IMAGING INFECTION 

The Quarterly Journal of Nuclear Medicine 1999 March;43(1):61-73

Copyright © 2000 EDIZIONI MINERVA MEDICA

lingua: Inglese

Nuclear medicine imaging in fever of unknown origin

Peters A. M.

From the Department of Nuclear Medicine Addenbrooke’s Hospital, Cambridge, UK

Patients pre­senting ­with undi­ag­nosed ­fever gen­er­ally ­fall ­into two ­broad ­groups: ­firstly, ­those ­with co-­existing dis­ease or ­recent sur­gery, and sec­ondly ­those ­with ­pyrexia but who are oth­er­wise ­more or ­less ­well. A pyo­genic ­cause for ­fever is sig­nif­i­cantly ­more ­likely in the ­first ­group as com­pared ­with the ­second. Radio­nu­clide ­agents ­which are cur­rently ­freely avail­able for inves­ti­gating undi­ag­nosed ­fever are ­labelled leu­ko­cytes, 67Ga, and radio­lab­elled ­human immu­no­glob­ulin (HIG). ­Labelled leu­ko­cytes are gen­er­ally pref­er­able in the ­group ­with co-­existing dis­ease (­occult infec­tion), ­whereas 67Ga ­should be ­used in the ­second ­group, ­which can appro­pri­ately be ­called ­fever of ­unknown ­origin (FUO). The ­lower spec­i­ficity of 67G can be per­ceived as an advan­tage in ­this con­text in ­view of the ­wide ­range of pathol­o­gies ­capable of ­causing FUO. The ­role of HIG in undi­ag­nosed ­fever is unset­tled. In gen­eral, 67Ga is ­more ­helpful ­than ­labelled leu­ko­cytes ­when the ­cause of an FUO is intra­tho­racic, ­although the ­reverse is ­likely to be ­true for ­intra-abdom­inal ­causes, ­partly ­because of phys­io­log­ical excre­tion of 67Ga in the gut. Post­op­er­a­tive ­fever is an indi­ca­tion for a leu­ko­cyte ­scan. ­Patients ­with hae­mat­o­log­ical malig­nan­cies occa­sion­ally ­present as an FUO, but ­patients ­with ­chronic ­renal dis­ease ­should be ­approached as ­occult infec­tion. Inves­ti­gating chil­dren ­with undi­ag­nosed ­fever is a par­tic­u­larly dif­fi­cult ­problem. For the ­future, we ­need ­agents ­which are par­tic­u­larly effec­tive for loc­al­ising ­chronic inflam­ma­tion and, of sec­on­dary impor­tance, ­agents ­able to dis­tin­guish ­between infec­tive and non-infec­tive ­causes of inflam­ma­tion.