Arterial Spin-Labeling Perfusion for PHACE Syndrome

Abstract

Background and purpose: Arterial stroke is a rare-but-reported complication in patients with posterior fossa brain malformations, hemangiomas, arterial anomalies, coarctation of the aorta and cardiac defects, and eye abnormalities (PHACE) syndrome. Currently, stroke risk is inferred by the severity of arterial anomalies identified on MRA, though no evidenced-based data exist. The purpose of our study was to determine whether arterial spin-labeling MR imaging perfusion can detect alterations in CBF in patients with PHACE syndrome.

Materials and methods: Records were reviewed from 3 institutions for all patients with PHACE syndrome who underwent arterial spin-labeling from 2000 to 2019. CBF was qualitatively investigated with arterial spin-labeling to determine whether there was decreased or normal perfusion. Arterial anomalies were characterized on MRA imaging, and parenchymal brain findings were evaluated on conventional MR imaging sequences.

Results: Forty-one patients with PHACE syndrome had arterial spin-labeling imaging. There were 30 females and 11 males (age range, 7 days to 15 years). Of the 41 patients, 10 (24%) had decreased CBF signal corresponding to a major arterial territory. Ten of 10 patients had decreased CBF signal in the anterior circulation, 2/10 had decreased anterior and posterior circulation CBF signal, 2/10 had decreased bilateral anterior circulation CBF signal, and 1/10 had globally decreased CBF signal. Forty of 41 (97.5%) patients had at least 1 arteriopathy, and in those with decreased CBF signal, the arteriopathy corresponded to the CBF signal alteration in 10/10 patients.

Conclusions: Arterial spin-labeling can potentially characterize hemodynamic changes in patients with PHACE syndrome.

FIG 1.

Decreased CBF in PHACE syndrome. A, Axial T2-weighted fat-suppressed image shows a left periorbital hemangioma. B, Axial time-of-flight MRA shows absence of the left cavernous ICA (arrow), which was reconstituted on the relatively more superior images (not shown). C, Axial ASL imaging shows decreased CBF signal in the left ICA territory (arrows).

FIG 2.

Decreased CBF in PHACE syndrome. A, Axial T1-weighted contrast-enhanced fat-suppressed image shows hemangiomas in the left frontoparietal scalp. B, Axial time-of-flight MRA shows a hypoplastic left cavernous ICA (arrow). C, Axial ASL imaging shows decreased CBF signal in the left ICA territory (arrows). The scalp hemangiomas show hyperintense signal (arrowheads) due to their arterial vascularity.

FIG 3.

Normal CBF signal in PHACE syndrome. A, Time-of-flight MRA reconstruction shows absence of the right cervical and intracranial ICA (arrow). The right A1 anterior cerebral artery segment is also absent (arrowhead). B, Axial ASL imaging shows symmetric CBF bilaterally. This case shows that despite a severe arteriopathy, ASL provides additional value by showing normal CBF signal.