Lower extremity MRI: are their requests always appropriate in France?

The primary aim is to assess current lower extremity MRI requests' relevance with a secondary focus on the knee.

Using data from the National Health Data System (SNDS), we conducted an observational study of adults (18+) who underwent lower extremity MRI between July 1 and December 31, 2021. This study included analyzing medical consultations and imaging procedures (particularly X-rays) in the 6 months before and after the index MRI, as well as medical procedures and hospitalizations related to knee procedures within 6 months post-MRI.

During the study period, 779,721 adults underwent lower extremity MRI, marking a 76% increase compared to a previous study conducted in 2012. General practitioners requested MRI in 70.5% of cases, often as the primary imaging modality. Notably, 52.1% of patients had not undergone lower extremity X-rays in the 6 months preceding MRI, and 13% underwent at least two MRI examinations within a year. Focusing on the knee, most patients (80%) did not undergo any outpatient medical procedure or hospitalization involving the knee within the 6 months post MRI.

In France, lower extremity MRI, particularly knee MRI, is frequently used as a first-line imaging procedure, unlike what is recommended.

Question How often are requests for lower extremity MRI examinations appropriate? Findings Lower extremity MRI is often performed as a first-line imaging procedure, even though it is not recommended. Clinical relevance The study findings underscore the importance of disseminating guidelines regarding lower extremity MRI appropriateness to increase its availability for appropriate purposes, thereby improving patient care.