Anil G. Desai

Planar and SPECT Tc-99m red blood cell imaging in hepatic cavernous hemangiomas and other hepatic lesions.

The utility of Tc-99m BBC imaging in the diagnosis of hepatic cavernous hemangiomas has been established. Of the 25 patients with various focal hepatic lesions evaluated, 16 were diagnosed as having hemangiomas: eight proven by surgery, two proven by angiography, and six proven by maintaining a stable clinical course ranging from 6 to 12 months with normal follow-up liver function tests. Although fourteen of these were detected by planar imaging, two were detected by SPECT only. Two patients with large hemangiomas had false-negative scans, whereas the remaining seven patients had other liver lesions.

Radiolabeled Blood Cells: Techniques and Applications

During the past few years, the clinical and experimental applications of autologous blood cells labeled with gamma-emitting radionuclides, i.e., technetium-99m (Tc-99m) and indium-111 (In-111) have continued to grow rapidly. Investigations have centered around developing techniques that would label blood cells efficiently without alteration of cell viability and their pathophysiologic integrity. Experimental and clinical applications have been aimed at the studies of in vivo cell kinetics and detecting abnormal lesions by external imaging. These will be discussed in detail together with their advantages and disadvantages, and the future directions will be outlined.

Drug-induced gallium uptake in the breasts

Intense symmetrical Ga-67 accumulation was observed in the breast of a young female and was attributed to the hyperprolactinemic effect of drugs.

Spontaneous osteonecrosis of the knee. Scintigraphic findings.

Three cases of spontaneous osteonecrosis (SON) of the knee, comprised of two cases involving the medial tibial plateau and one involving the medial femoral condyle, are reported. Because of the relatively normal x–rays early in the course of the disease, the differential diagnosis of a painful knee is markedly shortened with the typical scintigraphic findings in SON. The scintigraphic findings represent a focal area of increased activity at the affected site on a three–phase bone scan.

Renal allograft rejection. Unusual scintigraphic findings

During sequential renal imaging for evaluation of clinically suspected rejection, focal areas of functioning renal tissue were seen in two cases of renal transplant in the midst of severe and irreversible renal allograft rejection. A probable explanation for this histopathologically confirmed and previously unreported finding is discussed.

Technetium-99m pyrophosphate scintigraphy for the detection of acute myocardial infarction. How useful is it?

To evaluate the contribution of Tc-99m pyrophosphate scintigraphy (TPS) on the overall management of patients suspected of having acute myocardial infarction (AMI), hospital records of 58 consecutive patients who underwent TPS, were evaluated in depth. The results indicate that TPS was essential for the diagnosis of AMI in 16% of the patients. TPS was most rewarding in perioperative patients and in patients with borderline or uninterpretable electrocardiographs and enzyme changes. Also, in some cases, TPS was able to confirm or exclude the diagnosis of AMI prior to the confirmation by serial electrocardiograms (ECG) and serial enzyme changes. TPS was less rewarding in patients with clinically low index of suspicion for AMI. It may also be confusing in patients with high clinical likelihood of AMI and a history of prior myocardial infarction because of the possibility of persistently positive TPS in some of these patients. Considering the limitations of ECGs, the cardiac enzymes, and atypical clinical presentations in the patient population we evaluated, TPS appears to be fairly accurate when the scintigraphic findings are compared with the final diagnosis at the time of discharge from the hospital.