TY - JOUR
T1 - T 2 relaxometry measurements in low spatial frequency brain regions differ between fast spin-echo and multiple-echo spin-echo sequences
AU - Rajagopalan, Venkateswaran
AU - Lowe, Mark J.
AU - Beall, Erik B.
AU - Yue, Guang H.
AU - Pioro, Erik P.
PY - 2013/10
Y1 - 2013/10
N2 - Object: Dual-echo fast spin-echo (FSE) sequences are used in T 2 relaxometry studies of neurological disorders because of shorter clinical scanning times and protocol simplicity. However, FSE sequences have possible spatial frequency-dependent effects, and derived T 2 values may include errors that depend on the spatial frequency characteristics of the brain region of interest. Materials and methods: Dual-echo FSE and multi-echo spin-echo (MESE) sequences were acquired in nine subjects. The T 2 decay curves for FSE and MESE sequences were estimated and percent error maps were generated. T 2 error values were obtained along each patient's corticospinal tract (CST). Whole-brain white matter (WM) and gray matter (GM) T 2 error values were also obtained. The paired t test was performed to evaluate differences in T 2 values in the CST between FSE and MESE sequences. Results: Histograms of error values in CST and in whole-brain WM and GM structures revealed systematic errors in FSE sequences. Significant differences (P < 0.001) in CST T 2 values were also observed between FSE and MESE sequences. Conclusion: Our findings indicate that T 2 values derived from FSE sequences are prone to large errors, even in low spatial frequency regions such as the CST, when compared to MESE sequences. Future studies should be aware of this limitation of FSE sequences.
AB - Object: Dual-echo fast spin-echo (FSE) sequences are used in T 2 relaxometry studies of neurological disorders because of shorter clinical scanning times and protocol simplicity. However, FSE sequences have possible spatial frequency-dependent effects, and derived T 2 values may include errors that depend on the spatial frequency characteristics of the brain region of interest. Materials and methods: Dual-echo FSE and multi-echo spin-echo (MESE) sequences were acquired in nine subjects. The T 2 decay curves for FSE and MESE sequences were estimated and percent error maps were generated. T 2 error values were obtained along each patient's corticospinal tract (CST). Whole-brain white matter (WM) and gray matter (GM) T 2 error values were also obtained. The paired t test was performed to evaluate differences in T 2 values in the CST between FSE and MESE sequences. Results: Histograms of error values in CST and in whole-brain WM and GM structures revealed systematic errors in FSE sequences. Significant differences (P < 0.001) in CST T 2 values were also observed between FSE and MESE sequences. Conclusion: Our findings indicate that T 2 values derived from FSE sequences are prone to large errors, even in low spatial frequency regions such as the CST, when compared to MESE sequences. Future studies should be aware of this limitation of FSE sequences.
KW - Dual-echo fast spin echo (FSE)
KW - Multi-echo spin echo (MESE)
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U2 - 10.1007/s10334-012-0364-1
DO - 10.1007/s10334-012-0364-1
M3 - Article
C2 - 23354513
AN - SCOPUS:84899468097
SN - 0968-5243
VL - 26
SP - 443
EP - 450
JO - Magnetic Resonance Materials in Physics, Biology, and Medicine
JF - Magnetic Resonance Materials in Physics, Biology, and Medicine
IS - 5
ER -