In general, the higher the number of detector rows employed by a particular MDCT scanner, the more isotropic the voxel size and the greater the resolution of the MPRs. All MPR images included in this chapter were reconstructed from volumetric data sets acquired on a 64-slice MDCT yielding a voxel size of 0.4 mm³. Supplemental short axis (Pöschl) and long axis (Stenvers) MPR volumes can be routinely reconstructed at the CT console using the previously mentioned anatomic landmarks at the request of the interpreting radiologist. Any additional targeted MPRs are reconstructed from the volumetric data set at a separate workstation, preferably one that is capable of producing MPRs using at least two independent planes of obliquity.

Long axis MPRs and maximum intensity projections (MIPs) of the ossicles can be useful in assessment of ossicular integrity (Bin et al. 2008). In the clinical setting of conductive hearing loss. Chronic inflammatory disease with or without cholesteatoma, temporal bone fracture, or congenital anomalies such as aural atresia or microtia can produce various ossicular pathologies to include fixation, erosions, and disarticulations. Since the standard axial and coronal orientations do not display the ossicles to best advantage, the integrity of the ossicular chain can be confirmed with long axis MPRs of each individual ossicle (Figs. 3, 4, 5). Occasionally MPRs in the plane of the short axis of the stapes can be useful, particularly in the setting of stapes footplate fixation secondary to early otospongiotic plaque along the anterior edge of the oval window in the vicinity of the fissula ante fenestram (Fig. 6).

An oblique sagittal MPR can be employed to profile the incudomalleolar joint and at the same time inspect the integrity of the manubrium of the malleus and long process of the incus, recreating the old “Molar Tooth” tomographic appearance (Fig. 7). Since the malleus and incus differ slightly in their lateral to medial angulation, a 2–3 mm MIP in the oblique sagittal plane can be quite helpful in producing a more complete assessment of these ossicles (Fig. 7c). This perspective can be useful in confirming any suspicion of malleoincudal luxation seen on axial or coronal images in patients with conductive hearing loss following trauma (Fig. 7e, f). Erosions of the long process of the incus, a relatively common complication of middle ear inflammatory disease, can be nicely demonstrated in this plane with both MPR and MIP images (Fig. 7g, h). Additionally, Pöschl plane reconstructions of the ossicles provide an ideal depiction of both the incudomalleolar and incudostapedial articulations (Fig. 8). Pöschl MPR and MIP images can be useful in confirming incudostapedial disarticulation following trauma or as a result of chronic inflammatory disease (Fig. 8d).