No abstract available.
Capsaicin* ; Lymphocytes* ; Lymphoid Tissue*

PURPOSE: We investigated the statistical methods to compose the functional brain map of human working memory and the principal factors that have an effect on the methods for localization. MATERIALS AND METHODS: Repeated PET scans with successive four tasks, which consist of one control and three different activation tasks, were performed on six right-handed normal volunteers for 2 minutes after bolus injections of 925 MBq H0 at the intervals of 30 minutes. Irnage data were analyzed using SPM96 (Statistical Parametric Mapping) imple-mented with Matlab (Mathworks Inc., U.S.A.). Images from the same subject were spatially registered and were normalized using linear and nonlinear transformation methods. Significant difference between control and each activation state was estimated at every voxel based on the general linear model. Differences of global counts were removed using analysis of covariance (ANCOVA) with global activity as covariate. Using the mean and variance for each condition which was adjusted using ANCOVA, t-statistics was performed on every voxel To interpret the results more easily, t-values were transformed to the standard (saussian distri-bution (Z-score). RESULTS: All the subjects carried out the activation and control tests successfully. Average rate of correct answers was 95%. The numbers of activated blobs were 4 for verbal memory I, 9 for verbal memory II, 9 for visual memory, and 6 for canjunctive activation of these three tasks. The verbal working memory activates predominantly left-sided slruetures, and the visual memory activates the right hernisphere. CONCLUSION: We conclude that rCBF PET imaging and statistical parametric mapping method were useful in the localization of the brain regions for verbal and visual working memory.
Brain Mapping* ; Brain* ; Electrons* ; Healthy Volunteers ; Humans ; Linear Models ; Memory ; Memory, Short-Term ; Positron-Emission Tomography*

BACKGROUND AND OBJECTIVES: Dual isotope myocardial SPECT, rest thallium-201/dipyridamole stress Tc-99m sestamibi is used to diagnose coronary artery disease. We examined predictive value of myocardial SPECT for the prognosis of patients having or suspected coronary artery disease. MATERIALS AND METHOD: We examined 692 patients referred for dipyridamole stress myocardial perfusion SPECT. Cardiac events (hard and soft events) were followed up with medical record review and telephone interview. Survival analysis and multivariate Cox proportional hazard model were used to find significant predictors and the incremental predictive value of myocardial SPECT. Patients with coronary angiography (n=246) were analyzed in separate group. RESULTS: There were 4 hard events and 3 soft events in 341 normal SPECT group (1.20%/yr). There were 5 hard events and 21 soft events in 351 abnormal SPECT group (4.69%/yr). Survival curve was separated between normal SPECT group and abnormal SPECT group (p<0.01). In univariate analysis, smoking, history of myocardial infarction, typical chest pain and SPECT findings were important variables. In multivariate analysis, SPECT result was the single most independent predictor. Large reversible perfusion abnormality predicted worse prognosis. In patients with coronary angiography, SPECT did not add statistically significant predictive value to the coronary angiography. CONCLUSION: Dipyridamole stress Tl-201/ MIBI dual isotope myocardial perfusion SPECT provided excellent prognostic information. Extent of reversible perfusion decrease was the independent predictor of future cardiac events.
Chest Pain ; Coronary Angiography ; Coronary Artery Disease ; Dipyridamole ; Humans ; Interviews as Topic ; Medical Records ; Multivariate Analysis ; Myocardial Infarction ; Perfusion ; Prognosis ; Proportional Hazards Models ; Smoke ; Smoking ; Tomography, Emission-Computed, Single-Photon*

No abstract available.
Coronary Artery Disease* ; Coronary Vessels* ; Tomography, Emission-Computed, Single-Photon*

