False-positive breast cancer results may be reduced by water diffusion measurements with MRI
By determining how water moves through tissue, water diffusion measurements with MRI could decrease false-positive breast cancer results and reduce preventable biopsies, according to recent study findings. Researchers add that the technique could also improve patient management by distinguishing high-risk lesions from other nonmalignant subtypes.
In recent years, dynamic contrast-enhanced MRI (DCE-MRI) has emerged as a beneficial tool in breast cancer detection and staging. However, one of its main shortcomings is the considerable number of false-positive results that require biopsies.
Diffusion-weighted imaging (DWI) is a possible solution. This is an MRI technique that calculates the apparent diffusion coefficient (ADC), a measure of how water moves through tissue. Because normal breast tissue has a high ADC (water moves through it relatively freely) and most cancers have a lower ADC (because their cells are more tightly packed and restrict water motion), DWI is a promising tool for differentiating between benign and malignant breast lesions.
“DWI has been used mostly in neurological applications, but it’s been studied more recently in breast imaging,” said Savannah C. Partridge, PhD, research associate professor at the University of Washington, Seattle Cancer Care Alliance. “It only adds a couple of minutes to the MRI exam and does not require additional contrast or any extra hardware.”
For the new study published online in the journal Radiology, Partridge and colleagues evaluated the DWI characteristics of nonmalignant lesions in 165 women. Using ADC values above a previously determined diagnostic threshold, DWI effectively characterized 46% of nonmalignant breast lesions identified as false-positive findings on DCE-MRI as benign.
“We were excited to see the number of false positives that could be reduced through this approach,” Partridge said. “DWI gives us extra microstructural information to distinguish among lesions. We can use ADC values to draw a cutoff above which we might not need to do a biopsy.”
A multicenter trial to validate the findings is in the planning stages. Researchers strive to determine the best way to incorporate ADC measures into clinical breast MRI interpretations.
Source: RSNA