MRI for brain tumours: how does it work?

Magnetic Resonance Imaging (MRI), is a non-invasive medical imaging technique that uses powerful magnets and radio waves to generate detailed images of the body's internal structures, and is an integral method for assessing brain tumours. Revered neuroradiologist Professor Sotirios Bisdas explains how MRIs are used to diagnose brain tumours, the difference between malignant and benign tumours, and how MRI results can affect treatment plans.

How does an MRI help in diagnosing brain tumours, and what information does it provide about their nature?

An MRI, which stands for Magnetic Resonance Imaging, is like a superhero when it comes to finding brain tumours. MRI works by using strong magnets and radio waves to take detailed pictures of your brain, creating images of your brain in different slices and planes to pinpoint the exact location of the tumour.

It is essential to know the location of the tumour, in devising optimal treatment strategies that minimise damage to healthy brain tissue. MRI is an essential tool for closely monitoring lesions, accurately measuring tumour size, and tracking changes in growth over time. It plays a critical role in providing valuable information about a tumour's characteristics, helping doctors differentiate between benign and malignant growths. This distinction is crucial, as treatment plans differ greatly depending on the type of tumour. MRI can also reveal essential details about blood flow and metabolic activity within the tumour, assisting doctors in creating personalised treatment plans, such as chemotherapy or radiation.

What are the specific features or characteristics between a malignant and benign brain tumour on an MRI scan?

Using MRI scans, neuroradiologists can distinguish between malignant (cancerous) and benign (non-cancerous) brain tumours based on their appearance and functional characteristics. Malignant tumours typically exhibit a chaotic appearance with irregular edges and areas of "contrast enhancement," indicating increased blood flow associated with rapid growth and invasion of surrounding healthy brain tissue. These tumours display heightened metabolic activity, consuming elevated levels of glucose and amino acids.

In contrast, benign tumours often present as well-organised with smooth, round edges and typically lack contrast enhancement. They tend to grow slowly and do not invade nearby areas. It's important to note that both malignant and benign brain tumours are treatable.

How is an MRI used to determine the stage or extent of a brain tumour?

Imagine your brain as a puzzle, and a brain tumour as a piece that doesn't quite fit. An anatomical MRI is like taking a high-resolution picture of that puzzle. It helps doctors in assessing the tumour's size and precise location, akin to pinpointing that odd puzzle piece.

An anatomical or structural MRI can reveal the precise boundaries of a tumour and determine whether it is localised or spreading to surrounding regions of the brain. Clearly defined edges indicate that the tumour is contained, while blurred edges could indicate that it is trying to infiltrate the healthy brain.

A functional MRI helps experts such as neuroradiologists see if the tumour is affecting any important brain functions like speech, movement, or memory. If certain brain areas are impacted, they can plan your treatment more precisely. Additionally, functional MRI enables tracking of changes over time, facilitating doctors in adjusting their strategies to accommodate new developments. By integrating information from both types of MRI, neuroradiologists generate a comprehensive understanding, akin to possessing a detailed map of the brain's structure alongside a live feed of its internal dynamics. This comprehensive insight helps them understand the stage or extent of the brain tumour in a more detailed manner.

Can an MRI accurately identify the type of brain tumour, and how does this information impact treatment decisions?

A state-of-the-art MRI exam boasts exceptional accuracy in identifying the type of brain tumour based on its characteristics and metabolic activity. However, there may be instances where additional tests, such as a biopsy (a small sample of the tumour), are required to definitively determine the type. Once the specific type of brain tumour is determined, it equips us with a roadmap to strategise our approach to combating it. Each tumour type presents a unique puzzle, necessitating a tailored solution.

MRI aids in selecting the appropriate tools and strategies to tackle each puzzle effectively, whether through surgery, radiation, chemotherapy, or a combination of treatments. Our goal is to select the most effective treatment, tailored to the specific tumour type. Furthermore, MRI facilitates monitoring the treatment's efficacy over time, ensuring we remain on the right path toward combating the tumour.

If you are suffering from a brain tumour and would like to book a consultation with Professor Bisdas, do not hesitate to do so by visiting his Top Doctors profile today.