New Mobile 3D C-Arm Achieves Reduced Radiation Exposure

Objectives In the past decade, several manufacturers have introduced mobile C-arms with three-dimensional (3D) capabilities that offer intraoperative visualization quality similar to that of multidetector computed tomography (MDCT), thus improving spinal procedures by allowing implant control or computer navigation on intraoperative datasets. Howver, radiation exposure to the patient remains a primary concern when using these devices.

Recently, a new motorized mobile C-arm with improved CMOS flat-panel detector and Beam Filtration technology (Vision RFD CMOSline, Ziehm, Nurenberg, Germany) was introduced with the aim of further improving image quality while significantly reducing radiation exposure to the patient.

We aimed to compare radiation exposure between a standard MDCT scan and 3D scans using both the new C-arm and its previous generation (Vision RFD3D) in a phantom setting.

Methods We used a polymethylmethacrylate (PMMA) phantom to simulate the torso of an adult human patient in the supine position. The phantom was placed on a carbon operating table and carefully centered within the C-arm’s field of view. Using each of the C-arms, 3D scans using two different protocols (standard and large patient key [LPK]) were obtained and the radiation dose was measured at the five different locations within the phantom using a radiation dosimeter. Then, CT scans with standard protocols were obtained and the dose measured at the same five locations. The main outcome measure was the computed tomography dose index with a 100-mm standard pencil dose chamber (CTDI100). We also measured the radiation dose at each of five specific locations within the phantom.

Results and Conclusion CTDI100 with the previous-generation C-arm was 44 % higher compared to CT using the standard protocol and 26 % higher using the LPK protocol.

In contrast, the new C-arm had 38 % lower CTDI100 using the standard protocol and 40 % lower CTDI100 using the LPK protocol compared to CT.

With the standard protocol, the new C-arm achieved dose reductions of 37 to 66 % at each of the center, top, right and bottom locations compared to CT. The radiation dose at the left location was the same.

With the LPK protocol, the C-arm achieved dose reductions of 31 to77 % at each of the center, top, right and bottom locations compared to CT. The radiation dose at the left location was 6 % higher.

The new CMOSline C-arm demonstrated significantly lower radiation dose compared to both the previous-generation C-arm and standard CT scans.

This reduced radiation dose, while at the same time achieving an image quality comparable to that of a CT scan, can facilitate intraoperative visualization of complex procedures. It also allows for acquiring 3D scans for navigation or to confirm implant placement with a patient dose equivalent to that of a diagnostic CT scan. Routine use of the device could lead to higher rate of intraoperative detection of complications, which could help reduce the financial burden of postoperative imaging and of revision surgery.

Stichwörter 3d c-arm; 3d imaging; radiation; intraoperative imaging

Publication History

Article published online:
15 October 2020