Introduction: Our preliminary study demonstrates that dMRA with Radial-TrueSTAR provides shorter scan time (up to 3 fold) while preserving similar image qualities compared to dMRA with Cartesian-TrueSTAR2. In the present study, we investigated the clinical utilities of Radial-TrueSTAR dMRA in patients with various cerebrovascular diseases, by comparison with time of- flight (TOF) and DSA.

Methods: Eleven patients with cerebrovascular diseases, including eight arteriovascular malmormation (AVM), two arteriovascular fistular (AVF) and one cerebral aneurysm were enrolled in this study. 4-D MRA images were acquired from each patient using Radial-TrueSTAR. To fully cover the draining veins, two slabs were acquired in some AVM cases. TOF images were also collected from each subject. DSA was also performed in some patients for follow-up. Spetzler–Martin grading scale was evaluated in AVM patients with 4-D dMRA, TOF, dMRA plus TOF and DSA respectively by two neuroradiologists. Diagnostic confidence scores for three components of AVMs (feeding artery, nidus and draining vein) were graded from 1 (poor imaging quality with severe artifacts and no diagnostic value) to 5 (excellent imaging quality with no artifacts and definite diagnosis).

Results: AVM lesions were detected in 6/8 patients on DSA (Table 1). The delineation of AVM lesions using TrueSTAR is consistent with that of DSA (Figure 1), except dMRA failed to detect one small lesion (6mm) with low blood flow which was manifested as lightly stained on DSA. DMRA had the same Spetzler–Martin grading scales in terms of AVM size and location but failed to detect deep draining veins in 2 patients. Compared to TOF, the heterogeneity within the nidus can be observed using Radial-TrueSTAR (Figure 1). Improved diagnostic accuracy was achieved when dMRA and TOF MRA are combined (Table2). Two AVF and one aneurysm were also detected on dMRA clearly (Figure 2).

Conclusions: Radial-TrueSTAR may become a promising approach with reduced scan time and patient comfort in clinical applications.

Patient Care: This technique may be useful in the clinical evaluation of cerebrovascular diseases noninvasively.

Learning Objectives: Non-contrast 4-D dMRA can be used for the evaluation of hemodynamics in cerebrovascular diseases.

References: 1. Yan L, Wang S, Zhuo Y, et al. Unenhanced dynamic MR angiography: high spatial and temporal resolution by using true FISP-based spin tagging with alternating radiofrequency. Radiology. 2010; 256: 270-9. 2. Zhou Z, Han F, Yu S, et al. Accelerated noncontrast-enhanced 4-dimensional intracranial MR angiography using golden-angle stack-of-stars trajectory and compressed sensing with magnitude subtraction. Magn Reson Med. 2017. 3. Yu S, Yan L, Yao Y, et al. Noncontrast dynamic MRA in intracranial arteriovenous malformation (AVM), comparison with time of flight (TOF) and digital subtraction angiography (DSA). Magn Reson Imaging. 2012; 30: 869-77.