GENERAL INFORMATION
It is an expectation that all patients receive care/services from a licensed clinician.  All appropriate supporting documentation, including recent pertinent office visit notes, laboratory data, and results of any special testing must be provided.  If applicable: All prior relevant imaging results and the reason that alternative imaging cannot be performed must be included in the documentation submitted. 

Where a specific clinical indication is not directly addressed in this guideline, medical necessity determination will be made based on widely accepted standard of care criteria. These criteria are supported by evidence-based or peer-reviewed sources such as medical literature, societal guidelines and state/national recommendations.

Purpose
Computed tomography angiography (CTA) generates images of the blood vessels (arteries and/or veins) in the chest that can be evaluated for evidence of stenosis, occlusion,
embolism, dissection and/or aneurysms. Chest CTA (non-coronary) is used to evaluate the arteries outside the heart in the chest (thorax). CTA uses ionizing radiation and requires the administration of iodinated contrast agent, which is a potential hazard in patients with impaired renal function.

NOTE: Authorization for CT Angiography covers both arterial and venous imaging. The term angiography refers to both arteriography and venography.

Policy 
IINDICATIONS 
Known or Suspected Pulmonary Embolism (PE)^1,2,3,4,5,6

• Suspected pulmonary embolism:
  • High risk for PE based on shock or hypotension, OR a validated pre-test high probability score (such as Well’s > 6, Modified Geneva score > 11),
    • D-dimer is NOT needed for high-risk patients; can approve high-risk even with normal D-dimer.
  • Intermediate and low risk requires elevated D-dimer.
• Follow-up of known pulmonary embolism with either symptoms (such as dyspnea, fatigue, lightheadedness and/or edema) that recur OR are persistent at 3 months following initial diagnosis (Follow-up imaging in asymptomatic patients to determine if embolus has resolved or to determine cessation of anticoagulation is not indicated as imaging changes may persist.)

Thoracic Aortic Disease^{7,8,9,10,11,12}
Suspected Thoracic Aortic Aneurysm (TAA)

• Asymptomatic suspected thoracic aortic aneurysm
  • Based on other imaging such as echocardiogram or chest X-ray
  • Screening in individuals with a personal history of bicuspid aortic valve when TTE (Transthoracic Echocardiogram) is inconclusive or insufficient:¹²
    • Baseline study at diagnosis
    • Every 3 years thereafter
  • Screening in individuals at elevated risk due to family history as below when TTE (Transthoracic Echocardiogram) is inconclusive or insufficient:¹²
    • First-degree relatives of individuals with a known thoracic aortic aneurysm (defined as > 50% above normal) or dissection
    • First and second-degree relatives of individuals with familial thoracic aortic aneurysm and dissection (FTAAD)/nonsyndromic heritable thoracic aortic disease (NS-TAD)
    • First degree relatives of individuals with a known bicuspid aortic valve
  • See Genetic Syndromes and Rare Diseases section for additional indications for screening.
• Symptomatic known or suspected thoracic aortic aneurysm^9,12
  • Signs and symptoms may include:
    • Abrupt onset of severe sharp or stabbing pain in the chest, back or abdomen.
    • Asymmetric blood pressure between limbs.
    • Acute chest or back pain and at high risk for aortic aneurysm and/or aortic syndrome (risk factors include hypertension, atherosclerosis, prior cardiac or aortic surgery, underlying aneurysm, connective tissue disorder [e.g., Marfan syndrome, vascular form of Ehlers-Danlos syndrome, Loeys-Dietz syndrome] and bicuspid aortic valve)
• Suspected vascular cause of dysphagia or expiratory wheezing with other imaging that is suggestive or inconclusive.

Thoracic Aortic Syndromes

• For suspected acute aortic syndrome (AAS) such as aortic dissection, intramural hematoma and penetrating atherosclerotic ulcer:
  • Other imaging (such as echocardiogram) is suggestive of AAS OR
  • Individual is either:
    • High risk and one sign/symptom OR non-high risk and two or more signs/symptoms of AAS:
      • High risk conditions:
        • Marfan's syndrome or other connective tissue disease, family history of aortic disease, known aortic valve disease, recent aortic manipulation and/or known thoracic aortic aneurysm
        • Signs and symptoms concerning for AAS:
          • Chest, back or abdominal pain described as abrupt onset, severe in intensity and/or ripping or tearing in quality
          • Pulse deficit or systolic blood pressure differential
          • Focal neurologic deficit with pain
          • New heart murmur with pain
          • Hypotension or shock
• For follow-up of known aortic syndromes, including aortic dissection, intramural hematoma and penetrating atherosclerotic ulcer: frequency for follow up is as clinically indicated.

