Gerald S. Johnston

Glucose utilization of cerebral gliomas measured by [18F] fluorodeoxyglucose and positron emission tomography

Positron emission tomography was used to measure local cerebral glucose utilization by the 2-[18F]fluoro-2-deoxy-D-glucose technique in 23 patients with cerebral gliomas. All 10 high-grade (III and IV) astrocytomas demonstrated a region of high activity with a glucose consumption of 7.4 ± 3.5 (SD) mg/100 gm per minute. The 13 low-grade (I and II) gliomas had a glucose metabolic rate of 4.0 ± 1.8 mg/100 gm per minute, with no distinctly visible hot spot. Thus, we found a correlation between rate of glycolysis and malignancy in primary cerebral tumors. Cerebral cortical glucose utilization was often depressed in areas adjacent to or neurally connected to the tumor site, and there was focal irregular delta wave EEG activity in these areas.

Tissue Signatures with Dual-Energy Computed Tomography

By providing information on two parameters, dual-energy computed tomography can offer clinically useful tissue signatures for metallic deposits (Ca) or injected iodine, as well as for different normal and abnormal types of brain parenchymal tissues and CSF. Cerebral CT was performed on 36 patients and tissue differences analyzed using Hounsfield notation.

Radionuclide scanning and microangiography of evolving an completed brain infarction A correlative study in monkeys

A correlative study between sequential radionuclide brain scanning and time-lapse microangiograms has been carried out in an experimental model of ischemic cerebral infarct in monkeys. In the majority of animals, brain scintigraphy became positive by two weeks, then regressed toward negative by four to six weeks after ligation of the middle cerebral artery. Increased radioisotope uptake is clearly related to neovascularization around the area of infarct as shown by the microangiograms. At later stages, decreased vascularity, peripheral gliosis, and central cavity formation are the main factors determining diminution of radionuclide penetration in the involved area.

Renal localization of gallium-67 citrate.

Renal localization of 67Ga citrate has been observed in 1.7% of 2,000 whole-body gallium scans in three major diseases: lymphoreticular neoplasms, leukemia, and malignant melanoma. Correlation of this finding with autopsy data in 13 cases revealed 9 with tumor and 2 with an inflammatory process. Findings in two cases were normal. In the remaining patients, correlation with abnormal urograms and laboratory data was poor. Nevertheless, gallium localization in the kidneys may be the first indicator of renal involvement with either tumor or inflammation.

Clinical Correlations of 67Ga and Skeletal Whole-Body Radionuclide Studies with Radiography in Ewing's Sarcoma

Twenty-seven patients with Ewings 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.

67Ga radionuclide imaging in Burkitt's lymphoma.

Whole-body gallium imaging was evaluated as a diagnostic tool for 14 patients with Burkitts lymphoma, and a dramatic gallium affinity for the tumor was demonstrated. The gallium image is recommended as a staging procedure and as an effective test for determining the therapeutic response.

67Ga-Citrate Scintigraphy of Brain Tumors

67Ga localization by brain tumors was seen in 19 of 21 patients with known brain tumors. Two negative studies were obtained from patients with slowly-growing tumors. Approximately 1/3 of the tumors were imaged more clearly with 67Ga than with 99mTc, but localization of both isotopes appeared to be related to the type of tumor, degree of malignancy, and previous therapy.

“Normal” Bone Radionuclide Image with Diffuse Skeletal Lymphoma

A case of diffuse skeletal involvement by lymphoma is presented. Bone scan was interpreted as normal, but gallium scans and roentgenograms revealed the proper diagnosis. A possible explanation for this discrepancy is offered.

Brain Scintigraphy with 99mTc Pertechnetate, 99mTc Polyphosphate, and 67Ga Citrate

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.

Erythropoietic responses to acute and chronic ureteral occlusions in dogs

Abstract Arterial and renal vein plasmas obtained from 58 nonanemic, nonuremic dogs subjected to unilateral ureteral occlusions acutely or for a period up to 5 weeks were assayed for ESF in the plethoric mouse. Despite the wide range of renal blood flows, resistances, and pO 2 levels, detectable elevations of ESF were not frequently observed. Complete or incomplete ureteral occlusions, infusion of vasoconstrictive agents, or the absence of the contralateral intact kidneys did not influence the ESF values. Elevation of arterial and renal vein ESF levels occurred only in animals subjected to acute ureteral occlusions at the level of the renal pelvis. These findings are discussed in the light of recent evidence for extrarenal control and release of ESF.