MEASUREMENT OF SPIN-LATTICE RELAXATION-TIMES WITH FLASH FOR DYNAMIC MRI OF THE BREAST

Using a variable flip angle gradient refocused imaging technique. dyna mic quantitative T-1 relaxation maps acquired before and after the adm inistration of a gadolinium contrast bolus enable the concentration-ti me curve of the paramagnetic agent in breast tissue to be calculated. This imaging technique has the aim of improving the diagnostic accurac y of MR mammography. Measurements with phantoms of calibrated T-1 valu es have been carried out to investigate the accuracy of the method, wi th particular reference to errors caused by incomplete spoiling of res idual transverse magnetization and inaccurate radio frequency (RF) fli p-angle settings. A clinical example is presented. The method has pote ntial use for any patient study which necessitates rapid quantitation of changing in vivo T-1 values as a result of contrast agent injection .