Brain cancer patients need enhanced MRI examination

MRI examinations can be divided into plain scan and enhanced scan. The difference between the two is that the former does not require the injection of contrast agent, while the latter requires the injection of contrast agent before the examination. For patients suspected of brain cancer, doctors generally recommend enhanced MRI examinations.

Magnetic resonance imaging mainly uses the principle that human tissue, including tumor tissue, emits magnetic field signals. However, since the magnetic field signals emitted by tumor tissue are not much different from those of normal brain tissue, contrast agents need to be injected to improve the recognition rate of tumors.

The characteristic of tumors is that they are rich in new blood vessels, and it is these new blood vessels that provide blood supply for tumor growth. The walls of new blood vessels are different from normal blood vessels, which is their unique feature. During enhanced MRI examinations, contrast agents enter these new blood vessels and then extravasate into the tumor tissues they supply, thereby outlining the contours of the tumor on the developed MRI images.

Generally speaking, tumors that are significantly enhanced after contrast agent injection usually have a rich blood supply. However, this is not absolute. Some tumors can hardly be enhanced, but their blood supply is also rich. This is because whether the enhancement is obvious depends not only on the number of new blood vessels in the tumor, but also on the quality of the new blood vessels. Some new blood vessels are of better quality, and their vascular walls have poor permeability, so contrast agents cannot penetrate. In this case, even if these tumors have a rich blood supply, they will not be significantly enhanced on MRI.