One visualization simulation operation system for distal femoral fracture

Ultra-low-dose CT lung screening with artificial intelligence iterative reconstruction: evaluation via automatic nodule-detection software

AIM

To test the feasibility of ultra-low-dose (ULD) computed tomography (CT) combined with an artificial intelligence iterative reconstruction (AIIR) algorithm for screening pulmonary nodules using computer-assisted diagnosis (CAD).

MATERIALS AND METHODS

A chest phantom with artificial pulmonary nodules was first scanned using the routine protocol and the ULD protocol (3.28 versus 0.18 mSv) to compare the image quality and to test the acceptability of the ULD CT protocol. Next, 147 lung-screening patients were enrolled prospectively, undergoing an additional ULD CT immediately after their routine CT examination for clinical validation. Images were reconstructed with filtered back-projection (FBP), hybrid iterative reconstruction (HIR), the AIIR, and were imported to the CAD software for preliminary nodule detection. Subjective image quality on the phantom was scored using a five-point scale and compared using the Mann-Whitney U-test. Nodule detection using CAD was evaluated for ULD HIR and AIIR images using the routine dose image as reference.

RESULTS

Higher image quality was scored for AIIR than for FBP and HIR at ULD (p<0.001). As reported by CAD, 107 patients were presented with more than five nodules on routine dose images and were chosen to represent the challenging cases at an early stage of pulmonary disease. Among such, the performance of nodule detection by CAD on ULD HIR and AIIR images was 75.2% and 92.2% of the routine dose image, respectively.

CONCLUSION

Combined with AIIR, it was feasible to use an ULD CT protocol with 95% dose reduction for CAD-based screening of pulmonary nodules.

Computer-assisted preoperative planning of bone fracture fixation surgery: A state-of-the-art review

Background: Bone fracture fixation surgery is one of the most commonly performed surgical procedures in the orthopedic field. However, fracture healing complications occur frequently, and the choice of the most optimal surgical approach often remains challenging. In the last years, computational tools have been developed with the aim to assist preoperative planning procedures of bone fracture fixation surgery. Objectives: The aims of this review are 1) to provide a comprehensive overview of the state-of-the-art in computer-assisted preoperative planning of bone fracture fixation surgery, 2) to assess the clinical feasibility of the existing virtual planning approaches, and 3) to assess their clinical efficacy in terms of clinical outcomes as compared to conventional planning methods. Methods: A literature search was performed in the MEDLINE-PubMed, Ovid-EMBASE, Ovid-EMCARE, Web of Science, and Cochrane libraries to identify articles reporting on the clinical use of computer-assisted preoperative planning of bone fracture fixation. Results: 79 articles were included to provide an overview of the state-of-the art in virtual planning. While patient-specific geometrical model construction, virtual bone fracture reduction, and virtual fixation planning are routinely applied in virtual planning, biomechanical analysis is rarely included in the planning framework. 21 of the included studies were used to assess the feasibility and efficacy of computer-assisted planning methods. The reported total mean planning duration ranged from 22 to 258 min in different studies. Computer-assisted planning resulted in reduced operation time (Standardized Mean Difference (SMD): -2.19; 95% Confidence Interval (CI): -2.87, -1.50), less blood loss (SMD: -1.99; 95% CI: -2.75, -1.24), decreased frequency of fluoroscopy (SMD: -2.18; 95% CI: -2.74, -1.61), shortened fracture healing times (SMD: -0.51; 95% CI: -0.97, -0.05) and less postoperative complications (Risk Ratio (RR): 0.64, 95% CI: 0.46, 0.90). No significant differences were found in hospitalization duration. Some studies reported improvements in reduction quality and functional outcomes but these results were not pooled for meta-analysis, since the reported outcome measures were too heterogeneous. Conclusion: Current computer-assisted planning approaches are feasible to be used in clinical practice and have been shown to improve clinical outcomes. Including biomechanical analysis into the framework has the potential to further improve clinical outcome.

Application of Finite Element Analysis Combined With Virtual Computer in Preoperative Planning of Distal Femoral Fracture

Background

Distal femoral fractures are increasing with an aging population. The computer-assisted preoperative planning has great potential, but there are no preoperative plans to determine appropriate fixation methods for distal femoral fractures on an individual basis. The aims of this study are: (1) to describe the technique of finite element analysis combined with computer-assisted preoperative planning to determine a fixation method for distal femoral fractures and (2) to evaluate the intra-operative realization of this technology and the clinical outcomes based on it for distal femoral fractures.

Materials and Methods

Between January 2017 and January 2020, 31 patients with distal femoral fractures treated by open reduction and internal fixation were included and randomly divided into two groups based on preoperative planning methods: conventional group (n = 15) and computer-assisted group (n = 16). Firstly, how to determine the most appropriate plate and screw length and placement in the preoperative planning of distal femoral fractures was described. The time taken for preoperative planning for different fracture types in the computer-assisted group was then analyzed. Finally, intraoperative and postoperative parameters were compared between the conventional and computer-assisted groups, assessing operative time, intraoperative blood loss, number of intraoperative fluoroscopies, days of hospital stay, Visual Analog Scale for Pain Score (VAS), and Knee Society Score (KSS).

Results

Mean total planning time for 33-A, 33-B, and 33-C fractures in computer-assisted group were 194.8 ± 6.49, 163.71 ± 9.22, and 237 ± 5.33 min, respectively. Compared with the conventional group, the patients in the computer-assisted group had less blood loss, fewer fluoroscopic images, and shorter operation time (p < 0.05). However, there was no significant difference in the hospitalization days, KSS score and VAS score between the two groups (p > 0.05).

Conclusions

The results of this study show that finite element combined with computer-assisted preoperative planning can effectively help surgeons to make accurate and clinically relevant preoperative planning for distal femoral fractures, especially in the selection of appropriate plate length and screw positioning.