic dystrophy whose I-123 MIBG SPECT revealed accelerated washout of I-123 MIBG from infero-posterior and a part of lateral wall, although Tl-201 SPECT showed no abnormal finding. The authors conclude that I-123 MIBG can be more sensitive in detecting the cardiac abnormality than Tl-201 SPECT in this disease.

3-Iodobenzylguanidine↗
PubMed1994

Background correction in estimating initial renal uptake. Comparison between Tc-99m MAG3 and Tc-99m DTPA.

A gamma camera method with no blood sampling assesses differential renal function based on initial renal uptake, and requires background correction. The effect of background correction on estimates of initial renal uptake was compared on renograms using Tc-99m MAG3 and Tc-99m DTPA renographies in 14 patients. Renal counts for 2-3 minutes were obtained using three sets of regions of interest (ROIs): rectangular renal and subrenal background ROIs, rectangular renal and perirenal background ROIs, and hand-drawn renal and subrenal background ROIs. Correlations between estimates of initial renal uptake by the three methods were higher for Tc-99m MAG3 renography than for Tc-99m DTPA imaging, suggesting higher reproducibility in evaluating differential renal function using Tc-99m MAG3 renography and a gamma camera method. Although the ratio of counts in the suprarenal area to those in the subrenal area was significantly higher for the right side in the Tc-99m MAG3 study, probably because of hepatic activity, the relative uptake in the right kidney for Tc-99m MAG3 did not differ from that for Tc-99m DTPA. Initial uptake of Tc-99m MAG3 was well correlated with, and about threefold that, of Tc-99m DTPA. It was suggested that initial renal uptake of Tc-99m MAG3 may be an alternative to that of Tc-99m DTPA, with less dependence on background correction in evaluating differential renal function.

Gamma Cameras↗
PubMed1992

[Two-dimensional time-of-flight MR angiography of mediastinum and pulmonary hilar vessels: initial clinical experiences].

Two-dimensional time-of-flight magnetic resonance angiography (2D TOF MRA) of mediastinal and pulmonary hilar vessels was performed in 10 patients, seven men and three women with a mean age (range) of 65.7 (48-88) years. The rate of visualization of the vessels and the diagnostic ability of 2D TOF MRA were assessed in comparison with contrast-enhanced CT. A radiofrequency-spoiled gradient echo sequence (SPGR) was used during repeated breath-holding (8-27 seconds) in coronal (8 patients) and axial (2 patients) imaging planes on a 1.5 Tesla superconducting scanner under the following conditions: repetition time/echo time/flip angle/excitation: 25-33/7-8 ms/45 degrees/1, field-of-view: 30 x 30 cm, slice thickness: 2.5 mm, 32 slices, 256 (frequency) x 192 (phase) matrix, with gradient moment nulling technique. Visualization sufficient to enable diagnosis of the vascular lesion was obtained in 95 (52%) vessels, mere visualization in 63 (35%), and non-visualization in 24 (13%) of the 182 evaluable vessels. The rates of good visualization of pulmonary hilar vessels (26/86, 30%) and veins (26/48, 54%) were significantly lower than that of arteries (43/48, 90%, p < 0.05). The sensitivity and specificity of 2D TOF MRA were 77% (10/13) and 100% (83/83), respectively, in 96 evaluable vessels of nine patients. 2D TOF MRA of mediastium and pulmonary hili is clinically feasible, and may be useful because of its high specificity.

Aged↗
PubMed1992

Value of three-dimensional surface display of brain perfusion imaging. Comparison with tomographic imaging.

The diagnostic ability of a three-dimensional surface display of I-123 IMP brain scintigrams and tomographic images was compared in 12 patients who underwent I-123 brain tomography for cerebral cortical hypoperfusion. Foci of decreased accumulation were independently diagnosed by four radiologists, first with transaxial images, second with three-dimensional images, and finally with both images subjectively compared for the purpose of diagnosing the existence, localization, and extent of lesions. Six different lesions (0 to 3 lesions/radiologist) were found only on the transaxial images, but 30 different lesions (1 to 14 lesions/radiologist) were found on the three-dimensional images. In 9 out of 12 cases, the three-dimensional images were regarded as superior for evaluating the extension of the lesion and for lesion existence and lesion localization in 5 out of 12 (P less than 0.05). In conclusion, a three-dimensional display of an I-123 IMP brain tomogram is superior to tomographic images in diagnosing the extent of cerebral cortical hypoperfusion. However, the display is not superior to tomographic images for diagnosing the existence and localization of hypoperfusion.

Amphetamines↗
PubMed1992

[Activation of aerobic bacteria used as BOD measurement of seawater].

Waste of seawater used for cooling water for machines in some kinds of industries in a littoral district in Sakai City, comes under the application of BOD control of the pollution control ordinance in Osaka Prefecture. But unfortunately the BOD measurement method of seawater sample has not been established. In order to establish the measurement method, we studied the strength of activation of aerobic bacteria in the incubation water used and the dilution water. From our results it was proved that we can use the incubation seawater consisting of more than 10(3) cells/ml general bacteria count and more than 0.50 microgram/l ATP (Adenosin triphosphate) as the incubation water and the artificial seawater as the dilution water.

