Reader Experience, Image Type Affects Diagnostic Accuracy in axSpA Imaging

Accuracy in assessing imaging findings for the diagnosis of axial spondyloarthritis (axSpA) depends on the reader’s experience as well as the imaging modality used, according to a study published online in RMD Open.

“This underlines the importance of continuous training of young and inexperienced radiologists in the field of axSpA imaging using established and new methods,” wrote corresponding author Sevtap Tugce Ulas, MD, of the Charité Universitätsmedizin Berlin Campus Charité Mitte, Berlin, Germany, and study coauthors. “Our results make a crucial contribution to overcoming existing shortcomings, as our findings reveal that, besides the experience of the reader itself, it is the choice of modality that has an important impact on overall diagnostic accuracy.”

To investigate differences in diagnostic accuracy by reader experience, researchers had 9 readers score X-ray, magnetic resonance imaging (MRI), and computed tomography (CT) of sacroiliac joints for the presence or absence of axSpA. Readers were divided into 3 groups based on their experience. An inexperienced group included 3 medical research students with a year or less of experience. A semiexperienced group included 3 radiologists with up to 8 years’ experience. An experienced group included 2 radiologists and a senior rheumatologist with up to 17 years’ experience in musculoskeletal imaging.

The study included images for a total 163 patients with low back pain. Prior to the reading sessions, an experienced rheumatologist determined 89 of the patients had axSpA. The remaining 74 were diagnosed with mechanical, degenerative, or nonspecific low back pain.

Across imaging modalities, the most experienced group had the highest diagnostic performance, according to the study, with the exception of X-ray, for which accuracy was slightly higher in the semiexperienced group. Diagnostic accuracy for the inexperienced and semiexperienced groups was highest when CT was combined with MRI: 78.5% in the inexperienced group and 85.3% in the semiexperienced group.

“Interestingly, this combined modality approach had no additive value for the 3 highly experienced readers,” researchers wrote, “suggesting that the benefits of adding CT are more pronounced in readers with less experience.”

Meanwhile, the experienced group had the highest diagnostic accuracy with MRI: 85.9%. Differences in diagnostic accuracy were most significant for MRI between the experienced group and the inexperienced group (85.9% vs 76.1%), the study found.

“MRI requires more experience, while CT is more suitable for inexperienced radiologists,” researchers wrote. “However, diagnosis relies on both clinical and imaging information.”

Reference

Radny F, Ziegeler K, Eshed I, et al. Learning imaging in axial spondyloarthritis: more than just a matter of experience. RMD Open. 2024;10(1):e003944. doi:10.1136/rmdopen-2023-003944