IQon Spectral CT in the Diagnosis of Bowel Ischemia

A young female presented to the emergency department after a motor vehicle accident. A CT scan performed at another institution revealed a large quantity of free fluid in the abdomen; however, the doctors couldn’t explain why. A repeat CT exam using the IQon Spectral CT scanner (Philips, The Netherlands) was performed at our institution. Conventional CT images showed a similarly large quantity of free fluid; however, the spleen and liver both appeared intact.

Coronal plane spectral CT reconstructions generated a color iodine map, which were superimposed over the images with multiple energy levels to reduce noise. An increased slice thickness of about 4mm on the coronal image showed a ”seat belt” sign with avulsion of the right flank muscles from the right iliac crest. Magnification of the bowel on the iodine overlay images clearly confirmed that finding. Imaging of the cecum and terminal ileum revealed good iodine uptake in the terminal ileum. Tracking the terminal ileum downward led to an abrupt cutoff in iodine uptake, about 20cm upstream from the ileocecal valve.

The iodine map also clearly showed no iodine uptake in the loops in the right abdomen. The differences among the vascularized loops, the terminal ileum, and the nonvascularized loops can be hard to discern on conventional CT, but they cannot be missed on an iodine map.

Spectral CT enabled us to diagnose bowel ischemia with a very high degree of confidence and provide precise guidance to the surgeons, who would find 20cm of devascularized bowel about 20cm upstream from the ileocecal valve.