When to Order Imaging for Tinnitus: ACR Appropriateness Decoded

When to Order Imaging for Tinnitus: ACR Appropriateness Decoded

It’s late in your shift, and you’re evaluating a patient with a persistent ringing in their ear. Is it a benign annoyance or a sign of something more serious, like a vascular anomaly or a tumor? The patient is anxious, and you need to decide on the next steps. Do you order a Computed Tomography (CT) scan, a Magnetic Resonance Imaging (MRI), or an angiogram? Choosing the right initial imaging study is critical for accurate diagnosis, cost-effectiveness, and minimizing unnecessary radiation exposure. This guide breaks down the American College of Radiology (ACR) Appropriateness Criteria for tinnitus, providing clear, evidence-based recommendations to help you make the right call with confidence.

What Does the ACR Guidance for Tinnitus Cover?

The ACR Appropriateness Criteria for tinnitus focus on the initial imaging workup for adult and pediatric patients presenting with this common symptom. The guidelines are stratified based on key clinical features that point toward different underlying pathologies. The primary distinction is between pulsatile tinnitus (a rhythmic sound in sync with the patient’s heartbeat, suggesting a vascular cause) and nonpulsatile tinnitus (a constant ringing, hissing, or buzzing, often associated with sensorineural or structural causes).

These criteria apply to patients with either unilateral or bilateral symptoms. However, they are specifically designed for initial evaluation and do not cover follow-up imaging or tinnitus related to acute trauma, sudden sensorineural hearing loss, or known auditory pathway pathology. The recommendations are tailored to specific clinical scenarios, such as the presence of a retrotympanic lesion on otoscopy or associated neurologic deficits, which significantly alter the imaging algorithm.

What Imaging Should I Order for Tinnitus? Recommendations by Clinical Scenario

The optimal imaging strategy for tinnitus depends entirely on the clinical presentation. The ACR provides distinct pathways for pulsatile versus nonpulsatile symptoms, with further branching based on physical exam findings.

For a patient with pulsatile tinnitus (unilateral or bilateral) and no retrotympanic lesion on otoscopy, the primary goal is to evaluate for vascular causes like arteriovenous fistulas, aneurysms, or vascular stenosis. In this context, several studies are rated as Usually appropriate. These include MRA head with IV contrast, MRI head and internal auditory canal without and with IV contrast, and both CTA head and neck with IV contrast and CTA head with IV contrast. The choice between MRA and CTA often depends on institutional preference, scanner availability, and patient factors like renal function or contraindications to MRI. Non-contrast MRA and MRI may be appropriate but are generally less sensitive for the full range of vascular pathologies.

The imaging choice changes significantly if the patient has pulsatile tinnitus with a suspected retrotympanic lesion on otoscopy. This finding strongly suggests a middle ear mass, such as a glomus tumor or an aberrant carotid artery. Here, the ACR rates CT temporal bone without IV contrast as Usually appropriate. This study provides exquisite bony detail of the middle ear and temporal bone, which is ideal for characterizing these types of lesions. Vascular studies like CTA may be appropriate as a secondary step if a vascular mass is confirmed or suspected.

For nonpulsatile tinnitus that is unilateral (and without hearing loss, neurologic deficit, or trauma), the main concern is a retrocochlear pathology like a vestibular schwannoma. The ACR clearly recommends MRI head and internal auditory canal without and with IV contrast as Usually appropriate. This is the gold standard for visualizing the vestibulocochlear nerve and cerebellopontine angle. A non-contrast MRI may be appropriate in some cases, but the addition of gadolinium significantly increases sensitivity for small tumors.

In contrast, for patients with bilateral nonpulsatile tinnitus and an otherwise normal neurologic and otologic exam, the likelihood of a structural cause is very low. Consequently, the ACR rates all imaging modalities as Usually not appropriate. In these cases, tinnitus is most often idiopathic or related to presbycusis or noise exposure, and imaging is unlikely to yield a clinically significant finding.

ACR Imaging Recommendations Table for Tinnitus

Adult vs. Pediatric Tinnitus Imaging: Radiation Dose Tradeoffs

While tinnitus is less common in children, the principles of imaging selection still apply, but with a heightened focus on radiation safety. The As Low As Reasonably Achievable (ALARA) principle is paramount in pediatric imaging due to children’s increased radiosensitivity and longer life expectancy, which allows more time for potential long-term effects of radiation to manifest. For tinnitus evaluation, MRI and MRA are strongly preferred in children whenever clinically appropriate, as they involve no ionizing radiation (0 mSv).

