title: Barium findings in retrograde intussusception.
abstract: Four instances of antiperistaltic intussusception are presented. These serve to depict the varied roentgen appearances in both types of intussusception on barium study and emphasize two simple interpretational principles: (1) when contrast material is administered orad to an antegrade or caudad to a retrograde intussusception, it must first enter the intussusceptum; and (2) when barium is administered orad to a retrograde or caudad to an antegrade intussusception, it must first enter the intussuscipiens. Attention is also directed to tube related intussusceptions and to potential difficulty in their identification.
mesh_terms: D000368:Aged; D001466:Barium Sulfate / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007443:Intussusception / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010528:Peristalsis; D011859:Radiography
chemical_list: D001466:Barium Sulfate