Acquired immunodeficiency syndrome: Ga-67 citrate imaging

All gallium-67 citrate scans obtained in patients with acquired immunodeficiency syndrome (AIDS) at the Clinical Center, National Institutes of Health (Bethesda, Md.) were retrospectively analyzed and correlated with the results of bronchoscopy, chest radiography, and endoscopy. There were 164 scans of 95 patients. Twenty scans were from patients with Pneumocystis carinii pneumonia; 19 were abnormal, for a sensitivity of 95%. Ga-67 uptake tended to be less in patients receiving therapy for P. carinii pneumonia. Chest radiographs were normal at least initially in three patients with abnormal scans and P. carinii pneumonia. Unusually prominent colonic activity was associated with infection in some patients. No lesions of Kaposi sarcoma showed tracer uptake. Gallium scanning is useful for detecting P. carinii pneumonia and other opportunistic infections in patients with AIDS, but it is not useful for localizing Kaposi sarcoma.     

Diagnostic significance of apparent abnormal bowel activity on Ga-67 scans in AIDS patients

Twenty-one Ga-67 studies on 19 AIDS patients were analyzed to investigate the relationship between clinically acute gastrointestinal disease and abnormal scintigraphic bowel activity. Whole body images were obtained at times ranging from 4 to 192 hours, with most exams imaged at 48 and 72 hours. Abnormal bowel activity was observed in eight of 21 exams. Patients experienced acute GI disease during seven studies. Gallium scan results and clinical presentation agreed in 14 cases; both were abnormal in four and normal in 10. However, four exams showed abnormal activity in asymptomatic patients, while three normal studies were obtained in patients with clinically evident GI disease. Sensitivity was 57% and specificity 71%. Positive predictive value was .50 and negative predictive value .77. All true-positive cases were associated with Mycobacterium avium intracellulare (MAI) infection. This study implies that gallium imaging is unreliable for diagnosing acute bowel disease in AIDS patients, but may suggest a particular pathogen (MAI) in the symptomatic individual.     

Demonstration of Ga-67 localization in human placenta

Gallium-67 uptake was noted in the mid-pelvic uterine area of a 19-week-pregnant female. Lateral and oblique Ga-67 scans revealed an anterior location of radioactivity that correlated with the position of the placenta as determined by ultrasonic technique.     

Diagnostic ultrasound patterns of parotid glands in human immunodeficiency virus-positive patients in Mulago,Uganda

Objectives

The purpose of this study was to determine sonographically, in parotid glands of human immunodeficiency virus-positive patients, the condition of glands with or without enlargement, and propose a classification system for the patterns observed using diagnostic ultrasound imaging.

Methods

In this prospective clinical study, ultrasound scans were performed on 200 patients aged 4–62 years at Mulago Hospital, Uganda.

Results

There were four main distinct ultrasound pathological patterns in the parotids, i.e. lymphocytic aggregations (LAs), lymphoepithelial cysts (LECs), fatty infiltration (FI) and lymphadenopathy only. There were additional subdivisions depending on the presence of echogenic foci and intraparotid lymphadenopathy. Of those patients (n = 64) without parotid enlargement, only 8% showed normal ultrasound features, whereas 34% showed LECs and 31% showed LAs. Of those (n = 136) with parotid enlargement, 46% showed LECs, 23% showed FI and 15% showed LAs. The overall prevalence of LECs in the study sample was 42%. LECs were multiple, mainly between 7 mm and 12 mm in diameter and 26% showed internal echogenic foci either mobile or stationary. In contrast, LAs tended to be ill-defined, less than 5 mm and were not associated with posterior acoustic enhancement. Features differentiating LAs from LECs have not been previously described. Parotid FI (lipodystrophy) was noted in patients on highly active antiretroviral therapy, who showed lesser prevalence of LECs after 12 months of treatment.

Conclusions

Our study of 200 patients is probably the largest such study in the English language literature. The wide spectrum of diagnostic ultrasound patterns was categorized into four main groups (ten subgroups).     

Ga-67 scintigraphy in patients with breast lymphoma.

PURPOSE: The authors studied the utility of Ga-67 citrate scintigraphy in patients with breast lymphoma. METHODS: Seven patients with histologically proved breast lymphoma were examined. In three patients, both breasts were involved, and all patients had rapidly growing breast masses. Planar and SPECT images were obtained 72 hours after injection of Ga-67. RESULTS: Ga-67 scintigraphy showed intense accumulation in all lymphomas. SPECT images provided better contrast than did planar images. In one of the seven patients, the axilla and mediastinum were also involved. In six of the seven patients, Ga-67 scintigraphy was also performed after treatment and showed the disappearance of Ga-67 accumulation. In one patient with local recurrence and lung involvement, abnormal accumulation was depicted on follow-up Ga-67 scintigraphy. CONCLUSIONS: Ga-67 scintigraphy was helpful to confirm the diagnosis and the systemic extent of lymphoma and to evaluate the therapeutic effect during follow-up in patients with breast lymphoma.     

