Optimization of the Surgical Approach in AVMs Using MRI and 4D DSA Fusion Technique : A technical note

Previously published data demonstrated the possibility of displaying the angioarchitecture of intracranial vascular malformations using time-resolved 3D imaging (4D digital subtraction angiography [DSA]). The purpose of our study was to prove the technical feasibility of creating fused images of time-resolved 3D reconstructions and MPRAGE MRI data sets and to check the reliability of the correct anatomical display of the angioma nidus and the venous drainage in the fused images of patients with intracranial arteriovenous malformations (AVM).

In this study 20 patients with intracranial AVM underwent pretherapeutic DSA and time-resolved 3D DSA in addition to MRI including MPRAGE sequences. The images were post-processed with the fusion software tool on a dedicated research workstation. The fusion of both imaging modalities was done semi-automatically with automatic co-registration software followed by a manual co-registration.

Co-registered DSA/MRI data sets of 20 untreated AVMs were evaluated independently by two reviewers. Image fusion was successful in all 20 cases with an acceptable additional set-up time. The fused images were highly scored by the two raters in respect to their congruency of the dedicated regions. Precise anatomical localization of the nidus, the feeding arteries and the draining veins were possible with the merged images.

Creating fused images of time-resolved 3D DSA and contrast-enhanced T1-weighted MPRAGE MR images might be beneficial for the preoperative and intrasurgical workflow in patients with AVMs. This new software tool fulfils the required quality and accuracy of the merged images. The clinical validation has to be proven in further studies.