Simultaneous technetium-99m MIBI angiography and myocardial perfusion imaging.

Resting first-pass radionuclide angiography (FPRNA) was performed with the myocardial perfusion agent technetium-99m MIBI. In 27 patients, it was compared with technetium-99m diethylenetriamine pentaacetic acid FPRNA. A significant correlation was present in left (r = 0.93, p less than 0.001) as well as right (r = 0.92, p less than 0.001) ventricular ejection fraction measured with both radiopharmaceuticals. In 13 patients, MIBI derived segmental wall motion was compared with contrast ventriculography. A high correlation was present (p less than 0.001), and qualitative agreement was found in 38/52 segments. In 19 patients with myocardial infarction a significant correlation was present between MIBI segmental wall motion and perfusion scores (p less than 0.001). In ten patients with a history of myocardial infarction, 18 myocardial segments demonstrated diseased coronary vessels and impaired wall motion at contrast angiography. These segments were all identified by the MIBI wall motion and perfusion study. We conclude that MIBI is a promising agent for simultaneous evaluation of cardiac function and myocardial perfusion at rest.

Biodistribution, dosimetry, and clinical evaluation of technetium-99m ethyl cysteinate dimer in normal subjects and in patients with chronic cerebral infarction.

Technetium-99m ethyl cysteinate dimer (ECD) has high initial cerebral uptake with slow clearance in nonhuman primates suggesting ideal characteristics for single photon emission computer tomography (SPECT) imaging. We evaluated the biodistribution, dosimetry and scintigraphic pattern of [99mTc]ECD in normal subjects and the accuracy of SPECT imaging in patients with chronic cerebral infarction. Sixteen normal subjects were injected with approximately 10 mCi of [99mTc]ECD. Anterior and posterior single-pass whole-body images were obtained at multiple times after injection. Blood clearance of the radiotracer was rapid, falling to 10.0 +/- 6.6% and 4.9 +/- 1.1% of the injected dose at 2 and 60 min, respectively. Brain uptake was 6.4 +/- 2.1% of the injected dose 5 min after injection. The critical organ was the urinary bladder. Technetium-99m ECD SPECT was performed with a rotating gamma camera in ten of the 16 normal subjects and 34 patients with clinical and CT evidence of chronic stroke. Thirty-three of the thirty-four patients had focal [99mTc]ECD abnormalities on SPECT (97.1%) based on visual inspection of the SPECT images. In summary, we obtained high quality SPECT images as a result of the optimal physical and biologic characteristics of the tracer. Technetium-99m ECD SPECT shows promise for the evaluation of patients with stroke.

Technetium-99m sestamibi myocardial imaging at rest for assessment of myocardial infarction and first-pass ejection fraction. Multicenter Cardiolite Study Group.

The ability of technetium (Tc)-99m sestamibi myocardial perfusion imaging at rest to evaluate myocardial infarction and first-pass ejection fraction was studied in a trial involving 18 institutions. Protocol I compared regional perfusion with occurrence of infarction by Q wave or by gated blood pool scan wall motion abnormality in 146 patients. Protocol II assessed first-pass right and left ventricular ejection fraction in 85 patients. In protocol I, Tc-99m sestamibi images were abnormal in 104 of 111 patients (94%) with both a Q wave and a gated scan wall motion abnormality and was normal in 23 of 25 patients (92%) in whom both were normal. Therefore, concordance existed in 105 (94%) patients. Of 115 patients with a Q wave, 107 (93%) had an abnormal Tc-99m sestamibi study. Of 115 patients with a gated scan wall motion abnormality, 108 (94%) had an abnormal Tc-99m sestamibi study. Tc-99m sestamibi imaging showed corresponding perfusion abnormalities in 81% of 69 anterior Q-wave infarcts, 73% of 55 inferior Q-wave infarcts and 88% of 8 posterior infarcts. Specificity in normal regions on electrocardiography and wall motion was 91, 100 and 100%, respectively, for anterior, inferior and posterior regions, respectively, between wall motion and perfusion. Of 17 myocardial segments per patient, there was concordance in 74% of patients. First pass Tc-99m sestamibi imaging of ejection fraction agreed well with conventional first-pass imaging for the right and left ventricle. It is concluded that Tc-99m sestamibi myocardial imaging at rest reliably diagnoses and localizes infarction and assesses ejection fraction by first-pass imaging.

Myocardial contusion in the stable patient: what level of care is appropriate?

