DRA

J Cardiovasc Magn Reson. 2008 Apr 28;10:18

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Minimize Dark Rim Artifact during perfusion, by:

1. Decreasing injection rate (to 4 mL/sec) = 3.1 sec injection time at 50% dilution and 0.05 mmol/kg.
2. Increase resolution if possible.
3. Reduce [Gd]. Favor 50% dilution. This may make injection rate reduction to 4 mL/sec unnecessary.
4. Reduce Stress/Rest Gd dose. At least down to 0.075 mmol/kg. Maybe 0.05 mmol/kg? Inject the remainder for LGE after rest scan. A smaller dose helps keep the duration of injection short. Minimal effect on LGE (slightly less Gd for stress).
5. Increase Parallel Imaging Factor (PIF).
   1. Allows better resolution in number 1 above.
   2. Thickness of the DRA inversely proportional to square root of PIF!
   3. Improve probability of more planes in 1 RR.
6. Sequential ordering. Avoid Centric. Probably already done.
7. Avoid b-SSFP. We already use GRE based Saturation Recovery.
8. Reduce Cardiac Motion.
   1. Just enough Adenosine to be effective but we want nothing more than that.
   2. Higher PIF helps reduce effect of cardiac motion between phase encodes.

Comparison between a dark rim artifact (DRA, top) and a real perfusion defect (bottom) from two different patients. From left to right are shown the contrast arrival to the left ventricle, the myocardium, and finally recirculation. A DRA artifact usually lasts for a few heartbeats while a real defect tends to be more persistent.