The gallium scan: problems and misuse in examination of patients with suspected infection.

Gallium citrate Ga 67 (67Ga) has been used for almost ten years as a means of detecting inflammatory lesions in febrile patients. We have reviewed 80 cases from Milwaukee County General Hospital (1977 through 1979) in which 67Ga scanning was performed to detect inflammatory lesions in patients by suspected infection. Fifty scans also were available for review by the nuclear medicine staff. We found the sensitivity of 67Ga scans at our institution to be 90%, but specificity to be only 64%. In five (6%) of the cases, 67Ga scanning was the most important means of establishing a diagnosis. Of the 50 scans available for review, only 26 scans (52%) were interpreted in the same way as the original reading. Twenty-two (27%) of all scans in retrospect should not have been ordered, either because of the fever was gone and the patient's condition was improving or the diagnosis was already made. We conclude that 67Ga scans can be useful to detect inflammatory lesions but that they are frequently used inappropriately by physicians at our hospital, they are difficult to interpret, and the specificity is lower than the sensitivity.

Evaluation of postresuscitation left ventricular global and segmental function by radionuclide ventriculography in sudden coronary death survivors of prehospital cardiac arrest: Correlation to subsequent short-term prognosis.

Previous data have shown that patients with significant left ventricular (LV) dysfunction, marked abnormalities in resting hemodynamics, and multiple vessel coronary artery disease (CAD) are at increased risk for sudden cardiac death. However, in-hospital assessment of ventricular function in the early postresuscitation period of out-of-hospital cardiac arrest has not been evaluated and related to short-term outcome. By using bedside radionuclide ventriculography (RNV) we evaluated LV ejection fraction (LVEF) and wall motion in 36 nonconsecutive patients within 24 hours of their episode of out-of-hospital cardiac arrest. There were 24 men and 12 women with mean age of 62.3 years (range 21 to 85 years). Total mortality of the entire group was 38.8% at 4 weeks. Eighteen patients had LVEF less than 0.30 and 18 had LVEF greater than 0.30. Mortality in the low LVEF group was 55.5% at 4 weeks versus 22.2% in patients with LVEF greater than 0.30 (p less than 0.05). Patients with normal LV wall motion had no short-term mortality (none of seven), while patients having abnormal LV wall motion had a significantly higher short-term mortality (14 of 29) (p less than 0.05). We conclude that out-of-hospital cardiac arrest survivors have a high incidence of severe LV dysfunction in the early postresuscitation period and that a significantly higher early mortality is seen in the group with LVEF less than 0.30. In addition, abnormalities of LV wall motion by RNV examination demonstrated poorer prognosis in the first 4 weeks than patients with normal LV wall motion.

Bone scintigraphy in the reflex sympathetic dystrophy syndrome.

Sixty-four consecutive patients were studied for possible reflex sympathetic dystrophy syndrome (RSDS). They were divided into five groups, based upon specific clinical criteria, and the radiographic and scintigraphic findings in each group were examined. Osteoporosis was the most common radiographic abnormality, present in 69% of subjects with definite, probable, or possible RSDS, as compared with 21% opf those with RSDS. Scintigraphic abnormalities were noted in 60% of RSDS patients but in only 7% of the others. These findings included increased blood flow and enhanced periarticular radionuclide activity in the affected extremity. Of 11 patients with serial scintigraphy, six (55%) demonstrated a return to normal, symmetrical patterns following successful therapy. The scan may reflect an active, potentially reversible disorder of local blood flow in RSDS. Furthermore, the scintigraphic patterns may be useful in the diagnosis and in predicting which pattients are likely to respond to systemic steroid therapy.

The reflex sympathetic dystrophy syndrome (RSDS). III. Scintigraphic studies, further evidence for the therapeutic efficacy of systemic corticosteroids, and proposed diagnostic criteria.

