Diagnostic ultrasound ( PDFDrive )

CHAPTER 7 The Pancreas 213
and the ampullary portion of the pancreatic and bile ducts (Fig.
7.8). It is best to be explicit when describing locations within
the pancreas (e.g., mass within the tail of the pancreas) rather
than using the terms proximal and distal because these terms
are ambiguous when applied to the pancreas and may mean
diferent things to diferent people. 5
Pancreatic Tail
It is rarely necessary or helpful for the patient to drink water
before the head or body of the pancreas is scanned. he waterilled
stomach, however, may provide an excellent window for
visualizing the pancreatic tail, the most diicult portion of the
pancreas to visualize sonographically. To see the tail, place
the patient in a right anterior oblique position and scan through
the water-illed stomach (Fig. 7.9). Another helpful way to see
the region of the pancreatic tail is coronal imaging through the
spleen and let kidney, with the patient in a right lateral decubitus
position (Fig. 7.10). Color Doppler sonography can reveal the
splenic artery and vein, facilitating identiication of the tail.
Scanning through the spleen and let kidney, although not always
revealing the normal pancreatic tail itself, may show abnormalities
in the region of the tail (e.g., pseudocysts, masses) that are not
visible on other views. he view through the let kidney and
spleen should be routine in all pancreatic sonograms.
Pancreatic Parenchyma
he sonographic appearance of the normal pancreas varies widely
in parenchymal echogenicity and texture, shape, and size. he
TRANS
GDA
SMV
SMA
GB
D
IVC
FIG. 7.5 Normal Pancreatic Head and Vascular Landmarks.
Transverse sonogram shows vascular landmarks for the pancreatic head:
inferior vena cava (IVC) dorsally, superior mesenteric artery (SMA) and
superior mesenteric vein (SMV) medially, and gastroduodenal artery (GDA).
FIG. 7.7 Normal Gallbladder, Duodenum, and Pancreatic
Head. Transverse sonogram shows the gastroduodenal artery (GDA)
(arrow) as a landmark for the ventrolateral pancreatic head. The GDA
courses between the pancreas and the second portion of the duodenum
(D). The gallbladder (GB) is lateral to the duodenum. The image shows
the cephalic portion of the pancreatic head.
SMV
Unc
SMA
P
SMV
IVC
Ao
IVC
A
B
FIG. 7.6 Normal Uncinate Process. (A) Transverse sonogram showing the uncinate process (Unc), the part of the pancreatic head dorsal to
the superior mesenteric vein (SMV) and superior mesenteric artery (SMA). Note the pointed medial tip of the uncinate (small arrow) (see also Fig.
7.1B). (B) Longitudinal sonogram in another patient shows the uncinate process (arrows) dorsal to the SMV and ventral to the inferior vena cava
(IVC). The neck/body of the pancreas (P) is ventral to the SMV. Ao, Aorta; IVC, inferior vena cava.