Dynamic Contrast-enhanced Ct Differential Of Solitary Pulmonary Nodules Of Benign And Malignant

Objective To detect the bloody flow mode and the perfusion feature of solitary pulmonary nodules (SPN), compare the diagnostic performance of combined scores through multiple parameters for the differentiation of benign and malignant SPN.Methods 52 patients with proved SPN underwent the perfusion scan of dynamic CT ( with series Dynmulti7. 2Bls, 80Kv, 250mAs, collimation 1. 2mm, slice 28.8mm, cycle time 1s, Omnipaque 300 50ml with the injective rate 5ml/s , the interval time 1s, duration time 30s, , and delay 4s) and the dynamic scan( with interval time 15s from 45s for five scan, then, and 30s from 120s for fourteen scan). Images of perfusion scan were post-processed by the body perfusion software. Differences of parameters of perfusion CT between benign and malignant nodules were compared, and computed combined scores of each nodule to diagnose SPN.Results Some parameters in benign nodules were revealed greater frequency than those in malignant ones, involved enhanced values were larger or equal than the cutoff value in continuous three of time spots of 20s, 22s, 24s, 25s, 26s, 28s, 30s, 34s), the margin enhancement, non-enhancement, those enhanced identically with pulmonary artery, even low permeability parameter images, and even low Patlak R square parameter images so on. Parameters in malignant nodules were revealed greater frequency than those in benign ones, involvedthe value of Patlak R square was larger than 45.1, the whole enhancement, the patchy enhancement, and those enhanced identically with systematic circulation so on. The combined score of above-mentioned parameters were computed, and the malignant nodules were diagnosed by combined scores. If selected the score larger than 0.5 as the cutoff value to diagnose the malignance, the sensitivity and speciality were 94.3 % and 41.2 % respectively.Conclusion Perfusion scan of dynamic CT is a feasible method to evaluate the bloody flow mode and perfusion feature of SPN, and the method of combined scores is a easy way to improve the diagnostic performance.