Magnetic Resonance Angiography in the Diagnosis of Cerebral Arteriovenous Malformation and Dural Arteriovenous Fistulas: Comparison of Time-Resolved Magnetic Resonance Angiography and Three Dimensional Time-of-Flight Magnetic Resonance Angiography

Abstract

Background: Traditional digital subtraction angiography (DSA) is currently the gold standard diagnostic method for the diagnosis and evaluation of cerebral arteriovenous malformation (AVM) and dural arteriovenous fistulas (dAVF).

Objectives: The aim of this study was to analyze different less invasive magnetic resonance angiography (MRA) images, time-resolved MRA (TR-MRA) and three-dimensional time-of-flight MRA (3D TOF MRA) to identify their diagnostic accuracy and to determine which approach is most similar to DSA.

Patients and methods: A total of 41 patients with AVM and dAVF at their initial evaluation or follow-up after treatment were recruited in this study. We applied time-resolved angiography using keyhole (4D-TRAK) MRA to perform TR-MRA and 3D TOF MRA examinations simultaneously followed by DSA, which was considered as a standard reference. Two experienced neuroradiologists reviewed the images to compare the diagnostic accuracy, arterial feeder and venous drainage between these two MRA images. Inter-observer agreement for different MRA images was assessed by Kappa coefficient and the differences of diagnostic accuracy between MRA images were evaluated by the Wilcoxon rank sum test.

Results: Almost all vascular lesions (92.68%) were correctly diagnosed using 4D-TRAK MRA. However, 3D TOF MRA only diagnosed 26 patients (63.41%) accurately. There were statistically significant differences regarding lesion diagnostic accuracy (P = 0.008) and venous drainage identification (P < 0.0001) between 4D-TRAK MRA and 3D TOF MRA. The results indicate that 4D-TRAK MRA is superior to 3D TOF MRA in the assessment of lesions.

Conclusion: Compared with 3D TOF MRA, 4D-TRAK MRA proved to be a more reliable screening modality and follow-up method for the diagnosis of cerebral AVM and dAVF.

Keywords: 3D TOF MRA; 4D-TRAK MRA; Cerebral Arteriovenous Malformation; Cerebral Dural Arteriovenous Fistulas.

Figure 1.. A 47-year-old man with a small AVM in the right lateral ventricle. A, Coronal TR-MRA shows the right lateral ventricle AVM with a nidus (arrow) supplied by a branch of the right anterior cerebral artery; B, Sagittal early; C, Late arterial; D, Venous phase TR-MRA images show the nidus (arrow) in the right lateral ventricle. Deep venous drainage occurs via an internal cerebral vein (arrow head) in the straight sinus.

Figure 2.. DSA examination of the AVM shown in Figure 1. A, Corresponding anteroposterior projection of injection into the right internal carotid artery, showing an AVM nidus (arrow) supplied by a branch of the right anterior cerebral artery; B, Early; and C, Late arterial; D, Venous phase lateral projections show the AVM nidus (arrow) and deep venous drainage occurs via an internal cerebral vein (arrow head) in the straight sinus.

Figure 3.. 3D TOF MRA of the AVM shown in Figure 1. A, Coronal; B, Sagittal views show no AVM nidus can be identified due to lack of venous phase information. A high signal intensity (arrow) resulting from flow artifacts of the great cerebral vein might be misdiagnosed as a vascular lesion.

Figure 4.. A 38-year-old man with right parietal lobe AVM. A, Coronal TR-MRA shows the right parietal AVM with a nidus (arrow) supplied by branches deriving from the right anterior and middle cerebral arteries; B, Sagittal early; C, Late arterial; D, Venous phase TR-MRA images show the AVM nidus (arrow) in the right parietal lobe. Superficial and venous drainage occurs via a dilated cortical vein in the superior sagittal sinus (arrow head).

Figure 5.. DSA examination of the AVM shown in Figure 4. A, The AVM is confirmed by the anteroposterior projection upon injection into the right internal carotid artery, which shows a vascular nidus (arrow) supplied by branches deriving from the right anterior and middle cerebral arteries. B, Early C, Late arterial; D, Venous phase lateral projections show the AVM nidus (arrow) and venous drainage occurs via a dilated cortical vein in the superior sagittal sinus (arrow head).

Figure 6.. 3D TOF MRA of the AVM shown in Figure 4. A, Coronal; B, Sagittal views also reveal a focal hyperintense nidus (arrow) in the right parietal region supplied by branches deriving from right anterior and middle cerebral arteries. However, the venous drainage cannot be confirmed due to lack of venous phase information. In addition, a high signal intensity (arrow head) resulting from flow artifacts of the great cerebral vein is visualized.