Preliminary Evaluation Of Dual-energy Dual-phase Enhanced CT For The Esophageal Cancer

Part one Evaluation of esophageal lesions display capability with Dual-energy dual-phase Enhanced CTobjective: To evaluate dual-phase dual-energy CT enhanced displaying capabilities of esophageal lesionsmethods:38 cases of esophageal cancer patients (24 men, 14 women, aged 53 to 76 years, the average age was 65 years) perform arterial and venous phase dual-energy scan, a total of 38 lesions, 8 cases located in the upper thoracic, 21 cases located in the middle chest section, 9 cases located in thoracic. All lesions were confirmed by operative pathology.All patients used dual-source CT (SOMATOM definition flash; Siemens) scan.After injecting contrast agents in the 25s, 65s, all patients underwent dual-energy scanning in one breath. A tube voltage was 100KV, B tube voltage was 140KV. Qualitative analysis of images was completed by two high qualification radiologist.The presence of the tumor was defined as limitations enhanced with or without the limitations of wall thickening. The display formats of lesions formats in each issue and each sequence (100KV, 140KV, 120KV fused image) were divided into the following three types. 1: not identifiable, focal enhancement with or without minimal (<1 cm) wall thickening and focal mass lesion or obvious (>1 cm) wall thickening. A quantitative analysis was performed by another physician who knows the localization of the lesion throughout operation or endoscopy. Measure the CT value of lesions and normal esophago in each issue and each sequence. The localization of the lesions was compared with the result of the operation and endoscopy. According three display types counts, analysis the detection of lesions capacity. Calculation the mean, standard deviation (SD) of dual-phase CT value and CT value of the difference between normal esophageal lesions. Comparison the CT values difference of the arterial phase and venous phase disease and between tumor and normal esophageal. Comparison of arterial and venous phase images with different voltage difference between the CT normal esophageal lesions. Two groups were compared using paired t test. P value less than 0.05 was considered statistically significant difference. According to Grade level the image and the sequence comparison between arterial and venous whether the quality of the lesions showed a statistically significant difference. Statistical Methods the Wilcoxon rank sum test.Results:1 Detection rate35 cases in Arterial lesions were found (92%), 33 lesions were found in venous phase (87%). 100KV arterial phase images and the fused image found all 35 cases, 140KV arterial phase mages 32 cases were found of 35 cases. Of all 33 in cases was found at 100KV vein phase and the fused image. And at 140KV image,33 cases were found in 32 cases. Type 2 and type 3 were shown the excellent display capability in the 100KV and the fused image sequences.2 Comparison of lesion contrastOnly 34 cases of 38 lesions CT value were measured, Arterial phase the difference CT value of normal esophageal lesions and is greater than venous phase, was statistically significant (P <0.05). In arterial phase 100KV the CT value difference and is greater than 140 KV and 120KV fusion image (P <0.05). 120KV CT value difference of the image lesions was greater than 140KV (P <0.05).Conclusion:1 Low kV image lesion detection rate of esophageal lesions and image contrast greater than other kV.2 Artery phase lesion detection rate of esophageal lesions and image contrast greater than the venous phase . The part two Diagnostic value of Enhanced dual-phase dual-energy CT for T staging of esophageal cancerObjective: To evaluate the enhanced dual-phase dual-energy CT for T staging of esophageal cancermethods:38 cases of esophageal cancer patients (24 men, 14 women, aged 53 to 76 years, the average age was 65 years) perform arterial and venous phase dual-energy scan, a total of 38 lesions, 8 cases located in the upper thoracic, 21 cases located in the middle chest section, 9 cases located in thoracic . All lesions were confirmed by operative pathology.All patients used dual-source CT (SOMATOM definition flash; Siemens) scan.After injecting contrast agents in the 25s, 65s, all patients underwent dual-energy scanning in one breath. A tube voltage was 100KV, B tube voltage was 140KV. Select the 100KV arterial axial images measuring wall thickness of esophageal. Chose vein phase low kV image observe the adjacent organs encroachment. standard of Enhanced CT esophageal cancer staging: T1 period: esophageal wall thickening≤5mm with focal enhancement; T2 stage: wall thickening (5 ~ 10mm), or≥10mm with not fully enhancement of wall,without foreign invasion ; T3 period: wall thickening (≥10mm) or≤10mm with fully-hardened of the wall and with the disappearance of fat space around the structure; T4 period: wall thickening with adjacent organ involvement. CT staging results were statistically compared with the pathological stage, calculated on the diagnostic accuracy.Results: Diagnostic accuracy of the stage was T1 66.7%, T2 of 66.7%, T3 of 64.7%, T4a period of 50%, T4b of 80.0%. The total accuracy was 60.5%. A Tis case of was missed diagnosis.Conclusion:1 Dual energy scanning can get Preoperative accurate positioning, high accuracy of preoperative T staging. 2 arterial phase low-kV images can help to reduce the thickness measurement error of the esophagus. 3 low kV images of venous phase lesions can get higher diagnostic accuracy of adjacent organs invade.Part three The control study about dual-phase dual-energy CT and barium meal measure the length of esophageal cancerObjective:Discuss the value of the dual-energy CT and barium meal measuring the length of esophageal cancer.Materials:25 cases of esophageal cancer patients perform arterial and venous phase dual-energy scan, a total of 25 lesions. All lesions were confirmed by operative pathology.All patients used dual-source CT (SOMATOM definition flash; Siemens) scan.After injecting contrast agents in the 25s, 65s, all patients underwent dual-energy scanning in one breath. A tube voltage was 100KV, B tube voltage was 140KV. The methods of CT measurement: 1. 1.select 100KV arterial sagittal plane MPR images measure the length of esophagus; 2. Esophageal wall thickening with or without the focal enhancement is to be as the extent of the disease invasion;3 when the wall thickening is not obvious enhancement, measuring the length of abnormal enhancement;Esophageal barium meal: Esophageal imaging uses digital fluoroscopic .By the high qualification diagnostic radiologist recorded the length of esophageal lesions.Length measurement of Lesions specimen and length calculation of real tumor: The length of the measured Lesions specimen after surgery measured the length of real tumors by the contraction rate, the length of the tumor about Ls=Lp/0.8. the length of Esophageal Cancer CT and barium meal measurement evaluates the compliance degree based on the value between the two measurement methods and Pathology specimen length Ls .Mean of samples were compared using two sample t-test.χ2 test for coincidence between two methods of comparison group. P value <0.05 was considered statistically significant difference.Results:1 Comparison of two sample t-test showed the measured length of the CT is greater than the length of solid tumors, Barium meal is less than the length of the measured length of solid tumors. Statistics has significant differences.2 The Accuracy rate of CT (52.0%) is lower than the barium meal's (60.0%).3 The severe incompliance rate of CT 25% is higher than the barium meal's 30%.Conclusion:1 The Accuracy rate of barium meal of esophageal length higher than Enhanced dual-energy CT.2 Measuring dual-energy enhanced low-kV scanning arterial phase images can improve the accuracy of length measurement of esophageal cancer.