Sixty-four patients were evaluated prospectively for a reflex sympathetic dystrophy syndrome (RSDS), using quantitative clinical measurements, high-resolution roentgenography and scintigraphy. Five separate groups were identified by their clinical features, allowing us to distinguish patients with definite or incomplete forms of the RSDS as well as 16 patients with other disorders. Scintigraphy was found to be a useful diagnostic study that may also provide a method of predicting therapeutic response. Systemic corticosteroid therapy proved to be a highly effective mode of treatment for up to 90 percent of the patients with the RSDS.

Unilateral increased radioactivity in the lower extremities on routine 99mTc-pyrophosphate bone imaging.

Unilateral increased activity in the lower extremities was noted in 5 patients who underwent routine 99mTc-pyrophosphate bone imaging for metastatic evaluation. In three patients a large pelvic mass or retroperitoneal hematoma was noted on the affected side. Clinical evidence of lymphatic obstruction was apparent in two cases with pelvic mass. In the fourth case, venous disease (thrombophlebitis) was noted and the fifth case showed osteomyelitis. The possible mechanism for this phenomenon may include obstruction of the lymphatic or venous circulation and inflammation. Other causes of soft tissue uptake of 99mTc-PYP are reviewed. The above mentioned conditions must be excluded when asymmetrical activity of 99mTc-PYP is seen on routine bone imaging.

Cardiac localization of 99mTc-(Sn)-pyrophosphate following irradiation of the chest.

Of 70 consecutive cancer patients referred from radiotherapy for bone scans, 32% showed cardiac uptake of 99mTc-(Sn)-pyrophosphate; only 9% of a control group showed this uptake. Of those with prior left hemithorax irradiation, 60% showed cardiac uptake; only 12% of those with irradiation elsewhere showed this phenomenon (p less than .01). The patients who had no increased uptake tended to have shorter irradiation-to-scan time intervals (less than 10 months) than those who did show increased uptake (mean of 22 months).

Quantitative estimation of 67Ga citrate in hypofunctioning thyroid nodules.

Quantitation of 67Ga citrate activity was performed in 11 subjects who underwent surgery for nonfunctioning, cold thyroid nodules. Radioactivity was measured in blood and in excised nodular and paranodular tissue at approximately 48 hours after the injection. Eight subjects were histologically benign, nonfunctioning nodules had no significant concentration of Ga. Their nodular/blood activity ratio was 1.6. In two patients with thyroid cancer, a higher activity was observed (mean 4.5/1). One patient with Hashimoto's thyroiditis also revealed a high concentration of Ga (5.3/1). Findings suggest that 67Ga citrate has a lesser affinity for benign cold nodules than for malignant and inflammatory lesions. More clinical experience is necessary before the significance of these observations can be assessed.

An unusual cause of apparent regional hyperperfusion on radionuclide cerebral angiography study: case report.

An unusual pattern of radioactivity in the venous phase was noted in the 99mTc-DTPA cerebral angiogram of a patient with persistent headaches. Initially the possibility of a small arteriovenous malformation with large draining veins was considered. However, contrast angiography revealed dilated cerebral veins with significant arteriovenous shunting. The differential diagnosis of regional hyperperfusion on the radioactivity study is discussed.

Pulmonary vascular complications in narcotic addicts.

Perfusion deficits on lung scanning in narcotic addicts are frequently demonstrable. To determine the angiographic and hemodynamic correlates of these deficits, right heart catheterization with selective pulmonary angiography was carried out in 7 addicts with abnormal lung scans, and one with normal scan. Four had angiographic abnormalities corresponding to the regions of perfusion defects on lung scan. These consisted of large vessel cut-offs, intraluminal filling defects and/or considerably reduced vascularity. Three subjects had normal angiograms in the presence of abnormal perfusion scans. One subject had normal angiogram and scan. All eight patients had normal pulmonary artery pressures and calculated pulmonary vascular resistances. This study demonstrates that (1) angiographic abnormalities in larger pulmonary arteries may be found in narcotic addicts with perfusion defects on lung scanning, and (2) these findings may be present without significant hemodynamic alterations.

