Biomedical subjects

N Tonami

Publications and source records attributed to N Tonami.

At least 199 records · Page 11Linked to original sources

PubMed1991

Functional advantage of parenchymal-sparing surgery for early hilar lung cancer.

In a group of 27 patients with early hilar lung cancer, standard sleeve lobectomy was performed in 14 cases, standard lobectomy in 9 cases, and another 4 patients underwent parenchymal-sparing operations (2 had sleeve segmentectomy, 1 had sleeve middle lobectomy, and 1 had left second carinal resection). The changes of conventional pulmonary function tests and regional pulmonary function were compared between patients undergoing sleeve lobectomy and those undergoing parenchymal-sparing surgery. The parameters used for the conventional lung function tests were FVC, %FVC, FEV1.0, and %FEV1.0. For the evaluation of regional pulmonary function, perfusion scans using 99mTc-MAA and ventilation scans using 133Xe were performed. The decrease of FVC in the sleeve lobectomy group (n = 5) was 724 +/- 182.7 ml, whereas that in the parenchymal- sparing surgery group (n = 4) was 367.5 +/- 52.1 ml, a significant difference. Both the FEV1.0 and %FEV1.0 showed no marked changes in both groups between the preoperative and postoperative values. Perfusion and ventilation scans in the parenchymal-sparing group showed a superior result in comparison with sleeve lobectomy group. All the patients undergoing parenchymal-sparing operations survived over the long term. It was thus concluded that parenchymal-sparing surgery can be applied to carefully selected patients with tiny localized cancers.

Aged↗

PubMed1991

Thallium-201 SPECT depicts radiologically occult lung cancer.

A case of radiologically occult lung cancer is presented in which 201TI SPECT of the chest clearly delineated the involved area. A 66-yr-old man underwent chest screening examinations for asymptomatic smokers and presented a positive sputum cytology for lung cancer. Conventional chest x-ray, tomography of computed radiography, and a CT scan failed to locate the lesion in the lung. Thallium-201 SPECT, however, was successful in depicting the area of the involvement.

Aged↗

PubMed1991

[Cardiac response to exercise before and after coronary artery bypass grafting: evaluation by continuous ventricular function monitor].

Cardiac response to exercise was evaluated with continuous ventricular function monitor (VEST) with cadmium telluride detector. Thirty-nine patients (30 male and 9 female, aged 57 +/- 8, 23 had old myocardial infarction) were monitored with VEST during and after supine ergometer exercise before and 4 weeks after coronary artery bypass grafting (CABG). Left ventricular ejection fraction (EF) responses were classified into 4 types; type A showed EF increase greater than 5% till end of exercise, type B demonstrated initial increase followed by decrease in EF, type C revealed no significant EF change, type D showed continuous EF decrease. Before CABG, each EF response type A, B, C, and D consisted of 4, 2, 12, 21 patients respectively and after CABG each type included 18, 10, 9, 2. The EF change from rest to peak exercise (delta EF-Ex) improved from -6.4 +/- 8.8% to 5.0 +/- 7.4% (p less than 0.001) after CABG. All patients showed rapid EF increase after exercise or "EF overshoot" (EF-OS). After CABG, the EF change from rest to EF-OS (delta EF-OS) and time to EF-OS (T-OS) were improved from 9.9 +/- 5.2% to 14.9 +/- 5.3% (p less than 0.001) and 162 +/- 86 sec to 80 +/- 48 sec (p less than 0.001) respectively. Type A, B patients showed higher delta EF-OS and shorter T-OS than type C, D patients, suggesting EF overshoot was contingent upon cardiac function during exercise. After CABG, in patients with myocardial infarction, T-OS shortened but delta EF-OS showed less improvement than patients without infarction, suggesting loss of myocardium hampered EF-OS.

Aged↗

PubMed1991

[Assessment of myocardial viability by 24-hour imaging after stress thallium-201 scintigraphy].

Twenty-four-hour delayed imaging after stress thallium-201 scintigraphy was assessed for more accurate detection of viable myocardium. Thirty-two patients with coronary artery disease who showed fixed perfusion abnormality (FPA) at 3 hr imaging after stress Tl study were evaluated with 24 hr delayed imaging. Of 37 areas with FPA, 19 areas (51%) showed redistribution (RD) at 24 hr imaging. After successful coronary artery bypass grafting (n = 19) or transluminal coronary angioplasty (n = 3), stress Tl scintigraphy was performed. Of 13 areas with RD at 24 hr imaging, 12 revealed improvement of Tl uptake after revascularization. On the other hand, of 12 areas with FPA until 24 hr, 8 showed no improvement. In conclusion, conventional stress Tl-201 scintigraphy underestimates myocardial viability, and additional 24 hr imaging permits more accurate assessment of myocardial viability.

