A segmentation-independent volume rendering visualisation method might reduce redundant explorations and post-surgical complications of microvascular decompression.

OBJECTIVES: This study aimed to investigate the feasibility of segmentation-independent volume rendering (SI-VR) in visualising the root entry zone (REZ), and to explore the influence on the management of vascular compression syndromes (VCSs).

METHODS: Two hundred and twenty patients with VCSs were recruited in this prospective study from July 2015 to May 2019. SI-VR was reconstructed based on inverted 3D fast spin echo T2WI. They were assigned to the experimental group and control group randomly. Patients in the experimental group would accept extra evaluation based on SI-VR before microvascular decompression. Image quality and diagnostic accuracy between SI-VR and 3D fast spin echo T2WI in the experimental group were compared by Mann-Whitney U test and chi-square test, separately. Interobserver agreement was performed with intraclass correlation coefficient. Postsurgical outcomes and complications between two groups were compared by chi-square test.

RESULTS: SI-VR had a better interobserver agreement (0.82 vs 0.68) and diagnostic accuracy (95.5% vs 83.6%, p = 0.004) than that of 3D fast spin echo T2WI. Especially, significantly improved diagnostic accuracy was reached in detecting the multi-vascular branches compression (100% vs 15.4%, p < 0.001). There were fewer complications (7.1% vs 26.8%, p = 0.004) and less operation time (20.7 min vs 14.5 min, p = 0.007) but no significant difference of pain relief (p = 0.19) in the experimental group than in the control group.

CONCLUSIONS: The SI-VR method is feasible for the precise demonstration of the anatomy structure along the REZ, with high reliability and reproducibility. Unbiased pre-surgical visualisation could reduce redundant explorations and post-surgical complications in patients who undergo microvascular decompression.

KEY POINTS: • Visualisation of the root entry zone by the segmentation-independent volume rendering is in accordance with the landscape by the neuro-endoscopy. • Segmentation-independent volume rendering has an advantage over 3D fast spin echo T2WI in the visualisation of multi-vascular branches compression. • Presurgical 3D visualisation of the neurovascular compression at the root entry zone leads to less postsurgical complications from the decrease of redundant exploration.