Clinical Policy Bulletin: Open Air, Low Field Strength, and Positional Magnetic Resonance Imaging (MRI) Units
Aetna considers magnetic resonance imaging (MRI) medically necessary for appropriate indications without regard to the field strength or configuration of the MRI unit. Aetna considers intermediate and low field strength MRI units to be an acceptable alternative to standard full strength MRI units.
Aetna considers "open" MRI units of any configuration, including MRI units that allow imaging when standing (Stand-Up MRI) or when sitting, to be an acceptable alternative to standard "closed" MRI units.
Aetna considers repeat MRI scans in different positions (such as flexion, extension, rotation and lateral bending) and when done with and without weight-bearing to be experimental and investigational because of insufficient evidence of this approach.
Standing MRIs (e.g., The Stand-UpTM MRI, FONAR, Melville, NY) allows patients to walk in and be scanned while standing.
Standing MRIs are equipped with a system that positions the patient in the magnet and places the anatomy of interest at the center of the magnet gap. The standing MRI can also rotate a patient from the vertical to the horizontal position so the patient can be scanned lying down. MRIs have also been developed that can scan patients in a sitting position [Position MRITM (pMRITM )].
The standing MRI and sitting MRI may be an alternative to open MRI for imaging someone with claustrophobia.
Standing MRIs allows the spine, joints and other parts of the body to be imaged in the weight bearing state. In theory, if one can scan the patient in a load-bearing position, one can more accurately identify the precise source of pain. The standing MRI can also image someone in various positions (e.g., flexion, extension, rotation, and lateral bending). Currently, standing radiographs are used to examine patients in the standing position or other positions.
The clinical value of standing MRI or position MRI imaging in various positions (e.g., flexion, extension, rotation and lateral bending) has not been systematically evaluated in clinical studies. It has not been demonstrated in published prospective clinical studies that performing MRIs in these various positions can consistently detect problems that can not be detected with a standard MRI.
An assessment of standing, weight-bearing, positional, and upright MRIs by the Washington State Department of Labor and Industries (2006) concluded: "There is limited scientific data available on the accuracy and diagnostic utility of standing, upright, weight-bearing or positional MRI. Well-designed clinical trials are necessary to effectively determine the potential benefits and value of this diagnostic imaging method. . . . Due to the lack of evidence addressing diagnostic accuracy or diagnostic utility, standing, weight-bearing, positional magnetic resonance imaging is considered investigational and experimental".
Supported by findings of a technology assessment of upright, positional and weight-bearing MRIs (Skelly et al, 2007), the Washington State Health Care Authority found that "there was insufficient scientific evidence to make any conclusions about uMRI’s effectiveness, including whether uMRI: accurately identifies an appropriate diagnosis; can safely and effectively replace other tests; or results in equivalent or better diagnostic or therapeutic outcomes".
Diefenbach et al (2013) examined if an upright positional MRI protocol could produce reliable spinal curvature images and measurements compared with traditional radiograph. A total of 25 consecutive patients (16 females; 9 males; average age of 14.6 yrs; range of 12 to 18) with a diagnosis of adolescent idiopathic scoliosis (AIS) were enrolled in this study. Average major curve magnitude was 30° (range of 6 to 70). Subjects received anterior-posterior as well as lateral plain radiographical scoliosis imaging followed within 1 week by uMRI; MRI data acquisition was performed in less than 7 mins. Two independent observers performed all Cobb angle, T5-T12 kyphosis, and vertebral rotation measurements for comparison. The Pearson correlation method was performed to compare radiograph to uMRI measurements, while inter-rater and intra-rater correlations were performed to assess reliability. These investigators found outstanding correlation between all plain film radiography and uMRI measurements (p = 0.01); major Cobb angles (R = 0.901), minor Cobb angles (R = 0.838), and kyphosis (R = 0.943). Inter-rater reliability for both radiographical and MRI measurements of major Cobb angles (R = 0.959, 0.896, respectively), minor Cobb angles (R = 0.951, 0.857, respectively), and vertebral rotation (R = 0.945) were outstanding. Intra-rater reliability for both radiographical and MRI measurements of major Cobb angles (R = 0.966, 0.966, respectively) and minor Cobb angles (R = 0.945, 0.943, respectively) were also outstanding. The authors concluded that these results showed that uMRI is capable of producing coronal and sagittal plane measurements that highly correlate with traditional plain film radiographical measurements. This, in addition to reliable vertebral rotation measurements, makes uMRI a valuable, radiation-free alternative/substitute for diagnostic evaluation in AIS.
CPT Codes / HCPCS Codes / ICD-9 Codes
CPT codes covered if selection criteria are met:
70551 - 70553
70554 - 70555
72195 - 72197
73218 - 73223
73718 - 73723
74181 - 74183
HCPCS code covered if selection criteria are met:
Magnetic resonance imaging (MRI), low-field
ICD-9 codes covered if selection criteria are met:
Too many to list
The above policy is based on the following references:
Kajander S, Kallio T, Alanen A, et al. Imaging end-stage kidney disease in adults. Low-field MR imaging with magnetization transfer vs. ultrasonography. Acta Radiol. 2000;41(4):357-360.
Loew R, Kreitner KF, Runkel M, et al. MR arthrography of the shoulder: Comparison of low-field (0.2 T) vs high-field (1.5 T) imaging. Eur Radiol. 2000;10(6):989-996.
Hottya GA, Peterfy CG, Uffmann M, et al. Dedicated extremity MR imaging of the foot and ankle. Eur Radiol. 2000;10(3):467-475.
Tung GA, Entzian D, Green A, et al. High-field and low-field MR imaging of superior glenoid labral tears and associated tendon injuries. AJR Am J Roentgenol. 2000;174(4):1107-1114.
