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Twenty-seven patients with Ewing's sarcoma were evaluated by whole-body radionuclide studies, using 67Ga citrate and 18F or 99mTc polyphosphate. Correlative diagnostic radiography was performed on all patients. Gallium scanning, bone scanning, and roentgen rays were of equal usefulness in diagnosing the primary lesion. Skeletal metastases were evaluated most effectively with bone scanning, 12 of 13 cases being thus detected, whereas 8 of 13 were detected on gallium images and 4 of 13 on radiographs. Lung metastases were found in 7 of 8 cases with radiography but in only 1 of 8 gallium scans.

Vasogenic cerebral edema was induced cryogenically in rhesus monkeys. Serial scans in both axial and coronal planes were used to study the onset, peak, and regression of edema. Progression of edema, predominantly involving the white matter, was analyzed from the postmortem distribution of a blood/brain barrier indicator (Evans blue) injected at surgery. Specific gravity was measured in fresh, unfixed specimens from both the edematous and normal hemispheres and correlated with corresponding CT attenuation values obtained before death. The drop in specific gravity closely corresponded to the decrease in CT attenuation.

The potentially fatal interstitial pneumonia of Pneumocystis carinii is a frequent opportunistic invader of patients treated for malignancy with immunosuppressive and cytotoxic agents. Generalized Ga-67 pulmonary localization which is markedly disproportionate to the clinical and radiographic findings has led to earlier diagnoses by open lung biopsy in this setting. The potential usefulness of gallium scintigraphy in patients with suspected P. Carinii pneumonia is presented.

Nineteen patients with known or suspected neoplasms of the skull and/or brain were studied with 99mTc pertechnetate, 99mTc polyphosphate, and 67Ga citrate. Lesions of the calvaria were detected most accurately with 99mTc polyphosphate. In some cranial lesions, 67Ga citrate localized within the core, 99mTc polyphosphate outlined the periphery, and 99mTc pertechnetate demonstrated the entire affected area. In postcraniotomy patients, the combination of 67Ga citrate and 99mTc polyphosphate provided a basis for distinguishing the surgical scar from a recurrent intracranial tumor. Purely intracerebral lesions were generally poorly localized with 99mTc polyphosphate.