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Unlabelled: In patients with ischemic cardiomyopathy (CM), abnormal renograms may result not only from circulatory failure (which should reverse after transplantation) but also from intrinsic renal disease (which contraindicates heart transplantation). Here, the outcome of heart transplantation was related to preoperative renograms, and the differentiating and prognostic value of renography was analyzed., Methods: The study population consisted of 50 patients with ischemic CM expecting heart transplantation. Anatomical renal pathology was excluded in all patients. Dynamic renal scintigraphy was performed with 99mTc-mercaptoacetyltriglycine. Background-subtracted renograms were inspected visually and characterized numerically. Mean parenchymal transit time (mPTT), renal tracer content at 15 min (RTC15) and retention index (RI) were determined. The parametric renogram values were related to a normal reference group of 64 patients. The preoperative renograms were matched with the postoperative outcome., Results: Three characteristic types of symmetrical findings in the kidneys were found: no pathological findings, mildly delayed peak and excretion phase and severely delayed peak and excretion phase. Pathological renograms were observed in 36 of 50 (72%) patients. The mean parametric renogram values in ischemic CM were as follows: Group A (normal kidney function), mPTT = 142+/-26.6 sec, RTC15 = 22.3%+/-4.6% and RI = 24.7+/-11.9; Group B (mild dysfunction), mPTT = 210+/-44.0 sec, RTC15 = 42.6%+/-10.3% and RI = 101.4+/-50.5; Group C (severe dysfunction), mPTT = 320+/-94.2 sec, RTC15 = 79.6%+/-15.9% and RI = 347.7+/-194.7; and reference patients (normal kidney function), mPTT = 137+/-31.1 sec, RTC15 = 22.8%+/-3.8% and RI = 24.6+/-7.9. Postoperative serum creatinine levels were <1.5 mg/dl in all Group A patients, between 1.5 and 2.5 mg/dl in 78% of Group B patients and >2.5 mg/dl in 75% of Group C patients., Conclusion: Renography revealed abnormal kidney function when structural pathology was excluded. The renographic abnormalities in ischemic CM did not reflect simply the circulatory failure. The numerical grading of renograms allowed patient stratification, suggestive of possible renal insufficiency after cardiac transplantation and immunosuppressive therapy. With further experience, renography may become a useful tool for predicting postoperative outcome in ischemic CM.

This is the first article in a four-part series on scintillation camera quality control. This series of articles will include both theory and practical knowledge on setting up a quality control program, acceptance testing and quality control for planar, SPECT and special imaging procedures. On completion of this article the reader should be able to: (a) discuss the purpose of a quality control program; (b) know how to establish the performance criteria for a scintillation camera; (c) know how to design a quality control program; (d) be able to set up the schedule for the quality control program; (e) understand the economics of quality control; and (f) justify the expenditure of the institution's resources on quality control.

For the purpose of radiation dose estimates, organ assays and excretion measurements of the Tc-99m and In-111 complexes with DTPA were conducted in dogs at various time intervals up to 24 hr, and the results compared with available human data. The peak concentration of the Tc-99m complex, at 3 min after injection, was 5% of the administered dose for one kidney, 3.5% for the liver, and 3.5% for the small bowel. No organ system except the urinary tract reached a concentration higher than that in blood for several hours after the injection. The biliary excretion of these agents was extremely low, and their elimination in the feces was negligible. In man, it appears that the residual 4-5% of an administered dose not eliminated in the urine by 24 hr is widely distributed in various tissues. The distribution of the In-111 complex is similar but not identical to that of the Tc-99m complex.

Resting computerized transaxial tomography was performed after the i.v. injection of thallium-201 in six normal subjects and in five patients who had had myocardial infarctions 3 mo to 4 yr before scintigraphy. Decreased myocardial activity corresponded to the site of previous infarction in all cases and was clearly separated from adjacent myocardium with normal activity. With tomography, the left ventricle was clearly separated from surrounding structures such as the left-ventricular cavity, the lungs, and the liver. This study demonstrates the feasibility for the assessment of myocardial perfusion using single-photon transaxial emmission computed tomography.

Estimates of absorbed radiation dose and qualitative assessments of image resolution were compared for pure 131I and for 123I produced by the 122Te(d,n), 124Te(p,2n), and 127I(p,5n) 123Xe reactions. A substantial reduction in radiation dose is indicated when 123I replaces 131I, in spite of the radiocontaminants typically present 30-35 hr after the production of 123I by any of these methods. Only a marginal further reduction in radiation dose was noted with use of the most "pure" 123I as opposed to the least "pure" 123I. Comparable scintillation camera resolution was obtained for all 123I preparations at 30-35 hr after bombardment when the medium-energy and pinhole collimators were used. However, the radiocontaminants in the 123I produced from tellurium affected image resolution when the low-energy collimator was used.

These phantom studies and computer calculations provide a direct means of estimating the radiation dose to the embryo resulting from the administration of a radiopharmaceutical to the mother during organogenesis. The specific absorbed fractions to the embryo from 19 source organs were computed for 12 monoenergetic photon energies. Tables of absorbed dose per unit cumulated activity, S, for the embryo as a target organ have been assembled for 99mTc, 111In, 113mIn, 123I, 131I, and 133Xe. In addition, the dose to the embryo was calculated for several of the radiopharmaceuticals for which the MIRD Committee has published dose estimate reports.