Assessment of Improved Motion-Sensitized Driven Equilibrium (iMSDE) for Multi-contrast Vessel Wall Screening

Abstract

Purpose: We assessed the improved motion-sensitized driven equilibrium (iMSDE) technique for multiple contrast 3-dimensional vessel wall imaging at 3T.Methods: Carotid images were obtained using iMSDE combined with turbo field echo (iMSDE-TFE) and conventional double inversion-recovery turbo spin-echo (DIR-TSE) in 5 healthy adult subjects. The tissue signal-to-noise efficiency (SNR eff ), SNR divided by the square root of scan time, lumen-tissue contrast-to-noise efficiency (CNR eff ), CNR divided by the square root of scan time, and tissue signal intensity ratio (SIR) were measured in both techniques and compared.Results: The iMSDE-TFE had higher SNR eff and CNR eff (P < 0.01) and strong correlation in SIR (R = 0.92) compared to DIR-TSE.Conclusion: The iMSDE-TFE sequence is an efficient technique for vessel wall screening.

Efficacy of Maximum Intensity Projection of Contrast-Enhanced 3D Turbo-Spin Echo Imaging with Improved Motion-Sensitized Driven-Equilibrium Preparation in the Detection of Brain Metastases

“…iMSDE preparation improves contrast-to-noise ratio (CNR) between the vessel lumen and the adjacent tissue by selectively suppressing the flow of blood (14). By adding extra 180° refocusing pulses, iMSDE preparation also compensates signal loss, which was the limitation of a former MSDE preparation (1718). Therefore, iMSDE-TSE has a higher ability to differentiate small-sized tumors.…”

“…In this technique, we used a combination of iMSDE preparation and 3D low refocusing flip-angle TSE sequence. To construct iMSDE pre-pulse, we used motion-sensitizing gradients between the following radiofrequency pulses: 90° excitation pulse, two 180° refocusing pulses, and a 90° flip-back pulse (17). In addition, bipolar gradients were inserted in front of the 90° excitation pulse to compensate eddy currents (14).…”

“…MSDE- or iMSDE preparation is a black-blood imaging technique in which motion-sensitizing gradient pairs are used for phase dispersion among moving spins. Thus, flowing blood signals are suppressed with this technique (1718). Many previous studies have proved that small brain metastases can be effectively detected with MSDE or iMSDE-TSE (2131415).…”

Optimization of Improved Motion-sensitized Driven-equilibrium (iMSDE) blood suppression for carotid artery wall imaging

“…Wang et al previously reported that MSDE preparation achieved better blood suppression and higher muscle to lumen CNR efficiency than multi-slice DIR when using a T 2 -w FSE sequence [5]. Recently, Obara et al found 3D iMSDE prepared turbo field echo sequences had a higher muscle to lumen CNR efficiency than DIR prepared 2D FSE sequences for both T 1 -w and T 2 -w imaging in a group of five volunteers [18]. However, to date there have been no studies comparing the relative blood suppression and vessel wall CNR performance of iMSDE and DIR prepared FSE in generating the most clinically relevant T 1 - and T 2 - contrast weightings used for plaque imaging.…”

Hyperecho PROPELLER-MRI: Application to rapid high-resolution motion-insensitiveT2-weighted black-blood imaging of the carotid arterial vessel wall and plaque

“…Subsequently, we measured the CNR for comparing T 2 contrast quantitatively. The CNR was estimated for spinal cord and sternocleidomastoid muscle (CNR SC‐SM ) and sternocleidomastoid muscle and submandibular gland (CNR SG‐SM ) . The CNR SC‐SM and CNR SG‐SM were calculated by the following equations: where SI (SC) is the signal intensity of the spinal cord, SI (SM) is the signal intensity of the sternocleidomastoid muscle, SI (SG) is the signal intensity of the submandibular gland, and the corresponding SD noise is the standard deviation at the same location on the noise images.…”