Noninflammatory entities and the differential diagnosis of positive three phase bone imaging.

The greater sensitivity of skeletal imaging over radiography (93% vs. 50%) for the detection of early osteomyelitis is well known. The introduction of the three phase protocol has improved the specificity of skeletal imaging by eliminating various noninfectious entities; however, the occurrence of false-positive studies is not unusual. Four such cases have been observed by the authors in a group of 34 patients suspected of having osteomyelitis and who had positive three phase skeletal imaging. These includes a patient with giant cell tumor, synovial cell sarcoma, gouty arthritis, and Reiter's syndrome. A description of these cases and a brief review of several other entities associated with positive three phase bone imaging is the subject of this atlas article, which should serve as an aid in the differential diagnosis of this commonly performed scintigraphic procedure.

Lateral position test and quantitative lung scan in the preoperative evaluation for lung resection.

The postpneumonectomy FEV1 was predicted in 24 patients with severe chronic obstructive pulmonary disease (FEV1 less than or equal to 2.0 L) and a lung mass using the quantitative lung scan (QLS) and lateral position test (LPT). Although a good correlation (r = .72, p = 0.0006) was found between the FEV1 predicted by QLS and LPT, there was more than 10 percent difference between the result in 59 percent of the subjects. A subgroup of these patients performed multiple (two to five) LPTs, and the results were calculated blindly to assess variability. The variation seen was 14 times greater than in previously reported normal subjects. Calculations suggest that as many as 37 tracings would be needed on each patient to obtain an acceptably low measurement error. Whereas there was a good overall correlation between the predicted postpneumonectomy FEV1 using both methods, the variability found with LPT would suggest extreme caution in its use.

Gallium citrate Ga 67 scans in febrile patients.

Scanning with gallium citrate Ga 67 is a sensitive technique for the detection of localized inflammatory disease. In a group of 22 febrile patients, 17 had one or more abnormal areas of radioactive gallium localization. Eight patients showed localized areas of inflammation; five showed no area of local inflammation within the field of the scan. The remaining patients had excellent clinical and laboratory confirmation of neoplastic or inflammatory disease. These cases illustrate the usefulness of radioactive gallium in febrile patients in whom the cause of the fever cannot be otherwise determined.

Diagnosis of an enteric duplication with pertechnetate 99mTc scanning.

A case of enteric duplication is reported in which preoperative pertechnetate (99m)Tc scanning demonstrated localized uptake in the region of the anatomic abnormality. This test is recommended for use in the evaluation of lower gastrointestinal bleeding in infants and children.

Technetium 99m sulfur colloid spleen/liver ratio and other liver tests in the diagnosis of cirrhosis.

The results of seven laboratory tests of liver function, including spleen/liver activity ratios obtained by densitometric analysis of scans, are analyzed in 50 patients with proven Laennec's cirrhosis. In this series, the liver scan not only disclosed the liver gross anatomy and structural abnormality and established the best possible site for biopsy examination, but also, the increased splenic activity served as a useful diagnostic indication of Laennec's cirrhosis. Of 50 proven cases of Laennec's cirrhosis, 41 (82%) had abnormal spleen/liver ratios. An abnormal spleen/liver ratio in combination with abnormal results from any one or two other tests was relatively effective in the detection of cirrhosis. The accuracy is improved if the other laboratory tests are chosen from among tests for serum albumin, serum bilirubin, and SGOT. (Liver abnormalities other than cirrhosis can also present an abnormal spleen/liver ratio.) This simple determination extends the value of the liver scan commonly requested in search of metastases, primary lesions, or inflammatory processes, or in preparation for needle biopsy examination.