Evaluation of lower back pain with bone scintigraphy and SPECT

Bone scintigraphy and single photon emission computed tomography (SPECT) ma y be performed for evaluation of lower back pain, especially when a bone ab normality is suspected. Various patterns of tracer activity based on precis e identification of the anatomic location of increased uptake may be observ ed and used to evaluate bones and joints, Lesions centered about the disk s pace and vertebral body include spondylodiskitis, metastatic disease, verte bral body fracture, and degenerative disease (disk disease, spondylosis def ormans). In diskitis, tracer uptake has a vertical orientation. Metastatic involvement should be suspected in solitary lesions evaluated with SPECT wh en the area of increased uptake extends from the vertebral body into the pe dicle, Fractures are seen on planar and SPECT images as a linear, horizonta lly oriented area of increased uptake centered in the vertebral body, In de generative disease, increased uptake is centered about the disk space and m ay be seen in and project beyond the surface of the vertebral body. Lesions of the posterior arch (comprising the pedicle, lamina, and facet joints) i nclude spondylolysis, pedicle lesions, osteoarthritis of the facet joints, and fracture of the transverse process. Scintigraphy may help differentiate long-standing asymptomatic spondylolysis from ongoing disease, In osteoart hritis of the facet joints, SPECT may be used to select patients to be trea ted with therapeutic injections. Increased uptake in the transverse process most often indicates a fracture, although tumors may also occur in this lo cation, These findings at planar bone scintigraphy and SPECT allow differen tiation of common pathologic conditions and can lead to a specific diagnosi s.