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 LOWER EXTREMITY MRI (FOOT, ANKLE, KNEE, LEG or HIP)
(Plain radiographs must precede MRI evaluation)

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

If an MR arthrogram fits approvable criteria below, approve as MRI
Joint or muscle pain without positive findings on an orthopedic exam as listed below and , after X-ray completed^1,2,3 (does not apply to young children).

• 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 weeks
• With progression or worsening of symptoms during the course of conservative treatment

Joint specific approvable provocative orthopedic examination tests and suspected injuries⁴

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).

ANKLE^5,6,7

• 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

KNEE^{1,8,9,10,11,12}

• 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 completed^13,14
  • 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

HIP

• 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 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-Ray^21,22,23,24 (not listed in above)

• 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)

Trauma
Bone Fracture

• Hip and Femur
  • Suspected occult, stress or insufficiency fracture with a negative or non-diagnostic initial X-ray:²⁵
    • Approve an immediate MRI (no follow up radiographs required) — MRI preferred test
  • Suspicion of a hip fracture in a pregnant patient does not require an initial X-ray
• 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 non-diagnostic²⁶
  • If at high risk for a complete fracture with conservative therapy (e.g., navicular bone), then immediate MRI is warranted²⁷
• Pathologic or concern for impending fracture on X-ray or CT²⁸ — approve immediate MRI
• Suspected ligamentous/tendon injury with known fractures on X-ray/CT that may require surgery
• 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, CT is the preferred study²⁹

Osteochondral lesions (defects, fractures, osteochondritis dissecans) and X-ray completed^8,30,31,32

• 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-rays^33,34
• Suspected Metallosis with painful metal on metal hip replacement after initial X-rays

Extremity Mass³⁵

• Mass or lesion after non-diagnostic x-ray or ultrasound.36 CT is better than MRI to evaluate mass calcification or bone involvement and may complement or replace MRI³⁷
  • Baker’s cyst should be initially evaluated with ultrasound
  • If superficial mass, then ultrasound is the initial study
  • If deep mass, then X-ray is the initial study
• Vascular malformations
  • After initial evaluation with ultrasound and results will change management
  • Inconclusive ultrasound
  • For preoperative planning
  • MRA is also approvable
  • Follow up after treatment/embolization

Known Primary Cancer of the Extremity^{38,39,40,41,42}

• 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 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 (i.e., X-ray, ultrasound or CT) 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 (e.g., avascular necrosis [AVN], Legg-Calve-Perthes Disease)^43,44,45

• To further characterize a prior abnormal x-ray or CT suggesting osteonecrosis
• Normal or indeterminate X-rays, but symptomatic and high risk (such as glucocorticosteroid use, renal transplant, glycogen storage disease, alcohol abuse, sickle cell anemia)⁴⁶
• Known osteonecrosis to evaluate a contralateral joint after initial X-rays

Loose bodies or synovial chondromatosis and after X-ray or ultrasound completed

• In the setting of joint pain or mechanical symptoms^47,48

Infection of bone, joint, or soft tissue abscess^49,50,51

• Abnormal X-ray or ultrasound
• Negative X-ray or ultrasound but with a clinical suspicion of infection based on either of the following:
  • Signs and symptoms of joint or bone infection include:
    • Pain and swelling
    • Decreased 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 suspected
  • Increased suspicion if size or temperature increases, bone is exposed/positive probe-to-bone test, new areas of breakdown, new smell⁵²
• Neuropathic foot with friable or discolored granulation tissue, foul odor, non-purulent discharge, and delayed wound healing⁵³

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 sign⁵⁴ or other indication of muscle or nerve damage after recent hip surgery

For evaluation of known or suspected autoimmune disease (e.g., rheumatoid arthritis)⁵⁵

• 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 noncontributory

Known or suspected inflammatory myopathies: (Includes polymyositis, dermatomyositis, immune-mediated necrotizing myopathy, inclusion body myositis)^56,57

• For diagnosis
• For biopsy planning

Peripheral nerve entrapment (e.g., tarsal tunnel, Morton’s neuroma)^58,59,60,61

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

Foreign body⁶²

• Indeterminate X-ray and ultrasound

Painful acquired or congenital flatfoot deformity in an adult, after X-ray completed
After failure of active conservative therapy listed above^63,64

Special pediatric considerations

• Painful flatfoot deformity with suspected tarsal coalition, not responsive to active conservative care⁶⁵
• Slipped Capital Femoral Epiphysis with negative frog leg and AP x-rays of the hips but clinically suspected^66,67,68
  • Drehmann sign
  • Limited internal rotation of the hip
  • Consider imaging the asymptomatic contralateral hip with a normal x-ray to detect early SCFE if prophylactic surgery is planned69
• Chronic recurrent multifocal osteomyelitis after initial work-up (labs (i.e. CRP/ESR and x-ray)^70,71 (Whole body bone marrow MRI is more appropriate when multiple  joints requested see NIA_CG_059)
• Acute limp in a child 5 or less years old
  • Concern for infection not localized to the hip (initial imaging not required)⁷²
  • Concern for infection localized to the hip after initial evaluation with ultrasound⁷²
• Osteoid Osteoma — MRI not usually done because X-ray and CT more accurate for diagnosis⁷³

Rationale
Magnetic resonance imaging shows the soft tissues and bones. With its multiplanar capabilities, high contrast, and high spatial resolution, it is an accurate diagnostic tool for conditions affecting the joint and adjacent structures. MRI can positively influence clinicians’ diagnoses and management plans for patients with conditions such as primary bone cancer, fractures, abnormalities in ligaments/tendons/cartilage, septic arthritis, and infection/inflammation.

