[en] 403 equilibrium gateel nuclear angiocardiographics were processed automatically. The selection of the left ventricular sampling region is based on the zero harmonic data (Ho method). The threshold is defined as the highest count rate density (counts/pixel) in the end-diastolic frame, which is not associated with significant cyclic changes (Hi method). Either the Ho or Hi method would fail 9% of the recordings and both in 9% of the cases. (WU)

No abstract available

No abstract available

[en] The value of ventilation studies in conjunction with pulmonary perfusion scintigraphies for the diagnosis of pulmonary emboli is reviewed. A retrospective study of 273 consecutive cases and comparison with 42 angiographic results provides the data base. The data are compared with previously reported results and confirm the diagnostic gain obtained by ventilation studies. Possible advantages of the use of krypton-81m for the ventilation study are suggested. Finally, with the observed prevalence of six possible scintigraphic outcomes and assuming that two outcomes are diagnostic, it can be shown that the addition of a ventilation study in the diagnostic work-up decreases the average cost of the diagnosis

[en] The authors state in their preface:''...we believe that there is no book yet available in which computing in nuclear medicine has been approached in a reasonable manner. This book is our attempt to correct the situation.'' The book is divided into four sections: (1) Clinical Applications of Quantitative Scintigraphic Analysis; (2) Mathematical Derivations; (3) Processing Methods of Scintigraphic Images; and (4) The (Computer) System. Section 1 has chapters on quantitative approaches to congenital and acquired heart diseases, nephrology and urology, and pulmonary medicine

[en] The value of radioisotope bone scanning at the time of presentation and serially during follow-up has been evaluated in 55 patients with biopsy-proven osteogenic sarcoma. Many of the patients studied were treated with adjuvant chemotherapy. Bone metastases were detected at presentation in only one patient and in a second patient, proximal extension of the primary tumor not evident on radiographs was demonstrated by the radioisotope technique. During fellow-up, 20 patients experienced bone metastases and each had an abnormal bone scan. Eleven of these patients were asymptomatic for bone metastases at the time the scan became abnormal. Seven patients experienced bone metastases as their first site of tumor recurrence. The detection rate for soft tissue metastases was low, but the scan indicated stump recurrence in three patients. Although the yield is small, bone scanning is justified at presentation be cause the results may profoundly after the management. During follow-up, routine bone cans are indicated in all patients, whether they have symptoms or not

[en] Prior to the introduction of adjuvant chemotherapy it was suggested that isotope bone scanning in the follow-up of patients with osteosarcoma should be reserved for those who have been successfully treated for lung metastases. We have performed 245 bone scans in 47 patients receiving chemotherapy for osteosarcoma, during a mean follow-up period of 28 months. Bone scans were abnormal in all 20 patients with proven bone metastases (sensitivity 100%), 11 being asymptomatic when the scan became abnormal. In 7 patients bone was the first site of metastases. Four patients had false positive bone scans (specificity 85%). Lung metastases were detected by bone scanning in only 4 of 28 cases, in 1 case the bone scan giving the first evidence of their presence. Three of 5 patients with intense focal uptake at the amputation stump at more than 6 months postoperatively had local recurrence. We conclude that serial bone scans are valuable in all patients receiving chemotherapy for osteosarcoma, but are too insensitive to screen for soft tissue metastases. (Author)

[en] In 3 patients, each of whom had previously had part of one kidney included within the field during radiation therapy, whole-body bone imaging using /sup 99m/Tc-pyrophosphate showed increased activity in the irradiated renal segment. Possible mechanisms of such renal uptake are discussed

[en] The book is a conglomerate of formal papers, discussions, and the textual minutes of a round table discussion with audience participation. The first part, and most interesting from my view-point, deals with the perception of risk or harm and societal attitudes. The second part contains papers that seem to be historical primers concerning radiobiology. This subject is surrounded by controversy, and it seems in part to be approached as an elephant would be by a tribe of blind zoologists. They poke and pinch, sometimes describe small parts in great detail, but never exactly circumscribe the object of the study. The purpose is to present a discussion of the harm due to radiation, specifically radiation from power sources. Closely related to this is the question of the regulatory agencies' role

[en] Features extracted from static or dynamic scintigraphic images can be used to produce parametric or functional images. Those images typically map a dynamic parameter (temporal encoding) or a quantitative measure of the tracer distribution. In this report, we consider the cases in which the nature of the extracted feature is well suited for a quantitative normative evaluation, ie, where the values obtained can be directly or indirectly compared with expected normal values. The major difference between this approach and the more common heuristic or synoptic interpretation of images lies in the underlying modeling: the model predicts a minimal washout rate, a match between ventilation and perfusion rates in the lungs, homogeneous contraction in the left ventricle, an expected angular distribution of thallium in the myocardium, or the absence of an additional kinetic feature. The quantitative aspect of the analysis is based in all cases on an approach that overcomes or is less sensitive to morphological or structural biological variability: in some cases the patient provides the normalizing data, as in ventilation-perfusion ratios. In other cases, the model predicts homogeneous results (as in phase analysis) or a range of normal physiological values (for xenon washout). Less commonly, the analysis requires a transformation of the data, as is the case in the analysis of myocardial perfusion, which follows a polar transformation of the image, and an analysis based on angular coordinates