From the Guidelines
For a CT scan of the parotid gland, CT with intravenous contrast is the recommended protocol, as it significantly improves visualization and characterization of parotid lesions. The use of intravenous contrast allows for better differentiation between cystic and solid lesions, mapping of lesion borders, and identification of small primary sites in the upper aerodigestive tract 1. According to the most recent and highest quality study, CT neck with IV contrast is usually appropriate for the initial imaging of parotid region masses 1. Additionally, the American Society of Clinical Oncology recommends imaging with CT or MRI, including intravenous contrast, for patients with suspected salivary gland cancer 1. The benefits of contrast-enhanced CT include improved detection of smaller lesions, evaluation of invasion into surrounding structures, and differentiation between benign and malignant processes. While non-contrast CT may be performed in patients with contraindications to contrast media, it results in a less sensitive and specific examination. Key points to consider include:
- Intravenous contrast improves characterization of parotid lesions
- CT with IV contrast is the recommended protocol for initial imaging of parotid region masses
- Contrast-enhanced CT allows for better detection and evaluation of parotid lesions
- Non-contrast CT may be performed in patients with contraindications to contrast media, but it is less sensitive and specific.
From the Research
CT Scan of Parotid Gland
- The use of contrast in CT scans of the parotid gland is a common practice, as it helps to distinguish between different types of tumors and improves the accuracy of diagnosis 2, 3.
- A study published in 2019 found that contrast-enhanced CT scans with a 50-second scan delay were most effective in distinguishing between Warthin tumors and other types of tumors, including pleomorphic adenomas and malignant tumors 2.
- Another study published in 2021 found that contrast CT scans were useful in evaluating the clinical characteristics and CT findings of parotid and submandibular gland tumors, and that the use of contrast helped to distinguish between benign and malignant tumors 3.
- Earlier studies, such as one published in 1982, found that CT scans without contrast were still useful in diagnosing parotid gland tumors, but that the use of contrast was not necessary for diagnosis 4.
- However, a study published in 1979 found that performing CT scans during contrast sialography helped to show tumors within the parotid gland and their relationship to surrounding structures, including the facial nerve 5.
- More recent research has focused on developing new contrast agents, such as composite iodine-gold nanoparticles, which may improve the accuracy and safety of CT scans 6.