Preliminary study of 3D T1-SPACE combined with 3D-TOF MRA in the follow-up for the intracranial aneurysm treated with Pipeline Flex embolization device

Abstract

Objective To evaluate the preliminary application of three dimensional T1-weighted sampling perfection with application-optimized contrasts by using different flip angle evolutions (3D T1-SPACE) combined with three dimensional time-of-flight magnetic resonance angiography (3D-TOF MRA) in the follow-up for the intracranial aneurysm treated with Pipeline Flex embolization device (FD). Methods A total of 20 patients with 25 intracranial aneurysms were treated with Pipeline Flex embolization at the Department of Cerebrovascular Intervention, People′s Hospital of Zhengzhou University, Henan Provincial People′s Hospital from September 2018 to April 2019 and were prospectively enrolled. All patients were followed up with 3.0T 3D T1-SPACE sequence, 3D-TOF MRA and digital subtraction angiography (DSA) examination. O′kelly-Marotta (OKM) grading scale was used to evaluate the aneurysm residual and the four-point scale was used to evaluate the in-stent lumen visibility. Results The follow-up period for all patients was 6.0±0.8 months (range: 4-7 months). The OKM scale of all aneurysms evaluated by DSA indicated 18 patients with grade D, 2 patients with grade C and 5 patients with grade B. For aneurysms evaluated by 3D-TOF MRA combined with source image, the results showed grade D in 19 patients, C in 2 and B in 4. The overall concordance rate between 3D-TOF MRA and DSA was 88.0% (22/25). Taking DSA as standard(grade 4), the four-point scale of in-stent lumen of all 20 patients treated with 23 Pipeline Flex embolization devices and evaluated by 3D-TOF MRA indicated grade 3 in 16 stents, 2 in 6 and 1 in 1. No one showed the same as DSA results. However, grade 4 was revealed in 21 stents and 3 in 2 based on the evaluation by 3D T1-SPACE. The total concordance rate of 3D T1-SPACE and DSA was 91.3% (21/23). Conclusions Preliminary observations show that compared with DSA, 3D-TOF MRA could better assess the aneurysmal occlusion after FD treatment of intracranial aneurysms. The 3D T1-SPACE sequence shows the in-stent lumen clearly. The combination of the two sequences can be used for follow-up after FD treatment of intracranial aneurysms. Key words: Intracranial aneurysm; Magnetic resonance imaging; Follow-up study; Flow diverter device