Objective To study the best projection position of cervical articular facet.Methods The cervical facet angle(FA) which was the joint angle between sagittal plane of body and the continual line of cervical facet was measured on cervical CT images in 63 healthy people.Results The FA was 70?~75?,during projection,the coronal plane of body in the form of 70?~75? to the film,this projection position was called cervical facet position.Conclusion Cervical facets and its interspace of joint can be showed clearly in the cervical facet position of projection.

Objective To explore CT features of ectopic pancreas in the gastrointestinal tract,and to compare and analyze with the pathological findings.Methods The clinical data of 20 cases with ectopic pancreas in gastrointestinal tract proved by surgery pathology or endoscopic biopsy were analyzed retrospectively,and the characteristics were summarized.Results Ectopic pancreas in gastrointestinal tract-20 single lesions,4 cases at lesser curvature of gastric body,7 cases at greater curvature of gastric antrum,6 cases at lesser curvature of gastric antrum,1 case at gastric angle and 2 cases at duodenum.The longest diameter of ectopic pancreas was from 0.8 to 3.5 cm,while the shortest one was from 0.6 to 2.5 cm.The axis of the lesions was parallel to the wall of the gastrointestinal tract. For 1 8 ectopic pancreas in gastrointestinal tract,1 6 were ovoid or round in shape,and the other 2 were slight lobulated.2 lesions in duodenum were ovoid in shape.1 2 lesions'margins were well-defined and ill-defined in other 8.Plain CT showed the ectopic pancreas with homogeneous density,1 8 lesions with endoluminal growth and exophytic growth of other 2 cases.The cystic change was also found in 2 cases.Enhanced CT showed 2 lesions with significant homogeneous enhancement,mainly composed of pancreatic acini in pathology;14 with medium enhancement close to the normal pancreas,composed by pancreatic acini,islet and ducts,and 2 with slight enhancement,composed with mature differentiated mucous glands with ducts.Two lesions'center cystic change areas show no enhancement result.Conclusion The CT features,such as direction of its organic axis,endoluminal growth and enhancement patterns have its useful characteristics.Different enhanced patterns of ectopic pancreas in gastrointestinal tract are related with the pathologic change.