OVERVIEW
*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, (including 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).

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.”⁷⁴ 

References

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 January 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. 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
7. 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. 
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. Morshed S. Current Options for Determining Fracture Union. Adv Med. 2014;2014:708574. doi:10.1155/2014/708574
30. 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
31. 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
32. 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
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. Church DJ, Krumme J, Kotwal S. Evaluating Soft-Tissue Lumps and Bumps. Mo Med. Jul-Aug 2017;114(4):289-294. 
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® Primary Bone Tumors. American College of Radiology. Updated 2019. Accessed January 23, 2023. https://acsearch.acr.org/docs/69421/Narrative/
39. NCCN Imaging Appropriate Use Criteria™. National Comprehensive Cancer Network (NCCN). Accessed Janaury 23, 2023.  https://www.nccn.org/professionals/imaging/default.aspx
40. 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
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. 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/
43. 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
44. 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
45. Murphey MD, Roberts CC, Bencardino JT, et al. ACR Appropriateness Criteria Osteonecrosis of the Hip. J Am Coll Radiol. Feb 2016;13(2):147-55. doi:10.1016/j.jacr.2015.10.033
46. 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. 
47. Bargiela A. [The usefulness of ultrasonography in synovial disease]. Radiologia. Jul-Aug 2010;52(4):301-10; quiz 377-8. Utilidad de la ecografía en el estudio de la enfermedad sinovial. doi:10.1016/j.rx.2010.02.001
48. Habusta SF, Mabrouk A, Tuck JA. Synovial Chondromatosis. StatPearls. StatPearls Publishing Copyright © 2023, StatPearls Publishing LLC.; 2023.
49. 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/ 
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. Bowers S, Franco E. Chronic Wounds: Evaluation and Management. Am Fam Physician. Feb 1 2020;101(3):159-166. 
53. 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 54.
54. Gogu S, Gandbhir VN. Trendelenburg Sign. StatPearls Publishing. Updated November 14, 2022. Accessed January 23, 2023. https://www.ncbi.nlm.nih.gov/books/NBK555987/
55. 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
56. 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
57. 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
58. 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
59. 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
60. 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
61. 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
62. 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
63. 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
64. 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
65. 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
66. Hesper T, Zilkens C, Bittersohl B, Krauspe R. Imaging modalities in patients with slipped capital femoral epiphysis. J Child Orthop. Apr 2017;11(2):99-106. doi:10.1302/1863-2548-11-160276
67. Kamegaya M, Saisu T, Nakamura J, Murakami R, Segawa Y, Wakou M. Drehmann sign and femoro-acetabular impingement in SCFE. J Pediatr Orthop. Dec 2011;31(8):853-7. doi:10.1097/BPO.0b013e31822ed320
68. Peck DM, Voss LM, Voss TT. Slipped Capital Femoral Epiphysis: Diagnosis and Management. Am Fam Physician. Jun 15 2017;95(12):779-784. 
69. Balch Samora J, Adler B, Druhan S, et al. MRI in idiopathic, stable, slipped capital femoral epiphysis: evaluation of contralateral pre-slip. J Child Orthop. Oct 1 2018;12(5):454-460. doi:10.1302/1863-2548.12.170204
70. Roderick MR, Shah R, Rogers V, Finn A, Ramanan AV. Chronic recurrent multifocal osteomyelitis (CRMO) - advancing the diagnosis. Pediatr Rheumatol Online J. Aug 30 2016;14(1):47. doi:10.1186/s12969-016-0109-1
71. Zhao DY, McCann L, Hahn G, Hedrich CM. Chronic nonbacterial osteomyelitis (CNO) and chronic recurrent multifocal osteomyelitis (CRMO). J Transl Autoimmun. 2021;4:100095. doi:10.1016/j.jtauto.2021.100095
72. Safdar NM, Rigsby CK, Iyer RS, et al. ACR Appropriateness Criteria(®) Acutely Limping Child Up To Age 5. J Am Coll Radiol. Nov 2018;15(11s):S252-s262. doi:10.1016/j.jacr.2018.09.030
73. 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
74. 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 

Codes	Number	Description
CPT	73718	Magnetic resonance (e.g., proton) imaging, lower extremity other than joint; without contrast material(s)
	73719	with contrast material(s)
	73720	without contrast material(s), followed by contrast material(s) and further sequences
	73721	Magnetic resonance (e.g., proton) imaging, any joint of lower extremity; without contrast material
	73722	with contrast material(s)
	73723	without contrast material(s), followed by contrast material(s) and further sequences
	0698T	Quantitative magnetic resonance for analysis of tissue composition (eg, fat, iron, water content), including multiparametric data acquisition, data preparation and transmission, interpretation and report, multiple organs

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 2019 Forward 

12/04/2023	Annual review, updating entire policy for clarity. Adding verbiage regarding orthopedic signs updated, clarifying hip vs pelvis imaging, indeterminate findings metallosis, and indications not addressed in the policy.
12/06/2022	Annual review, no change to policy intent. Policy updated for specificity and clarity.
12/06/2021	Annual review, adding policy verbiage related to unstable syndesmotic injury, navicular bone to hgh risk stress fracture, suspected bone infection in the setting of ulcers and neuropathy, following treatment for rheumatoid arthritis, clarifying pre and post operative statements. Also updating description and references.
12/01/2020	Annual review, added policy verbiage for pediatrics, loose bodies, delayed union, flatfoot, labral tear and joint implants/hardware. Also updating description and references.
12/17/2019	NEW POLICY