Spatial resolution: pixel/voxel size, FOV, matrix, focal spot & sampling
A line-pair (bar) test pattern with bars getting finer left to right; low frequencies resolve as sharp black bars, but past a limiting frequency the bars blur and merge into uniform grey. Spatial frequency is labelled in line pairs per mm. A lower panel shows that a pixel grid must place at least two samples per line pair, giving the Nyquist limit fN equals one over two times the pixel size. A second lower panel shows a finite focal spot casting a penumbra past an object edge onto the detector, with magnification equals source-to-image distance over source-to-object distance, and edge blur Ug approximately equals focal-spot size times object-to-image distance over source-to-object distance.
Practice the Physics paper
FRCRX is a Part 1 Physics question bank: true/false items with explanations, timed mocks and topic analytics.