| ObjectiveTo explore the diagnostic value of multislice spiral CT scan, dynamic enhanced scan,and perfusion scan distinguish between malignant and benign based on surroundingcharacteristics, internal features, enhanced features and perfusion parameters of SPN. Andpreliminary study in diagnostic pathway of SPN based on the multislice spiral CT.MethodsSPN patients underwent CT scan, or dynamic contrast-enhanced scan, or perfusion scanusing the GE Lightspeed16-slice CT. We adopted postprocessing technique by GE ADW4.3workstation and Perfusion3-body tumor software to analysis of nodules. Statistical analysisthe parameters, including a variety of CT scan signs, the maximum enhanced degree after CTenhanced, the enhanced degree at each time point and draw time-density curve(TDC), as wellas the blood flow(BF), blood volume(BV), mean transit time (MTT) and permeabilitysurface(PS) values and time-density curve(TDC) of SPN with CT perfusion, to obtain thestatistical significance parameters in the diagnosis of benign and malignant SPN bycalculating the sensitivity, specificity, positive predictive value, and negative predictivevalue.Result1．60patients with SPN underwent CT scan, surgical and pathological findings as thediagnostic criteria, the statistically significant (P<0.05) single sign were lobulated, spiculated,pleural indentation, edge burrs and vessel convergence, in which the first three diagnostic performance is higher. Area under the ROC curve, sensitivity, specificity, accuracy, positivepredictive value and negative predictive value respectively were: lobulated sign0.771,75.0%,79.2%,76.7%,84.4%,67.9%, spiculated sign0.694,72.2%,76.7%,70.0%,82.3%,64.9%,pleural indentation sign0.660,44.4%,87.5%,61.7%,84.2%,51.2%. The area under theROC curve, sensitivity, specificity, accuracy, positive predictive value and negativepredictive value of combinations signs respectively were: lobulated sign+spiculated sign0.743,61.1%,87.5%,71.7%,87.9%,60.0%, lobulated sign+pleural indentation sign0.674,38.9%,95.8%,61.7%,93.3%,51.1%, spiculated sign+pleural indentation sign0.646,33.3%,95.8%,75.0%,92.2%,48.9%, lobulated sign+spiculated sign+pleural indentation sign0.653,30.6%,100%,58.3%,100%,48.9%. The diagnostic efficacy of the single signs andcombination signs were not statistically different, the Z test for area under ROC curve werenot significant difference among groups(P>0.05).2．53patients with SPN underwent dynamic contrast-enhanced CT scan, comparison ofbenign and malignant SPN at each time point that30seconds was statisticallysignificant(P<0.05). Comparison of benign and inflammatory SPN at each time point that30,60,120,180,240seconds were statistically significant(P<0.05). Comparison of malignantand inflammatory SPN at each time point that60,120,180,240seconds were statisticallysignificant(P<0.05). For benign SPN, there were not statistically different between theenhanced degree at each time point and the maximum enhanced degree after CTenhanced(P>0.05). For inflammatory SPN, there were statistically different between themaximum enhanced degree after CT enhanced and the enhanced degree at15,30seconds(P<0.05). For malignant SPN, there were statistically different between themaximum enhanced degree after CT enhanced and the enhanced degree at15,30,60seconds(P<0.05). When the CT enhanced degree was greater than15HU as the malignantSPN diagnostic threshold, the area under the ROC curve, sensitivity, specificity, accuracy,positive predictive value, negative predictive values were0.699,96.9%(31/32),42.9%(9/21), 75.5%(40/53),72.1%(31/43),90.0%(9/10), the CT enhanced degree was15HU-60HU as themalignant SPN diagnostic threshold, were0.866,87.5%(28/32),85.7%(18/21),86.8%(46/53),90.3%(28/31),81.8%(18/22), the CT enhanced degree was smaller than60HU as themalignant SPN diagnostic threshold, were0.667,90.6%(29/32),42.9%(9/21),70.4%(38/53),69.1%(29/42),75.0%(9/12).3．42patients with SPN underwent perfusion scan, the BV and PS of the malignant SPNwere higher than the benign SPN(P <0.05), BF and MTT were not significantdifference(P>0.05). The BF, BV and PS of the malignant SPN and inflammatory were higherthan the benign SPN(P <0.05), the perfusion parameters were not significant differencebetween malignant nodules and inflammatory nodules. When BV≥5ml/100g as themalignant diagnostic threshold, the sensitivity, specificity, positive predictive value, negativepredictive values were87.5%(21/24),72.2%(13/18),80.7%(21/26),81.3%(13/16). When PS≥15ml/(min·100g) as the malignant diagnostic threshold, the sensitivity, specificity, positivepredictive value, negative predictive values were91.8%(22/24),66.7%(12/18),78.6%(22/29),85.7%(12/14). When BV≥5ml/100g and PS≥15ml/(min·100g) as the malignant diagnosticthreshold, the sensitivity, specificity, positive predictive value, negative predictive valueswere95.8%(23/24),83.3%(15/18),88.5%(23/26),93.8%(15/16). The malignant,inflammatory and benign nodules were different TDC shape. The malignant nodules weretype I curve, inflammatory nodules were type II curve, and benign nodules were III typecurve.4．