No abstract available

No abstract available

No abstract available

[en] For routine thyroid scanning, the sodium pertechnetate Tc-99m scan is preferred over sodium iodide I-131 scanning in many laboratories. Radiation safety for the patient and reduction of costs are the primary reasons for this. Discrepancies can occur between iodine scans (iodine I-123 and ¹³¹I) as compared with /sup 99m/Tc scans: e.g., a nodule appearing cold on an iodine scan may be warm with a /sup 99m/Tc scan. To give other examples of discrepancies that can occur when /sup 99m/Tc is compared with iodine, we present two cases

No abstract available

[en] The presence of high numbers of somatostatin receptors seems to be the basis for the successful control by Sandostatin of hormonal hypersecretion by most growth hormone-secreting pituitary adenomas, endocrine pancreatic tumors, and carcinoids. In this report, we present preliminary data on in vivo somatostatin receptor imaging with a ¹²³I-coupled somatostatin analog (204-090) in patients with these types of tumors

[en] A number of different tumors have receptors for somatostatin. We evaluated the efficacy of scanning with ¹²³I-labeled Tyr3-octreotide, a somatostatin analogue, for tumor localization in 42 patients with carcinoid tumors, pancreatic endocrine tumors, or paragangliomas. We then evaluated the response to octreotide therapy in some of these patients. Primary tumors or metastases, often previously unrecognized, were visualized in 12 of 13 patients with carcinoid tumors and in 7 of 9 patients with pancreatic endocrine tumors. The endocrine symptoms of these patients responded well to therapy with octreotide. Among 20 patients with paragangliomas, 8 of whom had more than one tumor, 10 temporal (tympanic or jugular), 9 carotid, and 10 vagal tumors could be visualized. One small tympanic tumor and one small carotid tumor were not seen on the scan. The ¹²³I-labeled Tyr3-octreotide scanning technique is a rapid and safe procedure for the visualization of some tumors with somatostatin receptors. A positive scan may predict the ability of octreotide therapy to control symptoms of hormonal hypersecretion

[en] The effects of octreotide in vivo and in vitro on hormone release, in vivo [¹²³I]Tyr3-octreotide scanning, and in vitro [¹²⁵I]Tyr3-octreotide autoradiography were compared in five patients with endocrine pancreatic tumors. [¹²³I]Tyr3-octreotide scanning localized the primary tumor and/or previously unknown metastases in four of the five patients. The patient with a negative scan had an insulinoma that did not respond to octreotide in vivo. No Tyr3-octreotide-binding sites were subsequently found at autoradiography of the tumor, whereas somatostatin-14 receptors were present at a high density. In parallel, culture studies with the cells prepared from this adenoma showed that insulin release was not affected by octreotide, while both somatostatin-14 and -28 significantly suppressed hormone release. Culture studies of the tumor cells from two gastrinomas showed a dose-dependent inhibition of gastrin release by octreotide. Octreotide exerted direct antiproliferative effects in one of these gastrinomas, which had been shown to be rapidly growing in vivo. Both gastrinomas had specific somatostatin receptors, as measured by in vitro receptor autoradiography. Somatostatin release by the cultured somatostatinoma cells from one of these patients was suppressed by octreotide

[en] A fully automated procedure for the computation of left-ventricular ejection fraction (EF) from cardiac-gated Tc-99m blood-pool (GBP) scintigrams with fixed, dual, and variable ROI methods is described. By comparison with EF data from contrast ventriculography in 68 patients, the dual-ROI method (separate end-diastolic and end-systolic contours) was found to be the method of choice; processing time was 2 min. Success score of dual-ROI procedure was 92% as assessed from 100 GBP studies. Overall reproducibility of data acquisition and analysis was determined in 12 patients. Mean value and standard deviation of differences between repeat studies (average time interval 27 min) were 0.8% and 4.3% EF units, respectively, (r=0.98). The authors conclude that left-ventricular EF can be computed automatically from GBP scintigrams with minimal operator-interaction and good reproducibility; EFs are similar to those from contrast ventriculography

[en] Short communication