MRI found to improve breast cancer detection

A new MRI can provide more effective breast cancer screening than previous methods, found a study conducted on UT's Health Science Campus.

The results, discovered by Associate Professor of Radiology Haitham Elsamaloty, show that a 3 tesla MRI detects breast cancer more frequently than traditional methods.

"Our study demonstrates that 3T MRI is an important adjunct to mammography and sonography," Elsamaloty said.

The study included 434 women who underwent 3T MRI evaluations of the breast, as well as the more common mammography and sonography evaluations.

The study concluded that 3 tesla MRI is 100 percent sensitive to abnormalities in the breast, while mammography is only 81.1 percent sensitive and sonography is 86.4 percent sensitive.

"3T MRI also depicted a significantly higher number of malignant tumors in the breast than mammography or sonography," Elsamaloty said.

MRI machines have different strengths, said Judy Case, the MRI nuclear medicine manager at UT's Medical Center.

"Tesla is the measure of strength of the MRI. All MRI are categorized by strength, and 3T designates a strength of 3 tesla. The normal MRI machine that most facilities use now only has a strength of 1.5 tesla," Case said.

The higher magnetic field strength of the 3T MRI improves the "signal to noise ratio" and allows for faster data collection, Elsamaloty said.

"This is very important in evaluation of breast tumors and leads to an overall improved image of tumors and diagnostic image quality," he said.

When patients go in for MRIs, they are put in a magnetic machine, feet first, Case said. The machine lines up the hydrogen atoms in the body and gives off a signal if anything is detected, she said.

"When you go into the magnetic field, the tube has a north and south pole. Once you're in the magnetic field, the hydrogen atoms line up accordingly with the north and south pole magnets. Then the atoms flip 90 degrees when the radio frequency goes off. When the atoms do that, they give off a signal and give the image," she said.

"We have the person lie on their stomach, and there is a cradle that the breasts lie in. The thing that holds them is the receiver, which picks up the signal from the magnetic scanner," she said.

There are some complications and dangers that medical staff has to look out for when doing an MRI procedure, Case said.

She said before a patient goes into the scanner, the medical team goes through a checklist to make sure patients do not have any splinters of metal in their bodies that may cause them damage while they are under the magnetic field.

"Depending on their age, we do a screening of the kidneys to make sure they don't have any type of metal they have in them that they didn't tell us about," she said.

This form of detection may also be a problem for patients who are claustrophobic, Case said.

Though 3T MRI is a more effective method of detecting breast cancer, Elsamaloty said, mammograms and sonograms continue to be a widely used method.

"Mammography remains the gold standard screening modality, as it is widely available and is a low cost technique with good sensitivity and specificity. MRI is a high cost modality and, therefore, is used in screening high risk patients," he said.

UT's Medical Center does have the lower strength 1.5T MRI machine, but Case said they are starting to use 3T MRI because it gives more detail due to the strength of the magnet.