Bilateral breast imaging

MRI can detect breast cancer with a sensitivity approaching 100 percent, but it is not recommended for routine screening because it has a specificity of only 37 to 97 percent. A lack of standardization of imaging protocols may account for this, according to Dr. Paul D. Friedman (now at Morristown Memorial Hospital in New Jersey) and his former colleagues at St. Barnabas Medical Center in Livingston, N.J. In a review of breast MRI, the authors said that bilateral imaging should be the standard technique.

The researchers use the sensitivity-encoding parallel imaging technique combined with sequences such as turbo-spin echo and turbo-field echo to produce high-resolution images with short acquisition times. They have achieved speeds of 47 seconds per time point and spatial resolution between 1.2 and 1.4 mm² in plane and 1.5 mm through plane. They noted that parallel imaging reduces motion and fold-over artifacts.

They said that bilateral imaging decreases the risk of misdiagnosis because it provides a more symmetric image, making interpretation easier. In addition, simultaneously imaging both breasts improves detection in patients who already have been diagnosed with cancer because lumps may appear larger or smaller at different times because of hormonal fluctuations. Bilateral imaging also eliminates interobserver variability because unilateral images may be interpreted by two radiologists.

More accurate diagnoses improve patient outcomes and reduce doctor liability. Furthermore, the researchers observed, doctors and patients prefer to have images of both breasts before making decisions, so bilateral imaging decreases the need for invasive procedures and follow-ups. (American Journal of Roentgenology, Aug. 1, 2006, pp. 345-349.)