A Projection-based Intensity Correction Method of Phased-Array Coil Images

PURPOSE: To develop a novel approach to calculate the sensitivity profiles of the phased array coil for use in non-uniform intensity correction. MATERIALS AND METHODS: The proposed intensity correction method estimates the sensitivity profile of the coil to extract intensity variations that represent the scanned image. The sensitivity profile is estimated by fitting a non-linear curve to various angles of projections through the imaged object in order to eliminate the high-frequency image content. Filtered back projection is then used to compute the estimates of the sensitivity profile of each coil. The method was applied both to phantom and brain images from 8-channel phased-array coil and 4-channel phased-array coil, respectively. RESULTS: Intensity-corrected images from the proposed method have more uniform intensity than those from the commonly used `sum-of-squares' approach. By using the proposed correction method, the intensity variation was reduced to 6.1% from 13.1%, acquired from the `sum-of-squares'. CONCLUSION: The proposed method is more effective at correcting the intensity non-uniformity of the phased-array surface-coil images than the conventional`sum-of-squares' method.

A Projection-based Intensity Correction Method of Phased-Array Coil Images

PURPOSE: To develop a novel approach to calculate the sensitivity profiles of the phased array coil for use in non-uniform intensity correction. MATERIALS AND METHODS: The proposed intensity correction method estimates the sensitivity profile of the coil to extract intensity variations that represent the scanned image. The sensitivity profile is estimated by fitting a non-linear curve to various angles of projections through the imaged object in order to eliminate the high-frequency image content. Filtered back projection is then used to compute the estimates of the sensitivity profile of each coil. The method was applied both to phantom and brain images from 8-channel phased-array coil and 4-channel phased-array coil, respectively. RESULTS: Intensity-corrected images from the proposed method have more uniform intensity than those from the commonly used `sum-of-squares' approach. By using the proposed correction method, the intensity variation was reduced to 6.1% from 13.1%, acquired from the `sum-of-squares'. CONCLUSION: The proposed method is more effective at correcting the intensity non-uniformity of the phased-array surface-coil images than the conventional`sum-of-squares' method.