RESEARCH : CTF

Performance Optimization by Patient Dose Analysis and Image Quality Assessment in Next Generation Digital Fluoroscopy


Introduction

X-ray fluoroscopy imaging systems have been widely used for many surgical operations in operating rooms and emergency rooms since their introduction in the 1980s. The real-time imaging capability of X-ray fluoroscopy imaging systems provides considerable temporal anatomical information. Thus, surgeons can improve the accuracy of their use of instrumentation, and the performance of implant placement, fracture reduction, etc. In this study, we investigated radiation doses to susceptible organs that can be scattered to the operators by simulating an orthopedic surgery using C-arm and O-arm systems in their 2-D fluoroscopy modes. We also compared the effects of shielding on the surface of the thyroid, and on direct exposure to the surgeon's hands.

Materials and Methods

Fig. 1. The experimental set-up for radiation dose measurement. (a) The C-arm system at SNUBH. (b) The O-arm system in Wooridul Hospital, Seoul, Korea.

1. C-arm fluoroscopy system

A Philips C-arm system (CE 0344, BV Pulsera, Eindhoven, the Netherlands) installed in an operating room of the orthopaedic department at Seoul National University Bundang Hospital (SNUBH) in Korea was used as shown in Fig. 1(a).

2. O-arm system for 2-D fluoroscopy imaging

A Medtronics O-arm 1000 imaging system which installed at Wooridul Hospital, Seoul, Korea was used. The system can be configured in either a 2-D fluoroscopic mode or CT mode; the fluoroscopy mode was used in this study as shown in Fig. 1(b).

Results

1. Measurement of scatter radiations

Figure 2 shows the measured dose of scattered radiation from the C-arm and O-arm systems in the 2-D fluoroscopy mode at different circular locations. The O-arm system produced more scatter radiation exposure at all locations compared with the C-arm system. Part of the reason for the difference is that the O-arm 'Thorax' option produced more than double the X-ray source than the C-arm 'Chest' option. Furthermore, the beam area of the X-ray source was wider in the O-arm; thus, it could cause more scatter from the phantoms and neighboring objects.

Figure 2. Comparison of scatter radiations between (a) O-arm and (b) C-arm fluoroscopy modes. The dose unit is microgray per minute.

2. Measurement of the operator dose

Figure 3. Comparison of radiation doses from the O-arm and C-arm systems.

Conclusion

The radiation dosage delivered to a whole body phantom representing an operator during orthopaedic surgery was investigated. Radiation doses from a recently announced O-arm CT fluoroscopy system were compared with doses from a conventional C-arm system to determine radiation exposure to the surgeons during an operation.

Participating Researchers