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 THORACIC SPINE CT
+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 (the entire spinal cord and/or autonomic postganglionic chain must be assessed).

 (*Unless approvable in the combination section as noted in the guidelines)

Evaluation of Neurologic Deficits^1,2
When Thoracic Spine MRI Is Contraindicated or Inappropriate

• 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 (e.g., Babinski, Lhermitte's sign⁴, Chaddock Sign⁵, Hoffman’s and other upper motor neuron signs); OR abnormal deep tendon reflexes (and not likely caused by plexopathy, or peripheral neuropathy)
  • Absent/decreased sensory changes along a particular thoracic dermatome (nerve distribution): pin prick, touch, vibration, proprioception, or temperature weakness (and not likely caused by plexopathy, or peripheral neuropathy)
  • Upper or lower extremity increase muscle tone/spasticity and likely localized to the thoracic spinal cord
  • 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)
• Suspected cord compression with any neurological deficits as listed above

Evaluation of Back Pain⁶
With any of the following when Thoracic Spine MRI Is Contraindicated

• With an abnormal electromyography (EMG) or nerve conduction study (if performed) indicating a thoracic radiculopathy. (EMG is not recommended to determine the cause of axial lumbar, thoracic, or cervical spine pain)⁷
• Isolated back pain in pediatric population^8,9 (conservative care not required if red flags present). Red flags that prompt imaging include any ONE of the following:
  • Age 5 or younger
  • Constant pain
  • Pain lasting > 4 weeks
  • 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)⁶

Note: If ordered by neurosurgeon or orthopedic surgeon for purposes of surgical planning, a contraindication to MRI is not required.

• Surgical infection as evidenced by signs/symptoms, laboratory, or prior imaging findings
• New or changing neurological deficits or symptoms post-operatively¹¹ (see neurological deficit section above).
• When combo requests 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)¹²
  • Combination requests where both thoracic spine CT and MRI thoracic spine are both approvable (not an all-inclusive list):
    • OPLL (Ossification of posterior longitudinal ligament)

□     Most common in cervical spine (rare but more severe in thoracic spine)¹³

• • • 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 Suspected Myelopathy^14,15
When Thoracic Spine MRI Is Contraindicated

• Does NOT require conservative care
• Progressive symptoms including unsteadiness; broad-based gait; increased muscle tone; pins and needles sensation; weakness and wasting of the lower limbs; diminished sensation to light touch, temperature, proprioception, and vibration; limb hyperreflexia and pathologic reflexes; bowel and bladder dysfunction in more severe cases
• Any of the neurological deficits as noted above

Evaluation of Trauma or Acute Injury¹⁶

• Presents with any of the following neurological deficits as above
• With progression or worsening of symptoms during the course of conservative treatment*
• History of underlying spinal abnormalities (i.e., ankylosing spondylitis, diffuse idiopathic skeletal hyperostosis) (Both MRI and CT are approvable)^17,18,19
• 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

Evaluation of Known Fracture or Known/New Compression Fractures^16,20
(With Worsening Back Pain)

• To assess union of a fracture when physical examination, plain radiographs, or prior imaging suggest delayed or non-healing
• To determine the position of fracture fragments
• With history of malignancy (if MRI is contraindicated or cannot be performed)
• With an associated new focal neurologic deficit as above
• Prior to a planned surgery/intervention or if the results of the CT will change management

CT Myelogram^10,21
When MRI Cannot Be Performed/Contraindicated/Surgeon Preference

When signs and symptoms inconsistent or not explained by the MRI findings

• Demonstration of the site of a CSF 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)
• Surgical planning, especially regarding to the nerve roots or evaluation of dural sac

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)^22,23

• Primary tumor
  • Initial staging primary spinal tumor²⁴
  • 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 neurologic deficit as above¹⁶
• 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 deficit¹⁶
  • Known malignancy with new signs or symptoms (e.g., new or increasing nontraumatic pain, radiculopathy or neck 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^25,26

Evaluation of Known or Suspected Infection/Abscess/Inflammatory disease (27)
When Thoracic Spine MRI Is Contraindicated or Cannot Be Performed

