Study On Selections Of Different Reference Vessel Groups By Multi-Slice Spiral CT Perfusion On Patients With Nasopharyngeal Carcinoma After Radiation Therapy

Objective Investigate the affect of CT perfusion by different reference vessel groups in patients with Nasopharyngeal carcinoma (NPC) after radiation therapy, and explore the feasibility of substitution in these groups.Methods 30 patients with NPC after radiation therapy were divide into two groups with respect to pathologic finding as reference standards, recurrences(n=19) and fibrosis(n=11). All patients underwent CT perfusion scans, and were calculated the CT parameters by different arterial input and vein output, were internal carotid artery-internal jugular vein, external carotid artery-mandibular vein and external carotid artery-internal jugular vein respectively. The differences of the CT parameters between local recurrence and fibrosis were compared by rank sum test. With the help of receiver operating characteristic curve (ROC), the sensitivity and specificity were determined by maximal Youden index, and the diagnostic efficiency were compared by the ROC area under curve (AUC).Results The differences of BF and BV between local recurrence and fibrosis were statistically significant (P<0.05) but MTT and PS had no (P> 0.05). In ICA-IJV group,AUC of BF,BV,MTT,PS were 0.909,0.947,0.677,0.703, respectively. BF,BV,MTT,PS in ECA-RTV group were 0.938,0.967,0.648,0.679 respectively,and those in ECA-IJV group were 0.861,0.890,0.641,0.656 respectively. However, AUC of each parameters of three groups had no significant difference (P> 0.05).Conclusion The diagnosis efficiency of BF and BV calculated by three pairs reference vessels are equal; so all of the three groups of vessels may substitute each other in CT perfusion.