Examkin

Question

Difficulty: HardOrdering Imaging Studies

A 34-year-old male is brought to the emergency department after a high-speed motorcycle collision. On arrival, his blood pressure is 112/70 mm Hg and heart rate is 108/min. Primary survey reveals a patent airway, bilateral breath sounds, and normal heart sounds. The patient complains of severe lower abdominal and pelvic pain. Examination reveals ecchymosis over the suprapubic and perineal regions. A single drop of blood is noted at the urethral meatus. The prostate cannot be reliably palpated due to severe patient discomfort, and the pelvis is mechanically unstable to gentle compression. Arrange the following imaging modalities in the most appropriate chronological sequence for this patient's diagnostic workup.

  1. 1Focused Assessment with Sonography for Trauma (FAST) examination
  2. 2Retrograde urethrography
  3. 3Computed tomography (CT) of the abdomen and pelvis with intravenous contrast
  4. 4Computed tomography (CT) cystography

Answer

The correct sequence is: 1) Focused Assessment with Sonography for Trauma (FAST) examination, 2) Retrograde urethrography, 3) Computed tomography (CT) of the abdomen and pelvis with intravenous contrast, 4) Computed tomography (CT) cystography.
In blunt abdominal and pelvic trauma, imaging must be staged to prioritize immediate life-threats, prevent iatrogenic injury, and systematically evaluate the urinary tract. The sequence begins with a bedside FAST exam during the primary survey to evaluate for catastrophic bleeding. Next, due to the presence of blood at the urethral meatus (a cardinal sign of urethral injury), retrograde urethrography is mandatory before a Foley catheter can be placed. Once the urethra is cleared and a catheter is inserted, the stable patient undergoes a standard CT of the abdomen and pelvis with IV contrast to assess solid organs and the pelvic fracture. Finally, because standard IV contrast does not adequately distend the bladder, a dedicated CT cystogram is performed by retrogradely instilling contrast through the Foley catheter to rule out bladder rupture.

Step-by-Step Solution

1
Identify life-threatening hemorrhage risk
Perform a FAST examination.
The patient has suffered high-energy blunt trauma. Before transferring a patient out of the resuscitation bay or addressing specific localized injuries, gross intra-abdominal hemorrhage must be ruled out.
2
Evaluate the contraindication to urethral catheterization
Perform retrograde urethrography (RUG).
The patient exhibits a mechanically unstable pelvis and blood at the urethral meatus, highly suspicious for a urethral injury. A RUG must confirm an intact urethra before a Foley catheter can be placed.
3
Assess solid organs and pelvic bone architecture
Perform CT of the abdomen and pelvis with IV contrast.
With the patient hemodynamically stable and a catheter safely placed, a standard contrast-enhanced CT is necessary to evaluate the extent of intra-abdominal solid organ injury and pelvic ring disruption.
4
Definitively rule out bladder rupture
Perform CT cystography.
Standard IV contrast CT does not adequately distend the bladder to reliably detect tears. A dedicated CT cystogram, filling the bladder retrogradely with contrast, is the final required imaging step for the lower genitourinary tract.

Key Concept

Staged imaging in blunt pelvic trauma prioritizes ruling out immediate life-threats (FAST), preventing iatrogenic harm from catheterization (Retrograde Urethrography), and methodically assessing structural (CT Abdomen/Pelvis) and lower urinary tract injuries (CT Cystography).
Rate this question

Topics

Ordering Imaging Studies

More questions from this topic