The clinical usefulness of radionuclide scintigraphy in suspected sacro-iliitis: a prospective study.

The ability of quantitative sacro-iliac scintigraphy (QSS) to detect sacro-iliac joint (SIJ) disease was compared to that of standard radiographs in a prospective study of 26 patients with low back pain suggestive of spondylitis. Of 52 SIJs studied, QSS was abnormal in 21 (40%) and radiographs positive in 23 (44%) (p = 0.47). QSS was abnormal in only 11 of the 23 (48%) radiographically abnormal SIJs. Conversely, 29 radiographically equivocal or negative SIJs yielded positive scintigraphs in ten (34%). Although QSS in general is no more sensitive than standard radiographs, it may allow detection of radiographically inapparent sacro-iliitis in carefully selected patients.