Follow-Up of Known Thoracic Aortic Aneurysm

• Baseline study at diagnosis then every 6 – 24 months
  • If there is a change in clinical status or cardiac exam, then imaging sooner than six months is indicated.

Postoperative Follow-up of Aortic Repair¹²

• Follow-up thoracic endovascular aortic repair (TEVAR):
  • Baseline post-EVAR at 1-month post-EVAR
  • Annually thereafter if stable
    • more frequent imaging (as clinically indicated) may be needed if there are complications or abnormal findings on surveillance imaging.
• Follow up open repair at the following intervals:
  • Baseline follow-up study at one year post-operatively
  • Every 5 years thereafter
  • If abnormal findings are seen on any surveillance imaging study, imaging is then done annually.

Vascular Disease^{13,14,15,16,17}

• Superior vena cava (SVC) syndrome
• Subclavian Steal Syndrome after positive or inconclusive ultrasound 
• Thoracic Outlet Syndrome
• Suspected pulmonary hypertension when other testing (echocardiogram or right heart catheterization) is suggestive of the diagnosis

Congenital Malformations^18,19,20,21

• Thoracic malformation on other imaging (chest X-ray, echocardiogram, gastrointestinal study, or inconclusive CT)
• Congenital heart disease with pulmonary hypertension or extra-cardiac vascular anomalies
• Suspected coarctation of the aorta (clinical sign is a disparity in the pulsations and blood pressures in the legs and arms)
• Pulmonary sequestration
  • NOTE: Chest MRA preferred if pediatrics or repeat imaging

Evaluation of Tumor

• When needed for clarification of vascular invasion from tumor

Pre-operative/procedural Evaluation

• Pre-operative evaluation for a planned surgery or procedure (including prior to planned ablation for atrial fibrillation)
• Evaluation of interventional vascular procedures for luminal patency versus restenosis due to conditions such as atherosclerosis, thromboembolism, and intimal hyperplasia
• Evaluation of vascular anatomy prior to solid organ transplantation
• Evaluation prior to endovascular aneurysm repair (EVAR)
• Evaluation prior to Transcatheter Aortic Valve Replacement

Post-operative/procedural Evaluation^22,23

• Follow-up study may be needed to help evaluate a patient’s progress after treatment, procedure, intervention, or surgery. Documentation requires a medical reason that
• clearly indicates why additional imaging is needed for the type and area(s) requested.
• Evaluation of endovascular/interventional abdominal vascular procedures for luminal patency versus restenosis due to conditions such as atherosclerosis, thromboembolism, and intimal hyperplasia
• Evaluation of post-operative complications, e.g., pseudoaneurysms, related to surgical bypass grafts, vascular stents, and stent-grafts in abdomen and pelvis
  • Suspected complications of IVC filter

Genetic Syndromes and Rare Diseases

• For patients with fibromuscular dysplasia (FMD):^24,25
  • One-time vascular study from brain to pelvis
• Vascular Ehlers-Danlos syndrome:^26,27
  • At diagnosis and then every 18 months
  • More frequently if abnormalities are found
• Marfan Syndrome:²⁸
  • At diagnosis and then every 3 years
  • More frequently (annually) if EITHER: history of dissection, dilation of aorta beyond aortic root OR aortic root ascending aorta are not adequately visualized on TTE^12,29
• Loeys-Dietz:³⁰
  • At diagnosis and then every two years
  • More frequently if abnormalities are found
• Williams Syndrome:³¹
  • When there is concern for vascular disease based on abnormal exam or imaging findings (such as diminished pulses, bruits or signs of diffuse thoracic aortic stenosis
• Turner Syndrome
  • Screening with no known vascular abnormality at the following intervals:
    • At diagnosis
    • Every 5 years until age 18
    • Every 10 years in adults
    • Prior to pregnancy/pregnancy planning
  • Annually if any one of the following are present: coarctation of the aorta, aortic dilation, bicuspid aortic valve, hypertension
• Takayasu's Arteritis:³²
  • For evaluation at diagnosis then as clinically indicated
• For other syndromes and rare diseases not otherwise addressed in the guideline, coverage is based on a case-by-case basis using societal guidance.

