Dynamic CT myelography: a technique for localizing high-flow spinal cerebrospinal fluid leaks

Abstract

In some patients with spontaneous spinal CSF leaks, leaks are numerous or tears are so large that extrathecal myelographic contrast material is seen at multiple levels during CT, making identification of their source impossible. This study introduces a dynamic CT myelographic technique that provides high temporal and spatial resolution. In this technical note, we describe the utility of this technique in four patients with challenging high-flow spinal CSF leaks.

Fig 1.

A 47-year-old man with a 4-year history of severe orthostatic headaches and tinnitus had documented low CSF opening pressures. Head MR imaging examinations showed diffuse pachymeningeal enhancement. Selected images from routine CT myelogram at the T5 (A), T6 (B), T7 (C), and T9 (D) interspaces demonstrate diffuse extrathecal contrast material (black arrows). The study lacks the temporal resolution necessary to locate the site of leak.

Fig 2.

Axial dynamic CT myelogram at the level of the T7–T8 interspace in the left lateral decubitus (A), right lateral decubitus (B), supine (C), and prone (D) positions demonstrates accumulation of extra-arachnoid contrast material along the ventral right aspect of the thecal sac, which increases in attenuation in the right lateral decubitus positioning (open arrows). The final prone images, which were obtained 30 minutes after injection of contrast, demonstrate dilution of contrast material in the previously unopacified epidural fluid collection and outlines the underlying T7 disk protrusion (black arrow)

Fig 3.

Axial dynamic CT myelogram at the level of the C7–T1 interspace in the left lateral decubitus (A), right lateral decubitus (B), supine (C), and prone (D) positions demonstrates accumulation of extra-arachnoid contrast material along the left C8 root sleeve (open arrow). The final prone images, which were obtained 30 minutes after injection of contrast material, demonstrate dilution of contrast material in the previously unopacified epidural fluid collection (black arrow). Additional leaks were located at the level of the right T6 root sleeve and along the ventral aspect of the junction of the right T9 root sleeve and thecal sac (not pictured).