Gallium Scanning in the 'New' Tuberculosis

Abstract

Ga-67 scanning is more sensitive than routine chest radiography for detection of both TB parenchymal lung involvement and adenopathy. Ga-67 imaging facilitates the choice of biopsy sites by identifying accessible peripheral nodes. Typical patterns in recent cases of TB differ significantly from the upper lobe predilection of classical TB.

Radionuclides in Pulmonary and Extra-Pulmonary Tuberculosis

“…An advantage of using 67Ga to investigate suspected infection is its ability to image the whole body. This may give rise to incidental findings (Grieff and Lisbona 1991;Lin and Hsieh 1999), and also facilitates determination of the most appropriate biopsy site by exposing involved accessible peripheral nodes (Goldfarb et al 1997).…”

“…The traditional upper lobe presentation is the exception rather than the rule; lower lobe disease and adenopathy are more common (Goldfarb et al 1995(Goldfarb et al , 1997Abdel-Dayem et al 1997). Parenchymal lesions are more heterogeneously distributed than would be expected in traditional pulmonary tuberculosis (Goldfarb et al 1995), and it becomes difficult to differentiate other opportunistic infections on the basis of the 67Ga distribution alone.…”

“…This forms the basis of a more definite differentiation from other opportunistic infections. The presence of lymph node uptake, in the presence or absence ofparenchymal uptake, raises the possibility of tuberculous involvement; whereas a lack of uptake in the lymphoid regions suggests that the disease is unlikely (Goldfarb et al 1995(Goldfarb et al , 1997Parmett et al 1995;Santin et al 1995;Abdel-Dayem et al 1997). Such lymph node accumulation does, however, make differentiation from lymphoma more difficult because of the similar presentation of these two entities (Kramer et al 1989).…”

“…Imaging with 67Ga is a very sensitive indicator of the presence of active tuberculosis (Siemsen et al 1978;Moody and Delbeke 1992;Kao et al 1993) and seems more accurate than physical examination of the neck or plain X-rays of the chest (Goldfarb et al 1997). Active disease results in a positive image in up to 97% of patients (Siemsen et al 1976(Siemsen et al , 1978Walsh et al 1985;Lin and Hsieh 1999).…”

“…In patients with AIDS, 67Ga scintigraphy is also a very sensitive technique for localizing sites of tuberculous infection (Palestro et al 1991;Santin et al 1995;Abdel-Dayem et al 1997;Goldfarb et al 1997). A normal 67Ga distribution is very suggestive of an absence of active disease (Lee et al 1994;Santin et al 1995), but cannot exclude the possibility completely (Utsunomiya et al 1997).…”