PURPOSE: To evaluate the magnetic susceptibility effect on spin-echo MR images of the pituitary gland. METHODS: Air-in-water phantom experiments and studies in normal volunteers were performed using various sampling bandwidth (8.3-33.3 kHz) spin-echo sequences with the polarity of the readout gradient normal or reversed. RESULTS: Attachment of a sphenoid septum to the sellar floor was the major factor in the appearance of the inferior surface of the pituitary gland. Patterns of distortion and/or artifactual signal intensities, related to the presence or absence of the attachment, were accentuated on the images with narrower bandwidth. A "spearhead shape" deformity of the sphenoid sinus was observed both in the air-in-water phantom experiment, and when no sphenoid septum was present. When a sphenoid septum was present, two spearhead shapes side by side were present. High-intensity artifacts were seen where the sellar floor was misplaced into the pituitary gland. CONCLUSION: Knowledge of the patterns of distortion and high-intensity artifact is important in the diagnosis of pituitary lesions.
PURPOSE: To evaluate the magnetic susceptibility effect on spin-echo MR images of the pituitary gland. METHODS: Air-in-water phantom experiments and studies in normal volunteers were performed using various sampling bandwidth (8.3-33.3 kHz) spin-echo sequences with the polarity of the readout gradient normal or reversed. RESULTS: Attachment of a sphenoid septum to the sellar floor was the major factor in the appearance of the inferior surface of the pituitary gland. Patterns of distortion and/or artifactual signal intensities, related to the presence or absence of the attachment, were accentuated on the images with narrower bandwidth. A "spearhead shape" deformity of the sphenoid sinus was observed both in the air-in-water phantom experiment, and when no sphenoid septum was present. When a sphenoid septum was present, two spearhead shapes side by side were present. High-intensity artifacts were seen where the sellar floor was misplaced into the pituitary gland. CONCLUSION: Knowledge of the patterns of distortion and high-intensity artifact is important in the diagnosis of pituitary lesions.
Authors: John S Ginn; Nzhde Agazaryan; Minsong Cao; Umar Baharom; Daniel A Low; Yingli Yang; Yu Gao; Peng Hu; Percy Lee; James M Lamb Journal: Phys Med Biol Date: 2017-04-20 Impact factor: 3.609