Magnetic resonance imaging (MRI) is used in the evaluation, diagnosis, and management of spine-related conditions, e.g., degenerative disc disease, cauda equine compression, radiculopathy, infections, or cancer in the lumbar spine. MRI provides high quality multiplanar images of organs and structures within the body without the use of x-rays or radiation. In the lumbar area where gonadal exposure may occur, MRI’s lack of radiation is an advantage.

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.
 

INDICATIONS FOR LUMBAR SPINE MRI

Policy
Lumbar spine MRI is considered MEDICALLY NECESSARY for the following indications:

If there is a combination request* for an overlapping body part, either requested at the same time or sequentially (within the past 3 months) the results of the prior study should be:

• Inconclusive or show a need for additional or follow up imaging evaluation OR
• The office notes should clearly document an indication why overlapping imaging is needed and how it will change management for the patient.
   

*Unless approvable in the combination section as noted in the guidelines.

Evaluation of Neurologic Deficits (1,2)

• With any of the following new neurological deficits documented on physical exam
  • Extremity muscular weakness (and not likely caused by plexopathy or peripheral neuropathy)(3)
  • Pathologic or abnormal reflexes (and not likely caused by plexopathy, or peripheral neuropathy)(4)
  • Absent/decreased sensory changes along a particular lumbar dermatome (nerve distribution): pin prick, touch, vibration, proprioception or temperature (and not likely caused by plexopathy, or peripheral neuropathy)
  • Lower extremity increased muscle tone
  • New onset bowel or bladder dysfunction (e.g., retention or incontinence)—not related to an inherent bowel or bladder process
  • Gait abnormalities (see Table 1 below for more details)
  • New onset foot drop (Not related to a peripheral nerve injury, e.g., peroneal nerve)
• Cauda Equina Syndrome as evidence by severe back pain/sciatica along with one of the defined symptoms (see Cauda Equina Syndrome section)

Evaluation of Back Pain (5)
With any of the Following:

• Abnormal neurologic examination
• Early morning stiffness and/or gelling
• Night pain that prevents or disrupts sleep
• Radicular pain
• Fever or weight loss or malaise
• Postural changes (e.g., kyphosis or scoliosis)
• Limp (or refusal to walk in a younger child)

Pre-Operative/Post-Operative/Procedural Evaluation
As part of initial pre-operative/post-operative/procedural evaluation (The best examinations are CT to assess for hardware complication, extent of fusion and pseudarthrosis and MRI for cord, nerve root compression, disc pathology, or post-op infection)(5)

• For preoperative evaluation/planning
• CSF leak highly suspected and supported by patient history and/or physical exam findings (leak (known or suspected spontaneous (idiopathic) intracranial hypotension (SIH), post lumbar puncture headache, post spinal surgery headache, orthostatic headache, rhinorrhea or otorrhea, or cerebrospinal-venous fistula))⁽⁹⁾
• A follow-up study may be needed to help evaluate a patient’s progress after treatment, procedure, intervention, or surgery in the last 6 months. Documentation requires a medical reason that clearly indicates why additional imaging is needed for the type and area(s) requested (routine surveillance post-op not indicated without symptoms)
• Surgical infection as evidenced by signs/symptoms, laboratory, or prior imaging findings
• New or changing neurological deficits or symptoms post-operatively⁽¹⁰⁾ (see

neurological deficitsection above).

• When combo requests (see above statement⁺) are submitted (i.e., MRI and CT of the spine), the office notes should clearly document the need for both studies to be done simultaneously (e.g., the need for both soft tissue and bony anatomy is required)⁽¹¹⁾
  • Combination requests where both lumbar spine CT and MRI lumbar spine are both approvable (not an all-inclusive list):
    • Pathologic or complex fractures
    • Malignant process of spine with both bony and soft tissue involvement
    • Clearly documented indication for bony and soft tissue abnormality where assessment will change management for the patient

Evaluation of Trauma or Acute Injury (12)

• Presents with any of the following neurologicaldeficitsas above
• With progression or worsening of symptoms during the course of conservative treatment*
• History of underlying spinal abnormalities (i.e., ankylosing spondylitis) (Both MRI and CT are approvable)^(13,14)
• When the patient is clinically unevaluable or there are preliminary imaging findings (x-ray or CT) needing further evaluation

MRI and CT provide complementary information. When indicated it is appropriate to perform both examinations(13)

Pars Defect (Spondylolysis) or Spondylolisthesis (15,16)

• Pars defect (spondylolysis) or spondylolisthesis in adults when Flexion/Extension x- rays show instability⁽¹⁷⁾
• Clinically suspected Pars defect (spondylolysis) after plain films in pediatric population (< 18 yr.) or athletes (flexion extension instability not required) and imaging would change treatment⁽⁷⁾

NOTE: Initial imaging (x-ray, or planar bone scan without SPECT; Bone scan with SPECT is superior to MRI and CT in the detection of pars interarticularis pathology including spondylolysis)(7)

Evaluation of Known Fracture or New Compression Fractures (18)
(With Worsening Back Pain)

• With history of malignancy
  • To aid in differentiation of benign osteoporotic fractures from metastatic disease
    • A follow-up MRI in 6-8 weeks after initial MRI when initial imaging cannot decipher (indeterminate) benign osteoporotic fracture from metastatic disease⁽¹⁹⁾
• With an associated new focal neurologicdeficitas above⁽¹²⁾
• Prior to a planned surgery/intervention or if the results of the MRI will change management

