Simultaneous bright‐ and black‐blood whole‐heart MRI for noncontrast enhanced coronary lumen and thrombus visualization

Abstract

PurposeTo develop a 3D whole‐heart Bright‐blood and black‐blOOd phase SensiTive (BOOST) inversion recovery sequence for simultaneous noncontrast enhanced coronary lumen and thrombus/hemorrhage visualization.MethodsThe proposed sequence alternates the acquisition of two bright‐blood datasets preceded by different preparatory pulses to obtain variations in blood/myocardium contrast, which then are combined in a phase‐sensitive inversion recovery (PSIR)‐like reconstruction to obtain a third, coregistered, black‐blood dataset. The bright‐blood datasets are used for both visualization of the coronary lumen and motion estimation, whereas the complementary black‐blood dataset potentially allows for thrombus/hemorrhage visualization. Furthermore, integration with 2D image‐based navigation enables 100% scan efficiency and predictable scan times. The proposed sequence was compared to conventional coronary MR angiography (CMRA) and PSIR sequences in a standardized phantom and in healthy subjects. Feasibility for thrombus depiction was tested ex vivo.ResultsWith BOOST, the coronary lumen is visualized with significantly higher (P < 0.05) contrast‐to‐noise ratio and vessel sharpness when compared to conventional CMRA. Furthermore, BOOST showed effective blood signal suppression as well as feasibility for thrombus visualization ex vivo.ConclusionA new PSIR sequence for noncontrast enhanced simultaneous coronary lumen and thrombus/hemorrhage detection was developed. The sequence provided improved coronary lumen depiction and showed potential for thrombus visualization. Magn Reson Med 79:1460–1472, 2018. © 2017 International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Non‐contrast enhanced simultaneous 3D whole‐heart bright‐blood pulmonary veins visualization and black‐blood quantification of atrial wall thickness

“…Higher SNR ven and CNR ven resulted in statistically improved pulmonary and coronary vein delineation in MTC‐IR BOOST; in fact, increased %VS and VL were quantified for rPV, lPV, AIV, and PIV in comparison to T 2 Prep‐IR BOOST. The 2 bright‐blood volumes, obtained with the MT‐prepared BOOST sequence proposed in this study and with the previously published T 2 ‐prepared BOOST, provided comparable coronary artery delineation in terms of %VS and VL for both RCA and LAD. Figure shows arterial and venous systems depiction obtained with MTC‐IR BOOST and with T 2 Prep‐IR BOOST in 2 representative subjects.…”

“…Our previously introduced T 2 ‐prepared BOOST was found to provide degraded depiction of the cardiac venous system and of the PVs; therefore, such a sequence cannot be directly used for the planning of RF ablation procedures. Conversely, the MT‐prepared BOOST sequence enables good vein delineation . In this study, a high frequency offset (3000 Hz) was chosen for MT preparation to minimize image artefacts in regions with imperfect B 0 and shimming and to minimize on‐resonance saturation .…”

“…Furthermore, the MT‐prepared BOOST sequence proposed in this study is more suitable not only for pulmonary and coronary veins depiction (bright‐blood MTC‐IR BOOST) but also for atrial wall segmentation and AWT quantification (black‐blood PSIR BOOST) when compared to the T 2 ‐prepared counterpart (Figure ). The original T 2 ‐prepared BOOST sequence considers translational respiratory motion solely in the process of image reconstruction; in contrast, this study integrates BOOST with non‐rigid respiratory motion correction. Consistently with previous findings, the use of non‐rigid respiratory motion correction significantly improves image quality when compared to translational motion correction only; this aspect may be particularly beneficial for a future wider validation in patients.…”

“…The sequence exploits a Cartesian trajectory with spiral profile order, where consecutive spiral interleaves are rotated by the golden angle. The implementation of the BOOST sequence described in Ginami et al— originally proposed for the simultaneous pre‐contrast visualization of the coronary artery lumen (bright‐blood) and of coronary thrombus and intraplaque hemorrhage (black‐blood) — alternates the acquisition of 2 differently weighted bright‐blood volumes (T 2 Prep‐IR BOOST and T 2 Prep BOOST) that are subsequently combined in a PSIR‐like reconstruction to obtain a third, complementary, and fully co‐registered black‐blood volume. Because of the detrimental effect of the T 2 Prep pre‐pulse on coronary vein depiction, this sequence implementation might not be directly applicable for the visualization of the cardiac venous system.…”

Whole‐heart T1 mapping using a 2D fat image navigator for respiratory motion compensation

“…Self‐navigation and image‐based navigator (iNAV) techniques have been recently proposed to directly estimate the respiratory‐induced motion of the heart and correct for it, enabling 100% respiratory scan efficiency and therefore shorter and predictable scan times. iNAV techniques have been used for coronary artery MRI and shown good motion estimation and correction performance . However, iNAVs have not yet been extended to 3D T 1 mapping because of the technical challenges of this technique that include: interference between the image navigator and the T 1 ‐weighted images that can affect the accuracy and precision of the T 1 measurement, low SNR of the navigators because of the effect of saturation pulses and the long T 1 of blood, and change of contrast of the navigators during the acquisition of different T 1 ‐weighted images.…”