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.

Policy:
IMPORTANT NOTE: Abdomen/Pelvis Magnetic Resonance Angiography (MRA) with Lower Extremity MRA Runoff Requests: Two authorization requests are required, one Abdomen MRA, CPT code 74185 and one for Lower Extremity MRA, CPT code 73725 (a separate Pelvic MRA request is not required). This will provide imaging of the abdomen, pelvis, and both legs. 

INDICATIONS FOR PELVIS MR ANGIOGRAPHY/MR VENOGRAPHY (MRA/MRV) 

Arterial

Evaluation of known or suspected pelvic vascular disease 
Abdominal Aortic Aneurysm (AAA) (also approve Abdomen MRA):

• For asymptomatic known or suspected abdominal aortic aneurysms, ultrasound should be done prior to advanced imaging. Only when the ultrasound is inconclusive, is advanced imaging with CT or MRI needed.
• For symptomatic known or suspected AAA (such as recent-onset abdominal pain or back pain, particularly in the presence of a pulsatile or epigastric mass, suspected dissection, or significant risk factors for AAA) CTA/MRA is appropriate and generally preferred over CT/MRI. (If contrast is contraindicated or other clinical indications for abdomen and/or pelvic imaging are present, then CT/MR may be approved rather than CTA/MRA).
• If there is known complex vascular anatomy, CTA/MRA may be needed.

Other vascular abnormalities seen on prior imaging studies:

• Initial evaluation of inconclusive vascular findings on prior imaging
• Follow-up of known visceral vascular conditions in the pelvis (such as aneurysm, dissection, compression syndromes, arteriovenous malformations (AVMs), fistulas, intramural hematoma, and vasculitis) 
• For assessment in patients with spontaneous coronary artery dissection (SCAD), can be done at time of coronary angiography (also approve MRA abdomen)¹ 
• Vascular invasion or displacement by tumor (conventional CT or MRI also appropriate)² 
• For known large vessel diseases (inferior vena cava or iliac arteries/veins), e.g., aneurysm/dissection (non-aortic disease), arteriovenous malformations (AVMs), and fistulas, intramural hematoma, and vasculitis^3-5
  • Surveillance is done with ultrasound at intervals similar to AAA, however, CTA/MRA rather than CT/MRI is needed for non-aortic disease when ultrasound is inconclusive⁶ 
• Follow-up of iliac artery aneurysm when ultrasound is inconclusive and CI to CTA is provided (see Background) 
• Suspected complications of known aneurysm as evidenced by clinical findings such as new onset of pelvic pain

Vascular ischemia or hemorrhage: 

• To determine the vascular source of retroperitoneal hematoma or hemorrhage when CT is insufficient to determine the source and CTA is contraindicated (may also approve Abdomen MRA; CT rather than MRA/CTA is the modality of choice for diagnosing hemorrhage)⁷
• For evaluation of known or suspected mesenteric ischemia/ischemic colitis when CTA is contraindicated (can approve MRA abdomen and pelvis)⁸ 

For patients at increased risk for vascular abnormalities (CTA or MRA):

• For patients with fibromuscular dysplasia (FMD), a one-time vascular study of the abdomen and pelvis⁹ 
• For patients with vascular Ehlers-Danlos syndrome or Marfan syndrome, a one-time vascular study of the abdomen and pelvis 
• For Loeys-Dietz, imaging at diagnosis and then every two years, more frequently if abnormalities are found (Imaging may include head, neck, chest, abdomen and pelvis)^10,11 

Venous

• For evaluation of suspected pelvic vascular disease or pelvic congestive syndrome when findings on ultrasound are indeterminate (MR or CT venography (CTV) may be used as the initial study for evaluating pelvic thrombosis or thrombophlebitis)^{12, 13}
• For unexplained lower extremity edema (typically unilateral or asymmetric) with negative or inconclusive ultrasound¹⁴
• For evaluation of venous thrombus in the inferior vena cava¹⁵
• Venous thrombosis if previous studies have not resulted in a clear diagnosis¹⁶
• Vascular invasion or displacement by tumor (Conventional CT or MRI also appropriate)²
• For known/suspected May-Thurner Syndrome (iliac vein compression syndrome)^{17, 18}

