CT Lower Extremity (Ankle, Foot, Hip or Knee) - CAM 715HB

Plain radiographs are typically used as the first-line modality for assessment of lower extremity conditions. Computed tomography (CT) is used for evaluation of tumors, metastatic lesions, infection, fractures, and other problems. Magnetic resonance imaging (MRI) is the first-line choice for imaging of many conditions, but CT may be used in these cases if MRI is contraindicated or unable to be performed

*Conservative therapy — (Musculoskeletal) should include a multimodality approach consisting of a combination of active and inactive components. Inactive components such as rest, ice, heat, modified activities, medical devices (such as crutches, immobilizer, metal braces, orthotics, rigid stabilizer, or splints, etc. and not to include neoprene sleeves), medications, injections (bursal, and/or joint, not including trigger point), and diathermy, can be utilized.

Active modalities may consist of physical therapy, a physician-supervised home exercise program**, and/or chiropractic care.

**Home exercise program (HEP) — The following two elements are required to meet guidelines for completion of conservative therapy:

  • Information provided on exercise prescription/plan AND
  • Follow up with member with information provided regarding completion of HEP (after suitable 4-week period), or inability to complete HEP due to physical reason, i.e., increased pain, inability to physically perform exercises. (Patient inconvenience or noncompliance without explanation does not constitute “inability to complete” HEP).

Joint implants and hardware — Dual-energy CT may be useful for metal artifact reduction if available but is also imperfect as the correction is based on a projected approximation of X-ray absorption, and it does not correct for scatter.74 Dual-energy CT can be used to characterize crystal deposition disease, such as gout versus CPPD (calcium pyrophosphate deposition).61

CT and osteolysis — Since computed tomography scans show both the extent and the location of lytic lesions, they are useful to guide treatment decisions, as well as to assist in planning for surgical intervention when needed, in patients with suspected osteolysis after total hip arthroplasty (THA).

American Academy of Pediatrics “Choosing Wisely” Guidelines advise against ordering advanced imaging studies (MRI or CT) for most musculoskeletal conditions in a child until all appropriate clinical, laboratory and plain radiographic examinations have been completed. “History, physical examination, and appropriate radiographs remain the primary diagnostic modalities in pediatric orthopedics, as they are both diagnostic and prognostic for the great majority of pediatric musculoskeletal conditions. Examples of such conditions would include, but not be limited to, the work up of injury or pain (spine, knees and ankles), possible infection, and deformity. MRI examinations and other advanced imaging studies frequently require sedation in the young child (5 years old or less) and may not result in appropriate interpretation if clinical correlations cannot be made. Many conditions require specific MRI sequences or protocols best ordered by the specialist who will be treating the patient … if you believe findings warrant additional advanced imaging, discuss with the consulting orthopedic surgeon to make sure the optimal studies are ordered.”75


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.

(Plain radiographs must precede CT evaluation.)

Some indications are for MRI, CT, or MR or CT arthrogram. More than one should not be approved at the same time.

If a CT arthrogram fits approvable criteria below, approve as CT.

Joint or muscle pain without positive findings on an orthopedic exam as listed below and after X-ray completed1,2,3 (does not apply to young children). If MRI contraindicated or cannot be performed or requested as a CT arthrogram:

  • Persistent joint or musculotendinous pain unresponsive to conservative treatment*, within the last 6 months which includes active medical therapy (physical therapy, chiropractic treatments, and/or physician supervised exercise**) of at least four (4) weeks, OR
  • With progression or worsening of symptoms during the course of conservative treatment

Joint specific approvable provocative orthopedic examination tests and suspected injuries4 (If MRI contraindicated or cannot be performed or requested as a CT arthrogram).
Note: With a positive orthopedic sign, an initial x-ray is always preferred, however, it is not required to approve advanced imaging UNLESS otherwise specified in bold below. Any test that suggests joint instability requires further imaging (list is not all inconclusive)


  • Syndesmotic injury (high ankle injury) with tenderness to palpation over the syndesmosis (AITFL — anterior inferior tibiofibular ligament) and any of the following:
    • Positive stress X-rays
    • Squeeze test
    • Cotton test
    • Dorsiflexion external rotation test.
  • Unstable lateral injury to ATFL (anterior talofibular ligament) with suspicion of a possible associated fracture around the ankle or a possible osteochondral injury of the talus AFTER non-diagnostic or inconclusive X-rays and any ONE of the following:
    • Positive stress X-rays
    • Positive anterior drawer test
    • Positive posterior drawer test
  • Achilles tendon tear
    • Thompson test


