Time-resolved MR angiography of the intracranial venous system: an alternative MR venography technique.

OBJECTIVES: To compare time-resolved imaging of contrast kinetics (TRICKS) magnetic resonance angiography (MRA) with two-dimensional time-of-flight (TOF) magnetic resonance venography (MRV), and three-dimensional contrast-enhanced (CE) MRV in the visualisation of normal cerebral veins and dural venous sinuses.
METHODS: This prospective study consisted of 35 consecutive patients. All patients were examined with TOF MRV, TRICKS MRA and CE MRV; a single dose of intravenous contrast material was administered for the last two sequences. The image quality of these techniques was assessed and compared qualitatively (by a semiquantitative scoring system) and quantitatively (by calculating signal-to-noise ratios [SNRs] and contrast-to-noise ratios [CNRs]).
RESULTS: Left transverse sinus, left sigmoid sinus, bilateral thalamostriate veins and Trolard veins were better visualised by TRICKS MRA and CE MRV compared with TOF MRV (P < 0.05). For left thalamostriate vein visualisation, TRICKS MRA was inferior to CE MRV (P < 0.05). With quantitative analysis the SNRs and CNRs were highest at TRICKS MRA, which was followed by CE MRV and TOF MRV (P < 0.05).
CONCLUSIONS: Despite its limited spatial resolution, TRICKS MRA is comparable to static CE MRV and better than TOF MRV in the visualisation of normal dural sinuses and cerebral veins. KEY POINTS: • Time resolved magnetic resonance angiography can image the intracranial venous system dynamically • It seems comparable to contrast-enhanced MRV techniques in venous visualisation • The optimal phase for venous structures can be chosen from the dynamic data set • The diagnostic performance in venous thrombosis requires further research.