SU‐GG‐I‐181: Noise Characterization of a Clinical Flat‐Panel Cone‐Beam Computed Tomography (CBCT) System

Purpose: To quantitatively characterize the noise performance of a neurointerventional c‐arm based flat‐panel cone‐beam computed tomography (FP‐CBCT) system with an aim of exploring the feasibility of performing cerebral blood volume (CBV) calculations. Method and Materials: Five CBCT scans of ∼11 cm diameter water phantom positioned at the isocenter were acquired at 120kVp and reconstructed to 5123 matrix with 0.33mm voxels. Central Regions of Interest (ROIs) of 1933 matrix corresponding to ∼(63mm)3 were extracted from each scan. Spatial uniformity was determined using the standard deviation (SD) in Hounsfield Units (HU) and repeatability was measured using the root‐mean‐squared deviation (RMSD) of mean signal and using the coefficient of variation (COV) of SD metrics. 3‐D noise power spectra (NPS) were computed with and without subtraction of the average ROI volume from each ROI, which allowed determination of structural noise. Results: Mean signal and SD determined from (193)3 matrix and averaged over the 5 scans were 9.3HU (range: 8.4–10.3; RMSD=0.5) and 19.1HU (range: 19.05–19.15; COV