A 68-year-old man presents to the outpatient clinic with a 4-week history of progressively worsening yellowing of his skin and eyes, generalized pruritus, and a 15-lb (6.8 kg) unintentional weight loss. He reports that his urine has become dark brown and his stools are pale and malodorous. He has no significant past medical history and takes no medications. Vital signs are within normal limits. Physical examination reveals marked scleral icterus and jaundice. Abdominal examination is notable for a palpable, non-tender, rounded mass in the right upper quadrant.
Laboratory studies show:
Total bilirubin: 14.2 mg/dL
Direct bilirubin: 11.5 mg/dL
Alkaline phosphatase: 520 U/L
Aspartate aminotransferase (AST): 85 U/L
Alanine aminotransferase (ALT): 92 U/L
Lipase: 45 U/L
A transabdominal right upper quadrant ultrasound is performed, revealing a significantly dilated common bile duct measuring 16 mm, intrahepatic biliary ductal dilation, and a markedly distended gallbladder without evidence of gallstones. A vague, hypoechoic region is noted near the head of the pancreas.
Which of the following is the most appropriate next step in the diagnostic imaging evaluation of this patient?
- Multiphasic contrast-enhanced computed tomography of the abdomenCevap
- BEndoscopic retrograde cholangiopancreatography
- CEndoscopic ultrasound with fine-needle aspiration
- DMagnetic resonance cholangiopancreatography without intravenous contrast
- EPositron emission tomography-computed tomography