Magnetic resonance spectroscopy improves identification of cancerous
Oak Brook, Ill., USA. A study published in the August issue of Radiology
shows that adding spectroscopic analysis to magnetic resonance (MR) imaging
increased both the detection rate of cancerous tumours and the success rate
of distinguishing benign from malignant tumours.
MR imaging of the breasts has a high rate of sensitivity (94% – 100%) for
detecting tumours, but a variable rate of specificity (37% – 97%) for
distinguishing malignant from benign tumours. MR spectroscopy uses the same
magnet and electronics as MR imaging, but with specialized methods that
produce a "spectrum" identifying different chemical compounds in the
tissues. MR spectroscopy has been shown to be useful for looking at various
disorders, including cancer, Alzheimer's disease, diabetes and certain
inflammatory and ischemic diseases. Generally used for the brain,
spectroscopy poses no known health risk to patients and typically adds only
seven to 10 minutes to the MR procedure.
For the study, four radiologists evaluated 55 breast MR imaging cases
that had findings confirmed through earlier biopsies. The evaluations were
done with and without MR spectroscopy. The addition of spectroscopy resulted
in more cancerous tumours detected (from 87% to 94%), a higher success rate
for distinguishing benign from malignant tumours (from 51% to 57%) and a
greater agreement among the radiologists on their findings. Also, with the
addition of spectroscopic readings, two of the four radiologists had
significantly improved sensitivity to detect cancerous tumours and all four
participants achieved significantly improved accuracy in assigning a
probability of malignancy.
"Adding spectroscopy to breast MR examinations will not only reduce
concern over possible missed cancers and unnecessary biopsy procedures, it
may also improve the efficiency and quality of patient care," said co-author
Sina Meisamy, M.D., a postdoctoral fellow at the University of Minnesota
Center for Magnetic Resonance Research in Minneapolis.
"Spectroscopy gives us an additional piece of information about the
biochemical composition of the tumor," explained senior author Michael
Garwood, Ph.D., associate director of the Center for Magnetic Resonance
Research and the Lillian Quist – Joyce Henline Chair in Biomedical Research
Professor of Radiology at the University of Minnesota. "When the standard MR
imaging exam is inconclusive, the spectroscopy measurement can improve the
rate of detecting a cancerous breast tumor."
Radiological Society of North America:
The RSNA journal Radiology:
Center for Magnetic Resonance Research, University of Minnesota: