Value of contrast-enhanced power Doppler sonography using a microbubble echo-enhancing agent in evaluation of small breast lesions.
OBJECTIVE
The purpose of this study was to prospectively evaluate the usefulness of contrast-enhanced power Doppler sonography (PDUS) using a microbubble echo-enhancing agent in differentiating between malignant and benign small breast lesions.


METHODS
Between July 1, 2000, and September 30, 2001, we performed gray-scale sonographic examination of patients in whom diagnostic sonography or screening mammography had revealed solid breast lesions measuring less than 2 cm in the largest dimension. The patients were then examined on PDUS before and after injection of a microbubble contrast agent. The sonographic findings for all 3 techniques, as well as the morphologic features of the Doppler signals for each patient before and after injection of the contrast agent on PDUS, were independently assessed. Each lesion was classified as "benign" or "malignant" on the basis of specific criteria for sonographic interpretation. A hemodynamic study was performed in which time-transit profiles of the Doppler signals on contrast-enhanced PDUS were generated using a computer-assisted program, and the results for each patient were compared with the findings of a histopathologic examination of surgical specimens.


RESULTS
Thirty-six patients (35 women and 1 man) with a mean age of 43.5 years (range, 18-69 years) were evaluated. The tumors ranged from 4 to 19 mm in the largest dimension. Histopathologic examination revealed that 19 tumors were benign and 17 were malignant. For morphologic diagnosis of the malignant lesions, the sensitivity of gray-scale sonography was 100%, compared with 29% for PDUS without contrast enhancement. The specificity of gray-scale sonography was 47%, compared with 74% for PDUS without contrast enhancement. Contrast-enhanced PDUS had a sensitivity of 71% and a specificity of 58%. The diagnostic accuracy was 72% for gray-scale sonography, 53% for PDUS without contrast enhancement, and 64% for contrast-enhanced PDUS. The time-transit profiles of the hemodynamic study did not reveal a statistically significant difference in the accuracy rates of contrast-enhanced PDUS between benign and malignant breast lesions.


CONCLUSIONS
Compared with PDUS without contrast enhancement, contrast-enhanced PDUS provides better visualization of the morphology of vascular Doppler signals that is characteristic of malignancy and therefore has a higher sensitivity and diagnostic accuracy, albeit a lower specificity. In differentiating between benign and malignant small breast lesions, contrast-enhanced PDUS can be helpful when used with gray-scale sonography and PDUS without contrast enhancement.
Kook
Shin-Ho
SH
Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, 108 Pyeong-Dong, Jongro-Gu, Seoul 110-108, South Korea.
Kwag
Hyon-Joo
HJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D001941:Breast Diseases / Q000000981:diagnostic imaging*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D018567:Breast Neoplasms, Male / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler / Q000379:methods*
D003287:Contrast Media