Usefulness of 3D T1-SPACE in Combination With 3D-TOF MRA for Follow-Up Evaluation of Intracranial Aneurysms Treated With Pipeline Embolization Devices

Abstract

Object: Follow-up evaluation of intracranial aneurysms treated by flow-diverting stents using MRI is challenging due to the presence of imaging artifacts. This study evaluated 3D T1-SPACE in combination with 3D-TOF sequence for follow-up evaluation of intracranial aneurysms treated with Pipeline embolization devices.Methods: Forty patients with 53 intracranial aneurysms who were treated with Pipeline Embolization Devices from October 2018 to July 2019 were enrolled in this study. All patients were evaluated for aneurysm occlusion and stent patency 4 to 7 months post-treatment using 3D T1-SPACE sequence, 3D-TOF MRA, and DSA examinations.Results: With regards to aneurysm occlusion, the intermodality (DSA and 3D-TOF MRA) agreement was good (κ = 0.755). The specificity of 3D-TOF MRA was 94.4% (34/36), the sensitivity was 76.5% (13/17), the total coincidence rate was 88.7% (47/53). With regards to the patency of the stented arteries after PED treatment, 3D T1-SPACE sequence was more accurate compared to 3D-TOF MRA (Z = −6.283, P < 0.001), with a no-artifact rate of 95.7% (44/46).Conclusions: 3D T1-SPACE sequence provides better image quality and higher accuracy for evaluating stented parent arteries compared to TOF-MRA. 3D-TOF MRA may be valuable in the evaluation of aneurysm occlusion. The combination of these two modalities may be used for long-term follow-up of intracranial aneurysms treated with Pipeline Embolization Devices.

Diagnostic Performance of High-Resolution Vessel Wall MR Imaging Combined with TOF-MRA in the Follow-up of Intracranial Vertebrobasilar Dissecting Aneurysms after Reconstructive Endovascular Treatment

“…This result was consistent with findings from a previous study demonstrating that 3D T1-weighted SPACE was more accurate than TOF-MRA in the assessment of patency of the stented artery in 53 intracranial aneurysms treated with the Pipeline. 13 In this study, regardless of whether the simplified 2-grade or 3-grade scale was used, the HR-VW-MR imaging had a 100% coincidence rate with DSA in the evaluation of the patency of the parent artery. Therefore, HR-VW-MR imaging is a good technique for assessing the patency of the parent artery in intracranial VBDAs treated with reconstructive EVT.…”

Intimal hyperplasia detection after aneurysm treatment by flow diversion using magnetic resonance vessel wall imaging

“…5,7 However, in the follow-up of intracranial stent-assisted coil embolization or flow diverter treated aneurysms, only few studies have so far analyzed the role of MR-VWI in evaluating instent patency. [8][9][10] In detail, in a prior study which evaluated stent-assisted coil embolization of intracranial aneurysms, MR-VWI was helpful in the identification of the 3 stenosis cases, providing similar results of DSA. 8 However, in this study, only baseline pre-contrast MR-VWI was performed, thus not allowing the possibility to evaluate vessel wall inflammatory changes.…”

“…An additional study, which analyzed intracranial aneurysms treated by FDS, compared MR-VWI performed with a 3D T1-SPACE sequence and TOF-MRA, demonstrating that MR-VWI provides better image quality and greater accuracy for evaluating stented parent arteries compared to TOF-MRA; all in-stent stenosis observed (5/46) were confirmed by DSA. 9 In a more recent study where a high-resolution MR-VWI sequence (scanning time: 11-13min) was performed in patients with intracranial aneurysms treated with FDS, focal mural enhancement of the parent vessel was commonly found in about 89% of patients. This observation suggests that focal mural enhancement can be considered an expected phenomenon in flow diverter therapy, related to reactive vessel wall inflammation.…”

“…An additional study, which analyzed intracranial aneurysms treated by FDS, compared MR-VWI performed with a 3D T1-SPACE sequence and TOF-MRA, demonstrating that MR-VWI provides better image quality and greater accuracy for evaluating stented parent arteries compared to TOF-MRA; all in-stent stenosis observed (5/46) were confirmed by DSA. 9…”

Recurrent reversible in-stent-stenosis after flow diverter treatment

“…However, a review of our own institutional follow-up routine showed that follow-up examinations of patients treated with FDS are rarely performed by DSA after more than 2 years but are usually performed by MRI. This might contribute to a low rate of detection since MRI with standard sequences has reduced specificity for stenosis in arterial segments treated by FDS [5].…”