  • Anterior cruciate ligament (ACL) Injury
  • Positive testing:
    • Anterior drawer
    • Lachman’s
    • Pivot shift test


  • Suspected ACL Rupture — Acute knee injury with physical exam limited by pain and swelling AFTER initial X-ray completed13,14
    • Based on mechanism of injury, i.e., twisting, blunt force
      • Normal X-ray:
        • Extreme pain, inability to stand, audible pop at time of injury, very swollen joint
      • Abnormal X-ray:
        • Large joint effusion on X-ray knee effusion
  • Acute mechanical locking of the knee not due to guarding15
  • Meniscal injury/tear (A positive test is denoted by pain or audible/palpable clunk)
    • McMurray’s Compression
    • Apley’s
    • Thessaly test
  • Patellar dislocation (acute or recurrent)
    • Positive patellofemoral apprehension test
    • Radiographic findings compatible with a history of patellar dislocation (i.e., lipohemarthrosis or osteochondral fracture)
  • Posterior cruciate ligament (PCL) injury
    • Posterior drawer
    • Posterior tibial sag (Godfrey or step-off test)
  • Medial collateral ligament tear
    • Positive valgus stress testing/laxity
  • Lateral Collateral ligament tear
    • Positive Varus stress testing/laxity 


  • Femoroacetabular impingement (FAI)/ Labral tear
    • Anterior Impingement sign (aka FADIR test)16,17,18
    • Posterior Impingement sign (Pain with hip extension and external rotation on exam)19
    • Persistent hip mechanical symptoms (after initial radiographs completed) including clicking, locking, catching, giving way or hip instability with a clinical suspicion of labral tear and/or radiographic findings suggestive of FAI (i.e., cross over sign/pistol grip deformity) and suspected labral tear
    • To determine candidacy for hip preservation surgery for known FAI20

NOTE: For evaluation of both hips when the patient meets hip MRI guidelines (X-ray + persistent pain unresponsive to conservative treatment) for both the right and left hip, Pelvis MRI (NIA_CG_037) is the preferred study:

  • If labral tear is suspected and fulfills above criteria, then bilateral hip MRIs are the preferred studies (not pelvis MRI)
  • If bilateral hip arthrograms are requested and otherwise meet guidelines, bilateral hip MRIs are the preferred studies (not pelvis MRI)

Tendon rupture after X-ray21,22,23,24 (not listed in above) — If MRI contraindicated or cannot be performed:

  • High clinical suspicion of specific tendon rupture based on mechanism of injury and physical findings (i.e., palpable defect in quadriceps or patellar tendon rupture)

Bone Fracture (If MRI contraindicated or cannot be performed)

  • Hip and femur
    • Suspected occult, stress or insufficiency fracture with a negative or non- diagnostic initial X-ray:25
      • Approve an immediate CT if contraindication to MRI or MRI cannot be performed (no follow up radiographs required)
  • Non-hip extremities: suspected occult, stress, or insufficiency fracture
    • If X-rays, taken 10 – 14 days after the injury or clinical assessment, are negative or nondiagnostic26
    • If at high risk for a complete fracture with conservative therapy (e.g., navicular bone), then immediate CT is warranted27
  • Pathologic or concern for impending fracture on X-ray28 — approve immediate CT
  • Suspected ligamentous/tendon injury with known fractures on x-ray that may require surgery

Fracture Nonunion

  • Nonunion or delayed union as demonstrated by no healing between two sets of X-rays. If a fracture has not healed by 4 – 6 months, there is delayed union. Incomplete healing by 6 – 8 months is nonunion.