When a CT-based study like a CTA is necessary for evaluating suspected vascular pathology, pediatric protocols are adjusted to minimize the dose. The ACR guidelines reflect this, often showing a higher relative radiation level (RRL) symbol for pediatric CTA (☢ ☢ ☢ ☢) compared to adults (☢ ☢ ☢), even if the absolute mSv range is similar. This highlights the greater relative risk. For instance, a CTA of the head and neck carries an RRL of ☢ ☢ ☢ (1-10 mSv) for adults but ☢ ☢ ☢ ☢ (3-10 mSv) for children. This underscores the importance of justifying any radiation-based study in a pediatric patient and ensuring the protocol is optimized for their size and age.

Imaging Protocol Details for Tinnitus

Once you’ve decided on the right study based on the clinical scenario, ensuring it is performed correctly is the next critical step. The specific imaging protocol—including slice thickness, field of view, and contrast timing—can make the difference in identifying subtle pathology. Our detailed protocol guides cover the technical specifications and interpretation pearls for the key studies recommended in these guidelines.

• MRA Brain Without Contrast (3D TOF)
• CT Brain Without Contrast
• US Carotid Doppler

Tools to Help You Order the Right Study

Navigating imaging guidelines can be complex, especially when dealing with nuanced clinical presentations. GigHz offers several tools designed to support evidence-based decision-making at the point of care.

For scenarios beyond tinnitus, the ACR Appropriateness Criteria Lookup provides a searchable interface to find the latest ACR recommendations for hundreds of clinical variants. This helps ensure you’re always aligning your orders with expert panel consensus.

To explore the technical details of the studies themselves, the Imaging Protocol Library offers in-depth guides on how specific CT and MRI scans are performed, which is particularly useful for trainees and non-radiologists seeking to understand the tests they are ordering.

When ordering studies that involve ionizing radiation, especially for pediatric patients or those with a history of multiple scans, the Radiation Dose Calculator can help estimate and track cumulative exposure. This is an invaluable tool for patient communication and adhering to the ALARA principle.

Why is imaging generally not recommended for bilateral nonpulsatile tinnitus?

For bilateral, nonpulsatile tinnitus in a patient with a normal neurologic exam and no hearing loss, the pre-test probability of finding a structural cause (like a tumor or vascular lesion) is extremely low. This type of tinnitus is most commonly associated with systemic or sensorineural causes such as presbycusis (age-related hearing loss), noise-induced hearing loss, or ototoxic medications. Since imaging is unlikely to identify these causes or alter management, the ACR panel has determined that the potential risks, costs, and incidental findings from imaging outweigh the benefits.

What is the main difference between CTA and MRA for evaluating pulsatile tinnitus?

Both CTA (Computed Tomography Angiography) and MRA (Magnetic Resonance Angiography) are excellent for visualizing blood vessels, but they use different technologies. CTA uses X-rays and iodinated contrast to create detailed 3D images, offering superb spatial resolution, especially for bony anatomy and vessel walls. It is fast and widely available. MRA uses powerful magnets and radio waves, and can be performed with or without gadolinium-based contrast. It avoids ionizing radiation and provides excellent soft tissue contrast, but it is more susceptible to motion artifact and has more contraindications (e.g., certain implants). The choice often depends on the specific suspected pathology, patient factors (like renal function), and institutional expertise.

When is a CT of the temporal bone the best first choice for tinnitus?

A CT of the temporal bone is the best initial imaging test when a patient presents with pulsatile tinnitus and the physical exam (otoscopy) reveals a suspected retrotympanic or middle ear mass. This clinical picture is highly suggestive of pathologies like a glomus tumor (paraganglioma), an aberrant internal carotid artery, or a dehiscent jugular bulb. CT provides unparalleled detail of the bony structures of the middle ear, mastoid, and temporal bone, which is essential for diagnosing and defining the extent of these conditions.

My patient has unilateral tinnitus and asymmetric hearing loss. Do these guidelines apply?

These specific ACR variants for nonpulsatile tinnitus assume no associated hearing loss or neurologic deficits. The presence of unilateral or asymmetric sensorineural hearing loss is a significant red flag for retrocochlear pathology, most notably a vestibular schwannoma (acoustic neuroma). In a patient with both unilateral tinnitus and asymmetric hearing loss, the recommendation for an MRI of the head and internal auditory canals without and with contrast becomes even stronger. While not a distinct variant in this document, it is a classic indication for this study.

What are the key findings to look for on an MRI for unilateral nonpulsatile tinnitus?

The primary target of an MRI for unilateral nonpulsatile tinnitus is the cerebellopontine angle (CPA) and internal auditory canals (IACs). The key finding to look for is an avidly enhancing mass arising from the vestibulocochlear nerve (CN VIII), which is characteristic of a vestibular schwannoma. Other less common findings in the CPA/IAC include meningiomas, epidermoid cysts, or vascular loops compressing the nerve. The exam also evaluates the brainstem, cochlea, and labyrinth for any inflammatory, demyelinating, or other structural abnormalities that could cause the patient’s symptoms.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 12, 2026