Researchers at Johns Hopkins say that combining various
types of magnetic resonance imaging techniques more
accurately sorts cancers from benign masses in breast
tissues than any single imaging techniques. Their findings
are presented in the October issue of Radiology.
Magnetic resonance imaging scanners can be calibrated to
take images that highlight a specific type of human tissue.
For example, so-called T1-weighted imaging sequences are
best at imaging fatty tissues, while T2-weighted sequences
best show fluids, like those found inside cysts.
Additionally, three-dimensional MR imaging can help define
the size and shape of tumors. Contrast agents, dyes
injected into patients prior to imaging to concentrate in
the tumor and make it more visible, further enhance MR
images similar to the way dye in water helps highlight the
"veins" in celery stalks.
In their study, Hopkins researchers combined T1, T2 and 3-D
imaging techniques, with and without contrast agents, on 36
subjects. Eighteen already had been diagnosed with benign
breast lesions and 18 with breast cancer. The researchers
reviewed the results of the combined images without knowing
which images came from which patient.
The combined, or multiparametric, MRI technique was able to
identify and characterize breast lesion tissue clusters in
all 36 patients, revealing which were benign and which were
malignant. In addition, the multiparametric technique was
even more powerful when used with contrast agents,
providing more precise differentiation between the
cancerous and noncancerous tissue than the same images
without contrast.
"Each individual imaging modality has its advantages," said
Michael Jacobs, the lead researcher for the study at the
Hopkins Department of
Radiology. "When all these techniques are combined into
one data set, you can achieve an approach that shows the
characteristics of a lesion not normally available using
just one imaging technique."
Jacobs noted that while his study appears to demonstrate
the feasibility of using a combined imaging approach to
identify breast tumors, larger studies are needed to
determine if the approach might be useful for studying the
molecular dynamics of breast cancer tumors.
"It's known that certain compounds, such as choline and
sodium ions, tend to concentrate in cancer cells," Jacobs
said. "We are now investigating whether multiparametric MR
imaging might be effective in imaging intracellular
compounds within breast tumors. If so, this will enable a
comprehensive assessment of the tumor environment."
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