MR Steal Phenomenon Corresponds to Cerebral Angiogram Circulation Time

ABSTRACT Background Cerebrovascular reserve (CVR) is crucial for assessing hemodynamic impairment in patients with cerebrovascular steno‐occlusive disease. Although catheter cerebral angiography is the gold standard for evaluating CVR and collateral circulation, acetazolamide‐challenged arterial spin labeling perfusion MRI (AC‐ASL) emerged as a non‐invasive alternative, but its effectiveness in reflecting neuroangiographic parameters is not fully understood. Methods A retrospective study was conducted on patients who underwent AC‐ASL from 2014–2022. Patients were excluded if concurrent angiographic analysis was not performed, or image quality was compromised. The study involved correlating cerebral angiographic metrics like arteriocapillary circulation time (ACCT) and superior sagittal sinus entry (SSSE) with AC‐ASL flow parameters in patients with steno‐occlusive disease. MR acquisitions were obtained prior to acetazolamide administration and after 1 g of acetazolamide administered at 5‐ and 10‐min intervals. Cerebral angiography was performed via a transfemoral approach utilizing a dual‐plane digital subtraction angiogram (DSA) radiographic angiographic system. CT angiograms were utilized if DSA was not available. Results The study included 32 patients, predominantly with unilateral disease. A significant correlation was found between AC‐ASL adjusted steal percent and angiographic ACCT ( ρ = −0.386, p = 0.035), which was stronger when comparing the ratio of ACCT (rACCT) between occlusive and nonocclusive hemispheres ( ρ = −0.4680, p = 0.008). No significant correlation was found between AC‐ASL and SSSE nor angiographic collateralization patterns. Conclusion AC‐ASL correlates with ACCT, comparable to catheter angiography in patients with steno‐occlusive disease, with a weak‐moderate coefficient. AC‐ASL may be useful for the assessment of CVR in patients, providing a safe and non‐invasive adjunct to assessing CVR.