Flow measurements with a high‐speed computed tomography scanner

A high-speed computed tomography (CT) scanner with a scan time of 50 ms was used to measure flow in a phantom constructed to simulate both tissue and vessels. After a bolus injection of iodinated contrast medium, the phantom was scanned at a rate of up to 2 images/s. A gamma-variate curve was fit to the time-density data obtained from the inlet and outlet, as well as from the tissue-equivalent part of the phantom. Flow was then calculated using different curves and curve parameters according to the Stewart-Hamilton equation, the mean transit time, and a modification of the Sapirstein principle. Actual flow rates were assessed by timed sampling. The results demonstrated that high-speed CT can measure flow accurately by all these methods. Application of high-speed CT for flow measurements in experimental animals and patients is, therefore, promising. The limitations of each technique for clinical application are discussed.