MRI of the foot and ankle: Diagnostic performance and patient acceptance of a dedicated low field MR scanner

✍ Scribed by Guido Verhoek; Marco Zanetti; Stefan Duewell; Hans Zollinger; Juerg Hodler

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 691 KB
• Volume: 8
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.1880080330

✦ Synopsis

Abstract

The objective of this study was to compare image quality and patient acceptance of a dedicated .2‐T MR system and a 1.0‐T whole body system. Forty‐one consecutive patients referred for MRI of the foot or ankle were prospectively examined with a dedicated .2‐T low field system and a 1.0‐T whole body system. Images were evaluated qualitatively by two observers and quantitatively using signal‐difference‐to‐noise ratios. The patients were interviewed with respect to positioning, examination time, noise, claustrophobia, confidence in the diagnosis, and willingness to repeat the examination, using a questionnaire. The qualitative score was significantly higher for the 1.0‐T system (2.6 vs 2.2 for reader 1 [P = .008] and 2.6 vs 1.7 for reader 2 [P < .0001]), respectively. The signal‐difference‐to‐noise ratios were also superior for the 1.0‐T MR system (2.96 vs .88, P < .0001). However, 96% of the lesions visualized at 1.0 T were also detected with the low field system. Patient acceptance was significantly better for the 1.0‐T MR scanner (48.6 vs 43.9, P = .007). Image quality of the dedicated low field system was inferior to the 1.0‐T system using objective parameters, and patients did not prefer the low field system. Although only 4% of lesions were missed in this series, the low field MR system can only be recommended when funding is limited and the available space is limited.