Geometry-independent inclusion of basal myocardium yields improved cardiac magnetic resonance agreement with echocardiography and necropsy quantified left-ventricular mass.

TitleGeometry-independent inclusion of basal myocardium yields improved cardiac magnetic resonance agreement with echocardiography and necropsy quantified left-ventricular mass.
Publication TypeJournal Article
Year of Publication2013
AuthorsSimprini LA, Goyal P, Codella N, Fieno DS, Afroz A, Mullally J, Cooper M, Wang Y, Finn JPaul, Devereux RB, Weinsaft JW
JournalJ Hypertens
Volume31
Issue10
Pagination2069-76
Date Published2013 Oct
ISSN1473-5598
KeywordsAged, Diastole, Echocardiography, Female, Heart Ventricles, Humans, Hypertrophy, Left Ventricular, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Middle Aged, Myocardial Infarction, Myocardium, Systole
Abstract

OBJECTIVES: Left-ventricular mass (LVM) is widely used to guide clinical decision-making. Cardiac magnetic resonance (CMR) quantifies LVM by planimetry of contiguous short-axis images, an approach dependent on reader-selection of images to be contoured. Established methods have applied different binary cut-offs using circumferential extent of left-ventricular myocardium to define the basal left ventricle (LV), omitting images containing lesser fractions of left-ventricular myocardium. This study tested impact of basal slice variability on LVM quantification.

METHODS: CMR was performed in patients and laboratory animals. LVM was quantified with full inclusion of left-ventricular myocardium, and by established methods that use different cut-offs to define the left-ventricular basal-most slice: 50% circumferential myocardium at end diastole alone (ED50), 50% circumferential myocardium throughout both end diastole and end systole (EDS50).

RESULTS: One hundred and fifty patients and 10 lab animals were studied. Among patients, fully inclusive LVM (172.6±42.3g) was higher vs. ED50 (167.2±41.8g) and EDS50 (150.6±41.1g; both P<0.001). Methodological differences yielded discrepancies regarding proportion of patients meeting established criteria for left-ventricular hypertrophy and chamber dilation (P<0.05). Fully inclusive LVM yielded smaller differences with echocardiography (Δ=11.0±28.8g) than did ED50 (Δ=16.4±29.1g) and EDS50 (Δ=33.2±28.7g; both P<0.001). Among lab animals, ex-vivo left-ventricular weight (69.8±13.2g) was similar to LVM calculated using fully inclusive (70.1±13.5g, P=0.67) and ED50 (69.4±13.9g; P=0.70) methods, whereas EDS50 differed significantly (67.9±14.9g; P=0.04).

CONCLUSION: Established CMR methods that discordantly define the basal-most LV produce significant differences in calculated LVM. Fully inclusive quantification, rather than binary cut-offs that omit basal left-ventricular myocardium, yields smallest CMR discrepancy with echocardiography-measured LVM and non-significant differences with necropsy-measured left-ventricular weight.

DOI10.1097/HJH.0b013e328362d935
Alternate JournalJ Hypertens
PubMed ID24107735
PubMed Central IDPMC4017912
Grant ListK23 HL102249 / HL / NHLBI NIH HHS / United States
K23 HL102249-01 / HL / NHLBI NIH HHS / United States
Related Institute: 
MRI Research Institute (MRIRI)

Weill Cornell Medicine
Department of Radiology
525 East 68th Street New York, NY 10065