Pre-operative evaluation^19-21

• Evaluation prior to interventional vascular for luminal patency versus restenosis due to conditions such as atherosclerosis, thromboembolism, and intimal hyperplasia
• Evaluation prior to endovascular aneurysm repair (EVAR)
• Imaging of the deep inferior epigastric arteries for surgical planning (breast reconstruction surgery) include CTA/MRA abdomen
• Prior to uterine artery embolization for fibroids²²
• Prior to solid organ transplantation when vascular anatomy is needed

Post-operative or post-procedural evaluation 

• Post-operative complications of renal transplant allograft²³
• Endovascular/interventional vascular procedures for luminal patency versus restenosis due to conditions such as atherosclerosis, thromboembolism, and intimal hyperplasia
• Post-operative complications, e.g., pseudoaneurysms related to surgical bypass grafts, vascular stents, and stent-grafts in the pelvis
• Follow-up for post-endovascular repair (EVAR) or open repair of abdominal aortic aneurysm (AAA)²⁴ or abdominal extent of iliac artery aneurysms (CT preferred  unless MRA/CTA is needed for procedural planning or to evaluate complex anatomy)
  • Routine, baseline study (post-op/intervention) is warranted within the first month after EVAR:
  • Repeat in 6 months if type II endoleak is seen (continue every 6 months x 24 months, then annually)
  • Repeat in 12 months if no endoleak or sac enlargement is seen
  • If neither endoleak nor AAA enlargement is seen on imaging one year after EVAR, CT is needed only if US is inconclusive for annual surveillance (until year 5 as below)
  • Non-contrast CT of entire aorta (abdomen and pelvis) is needed every 5 years after open repair of AAA or EVAR
  • If symptomatic or imaging shows increasing, or new findings related to stent graft — more frequent imaging may be needed
  • For suspected complication such as: new-onset lower extremity claudication, ischemia, or reduction in ABI after aneurysm repair
• 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. 

Other Indications
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)

Chest MRA, Abdomen MRA, or Abdomen/Pelvis MRA combo

• Acute aortic dissection (CTA or CT preferred)
• Takayasu’s arteritis
• Marfan syndrome
• Loeys-Dietz syndrome
• Spontaneous coronary artery dissection (SCAD)
• Vascular Ehlers-Danlos syndrome
• Post-operative complications
• Significant post-traumatic or post-procedural vascular complications reasonably expected to involve the chest and/or abdomen and/or pelvis

Rationale
Magnetic resonance angiography (MRA) generates images of the arteries that can be evaluated for evidence of stenosis, occlusion, or aneurysms. It is used to evaluate the arteries of the abdominal aorta and the renal arteries. Contrast-enhanced MRA requires the injection of a contrast agent which results in very high-quality images. It does not use ionizing radiation, allowing MRA to be used for follow-up evaluations. 

OVERVIEW
Bruits: Blowing vascular sounds heard over partially occluded blood vessels. Abdominal bruits may indicate partial obstruction of the aorta or other major arteries such as the renal, iliac, or femoral arteries. Associated risks include but are not limited to; renal artery stenosis, aortic aneurysm, atherosclerosis, AVM, or coarctation of aorta.

MRA and Chronic Mesenteric Ischemia — Contrast-enhanced MRA is used for the evaluation of chronic mesenteric ischemia, including treatment follow-up. Chronic mesenteric ischemia is usually caused by severe atherosclerotic disease of the mesenteric arteries, e.g., celiac axis, superior mesenteric artery, inferior mesenteric artery. At least two of the arteries are usually affected before the occurrence of symptoms such as abdominal pain after meals and weight loss. MRA is the technique of choice for the evaluation of chronic mesenteric ischemia in patients with impaired renal function.

MRA and Abdominal Aortic Aneurysm Repair — MRA may be performed before endovascular repair of an abdominal aortic aneurysm. Endovascular repair of abdominal aortic aneurysm is a minimally invasive alternative to open surgical repair, and its success depends on precise measurement of the dimensions of the aneurysm and vessels. This helps to determine selection of an appropriate stent-graft diameter and length to minimize complications, such as endoleakage. MRA provides images of the aorta and branches in multiple 3D projections and may help to determine the dimensions needed for placement of an endovascular aortic stent graft. MRA is noninvasive and rapid and may be used in patients with renal impairment. 