Ga-67 scintigraphy in chromomycosis

We examined an interesting case of chromomycosis that had a characteristic Ga-67 accumulation. This patient had had widespread chromomycosis skin lesions for 8 years. We performed Ga-67 scintigraphy in an attempt to obtain additional information on the site and extent of the lesion. Ga-67 scintigraphy revealed not only all subcutaneous nodules but also an unsuspected enlarged lymphnode and a visceral lesion. This case indicates that Ga-67 scintigraphy is a very useful method to use in detecting the site and extension of chromomycosis, especially in the nodal and the visceral lesions, and sometimes might help in differential diagnosis.     

Ga-67 studies in a patient with acquired immunodeficiency syndrome and disseminated mycobacterial infection

A well-documented case of acquired immunodeficiency syndrome (AIDS) with diffuse lymphadenopathy and disseminated mycobacteriosis in whom serial Ga-67 studies were performed is presented.     

Ga-67 uptake in diethylstilbestrol-induced gynecomastia. Experience with six patients

Six patients who had been treated with diethylstibestrol (DES) for prostatic cancer had symmetrical breast uptake of Ga-67. Of these patients, five proved to have DES-induced gynecomastia. The minimum dose and administration period of DES required for Ga-67 uptake in gynecomastia is discussed.     

Normal and abnormal Ga-67 SPECT anatomy in patients with lymphoma

The appearance of normal Ga-67 SPECT images in the coronal, sagittal and transaxial planes is described. The normal tomographic appearance of bone, liver, spleen, and gut is shown and compared with disease involvement above and below the diaphragm.     

Lung hilar Ga-67 uptake in patients with lymphoma following chemotherapy

Scintigraphic characteristics of lung hilar Ga-67 uptake (HU) and their relationship with the etiology (benign vs. malignant) of the hilar lesions in lymphoma patients following chemotherapy were retrospectively investigated. A total of 161 lymphoma patients were included in the study. The presence/absence of HU and if present, symmetry/asymmetry and intensity of HU (on the basis of a 3 scale grading system) were visually and semiquantitatively assessed on transaxial sections of thorax Ga-67 SPECT. By drawing ROIs over right and left hilum, asymmetry index (AI%) was also calculated. HU was categorized as benign or malignant depending on the radiological correlation and clinical follow-up. In the malignant group, the majority of patients (85.7%) had grade 2 or grade 3 uptake and all had asymmetric pattern. However, in the benign group, grade 1 uptake was more common (66%) and was mainly symmetric (94.6%) in appearance. AI% in the malignant group (73.7 +/- 36.6) was significantly higher than in the benign group (5.7 +/- 4.9) confirming the marked asymmetry in malignant patients.     

Clinical use of Ga-67 DFO-DAS-fibrinogen

The clinical usefulness of 67Ga-DFO-DAS-fibrinogen, a newly developed thrombus imaging agent, was evaluated. Fifteen cases were given 2 mCi of 67Ga-DFO-DAS-fibrinogen and images were obtained up to 96 hours after injection. Abnormal accumulation of 67Ga-DFO-DAS-fibrinogen was imaged in seven cases with either venous or arterial thrombi, and no side effects were noted. These results suggested that 67Ga-DFO-DAS-fibrinogen might be a promising agent for thrombus imaging.     

Clinical application of Ga-67 DFO-DAS-fibrinogen

Scintigraphy with 67Ga-DFO-DAS-fibrinogen (67Ga-fibrinogen) was performed for the positive delineation of thrombi in patients with suspected venous or arterial thrombus formation. Five out of 17 patients showed 67Ga-fibrinogen accumulation corresponding to thrombus formation, as confirmed by other examination including radionuclide venography, contrast angiography, and CT scan. There was some difference in 67Ga-fibrinogen uptake between venous and arterial thrombi. With arterial thrombi, 67Ga-fibrinogen uptake was observed over one year after the appearance of clinical symptoms of dissecting aneurysm and arteriosclerosis obliterans. However, with venous thrombi, 67Ga-fibrinogen uptake occurred less than three weeks after the onset of venous edema. These results may indicate different mechanisms of thrombus organization between venous and arterial thrombi. Further, the thrombi age seems to be an important factor in analyzing the diagnostic accuracy of radioagents used for thrombus scintigraphy.