Comparison of Single- and Multi-Echo Susceptibility-Weighted Imaging in Detecting Cerebral Arteriovenous Shunts: A Preliminary Study

Abstract

Purpose: To compare the sensitivities of T2-weighted image (T2WI) and susceptibility-weighted imaging (SWI) in detecting cerebral arteriovenous fistula (AVF), cerebral arteriovenous malformation (AVM), and carotid-cavernous sinus fistula (CCF), and to qualitatively evaluate single-echo SWI (s-SWI) and multi-echo SWI (m-SWI) in characterizing vascular lesions.

Materials and methods: From January 2016 to December 2021, cerebral angiography-proven lesions were recruited. The sensitivities of T2WI and SWI in detecting vascular lesions were compared using McNemar's test. Qualitative evaluations of s-SWI and m-SWI were categorized to be of poor, average, or good quality and compared using Fisher's exact test.

Results: A total of 24 patients (mean age: 61 years, 12 female, and 12 male) were enrolled. Twenty patients underwent s-SWI or m-SWI, and four patients underwent both. AVF, AVM, and CCF were diagnosed in 10, 11, and 3 patients, respectively. SWI demonstrated higher sensitivity compared to that of T2WI (82.1% vs. 53.6%, p = 0.013). m-SWI showed better image quality compared to that of s-SWI (good quality, 83.3% vs. 25.0%, p = 0.009).

Conclusion: SWI demonstrated a higher sensitivity for detecting cerebral arteriovenous shunts compared to that of T2WI. m-SWI exhibited better image quality compared to that of s-SWI in characterizing vascular lesions.

Keywords: Angiography; Arteriovenous Fistula; Arteriovenous Malformation; Carotid-Cavernous Sinus Fistula; Magnetic Resonance Imaging.

Fig. 1. Study design.

TFCA-proven cerebral arteriovenous shunts from January 2016 to December 2021 were included in the study. Exclusion criteria were lack of validation by TFCA, 1.5T MRI, no T2WI, no SWI pulse sequences, and unavailability of pretreatment MRI. SWI = susceptibility weighted image, TFCA = transfemoral cerebral angiography, T2WI = T2-weighted image

Fig. 2. Features of SWI magnitude image of cerebral arteriovenous shunts.

A-F. SWI (A, C, E), TFCA (B, D, F). Representative cerebral arteriovenous shunt cases in SWI (A-C) validated using TFCA (D-F). (A) m-SWI demonstrates regional tortuous dilatation (arrow) of small veins, considered to be pseudophlebitic signs of an AVF. (B) TFCA demonstrates AVF with feeders from the bilateral middle meningeal arteries and distal branches of ACA. (C) s-SWI demonstrates a large AVM in the left frontal lobe with conglomeration of vessels and heterogeneous signals (arrow). (D) TFCA demonstrates AVM with multiple feeders from the ACA A1, left ACA A2, and left MCA. (E) s-SWI demonstrates bilateral CCF with increased signals at both the cavernous sinuses (arrows) and the distended right superior ophthalmic vein (arrowhead). (F) Selective angiography of the right internal carotid demonstrates CCF Barrow classification D draining into the ipsilateral superior ophthalmic vein and inferior petrosal sinus. ACA = anterior cerebral artery, AVF = arteriovenous fistula, AVM = arteriovenous malformation, CCF = carotid-cavernous sinus fistula, MCA = middle cerebral artery, m-SWI = multi-echo SWI, s-SWI = single-echo SWI, SWI = susceptibility weighted image, TFCA = transfemoral cerebral angiography

Fig. 3. Cerebral AVF detected by SWI magnitude image.

A-C. A 69-year-old male underwent (A) T2WI, (B) single-echo SWI, and (C) TFCA because of dizziness. (A) T2WI shows no AVF, while (B) single-echo SWI (average image quality) shows asymmetric distension and increased signals in the right sigmoid sinus (arrowheads) and suspicious dilated vessels in the right cerebellum (arrow). (C) Selective angiography of the right external carotid artery demonstrates Borden grade 1 AVF, with feeders from the right occipital artery draining directly into the ipsilateral sigmoid sinus. AVF = arteriovenous fistula, SWI = susceptibility-weighted image, TFCA = transfemoral cerebral angiography, T2WI = T2-weighted image

Fig. 4. Image-quality comparison of single- and multi-echo SWI in detecting cerebral AVM.

A-C. A 72-year-old female underwent (A) s-SWI, (B) m-SWI, and (C) TFCA because of motor weakness. (A) The s-SWI, classified as having average image quality, demonstrates slightly increased signals (arrow) in the left parietal and occipital lobes. (B) The m-SWI, classified as having good image quality, demonstrates much more conspicuous conglomeration of vessels with heterogeneous signals (arrow), suggestive of AVM. (C) TFCA confirms the 2.6 cm-AVM nidus (arrow), with main feeders from the left middle cerebral artery M4 draining into the cortical vein and vein of Trolard. AVM = arteriovenous malformation, m-SWI = multi-echo SWI, s-SWI = single-echo SWI, SWI = susceptibility-weighted image, TFCA = transfemoral cerebral angiography

Fig. 5. Comparison of image-quality of single- and multi-echo SWI in detecting cerebral AVF.

A-C. A 67-year-old male underwent (A) s-SWI, (B) m-SWI, and (C) TFCA because of headache. (A) The s-SWI, classified as having average image quality, demonstrates subtly dilated veins in the left temporal lobe (arrows). (B) The m-SWI, classified as having good image quality, demonstrates a much more conspicuous manifestation of regional dilatation of small veins (arrows) and petechial hemorrhage in the left temporal lobe. (C) TFCA confirms Borden grade 3 AVF, with feeders from the left occipital artery and middle meningeal artery draining into the transverse sinus. AVF = arteriovenous fistula, m-SWI = multi-echo SWI, s-SWI = single-echo SWI, SWI = susceptibility-weighted image, TFCA = transfemoral cerebral angiography