A Closer Look at Ultrasound and MRI Alternatives for Head and Neck Imaging

Given the recent challenges with supplies of iodinated contrast media (ICM) at various facilities, the authors of a new publication maintain that ultrasound and magnetic resonance imaging (MRI) can be effective imaging options for a variety of head and neck pathology.

In their recently published article in the Journal of Medical Imaging and Radiation Oncology, the authors acknowledged that operator experience and accessibility factor into the use of ultrasound and MRI but maintained that they are safe and viable alternatives for imaging of the neck and head.¹

“Both modalities have the distinct advantage of eliminating radiation exposure and not requiring ICM, certainly making them safer for use in the (pediatric), cancer-predisposed screen population and for surveillance imaging,” wrote study co-author Timothy Fiori, MBBS, who is affiliated with the Department of Medical Imaging at Fiona Stanley Hospital in Perth, Australia, and colleagues.

The article authors pointed out that incidental thyroid nodules are commonly detected on chest computed tomography (CT) or positron emission tomography (PET) CT. However, for subsequent workup of incidental thyroid nodules, the researchers noted a lack of evidence basis for contrast-enhanced computed tomography (CECT). Alternately, thyroid ultrasound, in concert with thyroid function testing, provides an array of benefits, including identification of suspicious sonographic findings that may suggest possible malignancy, according to Fiori and colleagues.

For palpable salivary gland masses, Fiori and colleagues noted that ultrasound is a first-line modality that can help differentiate between extra-glandular nodal disease and intracapsular glandular pathology. While ultrasound is limited in the assessment of perineural disease, deep lobe parotid masses and minor gland involvement, the article authors maintained that it could aid clinicians in ascertaining the need for subsequent MRI or CT imaging for malignant, large, or trans-spatial lesions. In comparison to CECT, Fiore and colleagues said MRI is advantageous for the staging of salivary gland lesions and perineural disease due to enhanced soft tissue resolution.

For neck masses in children, the article authors explained that ultrasound is beneficial in differentiating between vascular anomalies, congenital abnormalities, reactive benign nodal disease, and malignancy.

“(Ultrasound) can accurately characterize the lesion, size and consistency of a presenting focal lesion, differentiate vascular malformations via Doppler interrogation and facilitate FNA (fine needle aspiration) biopsy,” noted Fiori and colleagues.

Referencing 2017 guidelines from the American Academy of Otolaryngology-Head and Neck Surgery, Fiori and colleagues said CECT or neck MRI are recommended first-line imaging for adult neck masses that are deemed to be at risk of malignancy.² Facilitating detailed imaging of the extent and architecture of tumors, MRI helps differentiate between malignant and benign lesions and enables clinicians to have more accuracy with tumor subtyping, according to the article authors. Fiori and colleagues maintained that MRI is “strongly recommended” for diagnosing skeletal-based, paraspinal and indeterminate soft tissue masses.

Noting that ultrasound has been recommended by the United Kingdom Royal College of Radiologists for first-line imaging in confirming soft tissue masses, Fiori and colleagues said the modality shows the vascularity of neck masses, differentiates between solid and cystic masses, and identifies potential issues with structures adjacent to masses.³

References

1. Fiori T, Lisewski D, Flukes S, Wood C, Gibson D. Lessons learnt from the global iodinated contrast media shortage in head and neck imaging. J Med Imaging Radiat Oncol. 2022 Sep 20. doi: 10.1111/1754-9485.13472. Online ahead of print.

2. Pynnonen MA, Gillespie MB, Roman B, et al. Clinical practice guideline: evaluation of the neck mass in adults executive summary. Otolaryngol Head Neck Surg. 2017;157(3):355-71.

3. Smith SE, Salanitri J, Lisle D. Ultrasound evaluation of soft tissue masses and fluid collections. Semin. Musculoskelet Radiol. 2007;11(2):174-91.