The Abdominal Mass Flashcards
What are some indications for ultrasound examination of the abdominal walls? 4
- Palpable mass (wall vs abdominal cavity)
- Surgical wound assessment
- Trauma
- Findings on other imaging modalities
What kind of transducers do we use for abdominal scans?
High frequency linear transducer
What is the amount of pressure we need to use for abdomen wall scans?
Minimal pressure - a stand off pad may be needed
What is the patient prep for abdomen wall assessments?
No patient prep needed
What is the abdominal wall layers? 3
- Epidermis
- Subcutaneous tissue
- Muscle
How thick is the epidermis?
1-4 mm thick
What is the sonographic appearance of the epidermis? 2
- Highly reflective
- Appears echogenic
What is the subcutaneous layer consist of and how thick is it? And what does it look like sonographically? 3
- Consists of fat
- Variable thickness and echogenicity
- Typically less echogenic than muscle
The echogenicity of fat is influenced by what?
Water content
What does the anterior and lateral muscle walls consist of? 4
- Rectus abdominis
- External oblique
- Internal oblique
- Transversus Abdominis
What are the Posterior wall muscles layers? 2
- Psoas major
- Quadratus lumborum
What is the Rectus abdominis? Where is it located?
- Paired midline anterior muscles
- Extends from symphysis pubis and Punic crest to the diploid process
What is the rectus abdominis separated by?
Linea alba midline
What is the rectus abdominis enclosed by?
Rectus sheath
What is the rectus abdominis formed by?
By the aponeuroses of the internal, external and transverse abdominis
The rectus abdominis contains three tendinous insertions between what?
Xiphoid and just inferior to the umbilicus
What does the rectus abdominis attach to?
Rectus sheath anteriorly
What does the rectus abdominis do?
Localize hematomas
What is the linea alba? Where does it extend from? What does it fuse with? 3
- A fibrous band
- Extends from xiphoid to the symphysis
- Fuses with aponeuroses of the three anterolateral wall muscles
What is the linea alba wider then?
The umbilicus
What is the sonographic appearance of the linea alba?
Echogenic
What is the arcuate line?
A point between the umbilicus and symphysis where the posterior portion of rectus sheath passes in front of the rectus muscle
What is the external oblique? Where does it originate? How does it run?
- Outer layer
- Originates from outer surface of the lower 8 ribs
- Runs diagonally
What does the internal oblique lie? 2
- Deep to the external oblique
- Runs diagonally 90 degrees to external oblique
What is the transversus abdominis? Where does it lie? And how does it run?
- Innermost layer
- Lies deep to internal oblique
- Runs horizontally
What is the sonographic appearance of muscles? 3
- Hyperechoic to sonolucent
- Specular reflectors
- Striated appearance
What is the psoas muscles? Where does it originate? And where does it insert? 3
- Fan shaped muscle
- Originates in the sides of the vertebral column
- Inserts into the lesser trochanter of femur
What is the u/s appearance of the psoas muscle?
Hyperechoic/ lateral to vertebra
What is the Quadratus lumborum? Where does it originate? Where doe sit insert?
- Flat muscle which is posterolateral to psoas
- Originates in the iliac crest
- Inserts directly into the 12th rib, upper 4 lumbar vertebrae
What organ is the Quadratus lumborum posterior to?
Kidneys
What is the origin of the illacus? Where does it insert? 2
- Originates at the iliac fossa, sacrum and SI joints
- Inserts into the psoas major and lesser trochanters
What is the deep ring of the inguinal canal? Where is it located? 3
- Opening at superior end
- Located midway between ASIS and symphysis
- Anterior to femoral vessels
What is the deep ring defect in?
Transversalis fascia
What is the superficial ring? Where does it travel though?
- Opening at inferior end
- Travels through external oblique aponeurosis
What does the inguinal canal contain?
The spermatic cord in males and the round ligaments in females
What is the diaphragm? What does it separate?
- Dome shaped musculotendinous sheets
- Separates the thoracic from the abdominal cavity
What is the importance of the diaphragm?
It is a major active muscle of respiration
What is the origin of the diaphragm?
Periphery of thoracic cage
What are the three groups of muscle fibres that forms the diaphragm?
- Lumbar spine
- Lower sternum
- Lower 6 ribs
What does the lumbar spine (Curran) consist of in the diaphragm? Where does it join to form? 3
- 2 Curran (singular -crus)
- Right (broader and longer) and left
- Join in middle to form arcuate ligaments
What does the diaphragm insert into?
Central tendon
the three groups of muscle fibres converge radially and insert into a central tendon
What is the Crura? Where is it located? (Aorta and at the level of the celiac axis, what does the aorta, and IVC look like?) 4
- Thin hypoechoic band
- Superior to celiac axis- anterior to Ao
- At celiac axis - lateral to aorta
- Posterior to IVC
What are two scanning approaches to scan the pleural space?
- Abdominal approach (subcostal)
- Intercostal
What is the abdominal approach to see the pleural space? What will we see? 3
- We use a curvilinear transducer
- We will see the inferior area of pleural space
- We will see windows of the liver and spleen
What is the intercostal approach to see the pleural space? 3
- Use a linear transducer
- Use ribs as a landmark
- Pleural space within 1 cm of rib interface
What kind of rib landmarks will we see when we take the inter coastal approach? 2
- Curved hyperechoic lines
- Posterior shadowing
When we take a intercostal approach what will we see? 2
- Visceral pleura
- Parietal pleura
What does the visceral pleura look like? And how does it move? 2
- Bright linear interface
- Moves with respiration (gliding sign)
What does the parietal pleura space look like? 2
- Weak echogenic line or observed
- Hypoechoic separation of parietal and visceral pleura
What is the gliding sign?
The movement of the visceral pleura back and forth as the patient breathes during a live sonographic assessment
Label the
1. External oblique
2. Internal oblique
3. Transversus abdominis
4. Transversalis fascia
5. Parietal peritoneum
6. Subcutaneous tissue
Label the
1. Anterior layer of rectus sheath
2. Linea alba
3. Parietal Peritoneum
4. Extraperitonal fat
5. Rectus abdominis
Label the black areas
Label the black areas
Label the Quadratus lumborum and the Psoas major