Not all Flat-Panel C-Arms are Created Equal: A Comparison of Three Major Manufacturers.

INTRODUCTION: Flat-Panel Detector C-arms (FC) are reported to reduce radiation exposure and improve image quality compared to conventional image intensifier C-arms (CC). The purpose of this study was to compare radiation exposure and image quality between three commonly used FCs.

MATERIALS AND METHODS: A cadaver model was placed in prone position to simulate percutaneous nephrolithotomy. We compared three FCs: OEC Elite CFD from GE HealthCare, Zenition 70 from Philips, and Ziehm Vision RFD from Ziehm Imaging. To measure the radiation dose, optically stimulated luminescence dosimeters (OSLDs) were utilized during five 300-second trials, conducted under three settings: automatic exposure control (AEC), AEC with low dose (LD), and LD with the lowest pulse rate (LDLP). Ten blinded urologists evaluated image quality. Data was statistically analyzed using ANOVA and Tukey's B post-hoc tests.

RESULTS: In the AEC setting, the Philips C-arm demonstrated lower ventral OSLD exposure (42,446 mrad) compared to both the GE (51,076 mrad) and Ziehm (83,178 mrad; p<0.001). Similarly, in the LD setting, the Philips C-arm resulted in less ventral OSLD exposure (25,926 mrad) than both Ziehm (30,956 mrad) and GE (38,209 mrad; p<0.001). Meanwhile, in the LDLP setting, the Ziehm C-arm showed less ventral OSLD exposure (4,019 mrad) than both GE (7,418 mrad) and Philips (8,229 mrad; p<0.001). All three manufacturers received adequate image quality ratings at the AEC and LD settings. However, at LDLP, the Ziehm C-arm received inadequate ratings in 8% of images, while both GE and Philips received 100% adequate ratings (p=0.016).

CONCLUSIONS: Radiation produced by flat-panel C-arms varies dramatically, with the highest exposure (Ziehm) being almost double the lowest (Philips) in AEC. Improved picture quality at the lowest settings may come at the cost of increased radiation dose. Surgeons should carefully select the machine and settings to minimize radiation exposure while still preserving image quality.