What benefit does magnetisation transfer provide in MR angiography?

Magnetisation transfer is a technique used in MR angiography that enhances the contrast between flowing blood and surrounding static tissues. The principle behind this benefit lies in the interaction between protons in moving blood and those in surrounding tissues. When the magnetic resonance signals from the moving protons are selectively enhanced through a magnetisation transfer effect, a clearer distinction is created between the blood vessels and the static tissues. This improved contrast is particularly beneficial in visualizing vascular structures, as it helps in differentiating between the flowing blood and adjacent tissues, which can sometimes appear similar in standard MR imaging.

The other choices, while they reflect certain aspects of MRI, do not correctly pinpoint the specific advantage provided by magnetisation transfer in the context of MR angiography. For instance, increased visibility of fatty tissues is not directly related to the aims of magnetisation transfer in this context. Enhanced resolution of static tissues or reduction of background noise, while important in imaging, do not address the primary purpose of magnetisation transfer, which is to improve the visualization of blood flow specifically in angiographic studies.