The following question has been sent by Judy Oltmann, CTA Technologist, USA:

My question may have appeared vaque before. My radiology group has had a consistent complaint concerning the mottle or graininess, both terms applied, to the axial datasets acquired during our coronary scans with the Definition scanner. We have applied new kernal and slice thickness, increased flow rates for contrast and a fixed pitch with certain patients. The temporal resolution is too grainy for them at 82 ms, but much sharper than a reconstruction at 165 ms, resembling a 64 slice cardiac acquisition. The comment is that the 82 ms recon makes the diagnosis of a soft plaque difficult due to the mottle on the axial dataset.
I would like the opinion of other groups who are interpreting cardiac studies to give me some insight as too any possible solutions to their complaints. Also understand that in South Texas, our patients population averages 200 LBS and more.

Savvas Nicolaou, MD, University of British Columbia, Canada:

Some options that might help would be to increase the flow rate to 7 cc/sec and also use a 370 mg/ml iodine contrast material or higher if available to improve contrast and allows the software analysis to work with better efficiency.
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I would also use b blockers to decrease the heart rate to at least 60 bpm or below. This would help with spatial resolution as decreasing the motion will help eliminate blurring of structures and optimize visualization of the coronary arteries and plaques. This would also allow you to use the XXL mode and not pay a penalty with higher temporal resolution.
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I would also abandon t using the automated best phase to pick the high resolution data set to analyze the coronary arteries, and try to pick the best phase manually were the least amount of motion is present in the RCA and LAD we have found this works much better than the automated best phase that is available with the cardiac software.
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Hope this helps
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Thank you
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Dr Savvas Nicolaou

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