2. A normal Gallbladder should be thin walled (<3mm) and
anechoic.It is a pear shaped secular structure for bile storage in
the Right Upper Quadrant. Its size varies depending on the
amount of bile. Fasted it will be approximately 10cm long.
3.
4. Patient position
Generally the gallbladder is best viewed in the left
lateral decubitus position. However it can be viewed
with the patient supine and erect.
Erect views may be useful to determine if stones are
mobile or impacted in the neck.
5. Patient Preparation
Fast for 6 hours. No food or drink.
Preferably book the appointment in the morning
to reduce bowel gas.
6. TECHNIQUE
Patients should fast 8 hours after midnight before
gallbladder sonogram
Fasting ensure adequate gallbladder distention and
reduce upper abdominal bowel gas.
Most gallbladder examinations start with the patient in
the supine position
Using a 3- to 5-MHz sector/curved transducer
The gallbladder should be scanned from both sub
costal and intercostal approaches whenever possible
7. When scanning from a sub costal view, a deep inspiration
will usually allow better visualization.
Scanning from a more lateral and superior approach (an
intercostal space) using more of the liver as a window.
Scans should routinely be obtained with the patient in a
variety of positions (left posterior oblique, left lateral
decubitus, prone, upright)
8. The prone position is most useful in patients in whom the
gallbladder is in a horizontal orientation with the fundus
located Anteriorly.
Stones that fall into the fundus when the patient is prone
can be seen falling back into the neck as the patient rolls
from a prone to a supine position.
9. The upright view is most useful in patients in whom the
gallbladder is in a vertical orientation with the fundus
located inferiorly.
Upright views can be obtained in the sitting position,
although it is usually easier to scan with the patient
standing.
10. Gallstones
The most common
symptom of gallstones is
acute right upper quadrant
(RUQ) or epigastric pain
lasting for up to 6 hours
and ending when the
stone disimpacts from the
gallbladder neck.
Appearence
Gallstones appear as
mobile, echogenic,
intraluminal structures that
cast acoustic shadows.
Demonstration of
shadowing is important.
Symptoms
11. A ,Typical small stone with distinct clean acoustic
shadow.
B, Large Stone
C, Multiple small stones
12. Wall–echo–shadow complex (WES) is a reliable sign
of a stone-filled gallbladder
Fig.
The complex varies from a very distinct series of
arcshaped lines.
13. Floating stones
When the density of bile is unusually high, stones may float.
It indicates that the floating stones are cholesterol in nature.
14. Faceted stones.
Gallstones are generally either round or ovoid. Faceted
stones are also fairly common it looks like a turtle back
and has flattened sides.
Fig.
A. A single large stone with angular margins.
B. Multiple smaller stones with angular margins.
15. POLYPS
Cholesterol polyps are by far the most common type of
gallbladder polyp.
They are usually 5 mm or less in size and only rarely get
bigger than 10 mm.
16. Gallbladder (GB) polyps in different patients.
Fig.
A. Longitudinal upright view shows a small (<5 mm) no shadowing
polypoid defect along the nondependent portion of the GB typical of a
cholesterol polyp.
B. Longitudinal view shows multiple small polyps.
17. Adenomyomatosis
It is characterized by mucosal hyperplasia and
thickening of the muscular layer of the gallbladder.
It is unrelated to gallstones. The three most common
forms of adenomyomatosis are shown in fig.
18. Adenomyomatosis with severe wall thickening.
Fig.
A. Transverse view shows severe wall thickening.
B. Longitudinal view shows a comet-tail artifact (arrow).
C. Color Doppler view shows twinkle artifact in several areas
(arrowheads)