Study Of The Value Of The Dual-source CT’s MPR In The Preoperative Evaluation Of Esophageal Cancer Lymph Nodes Metastasis And The Patients’ Effective Dose

ObjectiveTo evaluate the application values of multi-plane reformation(MPR)reconstruction of the dual-source CT in the diagnosis of lymph node metastasis of esophageal cancer.Meanwhile,the differences in doses in patients with esophageal carcinoma,who underwent the dual-source CT dual-energy mode,dual-source CT single energy mode,and single-source CT,were investigated by using the phantom.MethodsPart 1: 37 patients who were diagnosed with esophageal cancer were examined with preoperative contrast-enhanced multi-slice CT(MSCT).The raw data were analyzed independently by the MPR reconstructed view group and routine axial view group to evaluate lymph nodes within Group No.105,Group No.106(No.106 rec,No.106 tb,No.10 6pre),Group No.107,Group No.108,Group No.110,Group No.111,Group No.2,Group No.7 of those 37 patients.The standard of lymph node metastasis included the shorter line larger than 7mm or inhomogeneous enhancement of the lymph node or fusion lymph node.The sensitivity,specificity and Younden index were used to assess the application values of MPR for the diagnosis of lymph node metastasis of the esophageal cancer.All the dissected lesions were confined by the histopathology and classified by the <Japanese Classification of Esophageal Cancer,tenth edition>.Part 2: According to the 103 publications of the ICRP,TLDs were placed in the 38 target holes of different organs or tissues of the phantom.The experiment was carried in the same scan condition by the dual-source CT dual-energy mode,dual-source CT single energy mode,and single-source CT.The adsorbed doses in different organs or tissues were measured and then the effective doses in the patients were calculated and statistically analyzed in this work..ResultsPart 1: 366 lymph nodes were dissected during the operations,in which 72 malignant lymph nodes were confirmed by pathology.360 lymph nodes were found in MPR reconstructed view group and 80 malignant lymph nodes were detected,in which 60 lymph nodes were proved to be true positive.327 lymph nodes were found in routine axial view group and 42 malignant lymph nodes were detected which were proved by pathology.The sensitivity,specificity and Younden index of the MPR reconstructed view group were 83.3%,93.1%,75%,95.8%,0.765,and those in the routine axial view group were 58.3%,88.4%,55.2%,89.6%,0.467 correspondingly.Part 2: The absorbed doses in different organ or tissue in the single-source 64-slice CT,dual-source 64-slice CT single energy mode,and dual-source 64-slice CT dual-energy mode ranged from 0.126 to329.7 mGy,0.114 to317.8 mGy,and 0.123 to321.2 mGy,respectively.The lowest organ adsorbed dose was gonad and the bone tissue was the highest.The effective doses of patient in the three groups were 26.9 mSv,26.1mSv,and 26.8mSv.ConclusionThe application of MPR in the preoperative contrast-enhanced MSCT has highly sensitivity and,specificity,which plays a significant role in the diagnosis of node metastasis of esophageal cancer lymph node metastasis.It’s also meaningful for the preoperative evaluation of esophageal cancer.Meanwhile,the patient’s dose of three scan mode are basically the same.In this regard,when we met the need in the clinic,the best CT examination scheme should be chosen,without think about the patient’s dose.