Comparison of MRI with radiography for detecting structural lesions of the sacroiliac joint using CT as standard of reference: results from the SIMACT study

Abstract

T1w MRI was superior to radiography in the detection of structural lesion of the SI joints in patients with axSpA. Future studies should focus on finding an agreement on the definition of MRI-T1 positivity.

Low-dose CT detects more progression of bone formation in comparison to conventional radiography in patients with ankylosing spondylitis: results from the SIAS cohort

“…With further technical advances, it may be expected that additional reduction in dosing will become possible. The mean radiation dose in a study by Diekhoff et al 16 on ldCT of the sacroiliac joints was 0.51 (SD 0.18) mSv. In general, the use of ldCT is in line with the guidelines from the European Commission 17 18.…”

Improved detection of erosions in the sacroiliac joints on MRI with volumetric interpolated breath-hold examination (VIBE): results from the SIMACT study

“…All patients, but for ethical reasons (radiation) not the healthy controls, underwent a ldCT scan of the SIJs on a 64-row dual-source scanner (Somatom Definition Flash, Siemens, Erlangen, Germany) as described in detail elsewhere 7. Directly thereafter, the patients underwent a 3-Tesla pelvic MRI (Magnetom Skyra, Siemens, Erlangen, Germany).…”

“…Each SIJ was divided into 12 regions (4 quadrants in ventral, middle and dorsal position), resulting in 24 regions per patient 7. The anterior position is defined as ventral to the slices depicting the sacral neuroforamina (<180% circumference of S2).…”

“…Accurate oblique-coronal slice orientation is crucial. For each region, erosions were scored on a four-point scale as described earlier in detail7: 0 —no erosions; 1 —small isolated erosions (1–2) or questionable single erosion; 2 —definite erosions (3-5; <3 mm) or larger single erosion (>3 mm); 3 —multiple (>5) or confluent erosions. Therefore, the sum-score ranged from 0 to 72.…”

“…Moreover, it has been argued that bone marrow oedema might be too non-specific for a reliable diagnosis of axSpA in some cases—a limitation that might be overcome by adding structural lesions to the definition of a positive MRI 3–5. Furthermore, recent studies show that a T1-weighted MRI sequence is at least equally able to depict structural changes compared with radiography6 or even superior 7. State-of-the-art MRI techniques that provide a high contrast of joint space and bone and thinner slices may further improve sensitivity for those changes and, therefore, the diagnostic accuracy of MRI.…”