Inter-study variability in left ventricular mass measurement. Comparison between M-mode echography and MRI.
In order to compare variability in M-mode echography and MRI in the assessment of left ventricular mass, 20 echogenic patients without evidence of coronary artery disease were investigated. Two MR and two M-echo examinations were performed within 4 days by different trained operators, each unaware of the other's results. M-mode echo was carried out according to Devereux's method, using the 'Penn-Cube' formula. MR protocol included multislice (8 to 12) true, short-axis spin-echo imaging (10 mm thick with a 1 to 3 mm gap) encompassing the entire left ventricle. Planimetry was manually traced with standardized window settings. Correlations between both echographic and both MR measurements showed r = 0.89, SEE = 22.7 g and r = 0.96, SEE = 11.2 g, respectively. Mean inter-study variability was 11 +/- 6.4% and 6.75 +/- 3.8% (P = 0.0021). The threshold value corresponding to the 95th percentile of the variability data was 21.5% for echography and 13.5% for MR. In conclusion, MR appeared to be a significantly more reproducible examination tool, when compared with M-mode echo, for the evaluation of left ventricular mass (variability, 63% higher with echo than with MR). The main practical consequence of this result lies in the reduced number of patients required to demonstrate a significant change in the LVM with MR as compared with echography.
Germain
P
P
Cardiologie, Hôpital de Hautepierre, Strasbourg, France.
Roul
G
G
Kastler
B
B
Mossard
J M
JM
Bareiss
P
P
Sacrez
A
A
D000328:Adult; D002306:Cardiac Volume / Q000502:physiology*; D006332:Cardiomegaly / Q000175:diagnosis* / Q000503:physiopathology; D009202:Cardiomyopathies / Q000175:diagnosis / Q000503:physiopathology; D004452:Echocardiography / Q000295:instrumentation; D005260:Female; D006349:Heart Valve Diseases / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D013617:Tachycardia, Supraventricular / Q000175:diagnosis / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*