AC improved specificity in the evaluation of right CAD in overweight men. In the other evaluable subgroups specificity was not significantly affected while sensitivity was frequently reduced.

Because little has been published on early effects of treatment with amiodarone on thyroid function, we studied serum total and free thyroid hormone, reverse T3, and TSH levels in patients with cardiac arrhythmias during the first 10 days of treatment with a loading dose of amiodarone by iv infusion. Twenty-four patients were enrolled in the study. A standardized loading regimen for the i.v. infusion of amiodarone was used. The protocol provided the i.v. infusion of 20 mg/kg per day on day 1, the i.v. infusion of 10 mg/kg per day on day 2, then 600 mg/day per os for 7-10 days, and finally, in patients chronically treated with the drug, the dose was gradually reduced to 400-200 mg/day per os. Total and free concentrations of T4 tended to progressively and significantly increase (P < 0.0001 repeated measures ANOVA) starting from the fourth day of therapy, whereas total T3 decreased from the second day progressively (P < 0.0001) throughout the study; free T3 did not significantly change. TSH levels early and significantly (P < 0.001, by ANOVA) increased throughout the study, starting from the first day of therapy and reaching at 10 days a value 2.7 times higher than the basal value. Reverse T3 levels progressively and significantly (after 2 days of treatment) increased and paralleled the TSH values, reaching at the 10th day a value about 2 times higher than basal value. In conclusion, our data suggest that after i.v. treatment with amiodarone: 1) TSH is the first hormone to change significantly followed by reverse T3, T4, and T3; 2) the progressive fall of T3 levels reflects an inhibition of the peripheral conversion of T4 to T3; 3) the observed later increase of total and free T4 levels may be explained by a contribution of direct thyroidal stimulation by TSH and/or by a reduction in T4 clearance.

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Objective The aim of this study was to propose and verify a universal method of left ventricular myocardium segmentation, able to operate on heart gated PET data with different sizes, shapes and uptake distributions. The proposed method can be classified as active model method and is based on the BEAS (B-spline Explicit Active Surface) algorithm published by Barbosa et al. The method was implemented within the Pmod PCARD software package. Method verification by comparison with reference software and phantom data is also presented in the paper. Methods The proposed method extends the BEAS model by defining mechanical features of the model: tensile strength and bending resistance. Formulas describing model internal energy increase during its stretching and bending are proposed. The segmentation model was applied to the data of 60 patients, who had undergone cardiac gated PET scanning. QGS by Cedars-Sinai and ECTb by Emory University Medical Centre served as reference software for comparing ventricular volumes. The method was also verified using data of left ventricular phantoms of known volume. Results The results of the proposed method are well correlated with the results of QGS (slope: 0.841, intercept: 0.944 ml, R 2 : 0.867) and ECTb (slope: 0.830, intercept: 2.109 ml, R 2 : 0.845). The volumes calculated by the proposed method were very close to the true cavity volumes of two different phantoms. Conclusions The analysis of gated PET data by the proposed method results in volume measurements comparable to established methods. Phantom experiments demonstrate that the volume values correspond to the physical ones.