Combination Studies
Abdominal Aorta CT Angiography with Lower Extremity Runoff and Chest CTA

• To evaluate for an embolic source of lower extremity vascular disease when other imaging such as echocardiography suggests a cardiac source of the embolism.
• Williams Syndrome: When there is concern for vascular disease (including renal artery stenosis) based on abnormal exam or imaging findings (such as diminished pulses, bruits or signs of diffuse thoracic aortic stenosis)³¹

Brain/Neck/Chest/Abdomen and Pelvis CTA

• For patients with fibromuscular dysplasia (FMD), a one-time vascular study from brain to pelvis^24,25
• Vascular Ehlers-Danlos syndrome: At diagnosis and then every 18 months; more frequently if abnormalities are found^26,27
• Loeys-Dietz: at diagnosis and then every two years, more frequently if abnormalities are found³⁰
• For assessment in patients with spontaneous coronary artery dissection (SCAD), can be done at time of coronary angiography³³

Chest/Abdomen CTA

• Evaluation of extensive vascular disease involving the chest and abdominal cavities when pelvic imaging is not needed
• Significant post-traumatic or post-procedural vascular complications when pelvic imaging is not needed

Chest and Abdomen or Abdomen and Pelvis CTA

• Evaluation prior to endovascular aneurysm repair (EVAR) when thoracic involvement is present
• Evaluation prior to Transcatheter Aortic Valve Replacement (TAVR)³⁴
• Marfan syndrome:^28,12,29
  • At diagnosis and every 3 years
  • More frequently (annually) if EITHER: history of dissection, dilation of aorta beyond aortic root OR aortic root/ascending aorta are not adequately visualized on TTE (i.e. advanced imaging is needed to monitor the thoracic aorta)^12,29
• Williams Syndrome³¹
  • When there is concern for vascular disease (including renal artery stenosis) based on abnormal exam or imaging findings (such as diminished pulses, bruits or signs of diffuse thoracic aortic stenosis)
• Acute aortic dissection³⁵
• Significant post-traumatic or post-procedural vascular complications reasonably expected to involve the chest, abdomen and pelvis

Chest CTA and Chest CT (or MRI)

• When needed for clarification of vascular invasion from tumor

Neck/Chest/Abdomen and Pelvis CTA

• Takayasu's Arteritis: For evaluation at diagnosis then as clinically indicated³²

Further Evaluation of Indeterminate Findings on Prior Imaging
Unless follow-up is otherwise specified within the guideline:

• For initial evaluation of an inconclusive finding on a prior imaging report that requires further clarification
• One follow-up exam of a prior indeterminate MR/CT finding to ensure no suspicious interval change has occurred. (No further surveillance unless specified as highly suspicious or change was found on last follow-up exam.)

Rationale/Background
Contraindications and Preferred Studies

• Contraindications and reasons why a CT/CTA cannot be performed may include: impaired renal function, significant allergy to IV contrast, pregnancy (depending ontrimester).
• Contraindications and reasons why an MRI/MRA cannot be performed may include: impaired renal function, claustrophobia, non-MRI compatible devices (such as noncompatible defibrillator or pacemaker), metallic fragments in a high-risk location, patient exceeds weight limit/dimensions of MRI machine.

