Objective To compare the safety of laparoscopic pancreatoduodenectomy(LPD)and open pancreatoduodenectomy(OPD)and analyze the learning curve and safety at different stages of LPD.Methods A retrospective analysis was conducted on the clinical data of 50 LPD patients and 54 OPD patients in the Department of Hepatopancreatobiliary Surgery of Suzhou Hospital Affiliated to Nanjing Medical University from January 2020 to June 2024,and intraoperative and postoperative conditions were compared.The Cumulative Sum(CUSUM)analysis method was used to analyze the technical nodes of the LPD learning curve.Results There were no significant differences in operation time and intraoperative blood loss between the LPD group and the OPD group(P＞0.05).There was also no significant difference in the incidence rates of pancreatic fistula(grade B and C),delayed gastric emptying,postoperative bleeding,biliary fistula and intra-abdominal infection between the LPD group and the OPD group(P＞0.05).A time series plot of operation time was drawn based on the patient's operation time and surgical sequence,yielding a fitted curve.Curve analysis showed initial stage and stable stage were finished at the 17th and 24th cases.The LPD learning curve could be divided into three stages:stage Ⅰ characterized as the initial stage(cases 1 to 17),stage Ⅱ characterized as the stable stage(cases 18 to 24),and stage Ⅲ characterized as the proficient stage(cases 25 to 50).The operation time in stages Ⅱ and Ⅲ was significantly shorter than that in stage Ⅰ,and the intraoperative blood loss in stage Ⅰ was significantly higher than that in stage Ⅲ(P＜0.05).There was no significant difference in the incidence of complications among the three stages(P＞0.05).Conclusion LPD and OPD show no significant differences in indications and safety.The LPD learning curve can be divided into three stages.As the number of surgeries completed increa-ses,the operation time of physicians gradually shortens,and the incidence of complications of patients gradually decreases.

Objective To summarize CT and MRI features of hyaline vascular type localized Castleman disease(LCD)and analyze the causes of misdiagnosis,to improve the preoperative diagnosis rate.Methods The clinical and imaging data of 7 patients with hyaline vascular type LCD confirmed by operation and pathology were analyzed retrospectively.Results (1)6 cases were misdiagnosed before operation,1 case was misdiagnosed as pancreatic neuroendocrine tumor,1 case as thymoma,1 case as neurogenic tumor,1 case as pheochromocytoma, 1 case as clear cell renal cell carcinoma and 1 case as small mesenteric stromal tumor.(2)1 case was located in the right neck,1 case in the anterior superior mediastinum,1 case in the neck of the pancreas,1 case in the upper part of the left kidney,2 cases in the retroperitoneum and 1 case in the lower abdomen.(3)3 cases were scaned by dynamic enhanced MRI,3 cases were scaned by dynamic enhanced CT, and 1 case was checked by plain CT and enhanced MRI.CT and MRI showed that 7 cases had a round or elliptical soft tissue mass, and 4 cases with well defined margin,3 cases were not clear in edge,2 cases with spot or strip calcification on CT images,4 cases had slightly longer T1 and longer T2 signal,4 cases were restricted of diffusion and had higher signal on DWI.All the lesions were enhanced in arterial phase,and went on in the delayed phase.There were 5 cases with distorted vascular shadow in the middle and/or around of the mass, 3 cases with strips,spoke-like low-density areas or low-signal areas,and some lesions were filled in delayed phase.Conclusion CT and MRI features of hyaline vascular type LCD have certain characteristics such as rich blood supply,enhancement in persistent,tortuosity of peripheral vascular,with some short strip calcification and high signal on DWI,which may be helpful for preoperative diagnosis.

Objective To evaluate the diagnostic value of six-slice coronal reformations in patients with acute midepigastric pain. Methods A total of 974 patients with acute midepigastric pain were included in this study and divided into group A(coronal reformation)and group B(non-coronal reformation).For group A,reconstructed coronal and oblique-coronal images were acquired.A comprehensive diagnosis was made based on coronal reformations and axial planes.Anatomical nomenclature was adopted,including kidney-ureter plane,abdominal aorta plane,superior mesenteric artery plane,ascending colon-appendix plane,stomach-cholecyst plane and colon-small intestine plane.For group B,the diagnosis was made based on axial planes.Finally,a comprehensive analysis was made,missed cases in these two groups were counted and compared,and statistical analysis was performed using the SPSS software(version SPSS V17).Results For group A,the missed diagnosis was made in 12 cases(1.23%)and it was 53 cases(6.58%)for group B.There was a statistically significant difference between two groups(P<0.05).Conclusion Combined with axial planes or oblique coronal reformations,six-sclice coronal reformation can reduce the the rate of missed diagnosis of acute midepigastric pain.

Objective To establish an accuracy test method for MDCT dose assessment based on information in DICOM images.Methods The type of MDCT studied in this paper was widely used in clinical practice.A software package developed by java language was used to automatically read doserelated information from DICOM files of MDCT.The CTDIvol and DLP of each pectoral or abdominal scan was calculated based on these information and the basic scan parameters such as collimation,mAs and pitch.The calculated values were compared with the displayed values.Results For pectoral scans,the difference between the calculated and displayed values was between-2％-8％ for CTDIvol,and-2％-5％ for DLP.For abdominal scan,the difference between the calculated and displayed values was 0-2％ for CTDIvol,and-2％-3％ for DLP.Conclusions This method is useful for MDCT dose assessment and is worth disseminating its application for general use.