Ultrasound versus low-field magnetic resonance imaging in rheumatic diseases: a systematic literature review

Objective: US and MRI play a signifi -cant role in the diagnosis of rheumatic diseases and in monitoring treatment response. This systematic review summarises and evaluates available evidence on the value of low-field MRI compared to US in rheumatic diseases. Methods: A computerised literature search was conducted by a single reviewer to identify relevant published articles on the diagnostic accuracy of low-field MRI compared to US in rheumatic diseases. The literature search comprised the period from January 1998 to September 2013. Results: The search yielded a total of 1055 articles that were reviewed by title or abstract; finally, 23 articles fulfi lling all inclusion criteria were included in the analysis. Our results show that low-field MRI is probably more sensitive than US in the detection of erosions, due to its higher multiplanar capacity. In OA there was a good correlation between US and MRI measurements for cartilage thickness and for effusion in the superior and in the lateral recesses. Conclusion: There are still few studies comparing US and low-field MRI for their diagnostic and prognostic value in rheumatology and it is currently difficult to draw any firm conclusions on the preferred imaging technique to answer specific clinical questions.