Audit on MRI Protocol and Reporting Descriptors for Suspected Inflammatory Sacroiliitis

Audit of MRI protocol and reporting descriptors for suspected inflammatory sacroilitis.

Sacroiliitis demonstrated by MRI is an integral part of the ASAS criteria for axial spondyloarthritis (AS) (1). The diagnosis of early sacroiliitis by MRI is based on the evaluation of active and structural postinflammaory changes according to the ASAS classification criteria (2).

MRI is known to be the most sensitive imaging modality to diagnose sacroiliitis by visualizing inflammatory lesions before any structural changes demonstrated on radiograph or CT (3). MRI is also the only imaging modality that can detect bone marrow oedema, which is the hallmark and key to the diagnosis of inflammatory sacroiliitis (4).

Optimisation of imaging and precision of reporting enables treatment with biologics and other disease modifying drugs. MRI is recommended as the first imaging examination for suspected sacroiliitis in RCR iRefer (6).

The ESSR Arthritis Subcommittee published a guideline regarding the standards of MRI protocol and reporting descriptors for inflammatory sacroilitis to be achieved (2). Contrast-enhanced MRI is no longer needed to make a diagnosis of sacroiliitis as stated by the 2015 evidence-based EULAR recommendations (5).

The standard: 

1. MRI sequences indicated for suspected inflammatory sacroiliitis should include coronal oblique T1-weighted, coronal oblique STIR/TIRM and visualization in two perpendicular planes. No contrast administration is needed.

2. MRI reports should contain a description of active (bone marrow edema, capsulitis, synovitis and enthesitis) and structural changes (subchondral sclerosis, bone erosions, periarticular fat deposition, bony bridge, ankyloses).

3. The site, number and location of any lesion found should be documented.

Target: 

100% of MRI protocol and reports for inflammatory sacroiliitis should meet these standards.

Indicators: 

The percentage of MRI protocol and reports which adhere to each of the standards.

Data items to be collected: 

1. Does the MRI protocol encompass the correct sequences and planes?

2. Is there a correct documentation of the presence or absence of inflammatory lesions and structural changes?

3. Is there a correct documentation of number, site and location of any lesion detected?

Suggested number: 

MRI scans indicated for inflammatory sacroilitis for both pediatrics and adults should be collected and reviewed. All cases performed during the preceding six months, or the most recent 50 consecutive cases (whichever number is greater).

• Ask for a protection safety survey from the local Radiation Safety Adviser in order to solve problems revealed by (repeatedly) unsatisfactory audit results

• Consider the purchase of purpose-manufactured protection kits such as the King’s Lynn Gonad Protection System [1]

• Provide each room with a kit

• Store gonad shields on purpose-built racks. Remove and destroy all other lead protection alternatives (used for gonad protection) found in the rooms, which are not appropriate or purpose-produced

- Simple inspection proforma

- No assistance required

- Radiographer (10 minutes per room)

1. White J. The King’s Lynn Gonad Shield. Radiography 1977;43:137–8.

2. Plaut S. Radiation Protection in the X Ray Department. Oxford: Butterworth-Heinemann, 1993:113–4.

3. The Ionising Radiations (Protection of Persons Undergoing Medical Examination or Treatment) Regulations 1988 (POPUMET). London: HMSO, 1988.

4. National Radiological Protection Board. Occupational, public and medical exposure: guidance on the 1990 recommendations of the ICRP. Didcot: NRPB, 1990.

Taken from Clinical Audit in Radiology 100+ recipes RCR 1996