Magnetic resonance imaging (MRI) of the breast is often performed before patients go through lumpectomy, the surgical removal of cancer or other abnormal tissue from the breast.

MRI scans give surgeons an idea of the size, shape and location of the patient's tumor prior to performing the breast-conserving surgery.

Findings of a new study, however, have shown that the patient's position during presurgical breast MRI may affect the accuracy of the scan, which could influence the success of tumor removal.

In a small study, researchers have found that MRI images taken prior to breast cancer surgery may give inaccurate data if the patient is positioned face down during the scan.

Patients who were placed face up during presurgical MRI, on the other hand, appear to have more detailed and accurate information that could result in the effective removal of the tumor.

For the study published in the journal Radiology on June 22, radiologists from Brigham and Women's Hospital in Boston involved 12 breast cancer patients who underwent lumpectomy, six of whom had MRI breast scans before and after surgery.

They found that patients who were laid face down during MRI had significant deformity on the scans of their breast and tumor position when compared with those whose scans were performed while they were lying on their back.

Based on the study's findings, the researchers said that surgeons may want to consider having their patients lie on their back during MRI breast scans.

"Accounting for change in size and shape caused by displacement and deformation of the tumor between standard imaging in the prone position and operative supine position, our analysis highlights that supine MRI before surgery may provide surgeons with more detailed and accurate information and could lead to effective tumor removal," said study researcher Dr.  Eva Gombos.

MRIs are notably performed while the patient lies face down but surgery is performed with the patient lying face up.

Kristin Byrne, a radiologist from Lenox Hill Hospital in New York City who reviewed the findings of the study, explained that this is so because when the patient lies on the back, the breasts tend to droop to the sides at different angles so they look different every time they are imaged, which can lead to misinterpretation.

Gombos said this has something to do with better quality images.

"This is because this results in better resolution and because a breast coil can be used, which leads to better quality images. Breasts are pendant-shaped, and the hanging down position allows a better visualization of the tissues close to the chest wall and armpit," Gombos said.