Abdominal Sonography: Sonographic features and normals values

what are the 3 primary wall layers for vessels?

1. tunica Intima (innermost)

2. Tunica Media (middle)

3. Tunica Adventitia (outermost)

which vessel wall layer has thin epithelial cells?

Tunica intima

which vessel wall has a muscular layer?

Tunica Media

which vessel wall is used as a protective layer?

Tunica Adventitia

Why are vessels easier to compress?

Because arteries have thicker vessel walls than veins

What are some similarities that veins and arteries have?

Both have 3 layers of walls

Both carry blood

What are some differences with veins and arteries? (5)

1. Artery walls are thicker/ more muscular

2. Venous walls are thinner and more pliable. compressible

3. Veins can have valves

4. Arteries pulsate while veins collapse with breathing/ respiratory

5. Arteries take blood from heart to the body while veins take blood from the body to the heart

How many segments does the aorta have and what are they?

5 segments;

1. ascending

2. arch

3. descending

4. thoracic

5. abdominal

TRUE OR FALSE:

The abdominal aorta lies in the retroperitoneum and tapers in size as it gets more distal

true

what are the branches off of the abdominal aorta?

celiac trunk, superior mesenteric artery, renal arteries, inferior mesenteric artery, common iliac arteries

what are the branches coming off of celiac trunk/axis?

1. Hepatic artery

2. Left gastric Artery

3. Splenic

Hepatic Artery

supplies blood to the liver;

travels superior to pancreatic head then turns right and meets PV

Gastroduodenal artery (GDA) branches off of hepatic

What are the variations of Hepatic Artery? 3 different types

Type 1: "normal" branching pattern in which the hepatic Artery branches off of the Celiac trunk

Type 2: Replaced Left Hepatic artery; The LHA branches off the Left gastric Artery

Type 3: Replaced Right Hepatic artery; RHA branches off the SMA, while the LHA branches off of the celiac trunk

left gastric artery

supplies blood to stomach and esophagus

branches anteriorly and superiorly in a leftward direction.

What are some variations that left gastric artery

can arise from hepatic artery or splenic artery

Splenic artery

supplies spleen, stomach, and pancreas

branches laterally toward the left and runs posterior and superior to pancreatic body and tail.

Superior Mesenteric Artery (with variant)

supplies blood to the small and large intestine; blood flow changes depending on fasting

Can share a trunk with celiac

Renal Arteies

Supplies blood to kidneys, ureter and adrenal glands

inferior to SMA, The right renal artery originates postero-lateral and runs posterior to the IVC before reaching the kidney. The left renal artery originates laterally and runs directly toward the kidney.

Inferior mesenteric artery

Supplies the descending large intestine, sigmoid colon, and rectum

Common iliac arteries

supplies pelvis and lower limbs

Arteries have branches while veins have

tributaries

Inferior Vena Cava (IVC)

Delivers blood from lower extremities, pelvis and abdomen to the right atrium; lies right of the aorta

azygos and hemiazygos veins

lie on either side of the thoracic vertebral bodies and return blood from the chest wall and drain into the superior vena cava

Only see these if they are dialated

Tributaries of IVC

common iliac veins, lumbar veins, right gonadal vein, right renal vein, right suprarenal vein, inferior phrenic vein, hepatic veins

Which renal artery is longer and why?

Right renal artery is longer because the Aorta and abdominal aorta are left side structures; meaning that it would have to pass behind IVC to reach the right kidney

Which renal vein is longer and why?

Left renal vein is longer because the inferior vena cava is on the right side

LRV runs ________ to aorta and ________ to SMA

anterior; posterior

Renal veins

Drains the kidneys. Empties directly into the inferior vena cava.

hepatic veins

drain blood from the liver to return to the heart;

LHV: drains left lobe

RHV: right lobe

MHV: caudate lobe

Portal tributaries

Portal vein, SMV,splenic vein, IMV, cystic vein, gastric vein, pancreaticoduodenal, and paraumbilical vein

Portal vein is special because:

its taking blood to the liver rather than draining to return to the heart

porta hepatis

where the blood and lymph vessels, bile ducts, and nerves enter and leave the liver

portal confluence

where the SMV and splenic vein come together to make the main portal vein

Why do we do an aorta sonogram?

Hypertension, History of aneurysms, masses on aorta

why do we have an IVC sonogram?

Hydration/volume status, heart failure, concern for thrombus, guidance and placement of clot catching device

Normal AP and Width measurements of the aorta

Proximal Aorta = 2.5 cm

Distal Aorta = 1.5 cm

What is the nutcracker phenomenon?

a variant of the SMA; occurs when the left renal vein is significantly compressed between the aorta and SMA

what is the biliary system composed of directly and indirectly?

Directly: gallbladder and bile ducts

Indirectly: liver and GI system

What is cholecystokinin? (CCK)

CCK is a hormone that triggers the gallbladder to contract to release bile into ducts; response to the presence of chyme.

the gallbladder is ______, which means it is outside of the liver

extrahepatic

what is the location of the gallbladder

within the main lobar fissure BTW right and left lobes of the liver

what are the components of the GB

1. Fundus: Widest portion; May project from inferior edge of liver

2. Body: Main part, In contact with liver

3. Neck: Narrowest area; Narrows to become Cystic duct which connects GB to common hepatic duct

Spiral valves of Heister (supportive, not functional

function of the gallbladder?

