ARRT Cross-Sectional Anatomy 2 — Questions and Answers
Question 1: On an axial CT image at the level of the carina, which structure lies immediately posterior to the ascending aorta?
- Right pulmonary artery (Correct answer)
- Superior vena cava
- Left pulmonary artery
- Azygos vein
Correct answer: Right pulmonary artery
The right pulmonary artery passes posterior to the ascending aorta at the level of the carina.
Question 2: Which of the following best describes the CT appearance of the caudate lobe of the liver?
- Located between the gallbladder fossa and the fissure for the ligamentum teres
- Located posterior to the inferior vena cava and anterior to the portal vein
- A small segment located between the IVC and the fissure for the ligamentum venosum (Correct answer)
- The largest segment of the left hepatic lobe
Correct answer: A small segment located between the IVC and the fissure for the ligamentum venosum
The caudate lobe (segment I) lies between the IVC posteriorly and the fissure for the ligamentum venosum anteriorly.
Question 3: On axial CT of the pelvis, the obturator internus muscle is best identified by its location:
- Anterior to the pubic symphysis forming the pelvic floor
- Lining the lateral wall of the true pelvis adjacent to the obturator foramen (Correct answer)
- Posterior to the sacrum in the gluteal region
- Between the iliacus and psoas muscles in the iliac fossa
Correct answer: Lining the lateral wall of the true pelvis adjacent to the obturator foramen
The obturator internus lines the lateral wall of the true pelvis, arising from the inner surface of the obturator foramen.
Question 4: Which pancreatic landmark on CT imaging marks the junction between the head and body of the pancreas?
- The superior mesenteric vein crossing the pancreas (Correct answer)
- The common bile duct entering the pancreatic head
- The splenic artery origin from the celiac axis
- The main pancreatic duct (duct of Wirsung)
Correct answer: The superior mesenteric vein crossing the pancreas
The superior mesenteric vein crosses the anterior surface of the pancreas at the junction of the head and body.
Question 5: On axial CT at the level of L4-L5, which structure is found anterior to the vertebral body?
- Abdominal aortic bifurcation (Correct answer)
- Inferior mesenteric artery origin
- Celiac axis
- Superior mesenteric artery origin
Correct answer: Abdominal aortic bifurcation
The abdominal aorta bifurcates into the common iliac arteries at approximately the L4 vertebral level.
Question 6: On a CT image at the level of C6, which structure occupies the anterior midline of the neck?
- Trachea
- Esophagus
- Thyroid gland (Correct answer)
- Common carotid artery
Correct answer: Thyroid gland
The thyroid gland wraps anteriorly around the trachea at the C5-C6 level, occupying the anterior midline.
Question 7: On axial CT of the chest, the right and left main bronchi are best distinguished because:
- The right main bronchus is longer and more horizontal than the left
- The left main bronchus is shorter and more vertical than the right
- The right main bronchus is shorter and more vertical, making aspiration more likely (Correct answer)
- The left main bronchus has a larger caliber than the right
Correct answer: The right main bronchus is shorter and more vertical, making aspiration more likely
The right main bronchus is shorter, wider, and more vertical, which is why aspirated foreign bodies most commonly lodge on the right side.
ARRT Cross-Sectional Anatomy 2
On an axial CT image at the level of the carina, which structure lies immediately posterior to the ascending aorta?