Dark blood late enhancement imaging

Abstract

BackgroundBright blood late gadolinium enhancement (LGE) imaging typically achieves excellent contrast between infarcted and normal myocardium. However, the contrast between the myocardial infarction (MI) and the blood pool is frequently suboptimal. A large fraction of infarctions caused by coronary artery disease are sub-endocardial and thus adjacent to the blood pool. It is not infrequent that sub-endocardial MIs are difficult to detect or clearly delineate.MethodsIn this present work, an inversion recovery (IR) T2 preparation was combined with single shot steady state free precession imaging and respiratory motion corrected averaging to achieve dark blood LGE images with good signal to noise ratio while maintaining the desired spatial and temporal resolution. In this manner, imaging was conducted free-breathing, which has benefits for image quality, patient comfort, and clinical workflow in both adults and children. Furthermore, by using a phase sensitive inversion recovery reconstruction the blood signal may be made darker than the myocardium (i.e., negative signal values) thereby providing contrast between the blood and both the MI and remote myocardium. In the proposed approach, a single T1-map scout was used to measure the myocardial and blood T1 using a MOdified Look-Locker Inversion recovery (MOLLI) protocol and all protocol parameters were automatically calculated from these values within the sequence thereby simplifying the user interface.ResultsThe contrast to noise ratio (CNR) between MI and remote myocardium was measured in n = 30 subjects with subendocardial MI using both bright blood and dark blood protocols. The CNR for the dark blood protocol had a 13 % loss compared to the bright blood protocol. The CNR between the MI and blood pool was positive for all dark blood cases, and was negative in 63 % of the bright blood cases. The conspicuity of subendocardial fibrosis and MI was greatly improved by dark blood (DB) PSIR as well as the delineation of the subendocardial border.ConclusionsFree-breathing, dark blood PSIR LGE imaging was demonstrated to improve the visualization of subendocardial MI and fibrosis in cases with low contrast with adjacent blood pool. The proposed method also improves visualization of thin walled fibrous structures such as atrial walls and valves, as well as papillary muscles.

Clinical evaluation of two dark blood methods of late gadolinium quantification of ischemic scar

“…Several dark blood sequences have been described that attempt to overcome the issue of poor contrast between contrast‐enhanced blood pool and subendocardial infarction by the addition of extra magnetization pulses . FIDDLE (flow‐independent dark‐blood delayed enhancement) incorporates an additional magnetization preparation prior to the inversion pulse in a PSIR LGE sequence .…”

Acute Cardiac MRI Assessment of Radiofrequency Ablation Lesions for Pediatric Ventricular Arrhythmia: Feasibility and Clinical Correlation

“…Lesion conspicuity may also be dependent on tissue type and thickness. CMR is used in clinical practice to identify ventricular lesions including myocarditis and myocardial infarction, though is less commonly employed for study of the atria or other thin walled cardiac structures, which have a different tissue profile with increased challenges in differentiating tissue and lesion boundaries from the surrounding blood pool . Therefore, our findings in ventricular ablation lesions may not necessarily be applicable to atrial ablation lesions.…”

“…Evidence of ablation lesion by CMR was defined as per preclinical description of new LGE at the predicted ablation lesion location . Some patients in this study underwent additional imaging sequences for technical development of optimal acute postablation CMR imaging to increase likelihood of lesion identification using a novel dark blood imaging protocol using T2 prep between the IR preparation and readout allowing nulling of both myocardium and blood to increase contrast of the ablation lesion …”

Increased Prognostic Value of Query Amyloid Late Enhancement Score in Light-Chain Cardiac Amyloidosis

“…23 LGE is also a widely available clinical technique and its robustness has improved with the phase-sensitive inversion recovery technique. 30 Myocardial damage identified using LGE corresponds to the distribution of amyloid protein in the myocardium that includes all 4 chambers. 4 In multiple studies, the presence of LGE on CMR was independently correlated with a higher risk of adverse events in patients with AL amyloidosis.…”