All42patients with SPN underwent CT scan, dynamic enhanced and perfusion scan,the statistically significant (P<0.05) single sign were lobulated, spiculated, pleuralindentation. Area under the ROC curve, sensitivity, specificity, accuracy, positive predictivevalue and negative predictive value respectively were: lobulated sign0.701,62.5%,77.8%,69.0%,80.0%,60.9%, spiculated sign0.681,75.0%,61.1%,69.0%,72.0%,64.7%, pleuralindentation sign0.674,45.8%,88.9%,64.3%,84.6%,55.2%. The area under the ROC curve, sensitivity, specificity, accuracy, positive predictive value and negative predictive value ofcombinations signs respectively were: lobulated sign+spiculated sign0.667,50.0%,82.3%,79.0%,55.2%, lobulated sign+pleural indentation sign0.688,37.5%,100%,100%,54.5%,spiculated sign+pleural indentation sign0.632,37.5%,88.9%,81.8%,51.6%, lobulatedsign+spiculated sign+pleural indentation sign0.625,25.0%,100%,100%,50.0%. There weregood accuracy in the diagnosis of benign and malignant SPN by dynamic enhanced CT scanand CT perfusion imaging, the area under the ROC curve, sensitivity, specificity, accuracy,positive predictive value and negative predictive value were0.910,87.5%,94.4%,95.4%,85.0%and0.813,79.2%,83.3%,86.3%,75.1%. The Z test of the area under the ROC curveof combination signs, dynamic enhanced CT and perfusion shown that there were statisticallysignificant between the combination signs and the dynamic CT(P<0.05), others were notstatistically significant. Area under the ROC curve, sensitivity, specificity, accuracy, positivepredictive value and negative predictive value of combination of dynamic enhanced and CTscan respectively were: the maximum enhanced degree after CT enhanced+lobulatedsign+spiculated sign0.681,41.7%,94.4%,90.8%,54.9%, the maximum enhanced degreeafter CT enhanced+lobulated sign+pleural indentation sign0.667,33.3%,100%,100%,53.0%, the maximum enhanced degree after CT enhanced+spiculated sign+pleuralindentation sign0.667,33.3%,100%,100%,53.0%, the maximum enhanced degree after CTenhanced+lobulated sign+spiculated sign+pleural indentation sign0.604,20.8%,100%,100%,48.7%. Area under the ROC curve, sensitivity, specificity, accuracy, positivepredictive value and negative predictive value of combination of perfusion and CT scanrespectively were: perfusion parameters+lobulated sign+spiculated sign0.688,37.5%,100%,100%,54.8%, perfusion parameters+lobulated sign+pleural indentation sign0.667,33.3%,100%,100%,53.0%, perfusion parameters+spiculated sign+pleural indentation sign0.639,33.3%,100%,100%,53.0%, perfusion parameters+lobulated sign+spiculated sign+pleuralindentation sign0.604,20.8%,100%,100%,48.7%. Area under the ROC curve, sensitivity, specificity, accuracy, positive predictive value and negative predictive value of combinationof dynamic enhanced CT scan, perfusion and CT scan respectively were: the maximumenhanced degree after CT enhanced+perfusion parameters+lobulated sign+spiculated sign0.646,29.2%,100%,100%,51.5%, the maximum enhanced degree after CTenhanced+perfusion parameters+lobulated sign+pleural indentation sign0.646,29.2%,100%,100%,51.5%, the maximum enhanced degree after CT enhanced+perfusionparameters+spiculated sign+pleural indentation sign0.646,29.2%,100%,100%,51.5%, themaximum enhanced degree after CT enhanced+perfusion parameters+lobulatedsign+spiculated sign+pleural indentation sign0.583,16.7%,100%,100%,47.4%.Conclusion1.For most SPN, CT scan can identify benign and malignant. There were not statisticallysignificant difference in the diagnostic performance between individual signs andcombinations signs, but with the increase of the typical signs, the reliability of the diagnosismalignant and postive predictive value increases.2.Multi-phase dynamic contrast-enhanced CT has a higher value in differential diagnosisbenign, malignant and inflammatory SPN. When the maximum enhanced degree in the rangeof15-60HU as the diagnosis of malignant threshold, its accuracy as high as86.8%.30seconds,60seconds and120seconds after inject contrast is more reasonable as the scan timepoint.3.CT perfusion imaging also has a higher value in identify benign and malignant SPN.When BV≥5ml/100g and PS≥15ml/(min·100g) as the diagnosis of malignant threshold,the positive predictive value is88.5%. However, it lack specificity for differentiatingmalignant and the inflammatory SPN.4.Diagnosis of benign and malignant performance by CT dynamic scanning and CTperfusion scan were higher than CT scan. There were more meaningful for atypical lesionsusing multi-phase dynamic CT scan combined with CT scan or CT perfusion scan. Multi-phase dynamic CT scan combined with CT scan in the clinical application is moreconvenient and reasonable. |
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