Steinborn M, Heuck A, Jessel C, et al. Magnetic resonance imaging of lateral epicondylitis of the elbow with a 0.2-T dedicated system. Eur Radiol. 1999;9(7):1376-1380.
Merl T, Scholz M, Gerhardt P, et al. Results of a prospective multicenter study for evaluation of the diagnostic quality of an open whole-body low-field MRI unit. A comparison with high-field MRI measured by the applicable gold standard. Eur J Radiol. 1999;30(1):43-53.
Rand T, Imhof H, Turetschek K, et al. Comparison of low field (0.2T) and high field (1.5T) MR imaging in the differentiation of torned from intact menisci. Eur J Radiol. 1999;30(1):22-27.
Rand T, Ahn JM, Muhle C, et al. Ligaments and tendons of the ankle. Evaluation with low-field (0.2 T) MR imaging. Acta Radiol. 1999;40(3):303-308.
Davis MC. High- vs. low-field MR: What's the difference? Diagn Imaging (San Franc). 1998;Suppl Open MRI:MR28-MR30.
Verhoek G, Zanetti M, Duewell S, et al. MRI of the foot and ankle: Diagnostic performance and patient acceptance of a dedicated low field MR scanner. J Magn Reson Imaging. 1998;8(3):711-716.
Marshall D. Magnetic field strength issues in magnetic resonance imaging. Ottawa, ON: Canadian Coordinating Office for Health Technology Assessment (CCOHTA); 1993.
Rupprecht T, Nitz W, Wagner M, et al. Determination of the pressure gradient in children with coarctation of the aorta by low-field magnetic resonance imaging. Pediatr Cardiol. 2002;23(2):127-131.
GE Medical Systems. FONAR Standing Ovation Magnetic Resonance Imaging [website]. Chalfont St. Giles, UK: GE Medical Systems; 2003. Available at: http://www.gemedicalsystems.com/rad/mri/products/fonar/. Accessed August 11, 2003.
Danielson B, Willen J. Axially loaded magnetic resonance image of the lumbar spine in asymptomatic individuals. Spine. 2001;26(23):2601-2606.
Willen J, Danielson B. The diagnostic effect from axial loading of the lumbar spine during computed tomography and magnetic resonance imaging in patients with degenerative disorders. Spine. 2001;26(23):2607-2614.
Weishaupt D, Boxheimer L. Magnetic resonance imaging of the weight-bearing spine. Semin Musculoskelet Radiol. 2003;7(4):277-286.
Manenti G, Liccardo G, Sergiacomi G, et al. Axial loading MRI of the lumbar spine. In Vivo. 2003;17(5):413-420.
Jinkins JR, Dworkin J. Proceedings of the State-of-the-Art Symposium on Diagnostic and Interventional Radiology of the Spine, Antwerp, September 7, 2002 (Part two). Upright, weight-bearing, dynamic-kinetic MRI of the spine: pMRI/kMRI. JBR-BTR. 2003;86(5):286-293.
Saifuddin A, Blease S, MacSweeney E. Axial loaded MRI of the lumbar spine. Clin Radiol. 2003;58(9):661-671.
Hagio K, Sugano N, Nishii T, et al. A novel system of four-dimensional motion analysis after total hip arthroplasty. J Orthop Res. 2004;22(3):665-670.
Jinkins JR, Dworkin JS, Damadian RV. Upright, weight-bearing, dynamic-kinetic MRI of the spine: Initial results. Eur Radiol. 2005;15(9):1815-1825.
Vitaz TW, Shields CB, Raque GH, et al. Dynamic weight-bearing cervical magnetic resonance imaging: Technical review and preliminary results. South Med J. 2004;97(5):456-461.
Hailey D. Open magnetic resonance imaging (MRI) scanners. Issues in Emerging Health Technologies. Issue 92. Ottawa, ON; Canadian Agency for Drugs and Technologies in Health (CADTH); 2006.
Washington State Department of Labor and Industries, Office of the Medical Director. Standing, weight-bearing, positional, or upright magnetic resonance imaging. Health Technology Assessment. Olympia, WA: Washington State Department of Labor and Industries; May 31, 2006. Available at: http://www.lni.wa.gov/ClaimsIns/Providers/Treatment/SpecCovDec/StandMRI.asp. Accessed September 20, 2006.
Freeston JE, Conaghan PG, Dass S, et al. Does extremity-MRI improve erosion detection in severely damaged joints? A study of long-standing rheumatoid arthritis using three imaging modalities. Ann Rheum Dis. 2007;66(11):1538-1540.
Skelley AC, Moore E, Dettori JR. Effectiveness of upright MRI for evaluation of patients with suspected spinal or extra-spinal joint dysfunction. Comprehensive Evidence-based Health Technology Assessment. Prepared by Spectrum Research for the Health Technology Assessment Program. Olympia, WA: Washington State Health Care Authority; May 11, 2007.
Washington State Health Care Authority, Health Technology Clinical Committee. Upright/positional MRI. Findings and Coverage Decision. 20070501. Olympia, WA: Washington State Health Care Authority; May 11, 2007.
Diefenbach C, Lonner BS, Auerbach JD, et al. Is radiation-free diagnostic monitoring of adolescent idiopathic scoliosis feasible using upright positional magnetic resonance imaging? Spine (Phila Pa 1976). 2013;38(7):576-580.
Copyright Aetna Inc. All rights reserved. Clinical Policy Bulletins are developed by Aetna to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. This Clinical Policy Bulletin contains only a partial, general description of plan or program benefits and does not constitute a contract. Aetna does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Aetna or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. This Clinical Policy Bulletin may be updated and therefore is subject to change.