Quantitative evaluation of k‐space reordering schemes for compatible dual‐echo arteriovenography (CODEA)

Compatible dual‐echo arteriovenography (CODEA) is a recently developed technique for simultaneous acquisition of time‐of‐flight MR angiogram (MRA) and blood oxygenation level–dependent MR venogram (MRV) using an echo‐specific k‐space reordering scheme. In this study, we evaluated and compared the image quality of CODEA MRA/MRV implemented with two different schemes of echo‐specific k‐space reordering: one along the 1st phase‐encode direction (one‐dimensional) only and the other along both phase‐encode directions (two‐dimensional). Our results showed that use of the two‐dimensional reordering scheme improved contrast‐to‐noise ratio of small arteries by ～8%, although not statistically significant (P > 0.1). Contrast‐to‐noise ratio of the CODEA MRAs was better than that for the non‐CODEA dual‐echo MRA without k‐space reordering (contrast‐to‐noise ratio increased in large arteries by ～10% and small arteries by ～45%; P < 0.1). Contrast‐to‐noise ratio of the CODEA MRAs was comparable with that of the conventional single‐echo MRA for large arteries but reduced by ～20% for small arteries. Contrast‐to‐noise ratio of veins on the CODEA MRVs was equivalent to that of the conventional single‐echo and the non‐CODEA dual‐echo MRVs. However, some veins in the CODEA MRVs showed stronger contrast than those in the single‐echo MRV in relation to the contrast of neighboring arterial signals. Magn Reson Med 63:1404–1410, 2010. © 2010 Wiley‐Liss, Inc.