Fig. 2

Meandering main pancreatic duct (MMPD) at the head of the pancreas. a Reverse-Z subtype C1 where the more upstream turn is tight and < 90° and the second turn is smoother and > 90°. b Reverse-Z subtype C2 where the more upstream turn is > 90° and the second turn is tight and < 90°. c Reverse-Z subtype C3 where there are two tight and < 90° turns in the horizontal direction along the same plane. d C3 subtype with the duct of Santorini which attaches to the right tight turn and drains into the minor papilla. e Loop-up configuration. f Loop-down configuration. g N-shape where the duct forms a deep notch. h N-shape where the ansa pancreatica attaches to the notch and drains into the minor papilla