Normal values of quantitative T2' in a spontaneously hypertensive stroke prone rat stem at 3T

Abstract

Introduction: Regarding therapy and prognosis of acute ischemic stroke the identification of ischemic penumbra is pivotal. A promising candidate is BOLD-imaging using qT2'-maps. For valid interpretation of experimental studies in animals normal values for qT2' are needed. Normal values in humans at 1.5T already exist. Normal values for cortical and subcortical structures in a spontaneously hypertensive stroke prone rat stem (SHR-SP) at a fieldstrength of 3T are reported.

Materials and methods: 39 (20 males and 19 females) spontaneously hypertensive stroke prone (SHRSP) rats were examined in a 3T scanner using a dedicated small animal coil. Mean weight was 144.1 ± 8.2g and mean age was 60.2 ± 2.7 days. For the calculation of qT2' multiple echo T2w and T2 w images were acquired. ROIs were placed into deep and cortical grey matter in five different brain regions to obtain values for qT2', qT2 and qT2.

Results: Mean qT2' for cortical grey matter was 74.76 ± 33.27 ms and 67.73 ± 17.86 ms for deep grey matter. The 99% confidence interval for cortical grey matter was 69.91-79.61 ms. For qT2 it was 79.02 ± 2.9 ms and 70.45 ± 1.89 ms, respectively. For qT2 it was 34.65 ± 5.25 ms and 31.9 ± 2.9 ms.

Conclusion: The values for qT2' presented here can serve as reference values for further studies examining the ischemic penumbra in a rat model.