Osteochondral Lesions (defects, fractures, osteochondritis dissecans) and X-ray done:8,29,30,31,32

  • Clinical suspicion based on mechanism of injury and physical findings

Joint Prosthesis/Replacement

  • Suspected joint prosthesis loosening or dysfunction, (i.e. pseudotumor formation) after initial X-rays33,34
  • Suspected metallosis with painful metal on metal hip replacement after initial X-rays
    • After initial X-rays and Cobalt - chromium levels > 7ppb35
    • Abnormal joint aspiration

Extremity Mass

  • Mass or lesion after non-diagnostic X-ray or ultrasound.36 MRI preferred. CT is better than MRI to evaluate mass calcification or bone involvement and may complement or replace MRI:37
    • Baker’s cyst should be initially evaluated with ultrasound
    • If superficial, then ultrasound is the initial study
    • If deep, then X-ray is the initial study
  • Vascular malformations
    • After initial evaluation with ultrasound and results will change management or for preoperative planning38
      • CTA is also approvable for initial evaluation
    • Follow up after treatment/embolization

Known Primary Cancer of the Extremity39,40,41,42,43

  • Initial staging primary extremity tumor
  • Follow-up of known primary cancer of patient undergoing active treatment within the past year or as per surveillance imaging guidance for that cancer
  • Signs or symptoms or imaging findings suspicious for recurrence
  • Suspected metastatic disease with signs/symptoms and after initial imaging with radiographs

Further evaluation of indeterminate or questionable findings on prior imaging and MRI cannot be performed or CT is preferred (i.e., tumor matrix):

  • For initial evaluation of an inconclusive finding on a prior imaging report (i.e., X-ray, ultrasound, MRI) 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

Osteonecrosis (avascular necrosis [AVN], Legg-Calve-Perthes Disease) when MRI is contraindicated or cannot be performed:44,45,46

  • To further characterize a prior abnormal X-ray
  • Normal or indeterminate X-rays but symptomatic and high risk (e.g., glucocorticosteroid use, renal transplant recipient, glycogen storage disease, alcohol abuse,47 sickle cell anemia48)
  • Known osteonecrosis to evaluate a contralateral joint after initial X-rays

Loose bodies or synovial chondromatosis and after X-ray or ultrasound completed (If MRI contraindicated or cannot be completed)

  • In the setting of joint pain or mechanical symptoms49

Infection of Bone, Joint, or Soft Tissue Abscess50,51
Note: MRI and nuclear medicine studies are recommended for acute infection as they are more sensitive in detecting early changes of osteomyelitis.52,53 CT is better at demonstrating findings of chronic osteomyelitis (sequestra, involucrum, cloaca, sinus tracts) as well as detecting soft tissue gas and foreign bodies.54

  • Abnormal X-ray or ultrasound
  • Negative X-ray but with a clinical suspicion of infection
    • Signs and symptoms of joint or bone infection include:
      • Pain and swelling
      • Decrease range of motion
      • Fevers
    • Laboratory findings of infection include any of the following:
      • Elevated ESR or CRP
      • Elevated white blood cell count
      • Positive joint aspiration
  • Ulcer (diabetic, pressure, ischemic, traumatic) with signs of infection (redness, warm, swelling, pain, discharge which may range from white to serosanguineous) that is not improving despite treatment and bone or deep infection is suspected55
    • Increased suspicion if size or temperature increases, bone is exposed/positive probe-to-bone test, new areas of breakdown, new smell56
  • Neuropathic foot with friable or discolored granulation tissue, foul odor, non-purulent discharge, and delayed wound healing57

Pre-operative/procedural evaluation

  • Pre-operative evaluation for a planned surgery or procedure

Post-operative/procedural evaluation

  • When imaging, physical, or laboratory findings indicate joint infection, delayed or non- healing, or other surgical/procedural complications
  • Trendelenburg sign or other indication of muscle or nerve damage after recent hip surgery

For evaluation of known or suspected autoimmune disease (e.g., rheumatoid arthritis) and MRI is contraindicated or cannot be performed58

  • Further evaluation of an abnormality or non-diagnostic findings on prior imaging
  • Initial imaging of a single joint for diagnosis or response to therapy after plain films and appropriate lab tests (e.g., RF, ANA, CRP, ESR)
  • To determine change in treatment or when diagnosis is uncertain prior to start of treatment
  • Follow-up to determine treatment efficacy of the following:
    • Early rheumatoid arthritis
    • Advanced rheumatoid arthritis if X-ray and ultrasound are equivocal or non- contributory

Known or suspected inflammatory myopathies (If MRI contraindicated or cannot be performed): (Includes polymyositis, dermatomyositis, immune-mediated necrotizing myopathy, inclusion body myositis)59,60