• As evidenced by signs and/or symptoms, laboratory (i.e., abnormal white blood cell count, ESR and/or CRP) or prior imaging findings
• Follow-up imaging of infection
  • With worsening symptoms/laboratory values (i.e., white blood cell count, ESR/CRP) or radiographic findings

E.g., Osteomyelitis

Spondyloarthropathies

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

Evaluation of Spine Abnormalities Related to Immune System Suppression²⁷
When Thoracic Spine MRI Is Contraindicated

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

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

Other Indications for Thoracic Spine CT
When MRI Is Contraindicated or Cannot Be Performed

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^28,29,30
• Known Arnold-Chiari syndrome (For initial imaging [one-time initial modality assessment] see combination below)
  • Known Chiari I malformation without syrinx or hydrocephalus, follow-up imaging after initial diagnosis with new or changing signs/symptoms or exam findings consistent with spinal cord pathology³¹
  • Known Chiari II (Arnold-Chiari syndrome), III, or IV malformation
• Syrinx or syringomyelia (known or suspected)³²
  • With neurologic findings and/or predisposing conditions (e.g., Chiari malformation, prior trauma, neoplasm, arachnoiditis, severe spondylosis)
  • To further characterize a suspicious abnormality seen on prior imaging
  • Known syrinx with new/worsening symptoms
• Toe walking in a child with signs/symptoms of myelopathy localized to the thoracic spine
• 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

Combination Studies
Brain CT/Cervical Spine CT/Thoracic Spine CT/Lumbar Spine CT (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^{33,34,36,36,37}
• Oncological Applications (e.g., primary nervous system, metastatic)
  • Drop metastasis from brain or spine (CT spine imaging in this scenario is usually CT myelogram) see background
  • Suspected leptomeningeal carcinomatosis (see background)³⁶
  • Tumor evaluation and monitoring in neurocutaneous syndromes
• 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 - CT spine imaging in this scenario is usually CT myelogram)

Cervical Spine and Thoracic Spine CT

• Initial evaluation of known or suspected syrinx or syringomyelia
  • With neurologic findings and/or predisposing conditions (e.g., Chiari malformation, prior trauma, neoplasm, arachnoiditis, severe spondylosis)³²
  • To further characterize a suspicious abnormality seen on prior imaging
  • Known syrinx with new/worsening symptom

Cervical Spine and/or Thoracic Spine and/or Lumbar Spine CTs (Any Combination)
Note: These body regions might be evaluated separately or in combination as documented in the clinical notes by physical examination findings (e.g., localization to a particular segment of the spinal cord), patient history, and other available information, including prior imaging.

Exception: Indications for combination studies^38,39 are approved indications as noted below and being performed in children who will need anesthesia for the procedure

• CT myelogram when meets above guidelines and MRI is contraindicated or for surgical planning
• Post-procedure (discogram) CT

Combination Studies for Malignancy for Initial Staging or Restaging
Unless otherwise specified in this guideline, indication for combination studies for malignancy for initial staging or restaging:

• Concurrent studies to include CT or MRI of any of the following areas as appropriate depending on the cancer: Abdomen, Brain, Chest, Neck, Pelvis, Cervical Spine, Thoracic Spine or Lumbar Spine.

Rationale
Computed tomography is used for the evaluation, assessment of severity, and follow-up of diseases of the spine. Its use in the thoracic spine is limited, however, due to the lack of epidural fat in this part of the body. CT myelography improves the contrast severity of CT, but it is also invasive. CT may be used for conditions, e.g., degenerative changes, infection, and immune suppression, when magnetic resonance imaging (MRI) is contraindicated. It may also be used in the evaluation of tumors, cancer, or metastasis in the thoracic spine, and it may be used for preoperative and post-surgical evaluations. CT obtains images from different angles and uses computer processing to show a cross-section of body tissues and organs. CT is fast and is often performed in acute settings. It provides good visualization of cortical bone.

OVERVIEW
*Conservative Therapy — (Spine) should include a multimodality approach consisting of a combination of active and inactive components. Inactive

• Physician-supervised home exercise program**
• Chiropractic care

Inactive Modalities

• Medications (e.g., NSAIDs, steroids, analgesics)
• Injections (e.g., epidural injection, selective nerve root block)
• Medical Devices (e.g., TENS unit, bracing)

**Home Exercise Program
The following two elements are required to meet conservative therapy guidelines for HEP:⁶

• Documentation of an exercise prescription/plan provided by a physician, physical therapist, or chiropractor; AND
• Follow-up documentation regarding completion of HEP after the required 6-week time frame or inability to complete HEP due to a documented medical reason (e.g., increased pain or inability to physically perform exercises).

