Arjen Lindenholz

93 Comparison of 3T Intracranial Vessel Wall MRI Sequences 4 Qualitative assessment of both precontrast and postcontrast vessel wall images in multiple planes showed that in all subjects, the vessel wall could be delineated for both sequences ( Figure 5 ). Overall, variant 7 (4minutes 39 seconds) was slightly more affected by free induction decay (FID) artifacts in the outer regions of the FOV and slow-flow artifacts, but this did not affect the assessment of the large intracranial arteries. Inone subject, variant 7 (4minutes 39 seconds) showed small motion artifacts but they did not have an influence on the assessment. Sixteen vessel wall lesions were identified in variant 3 (6 minutes 42 seconds) and 19 in variant 7 (4 minutes 39 seconds). In 4 of 10 subjects, no vessel wall lesions were detected. Vessel wall lesions (on the basis of the 19 detected vessel wall lesions) were found in the carotid arteries ( n = 3), middle cerebral arteries ( n = 2), vertebral arteries ( n = 10), basilar artery ( n = 3) and posterior cerebral artery ( n = 1) of which 12 were enhancing (a full description of all lesions is found in Supplemental Table 3 ). All 16 lesions identified in vessel wall variant 3 (6 minutes 42 seconds) matched vessel wall lesions identified in variant 7 (4 minutes 39 seconds) ( Figure 5 ). One vessel wall lesion was reported as eccentric in variant 3 and concentric in variant 7, and 1 lesion, as enhancing in variant 3 and as non-enhancing in variant 7. Three lesions were missed with vessel wall variant 3; one lesion located at the bifurcation of the basilar artery – P1, one at the left internal carotid artery, and one at the left vertebral artery. Figure 5. Matching vessel wall lesions of the distal vertebral arteries (white arrowheads) seen before and after contrast with variant 3 (6:42min; A, B and C ) and variant 7 (4:39min; D, E and F ) in a 59-year-old man with multiple cardiovascular risk factors. Subtle (concentric) wall thickening is seen in both left and right vertebral arteries before contrast ( A and D ) with clear contrast enhancement on the postcontrast image ( B and E ). The variant 3 (6:42min, B and C ) was acquired approximately 2 minutes after contrast injection, and variant 7 (4:39min, E and F ) approximately 9 minutes after contrast injection. Some patient motion was seen for the postcontrast series of variant 7. Postcontrast transverse images of variant 3 ( C ) and variant 7 ( F ) show clear vessel wall enhancement in both vertebral arteries (white arrowheads).