  • For diagnosis
  • For biopsy planning

Crystalline Arthropathy 

  • Dual-energy CT can be used to characterize crystal deposition disease (i.e., gout) after
    • Appropriate rheumatological work up and initial X-rays AND
    • After inconclusive joint aspiration or when joint aspiration cannot be performed OR61
    • In the setting of extra-articular crystal deposits (i.e., tendons or bursa)

Peripheral Nerve Entrapment (e.g., tarsal tunnel, Morton’s neuroma) and MRI is contraindicated or cannot be performed, including any of the following62,63,64,65

  • Abnormal electromyogram or nerve conduction study
  • Abnormal X-ray or ultrasound
  • Clinical suspicion and failed 4 weeks conservative treatment including at least 2 of the following (active treatment with physical therapy is not required):
    • Activity modification
    • Rest, ice, or heat
    • Splinting or orthotics
    • Medication

Leg length discrepancy

  • CT scanogram66,67

Foreign Body68

  • Indeterminate X-ray and ultrasound

Painful acquired or congenital flatfoot deformity in an adult, after X-ray completed and MRI is contraindicated or cannot be performed.

  • After failure of active conservative therapy listed above69,70


  • Osteoid Osteoma after an X-ray is done71
  • Painful flatfoot (pes planus) deformity with suspected tarsal coalition, not responsive to active conservative care72
    • When MRI cannot be performed
    • Extra-articular coalition is suspected (bony bridges around the joints)
    • When needed for surgical planning73


