[en] A 50-year-old man with hypercalcemia related to Cope syndrome was referred for bone scintigraphy. There was a clear accumulation of the technetium-phosphate complex in the stomach. The condition was reversible with treatment of the underlying cause

No abstract available

[en] Right ventricular ejection fraction (RVEF) calculated from ECG-gated steady-state ^81mKr angiocardiography and from ^99mTc first-pass studies were compared in 30 patients using a digital, single crystal, gamma-camera. Despite the two entirely different approaches RVEF valves obtained by the two methods were comparable (r=0.97): the mean absolute difference between the two techniques was 2.5%+/-1.5% and the largest observed absolute difference was 5%. In the absence of an accepted reference method for measuring RVEF, this close correlation provides indirect validation of both techniques. The choice of method will therefore depend on several factors, including radiotracer availability, the characteristics of the gamma-camera and the protocol of clincal investigation. (orig.)

[en] In the beginning of Parkinson disease, the fixation of Ioflupane ¹²³I (Dat-scan) is generally asymmetric. When the absolute fixation of the dopaminergic tracer is not clearly reduced, a significant asymmetry contributes to recognize a beginning disease. The objective of this study was to establish the usual limits of a fixation symmetry. As conclusions, the method used, virtually independent of the operator allows to identify objectively an abnormal asymmetry of fixation at the chosen threshold of signification, fixed in our study to 2 standard deviations of the symmetry average in our population of normal reference. (N.C.)

[en] Glomerular filtration rate (GFR) may be computed using the kinetics of the renal distribution volume curve Vt=rT/Pt and power fit of the plasma curve Pt=Potsup(-B). It can be demonstrated that GFR=d(Vt)/d(t)(1-B). The method is largely independent of background subtraction, allowing nonequivocal renal function determination in all cases. In a preliminary series of 20 patients, the linear regression coefficient of computed GFR with true clearance measurement by multiple blood samples method was 0.97 with a standard error on the estimate of the clearance of 5.5 ml. (author)

[en] Published in summary form only

[en] Published in summary form only

[en] The physical characteristics of krypton-81m makes it particularly suited for the study of right ventricular function, but its ultrashort half-life (13.3 s) precludes in vitro measurements of blood pool specific activity needed for count based determination of ventricular volumes. A combined geometric count based method was developed to measure absolute right ventricular volumes during steady state krypton-81 m angiocardiography: background corrected ventricular count rates were converted to volumes using a count to volume calibration factor calculated in an 'internal reference ROI' located in the right ventricular outflow tract. Stroke volumes calculated with this method were shown to be comparable to thermodilution determined stroke volumes and the ability of the method to monitor changes in right ventricular volumes was demonstrated during intervention studies. (author)

[en] The accuracy of a steady-state 81mKr method for calculating the right ventricular ejection fraction (RVEF) has been examined in this study. Causes of errors using this method and their effects on the calculated RVEF were evaluated. The results suggested that mixing in the right ventricle during continuous infusion of 81mKr was homogenous, allowing for the calculation of ejection fraction using the count rate ratio. Lung activity was quite important and could not be neglected in computing RVEF, but the use of [/sup 99m/Tc]MAA lung perfusion scanning seemed to allow a correct subtraction of this background activity. The delineation of right ventricular regions of interest (ROIs) was complicated by the translation movements of the right ventricle during heart contraction. These ROIs should be drawn carefully on the count density distribution images and data shown by parametric images; such as first and second harmonic phase, amplitude images, and composite stroke volume image should be considered. Furthermore, this study demonstrates the superiority of the 81mKr technique compared with /sup 99m/Tc methods for computing RVEF. In conclusion, even if the true accuracy of the 81mKr method for calculating RVEF cannot be proven due to the lack of reference methods, strong, suggestive evidence that the technique should be accurate is shown here

No abstract available