Abdominal ultrasound

1. BASICS OF BODY
IMAGING
Dr Meron N .MD
Radiologist

2. outline
 The Hepatobiliary system
 The Gasrointestinal system/Peritonium
 The Genitourinary system
 Gynacologic and obstetrics imaging

3. The Hepatobiliary system
 Includes liver,GB and biliary ducts.
 liver is solid organ located in the right upper
abdomen
 GB is located in the GB fossa
 Biliary ducts are classified as intrahepatic and
extrahepatic.

4. Imaging modalities
 Abdominal US, CT and MRI appear as a main
imaging modality of liver
 The Vascular study is augmented with Doppler on
Ultrasound and with contrast on CT/MRI
 US and MRI are the imaging modality of Choices
for GB and biliary ducts.(MRCP)
 Role of x ray is limited in hepatobiliary imaging.

5.  Liver is seen on ultrasound as a homogeneous solid organ(size
10.5cm-15.5cm)
 Echotexture is more than the Spleen and Kidneys on US
 Portal vein/IVC and hepatic veins appear as echo free tubes
with internal Doppler flow.
 GB;Needs 8hr fasting for full distention to be better imaged
with US.
 Appears as an echofree structure,wallthickess should be <3mm
 CBD can be seen at the porta hepatis but intrahepatic biliary
ducts are not seen unless dilated.

7. Normal GB/CBD

8. Common Pathologies of Hepatobiliary system
Liver
 Various disease entities affect the liver
 The Patterns of involvement can be diffuse or focal
 Diffuse pathologies include cirrosis,fatty liver
 Focal involvement can be cystic or solid masses
 Cystic masses can be simple or complex
 Tumors,infections and various pathologies can
appear in form of solid or cystic lesions of liver.

9.  Causes of generalized increase in hepatic echogenicity include:
 diffuse fatty change
 cirrhosis: and/or coarsening
 chronic hepatitis 3: and/or coarsening
 diffuse infiltration or deposition
 malignant process
 granulomata
 tuberculosis
 Brucellosis
 sarcoidosis
 glycogen storage disease
 hemochromatosis

10.  Causes of generalized reduction of liver
echogenicity on ultrasound include:
 acute hepatitis
 diffuse malignant infiltration

11. Hepatic cirrhosis

12. Fatty Liver

13.  Cystic masses can result from simple
cysts,hydatid,abcess,hematoma or cystic tumors
 Solid masses can be benign(hemangioma,
hepatic adenoma, FNH ) or malignant
masses(HCC,Metastasis,cholangiocarcinoma, …)
 Solid masses need CT Scan(with contrast)
 Complicated cystic masses may mimic solid
masses.

14. hepatic cystic lesions

15. Hepatic solid masses

16. Biliary Pathologies.
 Common pathologies of GB are cholelithiasis,biliary
sludge and cholecystities
 Biliary sludge is thickened and concentrated bile
 It Appear on ultrasound as mobile,non-shadowing
hyperechoic lesion.
 Cholecystities is inflammation of the GB and can be
acute or chronic

17.  Ultrasound is the imaging modality of choice for
GB.
 Stones appear as a mobile echogenic foci with
strong posterior shadow.
 Acute cholecystities appear as distended GB with
thickening of GB wall ,Associated pericholyctic fluid
collection and abscess formation can be found.
 Chronic cholecystities results in small contracted GB

18. Gall stones.

20. Dilated Biliary Ducts
 Dilated ducts can be seen with US as anechoic tubes
with no Doppler flow .
 MRCP is used to see cause of obstruction
 Obstruction be due to stone
stricture,cholangiocarcinoma or Pancreatic head
tumors.

21. The pancrease/spleen
 Pancrease;Imaging modality of choice is CT Scan
 Common Pathologies are pancreatitis and
pancreatic masses(solid/Cystic).
 Pancreatitis can be acute(necrotizing/interstitial) or
chronic
 Chronic pancreatitis result is small calcified
pancrease,sometimes appers as pseudomass.
 Spleen;US and CT are imaging modalities of choice
 Size measurement is done along the splenic hilum.

23. GI SYSTEM
 includes the esophagus,stomach,small and large
intestine.
 Main imaging modalities are x ray,CT and contrast
studies,Ultrasound also has some role.
(appedix,intussusuption)
 Radiography is mainly used for suspected obstruction.
 CT is basically used for mass lesions(IBD,Tumors,TB) of
bowel.
 Contrast studies used for mucosal detail.

24.  X ray can be taken supine or erect
 Whole abdomen from the level of diaphragm to
pelvis should be included.
 Additional projection may be needed in suspected
bowel perforation.(Erect CXR;Lateral decubitus)

25. Basics of plain abdominal interpretation
 We need to see for bowel gas distribution
 If there is any caliber dilation of bowel loops
 Detect small bowel by its central location and
valvulae conniventes and large bowel by the
haustral markings
 The normal caliber of small,large bowel and
ceacum are 3,6 and 9cm respectively.
 look for the presence of air fluid
levels(length,location,number)

26.  Look for collapsed bowel segment
 Look for abnormal air
collection(Pneumoperitonium,pneumoretroperitonium,
intramural air(Pneumatosis intestinale))
 Look for abnormal calcification(renal stone,calcified
tumor,fecal shadow…) and bony structures
 Look or rectal gas shadow
 Cause of Obstruction can sometimes be evident on
x ray.

