BE-Large Intestine (Sigmoid)
AP axial/PA axial IR Size: 14x17 LW SID: 40"" Page #'s: 2:163,258	Positioning:   • Pt supine AP, prone PA	CR Entrance & Angle:   • AP-enter MSP 2"" below ASIS; PA-enter MSP @ level of ASIS   • AP-30°-40° cephalad; PA-30°-40° caudad Collimation:   • Best to Determine:   • Rectosigmoid area of colon	Anatomy to IR:   • Eval Criteria:   • Rectosigmoid area of colon centered   • Rectosigmoid colon seen with less SI than in the AP projection   • Transverse colon & flexures may not be visualized