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 SELLA CT (1)
Sella CT
When MRI is contraindicated or cannot be performed (2,3)

• For further evaluation of known sellar and parasellar masses
• Suspected pituitary gland disorder ⁽⁴⁾ based on any of the following:
  • Documented visual field defect suggesting compression of the optic chiasm; OR
• • Laboratory findings suggesting pituitary dysfunction ⁽⁵⁾; OR
  • Pituitary apoplexy with sudden onset of neurological and hormonal symptoms; OR
• • Other imaging suggesting sella (pituitary) mass

INDICATIONS FOR TEMPORAL/MASTOID/INTERNAL AUDITORY CANAL CT
Hearing Loss (Documented on Audiogram) (6,7)

• Asymmetric sensorineural when MRI is contraindicated ^(8,9)
• Conductive or mixed ⁽¹⁰⁾
• Congenital ⁽¹⁰⁾
• Cochlear implant evaluation ^{(11,12,13,14)}

Note: For congenital/childhood sensorineural hearing loss suspected to be due to a structural abnormality, CT is the preferred imaging modality for the osseous structures and malformations of the inner ear. MRI is used for evaluating CNVIII, the brain parenchyma, or the membranous labyrinth.

Tinnitus (15,16,17)

• Pulsatile tinnitus with concern for osseous pathology of the temporal bone or a retrotympanic lesion seen on otoscopy
• Unilateral non-pulsatile tinnitus and MRI is contraindicated or cannot be performed

Ear Infection

• Clinical suspicion of acute mastoiditis as a complication of acute otitis media ^{(18,19,20,21)}
  • Systemic illness or toxic appearance
  • Signs of extracranial complications (e.g., postauricular swelling/erythema, auricular protrusion, retro-orbital pain, hearing loss, tinnitus, vertigo, nystagmus)
  • Not responding to treatment

Note: MRI is also indicated if there are signs of intracranial complications (e.g., meningeal signs, cranial nerve deficits, focal neurological findings, altered mental status). This is most common in the pediatric population

• Chronic Otitis Media (with or without cholesteatoma on exam) ^(19,22)
  • Failed treatment for acute otitis media

Cholesteatoma (23,24)

CSF Otorrhea (25,26)

• When looking to characterize a bony defect (for intermittent leaks and complex cases consider CT/MR/Nuclear Cisternography). There should be a high suspicion or confirmatory CSF fluid laboratory testing (Beta-2 transferrin assay)

Temporal Bone Fracture (27,28,29)

• Suspected based on mechanism of injury OR
• Indeterminate findings on initial imaging OR
• For further evaluation of a known fracture for treatment or surgical planning

Vascular Indications (30,31)

• Suspected or known with need for further evaluation
  • Dehiscence of the jugular bulb or carotid canal OR
  • Other vascular anomalies of the temporal bone (i.e., aberrant internal carotid artery, high jugular bulb, persistent stapedial artery, aberrant petrosal sinus)

Peripheral Vertigo (32,33,34)

• Based on clinical exam (Head-Impulse with saccade, Spontaneous unidirectional horizontal nystagmus, Dix-Hallpike maneuver); AND
  • Persistent symptoms after a trial of medication and four weeks of vestibular therapy (e.g., Epley’s maneuvers)

Bell's Palsy/Hemifacial Spasm
If MRI is contraindicated or cannot be performed (for evaluation of the extracranial nerve course):

• If atypical signs, slow resolution beyond three weeks, no improvement at four months, or facial twitching/spasms prior to onset ⁽³⁵⁾

PRE-OPERATIVE/PROCEDURAL EVALUATION
Temporal Bone/Mastoid/Orbit/Sella/Internal Auditory Canal

• Pre-operative evaluation for a planned surgery or procedure

POST-OPERATIVE/PROCEDURAL EVALUATION
Temporal Bone/Mastoid/Orbit/Sella/Internal Auditory Canal

• When imaging, physical, or laboratory findings indicate surgical or procedural complications
• A follow-up study may be needed to help evaluate a patient’s progress after treatment, procedure, intervention, or surgery. Documentation requires a medical reason that clearly indicates why additional imaging is needed for the type and area(s) requested.

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 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)

COMBINATION STUDIES
Brain CT and Orbit CT
If MRI is contraindicated or cannot be performed:

• Optic neuropathy or unilateral optic disk swelling of unclear etiology to distinguish between a compressive lesion of the optic nerve, optic neuritis, ischemic optic neuropathy (arteritic or non-arteritic), central retinal vein occlusion, or optic nerve infiltrative disorders ⁽³⁶⁾
• Bilateral optic disk swelling (papilledema) with vision loss ⁽³⁷⁾
• Approved indications as noted above and being performed in high-risk populations and will need anesthesia for the procedure and there is a suspicion of concurrent intracranial pathology ⁽³⁷⁾

Rationale
Pulsatile tinnitus has many etiologies, and the choice of study should be based on accompanying signs and symptoms. For general screening, MRI brain with IAC/MRA brain and neck is approvable. If IIIH is suspected (typically with headache and vision changes in a younger woman with a high BMI) MRI/MRV brain is indicated. If there is concern for vascular etiology, CTA or MRA brain/neck is indicated. If there is associated hearing loss and neurological signs/symptoms, MRI brain with IAC is indicated. If the temporal bone is suspected to be involved and/or retrotympanic lesion is seen on otoscopy, CT temporal bone/IAC is indicated. If there is concurrent concern for boney and a vascular issue, CTA of the head and neck can be used to evaluate both.

