Rapid Knee MRI Scanning May Soon Be Attainable

Simultaneous multislice (SMS) and parallel imaging (PI) acceleration can reduce the time needed to acquire a knee magnetic resonance imaging (MRI) scan to less than five minutes, according to a new study.

Researchers at the Johns Hopkins University School of Medicine (JHU-SOM; Baltimore, MD, USA), Ospedale Regionale di Lugano (Switzerland), and other institutions conducted a study between April 2018 and October 2019 involving 252 adult patients (mean age 47 years; 134 men) presenting with painful knee conditions. All participants underwent fourfold SMS-PI–accelerated, 5-minute, turbo spin-echo (TSE) knee MRI and standard-of-care twofold PI-accelerated, 10-minute, TSE knee MRI.


The patients were imaged on either a 1.5T scanner (104 patients) or a 3T scanner (148 patients). The MRI scans were then examined by three radiologists who evaluated them for meniscal, tendinous, ligamentous, and osseocartilaginous injuries. The results showed no statistically significant differences between the 5-minute and 10-minute protocols, indicating they performed equivalently across knee conditions and magnet strengths. The study was published on April 6, 2021, in Radiology.

“This technique is the only one currently available for clinical use that can reduce acquisition times sufficiently to perform a complete knee examination in five minutes, while providing similar diagnostic performance and without reducing the image resolution or compromising image quality,” wrote Naveen Subhas, MD, of the Cleveland Clinic in (OH, USA), in an accompanying commentary. “This study brings us one step closer to establishing a new normal: the five minute knee MRI.”

A knee MRI is an accurate tool for demonstrating fluid collections in and outside the knee joint, soft tissue swelling, and swelling within the bone itself that may be the result of a bone bruise or stress fracture. Loose fragments of cartilage or bone within the joint are also readily seen.

Related Links:
Johns Hopkins University School of Medicine
Ospedale Regionale di Lugano