Xiaowei Zhu, Presenter: Nothing to Disclose

Anne Marie Cahill MBBCh, Abstract Co-Author: Nothing to Disclose

The development of C-arm cone-beam CT (C-arm CT) has remarkably improved anatomic visualization capabilities for interventional radiology (IR) procedures. We previously reported our progress in optimizing Temporomandibular Joint (TMJ) treatments utilizing C-arm CT, based on measurements of anthropomorphic phantoms. This study is a review of the clinical outcomes of the implementation of the phantom-predicted techniques.

The IR Radiologists and Technologists were instructed to use optimized TMJ C-arm CT techniques (short rotation time, low receptor dose) which were pre programmed on to the imaging console as customized options. C-arm CT automatically determines and inserts the proper thickness of the copper filtration (Cu) based on patient attenuation during live C-armCT rotations. We retrospectively reviewed exam reports from C-arm CT rotational TMJ studies between October 2007 and March 2010. We extracted patient age and Dose-Area-Product (DAP) from each rotation and reviewed other information including the selections of the dose options and thickness of Cu.

24 rotations (Group A) were performed prior to the implementation of the optimized TMJ C-arm CT protocol, 62 were performed after (Group B). The average ages of Groups A and Group B were 14.1+4.8y (87% >10y) and 13.3+4.4y (84% >10y), and the average DAPs were 357.9 and 19.1 microGym2 respectively. The difference in average DAPs reflects a radiation dose reduction of 95% using the optimized techniques, close to the 94% predicted by our phantom study. The optimized dose is approximately half the radiation dose from that of a conventional low dose TMJ CT with the same z-direction collimations.

Using optimized C-arm CT TMJ radiation dose techniques, a radiation dose reduction of 95% was achieved compared to the non customized standard default dose settings provided by the manufacturer.

Implementation of the optimized radiation dose techniques predicted from phantom study has significantly reduced radiation doses to our patients receiving TMJ treatments utilizing C-arm CT in IR.

Zhu, X, Cahill, A, A Review of the Clinical Outcomes of Implementing Optimized Radiation Dose Techniques for Temporomandibular Joint (TMJ) Treatments Utilizing C-arm CT.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9015550.html