Advances in Spinal Cord MR Angiography

Abstract

SUMMARY:Novel developments in MR angiography are reviewed that enable non-invasive clinical imaging of normal and abnormal vessels of the spinal cord. Current fast contrast-enhanced MR techniques are able 1) to visualize vessels supplying or draining the spinal cord and 2) to differentiate spinal cord arteries from veins. The localization of the Adamkiewicz artery, the largest artery supplying the thoracolumbar spinal cord, has become possible in a reproducible and reliable manner. Knowledge of the anatomic location of this artery and its arterial supplier may be of benefit in the work-up for aortic aneurysm surgery to reduce incidences of ischemic injury. Spinal cord MR angiography is ready to become a diagnostic tool that can compete with catheter angiography for detecting and localizing arterial feeders of vascular lesions and is strongly advised for use prior to invasive catheter angiography. Successful clinical application strongly relies on in depth knowledge of the complex spinal cord vasculature and skills in image postprocessing. Due to their small calibers, clinical imaging of spinal cord arteries and veins was until recently only possible using catheter angiography. MR imaging by virtue of its strong soft tissue contrast is widely applied in patients suspected of harboring spinal vascular abnormalities. Using MR imaging in these patients, the diagnosis was predominantly based on changes of the cord tissue appearance but not on direct visualization of abnormal vessels.1 Even today it is beyond doubt that catheter angiography is the ultimate imaging technique for diagnosing, localizing, and classifying spinal vascular lesions.2 Despite its superior spatial resolution and image quality, it has, however, several major drawbacks, because it is invasive, involves exposure to ionizing radiation, and has a small risk for major complications.3,4 Furthermore, it is time consuming, may require a number of diagnostic sessions, and can only be performed by experts. Moreover, catheter angiography can be difficult to perform in patients with aortic diseases, such as aortic aneurysms.4,5 For these reasons, new developments in spinal cord angiography were prompted.It was mainly from clinical research in aortic aneurysm surgery that the request came to develop noninvasive visualization of normal arteries supplying the spinal cord to avoid the risk of paraplegia induced by interruption or damaging of the spinal cord blood supply. Catheter angiography is regarded as especially unattractive, because it is relatively hazardous in these patients due to the potential dislocation of aortic thrombi and because its sensitivity in detection of the main arterial supplier of the thoracolumbar spinal cord, that is, the Adamkiewicz artery (AKA), is too variable and too low (43%-86% 4-6 ). Traditional MR angiographic techniques before 2000 were not able to depict normal intradural arteries and were restricted to the visualization of pathologically dilated arteries and veins.7 Recent advances in MR and CT angiography were first demons...

Computed tomographic angiography of anterior spinal artery in acute cervical spinal cord injury

“…MRA is beneficial for the visualization of submillimeter-to-millimeter-sized intradural vessels and helpful for indicating the location of the vascular lesion. 4 We hypothesize that spinal cord ischemia may result in ASA rupture in acute traumatic SCI. We also hypothesize that CTA of ASA is the ideal method of covisualizing both ASA and injured bones.…”

Spinal Dural Fistulas without Swelling and Edema of the Cord as Incidental Findings

“…[1][2][3][4] MR imaging typically shows a triad of dilated perimedullary veins, cord swelling, and central high signal intensities on T2-weighted images. [5][6][7] In recent years, we discovered that not all SDAVFs present with spinal cord signal abnormality and cord swelling and that SDAVFs may be encountered as incidental findings on imaging studies for unrelated symptoms. In a 10-year period from 2001 to 2011, we encountered 52 patients with SDAVFs in our hospital, and 5 of these (10%) were asymptomatic and incidentally discovered.…”

Technical Advancements and Utilization of Spine Surgery -International Disparities in Trend-Dynamics Between Japan, Korea, and the USA

“…25,36) High magnetic field MRI (1.5 T to 3 T) and new pulse sequences 47,61) and image processing based on three-dimensional (3D) sampling allow better delineation of the roots or radiculomedullary vasculature in addition to the cord. 6,40,57) These imaging techniques are immediately applicable to daily practices. MPR can show the nerve root outside the common dural sac.…”

“…The advent of high magnetic field MRI 6,31,66) and multi-detector CT with capability of helical or spiral scanning, 14) and subsequent development of computer processing of the data such as multiplanar reconstructions (MPR) or maximum intensity projections, 25,36,40,59) enhanced enormously the amount and the availability of information we obtain from neuroimaging studies. This has provided hitherto unavailable insights regarding the pathological processes taking place inside the spinal cord and the nerve roots.…”