The Efficacy of Non-Invasive Radiological Modalities in the Assessment of Carotid Artery Stenosis and Occlusions

Purpose: The aim of the study was to determine the efficacy of different radiologic modalities in detecting and grading of extracranial carotid artery stenosis and occlusion. Materials and Methods: Thirty seven patients who were detected to have severe stenosis or occlusion by initial color doppler sonography (CDS) underwent both Time-offlight (TOF) and 3 dimensional contrast enhanced Magnetic Resonance Angiography (3D-CEMRA) examinations. In both MRA techniques anjiograms were constituted with the maximum intensity projection (MIP) algorithm from the source images. Twenty five of the patients underwent digital subtraction angiography (DSA). The degree of stenoses measured on the angiograms were classified as follows: mild (0-39%), moderate (40-69%), severe (70-99%), and complete occlusion. DSA findings were compared to findings obtained from CDS, TOF and 3D-CEMRA techniques. Results: A total of 100 cervical carotid segments (bilateral ICA and ECA segments in 25 patients) were evaluated. The correlation of DSA and 3D-CEMRA was perfect, as r value was 0.99 and kapa was 0.98; where they were 0.91 and 0.87 for TOF, and 0.98 and 0.95 for CDS, respectively. CDS misdiagnosed one patent segment as occluded and 2 moderate stenoses were overestimated as severe. In 8 segments the degree of stenoses were overestimated by TOF and one patent segment was identified as occluded. Except one patient that bolus timing was incorrect, all findings in 3D-CEMRA were correlated with angiography. Two distal ICA tandem lesions accompanying bifurcation stenoses were correctly identified by 3D-CEMRA and correlated with angiography. One ulcerated plaque was visualised by 3D-CEMRA, but not with TOF. Conclusion: According to our findings we conclude that for the correlation of CDS findings in the patients who are under consideration for carotid endarterectomy, the most reliable modality is 3D-CEMRA. If the findings obtained from CDS and 3D-CEMRA are concordant, angiography is unnecessary. ( Sakarya Med J 2016, 6(2):81-85 )