Basic Radiology for Trauma

Question 1

A hemodynamically unstable trauma patient arrives in the ER. Which imaging modality should be performed FIRST?

A. CT scan of the abdomen
B. MRI of the spine
C. FAST examination
D. Plain abdominal X-ray

Answer 1

C. FAST examination

Rationale: FAST is rapid, bedside, noninvasive, and designed for unstable trauma patients to detect free fluid.

Question 2

The primary purpose of FAST in trauma is to detect:

A. Solid organ lacerations
B. Retroperitoneal bleeding
C. Free intraperitoneal or pericardial fluid
D. Bowel perforation

Answer 2

C. Free intraperitoneal or pericardial fluid

Rationale: FAST detects free fluid, assumed to be blood in trauma, not specific organ injury.

Question 3

Which of the following is NOT a standard FAST view?

A. Pericardial (subxiphoid)
B. Right upper quadrant
C. Left upper quadrant
D. Pelvic sagittal
E. Apical lung view

Answer 3

E. Apical lung view

Rationale: Lung views are part of eFAST, not standard FAST.

Question 4

The right upper quadrant FAST view evaluates fluid between which structures?

A. Liver and stomach
B. Liver and kidney
C. Kidney and spleen
D. Bladder and uterus

Answer 4

B. Liver and kidney

Rationale: The hepatorenal recess (Morison’s pouch) is the most dependent area for fluid.

Question 5

In FAST, free fluid first accumulates where in the supine patient?

A. Pelvis
B. Pericardium
C. Morison’s pouch
D. Paracolic gutters

Answer 5

C. Morison’s pouch
Rationale: Morison’s pouch is the most gravity-dependent intraperitoneal space.

Question 6

positive FAST in an unstable patient indicates the need for:

A. CT scan
B. Diagnostic peritoneal lavage
C. Immediate surgical intervention
D. Observation only

Answer 6

C. Immediate surgical intervention
Rationale: In instability, positive FAST = presumed hemorrhage → surgery.

Question 7

Which structure is evaluated in the pelvic FAST view?

A. Rectovesical pouch
B. Paravesical fat
C. Iliac vessels
D. Sacral canal

Answer 7

A. Rectovesical pouch
Rationale: FAST looks for fluid posterior to the bladder (rectovesical or rectouterine pouch).

Question 8

In females, pelvic FAST focuses on which space?

A. Vesicouterine pouch
B. Rectouterine pouch (pouch of Douglas)
C. Ovarian fossa
D. Broad ligament

Answer 8

B. Rectouterine pouch (pouch of Douglas)

Rationale: The pouch of Douglas is the most dependent pelvic space in females.

Question 9

Which trauma condition is BEST evaluated by eFAST rather than FAST?

A. Liver laceration
B. Splenic rupture
C. Pneumothorax
D. Hemoperitoneum

Answer 9

C. Pneumothorax

Rationale: eFAST adds lung views for pneumothorax and hemothorax.

Question 10

The ultrasound sign most suggestive of pneumothorax is:

A. Lung pulse
B. B-lines
C. Absence of lung sliding
D. Curtain sign

Answer 10

C. Absence of lung sliding

Rationale: Loss of lung sliding suggests air in the pleural space.

Question 11

Which ultrasound finding rules OUT pneumothorax?

A. A-lines
B. Absence of lung sliding
C. Lung point
D. Presence of lung sliding

Answer 11

D. Presence of lung sliding

Rationale: Lung sliding confirms pleural apposition, excluding pneumothorax.

Question 12

The “lung point” sign represents:

A. Pleural effusion
B. Normal lung
C. Boundary between pneumothorax and normal lung
D. Pulmonary contusion

Answer 12

C. Boundary between pneumothorax and normal lung

Rationale: Lung point is highly specific for pneumothorax.

Question 13

Which imaging is MOST sensitive for pneumothorax in trauma?

A. Supine chest X-ray
B. FAST
C. CT scan of chest
D. Rib series

Answer 13

C. CT scan of chest

Rationale: CT is the gold standard for pneumothorax detection.

Question 14

Which fracture is classically associated with aortic injury?

