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Updated: Aug 12, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Diffuse cerebral and leptomeningeal astrocytoma in dogs: MR features
S L Kraft1, P R Gavin, C W Leathers
1Department of Veterinary Clinical Medicine and Surgery, College of Veterinary Medicine, Washington State University, Pullman 99164.
Abstract:
Magnetic resonance (MR) imaging has increased sensitivity in detection of nonenhancing brain tumors and may show the extent of CNS neoplasia with greater detail than CT. Magnetic resonance images of the canine brain were acquired in two dogs with diffuse leptomeningeal and cerebral low grade astrocytoma. Abnormalities were identified with MR imaging when CT and CSF analysis were noncontributory. Changes seen with MR included decreased signal on T1-weighted images and increased signal on T2-weighted images consistent with vasogenic edema. Neither MR nor CT showed post-contrast enhancement. Magnetic resonance did not show the full extent of cellular infiltration, however. This was attributed to the diffuse submacroscopic distribution and absence of corresponding edema and contrast enhancement in certain regions of brain.
Insights
Magnetic resonance (MR) imaging detects canine brain tumors better than CT scans when other methods fail. MR imaging showed abnormalities like edema, but not the full tumor extent in these low-grade astrocytoma cases.
Area of Science:
- Veterinary Neurology
- Comparative Oncology
- Neuroimaging
Background:
- Magnetic resonance (MR) imaging offers advanced sensitivity for detecting central nervous system (CNS) neoplasia.
- Computed tomography (CT) and cerebrospinal fluid (CSF) analysis have limitations in diagnosing certain brain tumors.
Observation:
- MR imaging was performed on two dogs with diffuse leptomeningeal and cerebral low-grade astrocytoma.
- Abnormalities were detected via MR imaging when CT and CSF analysis were inconclusive.
Findings:
- MR imaging revealed decreased signal on T1-weighted and increased signal on T2-weighted images, indicative of vasogenic edema.
- Neither MR nor CT demonstrated post-contrast enhancement.
- MR imaging did not fully delineate the extent of cellular infiltration due to submacroscopic distribution and lack of edema or enhancement in some areas.
Implications:
- MR imaging is a valuable tool for diagnosing canine brain tumors, especially when conventional methods are noncontributory.
- The study highlights the limitations of MR imaging in visualizing diffuse, submacroscopic tumor infiltration.
- Further research may explore advanced MR techniques to improve the detection of subtle neoplastic changes in the canine brain.
