Purpose: To achieve significant dose reduction by the removal of the anti-scatter grid during cerebral angiography, using a bi-plane interventional fluoroscopy system in a tertiary pediatric hospital.
Methods: Cerebral angiography is a fluoroscopic X-ray examination that requires significant spatial resolution in order to see small blood vessels in the cerebral vasculature. Typical cerebral angiogram is performed using bi-plane interventional fluoroscopy to see the blood vessels of interest from two angles. Modern interventional fluoroscopy systems are equipped with removable anti-scatter grids that improve image quality at the expense of higher radiation to the patient. However, we hypothesized that the use of anti-scatter grid would not drastically improve the diagnostic quality of the imaging in pediatric cerebral angiography.The anti-scatter grid was removed from the lateral plane of a bi-plane interventional fluoroscope used for cerebral angiograms, which were thereafter performed by an experienced interventional neuroradiologist who had previously used to use the anti-scatter grid for the same procedures. Dose-Area-Product (DAP) and Reference Point Air Kerma (K) from both fluoroscopic and acquisition procedures along with fluoroscopic time of the lateral fluoroscopic examinations were compared for 54 cerebral angiograms performed with the anti-scatter grid in place and 48 procedures without the grid.
Results: The interventional neuroradiologist observed no noticeable changes in diagnostic image quality and in fluoroscopic time between the procedures with and without the anti-scatter grid among all 102 procedures. The median reduction of DAP was 47% and 33%, and the median reduction of K was 40% and 29% for patients younger and older than 10 years old, respectively.
Conclusion: The removal of the anti-scatter grid from the lateral plane during cerebral angiography is feasible, and results in significant reduction of radiation exposure to pediatric patients and clinical staff without sacrificing the overall diagnostic performance of this complex procedure.