Alterations in intracranial volume following cross-clamping of the descending thoracic aorta in pigs — An experimental study using MRI

Objectives: To determine whether alterations in intracranial volume occurred following cross-clamping of the descending thoracic aorta in pigs. Design and setting: Laboratory animal study. Materials: Eight pigs undergoing cross-clamping of the descending thoracic aorta for 30 min. Chief outcome measures: A Philips Gyroscan T5-II Release 3 (0.5 T) was used to obtain intracranial images before cross-clamping, during cross-clamping and after declamping. The ventricular volume was measured on Spin Echo T1-weighted images. The signal intensity of the cerebral tissue was measured on Spin Echo T2-weighted images. Increased signal intensity of the cerebral tissue relative to an external reference was used as an indicator of cerebral oedema. Main results: The ventricular volume decreased to 89% ( P p Conclusions: In this study, ventricular volume decreased following cross-clamping of the descending thoracic aorta. Since no cerebral oedema was observed, the decrease of ventricular volume was most likely due to increased intracranial blood volume.