Clinical Assessment of Pulmonary Embolism 

Wells Score (4)

Probability based on total score: > 6.0 = high, 2.0 - 6.0 = moderate, < 2.0 = Low

Revised Geneva Score (4)

Probability based on total score: 0 – 3 = low probability, 4 – 10 = intermediate probability, ≥ 11 = high probability

References

1. American College of Radiology. ACR Appropriateness Criteria® Suspected Pulmonary Embolism. 2022; 2022:
2. Duffett L, Castellucci L, Forgie M. Pulmonary embolism: update on management and controversies. BMJ. 2020; 370: true. 10.1136/bmj.m2177.
3. Moore A, Wachsmann J, Chamarthy M, Panjikaran L, Tanabe Y. Imaging of acute pulmonary embolism: an update. Cardiovasc Diagn Ther. Jun 2018; 8: 225-243. 10.21037/cdt.2017.12.01.
4. Tak T S U L J Y. Acute Pulmonary Embolism: Contemporary Approach to Diagnosis, Risk-Stratification, and Management. International Journal of Angiology. 2019; 28: 100 - 111. 10.1055/s-0039-1692636.
5. Konstantinides S V, Torbicki A, Agnelli G, Danchin N, Fitzmaurice D et al. 2014 ESC guidelines on the diagnosis and management of acute pulmonary embolism. Eur Heart J. 2014; 35: 3033-69, 3069a-3069k. 10.1093/eurheartj/ehu283.
6. Rivera-Lebron B, McDaniel M, Ahrar K, Alrifai A, Dudzinski D M et al. Diagnosis, Treatment and Follow Up of Acute Pulmonary Embolism: Consensus. Clinical and applied thrombosis/hemostasis: official journal of the. 2019; 25: 1076029619853037.
7. Ferreira Tda A, Chagas I, Ramos R, Souza E. Congenital thoracic malformations in pediatric patients: two decades of experience. J Bras Pneumol. Mar-Apr 2015; 41: 196-9. 10.1590/s1806-37132015000004374.
8. Mariscalco G, Debiec R, Elefteriades J, Samani N, Murphy G. Systematic Review of Studies That Have Evaluated Screening Tests in Relatives of Patients Affected by Nonsyndromic Thoracic Aortic Disease. Journal of the American Heart Association. 2018; 7: true. 10.1161/JAHA.118.009302.
9. Murillo H, Molvin L, Chin A, Fleischmann D. Aortic Dissection and Other Acute Aortic Syndromes: Diagnostic Imaging Findings from Acute to Chronic Longitudinal Progression. RadioGraphics. 2021; 41: 425 - 446. 10.1148/rg.2021200138.
10. Erbel R, Aboyans V, Boileau C, Bossone E, Bartolomeo R D et al. 2014 ESC Guidelines on the diagnosis and treatment of aortic diseases: Document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European Society of Cardiology (ESC). Eur Heart J. 2014; 35: 2873-926. 10.1093/eurheartj/ehu281.
11. Borger M A, Fedak P W M, Stephens E H, Gleason T G, Girdauskas E et al. The American Association for Thoracic Surgery consensus guidelines on bicuspid aortic valve-related aortopathy: Full online-only version. J Thorac Cardiovasc Surg. 2018; 156: e41-e74. 10.1016/j.jtcvs.2018.02.115.
12. Isselbacher E M, Preventza O, Hamilton Black J 3, Augoustides J G, Beck A W et al. 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines. Circulation. 2022; 146: e334-e482. 10.1161/CIR.0000000000001106.
13. American College of Radiology. ACR Appropriateness Criteria® Thoracic Outlet Syndrome. 2019; 2022:
14. Friedman T, Quencer K, Kishore S, Winokur R, Madoff D. Malignant Venous Obstruction: Superior Vena Cava Syndrome and Beyond. Semin Intervent Radiol. Dec 2017; 34: 398-408. 10.1055/s-0037-1608863.
15. Osiro S, Zurada A, Gielecki J, Shoja M, Tubbs R. A review of subclavian steal syndrome with clinical correlation. Med Sci Monit. May 2012; 18: Ra57-63. 10.12659/msm.882721.
16. Povlsen S, Povlsen B. Diagnosing Thoracic Outlet Syndrome: Current Approaches and Future Directions. Diagnostics (Basel). Mar 20, 2018; 8: 10.3390/diagnostics8010021.
