Helping radiologists identify structural sacroiliac joint lesions in CT scans acquired for other clinical indications.
Supporting radiologists in reporting structural joint findings that might otherwise go unreported
Addressing the burden of undetected structural joint damage
Intended purpose
RFMaple is medical device software intended for use by qualified radiologists as a concurrent reading aid. It analyses the axial series of CT studies of adults aged 18 to 60 in which the sacroiliac joints are imaged, and highlights regions of interest containing the structural bone lesion types erosion and ankylosis. RFMaple does not provide a diagnosis, is not intended for triage, and does not replace review by, or the clinical judgment of, a qualified radiologist. It is not indicated for studies in which sacroiliac joint anatomy is substantially altered, including congenital malformations, post-surgical alterations and severe acquired deformities.
Regulatory status
RFMaple is under development. It is not CE marked under Regulation (EU) 2017/745 in the European Union. It has not been cleared by the U.S. Food and Drug Administration in the United States.
Manufacturer
RheumaFinder BV, Vlasgaardstraat 52, 9000 Ghent, Belgium. SRN BE-MF-000040625. Basic UDI-DI 54199805451RFPR76.
RFMaple is an AI-powered application that analyses CT images for structural bone lesions of the sacroiliac joints
Developed for the incidental detection of clinically relevant structural sacroiliac joint lesions in CT studies performed for other clinical indications, without requiring additional imaging, RFMaple assists radiologists in detecting structural bone lesions (erosion and ankylosis) in the sacroiliac joint region.
RFMaple is intended to help radiologists identify structural joint damage that might otherwise go unreported in routine practice. In a retrospective reader comparison study on 1,625 evaluable patients, structural sacroiliac joint lesions confirmed by expert reference readers were identified in 82% of cases with RFMaple, compared with 5% in the corresponding routine radiology reports.
RFMaple provides a second read that the radiologist reviews alongside the original images. Cloud native and PACS-agnostic, RFMaple is designed as an add-on application to any type of PACS, supporting higher incidental pickup rates of clinically relevant structural sacroiliac joint lesions.


Incidental detection of clinically relevant structural sacroiliac joint lesions in CT imaging
Artificial intelligence can be used to support the detection of structural bone lesions (erosion and ankylosis) in the sacroiliac joint region, providing the reporting radiologist with an additional layer of image interpretation.
Frequently, in medical images obtained for other diagnostic questions, incidental findings are present. Despite being detectable in the images, they are often not picked up due to their subtle appearance and, above all, time constraints in clinical practice. AI can support radiologists in identifying these findings as a concurrent second read.
AI is being used in radiology in a number of ways today. For the most effective use of AI, it is necessary to coordinate the input of high-quality expert-labelled medical images and algorithm development between physicians and computer scientists. These use cases can solve increasingly challenging problems in clinical practice. This (r)evolution in imaging depends on applying powerful AI tools to clinical problems in the best possible ways, i.e., the successful development of AI use cases.
Incidental detection of structural sacroiliac joint lesions gives the radiologist information that may be relevant to the further diagnostic work-up of the patient
RFMaple is an AI-powered add-on to the PACS that assists radiologists in detecting the structural bone lesion types erosion and ankylosis in the sacroiliac joint region, as incidental findings in CT examinations performed for other diagnostic questions. These lesions may be associated with inflammatory or non-inflammatory arthropathies.
RFMaple uses deep learning to analyse CT images for structural bone lesions. In a standalone performance study on 2,247 analysed anonymised CT studies, RFMaple achieved a patient-level sensitivity of 89% (95% CI 86–92%) and a specificity of 94% (95% CI 92–95%) for the detection of structural sacroiliac joint lesions, against a reference standard established by expert radiologist readers. Lesion-specific performance was 81% sensitivity and 95% specificity for erosion, and 90% sensitivity and 98% specificity for ankylosis.
RFMaple is designed as a cloud-native add-on to any type of PACS, to be offered as software-as-a-service on a pay-per-use model. Performance has been assessed in a standalone performance study and a retrospective reader comparison study; results are summarised in the clinical evaluation. The software is designed to support customers’ obligations under the GDPR, and to support HIPAA-covered entities in the United States.

Patient journey
Structural sacroiliac joint lesions are visible on large numbers of CT studies performed each year for unrelated indications
Published literature describes substantial disease burden, diagnostic delay and healthcare cost associated with (non-)inflammatory arthropathies. RFMaple is intended to increase the reporting of structural sacroiliac joint lesions on CT studies performed for other indications. Its effect on patient outcomes, healthcare costs and therapeutic decision-making has not been established and is planned to be assessed as part of post-market clinical follow-up.
News
Intended purpose and regulatory status: see top of page.










