"The magic angle is an MRI artifact that occurs in sequences with a short TE (less than 32 ms) - T1 weighted, proton density weighted, and gradient echo sequences."
"When molecules lie at 54.74°, there is lengthening of T2 times with corresponding increase in signal. Thus in short TE sequences, the T2 signal does not decay significantly before the scanner picks up the signal. On the other hand, in long TE sequences (like T2 weighted sequences), by the time the scanner picks up the signal, the T2 signal has already decayed."
"When molecules lie at 54.74°, there is lengthening of T2 times with corresponding increase in signal. Thus in short TE sequences, the T2 signal does not decay significantly before the scanner picks up the signal. On the other hand, in long TE sequences (like T2 weighted sequences), by the time the scanner picks up the signal, the T2 signal has already decayed."
"It only occurs in short TE sequences (e.g. T1, PD, GRE). Sequences with a longer TE (e.g. T2) can be used to avoid this artifact."
"It only occurs in short TE sequences (e.g. T1, PD, GRE). Sequences with a longer TE (e.g. T2) can be used to avoid this artifact."
"Other non-pathological causes of high signal within tendons include near tendon insertions and/or where the tendon normally fans out or merges with other tendons."
Expected headings
"Normal"
"Artifact"
"Remedy"