  1. Katz JN, Brophy RH, Chaisson CE, et al. Surgery versus physical therapy for a meniscal tear and osteoarthritis. N Engl J Med. May 2 2013;368(18):1675-84. doi:10.1056/NEJMoa1301408
  2. Mordecai SC, Al-Hadithy N, Ware HE, Gupte CM. Treatment of meniscal tears: An evidence based approach. World J Orthop. Jul 18 2014;5(3):233-41. doi:10.5312/wjo.v5.i3.233
  3. American College of Radiology. ACR Appropriateness Criteria® Chronic Foot Pain. American College of Radiology (ACR). Updated 2020. Accessed Janaury 23, 2023. https://acsearch.acr.org/docs/69424/Narrative/
  4. Fox MG, Chang EY, Amini B, et al. ACR Appropriateness Criteria(®) Chronic Knee Pain. J Am Coll Radiol. Nov 2018;15(11s):S302-s312. doi:10.1016/j.jacr.2018.09.016
  5. Chen ET, Borg-Stein J, McInnis KC. Ankle Sprains: Evaluation, Rehabilitation, and Prevention. Curr Sports Med Rep. Jun 2019;18(6):217-223. doi:10.1249/jsr.0000000000000603
  6. Scillia AJ, Pierce TP, Issa K, et al. Low Ankle Sprains: A Current Review of Diagnosis and Treatment. Surg Technol Int. Jul 25 2017;30:411-414.
  7. Petersen W, Rembitzki IV, Koppenburg AG, et al. Treatment of acute ankle ligament injuries: a systematic review. Arch Orthop Trauma Surg. Aug 2013;133(8):1129-41. doi:10.1007/s00402- 013-1742-5
  8. American College of Radiology. ACR Appropriateness Criteria® Acute Trauma to the Knee. American College of Radiology (ACR). Updated 2019. Accessed January 23, 2023. https://acsearch.acr.org/docs/69419/Narrative/
  9. Doral MN, Bilge O, Huri G, Turhan E, Verdonk R. Modern treatment of meniscal tears. EFORT Open Rev. May 2018;3(5):260-268. doi:10.1302/2058-5241.3.170067
  10. Mohankumar R, White LM, Naraghi A. Pitfalls and pearls in MRI of the knee. AJR Am J Roentgenol. Sep 2014;203(3):516-30. doi:10.2214/ajr.14.12969
  11. Smith BE, Thacker D, Crewesmith A, Hall M. Special tests for assessing meniscal tears within the knee: a systematic review and meta-analysis. Evid Based Med. Jun 2015;20(3):88-97. doi:10.1136/ebmed-2014-110160
  12. Smoak JB, Matthews JR, Vinod AV, Kluczynski MA, Bisson LJ. An Up-to-Date Review of the Meniscus Literature: A Systematic Summary of Systematic Reviews and Meta-analyses. Orthop J Sports Med. Sep 2020;8(9):2325967120950306. doi:10.1177/2325967120950306
  13. Cecava ND, Dieckman S, Banks KP, Mansfield LT. Traumatic knee injury: correlation of radiographic effusion size with the presence of internal derangement on magnetic resonance imaging. Emerg Radiol. Oct 2018;25(5):479-487. doi:10.1007/s10140-018-1605-z
  14. Wheeless CR, Nunley JA, Urbaniak JR, Duke University Medical Center's Division of Orthopedic Surgery, . Wheeless' textbook of orthopaedics. Data Trace Internet Publishing, LLC; 2016. Updated 2018. http://www.wheelessonline.com/
  15. Hussin P, Mawardi M, Nizlan NM. The 'Chalky Culprit' of acute locked knee. G Chir. Sep-Oct 2014;35(9-10):239-40.
  16. Hananouchi T, Yasui Y, Yamamoto K, Toritsuka Y, Ohzono K. Anterior impingement test for labral lesions has high positive predictive value. Clin Orthop Relat Res. Dec 2012;470(12):3524-9. doi:10.1007/s11999-012-2450-0
  17. Naraghi A, White LM. MRI of Labral and Chondral Lesions of the Hip. AJR Am J Roentgenol. Sep 2015;205(3):479-90. doi:10.2214/ajr.14.12581
  18. American College of Radiology. ACR Appropriateness Criteria® Acute Hip Pain-Suspected Fracture. American College of Radiology. Updated 2018. Accessed Janaury 23, 2023. https://acsearch.acr.org/docs/3082587/Narrative/
  19. Groh MM, Herrera J. A comprehensive review of hip labral tears. Curr Rev Musculoskelet Med. Jun 2009;2(2):105-17. doi:10.1007/s12178-009-9052-9
  20. Li AE, Jawetz ST, Greditzer HGt, Burge AJ, Nawabi DH, Potter HG. MRI for the preoperative evaluation of femoroacetabular impingement. Insights Imaging. Apr 2016;7(2):187-98. doi:10.1007/s13244-015-0459-0
  21. Wilkins R, Bisson LJ. Operative versus nonoperative management of acute Achilles tendon ruptures: a quantitative systematic review of randomized controlled trials. Am J Sports Med. Sep 2012;40(9):2154-60. doi:10.1177/0363546512453293
