Myocardial scar imaging by standard single-energy and dual-energy late enhancement CT: Comparison with pathology and electroanatomic map in an experimental chronic infarct porcine model

Abstract

Background Myocardial scar is a substrate for ventricular tachycardia and sudden cardiac death. Late enhancement computed tomography (CT) imaging can detect scar, but it remains unclear whether newer late enhancement dual-energy (LE-DECT) acquisition has benefit over standard single-energy late enhancement (LE-CT). Objective We aim to compare late enhancement CT using newer LE-DECT acquisition and single-energy LE-CT acquisitions to pathology and electroanatomical map (EAM) in an experimental chronic myocardial infarction (MI) porcine study. Methods In 8 chronic MI pigs (59±5 kg), we performed dual-source CT, EAM, and pathology. For CT imaging, we performed 3 acquisitions at 10 minutes post-contrast: LE-CT 80 kV, LE-CT 100 kV, and LE-DECT with two post-processing software settings. Results Of the sequences, LE-CT 100 kV provided the best contrast-to-noise ratio (all p≤0.03) and correlation to pathology for scar (ρ=0.88). While LE-DECT overestimated scar (both p=0.02), LE-CT images did not (both p=0.08). On a segment basis (n=136), all CT sequences had high specificity (87–93%) and modest sensitivity (50–67%), with LE-CT 100 kV having the highest specificity of 93% for scar detection compared to pathology and agreement with EAM (κ 0.69). Conclusions Standard single-energy LE-CT, particularly 100kV, matched better to pathology and EAM than dual-energy LE-DECT for scar detection. Larger human trials as well as more technical-based studies that optimize varying different energies with newer hardware and software are warranted.

Comprehensive use of cardiac computed tomography to guide left ventricular lead placement in cardiac resynchronization therapy

“… 6 Rapid acquisition of 3-dimensional, isotropic, whole heart data sets with submillimeter spatial resolution can accurately delineate the coronary venous tree, 7 noninvasively assess regional and global LV function, 8 and detect regional hypoperfusion/myocardial scar. 9 Recently, CT has evaluated regional and global LV dyssynchrony and areas of LMA by calculating the stretch of the endocardial surface throughout the cardiac cycle (stretch quantifier for endocardial engraved zones [SQUEEZ]). 10 In patients with existing pacing systems undergoing CRT, we hypothesized that preprocedural cardiac CT-SQUEEZ by targeting areas of LMA and avoiding myocardial scar could guide LV lead placement through identification of the optimal venous target.…”

Principles and techniques of imaging in identifying the substrate of ventricular arrhythmia

“…Comparable to LGE-CMR, late enhancement CT can be acquired approximately 10 minutes after contrast injection with a standard single-energy or dual-energy cardiac CT. Both have been demonstrated to correlate well with LGE-CMR assessed scar as well as histopathologic findings 112 - 115 In addition, perfusion defects obtained from qualitative first-pass CT perfusion imaging may provide information on the extent and location of scar. Few studies have assessed the role of contrast enhanced CT in identifying the arrhythmic substrate.…”

Delayed enhancement cardiac computed tomography for the assessment of myocardial infarction: from bench to bedside

“…In opposition, animal data using dual energy imaging acquired by dual source CT scanners (one tube with 165 mAs/rotation at 100 kV and the second tube with 140 mAs/rotation at 140 kV) has shown inferior results regarding scar imaging compared to single energy 100 kV CTDE imaging (49).…”

“…The aforementioned technical advancements might also potentially encourage further research towards the use of dual energy CTDE for a number of clinical applications other than ICM. Indeed, the usefulness of CTDE using single energy has shown promising findings among patients with non-ischemic cardiomyopathies including HCM, myocarditis, and even for the guidance of electro-anatomic mapping for ventricular tachycardia ablation (31,49,(54)(55)(56)(57)(58). This might be of particular interest among patients with implantable cardioverters (58).…”