Lane, John I.

Purpose of review Photon-counting detector computed tomography (PCD-CT) represents a major technological advancement in computed tomography, offering improved spatial resolution, reduced image noise, and increased dose efficiency compared with conventional energy-integrating detector CT (EID-CT). Because many clinically relevant structures within the temporal bone are submillimeter in size, the temporal bone represents an ideal region for determining whether these technical improvements translate into meaningful clinical benefits. This review evaluates the emerging literature on PCD-CT in temporal bone imaging and examines whether higher spatial resolution meaningfully impacts clinical decision-making. Recent findings Recent studies demonstrate improved visualization of middle ear anatomy, ossicular prostheses, cochlear implant electrode arrays, and superior semicircular canal dehiscence with PCD-CT compared with conventional CT. Improved spatial resolution and reduced metal artifact have been shown to enhance assessment of prosthesis positioning, cochlear duct measurements, and differentiation of true versus near semicircular canal dehiscence. However, given the recent availability of PCD-CT, most studies to date have focused on cadaveric studies, phantom studies, or patient studies evaluating image quality rather than diagnostic accuracy or clinical outcomes. Summary PCD-CT provides substantially improved visualization of submillimeter temporal bone structures and may improve diagnostic confidence in select clinical scenarios. Nevertheless, evidence demonstrating improved clinical outcomes remains limited, and further clinical studies are needed to define the role of PCD-CT in routine temporal bone imaging.

Objective: To describe cochlear implant outcomes in a patient with bilateral rapidly progressive hearing loss secondary to Kelch-like protein–11 (KLHL11) IgG rhombencephalitis. Patient: A 26-year-old male presenting to neurotology clinic at a tertiary care center for evaluation of bilateral rapidly progressive sensorineural hearing loss, unresponsive to systemic corticosteroid therapy. Interventions: Bilateral simultaneous cochlear implantation. Main Outcome Measures: Postimplant speech testing (CNC word, AzBio sentence scoring), and changes to hearing function with fluctuations in systemic disease symptomatology. Results: Preoperative testing demonstrated poor speech perception (bilateral AzBio sentence in quiet: 43%, right-sided CNCw score: 38%, and left-sided CNCw score: 0%). Despite systemic disease progression of KLHL11-IgG rhombencephalitis, including worsening cerebellar ataxia and dysarthria, cochlear implant performance did not decrease at the time of last follow-up. At 1-year, binaural and monaural speech testing were both significantly improved compared with the 1-month testing (bilateral AzBio sentence in quiet: 91%, right-sided CNCw score: 70%, and left-sided CNCw score: 32%). Conclusions: Cochlear implantation may offer meaningful auditory rehabilitation in patients with KLHL11-IgG associated rhombencephalitis with relative auditory nerve sparing, despite ongoing disease progression. Further studies are required to evaluate the durability and generalizability of cochlear implantation across the spectrum of disease-related hearing loss.