Stores, concentrates and releases bile into the GI system to emulsify fat/lipids

what are the layers of the gallbladder made out of?

inner layer = epithelial mucosa

middle layers = muscular and subserous

outer layer = serosa adventitia

The common bile duct is made up of

common hepatic and cystic duct

Portal triad

portal vein, hepatic artery, bile duct

biliary tree

intrahepatic ducts

Can we live without a gallbladder, why or why not?

we can live without one because the ducts can take over and store bile

What are the anatomical relationships of the gallbladder?

GB is lateral to

GB is anterior to

Lateral: 2nd part of duodenum

Anterior: Right Kidney and Transverse colon

biliary system function

concentrates and stores bile (GB, CBD, after cholecystectomy)

What are the components of bile? (6)

1. Bilirubin (main one)

2. Cholesterol

3. Bile Salts

4. phospholipids

5. water

6. electrolytes

what is the function of bile?

helps to break down/ emulsify lipids/ fats into smaller pieces so thats they can be absorbed bot the digestive tract

what is bilirubin?

pigment in bile

when RBC' break down, they are taken from the bloodstream by the liver and processed into:

Bilirubin

Direct bilirubin

Conjugated with glucuronic acid, water soluble

Indirect bilirubin

Unconjugated, water insoluble

In the GI tract, the bilirubin within the bile is acted on by bacteria that convert it to

urobilinogen

Back-up of bilirubin will cause

Jaundice because extra bilirubin will get into the bloodstream;\

What is the shape of the gallbladder

pear-shaped

what is the AP/Width at Mid normal measurements of GB

< 4 cm

Anterior wall thickness at mid normal

< 3mm

Gallbladder wall measurement with ascites

< 4 mm

Intrahepatic ducts diameter

< 2mm

What is a phrygian cap

folding of the fundus of the gallbladder

What is Hartmann's pouch?

an outpouching of the gallbladder neck

what is.a gallbladder duplication

when there is an extra GB

Why physicians order gallbladder sonograms

1. Congenital anomalies that are seen prenatally

2. Epigastric pain

3, RUQ pain

4. Jaundice

5. Nausea and vomiting

6. Abnormal lab values

7. abnormal findings on other imaging studies

Length of the Gallbladder

10-13 cm

Capacity of the gallbladder

30-50 ml

Cystic ducts measures _____ length

2-4 cm

Bile duct width measurements

Normal: 4-6 mm

Why would a doctor order a liver sonogram (6)

If the patient had the following symptoms:

1. RUQ pain

2. Elevated liver enzymes (LFTs)

3. Jaundice

4. Follow-up on known liver abnormalities

5. screening for those with hepatic disease

6. evaluating abnormalities noted on other imaging studies

In embryology, what is developed in the 4th week RUQ

Liver, gallbladder, bile ducts

In embryology, what is developed in the 5th week RUQ

Differentiation: Cystic duct, gallbladder, Right and Left hepatic lobes, Bile duct system

In embryology, what is developed in the 6th week RUQ

right and left hepatic lobes are formed

In embryology, what is developed in the 6th + week RUQ

Hemopoiesis; formation of cellular components of blood

Bile: liver involvement indigestion after birth

Umbilical vein left branch is what after birth

Ligamentum teres

Umbilical vein right branch is what after birth

Ligamentum venosum

What is the 3 main cell types for the liver

1. Hepatocytes: male up the liver parenchyma, are useful for metabolism

2. Biliary Epithelial Cells: For bile creation

3. Kupffer cells: phagocytic cells that eat up debris

Damage to the cells in the liver can cause

alter liver enzymes

What are the major functions of the liver? (8)

1. Bile formation and secretion

2. Metabolism of carbohydrates, fats, proteins

3. Immunity and phagocytosis

4. Storage for vitamins, glucose, iron, fats, amino acids/protein

5. Blood resivor

6. heat production

7. Detoxification and metabolism of drugs and hormones

8. Lymph formation

what are the basic functional unit of the liver

hepatic lobules

What is the liver lobules composed of?

Hepatocytes

kupffer cells

centra; vein

sinusoids

portal triad

liver parenchyma is known as

the meat of the liver

What is Reidel's lobe?

a normal variant of the liver where the right lobe extends far below right kidney

Situs inversus

complete reversal of all abdominal organs

what is the largest organ in the abdomen?

LIver; ·

13-15 cm length midclavicular

17 cm intercostally

1400-1600 grams

AP: 10-12.5 cm

Transverse/width 20-22.5cm

in the liver, what is filled with blood

sinusoids

What are the main 2 vessels used for blood supply to the liver

Portal vein and Hepatic artery

ligamentum teres

appears as bright echogenic foci on transverse image; along with falciform ligament, it divides medial and lateral segments of the left lobe of the liver

ligamentum venosum

separates the left lateral lobe from the caudate lobe; seen better in sagittal

Main lobar fissure

divides the right and left lobes of the liver; seen in the sagittal plane as an echogenic line between the gallbladder neck and the main portal vein

falciform ligament of liver

a ligament that separates the left and right lobes and connects the liver to the diaphragm

Right hepatic artery separates

right anterior and right posterior segments

Middle hepatic artery separates

Right and left lobe

Segment I:

Caudate lobe

Segment II:

Left lateral superior segment

Segment III:

Left lateral inferior segment

Segment IV:

Left medial segment

Segment V:

Anterior inferior segment