Page 73 - Feline diagnostic imaging

5.1 Diseases of the eline Skull 69

(a) (b) (c)

(d) (e) (f)

(g) (h)

Figure 5.22 Aural neoplasia appearance in CT (a–d) and MR (e–h) images. (a) Transverse postcontrast CT image in a soft tissue window.
A large peripherally enhancing mass has caused osteolysis of the left bulla and expands into the adjacent tissues. (b) CT surface
rendering presents the CT images with a 3‐D perspective. Multifocal areas of osseous proliferation associated with mass can be mapped
in the lateral view of the skull. (c) The mass can also be viewed from a medial perspective, since the left half of the skull can be removed
in the reconstruction. (d) The asymmetric vascularity can also be depicted, more noticeable on the left. With MRI, it is easier to distinguish
the mass margins and regional effects due to superior soft tissue contrast resolution. (e) Transverse T2W MRI image. This ceruminous
gland adenocarcinoma caused osteolysis of the tympanic bulla and medial aspect of the external ear canal. There is infiltration into
longus capitus medially, temporal muscle and calvaria dorsally, and the fascia adjacent to the nasopharynx ventrally. (f) Transverse T1W
MRI image. Extensive calvarial osteolysis is best seen in T1W images (between the irregular lines), but there is also infiltration into the
temporomandibular joint. (g) Postcontrast transverse T1W MRI image of meningeal carcinomatosis. Marked meningeal enhancement is
present in association with the heterogeneously enhancing mass, which was meningeal carcinomatosis. (h) Postcontrast sagittal T1W MRI
image of the same cat shown in Figure 5.21g. The rostrocaudal extent of the lesion is delineated (double‐headed arrow). The destroyed
condylar process of the mandible is seen, since continuation of the bone from the horizontal ramus (*) is not identified. Source: Images
courtesy of Dr Merrilee Holland, Auburn University, and Dr Shannon P. Holmes, Animal Cross‐Sectional Imaging Specialists.

surrounding tissues, cross‐sectional imaging is ideal for 5.1.4 Skull Trauma
evaluation. Alternatively, neoplasia should be considered
in cats presenting with chronic signs of otitis refractory to When traumatized, feline patients frequently incur multi-
treatment and where there is disruption of the ear anat- ple injuries due to motor vehicle accidents, bite wounds,
omy, as this is an uncommon feature of chronic otitis. blunt injury or high‐rise syndrome [88–91]. However, some