What is t-wave artefact and how does it occur?

T-wave artefact is specifically linked to the interaction of magnetic fields with the electrical potentials generated by the body. It occurs when blood flows through a magnetic field, inducing a changing electrical signal. This artefact is most commonly observed in cardiac MRI scans, where the presence of the magnetic field can interfere with the normal electrical activity of the heart, resulting in distortions in the image.

The correct answer highlights the fundamental physics behind the artefact, illustrating how the flow of conductive blood generates an electrical potential that contributes to artefacts in the imaging process. This understanding is crucial for radiographers and MRI technicians to identify and mitigate such artefacts, ensuring better quality images and more accurate diagnoses. Other options suggest unrelated physiological phenomena or conditions that do not involve the fundamental interaction of cardiac electrical activity and external magnetic fields, thereby failing to accurately explain the cause of T-wave artefacts.