17. Bonci G, Steigner M L, Hanley M, Braun A R, Desjardins B et al. ACR Appropriateness Criteria Thoracic Aorta Interventional Planning and Follow-Up. Journal of the American College of Radiology. 2017; 14: S570 - S583. 10.1016/j.jacr.2017.08.042.
18. Pascall E, Tulloh R. Pulmonary hypertension in congenital heart disease. Future Cardiol. Jul 2018; 14: 343-353. 10.2217/fca-2017-0065.
19. Bae S B, Kang E, Choo K S, Lee J, Kim S H et al. Aortic Arch Variants and Anomalies: Embryology, Imaging Findings, and Clinical Considerations. J Cardiovasc Imaging. 2022; 30: 231 - 262.
20. Leo I, Sabatino J, Avesani M, Moscatelli S, Bianco F et al. Non-Invasive Imaging Assessment in Patients with Aortic Coarctation: A Contemporary Review. 2024; 13: 10.3390/jcm13010028.
21. Orozco V U H M F. Thoracic Vascular Variants and Anomalies: Imaging Findings, Review of the Embryology, and Clinical Features. Indian Journal of Radiology and Imaging. 2022; 32: 568 - 575. 10.1055/s-0042-1757742.
22. Choudhury M. Postoperative management of vascular surgery patients: a brief review. Clin Surg. 2017; 2: 1584.
23. Bennett K, Kent K, Schumacher J, Greenberg C, Scarborough J. Targeting the most important complications in vascular surgery. J Vasc Surg. Mar 2017; 65: 793-803. 10.1016/j.jvs.2016.08.107.
24. Gornik H L, Persu A, Adlam D, Aparicio L S, Azizi M et al. First International Consensus on the diagnosis and management of fibromuscular dysplasia. Vascular Medicine. 2019; 24: 164 - 189. 10.1177/1358863X18821816.
25. Kesav P, Manesh Raj D, John S. Cerebrovascular Fibromuscular Dysplasia - A Practical Review. Vascular health and risk management. 2023; 19: 543-556. 10.2147/VHRM.S388257.
26. Bowen J M, Hernandez M, Johnson D S, Green C, Kammin T et al. Diagnosis and management of vascular Ehlers-Danlos syndrome: Experience of the UK national diagnostic service, Sheffield. European journal of human genetics: EJHG. 2023; 31: 749-760. 10.1038/s41431-023-01343-7.
27. Byers P. Vascular Ehlers-Danlos Syndrome. [Updated 2019 Feb 21]. GeneReviews® [Internet]. 2019.
28. Dietz H. FBN1-Related Marfan Syndrome. [Updated 2022 Feb 17]. GeneReviews® [Internet]. 2022.
29. Weinrich J M, Lenz A, Schön G, Behzadi C, Molwitz I et al. Magnetic resonance angiography derived predictors of progressive dilatation and surgery of the aortic root in Marfan syndrome. PLOS ONE. 2022; 17: true. https://doi.org/10.1371/journal.pone.0262826.
30. Loeys B, Dietz H. Loeys-Dietz Syndrome. [Updated 2018 Mar 1]. GeneReviews® [Internet]. 2018. 
31. Morris C. Williams Syndrome. [Updated 2023 Apr 13]. GeneReviews® [Internet]. 2023. 
32. Maz M, Chung S A, Abril A, Langford C A, Gorelik M et al. 2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Giant Cell Arteritis and Takayasu Arteritis. Arthritis & Rheumatology (Hoboken, N.J.). 2021; 73: 1349-1365. 10.1002/art.41774.
33. Teruzzi G, Santagostino Baldi G, Gili S, Guarnieri G, Montorsi P. Spontaneous Coronary Artery Dissections: A Systematic Review. Journal of clinical medicine. 2021; 10: 10.3390/jcm10245925.
34. Hedgire S, Saboo S, Galizia M, Aghayev A, Bolen M et al. ACR Appropriateness Criteria® Preprocedural Planning for Transcatheter Aortic. Journal of the American College of Radiology: JACR. 2023; 20: S501-S512. 10.1016/j.jacr.2023.08.009.
35. Kicska G, Hurwitz Koweek L, Ghoshhajra B, Beache G, Brown R et al. ACR Appropriateness Criteria® Suspected Acute Aortic Syndrome. Journal of the American College of Radiology: JACR. 2021; 18: S474-S481. 10.1016/j.jacr.2021.09.004.

Coding Section

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, and other nonaffiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

"Current Procedural Terminology © American Medical Association. All Rights Reserved" 

History From 2019 Forward