Gait and Spine Imaging

Table 1⁴⁸

Contraindications and Preferred Studies

• Contraindications and reasons why a CT/CTA cannot be performed may include: impaired renal function, significant allergy to IV contrast, pregnancy (depending on trimester)
• Contraindications and reasons why an MRI/MRA cannot be performed may include: impaired renal function, claustrophobia, non-MRI compatible devices (such as non- compatible defibrillator or pacemaker), metallic fragments in a high-risk location, patient exceeds wight limit/dimensions of MRI machine

References

36. Wang N, Bertalan M S, Brastianos P K. Leptomeningeal metastasis from systemic cancer: Review and update on management. Cancer. 2018; 124: 21-35. 10.1002/cncr.30911.
37. Radic J A E, Cochrane D D. Choosing Wisely Canada: Pediatric Neurosurgery Recommendations. Paediatr Child Health. 2018; 23: 383-387. 10.1093/pch/pxy012.
38. Utukuri P S, Shih R Y, Ajam A A, Callahan K E, Chen D et al. ACR Appropriateness Criteria® Headache: 2022 Update. Journal of the American College of Radiology. 2023; 20: S70 - S93. 10.1016/j.jacr.2023.02.018.
39. Hayes L L, Palasis S, Bartel T B, Booth T N, Iyer R S et al. ACR Appropriateness Criteria® Headache–Child. Journal of the American College of Radiology. 2018; 15: S78 - S90. 10.1016/j.jacr.2018.03.017.
40. Strahle J, Smith B W, Martinez M, Bapuraj J R, Muraszko K M et al. The association between Chiari malformation Type I, spinal syrinx, and scoliosis. J Neurosurg Pediatr. 2015; 15: 607-11. 10.3171/2014.11.Peds14135.
41. Mbamalu E, Hyacinthe J , Hui A, Tirabady T, Alvandi L. Early Onset Scoliosis and Adolescent Idiopathic Scoliosis: A Review of the Literature and Correlations with Pulmonary Dysfunction. Cureus. 2023; 15: e48900. 10.7759/cureus.48900.
42. Jones J Y, Saigal G, Palasis S, Booth T N, Hayes L L et al. ACR Appropriateness Criteria® Scoliosis-Child. Journal of the American College of Radiology. 2019; 16: S244 - S251. 10.1016/j.jacr.2019.02.018.
43. Trenga A P, Singla A, Feger M A, Abel M F. Patterns of congenital bony spinal deformity and associated neural anomalies on X-ray and magnetic resonance imaging. J Child Orthop. 2016; 10: 343-52. 10.1007/s11832-016-0752-6.
44. Ozturk C, Karadereler S, Ornek I, Enercan M, Ganiyusufoglu K. The role of routine magnetic resonance imaging in the preoperative evaluation of adolescent idiopathic scoliosis. Int Orthop. 2010; 34: 543-6. 10.1007/s00264-009-0817-y.
45. Toader C , Ples H, Covache-Busuioc R, Costin H, Bratu B et al. Decoding Chiari Malformation and Syringomyelia: From Epidemiology and Genetics to Advanced Diagnosis and Management Strategies. Brain sciences. 2023; 13: 10.3390/brainsci13121658.
46. Kadom M, Reddy K, Cooper M, Knight-Scott J , Jones R. Diagnostic Excellence in Pediatric Spine Imaging: Using Contextualized Imaging. Diagnostics (Basel, Switzerland). 2023; 13: 10.3390/diagnostics13182973.
47. Sener U, Kumthekar P, Boire A. Advances in the diagnosis, evaluation, and management of leptomeningeal disease. Neuro-oncology advances. 2021; 3: v86-v95. 10.1093/noajnl/vdab108.
48. Pirker W, Katzenschlager R. Gait disorders in adults and the elderly : A clinical guide. Wien Klin Wochenschr. Feb 2017; 129: 81-95. 10.1007/s00508-016-1096-4.

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, 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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