Mean number and range of perforating branches per parent artery identified in the 7T postcontrast TOF-MRA images.

<p>^aIn one patient the posterior communicating artery was absent bilaterally.</p><p>^bOnly scans containing this segment within the FOV were taken into account.</p><p>Mean number and range of perforating branches per parent artery identified in the 7T postcontrast TOF-MRA images.</p

Typical images of intracranial perforators from different patients, obtained by postcontrast TOF-MRA at 7T.

<p>(A) A medial lenticulostriate artery (arrowhead), arising from the A1 segment of the ACA (transverse slab MIP, thickness 10mm), (B) lateral lenticulostriate arteries arising from the right MCA (arrows) and medial lenticulostriate arteries arising from the left ACA (arrowheads; coronal slab MIP, thickness 10 mm), (C) artery of Percheron (arrowheads), arising from the P1 segment of the PCA (coronal slab MIP, thickness 10mm), (D) perforating branch (arrowheads) arising from the right AChA (sagittal slab MIP, thickness 10mm), (E) thalamoperforating artery (arrowhead), arising from the left PCoA (transverse slab MIP, thickness 6mm), (F) pontine arteries (arrowheads) arising from the BA (transverse slab MIP, thickness 4mm), and (G) the intracranial feeders of the anterior spinal artery (arrows) with an adjacent vein (dashed arrow, transverse slab MIP angulated anterior-posterior in line with the BA, thickness 10mm). ACA = anterior cerebral artery; AChA = anterior choroidal artery; BA = basilar artery; ICA = intracranial carotid artery; MCA = middle cerebral artery; MIP = maximum intensity projection; PCA = posterior cerebral artery; PCoA = posterior communicating artery; P1 = first segment of the PCA; VA = vertebral artery.</p

7T TOF-MRA MIP images of different intracranial perforating arteries.

<p><b>On the left (A,C,E) the precontrast images with the corresponding postcontrast images of the same patient on the right (B,D,F)</b>. In B, D and F, longer arterial trajectories can be seen after contrast administration as compared to the corresponding unenhanced image in A, C and E (white boxes). (A and B) Sagittal slab MIP, thickness 10mm; (B and C) sagittal slab MIP, thickness 10mm; (E and F) coronal slab MIP, thickness 10mm. MIP = maximum intensity projection.</p

A 73-year-old female patient presented with subacute infarcts of the left parietal cortex and left internal borderzone area.

<p>(A) On the transverse 3D time-of-flight magnetic resonance angiography two stenoses can be appreciated, one in the left M1 segment of the middle cerebral artery (arrowhead) and one in M2 segment of the middle cerebral artery (arrow). The transverse T₁w VIRTA, after contrast administration, shows a corresponding vessel wall lesion in the M2 segment (B), this lesion is however missed by the transverse reconstruction of the sagittal T₁w VIRTA sequence, also after contrast administration (C) because of its limited field-of-view (indicated by the dashed lines in A).</p

Scan parameters of the acquired 3D sequences.

<p>Scan parameters of the acquired 3D sequences.</p

Patient demographics.

<p>Patient demographics.</p

Side-by-side comparison analysis of three different vessel wall sequences, relative to the sagitally reconstructed transverse T₁w VIRTA.

<p>Side-by-side comparison analysis of three different vessel wall sequences, relative to the sagitally reconstructed transverse T₁w VIRTA.</p

Proportions of raw agreement values for the four different sequences and three different measurements.

<p>Proportions of raw agreement values for the four different sequences and three different measurements.</p

Box plots of image quality, artifacts, and visibility of the plaque for the two raters.

<p>Red line = median value of rater 1, dashed red line = median value of rater 2, box = interquartile range, whiskers = minimum and maximum values, and rounds = outliers. The image quality and visibility of the plaque were scored on a scale from 0 (poor) to 2 (good); the presence of artifacts was scored on a scale from 0 (not present) to 2 (present with influence on diagnosis). Some whiskers are not visible because the lower quartile is equal to the minimum, or the upper quartile is equal to the maximum. Also, some median values overlap with the upper or lower quartile. The median value of the artifacts of the T₂w VIRTA is 0.5 because equal numbers are scored 0 and 1. Caps over the boxes represent significant differences, p-values for image quality, artifacts and visibility of the plaque were <0.001; <0.01; and <0.05, respectively, as assessed by repeated measures ANOVA and Sidak’s adjusted post hoc tests. As an example for the caps: in the upper panel there is an overall significant difference between the T₂w VIRTA and the PDw VIRTA (p<0.001).</p

Comparison between four different 3D intracranial vessel wall sequences at 3 tesla in a 47-year-old male patient presented with a bilateral partial anterior circulation infarct as caused by an occlusion and stenosis in the left and right middle cerebral artery (MCA), respectively.

<p>(A) On the transverse 3D time-of-flight magnetic resonance angiography two stenoses can be appreciated, one in the left M1 segment of the MCA and one in right M1 segment of the MCA (arrows). (B) Sagittal reconstruction of the transverse T₁w VIRTA, (C) sagittal T₁w VIRTA, (D) sagittal PDw and (E) sagittal T₂w images showing a vessel wall lesion in the left middle cerebral artery (arrows). On both T₁w VIRTA images and the PDw image the plaque can be clearly delineated, however on the T₂w image the vessel wall is less clear.</p