Segmentation of cardiac cine MR images of left and right ventricles: interactive semiautomated methods and manual contouring by two readers with different education and experience.
OBJECTIVE
To test interactive semiautomated methods (ISAM) vs. manual contouring (MC) in segmenting cardiac cine MR images.


METHODS
Short-axis images of 10 consecutive patients (1.5-81.5 years of age) were evaluated by a trained radiologist (R1) and a low-trained engineer (R2). Each of them performed four independent reading sessions: two using ISAM and two using MC. Left ventricle (LV) myocardial mass (LVMM), LV ejection fraction (LVEF), and right ventricle (RV) ejection fraction (RVEF) were obtained. Bland-Altman analysis and Wilcoxon test were used.


RESULTS
The bias +/- 2 standard deviations (SD) of ISAM vs. MC for LVMM (g) was -5.7 +/- 13.4 (R1) and -5.5 +/- 26.3 (R2); for LVEF (%) it was -1.4 +/- 13.0 and -2.9 +/- and 6.8; for RVEF (%) it was 2.6 +/- 17.0 and 1.0 +/- 16.7. Considering both readers/methods, intraobserver bias +/- 2 SD ranged from 0.3 +/- 25.3 to -6.8 +/- 23.0, from 0.2 +/- 8.0 to -4.4 +/- 15.8, and from -0.0 +/- 26.4 to -4.6 +/- 27.8, respectively. Interobserver bias +/- 2 SD was -25.9 +/- 46.0 (ISAM) and 26.1 +/- 36.4 (MC), -1.4 +/- 8.6 (ISAM) and 0.1 +/- 17.9 (MC), and 0.7 +/- 23.3 and 2.3 +/- 29.8, respectively. Larger SDs were systematically found for RVEF vs. LVEF. Segmentation times: five minutes for LV with ISAM (both readers); for LV with MC, six (R1) vs. nine minutes (R2) (P < 0.001); five to six minutes for RV (both methods /readers). R2 significantly reduced LV segmentation times from nine (MC) to five minutes (ISAM) (P < 0.001).


CONCLUSIONS
A highly reproducible LV segmentation was performed in a short time by R1. The advantage of ISAM vs. MC for LV segmentation was a time saving only for R2. For RVEF, a lower reproducibility was observed for both methods and readers.
Sardanelli
Francesco
F
Department of Medical and Surgical Sciences, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Policlinico San Donato, University of Milan School of Medicine, San Donato Milanese, Milan, Italy. f.sardanelli@grupposandonato.it
Quarenghi
Matteo
M
Di Leo
Giovanni
G
Boccaccini
Leonardo
L
Schiavi
Angelo
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001698:Biomedical Engineering; D002648:Child; D002675:Child, Preschool; D004522:Educational Status; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011871:Radiology; D015203:Reproducibility of Results; D013318:Stroke Volume; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right