Imaging Guidelines for Left Lower Rib and Upper Left Abdominal Pain

Rationale for CT Abdomen and Pelvis with IV Contrast

The American College of Radiology recommends CT abdomen and pelvis with IV contrast as the initial imaging for patients with acute abdominal pain, providing a comprehensive evaluation of abdominal and thoracic structures, with high sensitivity and specificity (up to 98% accuracy) for diagnosing various causes of left-sided abdominal and lower chest pain 1, 2
IV contrast improves the characterization and detection of subtle bowel wall abnormalities and complications such as abscesses, according to the American College of Radiology 2
CT can identify alternative diagnoses that may present with similar clinical symptoms, avoiding misdiagnosis, as suggested by the American College of Radiology 2

Diverticulitis is a common cause of left lower quadrant pain that may radiate to the left lower rib area, according to the American College of Radiology 1, 2
Diaphragmatic hernia can present with pain in the lower chest or upper abdomen, as reported by the World Journal of Emergency Surgery 3, 4
Visceral pathology (splenic, gastric, pancreatic, or colonic issues) should be considered as a potential cause of left-sided abdominal pain, according to the American College of Radiology 1

Ultrasound may be useful for specific conditions but has limited value as the initial imaging for non-gynecologic left-sided abdominal pain, as stated by the American College of Radiology 1
MRI is not recommended for initial evaluation of acute abdominal pain due to its limited sensitivity for extraluminal air and calculi, time-consuming nature, requirement for metal screening, and susceptibility to motion artifacts, according to the American College of Radiology 1

Low-dose CT techniques can achieve radiation dose reduction of 75-90% compared to standard-dose CT while maintaining similar sensitivity and specificity, as reported by the American College of Radiology 2
Administration of oral or colonic contrast may be helpful for bowel luminal visualization in addition to IV contrast, as suggested by the American Academy of Family Physicians 5

If there is concern for diaphragmatic hernia, CT scan with contrast enhancement of the chest and abdomen is strongly recommended (1B evidence), according to the World Journal of Emergency Surgery 3
For female patients of childbearing age, consider pelvic ultrasound first if gynecologic pathology is suspected, as recommended by the American College of Radiology 1, 2
In patients with renal insufficiency, CT without IV contrast may be considered, though this is less optimal, as stated by the American College of Radiology 6, 7

Relying solely on clinical assessment for diagnosis of abdominal pain can lead to misdiagnosis rates of 34-68%, according to the American College of Radiology 1
Overlooking diaphragmatic injuries, which can be missed on plain radiographs in up to 62% of cases, as reported by the World Journal of Emergency Surgery 3