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N Tonami

Publications and source records attributed to N Tonami.

At least 109 records · Page 6Linked to original sources
PubMed1997

Thallium-201 SPECT in differentiating bone infarction from metastatic lesions in osteosarcoma.

The authors present a case of bone infarction in the proximal epiphysis of the right tibia, which was caused by preoperative intraarterial chemotherapy for osteosarcoma. MR imaging revealed that suspected metastases had inhomogeneous signal intensity similar to that of the primary tumor, which made a metastatic lesion difficult to exclude. On TI-201 SPECT, no accumulation was found in the lesions, confirming that they were not osseous metastases. Consequently, this enabled limb salvage surgery to be performed with joint preservation. Intraoperative biopsy revealed no viable tumor cells in the lesion, and bone infarction was suspected. TI-201 SPECT was very useful, not only in differentiating bone infarction from tumor progression, including metastatic lesions, but also in the determination of the operative technique.

Adolescent↗
PubMed1997

Thyroid nodules: evaluation with US-guided core biopsy with an automated biopsy gun.

To evaluate the efficacy of ultrasound (US)-guided automated core biopsy of thyroid nodules, 74 biopsies were performed in 61 consecutive patients with an 18-gauge short-throw (1.1-cm excursion) biopsy gun. Results were correlated with diagnoses made at surgery (n = 38) or at sonographic follow-up of at least 6 months (n = 36). Sensitivity, specificity, and accuracy of diagnoses made with automated core biopsy were 84%, 95%, and 91%, respectively. US-guided biopsy with an automated biopsy gun allowed accurate assessment of thyroid nodules.

Adult↗
PubMed1997

[Evaluation of the graft flow reserve after coronary artery bypass grafting by stress 201T1 myocardial SPECT: comparison between arterial grafts and venous grafts].

We performed stress 201T1 myocardial SPECT to evaluate ischemia and perfusion reserve after coronary artery bypass grafting (CABG). A total of 103 patients was performed stress 201T1 myocardial SPECT one month after CABG. Each patient's myocardium was divided into 9 segments and visually evaluated using five grade scoring system (0 = defect, 1 = severe decrease, 2 = moderate decrease, 3 = mild decrease, 4 = normal uptake). Eleven of 133 (8.27%) segments covered by patent venous grafts showed reversible 201T1 defect, however, 36 of 117 (30.8%) segments which covered by patent arterial grafts showed reversible 201T1 defect. This finding was observed more significantly in arterial grafts than in venous grafts (p < 0.001). These finding suggests that arterial grafts have lower flow capacity than venous grafts at peak exercise.

Aged↗
PubMed1997

[Brain uptake ratio as an index of cerebral blood flow obtained with 99mTc-ECD].

A new index of cerebral blood flow (brain uptake ratio, BUR) using 99mTc-ECD was developed and evaluated in 66 patients (132 cerebral hemispheres). BUR was calculated from brain count in anterior planar image (60-80 sec after injection of 99mTc-ECD) divided by the summation of the count of aortic arch during first transit of radionuclide. BUR correlated well with brain perfusion index (BPI) obtained with Patlak plot method (r = 0.960, p < 0.001). In conclusion, BUR is useful as a simple and non-invasive index reflecting cerebral blood flow.

Adolescent↗
PubMed1997

[Evaluation of bone and soft tissue lesion using 99mTc-MIBI: comparison with 201Tl and the relation to chemotherapeutic effect].

Thirty-five patients with bone and soft tissue lesions were studied with 99mTc-MIBI and 201Tl to compare the uptake of two tracers. Planar images were obtained 15 min (early image) and 3 hr (delayed image) after the injection of both tracers. Images were evaluated visually and quantitatively using uptake ratio (lesion/background). In visual analysis, 23 of 35 patients showed similar uptake of both tracers, 9 showed more intense uptake of 99mTc-MIBI than 201Tl, and 3 showed more intense uptake of 201Tl than 99mTc-MIBI on early images. On delayed images, 21 of 32 patients showed similar uptake of both tracers, 3 showed more intense uptake of 99mTc-MIBI than 201Tl, and 8 showed more intense uptake of 201Tl than 99mTc-MIBI. In quantitative analysis, similar 201Tl and 99mTc-MIBI uptake ratios were obtained on early images. On delayed images, 99mTc-MIBI uptake ratios are less than that of 201Tl, but the difference was not significant. In some cases, 99mTc-MIBI accumulation was washed out on delayed images, therefore the early image is essential to evaluate 99mTc-MIBI accumulation. In all cases with the uptake ratios less than 1.20 on delayed 99mTc-MIBI images, chemotherapy was not effective. In malignant tumors, decreased uptake of 99mTc-MIBI accumulation on delayed images may indicate that chemotherapy is not effective. Delayed 99mTc-MIBI image may be a potential marker predicting chemotherapeutic effect in malignant bone and soft tissue tumors.

