The vanishing neck mass: how using a laryngeal mask airway during magnetic resonance imaging of a child can cause misdiagnosis

A retrospective study of the impact of supraglottic airway devices on the appearance of neck masses in children undergoing serial magnetic resonance imaging

BACKGROUND

General anesthesia and sedation are used routinely for magnetic resonance imaging (MRI) studies in children to optimize image quality. Airway devices such as supraglottic airways (SGAs) can alter the appearance of cervical soft tissue regions on an MRI and increase the risk of misdiagnosis. This phenomenon has not been well described in vivo.

AIMS

We conducted this retrospective study to determine how often SGAs affected the appearance of neck masses in children who received multiple anesthetics for MRIs with and without an SGA.

METHODS

We retrieved data on children 17 years old and younger who had multiple MRIs between January 2005 and January 2015. Inclusion criteria were patients with neck masses who had a SGA for at least one MRI and either a natural airway or endotracheal tube (ETT) for another MRI. We reviewed MRI images and imaging reports to determine if SGAs affected the appearance of neck masses.

RESULTS

Twelve of the 921 patients who received anesthesia for neck MRIs during the study period met the inclusion criteria. SGAs affected the appearance of the neck mass in 11 of the 12 patients.

CONCLUSIONS

Supraglottic airways can significantly alter the appearance of neck masses in children undergoing MRIs and affect radiologists' ability to assess those masses. Communication with the radiologist prior to the induction of anesthesia is crucial when using supraglottic devices in this patient population. It may be more prudent to use a different airway device and/or anesthetic technique when MRIs of these neck masses are undertaken.