Clinical Application Of Dual-source CT Dual-energy Technique In Nasal Cavity And Paranasal Sinus Masses

Part ?Influence of optimal single energy combined with SAFIRE on image quality of nasal cavity and paranasal sinus massesObjective:To investigate the influence of dual energy CT optimal single energy imaging combined with SAFIRE on image quality of nasal cavity and paranasal sinus massesMethods:60 cases of nasal cavity and paranasal sinus masses confirmed by pathology were retrospectively analyzed.All the patients underwent conventional CT plain scan and dual energy CT enhanced scan.The images of arterial and venous phases were reconstructed by traditional filtering back projection(FBP)and iterative reconstruction(SAFIRE),and the latter was transferred into the Monoenergetic software and processed.Three groups of images were obtained(Group A:optimal single energy/SAFIRE,Group B:linear fusion image/FBP,Group C:linear fusion image/SAFIRE).Subjective evaluation(image quality score,focus significance score)and objective evaluation[Signal noise ratio of lesions(SNR),Contrast noise ratio of lesions(CNR),background noise(SD)]were compared among the three groups.To compare the optimal single energy value between arterial phase and venous phase.Results:?The SNR and CNR,image quality score and focus significance score of arterial phase and venous phase in group A and C were significantly higher than those in group B,and the SD was lower than that in group B(P<0.05).?There was no significant difference in SNR,CNR,SD and image quality score between group A and group C(P>0.05).The significant score of focus in group A was higher than that in group C(P<0.05).?In group A,the focus significant score of venous phase was higher than that in arterial phase(P<0.05).?There was no significant difference in the optimal single energy value between the arterial and venous phases(P>0.05),the optimal single energy was(65.38±0.87)KeV.Conclusions:65kev is the optimal single energy value in dual-source CT dual-energy scan of nasal cavity and paranasal sinus masses.The optimal single energy combined with SAFIRE technique can significantly reduce the image noise,improve the contrast of the focus,increase the detail information,and be more helpful for the analysis and diagnosis of nasal cavity and paranasal sinus massesPart ? The value of Dual-source CT iodine content and iodine overlay in differentiating nasal cavity and paranasal sinus massesObjective:To investigate the value of iodine content and iodine overlay in dual source CT in differentiating nasal cavity and paranasal sinus masses.Methods:The clinical data and scanning methods were the same as the first part.The thin-layer data of SAFIRE reconstruction in arterial and venous phases were transferred into dual-energy Liver VNC software to obtain the iodine map of the lesion.The iodine concentration(IC)and overlay value of the solid part of the lesion were measured in iodine imaging,and the CT value of the solid part of the lesion was measured on the dual-phase fusion image.According to the pathological results,they were divided into benign group(33 cases)and malignant group(27 cases).Benign group was divided into angiogenic tumor(7 cases)and non-angiogenic tumor(26 cases).The IC,overlay value and CT value of the lesions in two groups were compared by independent sample t-test,and the ROC curve of each parameter were drawn,and the area under the curve(AUC)was compared to evaluate the diagnostic effectiveness.Results:? In arterial phase and venous phase,there was no significant difference in the IC,overlay value and CT value of benign angiogenic tumor and malignant group(P>0.05).?The parameters of benign non-angiogenic tumors were significantly lower than those of malignant ones(P<0.05).Arterial phase:the IC,Overlay value and CT value of benign non-angiogenic tumors were 0.76±0.50?21.01 ± 18.36?54.47± 13.90,respectively.The malignant group were 1.60±0.67?37.62±16.62?72.24±15.78,respectively.Venous phase:the IC,Overlay value and CT value of benign non-angiogenic tumors were 0.94±0.75?26.14±19.94?60.68±18.96,respectively.The malignant group were 1.93±0.66?45.86±15.53?81.54±13.73,respectively.?In arterial phase:the AUC of the IC,Overlay value and CT value of the lesion were 0.868?0.840?0.835,respectively.The venous phase were 0.859?0.816?0.829,respectively.Among them,the diagnostic efficiency of IC in venous phase was the best.The sensitivity,specificity and accuracy of 1.375 mg/ml were 88.9%,84.6%and 86.8%,respectively.Conclusions:The iodine concentration,overlay value and CT value of benign angiogenic tumors of nasal cavity and paranasal sinus overlap with malignant tumors.The diagnosis should be combined with routine morphological features.Iodine concentration can more accurately reflect the blood supply of nasal cavity and paranasal sinuses tumors,and is helpful for differential diagnosis of malignant tumors and benign non-angiogenic tumors.Part III The value of optimal single energy CT and energy spectrum curve in differential diagnosis of non-angiogenic masses in nasal cavity and paranasal sinusObjective:To explore the value of optimal single energy CT value and slope of energy spectrum curve of dual source CT in differential diagnosis of non-angiogenic masses in nasal cavity and paranasal sinusMethods:7 cases of angiogenic masses in the second part were removed,and a total of 53 cases were included in the third part.The scanning methods were the same as the first part.Diagnosis of benign and malignant lesions based on the conventional morphological manifestations of the lesions.The thin-layer data of SAFIRE reconstruction in arterial phase and venous phase were transferred into Monoenergetic software to obtain the CNR curve and energy spectrum curve of the lesion.The optimal CNR single energy CT value(CTose)and the slope of energy spectrum curve(K)of the solid part of the lesion were measured.The CT value of the solid part of the lesion was measured in the dual-phase fusion image.According to the pathological results,they were divided into benign group(26 cases)and malignant group(27 cases)to evaluate the diagnostic efficacy of routine morphological analysis.The values of CTose,K and CT were compared between benign group and malignant group,and the ROC curves of each parameter were drawn.The diagnostic efficacy was evaluated by comparing the area under the curve with(AUC).Results:?The sensitivity,specificity and accuracy of routine morphological diagnosis were 74.1%,84.6%and 79.2%,respectively.?Arterial phase:the CTose value,K value,CT value of benign group were 61.91±25.62,0.92±0.69,56.56±16.67,respectively.The malignant group were 80.16±16.07,1.97±1,18,67.85±11.41,respectively.Venous phase:the CTose value,K value,CT value of benign group were 68.25±26.60,1.26±0.78,62.57±19.98,respectively.The malignant group were 95.31±16.72?2.50±0.95,79.08±12.61,respectively.The parameters of malignant group in arterial phase and venous phase were higher than those in benign group(P<0.05).?In arterial phase:the AUC of the CTose value,K value,CT value were 0.813,0.883,0.736,respectively.The venous phase were 0.841,0.885,0.777,respectively.Among them,the AUC of K value in venous phase was the largest(0.885).Using K=1.77 as diagnostic threshold,the diagnostic sensitivity and specificity and accuracy were 88.5%and 88.2%and 88.3%,respectively.Conclusions:The optimal single energy CT value and the slope of the energy spectrum curve of dual-source CT can more accurately reflect the blood supply and tissue difference of the lesions,which is helpful to improve the accuracy of qualitative diagnosis of non-angiogenic masses in nasal cavity and paranasal sinuses.