Fig 1.
Pattern of the evaluation of registration results by overlapping the rDSA and the 3D-ioUS (rDSA rotational digital subtraction angiography, 3D-ioUS: intraoperative 3D-ultrasound, TN: true negative, FN: false negative, TP: true positive, FP: false positive).
Evaluation of registration; a.: preoperative rDSA; b.: preoperative 3D-ioUS; c.: intraoperative coregistration of a. and b.
Table 1.
Evaluation of 3D-ioUS.
Table 2.
Results of Dice-coefficient, Jaccard-Index and volume ratios for rDSA and 3D-ioUS volumes. (Due to incomplete aneurysm visualization or absent aneurysm in the field of view patients 6, 8, 9, 11, 13, 26 and 32 were excluded from calculations).
Fig 2.
Patient 17: The black arrow indicates M2 segment (temporal branch of MCA) of the medial cerebral artery, vasospasm of M2 segment visualized in post-clipping 3D-ioUS (E) which led to repositioning of the clip; (rDSA (red), 3D-ioUS (blue, orange); A: pre-clipping conventional DSA; B: pre-clipping rDSA; C: pre-clipping 3D-ioUS; D: post-clipping conventional DSA; E: post-clipping 3D-ioUS; F: coregistration of C+E.
Fig 3.
Patient 5: The yellow arrow indicates the aneurysm of the medial cerebral artery bifurcation; the black Arrow indicates the aneurysm origin/neck; improved visualization of the aneurysm neck in 3D-ioUS (B) with narrow M1 segment of the medial cerebral artery due to high blood flow velocity in bifurcation marked with a white arrow (D, E).; rDSA (red), 3D-ioUS (blue, glow-orange), A: pre-clipping rDSA; B: pre-clipping 3D-ioUS; C: coregistration of A+B; D: pre-clipping duplex; E: MIP 3D-ioUS; F: coregistration of A+E.
Fig 4.
Patient 30: The white arrows indicate the aneurysms of the medial cerebral artery bifurcation.
Contrary to rDSA (G; 2 aneurysms detected), 3 aneurysms were displayed in 3D-ioUS (H, J, K; 2 on MCA bifurcation and the 3rd aneurysm on M2 branch) as confirmed by the intraoperative view; (rDSA (red), 3D-ioUS (blue, glow- orange)); G: pre-clipping rDSA; H: pre-clipping 3D-ioUS; I: coregistration of G+H; J: MIP 3D-ioUS; K: MIP of 3D-ioUS; L: coregistration of K+H.
Fig 5.
Patient 29: Aneurysm of the medial cerebral artery bifurcation; the black and white arrows indicate the M2 segments of the medial cerebral artery; uncertainty in preoperative rDSA interpretation of M2 segment (single broad vessel vs. 2 nearby vessels); detection of 2 M2 branches (N, P and R) in 3D-ioUS as confirmed intraoperatively; rDSA (red), 3D-ioUS (blue, glow-orange); M: pre-clipping rDSA; N: pre-clipping 3D-ioUS; O: coregistration of M+N; P,Q: MIP of 3D-ioUS; R: coregistration of R+M.
Fig 6.
Patient 4: Aneurysm of the medial cerebral artery bifurcation indicated by the white arrow.
Precise aneurysm neck visualization in 3D-ioUS and clip segmentation for virtual planning of clipping procedure. A: pre-clipping rDSA (red); B: post- clipping rDSA (green); C: pre-clipping 3D-ioUS (blue); D: post-clipping 3D-ioUS (pink); E: post- clipping rDSA with segmented clips (red); F: post- clipping 3D-ioUS with segmented clips (red); G—H: coregistration of C+D; I: coregistration of A+C; J: coregistration of B+G.