A. Clavicle fracture
B. First rib fracture
C. Scapular fracture
D. Sternum fracture

Answer 14

B. First rib fracture

Question 15

The best imaging for suspected blunt aortic injury is:

A. Chest X-ray
B. MRI
C. CT angiography
D. FAST

Answer 15

C. CT angiography

Rationale: CT angiography is the diagnostic modality of choice.

Question 16

Which abdominal organ injury is MOST common in blunt trauma?

A. Liver
B. Spleen
C. Kidney
D. Pancreas

Answer 16

B. Spleen

Rationale: The spleen is the most frequently injured abdominal organ.

Question 17

CT finding of contrast extravasation indicates:

A. Stable hematoma
B. Active bleeding
C. Old hemorrhage
D. Contusion only

Answer 17

B. Active bleeding

Rationale: Contrast “blush” represents active arterial bleeding.

Question 18

Retroperitoneal hemorrhage is LEAST likely detected by:

A. CT scan
B. MRI
C. FAST
D. CT angiography

Answer 18

C. FAST

Rationale: FAST poorly visualizes retroperitoneal structures.

Question 19

Which pelvic X-ray finding suggests pelvic instability?

A. Single pubic ramus fracture
B. Symphysis pubis widening >2.5 cm
C. Iliac wing fracture
D. Acetabular fracture

Answer 19

B. Symphysis pubis widening >2.5 cm

Rationale: Symphyseal diastasis indicates unstable pelvis.

Question 20

Which imaging is preferred for spinal trauma in unstable patients?

A. MRI
B. CT scan
C. Plain X-ray only
D. Bone scan

Answer 20

B. CT scan

Rationale: CT is fast, sensitive, and ideal for trauma evaluation.

Question 21

Which spinal injury is commonly missed on X-ray but seen on CT?

A. Compression fracture
B. Chance fracture
C. Transverse process fracture
D. Burst fracture

Answer 21

D. Burst fracture

Rationale: Burst fractures require CT for proper assessment.

Question 22

The “seatbelt sign” raises concern for:

A. Rib fractures
B. Hollow viscus injury
C. Lung contusion
D. Renal injury

Answer 22

B. Hollow viscus injury

Rationale: Associated with bowel and mesenteric injuries.

Question 23

Which imaging is MOST useful for detecting diaphragmatic rupture?

A. FAST
B. Chest X-ray
C. CT scan
D. Ultrasound

Answer 23

C. CT scan

Rationale: CT best visualizes diaphragmatic discontinuity.

Question 24

FAST sensitivity is LOWEST for detecting injury to the:

A. Spleen
B. Liver
C. Kidney
D. Bowel

Answer 24

D. Bowel
Rationale: FAST does not reliably detect hollow viscus injur

Question 25

A negative FAST in a stable patient should be followed by: A. Discharge B. Observation only C. CT scan D. Immediate surgery

Answer 25

Answer: C Rationale: CT is needed to rule out occult injuries.

Question 26

Which CT phase best identifies solid organ injury? A. Non-contrast B. Arterial phase C. Portal venous phase D. Delayed phase

Answer 26

C. Portal venous phase Rationale: Portal venous phase optimally shows organ parenchyma.

Question 27

Renal trauma grading is BEST assessed by: A. Ultrasound B. IVP C. CT scan with contrast D. Plain X-ray

Answer 27

C. CT scan with contrast Rationale: CT accurately grades renal injury.

Question 28

Which finding suggests tension pneumothorax? A. Rib fracture B. Tracheal deviation C. Blunted costophrenic angle D. Pulmonary contusion

Answer 28

B. Tracheal deviation Rationale: Mediastinal shift indicates pressure effect.

Question 29

Which imaging is contraindicated in unstable trauma patients? A. FAST B. Portable X-ray C. CT scan D. Ultrasound

Answer 29

C. CT scan Rationale: CT requires patient transport and stability.

Question 30

In trauma, contrast CT is avoided primarily in patients with: A. Head injury B. Hypotension C. Renal failure D. Rib fractures

Answer 30

C. Renal failure Rationale: Contrast may worsen renal dysfunction.

Question 31

The main goal of trauma radiology is to: A. Provide definitive diagnosis B. Replace physical exam C. Rapidly identify life-threatening injuries D. Avoid surgery

