Territorial arterial spin labeling in the assessment of collateral circulation: comparison with digital subtraction angiography.
OBJECTIVE
Collateral circulation plays a vital role in patients with steno-occlusive disease, in particular for predicting stroke outcome. Digital subtraction angiography (DSA) is the gold standard for the assessment of collateral circulation, despite its invasive nature. Recently, the development of a new class of arterial spin labeling (ASL) methods allowed independent measurement of territorial flow information without the need for contrast media injection. Here, we compared combined territorial ASL (TASL) and MR angiography (MRA) against DSA in the assessment of collateral circulation.


METHODS
Eighteen patients presenting with extra- or intracranial arterial steno-occlusive disease were recruited. All DSA studies were performed using a biplane angiography unit. MR imaging consisted of time-of-flight MRA and TASL, performed at 3T. Collateral circulation on both modalities was evaluated in consensus in a double-blinded manner by 3 neuroradiologists.


RESULTS
Good agreement was found between DSA and TASL in the assessment of collateral flow: Cramer coefficient, V=0.53 (P<0.0001) and Contingency coefficient, C=0.67, with kappa=0.70 and kappa=0.72 in the assessment of flow and collaterals, respectively. TASL and DSA successfully evaluated 89% and 98% of the vessels, respectfully. Failure was linked to motion-related artifacts in TASL, and highly tortuous vessels in DSA. Generally, combined MRA-TASL was comparable to DSA in diagnostic quality.


CONCLUSIONS
TASL provided radiological information comparable to DSA on collateral flow, with the advantage that it could be performed during routine MRI studies. TASL may provide insight on collateral perfusion in patients who may not otherwise be candidates for DSA, and may potentially replace it.
Department of Neuroradiology, National Neuroscience Institute, Singapore.
Soke Miang
SM
Chng
Esben Thade
ET
Petersen
Ivan
I
Zimine
Yih-Yian
YY
Sitoh
C C Tchoyoson
CC
Lim
Xavier
X
Golay
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D016477:Artifacts; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000503:physiopathology; D016893:Carotid Stenosis / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D002544:Cerebral Infarction / Q000209:etiology; D002560:Cerebrovascular Circulation; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003097:Collateral Circulation; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000209:etiology; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009038:Motion; D011237:Predictive Value of Tests; D013113:Spin Labels
D013113:Spin Labels