PT  - JOURNAL ARTICLE
AU  - Lim, R.P.
AU  - Shapiro, M.
AU  - Wang, E.Y.
AU  - Law, M.
AU  - Babb, J.S.
AU  - Rueff, L.E.
AU  - Jacob, J.S.
AU  - Kim, S.
AU  - Carson, R.H.
AU  - Mulholland, T.P.
AU  - Laub, G.
AU  - Hecht, E.M.
TI  - 3D Time-Resolved MR Angiography (MRA) of the Carotid Arteries with Time-Resolved Imaging with Stochastic Trajectories: Comparison with 3D Contrast-Enhanced Bolus-Chase MRA and 3D Time-Of-Flight MRA
AID  - 10.3174/ajnr.A1252
DP  - 2008 Nov 01
TA  - American Journal of Neuroradiology
PG  - 1847--1854
VI  - 29
IP  - 10
4099  - http://www.ajnr.org/content/29/10/1847.short
4100  - http://www.ajnr.org/content/29/10/1847.full
SO  - Am. J. Neuroradiol.2008 Nov 01; 29
AB  - BACKGROUND AND PURPOSE: Time-resolved MR angiography (MRA) offers the combined advantage of large anatomic coverage and hemodynamic flow information. We applied parallel imaging and time-resolved imaging with stochastic trajectories (TWIST), which uses a spiral trajectory to undersample k-space, to perform time-resolved MRA of the extracranial internal carotid arteries and compare it to time-of-flight (TOF) and high-resolution contrast-enhanced (HR) MRA.MATERIALS AND METHODS: A retrospective review of 31 patients who underwent carotid MRA at 1.5T using TOF, time-resolved and HR MRA was performed. Images were evaluated for the presence and degree of ICA stenosis, reader confidence, and number of pure arterial frames attained with the TWIST technique.RESULTS: With a consensus interpretation of all sequences as the reference standard, accuracy for identifying stenosis was 90.3% for TWIST MRA, compared with 96.0% and 88.7% for HR MRA and TOF MRA, respectively. HR MRA was significantly more accurate than the other techniques (P < .05). TWIST MRA yielded datasets with high in-plane spatial resolution and distinct arterial and venous phases. It provided dynamic information not otherwise available. Mean diagnostic confidence was satisfactory or greater for TWIST in all patients.CONCLUSION: The TWIST technique consistently obtained pure arterial phase images while providing dynamic information. It is rapid, uses a low dose of contrast, and may be useful in specific circumstances, such as in the acute stroke setting. However, it does not yet have spatial resolution comparable with standard contrast-enhanced MRA.