Elastography improves ultrasound
specificity and enables more precise mapping of tumors
Elastography is an effective, convenient technique that,
when added to breast ultrasound, helps distinguish cancerous breast lesions from
benign results, according to an ongoing study presented today at the annual meeting
of the Radiological Society of North America (RSNA).
When mammography yields suspicious findings, physicians
often use ultrasound to obtain additional information. However, ultrasound has
the potential to result in more biopsies because of its relatively low specificity,
or inability to accurately distinguish cancerous lesions from benign ones. Approximately
80 percent of breast lesions biopsied turn out to be benign, according to the
American Cancer Society.
"There's a lot of room to improve specificity with ultrasound,
and elastography can help us do that," said the study's lead author, Stamatia
V. Destounis, M.D., a diagnostic radiologist at Elizabeth Wende Breast Care, a
large, community based breast imaging center in Rochester, NY. "It's an easy way
to eliminate needle biopsy for something that's probably benign.
Elastography improves ultrasound's specificity by utilizing
conventional ultrasound imaging to measure the compressibility and mechanical
properties of a lesion. Since cancerous tumors tend to be stiffer than surrounding
healthy tissue or cysts, a more compressible lesion on elastography is less likely
to be malignant.
"You can perform elastography at the same time as handheld
ultrasound and view the images on a split screen, with the two-dimensional ultrasound
image on the left and the elastography image on the right," Dr. Destounis said.
As part of the ongoing study, 179 patients underwent
breast ultrasound and elastography. The research team obtained 184 elastograms
and performed biopsies on all solid lesions. Of 134 biopsies, 56 revealed cancer.
Elastography properly identified 98 percent of lesions that had malignant findings
on biopsy, and 82 percent of lesions that turned out to be benign. Elastography
was also more accurate than ultrasound in gauging the size of the lesions.
"Ultrasound can underestimate the true size of lesions,
as it only sees the actual mass and not the surrounding changes the mass may cause,"
Dr. Destounis said.
Coauthors are Andrea L. Arieno, B.S., Melissa N. Skolny,
M.S., Renee Morgan, R.T., Patricia Somerville, M.D., and Philip F. Murphy, M.D.
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