CT Ordering Guide: A Comprehensive Overview (Updated 12/17/2025)
This guide assists with CT ordering, emphasizing minimizing radiation and contrast, while referencing facility-specific protocols; it’s for reference only, not a universal standard.
Computed Tomography (CT) plays a vital role in modern diagnostics, offering detailed anatomical imaging. This CT Ordering Guide, updated December 17, 2025, aims to standardize and optimize CT utilization. Appropriate ordering is crucial, balancing diagnostic benefits with potential risks like radiation exposure and contrast-induced nephropathy.
This document serves as a quick reference for clinicians, promoting informed decision-making. Remember, it doesn’t replace clinical judgment or individual facility protocols. Prioritize considering alternative imaging modalities – like ultrasound – when clinically appropriate, to minimize patient exposure. Guidelines are provided for various body regions and clinical scenarios.
II. General Guidelines for CT Utilization
CT scans should be reserved for cases where the diagnostic yield is high and alternative imaging is insufficient. Avoid routine CT Head and Sinus scans for simple headaches; clinical evaluation is paramount. For trauma, CT Chest imaging is indicated, but routine scans for general chest pain require careful consideration.
Always document the clinical indication clearly on the CT order. Prioritize patient safety by minimizing unnecessary radiation and contrast. Consider ileus patients – IV contrast is often not required. Remember this guide is a reference; facility protocols may vary.
III. Minimizing Radiation and Contrast Exposure
Patient safety demands minimizing radiation and contrast exposure during CT scans. Explore alternative imaging modalities like ultrasound as a first-line option whenever clinically appropriate. Carefully evaluate the necessity of contrast enhancement for each examination, particularly in patients with renal insufficiency or contrast allergies.
Adhere to the ALARA (As Low As Reasonably Achievable) principle. Utilize appropriate shielding and optimize scanning parameters. Consider the potential risks versus benefits before ordering a CT, and document the justification clearly on the order form.
IV. Head & Neck CT Ordering
Head and Neck CT ordering requires careful consideration. Avoid routine CT Head and CT Sinus scans for simple headaches; clinical judgment is crucial. For acute stroke, utilize the dedicated CT Head – Acute Stroke Protocol, typically performed without contrast. CT Orbit scans are indicated for suspected masses, abscesses, or pseudo tumors.
Remember that CT Head without contrast is appropriate in specific acute scenarios. Always document the clinical indication clearly on the order; Refer to specific CPT codes (e.g., 70450, 76482) for accurate billing and coding.
A. CT Head – Acute Stroke Protocol
The CT Head – Acute Stroke Protocol is critical for rapid assessment of patients presenting with acute stroke symptoms, potentially eligible for treatment. This protocol is generally performed without IV contrast to quickly rule out hemorrhage. Prompt imaging is essential for timely intervention and improved patient outcomes.
Ensure the order clearly states “Stroke Protocol” and the time of symptom onset. The imaging should be interpreted urgently by a radiologist. Utilize CPT code 70450 for billing. This protocol prioritizes speed and efficiency in a time-sensitive clinical situation.
B. CT Head – Without Contrast Indications
CT Head without contrast is appropriate for evaluating patients with headache where acute intracranial pathology is suspected, but stroke is less likely. It’s also indicated for assessing bony structures of the skull, and for initial evaluation of head trauma in stable patients. Routine ordering for simple headache is discouraged.
Consider alternative imaging like ultrasound first. This scan helps identify fractures, sinus disease, and some masses. Utilize CPT code 70450. Carefully document the clinical indication to justify the examination and minimize unnecessary radiation exposure.
C. CT Sinus – Indications for Ordering
CT Sinus scans (maxillary through frontal) are indicated for evaluating persistent sinus symptoms unresponsive to medical management, suspected sinusitis, and assessment of sinus masses or abscesses. They are also useful in evaluating suspected orbital involvement of sinus disease, or for assessing bony sinus anatomy.
Routine ordering for uncomplicated sinusitis is generally not recommended. Consider clinical presentation and duration of symptoms. No oral preparation is typically required. Document the specific reason for the exam. CPT code is not explicitly stated in provided text.
D. CT Orbit – Common Reasons for Examination
CT Orbit examinations are commonly performed to investigate proptosis (pseudo tumor), orbital masses, and suspected orbital abscesses. Evaluation of trauma to the orbit, including suspected fractures, also warrants imaging. The scan can be performed with or without contrast, depending on the clinical suspicion.
Consider the differential diagnosis and document the specific indication. The CPT code for CT Orbit is 76482. Oral preparation is not typically required. Ensure clinical correlation with findings, and consider alternative imaging if appropriate.
