Differences in Volume Rendering Imaging Based on Different Algorithms in Assisting Detection of Linear Fracture of Nasal Bone Area

Objective: To explore the optimal reconstruction algorithm for volume rendering imaging (VR), improving the diagnostic efficacy of linear fractures of nasal bone area. Methods: Adult CT images of the nasal bone from August 2022 to August 2023 were retrospectively included, and 100 patients with linear fracture and 35 patients without fracture in the nasal region were randomly selected and underwent post-processing of VR with Smooth, Standard, Sharp, and Bone algorithms, respectively. Two radiologists scored the VR with and without fracture, the display of the nasal foramen, and the image quality in a double-blind method. The CT phantom was used for measuring the noise power spectrum (NPS), task transfer function (TTF) and detectability index $(d')$ of the CT images of different reconstruction algorithms using the same scanning protocol. Results: The diagnostic efficacy for linear nasal fractures varied between VR_Standard, VR_Sharp, and VR_Bone, with higher scores for the display of the nasal foramen in VR_Sharp than in VR_Standard and higher image quality scores in VR_Sharp than in VR_Standard and VR_Bone. As the sharpness of the reconstruction algorithm increased, the amount of noise and spatial resolution gradually increased. The NPS_peak and TTF_50% for the Standard, Sharp, and Bone groups were (225.85 HU²·mm², 0.42), (416.67 HU²·mm², 0.53), and (1888.20 HU²·mm², 0.8), respectively. The Sharp group had the highest $d'$ value when the diameter of the target to be measured was 1 mm. Conclusion: VR_Sharp has the best diagnostic efficacy for linear fractures in the nasal region, which better utilizes the value of VR in aiding diagnosis.