Improvement of Shunt Detection with Arterial Spin-Labeling MR Imaging in Follow-Up of a Treated Cerebral Arteriovenous Malformation
Siriwan Piyapittayanan¹, Sarimon Wattanapituxpong¹, Chanon Ngamsombat¹, Thaweesak Aurboonyawat², Ekawut Chankaew², Janjira Petsuksiri³, Shuo Zhang⁴, Orasa Chawalparit¹
Affiliation : ¹ Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ² Division of Neurosurgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ³ Division of Radiation Oncology, Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ⁴ Philips Healthcare Germany, Health Systems, Clinical Science, Hamburg, Germany
Objective: To identify and evaluate the pitfalls of using arterial spin labeling (ASL) to diagnose cerebral arteriovenous malformation (AVM) and improve its accuracy in clinical practice.
Materials and Methods: A retrospective study of 54 patients with cerebral AVM was performed. Each patient underwent magnetic resonance imaging (MRI) studies, including pseudo-continuous ASL (pCASL) and conventional cerebral angiography with a digital subtraction angiography (DSA) during a 3-year period. The consensus of the results of the imaging studies was used to evaluate the diagnostic performance of the MRI technique, with DSA used as the gold standard.
Results: Diagnostic accuracy was 94.4% when a positive arteriovenous shunt (AVS) was defined as a high ASL signal in the venous structure or nidus, compared to magnetic resonance angiography (MRA). The misinterpretations of the ASL images of cerebral AVM were due to an arterial transit artifact (ATA) associated with a residual AVS. The other pitfalls were micro-AVMs and very slow-flow AVSs.
Conclusion: To improve the accuracy of ASL in evaluating an AVS in cerebral AVM, it is mandatory to detect high ASL signals in venous structures by comparing with MRA.
Received 30 August 2021 | Revised 23 November 2021 | Accepted 23 November 2021
DOI: 10.35755/jmedassocthai.2022.03.13276
Keywords : Arterial spin labeling; Arteriovenous malformation; Arteriovenous shunt; Magnetic resonance angiography