27. Normal

28. Small bowel obstruction
 Usually due to adhesion
 Enlarged caliber
 central multiple short air fluid levels,prominet valvae
convinents appearing as coiled spring are seen.
 Large bowel loops are collapsed
 Associated peumoperitonium or intramural gas can
be seen(shows advanced obstruction)

31. Large Bowel Obstruction
 Can be due to volvulus,fecal impaction,colorectal CA…
 Large bowel obstruction revels peripheral dilated
caliber of large bowel with few longer air fluid levels.
 Dilated small bowels can be seen in incompetent
ileocecal valve.
 Volvulus is seen as coffee bean appearance
 Sigmoid volvulous/ceacal volvulous differentiation is
important.
 (sigmoid are ahaustral marking,location,distal bowel is
collapsed in case of ceacal volvulus)

32.  Sigmoid volvulus
• arises in the pelvis (left lower quadrant)
• extends towards the right upper quadrant
• ahaustral in appearance
• sigmoid volvulus causes obstruction of the distal
large bowel; therefore, the ascending, transverse and
descending colon may be dilated
• few gas-fluid levels may be seen

33.  Cecal volvulus
• arises in the right lower quadrant
• extends towards the epigastrium or left upper
quadrant
• colonic haustral pattern is maintained
• distal colon is usually collapsed and the small bowel
is distended
• one gas-fluid level may be seen

35. Sigmoid vs cecal volvulus

38. 1.Pneumoperitonium ;Is abnormal peritoneal air
collection
 Best views for minimal pneumoperitonium: Erect
chest and left lateral decubitus abdomen
 Air under the diaphragm
 Also look for rigler sign
The peritoneum

39. Rigler sign

41. Pneumatosis intestinalis

42. 2.Ascities;Any irritation of peritonium results in fluid
accumulation
 Ascites can be free or loculated.
 When free tends to gravitate into dependent
areas.(Morrison's pouch,paracolic gutter,pelvic.)

44. Contrast studies
 contrast studies are important part of bowel
imaging
 We use barium swallow for esophagus
 Barium meal and follow-through for small bowel
and small intestine
 Barium enema for large bowel
 The main role is detection of small growing
polyps/masses and ulcers.

45. Barium meal/Follow Through

46. barium enema

47. CT IMAGING OF THE GIS
 Bowel wall thickening is a common finding in imaging.
CT can be helpful in the differentiation of intestinal disease.
 Important features to look for are:
 Enhancement pattern
 Length of involvement
 Degree of mural thickening
 Patency of the mesenteric vessels
 Mesenteric changes
 Lumen contents

48.  Length of bowel wall involvement
 < 5 cm involvement
 Adenocarcinoma usually presents as a short segment of bowel wall thickening. The
borders are shouldering unlike in diverticulitis, where the borders are tapering (figure).
 5-10 cm involvement
 Diverticulitis, Crohn's disease and ischemia usually present as a somewhat longer
segment of involvement.
 10-30 cm involvement
 See the list in the table. The image shows a submucosal hemorrhage. This is mostly seen
in the small bowel and duodenum.
 Diffuse involvement
 When the entire colon is involved think of ulcerative colitis.
 Involvement of both the colon and the small bowel is seen in infectious bowel disease
(IBD), edema and SLE.

50. Patterns of bowel wall
enhancement

55. 
Thank You

56. Acute appendicitis
 is an acute inflammation of the vermiform
appendix.

57. causes
• lymphoid hyperplasia, predominantly in young
patients (~60%)
• appendicolith (~33%)
• fecolith
• foreign bodies (~4%)
• Crohn disease or other rare causes, e.g. stricture,
tumor, parasite
• appendiceal tumor (usually in patients over 50 years
old)

58. ultrasound
 target (Bull's eye) sign on transverse view indicates bowel wall thickening
in the context of acute inflammation
 fluid-filled hypoechoic center
 echogenic submucosa
 hypoechoic muscularis propria
 aperistaltic, non-compressible, fluid-filled blind-ending tube
 >6 mm outer diameter (ultrasound measurements are 1-2 mm less than
CT measurements)

59.  hyperechoic appendicolith with posterior acoustic
shadowing
 identification of wall layers
 normal 5 layers imply non-necrotic (catarrhal
appendicitis)
 loss of wall stratification implies necrosis
 gas locules in appendicitis indicate gangrene

60.  periappendiceal hyperechoic indurated fat (>10
mm) surrounding a non-compressible appendix with
a diameter >6 mm
 periappendiceal complex fluid collection
 periappendiceal reactive lymphadenopathy
 wall thickening (3 mm or above)