Acute cerebral vascular accident associated with hyperperfusion.

Cerebral radionuclide angiography can demonstrate decreased or normal radioactivity in the affected region during the arterial phase in patients who have sustained a cerebral vascular accident and thus enhances the diagnostic specificity of the static brain image. In an occasional patient, however, a seemingly paradoxical pattern of regional hyperperfusion with a return to normal or subnormal perfusion following the acute phase has been observed. This phenomenon, called "luxury perfusion," has been defined using intra-arterial 133Xe for semiquantitative cerebral blood flow measurements and should be kept in mind as a potentially misleading cerebral imaging pattern.

Myocardial localization of 99mTc-pyrophosphate without evidence of acute myocardial infarction.

Localization of 99mTc-pyrophosphate in the cardiac region during routine bone scanning for metastatic tumor is discussed in two cases. Clinical information as well as electrocardiographic and serum enzyme studies did not reveal any evidence of acute myocardial injury. The cause of myocardial localization of the radiopharmaceutical is not clear in these cases.

Acute pulmonary alveolitis in narcotics abuse.

Lungs of 17 narcotic abusers from medical-legal autopsies were studied to determine the pathological basis for regional alterations of ventilation and perfusion. Postmortem pulmonary angiographic and histological techniques demonstrated acute alveolar wall inflammation with exudation of fluid and cells into the alveoli in all eight abusers dying of narcotism and in six of nine dying of other causes. All abusers had extensive focal chronic intersititial inflammatory infiltrates. Vascular obstruction due to foreign material occurred only with intravenous use of oral pharmaceuticals, and then only in the microcirculation. Lungs of ten young adults dying suddenly with no history or evidence of narcotics abuse showed no acute alveolitis or intravascular foreign material. Intravenous narcotics injection produces transient acute alveolar inflammation that may account for respiratory manifestations and death. Permanent injury to the lung parenchyma or larger vessels with the usual forms of narcotic abuse is not common.

Increased sensitivity of regional measurements in early detection of narcotic lung disease.

Intravascular foreign body thromboembolism and interstitial or vascular granulomata in the lungs are common sequelae to intravenous drug abuse. Early detection of such complications is important, because of the youthful population often involved. Conventional pulmonary function tests, including forced expiratory volumes, diffusion capacity for CO (DLco), chest radiograph and arterial blood gas analysis were performed in 23 narcotic addicts, most of whom had no pulmonary symptoms. The results were compared with radionuclide pulmonary function studies obtained following inhalation of 133Xe gas and injection of 99-mTc albumin microparticles. Thirteen subjects who had normal nonnuclear pulmonary function tests, including DLco and chest radiograph, demonstrated significant abnormalities of regional lung perfusion by lung scan. Of the ten subjects with abnormal DLco all had abnormal perfusion scans and five were noted to have hypoxia at rest. In addition, six of the ten subjects with abnormal DLco revealed a history of concomitant "solid pill abuse" along with heroin abuse, whereas only 2 of 13 subjects with normal DLco admitted tooccasional solid pill abuse. The perfusion lung scan is therefore a sensitive means for detection of early lung disease in narcotic addicts.

Measurement of regional lung function in the early detection of chronic obstructive pulmonary disease.

Radioisotopic regional lung function measurements using both 99mTc-labeled albumin microspheres and inhaled 133Xe were compared to measurements of total lung function in a population of 30 participants in an epidemiological study of the causative factors of obstructive pulmonary disease. Five of the 8 asymptomatic subjects who had no evidence of obstruction by the tests of total function had abnormal regional lung function measurements. The closing volume was abnormal in three of these five, suggesting the presence of small airways disease. Regional lung function was abnormal in all subjects who were symptomatic, who had a FEV1/FVC less than 75%, or who had an elevated closing volume or residual volume. The data indicate that the measurement of regional lung function may be a highly sensitive test for the early diagnosis of chronic obstructive pulmonary disease.