To evaluate the significance of myocardial contusion, we evaluated 243 stable patients hospitalized for blunt chest trauma between 1982 and 1986. The groups were identified according to results of radionuclide angiography, mean injury severity score (ISS), and outcome. Group I (n = 71; mean ISS = 12.7) patients were those without myocardial contusion by radionuclide angiography. Two patients with cardiac complications were in this group. The patients with myocardial contusion were divided into two groups. Group II (n = 69; ISS = 19.5) patients had myocardial contusion as an isolated injury, and group III (n = 103; ISS = 30.9) patients had myocardial contusion and injury to at least one other organ system. Three patients from group II had cardiac complications. Eleven patients from group III had cardiac complications. There were no significant differences between the cardiac complication rate in the three groups, and each complication was present when the patient arrived in the emergency department. The predicted mortality rate based on ISS was 10% to 20% for patients with myocardial contusion, whereas the observed mortality rate for the groups (II and III) overall was 0.58%. We conclude that in the stable trauma patient myocardial contusion (1) does not by itself increase the risk of complication, (2) does not necessitate intensive care unit monitoring, (3) should be devalued when computing ISS scores, (4) may account for lengthy and often unnecessary hospitalization, and (5) in patients at risk for complications may be identified by ECG abnormalities on arrival to the emergency department.

Cholescintigraphy in AIDS-related cholangitis: a case report.

Acalculous inflammatory biliary disease has been reported in patients with acquired immune deficiency syndrome (AIDS). AIDS-related cholangitis manifests the intrahepatic and extrahepatic biliary changes seen in sclerosing cholangitis, including strictures, dilatation, and decreased arborization. Biliary scanning was used to evaluate a patient with suspected AIDS-related cholangitis. The hepatobiliary images showed prompt hepatic uptake, with nonvisualization of the gallbladder, common bile duct, and bowel at two hours. Thus, the overall hepatic clearance time approached infinity. There was also a central photopenic region at the porta hepatis. ERCP confirmed the diagnosis of AIDS-related cholangitis. Infection with cytomegalovirus is the proposed etiology. AIDS-related cholangitis should be included in the differential diagnosis of an obstructive cholescintigraphic pattern.

Cerebral hypoxic injury detected by Tc-HMPAO SPECT.

Single photon emission computed tomography of the brain with Tc-99m labeled hexamethylpropyleneamine oxime was used to evaluate a patient who suffered hypoxic cerebral injury. Hypoperfusion in the right parieto-occipital and left occipital regions was demonstrated on the SPECT images, while both the cranial CT and EEG failed to document the findings.

Evaluation of patients with chest pain and nondiagnostic ECG using thallium-201 myocardial planar imaging and technetium-99m first-pass radionuclide angiography in the emergency department.

STUDY OBJECTIVE: The purpose of this study was to determine if thallium-201 myocardial planar imaging and technetium-99m first-pass radionuclide angiography, performed in the emergency department, could predict which patients with acute chest pain and nondiagnostic ECGs were more likely to have an acute myocardial infarction (AMI). DESIGN: Retrospective analysis. SETTING: Urban, county ED. TYPE OF PARTICIPANTS: Convenience sample of 47 patients with acute chest pain suggestive of myocardial ischemia and nondiagnostic ECG. INTERVENTIONS: Thallium-201 myocardial imaging and technetium-99m first-pass radionuclide angiography in the ED. MEASUREMENTS AND MAIN RESULTS: Four patients had an AMI (ie, CK-MB greater than or equal to 6% total CK). The combined scans had a sensitivity of 75%, (95% confidence interval [Cl], 19-99%), a specificity of 42% (95% CI, 27-58%), an accuracy of 45% (95% CI, 19-99%), a positive predictive value of 11% (95% CI, 2-29%), and a negative predictive value of 95% (95% CI, 75-100%) in predicting AMI. CONCLUSION: Thallium-201 myocardial planar imaging and technetium-99m first-pass radionuclide angiography performed in the ED do not appear to be useful in determining which patients with acute chest pain and nondiagnostic ECG are likely to have an AMI.

Scintimammography: the complementary role of Tc-99m sestamibi prone breast imaging for the diagnosis of breast carcinoma.

PURPOSE: To evaluate the complementary role of technetium-99m sestamibi scintimammography in improvement of the sensitivity and specificity of mammography in detection of carcinoma of the breast. MATERIALS AND METHODS: At 5 and 60 minutes after intravenous injection of Tc-99m sestamibi, scintimammograms were obtained in 147 women (age range, 18-73 years; mean age, 47.9 years +/- 10.2 [standard deviation]) with 153 lesions that warranted breast biopsy (102 lesions) or fine-needle aspiration cytologic analysis (51 lesions). There were 113 palpable and 40 nonpalpable lesions. Lesion size on mammograms was 0.8 x 0.6 cm to 15.0 x 11.0 cm (mean, 2.82 cm +/- 1.71 x 2.39 cm +/- 1.56). RESULTS: Scintimammographic findings were true-positive in 47 biopsy-confirmed carcinomas, true-negative in 91 benign lesions, false-positive in 11 lesions with benign histopathologic findings (fibrocystic disease [n = 8] or fibroadenoma [n = 3]), and false-negative in four lesions of infiltrating ductal carcinoma. The sensitivity of scintimammography was 92.2%; specificity, 89.2%; positive predictive value, 81.0%; and negative predictive value, 95.8%. CONCLUSION: The authors conclude that scintimammography is a sensitive test that can improve the detection of breast carcinoma.