Pixelwise Gradient Model for Image Fusion (PGMIF): a multi-sequence magnetic resonance imaging (MRI) fusion model for tumor contrast enhancement of nasopharyngeal carcinoma.

Based on the tumor CNR and Generalized Sobel Operator Analysis, the proposed PGMIF method demonstrated its capability of enhancing MRI tumor contrast while keeping the anatomical structures of the input images. It holds promises for NPC tumor delineation in radiotherapy.