Algorithm reduces radiation dose for molecular breast imaging

A new image-processing algorithm can reduce the necessary radiation dose for patients undergoing molecular breast imaging exams, reported authors of a recent study published in the American Journal of Roentgenology.

Lesions that were imaged using the new method required half the standard dose and produced scans comparable, and even better than traditional MBI exams, Ashley T. Tao, with Mayo Clinic’s Department of Radiology, and colleagues wrote. What’s more, the algorithm can reduce imaging time and improve the patient experience.

MBI exams use gamma cameras to measure the uptake of 99mTc-sestamibi in a patient’s breast. Prior research has shown the method can detect more occult breast cancers compared to mammography, but radiation levels remain a concern, even despite some success in lowering patient dosage.

“Despite the promising results, concern about the higher radiation dose of MBI relative to mammography persists and is a critical barrier to widespread acceptance of MBI for screening,” Tao and colleagues wrote.

The researchers compared images from the standard dose MBI exams of 50 patients at 300 Megabecquerel (MBq) 99mTc-sestamibi. Two breast radiologists compared their ability to visualize lesions on standard-dose images, half-dose images and algorithm-processed half-dose images.

Overall, images taken using the algorithm and at one-half the standard dose were “equivalent or better without comprise of image quality” compared to standard-dose images.

“When the relative noise level of the half-dose images was matched to that of the standard-dose images (default-filtered half-dose versus standard-dose), there was no difference in reader preference, suggesting that the image-processing algorithm software did not negatively affect or artificially enhance the half-dose images' lesion conspicuity,” the researchers wrote.

Additionally, Tao et al. suggested the algorithm could cut the typical 40-minute image time required for MBI exams, which would likely improve patient satisfaction and increase MBI usage.

“Thus, strategies to maintain diagnostic accuracy of MBI at reduced image counts by reducing administered activity, image acquisition time, or both, may generate more widespread acceptance of MBI,” the authors concluded.