Vincent Maurice Timpone MD, Presenter: Nothing to Disclose

Sohil H. Patel MD, Abstract Co-Author: Nothing to Disclose

The imaging work up of a syrinx often includes contrast enhanced MR imaging to exclude the presence of an underlying mass lesion. The diagnostic yield of obtaining these additional contrast enhanced sequences is not well defined in the literature. We hypothesized that non-contrast T2WI sequences alone could reliably exclude the presence of an underlying syrinx associated lesion, without the need for additional contrast imaging.

We analyzed contrast enhanced MR scans of 87 consecutive patients with syrinxes over a 12 month period. The presence or absence of an associated spinal lesion was determined independently by 2 neuroradiologists using only sagittal and axial T2WI. Imaging features considered positive for a possible syrinx associated lesion on T2WI included cord signal abnormality separate from the syrinx, cord expansion, or complex syrinx septations/nodularity. Using contrast enhanced sequences as the reference standard, statistical analysis was subsequently performed to determine the accuracy of T2WI in detecting an associated spinal lesion.

Of the 87 patients, 49 were female and 38 male, with age range 2 – 77 years (median 43 years). Pathologies associated with the syrinxes included: 23 mass lesions, 11 Chiari malformations, 3 spinal cord contusions, and 50 idiopathic. Based on evaluation of each syrinx with T2WI alone, reader sensitivity for underlying mass lesion was 100%, specificity 83%, PPV 66%, NPV 100% (p<0.0001). Readers detected no findings suspicious for syrinx-associated mass lesion in 55/87 cases, and findings suspicious for mass lesion in 33/87 cases. Inter-reader agreement was excellent (kappa = 0.88).

Non-contrast MRI with sagittal and axial T2WI is an effective screening tool for the workup of a syrinx, and can reliably exclude the presence of an associated mass lesion. Post-contrast imaging may not be required in the majority of cases of spinal cord syrinx.  

In cases of syrinx, T2WI alone reliably excludes the presence of an underlying mass lesion. More judicious use of follow up contrast imaging may help save time and lower healthcare costs.

Timpone, V, Patel, S, MR Imaging of Syrinxes: Is Contrast Always Necessary?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007993.html