Article Figures & Data
Figures
- Fig 1.
Hypothetic workflow of importing 4D-DSA into the treatment plan computer (Advanced Leksell GammaPlan Program; Elekta) and the workflow of the current practice. Application of the stereotactic frame to the patient's skull and measurement of skull geometry are performed first in the preparation room.
- Fig 2.
A, Early opacification phases of the AVM nidus, where only the feeding artery and a portion of the nidus are opacified. B, Middle opacification phases of the AVM nidus, in which both the feeding artery and nidus are opacified, as well as a portion of draining vein. This phase is optimal for nidus delineation. C, In the late opacification phase, the draining veins are completely opacified and may obstruct the visibility of the nidus.
- Fig 3.
A, 4D-DSA of a 53-year-old man with a larger and more intricate AVM. The red arrow indicates a non-nidus territory, where it is considered part of AVM nidus based on the integrated MR images, enclosed within the irradiated volume. B, The corresponding TOF-MR imaging section. C, The T1-weighted MR image is shown on the same axial location. The nidus territory depicted by T1-weighted imaging is blurred. D, The T2-weighted MR image is shown on the same axial location. The T2-weighted MR imaging section provides clearer depiction of the nidus territory than the T1-weighted MR imaging because it does not show a flow void in the region in question.
- Fig 4.
A, A 4D-DSA section of a 41-year-old man with a left sigmoid DAVF. The 4D-DSA provides opacification of the fistula. However, the central portion is empty. This feature may be attributed to technical difficulties or improper selection of an optimal frame. B, TOF-MR imaging of the same patient. TOF-MR imaging shows clear opacification of the fistula. C, The T1-weighted MR imaging section. The fistula is completely invisible; thus, the T1-weighted MR imaging is incapable of defining the fistula. D, T2-weighted MR imaging section. Defining the fistula is not feasible due to its invisibility on T2-weighted MR imaging as well.
- Fig 5.
A, 3D rendering of contoured AVM volumes in Matlab. The semitransparent blue shell is the volume contoured by using integrated stereotactic imaging, whereas the solid red mesh depicts the volume contoured on 4D-DSA. Generally, the contoured volume of 4D-DSA is visually consistent with that of integrated stereotactic imaging. B, 3D rendering of contoured DAVF volumes in Matlab. The semitransparent blue shell is the volume contoured with integrated stereotactic imaging, whereas the solid green mesh depicts the volume contoured on 4D-DSA. Inconsistency between the 2 volumes is obvious.
- Fig 6.
A, A 4D-DSA section of a 55-year-old man with a large AVM that is supplied by 2 arterial territories, viewed from the posterior left viewpoint. A portion of the nidus is revealed by left vertebral artery injection. B, Another 4D-DSA volume is viewed from the same direction as in A. The remaining portion of the nidus is revealed by right internal carotid artery injection. C, The whole AVM nidus is shown by fusing 2 distinct volumes (the left vertebral artery portion is blue, with the right internal carotid artery portion being orange). Objective separation between distinct arterial territories can be done by using 4D-DSA with selective administration of contrast medium. The 2 volumes may then be fused to provide a panoramic view of the AVM nidus.
Tables
Volume comparison of AVM nidus and DAVF fistula between 4D-DSA and integrated stereotactic imaginga
Diagnosis 4D-DSA Volume (1st/2nd) (cm3) MR Imaging Volume (cm3) Conjoint Volume (1st/2nd) (cm3) Disjoint Volume (1st/2nd) (cm3) Volume Shown by 4D-DSA Only (1st/2nd) (cm3) Volume Shown by MR Imaging Only (1st/2nd) (cm3) DAVF 14.51/11.4 13.16 8.07/7.55 11.52/9.46 6.44/3.85 5.08/5.61 DAVF 2.92/3.26 5.09 1.9/2.02 4.21/4.31 1.02/1.23 3.19/3.07 DAVF 3.13/2.38 1.63 0.81/0.82 3.14/2.37 2.31/1.56 0.82/0.81 DAVF 3.29/2.98 4.34 2.82/2.56 1.98/2.19 1.98/0.41 1.51/1.77 DAVF 2.1/1.94 3.57 1.71/1.65 2.23/2.19 0.38/0.28 1.85/1.91 DAVF 4.98/4.74 4.89 4.14/3.81 1.59/2 0.84/0.92 0.74/1.07 DAVF 1.84/1.94 1.83 1.24/1.16 1.18/1.44 0.6/0.78 0.58/0.66 AVM 5.82/6.1 9.52 5.78/6.02 3.78/3.57 0.04/0.07 3.73/3.5 AVM 0.1/0.09 0.12 0.07/0.06 0.07/0.08 0.02/0.03 0.04/0.05 AVM 12.19/12.2 14.87 11.63/11.6 3.8/3.87 0.56/0.6 3.24/3.27 AVM 3.56/3.79 3.56 2.46/2.55 2.19/2.25 1.09/1.24 1.09/1.01 AVM 0.15/0.16 0.18 0.11/0.12 0.1/0.1 0.03/0.06 0.06/0.04 AVM 4.2/3.99 5.01 3.54/3.43 2.12/2.13 0.66/0.56 1.46/1.57 AVM 3.93/3.86 5.86 3.83/3.67 2.12/2.37 0.09/0.18 2.02/2.19 AVM 3.61/3.31 3.42 3.18/2.95 0.68/0.83 0.43/0.36 0.24/0.47 AVM 1.18/1.16 1.3 1.02/1.01 0.43/0.45 0.15/0.15 0.27/0.29 ↵a Target contouring on 4D-DSA was performed independently on Advanced Leksell GammaPlan Program by 2 physicians who were blinded to the MR images. In AVMs, the contoured volumes are smaller than those contoured on the basis of integrated stereotactic images. For DAVFs, the contouring on 4D-DSA was blocked; this outcome results in more prominent inconsistencies between volumes contoured on 4D-DSA and those of MR integrated stereotactic imaging.
