A novel prospective motion correction control system with slice tracking (MNav-CoS) was compared with three other prospective respiratory motion correction techniques in performing free-breathing cardiovascular diffusion tensor imaging (cDTI) acquisitions. Ten healthy volunteers underwent cDTI using an M2SE sequence. The performance of the proposed MNav-CoS was compared with three respiratory compensation techniques: multiple breath-holds (BH), free breathing with respiratory gating (Gate), and free breathing with single navigator slice tracking (Nav). Data for five diffusion weightings were acquired in a single mid-ventricular slice in end systole. MD, FA, and HA maps were calculated for each technique and combinations of low and high b-values. Data from the respiratory navigators were used to estimate the total amount of cardiac through-plane motion during free breathing. The metrics derived from the diffusion tensor for MNav-CoS with blow|bhigh = 50|450 s/mm2 were MD: 1. 48±0. 10μm⁄ms2 1. 48 0. 100. 3em m/ms², FA: 0. 39±0. 07 0. 39 0. 07, and HAg: -0. 82±0. 22°⁄% -0. 82 0. 22^{^}/\%. All of the other respiratory compensation techniques produced a similar range of results to the MNav-CoS technique. On average, the free-breathing acquisitions with slice tracking were three times shorter than using BH. The total amount of cardiac through-plane motion during the free-breathing acquisitions ranged from 4 to 10 mm with an average of 6. 2±1. 7mm 6. 2 1. 70. 3em mm. The MNav-CoS technique performed comparably to other commonly used respiratory compensation techniques. Prospective respiratory motion compensation, such as the slice tracking used with MNav-CoS, is a useful tool that offers time-saving benefits and compensates for through-plane motion present during free breathing. These techniques may be beneficial for performing longer cDTI acquisitions providing increased utility in a clinical context.
Jermy et al. (Mon,) studied this question.