Preliminary Application of High-Definition CT Gemstone Spectral Imaging in Hand and Foot Tendons

Objective: To assess the feasibility of visualizing hand and foot tendon anatomy and disorders by Gemstone Spectral Imaging (GSI) high-definition CT (HDCT). Materials and Methods: Thirty-five patients who suffered from hand or foot pain were scanned with GSI mode HDCT and MRI. Spectrum analysis was used to select the monochromatic images that provide the optimal contrast-to-noise ratio (CNR) for tendons. The image quality at the best selected monochromatic level and the conventional polychromatic images were compared. Tendon anatomy and disease were also analyzed at GSI and MRI. Results: The monochromatic images at about 65 keV (mean 65.09 ${\pm}$ 2.98) provided the optimal CNR for hand and foot tendons. The image quality at the optimal selected monochromatic level was superior to conventional polychromatic images (p = 0.005, p < 0.05). GSI was useful in visualizing hand and foot tendon anatomy and disorders. There were no statistical differences between GSI and MRI with regard to tendon thickening (${\chi}^2$ = 0, p > 0.05), compression (${\chi}^2$ = 0.5, p > 0.05), absence (${\chi}^2$ = 0, p > 0.05) and rupture (${\chi}^2$ = 0, p > 0.05). GSI was significantly less sensitive than MRI in displaying tendon adhesion (${\chi}^2$ = 4.17, p < 0.05), degeneration (${\chi}^2$ = 4.17, p < 0.05), and tendinous sheath disease (${\chi}^2$ = 10.08, p < 0.05). Conclusion: GSI with monochromatic images at 65 keV displays clearly the most hand and foot tendon anatomy and disorders with image quality improved, as compared with conventional polychromatic images. It may be used solely or combined with MRI in clinical work, depending on individual patient disease condition.