Accuracy of mitral valve area measurements using transthoracic rapid freehand 3-dimensional scanning: comparison with noninvasive and invasive methods.
OBJECTIVE
The feasibility and accuracy of direct transthoracic 3-dimensional (3D) mitral valve area (MVA) measurements obtained using freehand scanning was investigated in patients with mitral stenosis.


METHODS
A total of 30 patients (26 women, 4 men; aged 55 +/- 13 years) underwent a 2-dimensional (2D) and Doppler study 1 hour before percutaneous balloon mitral valvuloplasty. Transthoracic freehand data were acquired using a magnetic receiver attached to a broadband transducer, gated to electrocardiography and respiration. Volumetric MVA measurements from the left ventricle and left atrium were obtained and compared with MVA measurements derived from 2D planimetry, pressure half-time, and proximal isovelocity surface area. Invasive Gorlin MVA measurements were the gold standard for comparison.


RESULTS
In all, 29 patients (97%) had 3D data allowing MVA measurements. Direct 3D measurements from the left ventricle had the least bias (0.06 +/- 0.19 cm(2)) and tightest limits of agreement (-0.44 to 0.32) compared with left atrium measurements (0.17 +/- 0.25 cm(2) and -0.67 to 0.33, respectively). The proximal isovelocity surface area method (bias: 0.09 +/- 0.34 cm(2)) was the most accurate of all 2D methods followed by pressure half-time (0.17 +/- 0.36 cm(2)) and planimetry (0.21 +/- 0.29 cm(2)).


CONCLUSIONS
Direct 3D MVA measurements from the left ventricle using transthoracic freehand scanning are more accurate than traditional 2D methods.
Sugeng
Lissa
L
Department of Medicine, University of Chicago Medical Center, IL 60637, USA. lsugeng@medicine.bsd.uchicago.edu
Weinert
Lynn
L
Lammertin
Georgeanne
G
Thomas
Patrick
P
Spencer
Kirk T
KT
Decara
Jeanne M
JM
Mor-Avi
Victor
V
Huo
Dezheng
D
Feldman
Ted
T
Lang
Roberto M
RM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015150:Echocardiography, Doppler / Q000379:methods*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging*; D015588:Observer Variation