Adult↗

PubMed1991

[Clinical application of Tc-99m HMPAO labeled leukocyte imaging in inflammatory disease].

A radionuclide imaging with Tc-99m HMPAO labeled leukocyte was performed in order to determine its clinical usefulness in inflammatory disease. The mixed leukocyte isolated from 40 ml of whole blood containing 5 ml of acid citrate dextrose A and 7 ml of 6% hydroxyethyl starch was incubated with 370 MBq (10 mCi) of Tc-99m HMPAO at 37 degrees C for 30 minutes. Because the labeling efficiency of Tc-99m HMPAO labeled leukocyte was 60.2 +/- 6.3%, the procedure of washing Tc-99m, leukocyte with 5 ml of physiological saline was necessary before intravenous injection, in order to remove the unlabeled Tc-99m HMPAO. The recoveries of Tc-99m leukocyte in the blood after intravenous injection were 41.1 +/- 6.7% at 5 minutes, 33.4 +/- 2.1% at 30 minutes, and 27.2 +/- 3.4% at 2 hours after injection. Moreover, the labeled leukocyte was not stained with trypan blue. Therefore, the biological activity of the Tc-99m leukocyte was maintained as that of In-111 oxine labeled leukocyte. In the 39 patients with clinical suspicion of inflammatory disease including 15 patients with acute and chronic infectious disease where both Tc-99m leukocyte and Ga-67 citrate imagings were performed, the sensitivity, specificity and accuracy for infectious disease were 47%, 100% and 79% with Tc-99m leukocyte, and 67%, 79% and 74% with Ga-67 citrate. These results suggest that Tc-99m HMPAO labeled leukocyte imaging is promising for evaluating inflammatory disease because of the much higher specificity, the ready availability of Tc-99m HMPAO, the good image quality, and the lower radiation dose to the patient.

Gallium Radioisotopes↗

PubMed1991

[Basic evaluation of an ambulatory ventricular function monitor with a a cadmium telluride detector].

The reliability of a new ambulatory ventricular function monitor (VEST) with cadmium telluride (Cd-Te) detector was validated. No counting loss was observed under 20 kcps. In phantom study, more than 200 ml with 6 cm distance from the detector and more than 300 ml with 6-12 cm distance, underestimation of volume was observed. Ejection fraction (EF) calculated in phantom study showed close value to the true EF in 50-400 ml of end-diastolic volume. In 10 patients, 1-2 cm detector shift toward right upper, upper and left showed underestimation of EF. Good correlation of gamma camera EF (X) and VEST EF (Y) was obtained (Y = 0.96X + 3.6(%), n = 37, r = 0.93, p less than 0.001). EF change from rest values, obtained from each comparable exercise and post exercise stage by gamma camera (X) and VEST (Y), showed good correlation (Y = 0.95X + 0.8, n = 20, r = 0.85, p less than 0.001). In conclusion Cd-Te VEST was considered as a reliable EF measurement technique similar to gamma camera.

Cadmium↗

PubMed1991

[The diagnostic value of In-111 transferrin imaging in protein-losing gastroenteropathy].

The diagnostic value of In-111 transferrin abdominal imaging was studied in 17 patients with clinical suspicion of protein-losing gastroenteropathy, compared to that of alpha-1-antitrypsin fecal clearance test. The presence or absence of gastrointestinal protein-loss was finally decided based on the result of alpha-1-antitrypsin fecal clearance test (normal range, less than 13 ml/day) or of protein content measurement on the gastric juice (normal range, less than 71 mg/dl). In-111 transferrin was labeled in vitro. After intravenous administration, serial anterior abdominal images were obtained. All seven patients with a value equal to or more than 20 ml/day on the alpha-1-antitrypsin clearance test and two out of ten patients with a value less than 20 ml/day showed definite intestinal activity demonstrating protein-loss, and the loss-site was estimated by observing the movement of radiotracer within the bowel lumen. The patients with severe protein-loss showed the intestinal activity on the early image. In the patients with milder protein-loss, on the other hand, the activity was noted on the later image. All two patients with positive In-111 transferrin imaging and negative alpha-1-antitrypsin test were associated with protein-losing gastropathy, where a value of alpha-1-antitrypsin clearance was not increased because of denatured alpha-1-antitrypsin by acidic gastric juice and pepsin. These results suggest that In-111 transferrin abdominal imaging can be more useful for the diagnosis of protein-losing gastroenteropathy, because of its capabilities to evaluate the patients with gastropathy as well as to estimate the loss-site.

