Improvements in the clinical utility of calculated T2 images of the XXXX brain.

@entity13718 @entity1 @entity9468
Magnetic Resonance Imaging (MRI) affords a considerable improvement in image contrast over other methods by virtue of the intrinsic NMR parameters spin density, T1, and T2. However, the clinical utility of routine quantification of these parameters is currently unknown. Calculated T2 images might afford additional disease specific information provided the calculation algorithm generates accurate T2 values. In this study, calculated T2 images of a @entity13718 phantom (spanning a T2 range of interest of 45.7 ms to 346.6 ms at 6 MHz) were generated utilizing a variety of calculation algorithms based upon a data set of 32 sequential @entity9468 ( @entity9468 ) images. In general, when utilizing only the earliest sequential @entity9468 after the 90 degree pulse for the T2 calculation, the greater the number of @entity9468 used in the calculation algorithm, regardless of how they were averaged, the more accurate and less noisy was the calculated image. When only limited numbers of @entity9468 were used in the calculation algorithm, accuracy and noise varied with the choice of TE suggesting that there may be optimal timings for TE for a particular T2 range of interest. Forty-two calculated T2 head images of normal subjects, based upon data sets of 16 sequential @entity9468 , were evaluated for the T2 values of normal brain. These were compared to T2 images calculated via 7 different algorithms based upon 16 @entity9468 data sets from two @entity1 with CNS pathology. An optimal algorithm was identified in which 16 @entity9468 Carr-Purcell-Meiboom-Gill (CPMG) were averaged into two images for the T2 calculation. With this algorithm, calculated images could be generated efficiently which were accurate and relatively noise free. The availability of such images maximized whatever disease specificity, and thus clinical utility, T2 information affords.