Answer 31

C. Rapidly identify life-threatening injuries

Question 31

A 27-year-old male is brought to the ER after a high-speed motorcycle crash. He is hypotensive and tachycardic. FAST shows free fluid in the right upper quadrant and pelvis. What is the MOST appropriate next step? A. CT scan of the abdomen with contrast B. Diagnostic peritoneal lavage C. Immediate exploratory laparotomy D. Repeat FAST after fluid resuscitation

Answer 31

C. Immediate exploratory laparotomy Rationale: In a hemodynamically unstable patient, a positive FAST indicates ongoing intra-abdominal bleeding requiring immediate surgery, not CT.

Question 32

A trauma patient has sudden respiratory distress after intubation. eFAST shows absent lung sliding on the right with a visible lung point. What is the MOST likely diagnosis? A. Pulmonary contusion B. Hemothorax C. Right pneumothorax D. Atelectasis

Answer 32

C. Right pneumothorax Rationale: Absent lung sliding with a lung point on eFAST is highly specific for pneumothorax.

Question 33

A 35-year-old female involved in a vehicular collision is hemodynamically stable. FAST is negative, but she continues to complain of worsening abdominal pain. What is the BEST next imaging step? A. Repeat FAST B. CT scan of the abdomen and pelvis with contrast C. Plain abdominal X-ray D. Diagnostic laparotomy

Answer 33

B. CT scan of the abdomen and pelvis with contrast Rationale: A negative FAST does not rule out injury. In stable patients with persistent symptoms, contrast-enhanced CT is indicated.

Question 34

A trauma patient has blunt chest injury. Chest X-ray shows a normal mediastinum, but clinical suspicion for aortic injury remains high. What is the BEST next step? A. Repeat chest X-ray in 6 hours B. FAST examination C. CT angiography of the chest D. Transesophageal echocardiography

Answer 34

C. CT angiography of the chest Rationale: Normal CXR does not exclude aortic injury. CT angiography is the diagnostic test of choice when suspicion remains high

Question 35

A 42-year-old male presents after a fall from height. CT scan shows free intraperitoneal fluid with no identifiable solid organ injury. What injury should be MOST suspected? A. Liver laceration B. Splenic rupture C. Hollow viscus injury D. Renal contusion

Answer 35

C. Hollow viscus injury Rationale: Free fluid without solid organ injury on CT strongly suggests bowel or mesenteric injury, a classic USMLE concept.

Question 36

Which of the following findings on eFAST MOST strongly indicates tension pneumothorax? A. Absence of lung sliding B. Presence of lung point C. Mediastinal shift with hemodynamic instability D. A-lines on ultrasound

Answer 36

C. Mediastinal shift with hemodynamic instability Rationale: Tension pneumothorax is a clinical diagnosis. Imaging findings plus hemodynamic compromise indicate tension physiology requiring immediate decompression.

Question 37

trauma patient with pelvic fracture is hypotensive despite fluid resuscitation. FAST is negative. What is the MOST likely source of bleeding? A. Intraperitoneal hemorrhage B. Retroperitoneal bleeding C. Splenic laceration D. Bowel perforation

Answer 37

B. Retroperitoneal bleeding Rationale: Pelvic fractures commonly cause retroperitoneal hemorrhage, which is not detected by FAST.

Question 38

Which imaging finding is MOST specific for active arterial bleeding in trauma? A. Perihepatic fluid B. Hematoma C. Contrast extravasation on CT D. Organ enlargement

Answer 38

C. Contrast extravasation on CT Rationale: Contrast “blush” on CT represents active arterial bleeding and often necessitates embolization or surgery.

Question 39

A 30-year-old male involved in a high-speed MVC is hypotensive. FAST is negative on initial assessment. Despite fluid resuscitation, blood pressure remains low. What is the MOST appropriate next step? A. Repeat FAST after 30 minutes B. CT scan of the abdomen and pelvis C. Diagnostic peritoneal lavage D. Observation in the ICU

Answer 39

C. Diagnostic peritoneal lavage Rationale: In an unstable patient with a negative FAST, diagnostic peritoneal lavage (DPL) is indicated to detect occult intraperitoneal bleeding that FAST may miss.