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.

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 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.