CT Myelography: Clinical Indications and Imaging Findings

Abstract

CT myelography is an important imaging modality that combines the advantages of myelography and the high resolution of CT. It provides a detailed delineation of pathologic spine conditions, especially those involving the thecal sac and its contents. However, the role of CT myelography has dramatically and appropriately decreased with the advent of MRI, which provides a noninvasive method to demonstrate pathologic spine conditions with high signal intensity in soft tissues. At the present time, CT myelography is often performed in patients who require evaluation of the thecal sac but have a contraindication to undergoing MRI. However, there remain many situations in which CT myelography is indicated and plays a critical role in patient treatment. The authors review common and uncommon indications for CT myelography and demonstrate various pathologic conditions in which CT myelography plays a vital role in patient treatment in this modern era of MRI. © RSNA, 2020 • radiographics.rsna.org

Single- and Dual-Source CT Myelography: Comparison of Radiation Exposure and Establishment of Diagnostic Reference Levels

“…CT myelography (CTM) is a diagnostic CT examination with prior intrathecal contrast agent administration. CTM enables the evaluation of various spinal pathologies that contact, displace, or impinge the thecal sac, cord, or nerve roots [1][2][3]. It plays an important role in several indications such as intradural extramedullary cysts, spontaneous intracranial hypotension and postoperative cerebrospinal fluid (CSF) leaks, nerve root avulsion, spinal canal stenosis, arthritis, and other degenerative and meningeal conditions [2,3].…”

“…CTM enables the evaluation of various spinal pathologies that contact, displace, or impinge the thecal sac, cord, or nerve roots [1][2][3]. It plays an important role in several indications such as intradural extramedullary cysts, spontaneous intracranial hypotension and postoperative cerebrospinal fluid (CSF) leaks, nerve root avulsion, spinal canal stenosis, arthritis, and other degenerative and meningeal conditions [2,3]. Though the role of MRI for spinal diseases has increased continuously in recent decades due to its non-invasiveness and excellent soft tissue contrast, CTM is still indispensable, in particular when MRI is non-diagnostic or contraindicated [1,3,4].…”

“…Though the role of MRI for spinal diseases has increased continuously in recent decades due to its non-invasiveness and excellent soft tissue contrast, CTM is still indispensable, in particular when MRI is non-diagnostic or contraindicated [1,3,4]. Moreover, CTM offers advantages over MRI due to the possibility of dynamic imaging as well as different patient positioning [2,5]. In addition to the commonly used single-source CTM, examinations in dual-source mode may be useful to reduce artifacts, especially in patients with metal implants [6].…”

Myelography and the 20th Century Localization of Spinal Cord Lesions

“…The development of MR myelography – heavily T2-weighted imaging that enhances the contrast between the CSF-containing spinal canal and its surrounding structures – further stimulated this decline [30]. Even though MRI has now replaced CT myelography as the preferred imaging modality in diseases affecting the spinal cord, the procedure continues to be used in cases where MRI is contraindicated, particularly in the functional visualization of CSF leakage, spinal cord herniation, and spinal arachnoid cysts [1, 2].…”

“…In current clinical practice, MRI constitutes the predominant imaging modality for the diagnosis and localization of diseases affecting the spinal cord. In cases where MRI is contraindicated due to patient-related factors, the presence of an MRI-incompatible implanted devise, or expected significant artifacts, computed tomography (CT) myelography with intrathecal injection of contrast material continues to provide a useful alternative, particularly in the functional visualization of cerebrospinal fluid (CSF) leakage, spinal cord herniation, and spinal arachnoid cysts [1, 2].…”