ARRT Cross-Sectional Anatomy 3 — Questions and Answers
Question 1: On axial CT of the abdomen, the superior mesenteric artery (SMA) is typically located:
- Directly anterior to the abdominal aorta, surrounded by fat (Correct answer)
- Posterior to the splenic vein
- Lateral to the inferior vena cava
- Within the hepatoduodenal ligament
Correct answer: Directly anterior to the abdominal aorta, surrounded by fat
The SMA arises from the anterior aorta and is typically seen as a vessel surrounded by a halo of mesenteric fat on axial CT.
Question 2: Which structure forms the posterior boundary of the adrenal glands on axial CT images?
- Diaphragmatic crura (Correct answer)
- Psoas major muscle
- Quadratus lumborum muscle
- Perirenal fat
Correct answer: Diaphragmatic crura
The diaphragmatic crura form the posterior border of the adrenal glands, which lie in the perirenal space.
Question 3: On a coronal CT reconstruction, the right hemidiaphragm is typically higher than the left because:
- The right lung is larger and displaces the diaphragm inferiorly
- The liver occupies the right upper quadrant and elevates the right hemidiaphragm (Correct answer)
- The spleen is positioned more inferiorly than the liver
- The right crus of the diaphragm is thicker than the left
Correct answer: The liver occupies the right upper quadrant and elevates the right hemidiaphragm
The mass of the liver beneath the right hemidiaphragm elevates it approximately half a rib space higher than the left.
Question 4: On axial brain CT, the internal capsule is bounded medially by which structure?
- Putamen
- Caudate nucleus (Correct answer)
- Thalamus
- Globus pallidus
Correct answer: Caudate nucleus
The anterior limb of the internal capsule is bounded medially by the head of the caudate nucleus.
Question 5: Which of the following correctly identifies the position of the common bile duct on axial CT?
- Posterior and to the left of the portal vein in the hepatoduodenal ligament
- Anterior and to the right of the portal vein in the hepatoduodenal ligament (Correct answer)
- Medial to the hepatic artery within the liver parenchyma
- Within the fissure for the ligamentum teres
Correct answer: Anterior and to the right of the portal vein in the hepatoduodenal ligament
In the hepatoduodenal ligament, the common bile duct lies anteriorly and to the right of the portal vein, with the hepatic artery to the left.
Question 6: At the level of the aortic arch on axial CT, which vessel arises first (most rightward/anterior) from the arch?
- Left common carotid artery
- Left subclavian artery
- Brachiocephalic (innominate) artery (Correct answer)
- Right subclavian artery
Correct answer: Brachiocephalic (innominate) artery
The brachiocephalic artery is the first and most rightward branch of the aortic arch, followed by the left common carotid and left subclavian.
Question 7: On axial CT of the pelvis in a female patient, the uterus is characteristically located:
- Posterior to the urinary bladder and anterior to the rectum (Correct answer)
- Anterior to the urinary bladder in the retropubic space
- Lateral to the cervix between the external iliac vessels
- Posterior to the rectum at the level of the sacrum
Correct answer: Posterior to the urinary bladder and anterior to the rectum
The uterus lies between the urinary bladder anteriorly and the rectum posteriorly in the true pelvis.
ARRT Cross-Sectional Anatomy 3
On axial CT of the abdomen, the superior mesenteric artery (SMA) is typically located: