A 17-year-old female underwent an uncomplicated correction of scoliosis of the thoracic spinal column from T3 to T12 with screws and metal plates. Ten days after surgery, nausea and headache developed. Cerebrospinal fluid (CSF) hypotension syndrome and bacterial meningitis were excluded. Over the course of a year, periodic headache, increased CSF leucocytosis (with normal glucose) and raised erythrocyte sedimentation rate (ESR of 90 mm/h) persisted. Bacterial, viral and mycotic cultures of blood as well as CSF were negative. A chronic lymphocytic meningitis was diagnosed. No evidence was found for auto-immune disease or a medication effect, nor was a focus of infection identified. Cerebral and spinal cord functions remained undisturbed. Conventional X-ray (a) of the spinal column, ultrasound, whole-body FDG PET, gallium scintigraphy and bone scintigraphy all failed to identify the focus of infection. MRI was inconclusive owing to metal scatter caused by the screws and plates. Finally, 111mIn-DTPA SPECT cisternography was performed. A dose of 22 MBq of 111mIn-DTPA was injected intrathecally and acquisition was performed 4, 24 and 48 h after injection. On the SPECT acquisition two leakages were noticed, dorsally at the upper and the mid-thoracic level (b). An additional CT scan was fused with the 111mIn-DTPA SPECT scan and the leakages were located at the level of the third and sixth thoracic vertebrae (c). After this finding, the decision was made to remove the screws and metal plates, and to close the dura.

This case illustrates the additional value of fused 111mIn-DTPA SPECT-CT cisternography for more accurate localisation of CSF leakage. Further, fused SPECT-CT images can serve to update a long-existing nuclear imaging technique, in this case cisternography [1].