Basics: What is an MR Spectroscopy?
MR Spectroscopy (MRS): Approved for use in the United States in 1995, MRS is a noninvasive method, which provides actual metabolic information about brain tissue. It enables tissue characterization on a biochemical level, which cannot be achieved with traditional MRI. MR spectroscopy can also detect pathologies that are invisible to traditional MRI imagine, even at 3T, because metabolic abnormalities often precede structural changes. MRS does not replace conventional MRI studies, but is used as a complimentary study.
Answers to commonly asked questions about MR Spectroscopy:
What are some of the more common reasons to order MR spectroscopy?
- To see if a mass or lesion is cancer versus something else, like infection, or dead brain from a stroke.
- To differentiate tumor recurrence, versus “Post radiation necrosis”.
- To sometimes differentiate between different types of tumors.
- To differentiate between patients with Alzheimer’s disease non-Alzheimer’s dementia.
Discussion of images above:
The above pictures show both standard MRI images of a patient’s brain, as well as an MR spectroscopy graph. The patient has a probable brain tumor, just above the olfactory nerves, which brings the brain input about smell. What MR spectroscopy does, is tell us whether it is a tumor or not, and whether the tumor most likely arose in the brain, or came from somewhere else in the body. In addition, with this patient, we were actually able to decipher the actual type of brain tumor. This tumor turns out to be something called a “Meningioma”, as it arises from the lining of the brain, the meninges. Meningiomas contain a unique metabolite “alanine”, that let’s us specify its exact tumor type. This is important for treatment planning, including whether it could be followed, removed surgically, or might respond well to radiation treatment, instead of surgery.