Feasibility of second‐generation ultrasound contrast media in the detection of active sacroiliitis

Abstract

Objective. To determine whether a recently available contrast-enhanced ultrasound (CEUS) technique using secondgeneration microbubbles allows for the detection of active sacroiliitis, and to measure CEUS enhancement depth at the dorsocaudal part of the sacroiliac (SI) joints in healthy volunteers compared with patients with sacroiliitis. Methods. Forty-two consecutive patients (84 SI joints) presenting with a clinical diagnosis of sacroiliitis in 50 SI joints and 21 controls (42 SI joints) were investigated by CEUS using a standardized low mechanical index ultrasound protocol. Detected vascularity was used to retrospectively measure the enhancement depth in the dorsocaudal part of the SI joints. Results. CEUS detected enhancement in all clinically active SI joints, showing an enhancement depth into the dorsal SI joint cleft of 18.5 mm (range 16 -22.1), which was significantly higher compared with both inactive joints of patients (3.6 mm, range 0 -12; P < 0.001) and healthy controls (3.1 mm, range 0 -7.8; P < 0.001). All inactive joints were correctly classified based on a lack of deep enhancement in patients with sacroiliitis and controls (42 of 42, 100% sensitivity, 100% specificity; Cohen's ‫؍‬ 1). Conclusion. CEUS allowed the differentiation of active sacroiliitis from inactive SI joints, and proved to be a feasible method for the detection of vascularity in clinically active sacroiliitis by showing deep contrast enhancement into the SI joints not detectable in inactive joints of patients or controls. If this technique might add information to the earlier detection of sacroiliitis, it should be addressed in further studies.

Ultrasound in sacroiliitis: the picture is shaping up

“…This is supported by the inclusion of their findings in the last EULAR recommendations for the contrast agent with respect to healthy subjects [19]. However, the barrier of the costs is still palpable.…”

Local approaches to sacro-iliac joint pathologies: several unanswered questions

“…Another study from Klauser et al 17 reported data on the relevance of ultrasonography in the diagnosis of sacroiliac inflammatory involvement, adding evidence to the relevance of ultrasound also in diagnostic processes. A study from our group 15 reported another technical contribution for intra-articular ultrasound-guided injection of SIJ, proposing an alternative technical approach for inflammatory SIJ intra-articular therapy.…”

Diagnostic value of musculoskeletal ultrasound in patients with low back pain – a review of the literature

“…In a later study, the same group used second-generation microbubbles contrast agents for the detection of active sacroiliitis. They measured the depth of the contrast US enhancement in the dorsocaudal part of the SIJ in 42 patients and 21 controls [25]. CEUS showed enhancement depth into the joint cleft of 18.5 mm (range 16-22.1 mm) in all clinically active SIJs, significantly deeper compared to both inactive joints of patients (3.6 mm, range 0-12 mm), and the healthy controls (3.1 mm, range 0-7.8 mm).…”

“…However, this modality could encounter difficulties when the joints are too narrow or with many osteophytes, as well as in patients with increased Body Mass Index (BMI). In addition, the application of the contrast itself has a list of contraindications [25].…”

“…Although universally they showed an increased vascularization in sacroiliitis, one had to bear in mind the fact that vessels here were also commonly found in healthy subjects. For example, Pakkafahli et al reported vascularization near the dorsal part of the sacroiliac joint, caused by branches of the sacral arteries, in 13 out of 23 healthy controls [27] and Klauser at al found vascularization in 12 out of 21 healthy controls [25]. Furthermore, in a Doppler US study, McGrath et al used vascular signature of the dorsal sacral arteries to identify dorsal sacral nerve rami beneath the posterior long sacroiliac ligament in healthy individuals [28].…”