Final answer:
SNR in MRI measures how clearly the signal is distinguished from background noise, affecting image clarity and diagnostic accuracy. Improved SNR enhances scanner resolution and contrast, but image distortion can decrease SNR. The main disadvantages of MRI scans are their high cost and the need for strong magnetic field shielding.
Step-by-step explanation:
Signal-to-Noise Ratio (SNR) in MRI is an important aspect concerning the quality and diagnostic value of MRI images. Here are four facts about SNR in MRI:
- SNR is a measure of the level of desired signal compared to the level of background noise. A higher SNR indicates a clearer image, making it easier to diagnose medical conditions accurately.
- The resolution of an MRI scanner is directly related to the SNR; better SNR typically means higher scanner resolution and finer details can be discerned in the images.
- Various techniques, such as the use of contrast enhancement agents, are employed to improve SNR and MRI image quality by increasing the contrast between different tissues, making abnormalities more noticeable.
- Factors such as patient movement, hardware imperfections, and magnetic field inhomogeneities can lead to image distortion which inversely affects the SNR.
As for the disadvantages of MRI scans, high cost and the need for shielding from magnetic signals are two major drawbacks, making access to this advanced imaging technique somewhat limited.