What determines in-plane resolution in MRI?

In-plane resolution in MRI is primarily determined by the field of view (FOV) divided by the matrix size. The FOV refers to the spatial extent of the image being captured, while the matrix size indicates how many pixels (or individual data points) are used to represent the image within that field. By dividing the FOV by the matrix size, one can calculate the pixel size or the resolution in each plane of the image. A smaller pixel size typically results in greater detail and clarity in the final image, which is essential for accurately interpreting anatomical structures and any potential pathologies.

The other factors mentioned in the other options, such as slice thickness, echo time, magnetic field strength, patient weight, or the combination of repetition time (TR) and echo time (TE), contribute to various aspects of MRI image quality, such as contrast, signal-to-noise ratio, or specific imaging characteristics, but they do not directly determine in-plane resolution. In-plane resolution specifically hinges on how finely the anatomy can be delineated within the chosen FOV.