A New Frontier in Temporal Bone Imaging: Photon-Counting Detector CT Demonstrates Superior Visualization of Critical Anatomic Structures at Reduced Radiation Dose

Pöschl reformatted images in a patient with superior semicircular canal dehiscence, shown on EID-CT (left) and PCD-CT (right) images. The PCD-CT image (B) clearly demonstrates 2 discrete regions of dehiscence (curved arrows). These regions are also identifiable on conventional EID-CT (A), though the intact adjacent bone is less well-visualized. The integrity of the roof of the superior semicircular canal was not formally evaluated in the readers’ study but is shown for illustrative purposes.

Ossicular anatomy, shown on conventional EID-CT (upper row) and PCD-CT (lower row). Reformatted images along the plane of the tensor tympani (A and E) demonstrate the tensor tympani (TT) extending to the upper handle of the malleus (HA); the lateral process (L) of the malleus is also clearly visible. An image reformatted along the long plane of the malleus (B and F) shows its handle (HA), lateral process (L), neck (N), and head (H). An image reformatted along the length of the stapes (C and G) clearly demonstrates the suprastructure (SS) and both crura. A “molar tooth” reformatted image (D and H) shows the HA of the malleus, as well as the body (B) and long process (LP) of the incus. These additional reformatted images were generated by a nonreviewer radiologist to demonstrate certain anatomic features but were not used by the readers to score image quality.

The incudostapedial joint (arrows), shown on EID-CT (left) and PCD-CT (right) images. The joint was one of several anatomic structures specifically graded using a 5-point Likert score, with higher scores favoring the quality of the PCD-CT images. The images reformatted in this plane were generated by a nonreviewer radiologist to demonstrate certain anatomic features but were not used by the readers to score image quality.

A stapes piston prosthesis shown on EID-CT (upper row) and PCD-CT (lower row) images. The prothesis is shown on oblique axial (A and C) and oblique coronal (B and D) reformats along the plane of the piston. In both planes, the stapes prosthesis was better delineated on PCD-CT due to reduced partial volume averaging from 0.2 mm sections. These additional reformatted images were generated by a nonreviewer radiologist to demonstrate certain anatomic features but were not used by the readers to score image quality.