Adolescent↗
PubMed1997

Evaluating benign and malignant bone and soft-tissue lesions with technetium-99m-MIBI scintigraphy.

UNLABELLED: This study compares the ability of 201TI and 99mTc-MIBI to detect and assess tumor response to chemotherapy in malignant and benign bone and soft-tissue lesions. METHODS: Forty-two patients with various bone and soft-tissue pathologies (29 malignant and 13 benign lesions) were studied with 201TI and 99mTc-MIBI. Planar 201TI scintigraphy was performed 15 min after injection of 111 MBq of 201TI. Within 1 wk of the 201TI study, radionuclide angiography with 600-740 MBq of 99mTc-MIBI was performed and planar imaging was done 15 min later. RESULTS: In visual analysis, 31 of 42 patients showed similar uptake of both tracers, 8 showed more intense uptake of 99mTc-MIBI than 201TI and 3 showed more intense uptake of 201TI than 99mTc-MIBI. In quantitative analysis, similar 201TI and 99mTc-MIBI uptake ratios were obtained (1.96 +/- 1.25 versus 1.96 +/- 1.02, respectively; p = ns). The perfusion index derived from 99mTc-MIBI radionuclide angiography was higher than 99mTc-MIBI uptake ratio (2.33 +/- 1.23 versus 1.96 +/- 1.02, respectively; p < 0.005), but correlated well with 99mTc-MIBI uptake ratio (r = 0.75). In 11 patients with malignant tumors, 201TI and 99mTc-MIBI scintigraphy was repeated after chemotherapy and the uptake of both tracers was significantly suppressed in patients with complete response confirmed by histological evaluation. In patients with complete response (n = 3), the uptake ratio of both tracers was reduced by more than 50%, whereas, less than 20% reduction of uptake ratio was observed in patients with nonresponse (n = 6). CONCLUSION: The ability of 99mTc-MIBI to detect malignant and benign bone and soft-tissue lesions and to assess tumor response to chemotherapy was comparable to that of 201TI. In addition, blood flow could be assessed by radionuclide angiography with 99mTc-MIBI. Technetium-99m-MIBI is a promising radiopharmaceutical for the evaluation of bone and soft-tissue lesions.

Abscess↗
PubMed1997

Significance of late redistribution thallium-201 imaging after rest injection for detection of viable myocardium.

UNLABELLED: The aim of this study was to determine whether late redistribution imaging after rest injection of 201Tl would provide further information on myocardial viability over conventional rest-early redistribution 201Tl imaging. METHODS: Twenty-nine patients with coronary artery disease and left ventricular dysfunction underwent rest, early (3-4 hr) and late (20-24 hr) redistribution 201Tl and gated blood pool studies. In 14 patients with successful revascularization, gated blood pool study was repeated after the coronary intervention. RESULTS: Nine of 29 patients showed early redistribution, and six additional patients showed further redistribution on the late images. Of 136 segments with initial 201Tl defects, 18 showed early redistribution, and 10 showed late redistribution. When a threshold of 60% of peak activity was used as an index of myocardial viability, only a small fraction (3%) of the initial 201Tl defects were additionally considered viable by the late images. In 14 patients who underwent revascularization, the positive (69%) and negative (87%) predictive values of the early redistribution images for functional recovery were similar to those obtained by the late images (68% and 86%, respectively). CONCLUSION: Although late redistribution after rest injection of 201Tl occasionally occurs, most of the clinically relevant information on myocardial viability may be obtained by conventional rest-early redistribution 201Tl imaging when the defect severity is considered an index of tissue viability.

Aged↗
PubMed1997

Brain perfusion SPECT in Lyme neuroborreliosis.

SPECT imaging brain perfusion using 99mTc-HMPAO was performed on a 38-yr-old women with Lyme neuroborreliosis confirmed by autopsy. The patient had been suspected of spinocerebellar degeneration. Cerebral blood flow was diffusely decreased throughout cerebral cortices but cerebellar blood flow was not impaired, which indicated that the diagnosis was unlikely spinocerebellar degeneration. These findings suggested that brain perfusion SPECT provides useful information in diagnosing the patients with Lyme neuroborreliosis, especially when spinocerebellar degeneration is included in the differential diagnosis.

Adult↗
PubMed1997

[Evaluation of clinical utility of 111In-DTPA-IgG scintigraphy in the detection of inflammation/infection--a report of multicenter phase III clinical trials].

This is the report of phase III study to evaluate the safety and utility of 111In-DTPA-IgG in patients with strongly suspected inflammation/infection. One hundred and forty five patients with suspected sites of inflammation/infection were enrolled in the study. Only a few adverse experiences in one patient were reported, which were interpreted as having a possible relationship to the agent. A total of 171 suspected sites (12 in head and neck, 39 in thorax, 44 in abdomen and pelvis, 62 in musculoskeletal system, and 14 in other regions) were evaluated by investigators at each institute. Out of 171 sites, 18 were determined to be unevaluable, and 12 false negative and 5 false positive cases were observed. Overall sensitivity and specificity was 89.8% and 85.7%, respectively, and the agent proved to be effective in detecting lesions anywhere throughout the body. The analysis of data from this Phase III study indicates that 111In-DTPA-IgG is well-tolerated in patients and effective in determining focal sites of inflammation/infection although the physiological accumulation in some tissues such as the sinus or liver and possible excretion into the gastrointestinal tract may make it difficult to localize lesions.

