Room: AAPM ePoster Library
Brain MRI protocols often include dual-echo spin echo, typically acquired using turbo spin echo (TSE) readout. The scan provides both proton density-weighted and T2-weighted images, which provide high contrast for identification of pathology, and allow fast high-resolution and whole-brain T2 mapping. However, the intense signal of sulcal cerebrospinal fluid (CSF) contaminates cortical T2 values. We sought to reduce errors in cortical T2 values using a dual-echo fluid-attenuated pulse sequence.
MRI scans were performed on a 3.0 Tesla Philips Ingenia system with a multi-channel head coil. Structural images were obtained with a sagittal 3D T1-weighted scan, followed by conventional multi-slice dual-echo TSE. A dual-echo fluid-suppressed inversion recovery was implemented with matching field of view and spatial resolution as the dual-echo TSE. Seven healthy control subjects were enrolled in the study under an IRB-approved protocol and after providing written informed consent. T2 maps were generated from both the dual-echo TSE and the dual-echo fluid-suppressed images using mono-exponential fitting. Grey matter masks were obtained by segmenting the 3D T1-weighted image, and gray matter histograms of T2 were generated. The full-width at half-maximum (FWHM) values of the T2 distribution were calculated and compared between two sequences.
The T2 maps calculated from the dual-echo fluid suppressed sequence showed an improved dynamic range due to the reduced leakage from CSF. The T2 histogram of the cortical grey matter showed a substantial reduction of the long-T2 tail with a FWHM of 26 ms compared to FWHM of 31 ms with dual-echo TSE.
The proposed dual-echo fluid-suppressed sequence shows promising performance in quantification of cortical T2 by reducing CSF contamination. Better quantification of T2 may provide a reliable marker for detecting pathology and monitoring treatment in many brain pathologies such as multiple sclerosis.
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