Magnetic Resonance Imaging Features of Feline Intracranial Neoplasia: Retrospective Analysis of 46 Cats

Abstract

The purpose of this retrospective study was to determine the magnetic resonance imaging (MRI) characteristics of feline brain tumors and to determine whether these characteristics can be used to accurately predict the histologic diagnosis. MRI scans of 46 cats with histologically confirmed brain tumors were reviewed, including 33 meningiomas, 6 lymphomas, 4 gliomas, 2 olfactory neuroblastomas, and 1 pituitary tumor. MRI features including axial origin, shape, location, signal intensity, contrast enhancement, peritumoral edema, and mass effect were reviewed and characterized for each tumor type. Tumor shape, axial origin, contrast enhancement, and degree of peritumoral edema aided in the identification of tumor type. Meningiomas were always extra-axial and were most often ovoid with marked contrast enhancement and mild peritumoral edema. Gliomas were always intra-axial with ring enhancement and generally caused more peritumoral edema than other tumors. The brain tumor was detected on MRI in 45 (98%) cats. Two blinded independent reviewers correctly identified 82% of all of the tumor types on the basis of MRI appearance alone. Thus, MRI is an excellent diagnostic tool for the detection of brain tumors in cats, and it provides important information to aid in the diagnosis of tumor type.

Advances in Diagnostic and Treatment Modalities for Intracranial Tumors

“…A majority of intracranial tumors in both dogs and cats are hypo‐ to isointense on T1‐weighted imaging, and hyperintense on T2‐weighted imaging. The majority are also contrast enhancing after administration of gadolinium‐based contrast agents 12, 15, 16, 21, 54, 55. A variety of tumor “specific” findings relating to MRI have been reported variably in several studies, some of which are listed below.…”

“…The majority of intracranial tumors in cats are primary, with meningiomas being the predominant type. Lymphoma and pituitary tumors are the most common secondary tumors with other primary and secondary tumors, such as gliomas, occurring at relatively low frequencies compared to dogs 19, 20, 21…”

MRI and clinical resolution of a suspected intracranial toxoplasma granuloma with medical treatment in a domestic short hair cat

“…Furthermore, in all three cases homogenous contrast enhancement of the mass was evident, with contrast extension into the surrounding meninges, creating a dural tail. These imaging features are also typical of those of an intracranial meningioma (Lu and others 2003, Troxel and others 2004). Therefore, cats that present with neurological deficits indicative of a focal brain lesion and where MRI confirms the presence of a mass, a toxoplasma granuloma should be a differential diagnosis, and serological assessment of the toxoplasma titre should be performed prior to pursuing surgical treatment options.…”

Cerebral coenurosis in a cat

“…Depending on the location and size of the cyst, the cyst may be an incidental finding or, when present, clinical signs are attributable to loss of parenchyma (Osborn and Preece 2006). Cystic neoplastic masses should also be considered as a differential diagnosis for a solitary cystic intra-axial lesion, but are uncommon in the cat (Dickinson and others 2000, Troxel and others 2003, Troxel and others 2004). The cystic changes of intra-axial neoplastic masses reported in the cat usually represent necrosis or oedema and are usually irregular and multiple, invariably surrounded by a parenchymal component demonstrating mild to moderate enhancement, and bordered by perilesional oedema (Troxel and others 2004).…”

“…Cystic neoplastic masses should also be considered as a differential diagnosis for a solitary cystic intra-axial lesion, but are uncommon in the cat (Dickinson and others 2000, Troxel and others 2003, Troxel and others 2004). The cystic changes of intra-axial neoplastic masses reported in the cat usually represent necrosis or oedema and are usually irregular and multiple, invariably surrounded by a parenchymal component demonstrating mild to moderate enhancement, and bordered by perilesional oedema (Troxel and others 2004). Therefore for solitary, large, cystic intraparenchymal lesions without peripheral enhancement and without perilesional oedema, suggesting slow progressive enlargement, presenting with signs of ICP on MRI a parasitic larval cyst should be considered the primary differential diagnosis.…”