The Usefulness of Lumbosacral Magnetic Resonance Imaging in the Management of Isolated Dysfunctional Elimination

Purpose: Magnetic resonance imaging is sometimes used to rule out spinal pathology in patients with dysfunctional elimination, although its usefulness in this setting is unclear. We determined the usefulness of magnetic resonance imaging in children with isolated dysfunctional elimination, and normal cutaneous, neurological and orthopedic examinations. Materials and Methods: We reviewed the records of children with dysfunctional elimination who underwent lumbosacral magnetic resonance imaging and identified those who were neurologically normal and who had normal cutaneous back examinations. Our primary goal was to determine the rate at which magnetic resonance imaging identified a spinal abnormality in this population. Univariate analysis was performed to assess the association of several clinical variables with a radiographic abnormality on magnetic resonance imaging. Results: Between 2000 and 2009 a total of 49 lumbosacral magnetic resonance imaging studies were performed in 29 females and 18 males with a mean age of 8.5 years (range 2.1 to 17). Four of the 49 imaging studies (8%) revealed a radiographic abnormality but in only 1 (2%) was clinically significant spinal pathology identified, that is filum lipoma causing cord tethering. Findings on the 3 remaining abnormal imaging studies were considered unrelated to bladder dysfunction. No clinical, demographic or videourodynamic findings were associated with a radiographic abnormality on magnetic resonance imaging. Conclusions: In children with isolated dysfunctional elimination complaints, and normal neurological, orthopedic and back examinations the diagnostic yield of lumbosacral magnetic resonance imaging is low but not zero. We suggest that spinal magnetic resonance imaging be used judiciously and as a test of last resort in these children.