PURPOSE: We investigated reproducibility of the quantification of left ventricular volume and ejection fraction, and grading of myocardial wall motion and systolic thickening when we used gated myocardial SPECT and Cedars quantification software. MATERIALS AND METHODS: We performed gated myocardial SPECT in 33 consecutive patients twice in the same position after Tc-99m-MIBI SPECT. We used 16 frames per cycle for the gatingof sequential Tc-99m-MTBI SPECT. After reconstruction, we used Cedars quantitative gated SPECT and calculated ventricular volume and ejection fraction (EF), Wall motion was graded using 5 point score. Wall thickening was graded using 4 point score. Coefficient of variation for re-examination of volume and fraction were calculated. Kappa values (k-value) for assessing reproducibility of wall motion or wall thickening were calculated. RESULTS: Enddiastolic volumes (EDV) ranged from 58 mi to 248 ml (122 ml +/- 42 ml), endsystolic volumes (ESV) from 20 mi to 174 mi (65 ml +1- 39 ml), and EF from 20% to 68% (51% +/- 14%). Geometric mean of standard deviations of 33 patients was 5.0 ml for EDV, 3.9 ml for ESV and 1.9% for EF. Their average differences were not different from zero (p>0.05). k-value for wall motion using 2 consecutive images was 0.76 (confidence interval: 0.71-0.81). k-value was 0.87 (confidence interval:0.83-0.90) for assessment of wall thickening. CONCLUSION: We concluded that quantification of functional indices, assessment of wall motion and wall thickening using gated Tc-99m-MIBI SPECT was reproducible and we could use this method for the evaluation of short-acting drug effect.
Heart ; Humans ; Tomography, Emission-Computed, Single-Photon*

PURPOSE: We investigated whether myocardial SPECT had additional usefulness to clinical, functional or surgical indices for the preoperative evaluation of cardiac risks in noncardiac surgery. MATERIALS AND METHODS: 118 patients (M: F=66:52, 62.7+/-10.5 years) were studied retrospectively. Eighteen underwent vascular surgeries and 100 nonvascular surgeries. Rest T1-201/stress Tc-99m-MIBI SPECT was performed before operation and cardiac events (hard event: cardiac death and myocardial infarction; soft event: ischemic ECG change, congestive heart failure and unstable angina) were surveyed through perioperative periods (14.6+/-5.6 days). Clinical risk indices, functional capacity, surgery procedures and SPECT findings were tested for their predictive values of perioperative cardiac events. RESULTS: Peri-operative cardiac events occurred in 25 patients (3 hard events and 22 soft events). Clinical risk indices, surgical procedure risks and SPECT findings but functional capacity were predictive of cardiac events. Reversible perfusion decrease was a better predictor than persistent decrease. Multivariate analysis sorted` out surgical procedure risk (p=0.0018) and SPECT findings (p=0.0001) as significant risk factors. SPECT could re-stratify perioperative cardiac risks in patients ranked with surgical procedures. CONCLUSION:: We conclude that myocardial SPECT provides additional predictive value to surgical type risks as well as clinical indexes or functional capacity for the prediction of preoperative cardiac events in noncardiac surgery.
Death ; Electrocardiography ; Heart Failure ; Humans ; Multivariate Analysis ; Myocardial Infarction ; Myocardial Ischemia ; Perfusion ; Perioperative Period ; Retrospective Studies ; Risk Factors ; Tomography, Emission-Computed, Single-Photon*

PURPOSE: For the purpose of using Re-188 as a therapeutic radionuclide, we performed the quality control of the W-188/Re-188 generation system. MATERIALS AND METHODS: Several quality control tests of the Re-188 eluate from generator were carried out of about 300 days. After elution of Re-188 with normal saline (20 ml), chromatogram and gamma-ray spectrum of Re-188 eluate were obtained. The presence of aluminum which was derived from the elumina bed of the generator was detected by using aluminum ion indicator kit. Re-188 eluate was allowed to decay for several days, and then W-188 breakthrough in the Re-188 eluate was measured by detecting gamma-ray at 227 keV and 290 keV. The pH and the pyrogenicity of the eluate were checked. The Re-188 eluate from the generator was 67.4+/-7.0% of W-188 during 270 days, and it was hightest at third day after previous elution. Radiochemical purity of Re-188 eluate obtained from chromatogram was higher than 99%. Gamma-ray spectrum of Re-188 eluate showed a peak at 155 keV. Aluminum ion and W-188 contamination were not detected. The pH of Re-188 eluate was 3 and the concentration yield was 85%. CONCLUSION: Our experiments and results on quality control tests of Re-188 eluate from W-188/Re-188 generator may be useful for setting W-188/Re-188 generator in hospitals.
Aluminum ; Hydrogen-Ion Concentration ; Quality Control*

