Power Doppler vascularity index for predicting malignancy of adnexal masses.
OBJECTIVE
To assess the performance of a power Doppler vascularity index in the preoperative diagnosis of ovarian malignancy.


METHODS
Adnexal masses (n = 101) were examined prospectively with power Doppler ultrasonography before surgical treatment. The tumor vascularity index (power Doppler index, PDI) was determined by quantification of the number of pixels in a defined region of interest according to the formula: number of colored pixels/(total number of pixels minus the number of pixels in the fluid or avascular areas). It was estimated on selected frames of the tumors using an in-house color-quantifying program added to MATLAB 6.0 software. Inter- and intraobserver reproducibilities of PDI assessment were evaluated. Intratumoral blood flow velocity waveforms were obtained to determine the lowest resistance index (RI). A subjective visual score of power Doppler signals in the tumor was used to classify it as having low, moderate or high vascularity. The discriminatory ability of this score was compared to that of RI and PDI measurement.


RESULTS
Histology identified 23 malignant and 78 benign lesions. The PDI was considerably higher in malignant than in benign lesions (0.34 +/- 0.04 vs. 0.12 +/- 0.06; P < 0.001). The intra- and interobserver variabilities of PDI were low (intraclass correlation coefficients of 0.99 and 0.97, respectively). The PDI cut-off value to differentiate malignant from benign tumors was set at 0.265 (26.5% of the tumor being colored). Using this cut-off, sensitivity and specificity were 100% (95% CI, 87.8-100.0) and 97.4% (95% CI, 91.0-99.7) compared to 78.3% (95% CI, 56.3-92.5) and 83.1% (95% CI, 72.9-90.7) for RI (cut-off value of 0.53) and 78.3% (95% CI, 56.3-92.5) and 94.9% (95% CI, 87.4-98.6) for visual scoring. Logistic regression demonstrated that PDI was the best parameter for differentiating between malignant and benign tumors.


CONCLUSIONS
The power Doppler vascularity index obtained using customized color quantifying software has high diagnostic value in discriminating between benign and malignant adnexal masses.
Marret
H
H
Department of Gynaecology, Obstetrics, Fetal Medicine and Human Reproduction, Tours, France. marret@med.univ-tours.fr
Sauget
S
S
Giraudeau
B
B
Body
G
G
Tranquart
F
F
D000290:Adnexa Uteri / Q000098:blood supply / Q000000981:diagnostic imaging*; D000291:Adnexal Diseases / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging*; D010053:Ovary / Q000000981:diagnostic imaging / Q000503:physiopathology; D010865:Pilot Projects; D011446:Prospective Studies; D012372:ROC Curve; D012039:Regional Blood Flow; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler / Q000379:methods*