• Ultra-high field MRI of the knee

Objective This study aims at evaluating subjective tolerance and short-term side-effects related to ultra-high field (UHF) knee magnetic resonance imaging (MRI) examination at 7T in healthy volunteers and patients with osteoarthritis.
Methods Forty-one subjects were enrolled: 21 healthy volunteers, and 20 patients with osteoarthritis.
After each exam, all subjects were asked to fill out a form about short term side effects, and to compare the experience with previous MR exams. The form was divided in two parts: the first about the dynamic phase of the exam and the second about the static phase.
Mann-Whitney test was used to compare results between healthy volunteers and patients, and between males and females.
Results The exam was considered comfortable enough in 98% of subjects, and 94% of them would perform it again, if required. No exam was interrupted.
At least one side-effect was reported in 41% of the exams during the dynamic phase, and in 49% during the static phase.
The most common side-effect reported was dizziness.
No statistically significant differences were observed between healthy volunteers and patients, and between males and females.
Conclusions Knee UHF MR is a tolerable procedure both in subjects and patients, comparable to lower field MR exams and safe enough to be performed in the clinical practice. The total score of side effects reported decreased gradually over time mainly due to the experience of the radiological team.