PURPOSE: For the purpose of using Re-188 as a therapeutic radionuclide, we performed the quality control of the W-188/Re-188 generation system. MATERIALS AND METHODS: Several quality control tests of the Re-188 eluate from generator were carried out of about 300 days. After elution of Re-188 with normal saline (20 ml), chromatogram and gamma-ray spectrum of Re-188 eluate were obtained. The presence of aluminum which was derived from the elumina bed of the generator was detected by using aluminum ion indicator kit. Re-188 eluate was allowed to decay for several days, and then W-188 breakthrough in the Re-188 eluate was measured by detecting gamma-ray at 227 keV and 290 keV. The pH and the pyrogenicity of the eluate were checked. The Re-188 eluate from the generator was 67.4+/-7.0% of W-188 during 270 days, and it was hightest at third day after previous elution. Radiochemical purity of Re-188 eluate obtained from chromatogram was higher than 99%. Gamma-ray spectrum of Re-188 eluate showed a peak at 155 keV. Aluminum ion and W-188 contamination were not detected. The pH of Re-188 eluate was 3 and the concentration yield was 85%. CONCLUSION: Our experiments and results on quality control tests of Re-188 eluate from W-188/Re-188 generator may be useful for setting W-188/Re-188 generator in hospitals.
Aluminum ; Hydrogen-Ion Concentration ; Quality Control*

BACKGROUND: Total occlusion of the infrarenal abdominal aorta is a very rare disease in clinical practice. The clinical outcome may be poor unless management is attempted promptly. Surgical bypass has been recommended as the treatment of choice for these lesions. However, there was relatively high surgical mortality and morbidity associad with aorto-bifemoral bypass graft in patients with other systemic disease, especially coronary artery disease. As a result, the use of, thrombolysis with percutaneous transluminal angioplasty (PTA) has recently been extended to this disease as an alternative method to surgery. PTA is technically simpler with less morbidity and mortality than surgery.We report our experience with thrombolysis and balloon angioplasty of total aortic occlusion in 14 patients between March 1991 and December 1996. METHODS: Fourteen patients, whose mean age was 59+/-13 years (11 male, 3 female), serve as the study's patients. Aortography was introduced via transbrachial artery. The end hole multipurpose catheter with guidewire was introduced into the thrombotic portion of the total occlusion. Urokinase was infused into the thrombus through the catheter if there were no contraindications. in sysremic thrombolysis. Thrombolytic therapy was continued until the thrombi was resolved and flow was restored. Balloon dilatation was followed in residual stenotic lesions. Stents were implanted in case of suboptimal results after ballooning. RESULTS: Clinical findings were resting leg pain in 6 patients, gangrene in 5 patients, and claudication in 3 patients. The causes of aortic occlusion were thromboembolism in 4 patients and thrombosis of an atherosclerotic aorta in 10 patients. Location of obstruction was below the renal artery in all cases. The clinical outcome of interventional therapy was successful in all cases except one patients. Operative treatment was undertaken in 2 cases because they could not received thrombolytic therapy due to contraindication and complication of thrombolytic therapy (gastrointestinal bleeding). Near normal revascularization was achieved in 3 patients by thrombolytic therapy only. PTA was performed at the stenotic after thrombolytic therapy in 4 patients. Stenting were performed at the stenotic sites after balloon dilatation in another 4 patients. There was bleeding complication in one case. CONCLUSIONS: Interventional therapy such as thrombolytic therapy with PTA is an effective and safe treatment modality for abdominal aortic total occlusion in selected cases. These techniques were very useful in some high risk patients who received surgical bypass procedures.
Angioplasty ; Angioplasty, Balloon ; Aorta ; Aorta, Abdominal* ; Aortography ; Arteries ; Catheters ; Coronary Artery Disease ; Dilatation ; Gangrene ; Hemorrhage ; Humans ; Leg ; Male ; Mortality ; Rare Diseases ; Renal Artery ; Stents ; Thromboembolism ; Thrombolytic Therapy ; Thrombosis ; Transplants ; Urokinase-Type Plasminogen Activator

No abstract available.
Autoradiography*