Requirements for accurate anatomical imaging of the rat for electromagnetic modeling

Modeling electromagnetic energy distribution in laboratory test animals, such as the rat, requires accurate imaging of the animal's anatomy. Accuracy, in this sense, refers to the proper positioning and shape of the various organs of the animal as they are situated in the laboratory setting. A number of factors related to the accuracy of bioelectromagnetic studies dictate the required animal positioning. The authors performed whole body imaging of Sprague-Dawley rats in an X-ray computed tomography (CT) scanner. By necessity the rats were anesthetized during imaging and a whole body thermoplastic cast was made to support the organs in the same position as they were in an awake rat. Comparisons were made to unsupported anesthetized rats and dead rats. It is concluded that it is necessary for rats to be supported in a whole-body cast to best simulate the anatomy of the awake rat. In addition, the authors note changes in abdominal structures due to death that necessitate the analysis of the animal while it is still alive.