Non-contrast DWI for Supplemental Screening

Non-contrast DWI for Supplemental Screening of Women With Dense Breasts

Diffusion-weighted imaging (DWI) is a short (under 5 minutes) non-contrast MRI technique that has shown promise for the detection and characterization of breast cancer. Our preliminary data has shown that DWI holds potential for detecting mammographically and clinically-occult breast cancers. However, current technical limitations reduce the sensitivity of DWI for screening applications.

The identification of a screening tool to complement mammography that is more accurate than ultrasound and faster, less expensive, and safer than conventional contrast-enhanced MRI would have significant clinical impact by improving the early detection of cancer in women with dense breasts. We hypothesize that an optimized DWI approach will enable detection of mammographically occult breast cancer in women with dense breasts with high sensitivity and low false positive rate.

Hypothesis: With technical optimizations, non-contrast DWI can detect clinically and mammographically occult breast cancer in women with dense breasts with high sensitivity and low false positive rate.

Aim 1: Improve the breast DWI technique to maximize spatial resolution, reduce distortion, and increase lesion contrast.

• Develop novel DWI acquisition to increase spatial resolution and reduce distortion (using reduced field of-view and/or multishot echo planar imaging techniques)
• Identify optimal diffusion sensitization (b-value) to maximize conspicuity of cancers in women with dense breasts

Aim 2: Develop interpretation tools to optimize diagnostic performance for detecting cancer on DWI.

• Determine quantitative DWI thresholds (contrast-to-noise ratio, apparent diffusion coefficient [ADC]) that best differentiate benign and malignant lesions (i.e. maximize sensitivity and specificity)
• Develop computer aided assessment tools to facilitate clinical implementation and optimize reader accuracy

Aim 3: Test the performance of the optimized DWI approach for detecting clinically and mammographically-occult cancer in women with dense breasts.

• Conduct a controlled reader study of non-contrast DWI alone for breast cancer detection
• Perform receiver operating characteristic (ROC) analysis and determine the sensitivity and specificity for detection of mammographically occult cancer

Inclusion Criteria:

1. Women aged 18 or older
2. Dense breast identified on mammogram

Exclusion Criteria:

1. Contra-indication to contrast-enhanced breast MRI (e.g. renal insufficiency with GFR<60, contrast allergy, incompatible metal)
2. Patients who currently are undergoing chemoprevention therapy (e.g. aromatase inhibitors or selective estrogen receptor modulators)
3. Women who are pregnant