BREAST-CANCER - GADOLINIUM-ENHANCED MR-IMAGING WITH A 0.5-T OPEN IMAGER AND 3-POINT DIXON TECHNIQUE

PURPOSE: To investigate the three-point Dixon technique as a method fo r obtaining fat-nulled images of contrast material-enhancing breast le sions with a 0.5-T open magnetic resonance (MR) imager. MATERIALS AND METHODS: Real and imaginary source images were obtained with an interl eaved gradient-echo sequence with a repetition time of 550 msec and ec ho times of 12.8, 19.8, and 26.8 msec. Twenty-four to 28 sections were obtained in the sagittal plane with a 90 degrees flip angle, 256 x 19 2 matrix, 3-4.5-mm section thickness, and acquisition time of 10 minut es 54 seconds. A three-point Dixon reconstruction algorithm was used t o generate water-specific, fat-specific, and combined images from the raw image data. Twelve breasts in 10 patients and one healthy voluntee r were imaged. RESULTS: Three-point Dixon images were superior to exte nded tow-point Dixon and fat-suppressed images and to images generated by means of subtraction of three-dimensional fast spoiled gradient-ec ho images obtained before contrast material injection from those obtai ned after. CONCLUSION: Three-point Dixon imaging provides a robust met hod for creating fat-nulled images of enhancing breast lesions in the 0.5-T open MR environment. Water-specific three-point Dixon images are successful in regions of B-0 heterogeneity and are superior to fat-su ppressed images. They are much less susceptible to motion artifact tha n are substraction images.