A lesion was identified on the late images of a hepatobiliary scintigraphic study, but was not detected on the very early images, due to its enlarged blood pool. This combination of scan findings has ...not been previously described. The implication of the observation is that one must examine all the images of the hepatobiliary study in an effort to detect space-occupying lesions of the liver.
We describe interesting imaging features on a FDG-PET scan in a patient with bony metastases from a rare tumor. The lesions were obscured by intense bone marrow activity after the administration of ...hematopoietic factor at the time of diagnosis. Correlative MRI, CT scan, and pathology findings have also been illustrated. Follow-up FDG-PET scan demonstrated the hypermetabolic lesions.
The usual method of generating net Hippuran renal uptake curves involves the administration of a blood pool agent. Two techniques are presented which permit the determination of net renal uptake ...curves from data intrinsic to the Hippuran study. This reduced the complexity of the procedure, as well as reducing its cost and decreasing the radiation exposure. The new procedures were tested in 9 patients and showed excellent correlation with the blood pool agent technique.
Examination of the time course of left ventricular ejection has been found useful in several clinical applications. Equilibrium gated radionuclide angiography provides non-invasive means to obtain ...the ventricular ejection curve. To evaluate the accuracy of the equilibrium gated radionuclide left ventricular volume curve we compared equilibrium gated radionuclide date with biplane cine-angiography in 16 patients examining each set of data on a point by point basis. The cine-angiographic data consisted of 60 frame per second biplane cineangiograms and the radionuclide data consisted of 28 points spanning the cardiac cycle. All data was normalized for the patient's heart rate and stroke volume. The equilibrium gated radionuclide angiographic data accurately reproduced the contrast angiographic data at each point on the curve. This result justifies using the equilibrium gated radionuclide time activity curve to evaluate parameters such as early systolic ejection rates or rates of maximum ventricular ejection.
A patient who had recently received a therapeutic dose of Na131I showed no 99mTc activity on the scintillation camera when a pertechnetate brain scan was attempted. Subsequent experiments showed ...that, when even small amounts of 131I are present in the field of view of a scintillation camera equipped with a collimator designed for low-energy photons, counting rates from 99mTc are markedly affected.
Some of the erythrocytes labeled using an in vivo technique are sequestered by the spleen and thus lost from the circulation. Allowance for this loss must be made if calculations regarding relative ...changes in ventricular volumes are being made over extensive periods of time.
A prospective study of eight patients with recent transmural myocardial infarction was performed using 99mTc-Sn-pyrophosphate and 99mTc-Sn-methylene diphosphonate in each patient. All pyrophosphate ...scans were strongly positive whereas the diphosphonate scan was strongly positive in only one case. We conclude that 99mTc-Sn-pyrophosphate is preferable to 99mTc-Sn-methylene diphosphonate for myocardial imaging.
