Preliminary Research of MSCT Perfusion Imaging in Normal Pulmonary Parenchyma with Breath-hold

Objective To explore the perfusion value of pulmonary parenchyma in breath-hold at spiral CT perfusion first-pass phase.Methods 60 healthy volunteers were divided into 3 groups based on the injection velocity and were examined by chest plain CT scan first,then the level of the hilum of lung was scanned after the intravenous injection of 40 ml of contrast given at 3 ml/s、4 ml/s or 5 ml/s.Thirty 0.5 s duration and 0.5 s interval scans were performed from 0 to 30 s after injection.Time-density curves were then drawn from both lung and pulmonary artery using regions of interest(ROIs).Following previous work,pulmonary parenchyma perfusion was calculated as the peak upslope of the tissue time-density curve divided by peak pulmonary artery enhancement.Results Pulmonary parenchyma perfusion of healthy Chinese with the injection velocity at 3 ml/s,4 ml/s and 5 ml/s respective was(1.41±0.26)(x±s)ml·min-1·ml-1,(1.01±0.14)ml·min-1·ml-1 and(1.08±0.12)ml·min-1·ml-1.The difference of the perfusion between 3 ml/s and 4 ml/s or 5 ml/s was of marked statistical significance,and the difference between later two was no statistical significance.Conclusion Measuring the perfusion of lung with breath-hold by MSCT is feasible,and the suitable injection velocity is 4 ml/s.