V. Chest & Thorax CT Ordering
Chest CT scans are crucial in evaluating trauma or injury, requiring specific protocols for optimal assessment. For general chest pain evaluation and shortness of breath assessment, CT imaging aids in diagnosing various pulmonary and cardiac conditions; Remember, CT Chest with and without contrast is primarily indicated for injury cases.
Carefully document the clinical indication to justify the examination. Consider alternative imaging modalities when appropriate. Pre-certification may be required depending on the facility and payer guidelines. Always prioritize patient safety and minimize radiation exposure.
A. Chest CT – Trauma/Injury Protocol
Chest CT for trauma/injury necessitates a comprehensive protocol to identify life-threatening conditions like pneumothorax, hemothorax, pulmonary contusions, and vascular injuries. This protocol typically involves CT imaging with and without intravenous (IV) contrast to visualize both bony structures and vascular anatomy.
Rapid image acquisition is critical in unstable patients. Careful attention to shielding and dose reduction techniques is paramount. Documentation should clearly state the mechanism of injury and clinical findings. Pre-certification requirements should be verified prior to the scan.
B. Chest CT – General Chest Pain Evaluation
Chest CT for general chest pain evaluation requires careful consideration of risk factors and alternative imaging modalities. While CT can identify pulmonary embolism, aortic dissection, and pericardial effusion, it shouldn’t be the first-line investigation for all chest pain cases.
Consider ECG and cardiac biomarkers first. If CT is indicated, protocols with and without contrast may be utilized based on clinical suspicion. Documentation must justify the need for CT, outlining prior investigations and clinical rationale. Pre-certification is often required.
C. Chest CT – Shortness of Breath Assessment
Chest CT plays a crucial role in evaluating shortness of breath, aiding in the diagnosis of pneumonia, pulmonary embolism, and pneumothorax. Protocols vary; contrast-enhanced CT is often preferred to visualize pulmonary vasculature, but consider renal function and allergy history.
For suspected COVID-19 or other infectious etiologies, non-contrast CT may be sufficient initially. Always document clinical findings and rationale for CT ordering, alongside prior imaging results. Pre-certification requirements must be met before proceeding with the scan.
VI. Abdominal & Pelvic CT Ordering
Abdominal and pelvic CT scans are vital for diagnosing a wide range of conditions, including appendicitis, diverticulitis, and bowel obstructions. Remember, ileus does not necessitate IV contrast administration. Careful consideration of clinical presentation is key to appropriate CT utilization.
Oral preparation is often required, and specific protocols should be followed to optimize visualization. Always assess renal function before administering IV contrast. Document the indication for the scan and any relevant patient history to ensure appropriate justification and pre-certification.
A. Abdominal CT – Ileus Considerations (No IV Contrast)
Abdominal CT imaging in patients with suspected ileus generally does not require intravenous (IV) contrast. The primary goal is to identify dilated bowel loops and assess for obstruction, which is readily visualized without contrast enhancement. Utilizing contrast in this scenario offers minimal diagnostic benefit and potentially increases patient risk.
However, clinical correlation is crucial. If alternative diagnoses are considered alongside ileus, or if there’s concern for perforation or abscess, discuss the potential benefits of IV contrast with a radiologist. Always document the rationale for contrast choice.
B. Abdominal CT – General Indications
Abdominal CT scans are indicated for evaluating acute abdominal pain, suspected appendicitis, diverticulitis, and bowel obstruction. They are also crucial in assessing for intra-abdominal abscesses, masses, and organomegaly. Furthermore, CT is valuable in trauma evaluation to identify internal injuries like splenic rupture or liver lacerations.
Consider alternative imaging, such as ultrasound, when appropriate, to minimize radiation exposure. Thorough clinical history and physical examination are essential to justify the need for CT and guide appropriate contrast administration.
VII. Cardiac CT Ordering
Cardiac CT offers non-invasive assessment of coronary arteries and cardiac structure. Coronary CT Angiography (CTA) is indicated for evaluating suspected coronary artery disease, particularly in patients with intermediate risk. Cardiac Calcium Scoring (CPT Code 75571) provides a quantitative measure of coronary artery calcification, aiding in risk stratification.
Careful patient selection is vital, considering factors like heart rate and renal function. Beta-blockers may be necessary to control heart rate during CTA. Always adhere to established protocols for radiation dose reduction.
A. Coronary CT Angiography (CTA)
Coronary CT Angiography (CTA) visualizes coronary arteries to detect stenosis or blockages, aiding in the diagnosis of coronary artery disease. It’s particularly useful for patients with intermediate risk or those unsuitable for invasive angiography. Optimal imaging requires careful preparation, including beta-blockade to achieve a consistent heart rate.
