Expression forms and characteristics of Carr-Purcell-Meiboom-Gill sequence magnetic resonance images

We propose two expression forms of Carr-Purcell-Meiboom-Gill (CPMG) sequence magnetic resonance images using the imaging parameters of recovery time (Tr), echo interval (Te), echo number (n) from 1 to N (number of echoes). An echo image can be expressed as a form of CPMG (Tr, Texn) and the other image synthesized by summing consecutive echo images numbered from n1 to n2 (l less than or equal to n1 less than n2 less than or equal to N) as a form of CPMG (Tr, Te x n1-n2). The CPMG (Tr, Te x n) images are weighted by T1, T2 or proton density and show the better morphological representation and contrast resolution of brain tumor lesion. The difference of signal intensities among the tissues is enhanced on the synthesized CPMG (Tr, Te x n1-n2) images with the increased signal-to-noise ratio. The calculated T2 images are also observed. These forms expound the scanning conditions and image characteristics and make easy to be compared with the spin echo images.