Cardiac computed tomographic imaging to evaluate myocardial scarring/fibrosis in patients with hypertrophic cardiomyopathy: a comparison with cardiac magnetic resonance imaging

Abstract

Contrast enhanced magnetic resonance imaging (CeMRI) reliably identifies myocardial fibrosis in patients with hypertrophic cardiomyopathy (HCM). However, many patients have contraindications to ceMRI. Previous studies have shown that contrast enhanced multi-detector computed tomography (ceMDCT) can visualize focal scars following myocardial infarction in experimental animals and patients. The purpose of this manuscript is to assess the ability of ceMDCT to detect focal myocardial scars in patients with HCM. Twelve HCM patients underwent ceMRI and ceMDCT. Fibrotic areas of myocardium were defined as focal or diffuse areas of fibrosis. The mean signal intensity in ceMRI and attenuation values in ceMDCT of the fibrotic regions, normal myocardium and left ventricle blood pool contrast were measured using qualitative and quantitative analysis. Focal scar mass was calculated using both techniques. Focal scars were detected in 9 patients and diffuse fibrosis was visualized in all patients by ceMRI. Differences between normalized SI of normal myocardium and focal scars, normal and diffuse areas of fibrosis, and diffuse fibrosis and focal scars were significant for both ceMRI and ceMDCT (p < 0.05). Diffuse fibrosis was poorly visualized by ceMDCT but was detectable using quantitative measurements. CeMDCT has potential to detect focal myocardial scars in patients with HCM who have contraindications to ceMRI study. However, ceMDCT does not enable adequate visualization of diffuse myocardial fibrosis, and thus is less well suited than ceMRI for assessment of total burden of fibrosis. This limitation may be overcome using quantitative methodology.

Late enhanced computed tomography in Hypertrophic Cardiomyopathy enables accurate left-ventricular volumetry

“…LeMDCT was introduced for the demonstration of LE in selected [12][13][14][15][16] and consecutive patients with HCM [17]. LE in HCM was proven to be of prognostic relevance [18].…”

“…The addition of LE to further prognostically relevant volumetric parameters describing LV function and dimensions has been shown to increase knowledge regarding a patient's health, cardiac status, and prognosis [24]. This is the first analysis showing low-contrast leMDCT indicated for the visualization of LE, marking (intra)myocardial fibrosis in HCM [12][13][14][15][16][17][18] or post-ischemic scars in CAD [7][8][9][10][11], to allow for accurate LV volumetry ( Table 2). As known from full-contrast MDCT datasets (acquired during first pass) [23,25], LV-MM can be assessed in close analogy to the current gold standard method -regardless of whether it is performed semiautomatically or manually (Fig.…”

“…Image postprocessing was performed on a commercially available workstation (Leonardo™; Siemens Medical Solutions, Forchheim, Germany). As described elsewhere, multiplanar reformations (MPRs) were generated to slices (thickness 5 mm) covering the entire LV from the base to the apex in short-axis views without gaps or overlap [12,17,22].…”

“…In consideration of the prognostic role of fibrosis, and in light of the growing body of validated leMDCT data for LE in HCM [12][13][14][15][16][17][18], leMDCT may gain increasing importance with regard to imaging of fibrosis in the context of cardiovascular risk assessment in affected patients. However, pure detection and quantification of LE may not be as relevant.…”

Imaging in hypertrophic cardiomyopathy. Expert consensus statement of the Polish Clinical Forum for Cardiovascular Imaging

“…Za pomocą CT można wykazać ogniskowe zwłóknienie w mięśniu sercowym, ale referencyjną metodą pozostaje nadal CMR, zwłaszcza w przypadku oceny procesu rozlanego [176,177]. Dotychczasowe badania dotyczyły małych liczebnie grup i wyselekcjonowanych pacjentów z HCM, dlatego przydatność tej metody musi zostać jeszcze potwierdzona.…”