Study co-author Adam Waldman, Ph.D., M.R.C.P., F.R.C.R., consultant neuroradiologist and imaging research director at Imperial College NHS Trust and honorary senior lecturer at Imperial College and University College, London and his colleagues find perfusion MRI shows changes in blood volume in the brain that often come before brain tumors turn cancerous. It is able to spot these changes a year or more before other markers of brain cancer can be found.
Low-grade gliomas, primary brain tumors, grow slowly over years. Most turn into high-grade gliomas, which have a poor prognosis. Brain tumors can lead to angiogenesis -- the formation of new blood vessels. These abnormal vessels mean changes in blood volume and flow.
For the study, 13 patients with low-grade gliomas had perfusion MRI and contrast-enhanced MRI every six months for up to three years. Researchers wanted to see whether changes in relative cerebral blood volume (rCBV) will indicate future cancer.
Results revealed that patients with tumor transformation, the mean rCBV increased from 1.94 at the beginning of the study to 3.14 12 months before the transformation to 3.65 six months before the transformation and to 5.36 when the transformation was diagnosed.
Significant changes in rCBV are an important marker of malignant change in gliomas and indicate the earliest stages of the transformation process, the study suggests. The study also shows perfusion MRI can detect these changes long before the traditional contrast-enhanced MR images can.
The new study is published in the April issue of the journal Radiology.
