Impact of calcium suppression imaging on hand and wrist fracture detection in spectral CT: a comparison with X-ray and CT.

Abstract

Objectives: To evaluate the impact of calcium suppression (CaSupp) imaging of spectral computed tomography (SpCT) on fracture detection in clinical routine in the acute trauma setting of the hand and wrist.

Materials and methods: Retrospective inclusion of 125 patients who underwent both X-ray and SpCT examinations of the hand and wrist in an acute trauma setting. Two independent readers evaluated fracture presence on X-ray, conventional CT, and conventional CT plus CaSupp images (time interval 4 weeks, each). Bone bruise (BBr) presence was evaluated on CaSupp images. Sensitivity and specificity were calculated according to the consensus reading as the reference standard.

Results: Of the 125 patients (mean age, 55 years ± 19.5 [SD]; 67 female), 120 presented with at least one fracture, for a total of 212 fractured bones. Sensitivity was increased significantly for both readers in CT + CaSupp (94.3 and 97.2%) compared to conventional CT (88.2 and 90.1%, p < .01) and X-ray (72.6 and 75.9%, p < .01). Specificity was 99.9 and 100% for CT + CaSupp, 99.8 and 99.9% for conventional CT, and 99.4 and 99.9% for X-ray. Reader 1 detected 13 additional fractures in CT + CaSupp compared to conventional CT alone, while Reader 2 detected 15 additional fractures. BBr was seen in 58% of all fractures, in 76% of multifragmentary fractures, and in 13% of avulsion fractures. Inter-reader κ was almost perfect for X-ray (κ = .85), CT and CT + CaSupp (κ = .95), and substantial for BBr (κ = .61).

Conclusion: CaSupp images in combination with conventional CT images significantly improved sensitivity for acute trauma fracture detection in the hand and wrist compared to conventional CT images alone and X-ray.