inward impacted position of the tip of the transducer is maintained. By rotating the transducer in a counterclockwise manner the bile duct is followed towards the hilum into the liver and the bifurcation at the porta hepatis can be visualized. Cystic duct take‐off can also be visualized by tracing the bile duct.
Undoing the counterclockwise rotation, and rotating the scope to the right, the transducer is rotated to follow the bile duct in the intrapancreatic portion towards the papilla. With this maneuver the entire bile duct can be followed. In most of the instances the bile duct can be traced downstream all the way to the point where it joins the pancreatic duct into the ampulla. Just below the bile duct, in the intrapancreatic portion, the pancreatic duct can be visualized (Video 5.1).
Figure 5.1 Bile duct as visualized from the duodenal bulb (radial echoendoscope).
Figure 5.2 Bile duct followed towards the head of the pancreas from the duodenal bulb (radial echoendoscope). CBD, common bile duct; PD, pancreatic duct.
Figure 5.3 Gallbladder from the duodenal bulb (radial echoendoscope). CBD, common bile duct.
Figure 5.4 Bile duct and pancreatic duct from the second portion of the duodenum (radial echoendoscope). CBD, common bile duct; PD, pancreatic duct.
Figure 5.5 Common hepatic duct and cystic duct as visualized from the duodenal bulb (linear echoendoscope).
For visualizing the gallbladder the transducer is impacted in the bulb and the big wheel is turned up and the scope rotated counterclockwise so the transducer now faces the undersurface of the liver; by turning the small wheel to the right and left the gallbladder can be seen in the subhepatic region. Moving the big wheel up and down, and turning the small wheel right and left, the entire gallbladder can usually be scanned. Sometimes the scope is slightly withdrawn to visualize the entire gallbladder (Video 5.1).
Care should be taken when advancing the echoendoscope into the second portion. By slight inward push, turning the big wheel down and the small wheel to the right, the scope tip usually points in the axis of the second portion of the duodenum. Carefully moving the big wheel up and down the scope tip falls into the second portion of the duodenum. At this point the small wheel is kept turned towards the right and the scope is reduced to a short position to align the transducer along the papilla.
Figure 5.6 Bile duct and pancreatic duct from the second portion of the duodenum (linear echoendoscope).
The transducer is kept in close apposition with the major papilla. With slight right and left torque while withdrawing the scope, the bile duct is visualized as a long tubular structure closer to the duodenal wall, and deep to it lays the pancreatic duct (Figure 5.6). The bile duct can then be followed towards the liver with continued slow withdrawal of the scope and slight right and left torque. Usually the bile duct can be followed to the common hepatic duct portion when the scope tends to slip back into the stomach; to prevent this scope is again pushed inwards with counterclockwise rotation to gain a position similar to one in the duodenal bulb (Video 5.1).
Combining views from both the stations, namely the duodenal bulb and the second portion of the duodenum, the entire biliary tree can be visualized.
Chapter video clip
Video 5.1 Radial and linear array images of the bile duct from the duodenum.
6 EUS of the Normal Pancreas
Richard A. Erickson and James T. Sing Jr.
Scott and White Clinic and Hospital, and Texas A&M Health Science Center, Temple, TX, USA
Radial examination of the pancreas
In radial examination of the pancreas, the organ is usually first encountered with the instrument in the mid to upper body of the stomach. On entering the stomach, the abdominal aorta can be followed a few centimeters distally to the take‐off of the celiac artery. From there, advancing the scope just a few centimeters more distally will result in it crossing the neck/body of the pancreas (Figure 6.1). The confluence of the portal vein (PV) and splenic vein (SV) should appear deep to the pancreas neck with some minor manipulations of the orientation of the echoendoscope tip. The superior mesenteric artery can be seen in cross‐section deep to the confluence surrounded by the echogenic fat of the retroperitoneum. The portal/splenic vein confluence has been described as looking like a golf club with the portal vein being the head of the club, the splenic vein the shaft, and the superior mesenteric artery the golf ball (Figure 6.2). By continuing to follow the pancreas and splenic vessels towards the patient’s left and slightly withdrawing the echoendoscope, the tail of the pancreas is imaged (Figure 6.3). Following the splenic vessels to the left will lead to the hilum of the spleen, which is an important landmark as it marks the leftward limit of the tail of the pancreas. It is important to not forget that the tail of the pancreas may move deep from the stomach wall nestled between the left kidney and spleen (Figure 6.4). If this area is not examined carefully, pancreatic tail lesions can be easily missed. From the confluence of the portal/splenic vein, gently advancing the tip of the echoendoscope forward and angulating the tip of the echoendoscope posterior one can view the pancreatic neck (Figure 6.5). Again, if this area is not examined carefully, pancreatic neck lesions may go unnoticed.
On advancing the echoendoscope deep into the duodenum, the side‐by‐side cross‐sections of the inferior vena cava and abdominal aorta come into view. On withdrawing the echoendoscope from the deep duodenum, the most caudad portion of the ventral pancreas will usually come into view just to the patient’s left (counterclockwise) of the abdominal aorta (Figure 6.6). On gentle withdrawal, the ampulla can usually be located by identifying the first visible portions of pancreatic duct in the ventral pancreas (VP) and following the course of the duct by slow withdrawal towards the duodenal wall and ampulla (Figure