  22. Rubin DA. Imaging diagnosis and prognostication of hamstring injuries. AJR Am J Roentgenol. Sep 2012;199(3):525-33. doi:10.2214/ajr.12.8784
  23. Peck J, Gustafson K, Bahner D. Diagnosis of Achilles tendon rupture with ultrasound in the emergency department setting. Images in Academic Medicine: Republication. International Journal of Academic Medicine. May 1, 2017 2017;3(3):205-207. doi:10.4103/ijam.Ijam_16_17
  24. Garras DN, Raikin SM, Bhat SB, Taweel N, Karanjia H. MRI is unnecessary for diagnosing acute Achilles tendon ruptures: clinical diagnostic criteria. Clin Orthop Relat Res. Aug 2012;470(8):2268-73. doi:10.1007/s11999-012-2355-y
  25. Bencardino JT, Stone TJ, Roberts CC, et al. ACR Appropriateness Criteria(®) Stress (Fatigue/Insufficiency) Fracture, Including Sacrum, Excluding Other Vertebrae. J Am Coll Radiol. May 2017;14(5s):S293-s306. doi:10.1016/j.jacr.2017.02.035
  26. Uthgenannt BA, Kramer MH, Hwu JA, Wopenka B, Silva MJ. Skeletal self-repair: stress fracture healing by rapid formation and densification of woven bone. J Bone Miner Res. Oct 2007;22(10):1548-56. doi:10.1359/jbmr.0070614
  27. Kellar J, Givertz A, Mathias J, Cohen J. Bisphosphonate-related Femoral Shaft Fracture. Clin Pract Cases Emerg Med. Feb 2020;4(1):62-64. doi:10.5811/cpcem.2019.10.45007
  28. Fayad LM, Kawamoto S, Kamel IR, et al. Distinction of long bone stress fractures from pathologic fractures on cross-sectional imaging: how successful are we? AJR Am J Roentgenol. Oct 2005;185(4):915-24. doi:10.2214/ajr.04.0950
  29. Mintz DN, Roberts CC, Bencardino JT, et al. ACR Appropriateness Criteria(®) Chronic Hip Pain. J Am Coll Radiol. May 2017;14(5s):S90-s102. doi:10.1016/j.jacr.2017.01.035
  30. Smith TO, Drew BT, Toms AP, Donell ST, Hing CB. Accuracy of magnetic resonance imaging, magnetic resonance arthrography and computed tomography for the detection of chondral lesions of the knee. Knee Surg Sports Traumatol Arthrosc. Dec 2012;20(12):2367-79. doi:10.1007/s00167-012-1905-x
  31. van Bergen CJ, van den Ende KI, Ten Brinke B, Eygendaal D. Osteochondritis dissecans of the capitellum in adolescents. World J Orthop. Feb 18 2016;7(2):102-8. doi:10.5312/wjo.v7.i2.102
  32. van Dijk CN, Reilingh ML, Zengerink M, van Bergen CJ. Osteochondral defects in the ankle: why painful? Knee Surg Sports Traumatol Arthrosc. May 2010;18(5):570-80. doi:10.1007/s00167-010-1064-x
  33. Fritz J, Lurie B, Potter HG. MR Imaging of Knee Arthroplasty Implants. Radiographics. Sep- Oct 2015;35(5):1483-501. doi:10.1148/rg.2015140216
  34. Fritz J, Lurie B, Miller TT, Potter HG. MR imaging of hip arthroplasty implants. Radiographics. Jul-Aug 2014;34(4):E106-32. doi:10.1148/rg.344140010
  35. Hart AJ, Sabah SA, Bandi AS, et al. Sensitivity and specificity of blood cobalt and chromium metal ions for predicting failure of metal-on-metal hip replacement. The Journal of Bone & Joint Surgery British Volume. 2011;93-B(10):1308-1313. doi:10.1302/0301-620x.93b10.26249
  36. Kransdorf MJ, Murphey MD, Wessell DE, et al. ACR Appropriateness Criteria(®) Soft- Tissue Masses. J Am Coll Radiol. May 2018;15(5s):S189-s197. doi:10.1016/j.jacr.2018.03.012
  37. Subhawong TK, Fishman EK, Swart JE, Carrino JA, Attar S, Fayad LM. Soft-tissue masses and masslike conditions: what does CT add to diagnosis and management? AJR Am J Roentgenol. Jun 2010;194(6):1559-67. doi:10.2214/ajr.09.3736
  38. American College of Radiology. ACR Appropriateness Criteria® Clinically Suspected Vascular Malformation of the Extremities. American College of Radiology. Updated 2019. Accessed March 30, 2023. https://acsearch.acr.org/docs/3102393/Narrative/
  39. American College of Radiology. ACR Appropriateness Criteria® Primary Bone Tumors. American College of Radiology. Updated 2019. Accessed January 23, 2023. https://acsearch.acr.org/docs/69421/Narrative/
