Prediction of MRI in intra-operative findings for spinal meningeal diseases

A large variety of spinal meningeal diseases have been described in the literature, and differential diagnosis is often complex, requiring a good knowledge of the different entities and accurate neuroimaging. The purpose of this article was to depict the most relevant diagnostic features on the commonly utilized MRI sequences for the main and most frequent pathologies of the spinal arachnoid and to correlate them with intraoperative findings.

Five cases harboring each different spinal meningeal diseases were analyzed, illustrated, extensively described, and discussed: arachnoid web, arachnoiditis, idiopathic spinal cord herniation, intradural arachnoid cyst, extradural arachnoid cyst. All the cases were surgically treated in the same institution (Neurological Hospital, Lyon, France). We underlined imaging clues for differential diagnosis to help physicians to elaborate the right diagnosis and guide the surgical management.

MRI was efficient to determine the nature of the arachnoid or/and dural disease as well as to predict precisely the intra-operative findings. Six key-radiological features were selected, helping differential diagnosis: localization (intra/extradural/both), aspect of the spinal cord (compressive effect/displacement/scalpel sign), arachnoid bride, CSF turbulent flow, vertebral scalloping, absence of gadolinium-enhancement.

MRI demonstrated excellent correlation with intra-operative findings for all the five spinal meningeal diseases analyzed. Although rare, these pathologies must be recognized by clinicians considering that appropriate treatment most often permit to relieve the symptoms.