Investigation of zero echo time arterial spin labeling MR angiography in the follow-up of endovascular treatment of intracranial aneurysm

Abstract

Objective To investigate the value of zTE ASL MRA in the follow-up of interventional treatment of intracranial aneurysm at 1.5 T, using DSA as gold standard. Methods Patients with intracranial aneurysms who underwent coil embolization with or without stent were enrolled in this study. Both TOF MRA and zTE ASL MRA were performed on a 1.5T whole body scanner (MR360, GE, USA) equipped with an 8 channel head coil, and DSA was performed within one week of the MR examinations. Aneurysmal remnant and intra-stent opacity were analyzed. SE, PE, PPV, NPV of two MRA modalities in aneurysm recanalization detection were calculated. Kappa coefficient was used to determine the inter-reader and intra-reader reproducibility. Paired t test was used to test the visibility of in-stent lumen on two kinds of MRA. Results A total of 24 patients (27 aneurysms) were included in this study, 23 aneurysms were treated with stent assisted embolization, four coil embolization. Thirteen cases of aneurysm remnant were detected by DSA, 15 by zTE ASL and 11 by TOF MRA. zTE ASL MRA had a relatively higher SE (100%) and NPV(100%) as compared with TOF MRA. The Kappa value in identification of aneurysm remnant was 0.85 between zTE MRA and DSA and 0.70 between TOF MRA and DSA, respectively. The inter-reader reproducibility was good (Kappa 0.70), while the intra-reader reproducibility was excellent(Kappa 0.85). There was statistical significance in the scoring results of the in-stent lumen visibility. Conclusion zTE ASL MRA proved to be a better imaging modality as compared to TOF MRA to evaluate the endovascular treatment effectiveness of intracranial aneurysms, especially for assessing the aneurysmal recurrence and in-stent lumen visibility. Key words: Intracranial aneurysm; Radiology, interventional; Treatment outcome; Magnetic resonance imaging; Angiography, digital subtraction