  40. American College of Radiology. ACR Appropriateness Criteria® Malignant or Aggressive Primary Musculoskeletal Tumor-Staging And Surveillance. American College of Radiology. Updated 2022. Accessed January 23, 2023. https://acsearch.acr.org/docs/69428/Narrative/
  41. Holzapfel K, Regler J, Baum T, et al. Local Staging of Soft-Tissue Sarcoma: Emphasis on Assessment of Neurovascular Encasement-Value of MR Imaging in 174 Confirmed Cases. Radiology. May 2015;275(2):501-9. doi:10.1148/radiol.14140510
  42. Kircher MF, Willmann JK. Molecular body imaging: MR imaging, CT, and US. Part II. Applications. Radiology. Aug 2012;264(2):349-68. doi:10.1148/radiol.12111703
  43. NCCN Imaging Appropriate Use Criteria™. National Comprehensive Cancer Network (NCCN). Accessed January 23, 2023. https://www.nccn.org/professionals/imaging/default.aspx
  44. Felten R, Perrin P, Caillard S, Moulin B, Javier RM. Avascular osteonecrosis in kidney transplant recipients: Risk factors in a recent cohort study and evaluation of the role of secondary hyperparathyroidism. PLoS One. 2019;14(2):e0212931. doi:10.1371/journal.pone.0212931
  45. Murphey MD, Foreman KL, Klassen-Fischer MK, Fox MG, Chung EM, Kransdorf MJ. From the radiologic pathology archives imaging of osteonecrosis: radiologic-pathologic correlation. Radiographics. Jul-Aug 2014;34(4):1003-28. doi:10.1148/rg.344140019
  46. American College of Radiology. ACR Appropriateness Criteria® Osteonecrosis. American College of Radiology. Updated 2022. Accessed January 23, 2023. https://acsearch.acr.org/docs/69420/Narrative/
  47. Fukushima W, Fujioka M, Kubo T, Tamakoshi A, Nagai M, Hirota Y. Nationwide epidemiologic survey of idiopathic osteonecrosis of the femoral head. Clin Orthop Relat Res. Oct 2010;468(10):2715-24. doi:10.1007/s11999-010-1292-x
  48. Wali Y, Almaskari S. Avascular Necrosis of the Hip in Sickle Cell Disease in Oman: Is it serious enough to warrant bone marrow transplantation? Sultan Qaboos Univ Med J. Feb 2011;11(1):127-8.
  49. Rajani R, Quinn RH, Fischer SJ. Synovial Chondromatosis. American Academy of Orthopaedic Surgeons (AAOS). Updated January 2022. Accessed January 23, 2023. https://orthoinfo.aaos.org/en/diseases--conditions/synovial-chondromatosis
  50. Dodwell ER. Osteomyelitis and septic arthritis in children: current concepts. Curr Opin Pediatr. Feb 2013;25(1):58-63. doi:10.1097/MOP.0b013e32835c2b42
  51. Glaudemans A, Jutte PC, Cataldo MA, et al. Consensus document for the diagnosis of peripheral bone infection in adults: a joint paper by the EANM, EBJIS, and ESR (with ESCMID endorsement). Eur J Nucl Med Mol Imaging. Apr 2019;46(4):957-970. doi:10.1007/s00259-019- 4262-x
  52. Mandell JC, Khurana B, Smith JT, Czuczman GJ, Ghazikhanian V, Smith SE. Osteomyelitis of the lower extremity: pathophysiology, imaging, and classification, with an emphasis on diabetic foot infection. Emerg Radiol. Apr 2018;25(2):175-188. doi:10.1007/s10140-017-1564-9
  53. American College of Radiology. ACR Appropriateness Criteria® Suspected Osteomyelitis, Septic Arthritis, or Soft Tissue Infection (Excluding Spine and Diabetic Foot). American College of Radiology (ACR). Updated 2022. Accessed January 23, 2023. https://acsearch.acr.org/docs/3094201/Narrative/
  54. Fayad LM, Carrino JA, Fishman EK. Musculoskeletal infection: role of CT in the emergency department. Radiographics. Nov-Dec 2007;27(6):1723-36. doi:10.1148/rg.276075033
  55. Walker EA, Beaman FD, Wessell DE, et al. ACR Appropriateness Criteria® Suspected Osteomyelitis of the Foot in Patients With Diabetes Mellitus. J Am Coll Radiol. Nov 2019;16(11s):S440-s450. doi:10.1016/j.jacr.2019.05.027
  56. Bowers S, Franco E. Chronic Wounds: Evaluation and Management. Am Fam Physician. Feb 1 2020;101(3):159-166.
  57. Pitocco D, Spanu T, Di Leo M, et al. Diabetic foot infections: a comprehensive overview. Eur Rev Med Pharmacol Sci. Apr 2019;23(2 Suppl):26-37. doi:10.26355/eurrev_201904_17471
