From the Guidelines
A contrast-enhanced CT of the head and neck is the preferred initial imaging modality for a palpable nonpulsatile neck mass in an adult, particularly considering the risk of head and neck cancer. This recommendation is based on the American College of Radiology's (ACR) appropriateness criteria for neck mass-adenopathy, as outlined in a 2019 study published in the Journal of the American College of Radiology 1. The use of contrast-enhanced CT allows for superior spatial resolution, which is essential for identifying abnormal lymph nodes and guiding the search for an unknown primary malignancy.
When it comes to imaging protocols, dual-phase CT imaging (without and with IV contrast) is not usually necessary, and CT performed only without IV contrast may be helpful in some cases 1. Additionally, advances in lower dose protocols and reconstruction algorithms can help minimize radiation exposure, and all imaging should reflect "as low as reasonably achievable" (ALARA) practices.
The benefits of CT scans in evaluating head and neck conditions include:
- Identifying a dental source of infection in febrile patients
- Evaluating the extent of deep neck inflammation, which may be superior to ultrasound (US)
- Confirming fat-containing lesions in the neck using CT Hounsfield units
- Providing superior bone detail compared to MRI, making it particularly valuable in emergency situations
Overall, a contrast-enhanced CT of the head and neck is a valuable diagnostic tool for evaluating a range of conditions, from suspected tumors and infections to structural abnormalities and trauma, and its use should be guided by the most recent and highest-quality evidence, such as the ACR's appropriateness criteria 1.
From the FDA Drug Label
Intra-arterial Procedures (1. 1) Adults: Cerebral Arteriography (300,320 mg iodine/mL) Intravenous Procedures (1. 2) Adults: Computed tomography (CT) Imaging of Head and Body (300,320,350 mg iodine/mL)
The ioversol (IV) is indicated for CT Imaging of the Head.
- The approved concentrations for this use are 300,320,350 mg iodine/mL.
- This information is based on the drug label for ioversol (IV) 2
From the Research
CT Head and Neck Imaging
- CT head scans are commonly used to provide an overview of the brain and its surrounding structures, particularly in trauma settings 3.
- The scan can confirm or exclude intracranial haemorrhage, skull fracture, or stroke in a matter of seconds 3.
Risk of Acute Kidney Injury
- The use of iodinated contrast-enhanced CT imaging may pose a risk of renal injury, including acute kidney injury (AKI) 4, 5, 6, 7.
- Studies have shown that the incidence of AKI in patients undergoing CT stroke studies and digital subtraction angiography (DSA) is relatively low, ranging from 4.7% to 10.2% 4, 7.
- The use of multimodal CT imaging and intra-arterial treatment has been found to be safe in terms of renal safety, with no significant differences in mean serum creatinine or rates of AKI compared to intravenous treatment 6.
Contrast-Associated Acute Kidney Injury
- Concerns remain regarding contrast-associated acute kidney injury (CA-AKI) in patients receiving multi-dose iodinated contrast 7.
- However, studies have found no significant association between multi-dose iodinated contrast and CA-AKI in acute ischemic stroke patients 7.
- Factors such as diabetes mellitus, operation duration, and times of embolectomy may be predictors of creatinine increase and AKI 6.