The aim of this study is to develop an automated method to objectively compare motion artifacts in two four-dimensional computed tomography (4D CT) image sets, and identify the one that would appear to human observers with fewer or smaller artifacts. Our proposed method is based on the difference of the normalized correlation coefficients between edge slices at couch transitions, which we hypothesize may be a suitable metric to identify motion artifacts. We evaluated our method using ten pairs of 4D CT image sets that showed subtle differences in artifacts between images in a pair, which were identifiable by human observers.
View Article and Find Full Text PDFPurpose: To determine the immediate effect on corneal thickness of cataract extraction using phacoemulsification.
Design: Prospective consecutive nonrandomized humans undergoing standard small-incision phacoemulsification and intraocular lens insertion.
Methods: Corneal thickness was measured immediately preoperative and postoperatively in 58 consecutive patients undergoing phacoemulsification in the absence of other ocular abnormalities.
Objective: To compare photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in treating spherical hyperopia using the VISX STAR S2 excimer laser.
Intervention: Fifteen consecutive eyes of 15 patients underwent PRK, and 16 consecutive eyes of 16 patients underwent LASIK (follow-up: 12 months).
Main Outcome Measures: Postoperative pain, uncorrected visual acuity (UCVA), deviation from intended correction, and loss of best spectacle-corrected visual acuity (BSCVA).