What is the recommended imaging for left upper quadrant (LUQ) pain?

Recommended Imaging for Left Upper Quadrant Pain

For patients presenting with left upper quadrant (LUQ) pain, CT of the abdomen and pelvis with contrast media is the recommended first-line imaging modality due to its high diagnostic accuracy and ability to detect a wide range of pathologies. 1, 2

Initial Imaging Approach

• CT abdomen and pelvis with contrast media is the most appropriate initial imaging study for LUQ pain with excellent specificity (100%) and moderate sensitivity (69%) 2
• CT can accurately identify multiple potential causes of LUQ pain including splenic, pancreatic, gastric, and renal pathologies 3
• CT provides superior diagnostic yield compared to plain radiography for detecting sources of abdominal pain 1
• CT results can change the leading diagnosis in up to 51% of patients and management decisions in 25% of patients with abdominal pain 1

Specific Clinical Scenarios

When to Consider Ultrasound First:

• For suspected gallbladder pathology that may refer to LUQ (ultrasound has 81% sensitivity and 83% specificity for acute cholecystitis) 1
• In pregnant patients or young patients where radiation exposure is a concern 1
• For premenopausal women when gynecologic pathology is suspected 1

When to Consider Unenhanced CT:

• When IV contrast is contraindicated 1
• For suspected urolithiasis (sensitivity and specificity near 100%) 1
• In elderly patients (≥75 years), where unenhanced CT has similar accuracy to contrast-enhanced CT for acute abdominal pain 1

Common Pathologies Causing LUQ Pain

• Splenic disorders (infarction, abscess, rupture, or torsion) are best evaluated with contrast-enhanced CT 4, 3
• Acute pancreatitis typically requires CT for severity assessment and detection of complications 1, 5
• Gastric pathology including gastritis and peptic ulcer disease 3
• Renal pathology including pyelonephritis and nephrolithiasis 1
• Intestinal pathology such as colitis or diverticulitis extending to the LUQ 1
• Rare causes include intestinal malrotation with abnormally positioned appendix 6

Imaging Modalities to Avoid

• Plain radiography has limited utility for LUQ pain due to low sensitivity, though it may detect pneumoperitoneum or bowel obstruction 1
• Fluoroscopic contrast enema is not recommended as initial imaging for LUQ pain 1
• MRI, while accurate, is not recommended for initial evaluation of acute LUQ pain due to:
  • Longer acquisition time
  • Less sensitivity for extraluminal air
  • Motion artifacts in symptomatic patients
  • Need for screening for contraindications 1

Clinical Pearls

• Always consider the patient's age, sex, and clinical presentation when selecting imaging modality 1
• CT with IV contrast improves detection of bowel wall pathology, pericolic abnormalities, vascular pathology, and intraabdominal fluid collections 1
• Laboratory tests should guide but not replace appropriate imaging studies when clinically indicated 5
• The American College of Radiology Appropriateness Criteria should be used to guide imaging selection 7

Common Pitfalls

• Relying solely on plain radiographs which have poor sensitivity for most causes of LUQ pain 1
• Failing to use contrast enhancement when evaluating for vascular pathologies or abscesses 1
• Not considering atypical presentations of common conditions (e.g., appendicitis in cases of intestinal malrotation) 6
• Delaying appropriate imaging in elderly patients who may present with atypical symptoms and normal laboratory values 1