A new NOE-mediated MT signal at around-1.6 ppm for detecting ischemic stroke in rat brain

作者：Zhang Xiao Yong; Wang Feng; Afzal Aqeela; Xu Junzhong; Gore John C; Gochberg Daniel F; Zu Zhongliang^*

来源：Magnetic Resonance Imaging, 2016, 34(8): 1100-1106.

DOI：10.1016/j.mri.2016.05.002

• Magnetization transfer (MT)
• Chemical exchange saturation transfer (CEST)
• Nuclear Overhauser enhancement (NOE)
• Ischemic stroke

In the present work, we reported a new nuclear Overhauser enhancement (NOE)-mediated magnetization transfer (MT) signal at around -1.6 ppm (NOE(-1.6)) in rat brain and investigated its application in the detection of acute ischemic stroke in rodent model. Using continuous wave (CW) MT sequence, the NOE(-1.6) is reliably detected in rat brain. The amplitude of this new NOE signal in rat brain was quantified using a 5-pool Lorentzian Z-spectral fitting method. Amplitudes of amide, amine, NOE at -3.5 ppm (NOE(-3.5)), as well as NOE(-1.6) were mapped using this fitting method in rat brain. Several other conventional imaging parameters (R-1, R-2, apparent diffusion coefficient (ADC), and semi-solid pool size ratio (PSR)) were also measured. Our results show that NOE(-1.6), R-1, R-2, ADC, and APT signals from stroke lesion have significant changes at 0.5-1 h after stroke. Compared with several other imaging parameters, NOE(-1.6) shows the strongest contrast differences between stroke and contralateral normal tissues and stays consistent over time until 2 h after onset of stroke. Our results demonstrate that this new NOE(-1.6) signal in rat brain is a new potential contrast for assessment of acute stroke in vivo and might provide broad applications in the detection of other abnormal tissues.

• 出版日期2016-10