- Veterinary View Box
- Posts
- Scoping review-all that is known about MRI characteristics of Brain tumor: so far....
Scoping review-all that is known about MRI characteristics of Brain tumor: so far....
Animals 2024
James L. May ,Josefa Garcia-Mora ,Michael Edwards and John H. Rossmeisl
Background
This scoping review examines the magnetic resonance imaging (MRI) characteristics of brain tumors in dogs and cats. It focuses on qualitative and quantitative imaging features, their diagnostic utility in veterinary practice, and knowledge gaps in neuroimaging for companion animals. The study synthesizes MRI features of common intracranial tumors, such as meningiomas, gliomas, and pituitary tumors, and explores the limitations of MRI in differentiating between tumor types.
Methods
The review followed PRISMA-ScR guidelines and included a systematic search of PubMed and Web of Science from 1995 to 2023. Studies with histopathologically confirmed canine and feline brain tumors and detailed MRI data were included. The authors analyzed lesion morphology, signal intensities across multiple MRI sequences, contrast enhancement patterns, and secondary brain changes. Radiomic data and stakeholder input were also incorporated to evaluate imaging features.
Results
-Lesion Characteristics: MRI features, such as lesion number, location (extra-axial or intra-axial), shape, signal intensity, and contrast enhancement patterns, enable differentiation of brain tumor types.
-Diagnostic Challenges: Similar imaging features among different tumor types and non-tumorous conditions lead to diagnostic uncertainty. Meningiomas, for example, were often misclassified due to overlap in imaging features with other tumors like histiocytic sarcoma or lymphoma.
-Advances in Imaging: Techniques such as diffusion-weighted imaging (DWI) and quantitative analysis (e.g., apparent diffusion coefficient values) have improved diagnostic accuracy, especially for grading gliomas and meningiomas.
-Feline-Specific Data: There is limited research on feline brain tumors compared to canine cases, particularly for rare tumor types.
Limitations
The included studies exhibited significant variability in sample sizes, imaging protocols, and diagnostic standards. The small number of cases in many studies restricted the statistical power and generalizability of findings. Radiomic studies had methodological limitations due to sample imbalances and insufficient validation datasets.
Conclusions
MRI is a valuable diagnostic tool for brain tumors in dogs and cats, offering insights into tumor type and grade. However, its diagnostic specificity and sensitivity are constrained by overlapping imaging features among different conditions. Advanced imaging techniques and standardized protocols are recommended to improve diagnostic accuracy and reduce uncertainty in clinical practice. Further research is needed to enhance the utility of MRI for rare tumor types and to develop robust radiomic models.
MRI features of solitary intra-axial gliomas of dogs and cats (a) and diffusion-weighted imaging appearances of solitary intra-axial lesions that can mimic neoplasms (b). Case 16—canine high-grade, ring-enhancing oligodendroglioma in the temporal and piriform lobes demonstrating the ‘claw-sign’ (arrows), mass effect, transtentorial herniation, and peritumoral edema. Case 17—feline diencephalic high-grade oligodendroglioma. The tumor is heterogeneously T2W/FLAIR hyperintense, T1W hypointense, and ring-enhancing. Case 18—canine low-grade, non-enhancing oligodendroglioma in the parietal lobe displaying the T2-FLAIR mismatch sign. Case 19—canine low-grade, T2W/FLAIR hyperintense, T1W hypointense, non-enhancing astrocytoma in the temporal piriform lobe. Case 20—canine high-grade, contrast-enhancing astrocytoma in the parietal lobe, which demonstrates non-uniform, ring-type enhancement and unrestricted diffusion, manifested as lesion hyperintensity on DWI and ADC images (T2W shine-through). Case 21—canine brain abscess with restricted diffusion (DWI hyperintense and ADC hypointense). Note the rim of T2W hypointensity surrounding the central T2W hyperintense lesion, uniform ring-enhancement of the abscess, and regional meningeal enhancement. Case 22—canine middle cerebral arterial ischemic infarction with restricted diffusion. The lesion is restricted to the cerebrocortical gray matter, is not associated with mass effect, and the parenchymal lesion is non-enhancing. Case 23—canine hemorrhagic brain infarction. The infarct is heterogeneously iso-to hypointense on T2*GRE, is ring-enhancing, associated with significant mass effect, and demonstrates T2W blackout (lesion hypointensity on DWI and ADC) due to susceptibility effects of hemorrhage. On DWI and ADC images, the peripheral hyperintensity surrounding the hypointense lesion core represents perilesional edema.
How did we do? |
Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.