Iliac aneurysm ultrasound screening intervals:

• Aneurysm size 2.0 – 2.9 cm, every 3 years
• Aneurysm size 3.0 – 3.4 cm, annually
• Aneurysm size > 3.5 cm, every 6 months

MRI/CT and acute hemorrhage: MRI is not indicated and MRA/MRV (MR Angiography/Venography) is rarely indicated for evaluation of intraperitoneal or retroperitoneal 
hemorrhage, particularly in the acute setting. CT is the study of choice due to its availability, speed of the study, and less susceptibility to artifact from patient motion. Advances in technology have allowed conventional CT to not just detect hematomas but also the source of acute vascular extravasation. In special cases, finer vascular detail to assess the specific source vessel responsible for hemorrhage may require the use of CTA. CTA in the diagnosis of lower gastrointestinal bleeding is such an example.²⁵

MRA/MRV is often utilized in non-acute situations to assess vascular structure involved in atherosclerotic disease and its complications, vasculitis, venous thrombosis, vascular congestion, or tumor invasion. Although some of these conditions may be associated with hemorrhage, it is usually not the primary reason why MRI/MRA/MRV is selected for the evaluation. A special condition where MRI may be superior to CT for evaluating hemorrhage is to detect an underlying neoplasm as the cause of bleeding.⁷

