Study outlines ways to cut-down number of knee MRI scans

Overuse of medical imaging increases the cost of healthcare and also poses a risk for the patients. A recent study published in the Journal of American College of Radiology has suggested a few ways which may cut down the number of Magnetic Resonance Imaging (MRI) scans for knee injuries.

According to the study, a standardized reporting template, a grading system to determine injury severity, and clinician education are three elements which are needed to achieve the same.

The researches from UT Southwestern Medical Center in Dallas randomly selected a consecutive series of 292 knee Magnetic Resonance Imaging scans from a pool of 882 studies (33%) performed during the first 6 months of 2017.

The reports from these studies were evaluated by a musculoskeletal (MSK) imaging fellow to determine whether there were severe degenerative changes, defined as high-grade or full thickness cartilage loss on both sides of the joint over an area of at least 1 cm or more.

Twenty per cent of these studies were also reviewed by an MSK fellowship-trained radiology attending physician for quality control purposes.

A second musculoskeletal radiologist, blinded to the Magnetic Resonance Imaging (MRI) results, evaluated corresponding knee x-rays, which were taken within six months of the MRI.

By August 2017, the facility implemented the five-point Kellgren-Lawrence (KL) grading scale to rate the degree of osteoarthritis. Grade 0 indicates no evidence of osteoarthritis on x-rays, while grade 4 indicates severe sclerosis and bone deformity.

With KL grades 3 or 4 on x-ray, clinicians typically do not recommend a follow-up Magnetic Resonance Imaging(MRI) to confirm results, as the diagnosis seems clear.

The second reader inserted the KL grade 3 or 4 scores from the knee x-rays into newly adopted structured reporting templates with recommendations for follow-up.

The facility then held monthly educational meetings for its musculoskeletal staff for presentations on how the KL grading system worked and how physicians could save hospital resources by avoiding follow-up MRI scans when x-rays showed osteoarthritis at KL grades 3 and 4.

The initiative succeeded. Prior to the program's start, 55% of MRI scans performed were on patients with KL scores of 3 or 4. After the improvement program was implemented, from October 2017 to February 2018, the frequency of knee MRI scans decreased significantly to 30% (p < .001). In addition, 80% of knee MRI scans corresponded with x-ray KL scores, which further reinforced the lack of need for follow-up MRI.

The authors concluded that the implementation of a standardized reporting template for knee x-rays with auto-populated KL grading focused clinician education are effective ways to decrease the repeated knee MRI scans.