Contraindication 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  

1. Kirsch C. Imaging of Sella and Parasellar Region. Neuroimaging Clin N Am. Nov 2021; 31: 541- 552. 10.1016/j.nic.2021.05.010.
2. Chaudhary V, Bano S. Imaging of the pituitary: Recent advances. Indian J Endocrinol Metab. Sep 2011; 15 Suppl 3: S216-23. 10.4103/2230-8210.84871.
3. Burns J, Policeni B, Bykowski J, Dubey P, Germano I M et al. ACR Appropriateness Criteria® Neuroendocrine Imaging. Journal of the American College of Radiology. 2019; 16: S161 - S173. 10.1016/j.jacr.2019.02.017.
4. Wu L, Li Y, Yin Y, Hou G, Zhu R et al. Usefulness of dual-energy computed tomography imaging in the differential diagnosis of sellar meningiomas and pituitary adenomas: preliminary report. PLoS One. 2014; 9: e90658. 10.1371/journal.pone.0090658.
5. Freda P, Beckers A, Katznelson L, Molitch M, Montori V et al. Pituitary incidentaloma: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. Apr 2011; 96: 894-904. 10.1210/jc.2010- 1048.
6. Cunnane M. Imaging of Tinnitus. Neuroimaging Clin N Am. Feb 2019; 29: 49-56. 10.1016/j.nic.2018.09.006.
7. Sharma A, Kirsch C F, Aulino J M, Chakraborty S, Choudhri A F et al. ACR Appropriateness Criteria® Hearing Loss and/or Vertigo. Journal of the American College of Radiology. 2018; 15: S321- S331. 10.1016/j.jacr.2018.09.020.
8. Krause N, Fink K, Fink J. Asymmetric sensorineural hearing loss caused by vestibular schwannoma: Characteristic imaging features before and after treatment with stereotactic radiosurgery. Radiol Case Rep. 2010; 5: 437. 10.2484/rcr.v5i2.437.
9. Verbist B. Imaging of sensorineural hearing loss: a pattern-based approach to diseases of the inner ear and cerebellopontine angle. Insights Imaging. Apr 2012; 3: 139-53. 10.1007/s13244-011-0134-z.
10. Trojanowska A, Drop A, Trojanowski P, Rosińska-Bogusiewicz K, Klatka J. External and middle ear diseases: radiological diagnosis based on clinical signs and symptoms. Insights Imaging. Feb 2012; 3: 33-48. 10.1007/s13244-011-0126-z.
11. Dewan K, Wippold F 2, Lieu J. Enlarged vestibular aqueduct in pediatric sensorineural hearing loss. Otolaryngol Head Neck Surg. Apr 2009; 140: 552-8. 10.1016/j.otohns.2008.12.035.
12. Joshi V, Navlekar S, Kishore G, Reddy K, Kumar E. CT and MR imaging of the inner ear and brain in children with congenital sensorineural hearing loss. Radiographics. May-Jun 2012; 32: 683-98. 10.1148/rg.323115073.
13. Juliano A, Ginat D, Moonis G. Imaging Review of the Temporal Bone: Part II. Traumatic, Postoperative, and Noninflammatory Nonneoplastic Conditions. Radiology. Sep 2015; 276: 655-72. 10.1148/radiol.2015140800.
14. Ralli M, Rolesi R, Anzivino R, Turchetta R, Fetoni A. Acquired sensorineural hearing loss in children: current research and therapeutic perspectives. Acta Otorhinolaryngol Ital. Dec 2017; 37: 500-508. 10.14639/0392-100x-1574.
15. Cao A, Hwa T, Cavarocchi C, Quimby A, Eliades S et al. Diagnostic Yield and Utility of Radiographic Imaging in the Evaluation of Pulsatile Tinnitus: A Systematic Review. Otology & neurotology open. 2023; 3: e030. 10.1097/ONO.0000000000000030.
16. Jain V, Policeni B, Juliano A F, Adunka O, Agarwal M et al. ACR Appropriateness Criteria® Tinnitus: 2023 Update. Journal of the American College of Radiology. 2023; 20: S574 - S591. 10.1016/j.jacr.2023.08.017.

