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Although 123I-MIBG has been in clinical use for the imaging of pheochromocytoma for many years, a large multicenter evaluation of this agent has never been performed. The present study was designed to provide a prospective confirmation of the performance of 123I-MIBG scintigraphy for the evaluation of patients with known or suspected primary or metastatic pheochromocytoma or paraganglioma. Methods A total of 81 patients with a prior history of primary or metastatic pheochromocytoma or paraganglioma and 69 with suspected pheochromocytoma or paraganglioma based on symptoms of catecholamine excess, CT or MRI findings, or elevated catecholamine or metanephrine levels underwent whole-body planar and selected SPECT 24 h after the administration of 123I-MIBG. Images were independently interpreted by 3 masked readers, with consensus requiring agreement of at least 2 readers. Final diagnoses were based on histopathology, correlative imaging, catecholamine or metanephrine measurements, and clinical follow-up. Results Among 140 patients with definitive diagnoses (91, disease present; 49, disease absent), 123I-MIBG planar scintigraphy had a sensitivity and specificity of 82%. For patients evaluated for suspected disease, sensitivity and specificity were 88% and 84%, respectively. For the subpopulations of adrenal (pheochromocytoma) and extraadrenal (paraganglioma) tumors, sensitivities were 88% and 67%, respectively. The addition of SPECT increased reader confidence but minimally affected sensitivity and specificity. Conclusion This prospective study demonstrated a sensitivity of 82%–88% and specificity of 82%–84% for 123I-MIBG imaging used in the diagnostic assessment of primary or metastatic pheochromocytoma or paraganglioma.

This prospective multicenter trial of (123)I-mIBG scintigraphy documents high sensitivity and specificity of this imaging technique in patients with both newly diagnosed and previously treated neuroblastoma.

Eighteen consecutive patients with acute spontaneous perinephric hemorrhage were examined with computed tomography (CT) (n = 18), ultrasonography (US) (n = 15), and angiography (n = 9). Renal cell carcinoma was found in 10 patients; angiomyolipoma, three; and segmental renal infarction, arteriovenous malformation (AVM), hemorrhagic cyst, abscess, and idiopathic hemorrhage, one each. Initial CT examinations demonstrated the extent of hemorrhage in all cases and a distinct mass in 12 (67%), with CT characteristics suggestive of the correct diagnosis in 11. In the other six patients (33%), a discrete mass was not seen at initial CT, and in five cause of hemorrhage was not clear. Two of the five underwent follow-up CT, which correctly demonstrated carcinoma in both. Overall, CT findings suggested the correct diagnosis in 14 patients (78%). US was sensitive for detection of an abnormality but nonspecific as to its nature. Angiography demonstrated unsuspected AVM in one patient, segmental renal infarction seen at CT in one, but only one of five carcinomas suspected at CT. Data from this study suggest that CT is the most valuable examination for patients with spontaneous renal hemorrhage.

Single photon emission computed tomography (SPECT) perfusion brain scans with iodine-123 isopropyl iodoamphetamine (IMP) were obtained in 12 subjects who acknowledged using cocaine on a sporadic to a daily basis. The route of cocaine administration varied from nasal to intravenous. Concurrent abuse of other drugs was also reported. None of the patients were positive for human immunodeficiency virus. Brain scans demonstrated focal defects in 11 subjects, including seven who were asymptomatic, and no abnormality in one. Among the findings were scattered focal cortical deficits, which were seen in several patients and which ranged in severity from small and few to multiple and large, with a special predilection for the frontal and temporal lobes. No perfusion deficits were seen on I-123 SPECT images in five healthy volunteers. Focal alterations in cerebral perfusion are seen commonly in asymptomatic drug users, and these focal deficits are readily depicted by I-123 IMP SPECT.

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To determine the impact of radiographic findings on the interpretation of bone and gallium scans of patients with active osteomyelitis, the authors reviewed the medical records and radiologic examinations of 104 patients. The only diagnostic finding of active disease on radiographs was the presence of a sequestrum (three patients). Other findings--such as erosion, soft-tissue swelling, and periosteal reaction--proved nonspecific and did not differentiate active from inactive disease. Furthermore, these findings did not significantly change the sensitivity or specificity of the bone and gallium scans, either in detecting or in excluding the presence of active disease.

Conventional radiographs, technetium-99m bone scans, and gallium-67 scans were reviewed in 44 patients who had undergone cemented total hip joint replacement and were imaged because of suspicion of prosthesis loosening or infection. A complete radiolucent line of 2 mm or wider along the bone-cement interface or metal-cement lucency on conventional radiographs was used as the criterion for prosthetic loosening with or without infection and proved to be 54% sensitive and 96% specific. Scintigraphic criteria for prosthetic loosening were increased focal uptake of the radiopharmaceutical for the femoral component and increased focal or diffuse uptake for the acetabular component. For bone scintigraphy, sensitivity was 73% and specificity was 96%. Combining the results of conventional radiographs and bone scans increased sensitivity to 84% and decreased specificity to 92% for the diagnosis of loosening, infection, or both. The study also showed that Ga-67 scintigraphy has a low sensitivity for the detection of infection.