In reality, the heart is deformable and the motion is therefore more complex. All in vivo B2B-RMC acquisitions to date have been acquired in healthy volunteers, but we are now actively recruiting patients. In general, breathing patterns are more erratic in the patient population with greater respiratory drift than for healthy subjects, and we therefore might expect the benefits of B2B-RMC to be more pronounced. In our study group, we have only targeted the right coronary artery as it is the more mobile and therefore the more challenging imaging target. However, preliminary attempts in imaging the left coronary artery system have also been successful despite a generally reduced

volume of fat surrounding Small Molecule Compound Library these arteries. Also, vessel diameter and sharpness were only measured in the first 40 mm of the artery. This is partly due to the localized nature of the cross-correlation method which was used to selectively

correct for the respiratory motion of the proximal/mid artery, but these measurements also become increasingly difficult around the escalating number of branch points more distally. Nonetheless, we have qualitatively demonstrated that the B2B-RMC may be used to correct for respiratory motion in the distal right coronary artery by selecting appropriate regions of interest to cross-correlate. In the future, nonrigid implementations will be investigated in order to correct whole-heart 3D coronary artery acquisitions. A further limitation Screening Library purchase of this study is that although SNR and contrast to noise ratio are important determinants of image quality, the inherently different mafosfamide image contrast between the 3D spiral and nav-bSSFP techniques used in the in vivo

studies meant that such measures were inappropriate for comparing the performance of respiratory compensation strategies in this context. While the ideal solution would have been to perform an additional identical 3D spiral acquisition with a 5-mm navigator gating window, this was not possible due to time constraints. One potential alternative would have been to acquire a navigator gated 3D spiral acquisition with B2B-RMC and a 5-mm gating window to enable gated and corrected images to be reconstructed from the same data set. It is also possible to implement the bSSFP with the B2B-RMC technique. However, both of these options require considerable modifications to the pulse sequence and image reconstruction software which were not possible at the time of this study. In conclusion, the B2B-RMC technique can be used to correct for respiratory motion with 99.7% respiratory efficiency as well as a navigator-based technique with a 5-mm gating window (44.0% efficient), using vessel sharpness and vessel diameter from phantom and right coronary artery imaging to quantitatively compare the methods. “
“In the above article, there were editorial errors in Eqs. (5), (6) and (7). Below are the equations as they should have appeared.