The CT contrast crisis calls for more use of MRI and ultrasound

A team led by Dr. Timothy Fiore of Fiona Stanley Hospital in Perth, Australia writes that a significant shortage of any key substance used in patient care requires an immediate and flexible response. Health departments and imaging providers there quickly evaluated the use of CT contrast and developed new procedures to preserve it.

“Strategies include the use of alternative imaging methods to answer clinical questions, weight-based contrast dosing, and low kVp CT protocols to improve clarity of iodinated contrast media,” the group explained.

The lack of iodinated contrast is due in large part to a May closing of Shanghai, China Aiming to avoid a COVID-19 outbreak; The closure prevented GE Healthcare’s ability to dispense the Omnipaque contrast agent. The crisis was mostly resolved by June, but healthcare providers around the world warn that vulnerabilities in the supply chain for materials such as contrast agents persist and must be addressed.

To this end, Fiori and colleagues identify the following best practices for head and neck imaging to provide a framework for maintaining contrast in acute care settings.

  • Thyroid: Symptomatic thyroid nodules can be identified on carotid Doppler ultrasound, chest computed tomography, or positron emission tomography/computed tomography; Ultrasound helps doctors determine whether a patient would benefit from fine-needle aspiration. Hyperthyroidism can be treated with thyroid scintigraphy, and goiter can be imaged using computed tomography without contrast.
  • salivary glands: The group wrote that blockages and masses of these glands can be evaluated with ultrasound. Ultrasound findings may indicate that CT or MRI scans will be useful to further work on larger or malignant lesions. Computed tomography provides clinical data regarding bone involvement in salivary gland diseases but can be performed without contrast with this indication.
  • Pediatrics: For neck masses, ultrasound is again the first imaging method to describe the mass. If malignancy is suspected, MRI or contrast-enhanced CT may be used. CT is recommended if orbital, temporal or intracranial diseases are suspected. Finally, for children with stridor, the first line of diagnosis is laryngoscopy or bronchoscopy, but contrast CT is recommended in more serious cases.
  • Stages of head and neck cancer: The researchers wrote that MRI is the go-to method for staging head and neck cancer, although non-contrast CT is a useful alternative. CT compared to MRI is recommended for staging tumors in the larynx and hypopharynx because patients with these conditions may have a damaged airway and CT exams are shorter than MRI exams.

The bottom line is that MRI and ultrasound are useful alternatives to contrast-enhanced CT for head and neck abnormalities, according to the authors.

They concluded, “For routine assessment of blunt head and neck presentations in children and adults, the use of contrast-enhanced CT can be safely minimized or avoided, to preserve iodinated contrast media.” “This can be achieved through… the use of alternative modalities [such as] Ultrasound and MRI, [which] The iodinated contrast media not only preserves but also avoids ionizing radiation.”

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