17. Pegge S, Steens S, Kunst H, Meijer F. Pulsatile Tinnitus: Differential Diagnosis and Radiological Work-Up. Curr Radiol Rep. 2017; 5: 5. 10.1007/s40134-017-0199-7.
18. Kann K. Acute Mastoiditis: Pearls and Pitfalls. March 27, 2016.
19. Patel K, Almutairi A, Mafee M. Acute otomastoiditis and its complications: Role of imaging. Operative Techniques in Otolaryngology-Head and Neck Surgery. 2014/03/01; 25: 21-28. https://doi.org/10.1016/j.otot.2013.11.004.
20. Platzek I, Kitzler H, Gudziol V, Laniado M, Hahn G. Magnetic resonance imaging in acute mastoiditis. Acta Radiol Short Rep. Feb 2014; 3: 2047981614523415. 10.1177/2047981614523415.
21. Bertolaso C, Cammisa I, Orsini N, Sollazzo M, Sardaro V et al. Diagnosing acute mastoiditis in a Pediatric Emergency Department: a retrospective review. Acta bio-medica: Atenei Parmensis. 2023; 94: e2023037. 10.23750/abm.v94i2.13839.
22. Gomaa M, Abdel Karim A, Abdel Ghany H, Elhiny A, Sadek A. Evaluation of temporal bone cholesteatoma and the correlation between high resolution computed tomography and surgical finding. Clin Med Insights Ear Nose Throat. 2013; 6: 21-8. 10.4137/cment.S10681.
23. Baráth K, Huber A, Stämpfli P, Varga Z, Kollias S. Neuroradiology of cholesteatomas. AJNR Am J Neuroradiol. Feb 2011; 32: 221-9. 10.3174/ajnr.A2052.
24. Chen Y, Li P. Application of high resolution computer tomography in external ear canal cholesteatoma diagnosis. J Otol. Mar 2018; 13: 25-28. 10.1016/j.joto.2017.10.004.
25. Hiremath S, Gautam A, Sasindran V, Therakathu J, Benjamin G. Cerebrospinal fluid rhinorrhea and otorrhea: A multimodality imaging approach. Diagn Interv Imaging. Jan 2019; 100: 3-15. 10.1016/j.diii.2018.05.003.
26. Vemuri N, Karanam L, Manchikanti V, Dandamudi S, Puvvada S. Imaging review of cerebrospinal fluid leaks. Indian J Radiol Imaging. Oct-Dec 2017; 27: 441-446. 10.4103/ijri.IJRI_380_16.
27. Collins J, Krishnamoorthy A, Kubal W, Johnson M, Poon C. Multidetector CT of temporal bone fractures. Semin Ultrasound CT MR. Oct 2012; 33: 418-31. 10.1053/j.sult.2012.06.006.
28. Kennedy T, Avey G, Gentry L. Imaging of temporal bone trauma. Neuroimaging Clin N Am. Aug 2014; 24: 467-86, viii. 10.1016/j.nic.2014.03.003.
29. Lantos J, Leeman K, Weidman E, Dean K, Peng T. Imaging of Temporal Bone Trauma: A Clinicoradiologic Perspective. Neuroimaging Clin N Am. Feb 2019; 29: 129-143. 10.1016/j.nic.2018.08.005.
30. Bożek P, Kluczewska E, Misiołek M, Ścierski W, Lisowska G. The Prevalence of Persistent Petrosquamosal Sinus and Other Temporal Bone Anatomical Variations on High-Resolution Temporal Bone Computed Tomography. Medical science monitor: international medical journal of experimental and clinical research. 2016; 22: 4177-4185. 10.12659/msm.898546.
31. Muderris T, Bercin S, Sevil E, Cetin H, Kiris M. A potentially catastrophic anatomical variation: aberrant internal carotid artery in the middle ear cavity. Case Rep Otolaryngol. 2013; 2013: 743021. 10.1155/2013/743021.
32. American College of Radiology. ACR Appropriateness Criteria® Hearing Loss and/or Vertigo. 2018.
33. Muncie H, Sirmans S, James E. Dizziness: Approach to Evaluation and Management. Am Fam Physician. Feb 1, 2017; 95: 154-162.
34. Strupp M, Dieterich M, Brandt T. The treatment and natural course of peripheral and central vertigo. Dtsch Arztebl Int. Jul 2013; 110: 505-15; quiz 515-6. 10.3238/arztebl.2013.0505.

35. Quesnel A, Lindsay R, Hadlock T. When the bell tolls on Bell’s palsy: finding occult malignancy in acute-onset facial paralysis. Am J Otolaryngol. Sep-Oct 2010; 31: 339-42. 10.1016/j.amjoto.2009.04.003.
36. Behbehani R. Clinical approach to opticneuropathies. Clin Ophthalmol. Sep 2007; 1: 233-46.
37. Margolin E. The swollen optic nerve: an approach to diagnosis and management. Pract Neurol. Aug 2019; 19: 302-309. 10.1136/practneurol-2018-002057.

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, Blue Cross Blue Shield Association technology assessment program (TEC) and other non-affiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

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