Dental imaging in clinical photon-counting CT at a quarter of DVT dose
Stefan Sawall, Joscha Maier, Sinan Şen, Holger Gehrig, Ti‐Sun Kim, Heinz‐Peter Schlemmer, Stefan O. Schönberg, Marc Kachelrieß, Maurice Rütters
Abstract
OBJECTIVE: To investigate the image quality of a low-dose dental imaging protocol in the first clinical photon-counting computed tomography (PCCT) system in comparison to a normal-dose acquisition in a digital volume tomography (DVT) system. MATERIALS AND METHODS: . DVT used 85 kV at 4 mGy. Image reconstruction was performed using the standard algorithms of each system to a voxel size of 160 × 160 × 200 µm. The dose-normalized contrast-to-noise ratio (CNRD) was measured between dentine and enamel and dentine and bone. Two readers evaluated overall diagnostic quality of images and quality of relevant structures such as root channels and dentine. RESULTS: CNRD is higher in all PCCT acquisitions. CNRD is 37 % higher for the contrast dentine-enamel and 31 % higher for the dentine-bone contrast (p < 0.05). Overall diagnostic image quality was higher for PCCT over DVT (p < 0.02 and p < 0.04 for readers 1 and 2). Quality scores for anatomical structures were higher in PCCT compared to DVT (all p < 0.05). Inter- and intrareader reproducibility were acceptable (all ICC>0.64). CONCLUSIONS: PCCT provides an increased image quality over DVT even at a lower dose level and might enable complex dental imaging protocols in the future. CLINICAL SIGNIFICANCE: The evolution of photon-counting technology and it's optimization will increasingly move dental imaging towards standardized 3D visualizations providing both minimal radiation exposure and high diagnostic accuracy.