The Applications Of Dual Energy Dual-phase Enhanced Scan In The Diagnosis Of Esophageal Cancer By Dual-source CT

Part One The evaluation of optimal monochromatic energy image in thediagnosis of esophageal cancerObjective: To acquire the optimal monochromatic energy which displaysthe esophageal cancer best by using dual-source dual-energy CT in dual-phaseenhanced scan.And to evaluate the ability of the optimal monochromaticenergy image in two phases to display the lesions.Methods:37patients(26men,11women, age range34-78, mean age was60.92±9.16) with esophageal cancer from May2011to December2012, whounderwent dual-energy dual-phase scan by Siemens second-generation dual-source CT were collected.“A” tube voltage was80KVp, and “B” tube voltagewas140KVp, using CARE DOSE4D technique. The thorax was scanned at25ths(arterial phase) and60ths(venous phase) seperately after injection ofcontrast medium70ml(300ml/mg,3ml/s, iohexol).Using the “Monoenergetic”software to acquire the curves of the lesions, the normal esophageal wall andthe image noise. After calculating we acquired the optimum monochromaticenergy which had the highest CNR and the lowest image noise.Results: The optimum monochromatic energy was at70keV in bothphases.In arterial phase, the maximum value of CNR and SNR of the lesionwas at70keV, and was1.64±0.85,3.62±1.44, respectively.The minimum valueof the image noise was at70keV, and was15.57±3.72HU. In veneous phase,the maximum value of CNR and SNR of the lesion was at70keV, and was1.11±0.67,4.08±1.47, respectively. The minimum value of the image Noisewas at70keV, and was17.11±3.71HU.At70keV level the CNR value of the lesion in arterial phase is higherthan that of in venous phase,but the SNR value of the lesion in venous phase ishigher than that of in arterial phase. Conclusion:The optimum monochromatic energy is at70keV.At70keV，the arterial phase had a superior to display and detect the lesions, and thevenous phase had a superior to reveal the inner structures of the lesions and itsrelations surrounding tissues. Part Two The value of optimal monochromatic energy image in arterialphase in measuring the Length of esophageal cancerObjective: To evaluate the the capability of optimal monochromaticenergy image in arterial phase to measure the tumor length of esophagealcancer.Methods:44patients (36men,8women, age range47-78, mean age was61.91±7.35) with esophageal cancer from May2011to Febrary2013in ourhospital who underwent dual-phase dual-enegy scan by dual-source CT werecollected, totally about44lesions.“A” Tube voltage was80KVp,“B” tubevoltage was140KVp,using CARE DOSE4D technique.After injectingcontrast agents70ml(300ml/mg,3ml/s,iohexol), patients were scaned the indual-energy mode at the25ths(arterial phase) and60ths(venous phase).Thethe optimal monochromatic energy images in arterial phase(25s) were used tomeasure the lengths of the lesions.All the patients were underwent endoscopybefore surgery too,and the lengths of the tumor were measured.Usingpathological specimen length to calculate the the actual tumorlengths.Compared the lengths measured by the optimal monochromatic energyimage in arterial phase with the actual tumor lengths.Result: The average length measured by the optimal monochromaticenergy image was5.15±2.30cm, which was longer than the actual tumorlength(4.41±2.35cm).The difference between them had statistical significance.The accuracy of tumor length predictions from70keV compared to theactual tumor length was59.1%(26/44). The severe inconsistent rate was 44.4%.Conclusion: The average length measured by the optimal monoch-romatic energy image in arterial phase was longer than the actual tumoraverage length.Tumor lenths measured by the optimal monochromatic energyimage in arterial phase improved the consistent rate and decreased the severeinconsistent rate. Part Three Evaluation of the optimal monochromatic energy image invenous phase for T staging of esophageal cancerObjective: To evaluate the value of the optimal monochromatic energyimage in venous phase for T staging of esophageal cancer.Methods:70patients (52men,18women,age range41-79, mean age was62.44±8.35) with esophageal cancer from May2011to March2013in ourhospital who underwent dual-phase dual-energy enhanced scan by dual-sourceCT were collected,totally about70lesions.“A” Tube voltage was80KVp,“Btube voltage was140KVp,using CARE DOSE4D technique.After injectingcontrast agents70ml (300ml/mg,3ml/s, iohexol),scaned the patient in dual-energy mode at the25ths(arterial phase) and60ths(venous phase). Using1mmimages at the the optimum monochromatic energy in venous for T staging ofesophageal cancer.The alike refined-standard of T staging for CT waschosen,conmpared with pathological results to test its accuracies.Results: Diagnostic accuracies of the optimal monochromatic energyimage in venous phase for T staging was: T1,50%; T2,50%; T3,88.6%; T4a,83.8%. T4b,80%. The total accuracy was77.1%.Conclusion: The optimal monochromatic energy image in venous phaseimproved the accuracy of T staging, especially improved the accuracy forT3.And The monochromatic energy image in venous phase had an advantageto display its inner structures and its relations with surrounding tissues. Part Four Applications of SAFIRE combined with low-voltage bydual-source CT in low dose enchanced scan of easophageal cancerObjective: To evaluate the value of SAFIRE (sonogram-affirmediterative reconstruction) technique combined with low-voltage in theeasophageal cancer enhanced scan by using dual source CT.Methods: Those patients were selected randomly from two groups ofpatients,from January2013to March2013,all of them were scaned bydual-energy CT.From each group we chosed30patients randomly,totallyabout60patients.(32men,28women, age range48-79, mean age was63.98±7.80). There are totally60lesions, all of them were detected by CTscan.30patients were from group A, which tube voltage was100KVp.Theother30patients were from group B, which tube voltage was120KVp. Bothgroups adopted CARE DODE4D technigue.In group A,used FBP andSAFIRE to reconstruct1mm100KVp-FBP image and100KVp-SAFIREimages.Then compared the difference of CNR、SNR of the lesions and imagenoise between the two series.In group B used FBP to reconstruct1mm120KVp-FBP images，then compared the difference of CNR、SNR of thelesions and image noise between100KVp-SAFIRE and120KVp-FBP imagesResults: The SNR, CNR of the lesions and the image noise of100KVp-FBP was2.68±0.93,1.31±0.81,23.47±4.69HU. The SNR,CNR ofthe lesions and the image noise of100KVp-SAFRIE images was3.50±1.25，1.76±0.93,16.67±4.23HU,respectively.There were statistically significantdifferences.The SNR,CNR of the lesions and image Noise of120KVp-FBPimages was1.43±0.70,2.65±0.80,17.92±4.90HU.Except for SNR,there wereno statistically significant differences between100KVp-SAFRIE and120KVp-FBP.The100KVp-SAFRIE images can reduce the effective radiationdose about45.1%(P<0.05), but not at the expensive of lowing the imagequality. Conclusion: The SAFRIE technique combinged with low-voltage ineasophageal cancer enhanced scan can reduce the effective adiation dosegreatly, but not at the expensive of lowing the image quality...