Integrative Ecophysiology, Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
Department of Biology and Chemistry, University of Bremen, Bibliothekstraße 1, 28359, Bremen, Germany.
MAGMA. 2019 Oct;32(5):567-579. doi: 10.1007/s10334-019-00752-4. Epub 2019 May 23.
An approach is presented for high-field MRI studies of the cardiovascular system (CVS) of a marine crustacean, the edible crab Cancer pagurus, submerged in highly conductive seawater.
Structure and function of the CVS were investigated at 9.4 T. Cardiac motion was studied using self-gated CINE MRI. Imaging protocols and radio-frequency coil arrangements were tested for anatomical imaging. Haemolymph flow was quantified using phase-contrast angiography. Signal-to-noise-ratios and flow velocities in afferent and efferent branchial veins were compared with Student's t test (n = 5).
Seawater induced signal losses were dependent on imaging protocols and RF coil setup. Internal cardiac structures could be visualized with high spatial resolution within 8 min using a gradient-echo technique. Variations in haemolymph flow in different vessels could be determined over time. Maximum flow was similar within individual vessels and corresponded to literature values from Doppler measurements. Heart contractions were more pronounced in lateral and dorso-ventral directions than in the anterior-posterior direction.
Choosing adequate imaging protocols in combination with a specific RF coil arrangement allows to monitor various parts of the crustacean CVS with exceptionally high spatial resolution despite the adverse effects of seawater at 9.4 T.
提出了一种方法，用于在高磁场（9.4T）下研究海洋甲壳动物——食用蟹（Cancer pagurus）心血管系统（CVS），该方法可将甲壳动物浸没在高导电性海水中。
在 9.4T 下研究 CVS 的结构和功能。使用自门控 CINE MRI 研究心脏运动。测试了成像协议和射频线圈排列，以进行解剖成像。使用相位对比血管造影术定量血液流动。使用学生 t 检验（n=5）比较了流入和流出鳃静脉的信号噪声比和流速。
海水诱导的信号损失取决于成像协议和 RF 线圈设置。使用梯度回波技术，可在 8 分钟内以高空间分辨率可视化内部心脏结构。可以随时间确定不同血管中的血液流动变化。个体血管中的最大流量相似，与多普勒测量的文献值相对应。心脏收缩在侧向和背腹方向比在前-后方向更明显。
选择合适的成像协议并结合特定的 RF 线圈排列，即使在 9.4T 下海水的不利影响下，也允许以极高的空间分辨率监测甲壳动物 CVS 的各个部位。