Aged↗
PubMed1997

[Evaluation of ischemic heart disease using the index of relative 99mTc-tetrofosmin uptake increase at exercise].

We calculated an increase of myocardial 99mTc-tetrofosmin uptake during exercise from resting condition, which was thought to reflect coronary flow reserve, and assessed whether this method enhanced the detection of coronary artery disease (CAD). Exercise myocardial SPECT was performed using 99mTc-tetrofosmin with one-day method (exercise-rest) in 26 patients. Twenty-one patients were suspected to have ischemic heart disease and 5 were control patients. A polar map was used to evaluate the increase in counts after exercise. The parameter of % uptake increase was obtained by the ratio of exercise and resting myocardial counts. The uptake was corrected for administration dose and time decay between the exercise and rest studies. The sensitivity for detecting patients with significant coronary stenosis by visual evaluation and % uptake increase map was 60% and 90%, respectively. In 5 patients, % uptake increase map detected stenosed coronary artery lesions that could not be detected by visual analysis. We concluded that the % uptake increase map combined with conventional SPECT images enhanced the detectability of coronary artery disease and the evaluation of the degree of coronary flow reserve.

Adult↗
PubMed1997

Assessment of improvement of myocardial fatty acid uptake and function after revascularization using iodine-123-BMIPP.

UNLABELLED: We used beta-methyl iodophenyl pentadecanoic acid (BMIPP) to evaluate changes in myocardial fatty acid utilization before and after revascularization and the ability of BMIPP to predict functional recovery in patients with chronic coronary artery disease. METHODS: Thirty-four patients with chronic coronary artery disease (60 +/- 10 yr) underwent BMIPP and 201Tl SPECT (stress-reinjection 201Tl in 29 patients and resting 201Tl in 5 patients) before and 2-5 wk after percutaneous transluminal angioplasty (n = 23) or coronary artery bypass surgery (n = 11). Cardiac function was evaluated by gated blood-pool scintigraphy (n = 26) or two-dimensional echocardiography (n = 8) before and after revascularization. RESULTS: In 32 patients with reduced BMIPP uptake before revascularization, scintigraphic findings with 201Tl improved in 28 patients after revascularization. In these 28 patients, BMIPP uptake improved in 20 patients (71%). Wall motion abnormality was observed in 16 of these 20 patients before revascularization, with 15 showing wall motion improvement after revascularization. In eight patients without improvement of BMIPP uptake, despite 201Tl uptake improvement, wall motion abnormality was observed in four patients before revascularization; after revascularization, one showed wall motion recovery, and three did not. Ejection fraction (EF) improvement after revascularization correlated best with the area of improved BMIPP uptake (r = 0.84, p < 0.0005). EF improvement also correlated with the area of improved reinjection 201Tl uptake (r = 0.54, p < 0.05) and improved 201Tl uptake at stress after revascularization (r = 0.48, p < 0.05). The area of discordant uptake of BMIPP less than reinjection 201Tl uptake before revascularization was a good predictor of EF improvement after revascularization (r = 0.58, p < 0.01); however, the area of reversible 201Tl defect was not (r = 0.34, p = 0.15). CONCLUSION: In patients with chronic coronary artery disease, functional improvement after revascularization is closely related to the recovery of BMIPP uptake. Discordant BMIPP uptake less than reinjection 201Tl uptake is a potential predictor of functional recovery.

Angioplasty, Balloon, Coronary↗
PubMed1997

[Dual isotope SPECT with 99mTc and 123I using four-energy-window (FEW) method].

We devised "four-energy-window" (FEW) method which permits simultaneous acquisition for dual isotope single photon emission tomography (SPECT) studies using 99mTc and 123I of which photopeak is in close vicinity to each other. This acquisition method requires a total of four energy windows: two main windows for 99mTc (126-143 keV) and 123I (156-175 keV), respectively, and two 5% sub-windows which are set below the 99mTc window and above the 123I window, respectively. Two virtual windows (5%) are additionally set above the 99mTc and below the 123I window, respectively, to apply the triple-energy-window (TEW) method for the scatter correction. A phantom study demonstrated that photocounts from the two radionuclides could be completely separated from each other and that SPECT images obtained had preferable property for quantitative analysis. This method was applied to clinical, dual-radionuclide myocardial studies using 99mTc-MIBI and 123I-BMIPP, and was found to provide excellent images each tracer.

3-Iodobenzylguanidine↗