References 

1. Crousillat DR, Wood MJ. Spontaneous Coronary Artery Dissection: An Update for the Interventionalist. HMP Global Learning Network. Updated March 2020. Accessed December 28, 2022, 2022. https://www.hmpgloballearningnetwork.com/site/cathlab/content/spontaneous-coronary-artery-dissection-update-interventionalist
2. Čertík B, Třeška V, Moláček J, Šulc R. How to proceed in the case of a tumour thrombus in the inferior vena cava with renal cell carcinoma. Cor et Vasa. 2015/04/01/ 2015;57(2):e95-e100. doi:https://doi.org/10.1016/j.crvasa.2015.02.015
3. Thakur V, Inampudi P, Pena CS. Imaging of mesenteric ischemia. Applied Radiol 2018;47(2):13-18. 
4. Harvin HJ, Verma N, Nikolaidis P, et al. ACR Appropriateness Criteria(®) Renovascular Hypertension. J Am Coll Radiol. Nov 2017;14(11s):S540-s549.  doi:10.1016/j.jacr.2017.08.040
5. American College of Radiology. ACR Appropriateness Criteria® Noncerebral Vasculitis. American College of Radiology (ACR). Updated 2021. Accessed November 20, 2022. https://acsearch.acr.org/docs/3158180/Narrative/
6. Wanhainen A, Verzini F, Van Herzeele I, et al. Editor's Choice - European Society for Vascular Surgery (ESVS) 2019 Clinical Practice Guidelines on the Management of Abdominal Aorto-iliac Artery Aneurysms. Eur J Vasc Endovasc Surg. Jan 2019;57(1):8-93. doi:10.1016/j.ejvs.2018.09.020
7. Abe T, Kai M, Miyoshi O, Nagaie T. Idiopathic Retroperitoneal Hematoma. Case Rep Gastroenterol. Sep 11 2010;4(3):318-322. doi:10.1159/000320590
8. American College of Radiology. ACR Appropriateness Criteria® Imaging of Mesenteric Ischemia. American College of Radiology. Updated 2018. Accessed November 19, 2022. https://acsearch.acr.org/docs/70909/Narrative/
9. Kadian-Dodov D, Gornik HL, Gu X, et al. Dissection and Aneurysm in Patients With Fibromuscular Dysplasia: Findings From the U.S. Registry for FMD. J Am Coll Cardiol. Jul 12 2016;68(2):176-85. doi:10.1016/j.jacc.2016.04.044
10. Chu LC, Johnson PT, Dietz HC, Fishman EK. CT angiographic evaluation of genetic vascular disease: role in detection, staging, and management of complex vascular pathologic conditions. AJR Am J Roentgenol. May 2014;202(5):1120-9. doi:10.2214/ajr.13.11485
11. MacCarrick G, Black JH, 3rd, Bowdin S, et al. Loeys-Dietz syndrome: a primer for diagnosis and management. Genet Med. Aug 2014;16(8):576-87. doi:10.1038/gim.2014.11
12. Bookwalter CA, VanBuren WM, Neisen MJ, Bjarnason H. Imaging Appearance and Nonsurgical Management of Pelvic Venous Congestion Syndrome. Radiographics. Mar-Apr 2019;39(2):596-608. doi:10.1148/rg.2019180159
13. Knuttinen MG, Xie K, Jani A, Palumbo A, Carrillo T, Mar W. Pelvic venous insufficiency: imaging diagnosis, treatment approaches, and therapeutic issues. AJR Am J Roentgenol. Feb 2015;204(2):448-58. doi:10.2214/ajr.14.12709
14. Hoshino Y, Machida M, Shimano Si, et al. Unilateral Leg Swelling: Differential Diagnostic Issue Other than Deep Vein Thrombosis. Journal of General and Family Medicine. 2016;17(4):311-314. 
15. Aw-Zoretic J, Collins JD. Considerations for Imaging the Inferior Vena Cava (IVC) with/without IVC Filters. Semin Intervent Radiol. Jun 2016;33(2):109-21. doi:10.1055/s-0036-1583207
16. American College of Radiology. ACR Appropriateness Criteria® Suspected Lower Extremity Deep Vein Thrombosis. American College of Radiology. Updated 2018. Accessed January 23, 2023. https://acsearch.acr.org/docs/69416/Narrative/
17. Kalu S, Shah P, Natarajan A, Nwankwo N, Mustafa U, Hussain N. May-thurner syndrome: a case report and review of the literature. Case Rep Vasc Med. 2013;2013:740182. doi:10.1155/2013/740182
18. Shammas NW, Jones-Miller S, Kovach T, et al. Predicting Significant Iliac Vein Compression Using a Probability Scoring System Derived From Minimal Luminal Area on Computed Tomography Angiography in Patients 65 Years of Age or Younger. J Invasive Cardiol. Jan 2021;33(1):E16-e18. 
19. American College of Radiology. ACR Appropriateness Criteria® Imaging for Transcatheter Aortic Valve Replacement. American College of Radiology. Updated 2017. Accessed November 16, 2022. https://acsearch.acr.org/docs/3082594/Narrative/
20. American College of Radiology. ACR Appropriateness Criteria® Imaging of Deep Inferior Epigastric Arteries for Surgical Planning (Breast Reconstruction Surgery). American College of Radiology. Updated 2022. Accessed November 16, 2022. https://acsearch.acr.org/docs/3101591/Narrative/
21. American College of Radiology. ACR Appropriateness Criteria® Abdominal Aortic Aneurysm: Interventional Planning and Follow-up. American College of Radiology. Updated 2017. Accessed December 28, 2022. https://acsearch.acr.org/docs/70548/Narrative/
22. Maciel C, Tang YZ, Sahdev A, Madureira AM, Vilares Morgado P. Preprocedural MRI and MRA in planning fibroid embolization. Diagn Interv Radiol. Mar-Apr 2017;23(2):163-171. doi:10.5152/dir.2016.16623
23. Bultman EM, Klaers J, Johnson KM, et al. Non-contrast enhanced 3D SSFP MRA of the renal allograft vasculature: a comparison between radial linear combination and Cartesian inflow-weighted acquisitions. Magn Reson Imaging. Feb 2014;32(2):190-5. doi:10.1016/j.mri.2013.10.004
24. Chaikof EL, Dalman RL, Eskandari MK, et al. The Society for Vascular Surgery practice guidelines on the care of patients with an abdominal aortic aneurysm. J Vasc Surg. Jan 2018;67(1):2-77.e2. doi:10.1016/j.jvs.2017.10.044
25. Clerc D, Grass F, Schäfer M, Denys A, Demartines N, Hübner M. Lower gastrointestinal bleeding-Computed Tomographic Angiography, Colonoscopy or both? World J Emerg Surg. 2017;12:1. doi:10.1186/s13017-016-0112-3

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, Blue Cross Blue Shield Association technology assessment program (TEC) 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" 

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