Recognition of sacroiliac joint structural lesions: Comparison of volumetric interpolated breath-hold examination (VIBE) sequences with different slice thicknesses to T1-weighted turbo-echo.

Purpose: To compare volumetric interpolated breath-hold examination (VIBE) with different slice thicknesses to T1-weighted turbo-echo (T1 TSE) for identification of sacroiliac joint structural lesions in patients suspected of spondyloarthritis (SpA) using CT as the gold standard.

Methods: 192 sacroiliac joints (including VIBE with both 1.2 mm and 3 mm slice thickness, T1 TSE) from 96 patients suspected of SpA were included. Joint space changes and sclerosis were evaluated for each joint. Erosions were assessed both at the level of the individual sacral and iliac bones and at the level of the entire joint for calculation of sensitivity, specificity, and accuracy. MRI and CT correlation was performed and inter-reader reliability was determined. Fat infiltration on MRI was scored.

Results: VIBE with a 1.2 mm slice thickness was the most sensitive and accurate for erosion detection at the bone level followed by 3 mm thickness VIBE and then T1 TSE (p < 0.05). At the whole-joint level, only the 1.2 mm slice thickness VIBE was superior to T1 TSE in sensitivity and accuracy (p > 0.05). For joint space changes, both VIBE sequences were superior to T1 TSE in sensitivity and accuracy (p < 0.05) and had more consistency with CT. T1 TSE was slightly more sensitive for detection of sclerosis (p < 0.05). The MR sequences did not differ in detection of fat infiltration.

Conclusion: A VIBE sequence with 1.2 mm slice thickness and less than one-minute acquisition time was superior to T1 TSE for detection of sacroiliac joint space changes and erosions in patients with suspected SpA, while the utility of the 3 mm slice thickness VIBE remains questionable.