The imaging diagnosis of nonpyogenic discitis in children.

Nonpyogenic discitis (NPD) is diagnosed on radiograms by the demonstration of the narrow disc-space with involvement of the adjacent vertebral bodies, and with radioisotope--by showing the increased uptake at the same level. Four phases are recognised in the development of the imaging changes. The isotope scan is important, especially in the latent phase of the disease when the radiograms are still negative. Radiologists are urged to consider the possibility of NPD in any child with vague abdominal, leg or back complaints whose origin cannot be ascertained. The experience of imaging diagnosis in five children is described and the differential diagnosis is discussed.