  58. Colebatch AN, Edwards CJ, Østergaard M, et al. EULAR recommendations for the use of imaging of the joints in the clinical management of rheumatoid arthritis. Ann Rheum Dis. Jun 2013;72(6):804-14. doi:10.1136/annrheumdis-2012-203158
  59. Jia Y, Tian H, Deng J, Yu K. Multimodal imaging for the clinical assessment of dermatomyositis and polymyositis: A systematic review. Radiology of Infectious Diseases. 2017/06/01/ 2017;4(2):81-87. doi:https://doi.org/10.1016/j.jrid.2017.01.003
  60. Joyce NC, Oskarsson B, Jin LW. Muscle biopsy evaluation in neuromuscular disorders. Phys Med Rehabil Clin N Am. Aug 2012;23(3):609-31. doi:10.1016/j.pmr.2012.06.006
  61. Chou H, Chin TY, Peh WC. Dual-energy CT in gout - A review of current concepts and applications. J Med Radiat Sci. Mar 2017;64(1):41-51. doi:10.1002/jmrs.223
  62. Domkundwar S, Autkar G, Khadilkar SV, Virarkar M. Ultrasound and EMG-NCV study (electromyography and nerve conduction velocity) correlation in diagnosis of nerve pathologies. J Ultrasound. Jun 2017;20(2):111-122. doi:10.1007/s40477-016-0232-3
  63. Dong Q, Jacobson JA, Jamadar DA, et al. Entrapment neuropathies in the upper and lower limbs: anatomy and MRI features. Radiol Res Pract. 2012;2012:230679. doi:10.1155/2012/230679
  64. Donovan A, Rosenberg ZS, Cavalcanti CF. MR imaging of entrapment neuropathies of the lower extremity. Part 2. The knee, leg, ankle, and foot. Radiographics. Jul-Aug 2010;30(4):1001-19. doi:10.1148/rg.304095188
  65. Tos P, Crosio A, Pugliese P, Adani R, Toia F, Artiaco S. Painful scar neuropathy: principles of diagnosis and treatment. Plastic and Aesthetic Research. 2015;2:156-164. doi:10.4103/2347- 9264.160878
  66. Guggenberger R, Pfirrmann CW, Koch PP, Buck FM. Assessment of lower limb length and alignment by biplanar linear radiography: comparison with supine CT and upright full-length radiography. AJR Am J Roentgenol. Feb 2014;202(2):W161-7. doi:10.2214/ajr.13.10782
  67. Sabharwal S, Kumar A. Methods for assessing leg length discrepancy. Clin Orthop Relat Res. Dec 2008;466(12):2910-22. doi:10.1007/s11999-008-0524-9
  68. Laya BF, Restrepo R, Lee EY. Practical Imaging Evaluation of Foreign Bodies in Children: An Update. Radiol Clin North Am. Jul 2017;55(4):845-867. doi:10.1016/j.rcl.2017.02.012
  69. Abousayed MM, Alley MC, Shakked R, Rosenbaum AJ. Adult-Acquired Flatfoot Deformity: Etiology, Diagnosis, and Management. JBJS Rev. Aug 2017;5(8):e7. doi:10.2106/jbjs.Rvw.16.00116
  70. Thorpe SW, Wukich DK. Tarsal coalitions in the adult population: does treatment differ from the adolescent? Foot Ankle Clin. Jun 2012;17(2):195-204. doi:10.1016/j.fcl.2012.03.004
  71. Iyer RS, Chapman T, Chew FS. Pediatric bone imaging: diagnostic imaging of osteoid osteoma. AJR Am J Roentgenol. May 2012;198(5):1039-52. doi:10.2214/ajr.10.7313
  72. Bouchard M, Mosca VS. Flatfoot deformity in children and adolescents: surgical indications and management. J Am Acad Orthop Surg. Oct 2014;22(10):623-32. doi:10.5435/jaaos-22-10- 623
  73. Glaser C. Tarsal Coalitions: A Practical Approach to a Not-So-Rare Entity. J Belg Soc Radiol. 2016;100(1):104. doi:10.5334/jbr-btr.1224
  74. Boas FE, Fleischmann D. CT artifacts: Causes and reduction techniques. Imaging Med. 2012;4(2):229-40.
  75. American Academy of Pediatrics. Five things physicians and patients should question: Do not order advanced imaging studies (MRI or CT) for most musculoskeletal conditions in a child until all appropriate clinical, laboratory and plain radiographic examinations have been completed. Choosing Wisely Initiative ABIM Foundation. Updated February 12, 2018. Accessed January 23, 2023. https://www.choosingwisely.org/clinician-lists/aap-posna-mri-or-ct-for- musculoskeletal-conditions-in-children/

Coding Section






Computed tomography, lower extremity; without contrast material



with contrast material(s)



without contrast material, followed by contrast material(s) and further sections

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" 

History From 2024 Forward 

01012024  NEW POLICY 

Complementary Content