Intravenous adenosine (adenoscan) versus exercise in the noninvasive assessment of coronary artery disease by SPECT.

Fifteen patients at a mean age of 58 underwent adenosine and maximal exercise thallium SPECT imaging. All scans were performed 1 week apart and within 4 weeks of cardiac catheterization. SPECT imaging was performed after the infusion of 140 micrograms/kg/min of adenosine for 6 minutes. Mean heart rate increment during adenosine administration was 67 +/- 3.7 to 77 +/- 4.1. Mean blood pressure was 136 +/- 7.2 to 135 +/- 6.2 systolic and 78 +/- 1.8 to 68 +/- 2.6 diastolic. No adverse hemodynamic effects were observed. There were no changes in PR or QRS in intervals. Five stress ECGs were ischemic. No ST changes were observed with adenosine. Although 68% of the patients had symptoms of flushing, light-headedness, and dizziness during adenosine infusion, symptoms resolved within 1 minute of dosage adjustment or termination of the infusion in all but one patient, who required theophylline. Sensitivity for coronary artery detection was 77% and specificity 100%. Concordance between adenoscans and exercise thallium scintigraphy was high (13/15 = 87%). In two patients, there were minor scintigraphic differences. The authors conclude that adenosine is a sensitive, specific, and safe alternative to exercise testing in patients referred for thallium imaging and may be preferable to dipyridamole.

An unusual case of pulmonary emboli.

The authors present an interesting case of pulmonary embolus serendipitously diagnosed during an evaluation for a presumed metastatic pulmonary nodule.

Initial experience with SPECT imaging of the brain using I-123 p-iodoamphetamine in focal epilepsy.

Nineteen patients with complex partial seizures refractory to medical treatment were examined with routine electroencephalography (EEG), video EEG monitoring, computed tomography or magnetic resonance imaging, neuropsychological tests and interictal single photon emission computed tomography (SPECT) with I-123 iodoamphetamine (INT). In 18 patients, SPECT identified areas of focal reduction in tracer uptake that correlated with the epileptogenic focus identified on the EEG. In addition, SPECT disclosed other areas of neurologic dysfunction as elicited on neuropsychological tests. Thus, IMP SPECT is a useful tool for localizing epileptogenic foci and their associated dynamic deficits.

Exercise first-pass radionuclide assessment of left and right ventricular function and valvular regurgitation in symptomatic mitral valve prolapse.

The changes in right ventricular (RV) and left ventricular (LV) function and in regurgitant fractions on first-pass exercise radionuclide angiography (RNA) were assessed in 29 consecutive patients with symptomatic mitral valve prolapse (MVP). The mean right ventricular ejection fraction (RVEF) was 35 +/- 8% at rest and 46 +/- 15% after exercise (p less than 0.001). The mean left ventricular ejection fraction (LVEF) was 62 +/- 11% at rest and 74 +/- 13% after exercise (p less than 0.001). Seven of 29 patients had an abnormal RV response and 6 had an abnormal LV response. Eight had abnormal wall motion after exercise. A total of 12/29 patients (41%) had one or more abnormalities. The mean left-sided regurgitant fraction before exercise was 27 +/- 17% in 21/29 patients (72%) and 31 +/- 21% after exercise (p = ns). An additional 5 patients (17%) developed left-sided regurgitation after exercise. These findings indicate that wall motion abnormalities and abnormal RVEF and LVEF responses to exercise occur in symptomatic MVP patients. In addition, 26/29 (89.6%) had left-sided regurgitation after exercise. Since the presence of a murmur did not correlate with the presence of mitral regurgitation by RNA, then symptomatic patients with MVP should have first-pass exercise RNA to assess the presence of regurgitation at rest and after exercise. Antibiotic prophylaxis is recommended in MVP patients with systolic murmurs or with regurgitation. Since patients without murmurs can have regurgitation, further study is necessary to determine the need for endocarditis prophylaxis in these patients.

The effect of intraosseous sodium bicarbonate on bone in swine.

Five domestic swine weighing 8 to 12 kg were anesthetized with ketamine 20 mg/kg IM and pentobarbital 20 mg/kg IV. After a sterile prep each animal received NaHCO3 1 mEq/mL/kg in one tibia and saline 1 mL/kg in the other. The animals were allowed to recover and were observed for 30 days. At the end of this period, roentgenographs were obtained of each tibia and triple phase 99m technetium bone scans were obtained. The tibias also were sectioned, stained, and examined under light microscopy for microscopic abnormalities. The only deficit found was a small cortical calcification at the site of the needle puncture in an animal that received NaHCO3. All other roentgenographs, bone scans, and microscopic specimens were normal. This study demonstrates that NaHCO3 does not have permanent adverse effects when injected into the marrow cavity of swine and supports previous clinical observations regarding the safety of NaHCO3.

Ilioportal shunt during a venogram/lung scan.

An interesting case of ilioportal shunting in a patient with seminoma and infrarenal thrombosis of the inferior vena cava, iliac and femoral veins is presented. This case demonstrates the utility of the nuclear venogram/lung scan for revealing venous collaterals in an ilioportal shunt, and illustrates shunting of femoral venous drainage into the mesenteric circulation, the portal veins, and the liver.

The radionuclide diagnosis of horseshoe kidney.

The authors present an interesting case of horseshoe kidney diagnosed by nuclear imaging.

Hepatobiliary-lung imaging. A case report.

The use of combined hepatobiliary-lung imaging in the diagnosis and evaluation of a subphrenic process is described.

Radionuclide esophageal and intestinal transit scintigraphy in patients undergoing radiation therapy.

Radiation esophagitis and enteritis are common and significant side effects of radiation therapy. Non-invasive assessment of functional and/or anatomic changes responsible for the symptoms produced by radiation esophagitis and enteritis has been unsatisfactory. This paper demonstrates the value of radionuclide esophageal and intestinal transit scintigraphy in patients undergoing mediastinal or abdominal radiation.

Subcapsular bile leak following percutaneous drainage.

The authors describe the scintigraphic appearance of a case of subcapsular biliary leak. Hepatobiliary scintigraphy using Tc-99m labeled radiopharmaceuticals is employed primarily for the diagnosis of acute cholecystitis and for the demonstration of biliary tract patentcy. This procedure can also provide functional and morphologic information for evaluation of biliary tract trauma.

A positive indium-III bone marrow scan in metastatic breast carcinoma. Case report.

Indium is generally presumed to localize in the bone marrow within the erythroid cell line. Fibrosis, inflammation, lymphoma, extended field radiation, chemotherapy, or combinations of both treatment modalities generally depress the uptake of indium by the marrow a complex fashion. We report a case of metastatic breast carcinoma and pancytopenia in which the In-111 scan appeared qualitatively similar to a Tc-99m MDP bone scan. Findings were confirmed by bone marrow biopsy.

Gallium localization in peritonitis. Two case reports.

Diffuse abdominal localization of gallium was found in two patients with peritonitis, one due to M. tuberculosis and the other presumably pyogenic. Gallium scanning may be useful in the diagnosis of peritonitis and perhaps of other serosal infections.