normal ultrasound week 3

Superior abdominal wall

Formed by diaphragm

Posterior abdominal wall

Formed by lumbar vertebrae, lower ribs, bony pelvis, and muscles of the lower back- psoas, quadratis lumborum, and origin of transverse abdominus muscles- an aponeurosis- wide sheer of connective tissue that acts as attachment point for muscles

Anterior abdominal wall

Formed by several layers of muscle, all connected to lines alba

Linea alba

Fibrous band of connective tissue that runs down the midline of the abdomen from the xiphoid process to the symphysis pubis

Rectus abdominus “six pack”

Central muscle of the anterior abdominal wall; divided into sections by tendons

External oblique

Forms outer layer of lateral anterior abdominal wall

Arises from lower eight ribs and fans out to be inserted into the xiphoid process, lines alba, pubic crest, pubic tubercle, and anterior half of the iliac crest

Internal oblique

Forms inner layer of lateral anterior abdominal wall

Fibers run obliquely from hip up towards xiphoid process (basically at right angles to external oblique fibers)

Transversus muscle

Deepest layer of the anterior abdominal wall

Fibers run around the abdomen transversely; deep to internal oblique muscles

ultrasound of anterior abdominal wall

Most common- assess for hernia

Look for masses or trauma

Ultrasound guided nerve blocks

High frequency linear probe (superficial)

Use valsava maneuver to get hernia to move through abdominal wall

Color Doppler helps define

valsalva maneuver

Patient puts pressure on their abd. wall

Kind of like they are going to poop

Why is peritoneal cavity important?

Diseases of peritoneal organs can result in disease of the peritoneal cavity itself

• metastatic tumors

• Abscess

• As cites

• Hematoma

Why is ultrasound an excellent tool to evaluate the peritoneal cavity?

Can easily distinguish cystic from solid lesions and can evaluate the components of fluid collection

No ionizing radiation involved

Easily guide aspirations or biopsies

Peritoneum

Double layered, serous membrane (secretes fluid between layers) that lines the abdominal cavity and covers the abdominal organs

Peritoneal cavity

Space between parietal peritoneum and visceral peritoneum

Ascites

abnormal collection of fluid in space

Mesentery

Double layered fold of the peritoneal membrane that attaches part of the intestine to the posterior abdominal wall

Forms connective tissue network for blood vessels, nerves, and lymphatic vessels to run through as they supply the intestine

Omentum

Double layered fold of peritoneal membrane that attaches stomach to another organ

Greater omentum

“Fatty apron” that hangs from greater curvature of stomach between small intestine and anterior abdominal wall. Folds back on itself and attaches to transverse colon

Lesser omentum

Attaches to curvature of stomach to liver

Greater sac

Main space in peritoneal cavity

Anterior location

Lesser sac

S,Allen space in peritoneal cavity

Posterior location

“Omens bursa”

Epiploic foramen

Potential space through which portal vein, bile duct, and hepatic artery run

Small portal of communication between greater and lesser sacs of abdominal cavity

Potential space

Area within body cavity that is normally collapsed but can be a collection place for fluid, blood, or infectious material

Subphrenic spaces

Small spaces between the diaphragm and the liver, on each side of the falciform ligament

Left posterior suprahepatic space

“Superior recess of the lesser sac”

Extension of lesser sac between diaphragm and posterior superior margin of the left lobe

Sub hepatic space

Small slit like spaces within the peritoneum under the liver on each side of the porta hepatis

Morison pouch

Part of the right subhepatic space- between liver and right kidney.

“Hepatorenal space”

Common collection point for ascites

Parabolic gutters

Spaces along the ascending and descending colon which allow fluid/blood/pus/cancer cells to flow from one area of the abdomen to another

Colic compartments

Division of peritoneal cavity into superior and inferior sections by transverse colon and its mesentery

Supracolic compartment

Space superior to the transverse color

Infracolic compartment

Space inferior to the transverse colon

What is aorta ultrasound commonly used for

To assess for aortic aneurysm

Aortic ectasia

Absence of aorta diameter tapering when traveling distal

Proximal aorta diameter

~2 cm

Aorta bifurcation diameter

~1.5 cm

Common iliac arteries diameter

No more than 1 cm typically

Abnormal aorta diameter

3+ cm

Tunica intima

Inner endothelial lining of vessel

Tunica media

Smooth muscle

Middle layer of vessel

Tunica adventitia

Outer fibrous connective tissue layer

Celiac axis

1st aortic branch distal of diaphragm

Branches to form common hepatic artery and splenic artery

Superior mesenteric artery

Arteries just inferior to celiac axis

Runs parallel to aorta

Renal arteries

3rd branch off aorta

Lateral branches that arise just inferior to sma

Inferior mesenteric artery

4th branch off aorta

Rarely seen on ultrasound

Anterior branch

Common iliac arteries

Distal aorta bifurcates to form these vessels

Branch into internal and external iliacs

Most common reason for aortic ultrasound

Abdominal Aortic Aneurysm (AAA)

Risks for AAA

Over 60

Hypertension

Vascular disease

More often in men

Pulsatile abdominal mass

Predisposing factors for AAA

Arteriosclerosis- most common

Syphilis

Cystic medical necrosis

Aneurysm

Permanent localized dilation of an artery

Greater than 3 cm

AAA screening

Men age 65 to 75 who have ever smoked should be ultrasound screened once

Men age 60 or older who have a sibling or parent with an AAA should have a physical and ultrasound

No recommendation for general screening for women

Aortic Dissection

Separation of the layers of the aortic wall, with blood coursing through the “false lumen”

Aortic dissection risk factors

Hypertension

Atherosclerosis

Marian’s syndrome

Pregnancy

Chest trauma

AAA symptoms

Asymptomatic

Back pain

Pulsatile abdominal mass

Dropping hematocrit accompanied by back, abdominal, or chest pain

Aorta interview question examples

Do you have high blood pressure

Are you diabetic

Do you have a history of aortic aneurysm

Do you smoke

Have you been experiencing back, abdomen, or chest pain

IVC generally evaluated for

Thrombus or tumor invasion

Dilation of IVC can be indication of

Right ventricular heart failure

Congestive heart disease

Constrictive pericarditis

Tricuspid disease

Right heat obstructive tumors

IVC tributaries

Hepatic veins

Right adrenal vein

Right and left renal veins

Right testicular/ovarian vein

Inferior phrenic vein

4 lumbar veins

Right and left common iliac veins

Median sacral vein