Standard Abdominal X-Ray Protocol
For a patient with no specified medical history presenting for abdominal X-ray, order a supine anteroposterior (AP) view of the abdomen as the standard single projection, recognizing that this imaging modality has significant limitations and should be reserved for specific clinical indications rather than routine screening.
Standard Imaging Protocol
Single Projection Approach
- Supine AP abdominal radiograph is the standard initial view, providing adequate diagnostic information for most indications while minimizing radiation exposure 1
- The supine position delivers approximately 50% less radiation dose (0.2 mSv) compared to erect positioning (0.4 mSv) 1
- Image quality is superior in the supine position, with 27% better visual quality scores and 16% higher contrast-to-noise ratio compared to erect views 1
When to Add Additional Views
Add an erect abdominal view only when specifically evaluating for:
Lateral and AP projections are indicated for:
- Suspected retained anorectal foreign body (to determine shape, size, location, and presence of pneumoperitoneum) 2
Critical Limitations to Communicate
Poor Diagnostic Performance
- Abdominal radiography has 50-60% diagnostic sensitivity for small bowel obstruction, with 20-30% inconclusive results and 10-20% misleading findings 2
- For acute abdominal pain evaluation, plain films demonstrate low sensitivity and accuracy across most pathologies 3, 4
- The false-negative rate can be substantial—for example, 32% for pelvic fractures when compared to CT 5
Specific Clinical Contexts Where Plain Films Have Limited Value
- Acute abdomen workup: Most examinations yield normal or nonspecific findings, bringing appropriateness into question 4
- Post-bariatric surgery patients: Plain abdominal X-ray has only a limited role when CT is unavailable, capable of detecting bowel distension or fluid levels but missing critical complications 2
- Inflammatory bowel disease: Radiographs provide only indirect evidence and should be reserved for severely ill patients to assess for perforation or obstruction 2
When Plain Radiography Remains Appropriate
Acceptable Indications
- Suspected bowel obstruction when CT is not immediately available 2
- Suspected perforated viscus (though CT is more sensitive) 2
- Urinary tract stones evaluation 2
- Ingested foreign body localization 2
- Retained anorectal foreign body as initial imaging before digital rectal examination 2
Important Caveat
For over 30 years, scientific literature has recommended reducing both the number of examinations and projections to decrease radiation dose, patient inconvenience, and costs 4. There is evidence suggesting no place for routine plain abdominal radiography in adult emergency department patients with acute abdominal pain in current practice 3.
Superior Alternative Imaging
When to Skip Plain Films Entirely
- Contrast-enhanced CT with oral contrast is the study of choice for acute abdomen evaluation, providing superior diagnostic accuracy 2
- Point-of-care ultrasound is more useful for evaluating gallbladder pathology, appendicitis, free fluid, or intestinal distention 2
- In stable patients who will undergo CT scanning during initial resuscitation, routine pelvic radiography is unnecessary 5
CT Advantages Over Plain Films
- CT changed the leading diagnosis in 49% of patients, altered admission status in 24%, and modified surgical plans in 25% in emergency presentations 2
- For bowel obstruction, CT provides critical information about the level, cause, and presence of complications that plain films cannot reliably detect 2
Practical Ordering Guidance
Standard wording for requisition: "Supine AP abdomen" or "Single view abdomen, supine"
Add erect view only if: Clinical suspicion for perforation or obstruction AND CT unavailable or contraindicated
Consider skipping entirely if: Patient will undergo CT scanning as part of workup, as this provides definitive imaging 3, 4