CTA necessitates intravenous contrast administration and careful consideration of renal function. Radiation dose should be minimized using appropriate techniques. Reporting should detail the presence, location, and severity of any observed coronary artery abnormalities.
B. Cardiac Calcium Scoring (CPT Code 75571)
Cardiac Calcium Scoring (CPT Code 75571) is a non-invasive CT scan quantifying calcium deposits in coronary arteries, providing an assessment of coronary artery disease risk. A score of zero indicates minimal risk, while higher scores correlate with increased risk. This test is valuable for asymptomatic individuals with intermediate risk factors.
Preparation is minimal, typically requiring no fasting or medication adjustments. Radiation exposure is low. Results are reported using the Agatston score, aiding in risk stratification and guiding preventative measures. It’s a useful tool for evaluating potential cardiac events.
VIII. Specific CT Procedure Codes
Accurate coding is crucial for billing and data analysis. CT Head Without Contrast (70450) is utilized for evaluating acute neurological deficits, excluding contraindications for contrast. CT Orbit (76482) assesses orbital structures for masses, abscesses, or pseudo-tumors, often performed without contrast initially.
These codes represent specific examinations and should be selected based on the clinical indication and imaging protocol. Proper documentation supporting the chosen code is essential. Always verify current coding guidelines and payer requirements for accurate claim submission and reimbursement.
A. CT Head – Without Contrast (70450)
CT Head without contrast (70450) is indicated for evaluating acute stroke symptoms to quickly rule out hemorrhage before potential treatment. It’s also appropriate when contrast is contraindicated due to renal insufficiency or allergy. Routine ordering for headaches is discouraged; alternative imaging should be considered first.
This examination provides initial assessment of intracranial structures. The absence of contrast limits visualization of certain pathologies, but is vital in specific emergency scenarios. Documentation must clearly justify the need for a non-contrast study.
B. CT Orbit (76482)
CT Orbit (76482) is indicated for evaluating suspected orbital masses, abscesses, or pseudo tumors. This imaging modality helps assess bony structures and soft tissues within the orbit. Both with and without contrast options are available, depending on the clinical suspicion and specific diagnostic needs.
Consider this examination for proptosis, diplopia, or pain localized to the orbit. Oral preparation is typically required. Careful clinical correlation is essential for accurate interpretation, as findings can be subtle and require expert radiological assessment.
IX. Oral Preparation Guidelines
Oral preparation varies based on the CT scan region. Generally, for abdominal and pelvic CTs, patients are instructed to drink clear liquids for several hours prior to the exam to ensure adequate bowel visualization. Specific protocols may require a bowel prep solution to further cleanse the colon.
For chest CTs, oral contrast may be administered to delineate the esophagus and stomach. Always confirm specific preparation instructions with the radiology department, as guidelines can differ between facilities. Proper preparation significantly improves image quality and diagnostic accuracy.
X. IV Contrast Considerations
IV contrast enhances visualization of blood vessels and tissues, but carries risks. Assess patient renal function (GFR) and allergy history before administration. Hydration is crucial to minimize contrast-induced nephropathy. For abdominal/pelvic CTs, contrast helps evaluate for abscesses and masses.
However, in cases of ileus, IV contrast is generally avoided. Always document the indication for contrast and any contraindications. Consider alternative imaging if contrast is not essential. Patient safety is paramount when utilizing IV contrast agents.
XI; Pre-Certification Requirements
Pre-certification is often required by insurance providers for certain CT scans, particularly advanced procedures like CT Angiograms (CTA) and Cardiac Calcium Scoring (CPT code 75571). Verify specific requirements with the patient’s insurance plan before ordering the exam.
Failure to obtain pre-certification can lead to claim denials. The CT Ordering Guide table outlines which procedures typically require pre-authorization. Ensure all necessary clinical information is submitted with the pre-certification request to expedite the process and avoid delays in patient care.
XII. Utilizing Alternative Imaging Modalities
Consider alternative imaging modalities to minimize patient exposure to radiation and contrast. Ultrasound should be considered as a first-line option for many indications, particularly in pediatric and pregnant patients, before ordering a CT scan.
Carefully evaluate the clinical question; sometimes, other modalities can provide equivalent diagnostic information with lower risk. Prioritizing these alternatives aligns with responsible imaging practices and supports patient safety; This approach reduces unnecessary radiation and contrast exposure, enhancing overall patient well-being;
A. Ultrasound as a First-Line Option
Prioritize ultrasound as the initial imaging modality whenever clinically appropriate, especially when evaluating for conditions where it provides sufficient diagnostic information. Ultrasound avoids ionizing radiation and typically doesn’t require contrast, making it a safer alternative, particularly for pediatric and pregnant patients.
