Breast lesions: imaging with contrast-enhanced subharmonic US--initial experience.

Area of Science:

• Radiology
• Medical Imaging
• Oncology

Background:

• Accurate breast cancer diagnosis is crucial for effective treatment.
• Conventional imaging modalities like mammography and standard ultrasonography (US) have limitations in sensitivity and specificity.
• Novel imaging techniques are needed to improve diagnostic accuracy.

Purpose of the Study:

• To prospectively compare the diagnostic accuracy of gray-scale subharmonic imaging (SHI) against standard gray-scale US, power Doppler US (with and without contrast), and mammography for breast cancer detection.
• To evaluate the performance of SHI using histopathologic or clinical follow-up as the reference standard.

Main Methods:

• A pilot study involving 14 women with 16 biopsy-proved breast lesions.
• Modified US scanner for gray-scale SHI (transmitting at 4.4 MHz, receiving at 2.2 MHz).
• Comparison of imaging techniques including precontrast gray-scale US, power Doppler US, contrast-enhanced power Doppler US, and gray-scale SHI.

Main Results:

• SHI demonstrated 75% sensitivity and 83% specificity.
• Mammography had 100% sensitivity but only 20% specificity.
• SHI showed superior contrast enhancement compared to power Doppler (100% vs. 44% good/excellent enhancement).
• Area under the ROC curve for SHI was 0.78, compared to 0.76 for mammography and lower for US modes.

Conclusions:

• Gray-scale SHI shows potential to enhance breast cancer diagnosis compared to conventional US and mammography.
• Further studies with larger cohorts are warranted to confirm these findings.
• SHI's improved contrast enhancement suggests a valuable role in breast lesion characterization.