S. Schick et al., DIFFERENTIATION OF BENIGN AND MALIGNANT-TUMORS OF THE PAROTID-GLAND -VALUE OF PULSED DOPPLER AND COLOR DOPPLER SONOGRAPHY, European radiology, 8(8), 1998, pp. 1462-1467
To establish criteria for the differentiation of benign and malignant
tumors of the parotid gland using color Doppler sonography (CDS) and p
ulsed Doppler sonography (PDS) we examined 37 patients with parotid tu
mors by gray-scale ultrasound, CDS and PDS. Tumor vascularization disp
layed by CDS was graded subjectively on a 4-point scale (0 = no vascul
arization, 3 = high vascularization). From the Doppler spectrum, the h
ighest systolic peak flow velocity, the resistive index (RI), and the
pulsatility index (PI) were calculated. There were 11 malignant and 26
benign tumors. Tumor vascularization by CDS was grade 0 or 1 in 88.5%
of benign lesions, whereas it was grade 2 or 3 in 82% of malignant le
sions (P < 0.0001). The highest systolic peak flow velocity and statis
tically significantly higher in malignant lesions than in benign lesio
ns. Using a threshold systolic peak flow velocity of 25 cm/s, sensitiv
ity was 72% and specificity was 88% for the detection of a malignant t
umor. Evaluation of tumor vascularization by CDS and PDS cannot differ
entiate between benign and malignant parotid tumors with certainty. Ho
wever, high vascularization and high systolic peak flow velocity in tu
mor vessels should raise the suspicion of malignancy, even if tumor mo
rphology on gray-scale sonography indicates a benign lesion.