ASAS Recommendations for Requesting and Reporting Imaging in Patients with Suspected Axial Spondyloarthritis

Background: Clinicians face uncertainties in their daily practice when requesting imaging for patients with suspicion of axial spondyloarthritis (axSpA) or producing a report because requirements and desired information of the other disciplines is sometimes not completely known or understood.

Aim: This project aimed to develop easy-to-follow consensus recommendations for the standardized communication around imaging of sacroiliac joints and spine for diagnosis in patients with suspected axSpA or its management in clinical practice.

Methodology: A task force was established combining radiologists and rheumatologists from the Assessment of SpondyloArthritis international Society (ASAS), two members of young-ASAS and a patient representative. The task force defined the project’s aims and developed a project statement. Then, under the reflection of the literature and work of other groups, two survey rounds were designed, and all ASAS members invited to respond: first, to identify items for further consideration, second, to consider the detail of information to be transferred. Finally, ASAS members discussed the recommendations during the ASAS annual workshop in January 2022 and voted for the endorsement.

Results: The recommendations were endorsed by ASAS with approval from 73% of voting members. The final set of recommendation is presented in Figure 1. Six recommendations deal with imaging requests in patients with axSpA. The first three cover clinical features, patients’ symptoms and risk factors. Recommendations 4 involves previous imaging and reports, 5 contraindications to imaging or contrast media. Number 6 is about the suspected diagnosis, the reason for the exam, and clinical differential diagnoses. Eleven recommendations refer to the radiology report. The first point addresses clinical information included in the report. Recommendations 2 to 4 instruct on information about the technical conduct of the exam, the use of contrast media and image quality. Necessary imaging findings to be included in the report are listed in recommendations 5 to 7. Finally, recommendations 8 to 11 combine advice for the conclusion, for suggesting additional imaging or referral to a rheumatology expert if a different physician requested the imaging.


Table 1. Recommendations for requesting imaging in axSpA.

Imaging request



n ≥8


The referring physician should communicate important clinical information when requesting imaging exams. This clinical information should include the patient’s age, sex and HLA-B27 status.

9.2 ± 1.2



Requests for imaging should include current or past history of back pain, its duration, localization, and inflammatory features, whether present or not. For follow-up exams, a change in clinical symptoms should be indicated.

8.8 ± 1.7



Radiologists should be informed if the patient undertakes physically demanding activities or has history of childbirth (number of children and date of most recent childbirth).

9.0 ± 1.3



Radiologists should have access to previous exam images for comparison or to the respective reports if those are not available.

9.8 ± 0.9



The referral should include possible contraindications to certain types of imaging or contrast medium.

8.7 ± 2.6



The referring physician should indicate the suspected clinical diagnosis and possible alternative explanations for the symptoms, whether SpA was previously diagnosed, and if the exam is requested for primary diagnosis, to assess disease activity or treatment response.

9.3 ± 1.4



Table 2. Recommendations for reporting imaging in axSpA.

Imaging report




Clinical data


n ≥8


The report should start by summarising essential clinical information, including the patient’s age, sex, a summary of symptoms, the suspected diagnosis, whether the exam was requested for primary diagnosis or follow-up, and what imaging was available for comparison.

8.4 ± 1.8


Technical data




Radiography: The report should include the number of images, types of projections, and the patient’s positioning.

8.1 ± 2.5



MRI: The report should include the applied field strength and sequences with slice orientation and thickness, if fat suppression was applied, and whether and what type of contrast medium was administered.

8.7 ± 1.6



CT: The report should include the patient’s position, reconstructions’ orientation and slice thickness, and a general indicator for the radiation dose (e.g., dose length product).

7.7 ± 2.7



The anatomical coverage of the exam should be indicated.

8.8 ± 2.1



The report should include a general statement about image quality and complications from imaging, particularly if the exam or its interpretation is affected.

9.4 ± 1.0






SIJ: Bone marrow oedema/osteitis, erosions and fat lesions are significant findings that the report should list semi-quantitatively with their localization specified. Their absence should be stated clearly.

9.2 ± 1.1



SIJ: The report should include if other active or structural lesions are present. Structural lesions should be reported per individual bone. The radiologists can summarize the absence of those active or structural lesions in the report.

9.3 ± 1.8



Spine: The report should semi-quantitatively list bone marrow oedema/osteitis at vertebral corners. All other active and structural lesions should be mentioned if present.

9.2 ± 1.4



Spine: The location of the findings mentioned above is essential for clinical correlation, and it should be stated at the level of the individual vertebra or discovertebral unit.

9.2 ± 1.8



Findings unrelated to SpA but of potential clinical importance should be mentioned when present. These include for example gas inside the joint (“vacuum phenomenon”), osteophytes, transitional vertebrae, anatomical variations, and spinal malposition.

9.8 ± 0.6






The radiologist should state clearly if findings are compatible with SpA, based on the images and clinical information available. The conclusion should provide whether there is active inflammation or structural changes with the most prominent lesions, and give an indication of the confidence in interpretation of the findings.

9.4 ± 1.1



Based on the exam findings, differential diagnoses and their probability should be mentioned, especially if more likely than SpA.

9.8 ± 0.6



If the exam findings are inconclusive, radiologists should suggest further imaging according to their expertise.

9.4 ± 0.9



If the exam is indicative of SpA and a rheumatologist did not request the imaging investigation, the report should recommend referral to a rheumatologist for further assessment.

9.2 + 1.9



Conclusions: The ASAS recommendations provide guidance for requesting and reporting imaging in axSpA and for standardizing communication between rheumatologists and radiologists to improve diagnosis and patient care.


Timelines of the project: 2020-ongoing


Project Team

PI: Torsten Diekhoff, Xenofon Baraliakos and Denis Poddubnyy

Working group:

Torsten Diekhoff

Xenofon Baraliakos

Denis Poddubnyy

Iris Eshed

Chiara Giraudo

Hildrun Haibel

Kay-Geert Hermann

Lennart Jans

Anne Grethe Jurik

Robert Lambert

Pedo Machado

Michael Mallinson

Walter Maksymowych

Helena Marzo-Ortega

Manouk de Hooge

Victoria Navarro

Mikkel Ostergaard

Susanne J Peddersen

Monique Reijnierse

Martin Rudwaleit

Fernando Sommerfleck

Ulrich Weber