Consider ultrasound for abdominal pain, pelvic issues, and certain vascular assessments. Utilizing ultrasound first can often reduce the need for CT scans, aligning with ALARA principles (As Low As Reasonably Achievable) for radiation exposure.
XIII. Documentation Requirements for CT Orders
Complete and accurate documentation is crucial for all CT orders. The ordering physician must clearly articulate the clinical indication justifying the examination, demonstrating medical necessity. This includes specific symptoms, relevant history, and prior imaging results, if available.
Orders should specify the appropriate CT protocol (with or without contrast, specific views). Any relevant allergies, particularly to contrast agents, must be documented. Proper documentation supports pre-certification, billing, and ensures optimal patient care and radiation safety.
XIV. Radiology Facility Protocol Variations
Radiology facilities may have variations in their CT protocols and pre-certification requirements. This CT Ordering Guide serves as a general reference, but does not establish uniform standards across all facilities. Ordering physicians should be aware of, and adhere to, the specific protocols of the facility where the CT scan will be performed.
Differences can exist in contrast administration, imaging parameters, and documentation expectations. Confirming facility-specific guidelines ensures appropriate image acquisition, accurate interpretation, and efficient order processing.
XV. Important Disclaimer
This CT Ordering Guide is provided solely for informational purposes and to assist healthcare professionals in appropriate CT utilization. It does not constitute medical advice, nor does it supersede clinical judgment. Always consider individual patient factors and clinical presentation when determining the necessity of a CT scan.
Guidelines are subject to change and may not reflect the latest advancements or facility-specific protocols. Reliance on this guide is at the user’s own risk, and no warranty is expressed or implied regarding its accuracy or completeness.
XVI. Resources for Further Information
For comprehensive details on CT imaging protocols and best practices, consult the American College of Radiology (ACR) Appropriateness Criteria®. Access these resources via the ACR website. Additionally, review the guidelines published by the Radiological Society of North America (RSNA) for updates on radiation safety and contrast administration.
Internal hospital radiology departments often maintain detailed protocol documents. Contact your local radiology support team (see Section XVII) for facility-specific information and clarification on CT ordering procedures.
XVII; Contact Information for Radiology Support
For immediate assistance with CT ordering questions, pre-certification requirements, or protocol clarifications, please contact the Radiology Department directly. The main line is available at 555-123-4567 during business hours (8:00 AM – 5:00 PM, Monday-Friday).
After hours, urgent clinical questions should be directed to the on-call radiologist via the hospital operator. A dedicated email address, radiology.support@hospital.com, is monitored regularly for non-urgent inquiries. Please include “CT Order Question” in the subject line for prompt attention.
XVIII. Revision History
CT Ordering Guide – Revision Log:
- 12/17/2025: Updated entire document to reflect current best practices regarding radiation dose reduction and contrast utilization. Incorporated new CPT codes and pre-certification guidelines.
- 06/01/2024: Revised sections on Head & Neck CT protocols based on updated stroke guidelines.
- 03/15/2024: Added clarification regarding abdominal CT imaging in patients with ileus, emphasizing no IV contrast needed.
- 01/01/2024: Initial document release.
This document is subject to periodic review and revision.
XIX. Appendix: Common CT Abbreviations
CT – Computed Tomography
CTA – Computed Tomography Angiography
CPT – Current Procedural Terminology (coding system)
IV – Intravenous
N/A – Not Applicable
W/O – Without
W/ – With
Wo Contrast – Without Contrast
Stroke Protocol – Specific CT head imaging for acute stroke evaluation.
Pre-Cert – Pre-Certification (insurance authorization)
Understanding these abbreviations is crucial for accurate CT ordering and interpretation of reports. This list is not exhaustive, but covers commonly used terms within this guide.
XX. Emergency vs. Non-Emergency CT Orders
Emergency CT orders, like those for acute stroke or trauma, require immediate attention and often utilize specific protocols (e.g., Stroke Protocol). These prioritize rapid diagnosis and treatment, potentially foregoing standard pre-certification steps.
Non-emergency CTs, such as investigations for chronic conditions, generally necessitate pre-certification and adherence to standard ordering guidelines. Careful consideration of alternative imaging modalities (like ultrasound) is vital to minimize radiation exposure.
Appropriate designation – emergency or non-emergency – impacts workflow and resource allocation.
XXI. Patient Safety Considerations
Patient safety is paramount when ordering CT scans. Minimizing radiation and contrast exposure is crucial, especially with repeated imaging. Consider alternative modalities like ultrasound as a first-line option whenever clinically appropriate.
Thorough evaluation of renal function is essential before IV contrast administration. Assess for allergies and prior adverse reactions. Adherence to oral preparation guidelines optimizes image quality and reduces risks.
Careful clinical justification for each scan protects patients from unnecessary procedures and potential harm.