Adult↗

PubMed1990

Mechanism of gallium 67 accumulation in inflammatory tissue.

The present study was undertaken to elucidate the accumulation mechanism of gallium 67 in inflammatory tissue. 67Ga accumulation in inflammatory tissue was observed by macro- and microautoradiogram. Permeability indices were calculated for serum albumin from blood vessels into inflammatory and normal tissue. Neutrophils and macrophages did not play a major role in 67Ga accumulation in the inflammatory tissue because 67Ga could hardly be detected in the sites in which neutrophils were crowded; the accumulation was concentrated in the intercellular space around these cells in the tissue. Permeability indices for inflammatory tissue were much greater than those for normal tissues. It is thought from the present study and previously reported results that 67Ga, together with plasma from permeable blood vessels, readily penetrates the inflammatory tissue and stays there by binding to the acid mucopolysaccharide present in the tissue.

Animals↗

PubMed1990

Error of uptake in dual energy acquisition with 201Tl and 123I labeled radiopharmaceuticals.

In myocardial scintigraphy, simultaneous injection of two radionuclides and dual energy acquisition are potentially useful in the assessment of regional perfusion and metabolism. The feasibility of dual radionuclide study with 201Tl and 123I labeled radiopharmaceuticals (meta-iodobenzylguanidine I 123, in this study) was investigated in phantoms and patients. The crosstalk of one radionuclide to the other pulse height window was defined as the ratio of the 201Tl count in the 123I and 201Tl windows, R[I/Tl], and the ratio of the 123I count in the 201Tl and 123I windows, R[Tl/I]. The ratios were determined in planar images and SPECT studies. In clinical studies with whole body scintigraphy (n = 8), the value of R differed significantly in various organs. In the SPECT study (n = 13), R was not uniform and varied with time and location, resulting in significant errors in uptake and regional count ratio. Thus, dual energy acquisition with 201Tl and 123I labeled radiopharmaceuticals is generally not recommended because of varying amounts of crosstalk interference. Possible solutions to this problem are discussed. The feasibility of dual radionuclide study must be confirmed in human as well as in phantom studies.

3-Iodobenzylguanidine↗

PubMed1990

Diagnostic values of gallbladder hyperperfusion and the rim sign in radionuclide angiography and hepatobiliary imaging.

The diagnostic values of hyperperfusion to the gallbladder fossa and the rim sign were retrospectively evaluated in 24 histopathologically proven cases of gallbladder disease. Although 12 of 13 patients (92%) with acute cholecystitis had nonvisualization of the gallbladder, the positive predictive value with this finding was 71%. However, when the finding was associated with hyperperfusion to the gallbladder fossa or the rim sign, the positive predictive value with both (90%) was markedly increased, compared to the prevalence ratio of 54%. Such a combination could be useful for preserving a high positive predictive value in the diagnosis of acute cholecystitis.

Acute Disease↗

PubMed1990

Tc-99m MDP bone imaging in inflammatory enthesopathy.

A case is presented in which uptake of Tc-99m MDP was noted at the sites of tendon and ligament attachments to the calcaneus in inflammatory enthesopathy. Following successful treatment with corticosteroids, the uptake was markedly decreased in accordance with subsidence of clinical manifestations and normalization of laboratory data. Radionuclide bone imaging may be useful in evaluating the response to treatment with corticosteroids as well as revealing the active disease sites in inflammatory enthesopathy.

Bone and Bones↗

PubMed1990

Shunt between right subclavian vein and the left heart in superior vena cava obstruction due to lung cancer.

A case in which there was a shunt between systemic veins and the left heart in superior vena cava syndrome due to lung cancer is reported. Superior vena cava syndrome developed one and a half years after right upper lobectomy with combined resection of thoracic wall. Radionuclide venography from the right antecubital vein showed immediate visualization of the left ventricle and aorta, before the right atrium and right ventricle were seen. In the superior vena cava syndrome due to a malignant tumor, this rare pathway as well as usual collaterals should be considered.

