74150

Computed tomography, abdomen; without contrast material

Computed tomography (CT) of the abdomen without the administration of intravenous (IV) contrast material. This diagnostic imaging procedure utilizes X-rays from multiple angles to create detailed cross-sectional images of the abdominal organs, including the liver, spleen, kidneys, pancreas, gastrointestinal tract, blood vessels, and surrounding structures, from the diaphragm to the iliac crest. It is performed to identify pathology based on differences in tissue density, detect calcifications (e.g., kidney stones, vascular calcifications), assess for fluid collections, or evaluate for anatomical abnormalities without the need for contrast enhancement. Oral or rectal contrast agents, if utilized for gastrointestinal opacification, do not change the 'without contrast material' designation for this code.

Clinical Indications

  • Evaluation of acute or chronic abdominal pain, especially when other imaging (e.g., ultrasound) is inconclusive or if IV contrast is contraindicated.
  • Detection and characterization of nephrolithiasis (kidney stones) and other urinary tract calculi.
  • Assessment of suspected acute appendicitis or diverticulitis when contrast is contraindicated or not initially required.
  • Diagnosis and staging of bowel obstruction or ileus.
  • Initial assessment of blunt abdominal trauma to evaluate for organ injury or hemorrhage.
  • Follow-up or surveillance of known abdominal masses, cysts, or calcifications where contrast enhancement is not critical for evaluation.
  • Evaluation of ascites or other abdominal fluid collections.
  • Assessment for retroperitoneal fibrosis.
  • Detection of pancreatic calcifications or early signs of pancreatitis (though contrast often preferred for full evaluation).
  • Pre-operative planning for certain abdominal procedures.

Procedure Steps

  1. Patient positioning: The patient lies supine on the CT scanner table, often with arms raised above the head.
  2. Scout image acquisition: A preliminary low-dose X-ray (topogram or localizer) is obtained to define the exact anatomical region for scanning.
  3. Parameter setting: The technologist sets specific imaging parameters (e.g., kVp, mAs, slice thickness) according to the diagnostic need and established protocols.
  4. Image acquisition: The CT scanner acquires axial or helical (spiral) images of the abdomen, typically extending from the diaphragm to the iliac crest, without the administration of intravenous contrast.
  5. Image reconstruction: Raw data are processed by a computer to generate cross-sectional images that can be viewed in axial, coronal, and sagittal planes.
  6. Image review and interpretation: A radiologist reviews the reconstructed images, identifies any abnormalities, and generates a diagnostic report.

Coding Guidelines

  • Code 74150 is used when computed tomography of the abdomen is performed exclusively without intravenous contrast material. If any intravenous contrast is administered, this code is not appropriate.
  • If the study involves a CT of the abdomen followed by a CT of the abdomen with contrast, code 74170 (Computed tomography, abdomen; without contrast material, followed by with contrast material(s) and further sections) should be used, not 74150 and 74160 separately.
  • Oral or rectal contrast material (e.g., barium, Gastrografin) administered for opacification of the gastrointestinal tract is considered an integral part of the CT study and does not change the 'without contrast material' designation for intravenous contrast purposes.
  • This code specifically covers the abdomen. If the pelvis is also included in the scan without contrast, a combined code such as 74176 (Computed tomography, abdomen and pelvis; without contrast material) should be utilized.
  • Documentation in the patient's medical record must clearly support the medical necessity for the CT scan and explicitly state that no intravenous contrast was used.
  • CPT code 74150 includes both the technical component (equipment, supplies, and technician services) and the professional component (physician interpretation and report) unless modifier -26 (Professional Component) or -TC (Technical Component) is appended when billed separately.

Associated ICD-10 Codes