e thickness and axial MPR images with 7 mm reformatted slice thickness is the optimal protocal.

Objective To classify the accessory fissures and assess the frequency of accessory fissures of the lung by 64-slice spiral CT (MSCT). Methods Of 2664 patients, 847 patients were included in this study excluding the patients with pulmonary parenchymal distortion, pleural disease or lobectomy. Allvolume raw data with a slice thickness of 0.6 mm were reformatted in sagittal and coronal orientations with 3 mm thickness and the accessory fissures were assessed. Results A total of 177 accessory fissures in 144 patients (17.0%) were detected. Most of the accessory fissures were incomplete except 10 fissures on the right lung (8.2%) and 2 fissures on the left lung (3.6%) were complete. The most common fissurewas the superior accessory fissure on the right low lobe (n = 112,13.2%) ,followed by the left minor fissure (n= 51,6.0%), the right inferior accessory fissure( n = 6,0. 7% ), the left superior accessory fissure ( n =4, 0.5%), the azygos fissure (n = 3,0.4%) and the accessory fissure on the right upper and middle lobe(n = 1,0.1%). Conclusion 64-slice CT is an efficient method to observe and classify the accessory fissures of the lung with MPR technique and can provide reliable and useful imaging information for the clinician.

Objective To evaluate the role of 64-slice spiral CT with diphase dynamic scanning in predicting the T staging of gas-tric carcinoma in different locations and assessing the sensitivity of metastasis of lymph nodes.Methods 185 patients with gastric carcinoma proved by pathology underwent diphase 64-slice CT scan and performed a TNM staging according to UICC classification. The results were compared with surgical pathological findings.Results The detection sensitivity for earlier stage gastric carcinoma was 92.0% and 99.4% for the advanced stage gastric carcinoma,While the overall accuracy rates of T and N staging were 85.4%, 69.2% respectively.Compared with the pathologic findings,the accuracy rate of CT scan for T1,T2,T3,T4 staging was 72.0%, 69.6%,90.8% and 83.3% respectively.The differences were statistically significant between T1 and T3,T2 and T3.The accuracy rate of T staging was 86.0%,84.8% respectively when the lesions were located in cardia and in antrum and this difference was not statistically significant.When the lesions were located in the body of the stomach,the differences were also not statistically signifi-cant with the accuracy rate of T staging was 89.5%,86.4% ,87.2% respectively for the lateral wall of the lesser curvature,the posterior wall of the lesser curvature and both the lesser curvature and larger curvature involved.As for the N staging,The accuracy rate of N0,N1,N2,N3 was 54.3%,87.5%,68.1% and 53.6%.The differences were significant statistically between N0 and N1, N1 and N3.Conclusion There was a high accuracy in the preoperative TNM staging of the gastric carcinoma with 64-slice spiral CT. The accuracy rate of T staging of the gastric carcinoma is not relative to the lesion’s location.

Objective To evaluate the accuracy of MSCT in the pre-operative N-staging and diagnosis of metastatic lymph nodes in each group of gastric cancer.Methods Pathological and CT data of 91 patients with gastric cancer proved by surgery and pathology were analyzed retrospectively.Three-phase dynamic enhancements were performed before surgery in a unified way of hypotonic oral water,N-stage and grouping of lymph nodes of the preoperative CT imaging were evaluated by using the established diagnostic criteria and then compared with the results of surgery and pathology,the accuracy of staging and grouping was analyzed by using Kappa test.Results The accuracy of MSCT diagnosing the N-staging as a whole was 86.3%.The accuracy for N0,N1,N2 and N3 was 83.5%,89.0%,83.5% and 89.0%,respectively.The sensitivity was 86.5%,83.3%,50% and 47.4%,respectively.The specificity was 79.5%,89.4%,89.6% and 100.0%, respectively.The sensitivity for N0 was statistically different from that for N2, N0 and N3(P≤0.007).The detected accuracy for the group of left side of the cardium (No.2), periphery of the splenic hilum (No.10), posterior of the pancreastic head (No.13) were higher than other groups on MSCT with the accuracyof 100%.The sensitivity for the group of No.2,periphery of the coeliac trunk(No.9),No.10,and No.13 was 100%.The specificity for the group of No.2,No.10,and No.13 was 98.9%.Conclusion Relatively high accuracy in the preoperative N-staging and diagnosis of metastatic lymph nodes in each group of gastric cancer can be obtained by MSCT, which provide reliable information for preoperative assessment and intraoperative lymph node dissections.