Carcinoma, Squamous Cell↗

PubMed1990

Thallium-201 accumulation in cerebral candidiasis: unexpected finding on SPECT.

The authors present an unexpected finding of Tl-201 uptake in the intracerebral lesions due to candidiasis. SPECT demonstrated the extent of the lesions and a high target-to-background ratio. The regions where abnormal Tl-201 accumulation was seen were nearly consistent with CT scans of those enhanced by a contrast agent. After treatment, most of the abnormal Tl-201 accumulation disappeared.

Adult↗

PubMed1990

Tc-99m HMPAO brain perfusion tomography atlas using a high resolution SPECT system.

Excellent SPECT images of brain perfusion with Tc-99m HMPAO were obtained by the use of a three-head rotating gamma camera SPECT system with high resolution (FWHM 7mm) in a normal volunteer. These images should be clinically effective for evaluating various neurologic disorders. Transverse, coronal, and sagittal sectional HMPAO-SPECT images are correlated with corresponding brain MRI images of the same normal volunteer in this atlas.

Adult↗

PubMed1990

Cardiac sarcoidosis demonstrated by Tl-201 and Ga-67 SPECT imaging.

Ga-67 and Tl-201 SPECT was performed to evaluate cardiac sarcoidosis in a 15-year-old boy. Tl-201 SPECT imaging showed decreased uptake in the inferior to lateral wall and Ga-67 accumulation in the area of decreased Tl-201 uptake. These findings suggested cardiac sarcoidosis, and cardiac biopsy confirmed this diagnosis. After corticosteroid therapy, myocardial uptake of Ga-67 disappeared and myocardial TI-201 uptake became more homogeneous.

Adolescent↗

PubMed1990

Evaluation of inferior mesenteric vein blood flow circulation with per-rectal administration of thallium-201 and technetium-99m pertechnetate.

We administered both per-rectal thallium-201 (201Tl) and technetium-99m pertechnetate (99mTc) to patients with liver diseases in order to understand the abnormalities of inferior mesenteric vein (IMV) blood flow circulation. As 201Tl heart-to-liver uptake ratio (H:L), reflecting the degree of portal-systemic shuntings (PSS), increased, the visualization of IMV in general became poor on 99mTc scintigrams. 201Tl H:L in the group with no visualization of IMV on 99mTc scintigrams was significantly higher than in the group with clear visualization of IMV (p less than 0.001). However, there were patients who showed IMV visualization among those with high 201Tl H:L. In these patients, it was considered that IMV blood flowed in the normograde direction, escaping mainly through PSS at the upper part of the portal system, and resulting in elevated H:L. In the patients without IMV visualization, IMV blood flowed in the retrograde direction, escaping mainly through collaterals at the lower part of IMV. Inferior vena cava (IVC) was visualized on 99mTc scintigrams in some patients without IMV visualization, indicating the presence of collaterals from the distal part of IMV to IVC. Per-rectal studies using these two radiotracers can afford us useful informations on the abnormalities of IMV blood flow hemodynamics in patients with liver diseases.

Adult↗

PubMed1990

[201T1 single photon emission computed tomography in the diagnosis of lung cancer].

201T1 SPECT was performed in 84 patients with suspected lung cancer. Both early and delayed scans demonstrated abnormal accumulation in 67 of 68 malignant pulmonary lesions and in nine of 18 benign conditions. All of 64 lung cancer were clearly visualized. Delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) and retention index (degree of retention in the lesion) were helpful to differentiate malignant from benign lesions. This method was also useful to evaluate mediastinal involvement from lung cancer.

Adenocarcinoma↗

PubMed1989

Scintigraphic demonstration of intracranial communication between arachnoid cyst and associated subdural hematoma.

An arachnoid cyst found to have a communication to an associated subdural hematoma was demonstrated with the Tc-99m DTPA brain scintigraphy. Although arachnoid cysts are known to be silent, when a patient with an arachnoid cyst develops signs of increased intracranial pressure or neurological deficits, the presence of a complication, including subdural hematoma, intracystic hemorrhage or subdural hygroma, is highly suspected. In the present case, the patient with an arachnoid cyst had a subdural hematoma following minor head injury. Tc-99m DTPA brain scintigraphy showed abnormal accumulation of the tracer not only in the hematoma but in the arachnoid cyst. This observation suggested communication of the two lesions, which was confirmed at surgery.

Adolescent↗