63. Intussusception
 ​
​
vast majority of cases occur between the ages of 6 months and 3 years
 classical triad of colicky abdominal pain, vomiting and right lower
quadrant mass
 redcurrant jelly stool is a late sign, as blood and mucus in stool indicate
bowel ischemia
 ​
proximal bowel (called the intussusceptum) pulled into and pushed
through distal bowel (called the intussuscipiens) by peristalsis
 usually requires a lead point as a cause:
 typically lymphoid tissue in children (which can be hypertrophied due to
intercurrent illness)
 often a polyp or tumor in adults

64.  Ultrasound signs include:
 target sign (also known as the doughnut sign)
 pseudokidney sign
 crescent in a doughnut sign
 absent blood flow in the intussusceptum (a contraindication to enema reduction)
 free fluid within the intusussceptum
 a lead point within the intussusceptum mass eg a lymph node

65. Doughnut sign

66. Pseudokidney sign

67. ileocolic

68. Genitourinary system
 It is composed of the kidneys, urinary bladder and genital
system
 X ray,conrast study,ulltrasound and CT are the imaging
modalities of choice in GU pathologic assessment.
 X rays(KUB);The main role is detection of stone.(Kidney/ureter
stones)
 Most renal stones are radiopaque so there will be a
radiodense opacity on renal outline /UB or along the coarse
of ureters.
 Differentiation from other calcifications is
important(phleboliths.)

69. KUB

70.  US;Is good for detection of,hydronephrosis,cystic
and solid masses and diffuse renal diseases. also
for congenital renal disorders
 US Is not friendly for ureteric exam.
 Urinary bladder stone and masses are also seen
with US.
 Dynamic assessment of UB for post void residual is
also helpful

71. Normal us of the kidney

72.  Contrast studies such as IVP(intravenous pylography) and
CUG(Cystouretherography) are the main investigation
Modalities in this category.
 IVP;is administration of contrast through the IV and follow
the pattern of excretion on specific times, radigraphically.
 The main role is to look for functionality of kidneys and
look for site of obstruction
 It can also help in pattern of congenital anomaly
detection of the ureters.
 This can also be done with CT; CT urography.

74. Common pathologies of GU.
Kidneys;
 congenital(ectopic(pelvic),fused kidneys(pancake Kidneys or
crossed fused ectopic),ureter anomalies)
 Hydronephrosis;
is dilation of pelvicalyceal system
It appears as a communicating central anechoic lesion.
 Urolithiasis;
is stone formation in the urinary system
seen as echogenic foci with posterior shadow
 ureteric stones are not seen by US.

75. Pancake kidneys

76. Horseshoe kidney

77. Crossed fused renal ectopia types

78. Hydronephrosis.

79. Renal stones

80. Renal Infections
 Acute pyelonephritis
is infection of the renal pelvis and parenchyma.
 Ultrasound
• particulate matter/debris in the collecting system
• reduced areas of cortical vascularity by using power Doppler
• gas bubbles (emphysematous pyelonephritis)
• abnormal echogenicity of the renal parenchyma 1
• focal/segmental hypoechoic regions (in edema) or hyperechoic
regions (in hemorrhage)
• mass-like change
 local complications such as hydronephrosis, renal
abscess formation, renal infarction and perinephric collections.

81.  Non-contrast CT
 often the kidneys appear normal
 affected parts of the kidney may appear edematous, i.e. swollen and of
lower attenuation
 renal calculi or gas within the collecting system may be evident
 Post-contrast CT
 one or more focal wedge-like regions will appear swollen and demonstrate
reduced enhancement compared with the normal portions of the kidney
 the periphery of the cortex is also affected.
 if imaged during the excretory phase, a striated nephrogram may also be
visible 3,4
 If the kidney is imaged again within 3-6 hours, persistent enhancement of the
affected regions may be evident

83. AGN
 kidneys appear enlarged and edematous.
 parenchymal heteroechogenicity and loss of normal
corticomedullary differentiation are also noted.


84. Diffuse renal disease
 AKI
 Renal Parenchymal Disease
 CKD

85.  Renal masses;can be solid,cystic or mixed
 Renal cortical cysts are common.
 Multiple bilateral cysts suggest polycystic kidneys.
 Solid renal masses in adult can be
benign(Angiomyelolipoma,oncocytoma) or
malignant(RCC)
 Pediatrics can have wilms tumor and renal
neuroblastoma
 CT scan has a great role in detecting lesion and
characterizing extent of lesion

86. Renal cysts

88. Adrenal glands
 CT are the main imaging modality of choice.
 Pathologies include solid and cystic masses and
diffuse hyperplasia
 Cysts are usually simple cysts.

89. Urinary bladder pathologies
 Stones are common pathologies
 Acute and chronic cystitis are also seen often
 UB tumors can be benign or malignant
 Post obstructive UB changes are also seen with
thickened trabeculated wall and diverticuli
formation

93. Thank You