Description
Computed tomographic angiography (CTA) is used in the evaluation of many conditions affecting the veins and arteries of the pelvis or lower extremities. It is not appropriate as a screening tool for asymptomatic patients without a previous diagnosis.

OVERVIEW
CT/MRI and acute hemorrhage: MRI is not indicated. MRA/MRV 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 to also identify the source of acute vascular extravasation. In special cases, finer vascular detail to assess the specific vessel responsible for hemorrhage may require the use of CTA. CTA in diagnosis of lower gastrointestinal bleeding is such an example.¹⁹ MRA/MRV can be utilized in non-acute situations to assess vascular structure involved in atherosclerotic disease and its complications, such as vasculitis, venous thrombosis, vascular congestion, or tumor invasion. Although some of these conditions may be associated with hemorrhage, bleeding 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.²⁰

Follow-up of asymptomatic, incidentally detected iliac artery aneurysms: The definition of an iliac artery aneurysm (IAA) is dilatation to more than 1.5 times its normal diameter; in general, a common iliac artery ≥ 18 mm in men and ≥ 15 mm in women; an internal iliac artery (IIA) > 8 mm is considered aneurysmal.

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 months⁵

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

INDICATIONS FOR PELVIS CT Angiography / CT Venography (CTA/CTV)

IMPORTANT NOTE

When vascular imaging of the aorta and both legs, i.e., CTA aortogram and runoff is desired (sometimes incorrectly requested as Abdomen/Pelvis CTA and lower extremity CTA runoff), only one authorization request is required, using CPT Code 75635 Abdominal Arteries CTA. This study provides for imaging of the abdomen, pelvis, and both legs. The CPT code description is CTA aorto-iliofemoral runoff; abdominal aorta and bilateral ilio-femoral lower extremity runoff.

When separate requests for CTA abdomen and CTA pelvis are encountered for processes involving both the abdomen and pelvis (but do NOT need to include legs/runoff), they need to be resubmitted as a single abdomen/pelvis CTA, using CPT code 74174 (to avoid unbundling). Otherwise, the exam should be limited to the appropriate area (i.e., abdomen OR pelvis) that includes the area of concern.

Evaluation of known or suspected pelvic vascular disease
Abdominal aortic aneurysm (AAA) (needs to be resubmitted as CTA abdomen and pelvis unless there is a specific finding limited to the pelvis)

Other vascular abnormalities seen on prior imaging studies limited to the pelvis:

• 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)
• Vascular invasion or displacement by tumor (conventional CT or MRI also appropriate)¹
• For known iliac vascular disease, e.g., aneurysm, dissection, arteriovenous malformations (AVMs), and fistulas, intramural hematoma, and vasculitis^2,3,4 when ultrasound is inconclusive (See background for ultrasound screening intervals). CTA/MRA rather than CT/MRI is needed for non-aortic disease when ultrasound is inconclusive.⁵
• Suspected complications of known aneurysm as evidenced by clinical findings such as new onset of pelvic pain

Vascular ischemia or hemorrhage needs to be resubmitted as CTA Abdomen and Pelvis unless there is a specific finding limited to the pelvis)

For patients at increased risk for vascular abnormalities (CTA or MRA): (needs to be resubmitted as CTA Abdomen and Pelvis unless there is a specific finding limited to the pelvis)

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 pelvic thrombosis or thrombophlebitis)^6,7
• For unexplained lower extremity edema (typically unilateral or asymmetric) with negative or inconclusive ultrasound⁸
• For evaluation of venous thrombosis in the inferior vena cava⁹
• Venous thrombosis if previous studies have not resulted in a clear diagnosis¹⁰
• Vascular invasion or displacement by tumor (Conventional CT or MRI also appropriate)^1,11
• For suspected May-Thurner Syndrome (iliac vein compression syndrome) (can include abdomen CTA)^12,13

Other vascular indications

• For evaluation of erectile dysfunction when a vascular cause is suspected and Doppler ultrasound is inconclusive¹⁴

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)

Pre-operative evaluation^15,16

• Evaluation of interventional vascular procedures prior to endovascular aneurysm repair (EVAR), or for luminal patency versus restenosis due to conditions such as atherosclerosis, thromboembolism, and intimal hyperplasia
• Imaging of the deep inferior epigastric arteries for surgical planning (breast reconstruction surgery), if abdomen CTA is also needed, resubmit as abdomen and pelvis CTA¹⁶
• Prior to uterine artery embolization for fibroids (MRA preferred)¹⁷
• Prior to solid organ transplantation when vascular anatomy is needed

Post-operative or post-procedural evaluation

• Evaluation of post-operative complications of renal transplant allograft¹⁸
• Evaluation of endovascular/interventional 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 the pelvis
• Follow-up for post-endovascular repair (EVAR) or open repair of abdominal aortic aneurysm (AAA)⁵ or abdominal extent of iliac artery aneurysms. CT preferred unless MRA/CTA is needed for procedural planning or to evaluate complex anatomy.(Needs to be resubmitted as CTA abdomen and pelvis unless there is a specific finding limited to the pelvis)

When pelvis CTA is requested in combination with chest CTA, the pelvis CTA needs to be resubmitted as an abdomen/pelvis CTA (see Abdomen/Pelvis CTA Guidelines for approvable combo indications).

All other uses of this technology are investigational and/or unproven and therefore considered NOT MEDICALLY NECESSARY.

References 

15. American College of Radiology. ACR Appropriateness Criteria® Abdominal Aortic Aneurysm: Interventional Planning and Follow-up. American College of Radiology. Updated 2017. Accessed November 16, 2022. https://acsearch.acr.org/docs/70548/Narrative/
16. 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/
17. 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
18. 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
19. 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
20. 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

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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