Shigeru Kosuda

Gated single-photon emission tomography imaging protocol to evaluate myocardial stunning after exercise

Abstract. This study was designed to apply ECG-gating to stress myocardial perfusion single-photon emission tomography (SPET) for the evaluation of myocardial stunning after exercise. Technetium-99m sestamibi was selected as the perfusion agent and a rest/exercise 1-day protocol was employed. Fourteen patients without coronary stenosis and 33 patients with coronary stenosis were enrolled in the study. We carried out three data acquisitions with ECG-gating: a 15-min data acquisition starting 30 min after the rest injection (AC1), a 5-min acquisition starting 5 min after the stress injection (AC2) and a 15-min acquisition starting 20 min after the stress injection (AC3). Calculation of left ventricular ejection fraction (LVEF) values was performed by means of automatic determination of the endocardial surface for all gating intervals in the cardiac cycle. Measured global EF values in 14 patients without coronary stenosis were 52.3%±7.6% (AC1), 60.6%±8.9% (AC2) and 55.6%± 5.6% (AC3), and those in 11 patients with severe ischaemia were 53.6%±8.0% (AC1), 45.6%±12.1% (AC2) and 49.7%±10.7%. The magnitude of the depression of post-stress LVEF relative to the rest LVEF correlated with the severity of ischaemia (r=0.594, P=0.002), and segments manifesting post-stress functional depression were associated with ischaemic segments showing reversible perfusion defects. Stress myocardial perfusion SPET with ECG-gating is a feasible method for the evaluation of myocardial stunning as well as exercise-induced ischaemia.

Diffusion kurtosis imaging study of prostate cancer: Preliminary findings

To evaluate the differences in parameters of diffusion kurtosis imaging (DKI) between prostate cancer, benign prostatic hyperplasia (BPH), and benign peripheral zone (PZ).

Honda sign and variants in patients suspected of having a sacral insufficiency fracture.

Purpose: The purpose of this study was to reassess whether the Honda sign (HS) and its variants on bone scans can be used to differentiate an insufficiency fracture (IF) of the sacrum from a metastasis and to evaluate extrapelvic tracer accumulation in patients suspected of having a sacral IF. Methods and Materials: We retrospectively reviewed 34 bone scans of 26 patients suspected of having a sacral IF between January 1998 and June 2003. Results: Twenty-four of the patients had a sacral IF and 1 had a sacral metastasis from prostate cancer and another from lung cancer. The bone scans of only 15 (63%) of the 24 patients with a sacral IF exhibited the HS, 8 (33%) scans exhibited variants, and 4 (4%) scans showed whole-sacrum uptake. One of the 2 patients with metastasis exhibited the HS and the other exhibited a variant. The sensitivity and positive predictive value of HS plus its variants as diagnostic criteria for sacral IF were 96% and 92%, respectively. Seventeen patients (71%) had extrasacral accumulation. The most common site was the pubic bone (50%, 12 of 24), and the second most common site was the spine (46%, 11 of 24), where the accumulation was the result of a compression fracture or degenerative joint disease of the spine. Conclusions: A “Honda sign or variation” with evidence of fractures elsewhere or no evidence of other metastatic disease should be strong evidence for a sacral insufficiency fracture. The likelihood of having a solitary metastasis to the sacrum is small.

Reassessment of quantitative thallium-201 brain SPECT for miscellaneous brain tumors.

In order to reassess the value of quantitative thallium-201 brain SPECT in the differentiation of miscellaneous brain tumors, we studied a total of 89 patients—35 pre-operative patients suspected of having a brain tumor and 54 post-operative patients with a brain tumor. We came to the conclusion that quantitative Tl-201 brain SPECT was very useful in discriminating cerebral radiation necrosis from recurrent tumor, estimating residual tumor burden, and detecting tumor regrowth earlier in postoperative patients. In preoperative patients, however, Tl-201 SPECT cannot be used effectively to differentiate glioma from other intracranial tumors, although intense uptake of Tl-201 may provide evidence of glioblastoma or a hypervascular lesion.

Technetium-99m tetrofosmin and technetium-99m sestamibi imaging of multiple metastases from differentiated thyroid carcinoma

A 79-year-old male with follicular thyroid carcinoma metastasizing to the lung, bone and lymph nodes was subjected to whole-body scintigraphy using technetium-99m tetrofosmin and99mTc-sestamibi. Both agents delineated the metastatic lesions and the two image qualities were comparable. We believe that99mTc-tetrofosmin and99mTc-sestamibi images may be helpful in localizing metastatic foci and substitute for thallium-201 in the follow-up of patients with differentiated thyroid carcinoma.

Prediction of survival in patients with suspected recurrent cerebral tumors by quantitative thallium-201 single photon emission computed tomography

PURPOSE To assess whether quantitative 201Tl single photon emission computed tomography (SPECT) can be used as a prognostic test in patients with suspected recurrent cerebral tumor, regardless of various combined therapies given. METHODS AND MATERIALS The study population consisted of 22 patients with grade 4, 3, or 2 glioma and 7 patients with solitary cerebral metastasis. All patients had undergone combined radiotherapy and chemotherapy after or during surgical debulking. Each patient underwent 201Tl brain SPECT to differentiate recurrent tumor from cerebral radiation necrosis, because the prior computed tomography and/or magnetic resonance imaging showed a mass lesion with an irregularly enhanced rim in the irradiation field. RESULTS Higher values of 201Tl index (L/N ratio) showed a tendency for shorter survival (r = -0.502, p < 0.05). In patients with grade 3 glioma or solitary cerebral metastasis, survival time was definitely dependent upon 201Tl index values, that is, above or below the baseline index of 2.5. Grade 4 glioma patients, however, had a very short-term survival independent of 201Tl index values. CONCLUSION Quantitative 201Tl SPECT may be a useful tool for predicting survival of patients with suspected recurrent cerebral tumor and may be used in place of fluorine-18-2-deoxy-2-fluoro-D-glucose (18F-FDG) scan.

Decision-tree sensitivity analysis for cost-effectiveness of whole-body FDG PET in the management of patients with non-small-cell lung carcinoma in Japan

BackgroundWhole-body 2-fluoro-2-d-[18F]deoxyglucose [FDG] positron emission tomography (WB-PET) may be more cost-effective than chest PET because WB-PET does not require conventional imaging (CI) for extrathoracic staging.Methods: The cost-effectiveness of WB-PET for the management of Japanese patients with non-small-cell lung carcinoma (NSCLC) was assessed. Decision-tree sensitivity analysis was designed, based on the two competing strategies of WB-PET vs. CI. WB-PET was assumed to have a sensitivity and specificity for detecting metastases, of 90% to 100% and CI of 80% to 90%. The prevalences of M1 disease were 34% and 20%. One thousand patients suspected of having NSCLC were simulated in each strategy. We surveyed the relevant literature for the choice of variables. Expected cost saving (CS) and expected life expectancy (LE) for NSCLC patients were calculated.Results: The WB-PET strategy yielded an expected CS of

Change in regional pulmonary perfusion as a result of posture and lung volume assessed using technetium-99m macroaggregated albumin SPET

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How should tracers be injected to detect for sentinel nodes in gastric cancer--submucosally from inside or subserosally from outside of the stomach?

1,493US per patient and an expected LE of minus 0.0246 years to minus 0.0136 years per patient for the 71.4% NSCLC and 34% M1 disease prevalence at our hospital. PET avoided unnecessary bronchoscopies and thoracotomies for incurable and benign diseases. Overall, the CS for each patient was

18F-FDG-PET/CT as an indicator for resection of pulmonary epithelioid hemangioendothelioma.

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