Adenosine Triphosphate↗
PubMed1992

[A case of meningioma with non-accumulation of 99mTc-ECD and increased accumulation of 99mTc-HMPAO in the tumor].

99mTc-ECD SPECT and 99mTc-HMPAO SPECT with or without Matas test were performed in a 62-year-old woman with meningioma in the left anterior cranial fossa. After injection of 740 MBq 99mTc-ECD or HMPAO, 64 projection images were collected with a rotating Gamma camera. Matas test was carried out by compressing the left common carotid artery for about one minute immediately after RI injection. Although 99mTc-ECD SPECT showed non-accumulation in the tumor, 99mTc-HMPAO SPECT demonstrated increased accumulation in it. This area of increased accumulation disappeared on 99mTc-HMPAO SPECT with Matas test which causes decrease in blood flow of the tumor. These findings suggest 99mTc-ECD and 99mTc-HMPAO have a different mechanisms of accumulation in the meningioma.

Cysteine↗
PubMed1992

[Three-dimensional display of 99mTc-MIBI myocardial scintigraphy].

One of 99mTc-hexakis, 99mTc-methoxyisobutyl isonitrile (MIBI), has been demonstrated to have a myocardial uptake proportional to regional coronary blood flow. In this study, 99mTc-MIBI myocardial scintigraphy were performed for 16 patients with ischemic heart disease. After injection of 740 MBq of 99mTc-MIBI, 64 projection images were collected during a 360-degree rotation. Three-dimensional (3D) display of the left ventricle was reconstructed with depth-shading method from 99mTc-MIBI SPECT images, which were reconstructed by filtered back projection method. In 9 of the patients, left ventricular cineangiography were performed as diagnostic gold standard. Four physicians blinded to patients' clinical informations interpreted 3D images and SPECT images on separate occasions. Diagnosis of hypoperfusion by 3D displays agreed with those of SPECT in 92.9% (104/112 segments), and disagreed in 7.1% (8 segments). Sensitivity and specificity of 3D images were 87.0 and 93.9%, which were not statistically different (p less than 0.05) from that of SPECT images (91.3, 97.0%). Receiver operating characteristic (ROC) analysis revealed nearly identical curves for the two. Although 3D display had nearly identical diagnostic ability with SPECT, observers reported that 3D images were easier to diagnose than SPECT images. An advantage of the 3D display is that the display gives a more realistic impression of the left ventricle to an observer than tomography or planar imaging. Another advantage is that 3D display can reduce the amount of data storage compared with that of SPECT. In conclusion, 3D images may be useful for diagnosis of hypoperfusion of left ventricle.

Adult↗
PubMed1991

[Developmental changes in normal images of 123I-IMP brain SPECT in young children].

In an attempt to determine the normal evolution of N-isopropyl p-I-123-iodoamphetamine (123I-IMP) single photon emission computed tomography (SPECT), we selected 12 children (an age range of 1 month-3 year) who were diagnosed as normal in follow-up between 6 month-3 year by neurological examination, X-ray computed tomography, electroencephalography and 123I-IMP SPECT in our 78 cases. SPECT of the brain was performed 30 minutes after intravenous administration of 74 MBq (2 mCi) 123I-IMP using a rotating gamma camera equipped with a 30-degree slant-hole collimator. In neonates, a predominant activity was observed in the basal ganglia and thalamus, with only slight parietal and occipital activity. Frontal cortex was barely recognizable. Under 1 year, cortical activity was gradually increased and clearly visible. After 1 year, SPECT images were similar to those of adult. In conclusion there was an important modification of the regional perfusion pattern in relation to brain maturation.

Amphetamines↗
PubMed1991

Gallium scintigraphy in neoplastic angioendotheliosis of the lung.

A case of neoplastic angioendotheliosis of the lung is reported. A 56-year-old man presented with a 2-month history of fever, increased serum lactic dehydrogenase, and arterial hypoxemia. Chest radiography revealed diffuse reticulonodular opacity, whereas CT scanning showed diffuse small nodular areas of increased attenuation with indistinct borders. Diffuse pulmonary uptake of Ga-67 was noted in scintigraphy. Combination chemotherapy designed for lymphoma induced a remission of the disease.

Gallium Radioisotopes↗
PubMed1991

Cinematic three-dimensional surface display of cardiac blood pool tomography.

A method of three-dimensional cinematic display (3D cine) of cardiac blood pool tomography is described. ECG-gated transaxial blood pool imaging was obtained from a set of projection images that were collected from 32 images with 10 ECG-gated images per projection during a 180 degrees arc of a rotating gamma camera. A surface contour of the blood pool was determined by a set of isocount lines (40-55% of the maximum pixel counts) of the transaxial images. 3D cine was made by a depth-shading method, in which brightness of a given point on the contour was set proportional to the distance between the viewing plane and the point and to the incident angle formed by the viewing line and the surface of the point. In 15 patients, 3D cine showed hypokinesia, akinesia, dyskinesia, ventricular aneurysm, and opposite motions of the atria and ventricles. Diagnoses of left ventricular motion by 3D cine agreed well with those by echocardiography and contrast left ventriculography.

