Volk A, Crémieux A C, Belmatoug N, Vallois J M, Pocidalo J J, Carbon C
INSERM U.350, Institut Curie-Biologie, Centre Universitaire, Orsay, France.
Magn Reson Imaging. 1994;12(7):1039-46. doi: 10.1016/0730-725x(94)91235-o.
The rabbit model of osteomyelitis introduced by C.W. Norden, based on injection of an infecting solution (Staphylococcus aureus, sodium morrhuate) into the tibia, was studied at 4.7 Tesla with a time-efficient chemical shift selective imaging technique, Chemical Shift Specific Slice Selection (C4S). The evolution of the disease over several weeks was followed on water-selective, fat-selective, and sum images obtained simultaneously with this imaging sequence. Experiments were performed either on different groups of rabbits at different times after infection with subsequent sacrifice of the animal and microbiological analysis of the infected tibia or on the same group of animals imaged several times after infection. Associated analysis of the water and fat selective images revealed marrow modifications very early (Day 5 after inoculation) demonstrating the high sensitivity of the employed imaging technique. Later on, bone modifications were best identified on the sum images. Additional experiments performed on animals injected with a noninfecting solution containing only sodium morrhuate showed however that the sclerosing agent alone can yield images similar to those produced by infection at early stages after inoculation. Therefore, the Norden model would not be suitable for monitoring quantitatively outcome of therapy by magnetic resonance imaging. It is however well adapted for the evaluation and optimization of MRI techniques or protocols intended to detect early changes of bone marrow produced by septic or aseptic infarct.
C.W. Norden提出的骨髓炎兔模型，是通过将感染溶液（金黄色葡萄球菌、鱼肝油酸钠）注入胫骨构建的，本研究采用高效化学位移选择性成像技术——化学位移特定层面选择（C4S），在4.7特斯拉磁场下进行。利用该成像序列同步获取的水选择性、脂肪选择性和总和图像，跟踪疾病在数周内的发展情况。实验分别在感染后不同时间对不同组兔子进行，随后处死动物并对感染的胫骨进行微生物分析；或者对同一组动物在感染后进行多次成像。对水选择性和脂肪选择性图像的相关分析显示，在感染后很早（接种后第5天）就出现了骨髓改变，这证明了所采用成像技术的高敏感性。后来，在总和图像上能最好地识别出骨骼改变。然而，对仅注射含鱼肝油酸钠的非感染溶液的动物进行的额外实验表明，仅硬化剂在接种后的早期阶段就能产生与感染相似的图像。因此，Norden模型不适用于通过磁共振成像定量监测治疗结果。不过，它非常适合用于评估和优化旨在检测由感染性或无菌性梗死引起的骨髓早期变化的MRI技术或方案。
