title: Dynamic CT perfusion measurement in a cardiac phantom.
abstract: Widespread clinical implementation of dynamic CT myocardial perfusion has been hampered by its limited accuracy and high radiation dose. The purpose of this study was to evaluate the accuracy and radiation dose reduction of a dynamic CT myocardial perfusion technique based on first pass analysis (FPA). To test the FPA technique, a pulsatile pump was used to generate known perfusion rates in a range of 0.96-2.49 mL/min/g. All the known perfusion rates were determined using an ultrasonic flow probe and the known mass of the perfusion volume. FPA and maximum slope model (MSM) perfusion rates were measured using volume scans acquired from a 320-slice CT scanner, and then compared to the known perfusion rates. The measured perfusion using FPA (P(FPA)), with two volume scans, and the maximum slope model (P(MSM)) were related to known perfusion (P(K)) by P(FPA) = 0.91P(K) + 0.06 (r = 0.98) and P(MSM) = 0.25P(K) - 0.02 (r = 0.96), respectively. The standard error of estimate for the FPA technique, using two volume scans, and the MSM was 0.14 and 0.30 mL/min/g, respectively. The estimated radiation dose required for the FPA technique with two volume scans and the MSM was 2.6 and 11.7-17.5 mSv, respectively. Therefore, the FPA technique can yield accurate perfusion measurements using as few as two volume scans, corresponding to approximately a factor of four reductions in radiation dose as compared with the currently available MSM. In conclusion, the results of the study indicate that the FPA technique can make accurate dynamic CT perfusion measurements over a range of clinically relevant perfusion rates, while substantially reducing radiation dose, as compared to currently available dynamic CT perfusion techniques.
authors.affiliation: Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, CA, 92697, USA.
authors.forename: Benjamin P
authors.initials: BP
authors.lastname: Ziemer
authors.affiliation: Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, CA, 92697, USA.
authors.forename: Logan
authors.initials: L
authors.lastname: Hubbard
authors.affiliation: Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, CA, 92697, USA.
authors.forename: Jerry
authors.initials: J
authors.lastname: Lipinski
authors.affiliation: Department of Radiological Sciences, Medical Sciences I, B-140, University of California, Irvine, CA, 92697, USA. symolloi@uci.edu.
authors.forename: Sabee
authors.initials: S
authors.lastname: Molloi
mesh_terms: D001783:Blood Flow Velocity; D003326:Coronary Circulation; D006801:Humans; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D055414:Myocardial Perfusion Imaging / Q000295:instrumentation* / Q000379:methods; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D011673:Pulsatile Flow; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000517:prevention & control; D015203:Reproducibility of Results; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods
keywords: CT; Dynamic perfusion; Myocardial perfusion; Phantom