CT performed only without IV contrast may be helpful in a small number of cases. Bony details (landmarks, erosion, remodeling) and sialoliths are better delineated by CT compared with MRI [74]. Dual phase (without and with IV contrast) is not usually necessary as most sialoliths are not obscured by contrast. A noncontrast CT study is usually not indicated in patients presenting with a neck mass suspected of being a swollen major salivary gland that is due to obstructing sialolith [20]. CT imaging coverage of the entire neck should be considered if full assessment of regional nodes is required. Advances in lower dose protocols and reconstruction vary among vendors [32], and all imaging should reflect ALARA practices [33]. CT perfusion imaging is still a research tool for evaluation of parotid pathology [75,76]. CT Neck Parotid Sialography In the absence of acute infection, CT sialography may provide detailed assessment of the parotid ducts if there is a clinical concern for duct obstruction. CTA Neck There is no evidence to support the use of CTA for evaluation of a parotid region mass. MRI Neck Parotid Sialography Noninvasive MRI sialography may provide assessment of the parotid ducts [88] complementary to anatomic MRI of the face or neck, if there is a clinical concern for acute parotitis in the setting of duct obstruction. MRA Neck There is no evidence to support the use of MRA for evaluation of a parotid region mass. US Neck US is adept at localization of parotid versus extraparotid masses [77,89], and identifying features suspicious for malignancy [90]. Deep lobe lesions are generally not as well delineated with US as in the superficial lobe. Much of the published literature focuses on US-guided fine-needle aspiration, and not the diagnostic utility of US. Contrast-enhanced US and US elastography are newer techniques currently being explored for evaluation of salivary pathology [71,91-94].
Neck Mass Adenopathy. CT performed only without IV contrast may be helpful in a small number of cases. Bony details (landmarks, erosion, remodeling) and sialoliths are better delineated by CT compared with MRI [74]. Dual phase (without and with IV contrast) is not usually necessary as most sialoliths are not obscured by contrast. A noncontrast CT study is usually not indicated in patients presenting with a neck mass suspected of being a swollen major salivary gland that is due to obstructing sialolith [20]. CT imaging coverage of the entire neck should be considered if full assessment of regional nodes is required. Advances in lower dose protocols and reconstruction vary among vendors [32], and all imaging should reflect ALARA practices [33]. CT perfusion imaging is still a research tool for evaluation of parotid pathology [75,76]. CT Neck Parotid Sialography In the absence of acute infection, CT sialography may provide detailed assessment of the parotid ducts if there is a clinical concern for duct obstruction. CTA Neck There is no evidence to support the use of CTA for evaluation of a parotid region mass. MRI Neck Parotid Sialography Noninvasive MRI sialography may provide assessment of the parotid ducts [88] complementary to anatomic MRI of the face or neck, if there is a clinical concern for acute parotitis in the setting of duct obstruction. MRA Neck There is no evidence to support the use of MRA for evaluation of a parotid region mass. US Neck US is adept at localization of parotid versus extraparotid masses [77,89], and identifying features suspicious for malignancy [90]. Deep lobe lesions are generally not as well delineated with US as in the superficial lobe. Much of the published literature focuses on US-guided fine-needle aspiration, and not the diagnostic utility of US. Contrast-enhanced US and US elastography are newer techniques currently being explored for evaluation of salivary pathology [71,91-94].