Aged↗
PubMed1991

[The group study of diagnostic efficacy of cerebro-vascular disease by I-123 IMP SPECT images obtained with ring type SPECT scanner--the ROC analysis on the diagnosis of perfusion defect and redistribution].

We performed two image reading experiments in order to investigate the diagnostic capability of I-123 IMP SPECT obtained by the ring type SPECT scanner in cerebro-vascular disease. Fourteen physicians diagnosed SPECT images of 55 cases with reference to clinical neurological informations, first without brain XCT images and second with XCT images. Each physician detected perfusion defects and redistributions of I-123 IMP and assigned a confidence level of abnormality for these SPECT findings by means of five rating method. From results obtained by ROC analysis, we concluded as follows: (1) Generally, I-123 IMP SPECT is a stable diagnostic modality in the diagnosis of cerebro-vascular disease and the image reading of XCT had no effects on the diagnosis of SPECT on the whole of physician, (2) However, there were unnegligible differences among individuals in the detectability of findings and the effect of XCT image reading, (3) Detectability of redistribution of I-123 IMP was lower than that of perfusion defect and inter-observer variation in the diagnostic performance for redistribution was larger than that of perfusion defect. The results suggest that it is necessary to standardize diagnostic criteria among physicians for redistribution of I-123 IMP.

Amphetamines↗
PubMed1990

[Clinical significance of I-123 IMP brain SPECT in children with brain diseases].

Single photon emission computed tomography (SPECT) of the brain using N-isopropyl p-I-123-iodoamphetamine (I-123 IMP) was performed in 43 children with suspected brain diseases. Forty-three children (25 males and 18 females), with an age range of 24 days-15 years (mean: 6.6 years), were included in the study. Six patients were subsequently diagnosed as normal. Early SPECT of the brain was performed 30 minutes after intravenous administration of 74-111 MBq (2-3 mCi) I-123 IMP using a rotating gamma camera equipped with a 30-degree slant hole and medium energy collimator. Transverse images were reconstructed by Shepp-Logan filtered back projection method with attenuation correction after spatial filtering using an 8th order Butterworth-Wiener filter. Findings of I-123 IMP SPECT were compared with those of X-ray computed tomography (CT) and electroencephalography (EEG). The results showed that 1) In I-123 IMP SPECT, abnormality was found in 30 out of 37 children with brain diseases. The incidence of abnormal findings in the 37 patients was 81% in I-123 IMP SPECT, 61% in X-ray CT, and 78% in EEG., 2) In both cryptogenic and secondary epilepsy, the incidence of abnormality was higher in I-123 IMP SPECT than in X-ray CT. (70% and 94% vs 50% and 81% respectively). Epileptic foci detected by EEG did not correspond with defects found using I-123 IMP SPECT in 27% of the patients., 3) In asphyxiated infants, a high incidence of abnormality was observed on both I-123 IMP SPECT (86%) and X-ray CT (86%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[The experience of a new double-catheter introducer for simultaneous bilateral internal iliac angiography].

We developed a new 8F catheter-introducer system designed for simultaneous insertion of two catheters into each internal iliac artery via a single puncture. This introducer has a common distal limb and a pair of proximal limbs connected in a Y-shaped fashion. Each of the proximal limbs has its own check valve and flushing side arm, through which one can pass two catheters separately. We succeeded in placing each of two catheters at desired sites in three cases of pelvic angiography. This system will be of great help in pelvic angiography and infusion-chemotherapy when bilateral catheterization is required.

Aged↗
PubMed1990

[Generation of brain scintigram reports with a speech recognition device controlled by a personal computer].

Radiology reporting system using a speech recognition apparatus was applied to generation of reports on brain scintigram and SPECT. The number of words or phrases that were selected for the reporting system by the authors was 259. Rates of correct recognition at the first, second, and third or more utterance of the voices were 91.1, 5.0, and 3.9%, respectively. The recognition rates decreased from 96.6 to 88.0% when the mean lengths of the words or phrases varied from 6.4 to 3.3. Net time for the generation of 8 reports by the system was 21 minutes 26 seconds, while that by the traditional dictation-transcription method was 15 minutes and 53 seconds. This system seems to be useful because of much longer input time expected for an average doctor, who usually is not well trained in using a Japanese-word processor, and convenience for database management offered by the system.

Brain↗
PubMed1990

[Treatment of priapism by caverno-spongio-anastomosis].

We experienced two cases of priapism; one, idiopathic and low flow type, the other post-traumatic and high flow type. We tried caverno-spongio-anastomosis (CSA) as an operative treatment in both cases. Postoperative courses were uneventful. We suggest that CSA is a simple and reliable treatment of priapism.

Adult↗