Hooman Yarmohammadi MD, Presenter: Nothing to Disclose

Daniel Pierce Hsu MD, Abstract Co-Author: Nothing to Disclose

Nelly Salem MD, Abstract Co-Author: Nothing to Disclose

Shakeel Chowdhry MD, Abstract Co-Author: Nothing to Disclose

Jitendra Sharma, Abstract Co-Author: Nothing to Disclose

Robert W. Tarr MD, Abstract Co-Author: Nothing to Disclose

Jeffrey Lloyd Sunshine MD, PhD, Abstract Co-Author: Nothing to Disclose

Kristine Blackham MD, Abstract Co-Author: Nothing to Disclose

Digital subtraction angiography (DSA) is the established method for follow up evaluation of aneurysms after coiling. However, DSA is an invasive method with and therefore MR imaging has been suggested as an alternative. The aim of this study was to evaluate the diagnostic accuracy of contrast enhanced MRA (CE-MRA) and three dimensional time-of-flight (3D TOF) MRA in detecting post-coil residual aneurysm and compare the results to DSA.

286 patients with 302 intracranial aneurysms that were treated with detachable coils at our institution (from July 2006 through July 2011) were evaluated with 1.5T CE MRA (bolus triggered), 0.5 mm 3D TOF MRA, and 0.8 mm 3D TOF MRA. MRA studies were independently assessed by 4 neuroradiologist (DPH, SC, JS, and KB) blind to the DSA findings. All MRAs were performed in the 48-hour period post coil. MRA sequences were equivalent in all 286 patients. Data collected included demographic data (age, sex), size and location of the aneurysm, embolic material used, complications, residual flow in the neck of the aneurysm, residual flow in the coil mesh, aneurysm occlusion/patency and Raymond classification: complete obliteration, residual neck or residual aneurysm.

All patients had DSA images. Interobserver agreement was excellent for CE MRA (kappa =0.87), 0.5 mm 3D TOF (kappa =0.85), 0.8 mm TOF (kappa =0.80) and DSA (kappa =0.80). After reaching a consensus the DSA demonstrated 151 (50%) complete obliteration, 106 (35%) residual necks, 45 (15%) residual aneurysm. CE MRA was 98% specific and 99% sensitive in detecting residual aneurysm when compared to DSA. Considering visualization of residual aneurysm, CE MRA was significantly more accurate compared to 0.5 mm 3D TOF MRA and 0.8 mm 3D TOF MRA (p < 0.05).

To our best knowledge, this is the largest blinded study on comparing MRA technique for the evaluation of post-coil patients providing class I, level B evidence with a homogenous sample. CE-MRA appears to be superior to TOF MRA for visualization of residual patency with high degree of agreement with the DSA results. We conclude that CE-MRA can be used alone as an accurate method for follow-up imaging of post-coil aneurysms. Secondarily if patients can not receive contrast 0.8 3D TOF is an acceptable substitute.

CE MRA can be used alone as an accurate method for follow-up imaging of post-coil intracranial aneurysms.

Yarmohammadi, H, Hsu, D, Salem, N, Chowdhry, S, Sharma, J, Tarr, R, Sunshine, J, Blackham, K, Diagnostic Accuracy of Contrast-enhanced MR Angiography and Three-dimensional Time-of-Flight MR Angiography Compared to Digital Subtraction Angiography in Follow up Evaluation of Intracranial Aneurysms Treated with Coils and the Essential Sequences.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11015806.html