Consistent Visualization of the Round Window Niche Veil With Ultrahigh-Resolution Photon-Counting Detector CT.

Objective: To assess whether the ultrahigh-resolution (UHR) mode of photon-counting detector (PCD) CT can consistently visualize the round window niche veil (RWNV) in human ex vivo specimens.

Samples: This ex vivo study was conducted on nine human cadaveric temporal bones (four male and five female body donors) with an average age of 72 years (range of 56-83 yr).

Intervention: Imaging with a dual-source PCD-CT scanner in ultrahigh-resolution (UHR) mode.

Main outcome measures: Two blinded, independent board-certified radiologists reviewed CT images in axial and coronal reformations to determine the presence and extent of an RWNV (complete or partial). The performance of the PCD-CT was evaluated by comparing the readings of the radiologists to inspection of the dissected specimens with a surgical endoscope and microscope.

Results: The UHR mode of PCD-CT provided consistent visualization of the RWNVs. Five out of six RWNVs were accurately identified, and all three specimens without RWNVs were correctly recognized. All complete RWNVs were correctly identified. The readers missed one partial RWNV due to its close proximity and minimal fluid next to the round window membrane. The visualization of the RWNV was superior in the coronal plane compared with the axial plane.

Conclusions: This study is the first to demonstrate that the UHR mode of PCD-CT enables a consistent visualization of the RWNV in ex vivo specimens. The promising results of the current study support verification of the results in prospective patient studies.