Multimodality comparison of quantitative volumetric analysis of the right ventricle.
OBJECTIVE
We undertook volumetric analysis of the right ventricle (RV) by real-time 3-dimensional echocardiography (RT3DE), cardiac magnetic resonance (CMR), and cardiac computed tomography (CCT) on images obtained in RV-shaped phantoms and in patients with a wide range of RV geometry.


BACKGROUND
Assessment of the RV by 2-dimensional (2D) echocardiography remains challenging due to its unique geometry and limitations of the current analysis techniques. RT3DE, CMR, and CCT, which can quantify RV volumes, promise to overcome the limitations of 2D echocardiography.


METHODS
Images were analyzed using RV Analysis software. Volumes measured in vitro were compared with the true volumes. The human protocol included 28 patients who underwent RT3DE, CMR, and CT on the same day. Volumetric analysis of CMR images was used as a reference, against which RT3DE and CCT measurements were compared using linear regression and Bland-Altman analyses. To determine the reproducibility of the volumetric analysis, repeated measurements were performed for all 3 imaging modalities in 11 patients.


RESULTS
The in vitro measurements showed that: 1) volumetric analysis of CMR images yielded the most accurate measurements; 2) CCT measurements showed slight (4%) but consistent overestimation; and 3) RT3DE measurements showed small underestimation, but considerably wider margins of error. In humans, both RT3DE and CCT measurements correlated highly with the CMR reference (r=0.79 to 0.89) and showed the same trends of underestimation and overestimation noted in vitro. All interobserver and intraobserver variability values were <14%, with those of CMR being the highest.


CONCLUSIONS
Volumetric quantification of RV volume was performed on CMR, CCT, and RT3DE images. Eliminating analysis-related intermodality differences allowed fair comparisons and highlighted the unique limitations of each modality. Understanding these differences promises to aid in the functional assessment of the RV.
Sugeng
Lissa
L
University of Chicago Medical Center, Chicago, Illinois 60637, USA. lsugeng@medicine.bsd.uchicago.edu
Mor-Avi
Victor
V
Weinert
Lynn
L
Niel
Johannes
J
Ebner
Christian
C
Steringer-Mascherbauer
Regina
R
Bartolles
Ralf
R
Baumann
Rolf
R
Schummers
Georg
G
Lang
Roberto M
RM
Nesser
Hans-Joachim
HJ
D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D019560:Echocardiography, Three-Dimensional / Q000295:instrumentation; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000295:instrumentation