Kinetic analysis of lesions without mass effect on breast MRI using manual and computer-assisted methods.
OBJECTIVE
To analyse the kinetic characteristics of lesions without mass effect in dynamic breast MRI using manual and computer assisted methods.


METHODS
The enhancement pattern of 82 histopathologically verified lesions without mass effect (36 malignant, 46 benign) was evaluated on breast MRI using manual placement of a region of interest. Commercially available computer analysis software automatically assessed volume enhancement characteristics of a lesion voxelwise. Kinetic features evaluated included classification of the signal-intensity time curve as washout, plateau or persistent enhancement.


RESULTS
Unlike manual ROI placement, computer-aided analysis demonstrated a significant difference in enhancement pattern between benign (washout: 32.6%, plateau: 32.6%, persistent: 34.8%) and malignant lesions without mass effect (77.1%, 8.6%, 14.3% respectively, P < 0.01, two-sided Chi-squared test) following initial rapid signal increase. Mean percentage of washout voxel volumes within a lesion was significantly higher in malignant lesions than in benign lesions (11.9% +/-12.7 (SD) vs. 6.9% +/-11.3 (SD), P < 0.01, Mann-Whitney U Test). Conversely, the mean percentage of persistent voxel volumes was significantly lower in malignant lesions than in benign lesions (60.1% +/-21.1 (SD) vs. 79% +/-23 (SD), P < 0.01, Mann-Whitney U Test).


CONCLUSIONS
Computer-assisted enhancement pattern analysis might have diagnostic benefit in the evaluation of lesions without mass effect.
Department of Radiology, Klinikum Rechts der Isar, Technical University Munich, Ismaninger Strasse 22, 81675 Munich, Germany. Tibor.Vag@roe.med.tu-muenchen.de
Tibor
T
Vag
Pascal A T
PA
Baltzer
Matthias
M
Dietzel
Ramy
R
Zoubi
Mieczyslaw
M
Gajda
Oumar
O
Camara
Werner A
WA
Kaiser
D019540:Area Under Curve; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology*; D003287:Contrast Media / Q000494:pharmacology; D003952:Diagnostic Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007700:Kinetics; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015233:Models, Statistical; D010865:Pilot Projects; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012984:Software; D013997:Time Factors
D003287:Contrast Media