Splenic uptake of both technetium-99m diphosphonate and technetium-99m sulfur colloid in sickle cell beta (0) thalassemia.

A 19-year-old black woman with sickle cell beta(0) thalassemia had experienced more than 100 hospital admissions for sickle cell crisis and aseptic necrosis of both femoral heads. Her spleen was enlarged threefold and accumulated both radiocolloid and bone-seeking agent on two occasions, demonstrating an exception to the rule in sickle cell anemia that spleens that take up bone-seeking agents demonstrate functional asplenia. In the context of fever, left upper quadrant pain, and splenomegaly, the pattern of calcification in the patient's spleen as revealed in ultrasound and CT studies suggested possible abscess and led to unnecessary splenectomy. The nuclear medicine studies did not support this diagnosis. Nuclear medicine physicians should not be misled by splenic findings of sickle cell thalassemia (and possibly of other heterozygous sickle cell disorders) that differ from those of the more familiar homozygous sickle cell anemia.

Confirmation of brain death with portable isotope angiography: a review of 204 consecutive cases.

Intravenous isotope angiography is a rapid, safe, and specific bedside test for confirming brain death by demonstrating the lack of critical cerebral perfusion that occurs in this condition, regardless of etiology. A review of 204 consecutive cases of suspected brain death studied with isotope angiography has reaffirmed our confidence in the specificity of the technique and has convinced us to make less stringent our radiographic criteria for confirming brain death by this method. A technically satisfactory single flow study that shows arrest of the carotid circulation at the base of the skull and absence of the intracranial arterial circulation may be considered confirmatory of a carefully established clinical diagnosis of brain death, even though there may be some visualization of the intracranial venous sinuses. Arbitrary waiting periods, withdrawal of sedative drugs, and electrophysiological studies are not needed when this technique is used.

Tc-99m labeled leukocytes: preparation and use in identification of abscess and tissue rejection.

A simple and reproducible method for the preparation and labeling of leukocytes with Tc-99m has been developed. Leukocytes were separated from blood, incubated with stannous pyrophosphate, and then with 20-30 mCi (740-1110 MBq) of 99mTcO-4. In leukocytes separated from human blood, the labeling efficiency was 81% +/- 6% (n = 4). Experiments on dogs with abscesses showed accumulation of the Tc-99m-labeled leukocytes in the infected sites, indicating the viability of the labeled leukocytes. Additional studies showed that rat lymphocytes that were labeled with Tc-99m, using the same technique, localized in heart transplant tissue that was being rejected.

Improved myocardial infarct localization by combination of scintigraphy and ventricular wall motion evaluation.

Localization of acute myocardial infarcts can be done directly by imaging 99mTc pyrophosphate in the infarcted myocardium, or indirectly by analysis of wall motion abnormalities. Combining these modalities improves the sensitivity and specificity of the study. Forth-nine consecutive abnormal studies were analyzed in which both wall motion and static images were obtained with a single injection of pyrophosphate. At least 50% of the acute infarcts were better localized (or additional information obtained) by combining the modalities.

Confirmation of brain death at bedside by isotope angiography.

Documentation of the absence of cerebral circulation is useful as a confirmatory test of brain death. Intravenous isotope angiography performed at the bedside with a mobile gamma camera is a safe, convenient, rapid, reliable, and easily understood method of proving the absence of cerebral blood flow that occurs in brain death.

Use of radioisotope scan in evaluation of intrascrotal lesions.

There were 98 patients with a variety of intrascrotal lesions studied with a radioisotope 99mtechnetium-pertechnetate scanning technique. Retrospective analysis in 50 patients subjected to an operation revealed a 94 per cent accuracy of the scan in the differential diagnosis of testicular torsion and epididymitis as compared to a clinical accuracy of 48 per cent. In 7 patients with a scan diagnosis of epididymo-orchitis with abscess the diagnosis was confirmed during the operation or by followup examination. While the scan has been a simple, safe, rapid and reliable technique to differentiate acute and subacute lesions, it has proved to be of limited diagnostic significance in cases of chronic intrascrotal lesions and carcinoma.