71250

Computed Tomography (CT) of the Thorax without Contrast

Computed tomography (CT) of the thorax, designated by CPT code 71250, is a highly sophisticated non-invasive diagnostic imaging procedure that utilizes specialized X-ray technology to generate detailed cross-sectional images of the chest. The procedure is performed without the administration of intravenous or oral contrast material. During the scan, the patient lies on a motorized table that moves through a doughnut-shaped gantry. Inside the gantry, an X-ray source rotates rapidly around the patient, emitting thin beams of radiation that pass through the body and are captured by high-sensitivity detectors on the opposite side. This data is then processed by a computer using complex algorithms to create thin 'slices' of the thoracic cavity, including the lungs, heart, mediastinum, pleural spaces, and the chest wall. Because this specific scan is performed without contrast, it is particularly indicated for evaluating lung parenchyma, detecting interstitial lung disease, identifying pulmonary nodules, and assessing skeletal structures such as the ribs, sternum, and thoracic spine for fractures or degenerative changes. It is also the preferred modality for patients with contraindications to iodinated contrast, such as severe renal insufficiency or a history of anaphylactic reactions to contrast media. The resulting high-resolution images allow radiologists to visualize anatomical structures with significantly greater detail than standard planar X-rays, aiding in the diagnosis of acute conditions like pneumonia or pneumothorax, as well as the management of chronic conditions like chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis. The procedure is efficient, typically taking less than 10 minutes, and provides vital clinical intelligence for treatment planning in both emergency and elective settings.

Clinical Indications

  • Evaluation of acute or chronic shortness of breath (dyspnea)
  • Persistent or chronic cough of unknown etiology
  • Suspected pulmonary nodules or masses found on standard X-ray
  • Staging and follow-up of known thoracic malignancies
  • Screening and monitoring of interstitial lung disease (ILD)
  • Assessment of thoracic trauma, including suspected rib or sternal fractures
  • Detection of pneumothorax, hemothorax, or pleural effusion
  • Evaluation of mediastinal lymphadenopathy
  • Pre-operative planning for thoracic surgery
  • Monitoring the progression of chronic obstructive pulmonary disease (COPD) or emphysema

Procedure Steps

  1. The patient is identified and verified for the correct procedure according to safety protocols.
  2. Patient is asked to remove any metal objects, jewelry, or clothing with metal fasteners that could cause artifacts.
  3. The patient is positioned supine (on their back) on the CT scanner table with arms typically raised above the head to minimize interference.
  4. A 'scout' or 'topogram' image is obtained to define the anatomical range for the scan, typically from the lung apices to the adrenal glands.
  5. The CT gantry rotates around the patient as the table moves through, capturing axial data slices without the use of contrast media.
  6. The patient is instructed to hold their breath for several seconds during the scan to minimize respiratory motion artifacts.
  7. Raw data is reconstructed into various imaging planes, such as axial, coronal, and sagittal, using specific filters (e.g., bone or lung kernels).
  8. Images are transferred to a Picture Archiving and Communication System (PACS) for radiologist interpretation.
  9. Post-processing techniques like Maximum Intensity Projection (MIP) may be applied for better visualization of pulmonary nodules.

Coding Guidelines

  • Report 71250 for a CT scan of the thorax performed without intravenous contrast material.
  • If the scan is performed with contrast, use CPT code 71260 instead.
  • If the scan is performed without contrast followed by contrast material and further sections, use CPT code 71270.
  • Do not report 71250 in conjunction with 71271 (low dose CT for lung cancer screening) during the same session.
  • Use modifier 26 if only the professional component (interpretation) is being billed by the physician.
  • Use modifier TC if only the technical component (equipment and staff) is being billed by the facility.
  • For 3D rendering and interpretation, refer to codes 76376 or 76377; however, ensure documentation supports the medical necessity beyond standard reconstructions.
  • Ensure the diagnosis code (ICD-10) accurately reflects the medical necessity for a non-contrast study versus a contrast-enhanced study.

Associated ICD-10 Codes