Table 2.

The most frequent cause of image quality degradation based on the survey. These were the input errors introduced to intentionally degrade MR images of the large geometric accuracy and ACR phantoms.

Simulated provocations	Expected image quality parameter to be affected	Mode of detection
B0 field inhomogeneity	Slice position and Geometric accuracy	Distortion measurements and ACR Slice position test
40 mm metallic paper clip in magnet’s bore ∗
Coil-related	image uniformity and SNR	ACR PIU and SNR measurements
No image intensity correction◦
Coil failure
Gradient nonlinearity•	Geometric accuracy	Distortion measurements
No 2D/3D gradient
nonlinearity correction
External electrical interference	SNR image uniformity	SNR Spike artifacts and ACR PIU test
Static electric discharges/sparks ◦

PIU – Percent image uniformity; SNR – signal-to-noise ratio.

^∗Both phantoms.

^◦ACR phantom only.

^•Large FoV geometric accuracy phantom only.