Affiliation:
1. Department of Otorhinolaryngology‐Head and Neck Surgery University of Maryland Baltimore Maryland U.S.A.
2. Department of Otorhinolaryngology‐Head and Neck Surgery Stanford University Palo Alto California U.S.A.
3. School of Medicine Stanford University Palo Alto California U.S.A.
4. Department of Radiology Stanford University Palo Alto California U.S.A.
Abstract
ObjectiveThe short T2 nature of cortical bone causes it to appear similar to air on MR, forcing clinicians to rely on computed tomography imaging, with its attendant ionizing radiation exposure, to define temporal bone structures. Through the use of novel MR sequences with ultra‐short echo times (UTE), short T2 structures are now able to be visualized, allowing for improved understanding of anatomical relationships.MethodsEight patients (50% female) undergoing MR imaging of the skull base for diagnostic purposes (62.5% for vestibular schwannoma surveillance) at a tertiary care center were enrolled to evaluate the safety and efficacy of UTE imaging. CT scans were completed in 37.5% of the patients as part of their workup and used for comparison purposes. The repetition time, short echo time, and long echo time for the UTE sequence were 11, 0.032, and 2.2 msec, respectively.ResultsThe protocol added 6 min to the total scanning time, and all patients tolerated the sequence without issue. The ossicles, mastoid air cells, antrum, and epitympanum were able to be seen and had a high Dice similarity coefficient when compared to CT (>0.5). UTE allowed for clear delineation of all segments of the facial nerve with a signal‐to‐noise ratio of 35 (although the BRAVO sequences had a superior ratio of 140). Vestibular schwannomas were able to be distinguished from normal brain parenchyma.ConclusionsUTE is safe and effective for visualizing anatomic structures not normally seen on traditional MRI, potentially allowing for improved surgical planning in patients.Level of EvidenceIII Laryngoscope, 2024