Evaluation of Tumor, Cancer, or Metastasis
With any of the Following:
MRI is usually the preferred study (CT may be needed to further characterize solitary indeterminate lesions seen on MRI)(20,21,22)

• Primary tumor
  • Initial staging primary spinal tumor⁽²³⁾
  • Follow-up of known primary cancer of patient undergoing active treatment within the past year or as per surveillance imaging guidance for that cancer
  • Known spinal tumor with new signs or symptoms (e.g., new or increasing nontraumatic pain, physical, laboratory, and/or imaging findings)
  • With an associated new focal neurologicdeficitas above⁽¹²⁾
• Metastatic tumor
  • With evidence of metastasis on bone scan needing further clarification OR inconclusive findings on a prior imaging exam
  • With an associated new focal neurologic deficit⁽¹²⁾
  • Known malignancy with new signs or symptoms (e.g., new or increasing nontraumatic pain, radiculopathy or back pain that occurs at night and wakes the patient from sleep with known active cancer, physical, laboratory, and/or imaging findings) in a tumor that tends to metastasize to the spine⁽²⁴⁾

Further Evaluation of Indeterminate Findings
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).

Evaluation of Known or Suspected Infection/Abscess (25,26)

• Spondyloarthropathies
  • Ankylosing Spondylitis/Spondyloarthropathies with non-diagnostic or indeterminate x-ray and rheumatology workup

e.g., osteomyelitis

Evaluation of Spine Abnormalities Related to Immune System Suppression (25)

• As evidenced by signs/symptoms, laboratory, or prior imaging findings

E.g., HIV, chemotherapy, leukemia, or lymphoma

Other Indications for Lumbar Spine MRI
Note: See combination requests, below, for initial advanced imaging assessment and pre- operatively

• Tethered cord or spinal dysraphism (known or suspected), based on preliminary imaging, neurological exam, and/or high-risk cutaneous stigmata^(27,28,29)
• Known anorectal malformations⁽³⁰⁾
• Suspicious sacral dimple (those that are deep, larger than 0.5 cm, located within the superior portion of the gluteal crease or above the gluteal crease, multiple dimples, or associated with other cutaneous markers) or duplicated or deviated gluteal cleft⁽³¹⁾
  • Patients <3 months should have ultrasound
• Toe walking in a child when associated with upper motor neuron signs, including hyperreflexia, spasticity; or orthopedic deformity with concern for spinal cord pathology and/or tethered cord (e.g., pes cavus, clawed toes, leg or foot length deformity (excluding tight heel cords))⁽³²⁾
• Known Chiari II (Arnold-Chiari syndrome), III, or IV malformation⁽²⁹⁾
• For follow-up/repeat evaluation of Arnold-Chiari I with new signs or symptoms suggesting recurrent spinal cord tethering (For initial diagnosis see below)
• Suspected neuroinflammatory Conditions/Diseases (e.g., sarcoidosis, Behcet’s)- After detailed neurological exam and appropriate initial work up completed
• Follow-up known neuroinflammatory Conditions/Diseases (e.g., sarcoidosis, Behcet’s) with new or worsening signs/symptoms or to evaluate treatment response

Genetics and Rare Diseases

• For other syndromes and rare diseases not otherwise addressed in the guideline, coverage is based on a case-by-case basis using societal guidance.

Combination Studies
Brain/Cervical/Thoracic/Lumbar/Abdomen MRI

• Von Hippel Lindau (VHL) every 2 years starting at age 15⁽³³⁾

Brain MRI/Cervical Spine MRI/ Thoracic Spine MRI/Lumbar Spine MRI (any combination)
For initial evaluation of a suspected Arnold Chiari malformation

• Follow-up imaging of a known type II or type III Arnold Chiari malformation. For Arnold Chiari type I, follow-up imaging only if new or changing signs/symptoms (34,35,36)
• Oncological Applications (e.g., primary nervous system, metastatic)
  • Drop metastasis from brain or spine
  • Suspected leptomeningeal carcinomatosis⁽³⁷⁾
• CSF leak highly suspected and supported by patient history and/or physical exam findings (known or suspected spontaneous (idiopathic) intracranial hypotension (SIH), post lumbar puncture headache, post spinal surgery headache, orthostatic headache, rhinorrhea or otorrhea, or cerebrospinal-venous fistula)
• For evaluation of known Arnold-Chiari Malformation
• Tumor evaluation and monitoring in cancer predisposition syndromes
  • Von Hippel Lindau (VHL) - imaging of the brain and spinal cord for hemangioblastomas every 2 years starting at age 14 ^(38,39,40)
  • Rhabdoid Tumor Predisposition Syndrome- Brain and Spine MRI at diagnosis and monthly age 0-6 months if whole body MRI not done; Q2-3 months age 7- 18months, Q3months age 19 months-5 years
  • NF-2- Brain IAC annually starting at the age of 10 years and spinal imaging at baseline and every 2 to 3 years with more frequent imaging, if warranted, based on sites of tumor involvement ⁽⁴¹⁾
  • Schwannomatosis - Brain and spine MRI every two to three years beginning at age 12 years