CT Scans Mice

March 31, 2006

The new generation of clinical cardiology CT scanners are extraordinary, producing detailed three-dimensional X-ray images of the heart that capture it in mid-beat. Now, Duke radiologists have built a CT scanner capable of imaging tiny mouse hearts 3,000 times smaller than a human heart and that beat ten times as fast.

Why bother? Because genetically altered mice--in which genes affecting the heart are knocked out or otherwise altered--can offer important insights into the origins of heart disease. Despite their apparent differences, mice and humans share many of the same genes. But until now, researchers have been unable to actually see the functional effects on the heart of their genetic tinkering.

To image the mouse hearts, the scanner achieves nearly 500 times the resolution of clinically available CT scanners, says assistant research professor of radiology Cristian Badea of the Duke Center for In Vivo Microscopy, where the scanner was developed. The researchers described the new system in the journal Molecular Imaging.

While clinical scanners rotate an X-ray tube and detector around the patient, the newly developed "Micro-CT scanner" instead rotates animals between a fixed tube and detector. The researchers also place the mice on a mechanical ventilator, so that each iteration of a scan can be synchronized with both the heart and breathing motion, thereby reducing blurring of the image.