RESUMEN
Determining the dimensions of transitional cell carcinomas (TCCs) of the urinary bladder in dogs is important in assessing tumor progression and the response to treatment. The primary aim of this study was to evaluate the reliability of a standardized two-dimensional (2-D) ultrasound (US) protocol performed by a single experienced operator. Secondary aims were to compare World Health Organization (WHO) and Response Evaluation Criteria in Solid Tumors (RECIST) guidelines, and to compare measurements by two operators following these guidelines. These were evaluated by inter-operator and intra-operator reliability using the concordance correlation coefficient (CCC) and Cohen's κ statistics, which demonstrated substantial to better agreement by an experienced operator using either set of guidelines. It was demonstrated that 2-D US provides a reliable means to determine the dimensions of urinary bladder TCC when an experienced operator used a standardized protocol. In a subset of dogs, urinary bladder distension was varied, which resulted in differences in measurement with 2-D US and computed tomography.
Asunto(s)
Enfermedades de los Perros/diagnóstico por imagen , Tomografía Computarizada por Rayos X/veterinaria , Ultrasonografía/veterinaria , Neoplasias de la Vejiga Urinaria/veterinaria , Animales , Carcinoma de Células Transicionales/veterinaria , Enfermedades de los Perros/patología , Perros , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Ultrasonografía/métodos , Neoplasias de la Vejiga Urinaria/diagnóstico por imagen , Neoplasias de la Vejiga Urinaria/patología , Organización Mundial de la SaludRESUMEN
Limited information is available to assist in the ante-mortem prediction of tumor type and grade for dogs with primary brain tumors. The objective of the current study was to identify magnetic resonance imaging (MRI) criteria related to the histopathological type and grade of gliomas in dogs. A convenience sample utilizing client-owned dogs (n=31) with gliomas was used. Medical records of dogs with intracranial lesions admitted to two veterinary referral hospitals were reviewed and cases with a complete brain MRI and definitive histopathological diagnosis were retrieved for analysis. Each MRI was independently interpreted by five investigators who were provided with standardized grading instructions and remained blinded to the histopathological diagnosis. Mild to no contrast enhancement, an absence of cystic structures (single or multiple), and a tumor location other than the thalamo-capsular region were independently associated with grade II tumors compared to higher grade tumors. In comparison to oligodendrogliomas, astrocytomas were independently associated with the presence of moderate to extensive peri-tumoral edema, a lack of ventricular distortion, and an isointense or hyper-intense T1W-signal. When clinical and MRI features indicate that a glioma is most likely, certain MRI criteria can be used to inform the level of suspicion for low tumor grade, particularly poor contrast enhancement. Information obtained from the MRI of such dogs can also assist in predicting an astrocytoma or an oligodendroglioma, but no single imaging characteristic allows for a particular tumor type to be ruled out.
Asunto(s)
Neoplasias Encefálicas/veterinaria , Enfermedades de los Perros/diagnóstico , Glioma/veterinaria , Imagen por Resonancia Magnética/métodos , Animales , Neoplasias Encefálicas/clasificación , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/patología , Enfermedades de los Perros/clasificación , Enfermedades de los Perros/patología , Perros , Femenino , Glioma/clasificación , Glioma/diagnóstico , Glioma/patología , Imagen por Resonancia Magnética/veterinaria , Masculino , Clasificación del Tumor/métodos , Clasificación del Tumor/veterinariaRESUMEN
OBJECTIVE: To assess the ability of a contrast-enhanced magnetic resonance imaging (MRI) technique to quantitatively determine glycosaminoglycan content in canine articular cartilage. METHODS: Fifty-four full-thickness cartilage discs were collected from the femorotibial and scapulohumeral joints of three adult dogs immediately following euthanasia. One set of discs from each dog was analysed for glycosaminoglycan content using a colourimetric laboratory assay. The remaining position-matched set of discs from contralateral limbs underwent pre- and post-contrast gadolinium-enhanced MRI, using repeated saturation recovery pulse sequences which were used to generate calculated T1 maps of the cartilage discs. Linear regression analysis was then performed relating delayed gadolinium-enhanced MRI T1 calculated signal intensity to the cartilage glycosaminoglycan content normalized to DNA content. Repeatability of triplicate measurements was estimated by calculating the coefficient of variation. RESULTS: Mean coefficient of variation estimates for the gadolinium-enhanced MRI T1 signal intensity values for nine sampling sites from three dogs ranged from 5.9% to 7.5%. Gadolinium-enhanced MRI T1 signal intensity was significantly correlated (p <0.05) with normalized glycosaminoglycan content in two dogs (r = 0.79, p = 0.011; r = 0.78, p = 0.048), but not in the third dog (r = 0.53, p = 0.071). CLINICAL SIGNIFICANCE: Gadolinium-enhanced MRI assessment of cartilage may be predictive of glycosaminoglycan content and therefore offer an in vivo assessment of changes in cartilage characteristics over time. Additional studies appear indicated to determine the reliability and clinical applicability of gadolinium-enhanced MRI in detecting changes in cartilage over time.