Time-resolved contrast-enhanced magnetic resonance angiography in the investigation of suspected intracranial dural arteriovenous fistula

Abstract

Cerebral angiography is widely regarded as the gold standard for the evaluation and diagnosis of neurovascular abnormalities. However, recent improvements in the spatial and temporal resolution of time-resolved magnetic resonance angiography (MRA) offer clinicians a non-invasive alternative to cerebral angiography. We explored the utility of this technique in an elderly female patient with a suspected intracranial dural arteriovenous fistula (dAVF). A product pulse sequence available from the scanner's manufacturer (time-resolved imaging of contrast kinetics, TRICKS; GE Healthcare, Milwaukee, WI, USA) was used with the following parameters: TR/TE 2.832/TE 1.072 ms, flip angle 25°, receiver bandwidth 31.25 kHz, 0.75 NEX, acceleration factor (ASSET) of 2, field of view 14 cm, matrix size 96 × 96, phase-encoding left-right. Twenty overlapping 8-mm-thick slices were acquired in an axial orientation, with a slice spacing of 4mm. Images were acquired at 48 time points, with a temporal resolution of 0.3s/image. We found that all intracranial venous structures enhanced synchronously. There was no evidence of arteriovenous shunting. Retrograde venous flow explained the signal abnormality seen on time-of-flight MRA. We concluded that time-resolved MRA is useful in the investigation of suspected intracranial dAVF.