MRI was performed at day 7, 14, 21 and 28 post-infection. Uninfected mice were also examined. All scans were performed as described previously . Briefly, mice were anaesthetised with 1–2% isofluorane delivered in a 70:30 NO2:O2 mixture. The tail vein was cannulated with a 26 gauge × 19 mm cannula to facilitate contrast agent administration during MRI scanning (Fig.1A). The cannula was secured using super glue and masking tape and flushed with heparin to prevent the formation of blood clots. The animal was then placed prone into a mouse cradle and restrained using ear and tooth bars to minimise head movement. Anaesthesia was maintained throughout the procedures and respiration and heart rate were observed. Body temperature was continuously monitored via a rectal thermocouple and the animal maintained normothermic by an enclosed warm-water circuit (Fig.1B).Fig. 1Preparation of mouse prior to contrast enhanced magnetic resonance imaging. A. The mouse was anaesthetised (blue arrow) and the tail vein cannulated (black arrow) to allow administration of contrast agent. Electrodes were placed on the thorax and abdomen to monitor respiration and heart rate (red arrow). B. The animal was the transferred into the MRI cradle and the head restrained with ear (*) and tooth bars to prevent movement during the scan. A rectal thermocouple was used to monitor body temperature (blue wire) which was maintained by an enclosed water circuit (yellow arrow) which surrounded the mouse. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)