The potential role of magnetic resonance brain relaxometry in veterinary medicine: a preliminary study.

Magnetic Resonance (MR) is a non-invasive modality of choice for the evaluation of brain morphology, with superior performance as compared to other techniques. However, MR images are typically assessed qualitatively, thus relying on the experience of the involved radiologist. This may lead to errors of interpretation in the presence of subtle alterations and does not exploit the full potential of this technique as a quantitative diagnostic tool. To this end Magnetic Resonance Relaxometry (MRR), which is able to quantitively characterize the tissues under investigation through their relaxation rates, seems extremely promising. Many studies assessed the feasibility of relaxometry as a diagnostic tool in human brain disorders, with the most promising results obtained in the evaluation of neurodegenerative diseases and in the oncologic field. However, despite such extensive literature in human medicine, due to the lack of standardized protocols and the need of high-field MRI scanners, to date few studies have been performed on companion animals. In this work, first we describe relaxometry applications in human neuropathology and their possible extension to companion animals both in the experimental and clinical fields. Then, we present two experiments performed on a typical standard clinical scanner operating at 0.25 T to show that, despite the low field intensity, this technique may be promising even in the clinical setup. We tested the relaxometry protocol in a phantom study and then applied it to a real clinical case study. The results showed that this protocol used on a phantom led to a higher contrast, as compared to the standard approach. Furthermore, when applied to a real case study, this protocol revealed brain lesions undetected by the standard technique which were confirmed by a histopathological examination. These preliminary results are encouraging and support the development of this approach as an advanced diagnostic tool even in a clinical setting where low field MRI scanners are typically employed.

Diffuse Pulmonary Adenocarcinoma with Micropapillary Growth Pattern in a Cat.

A 12-year-old female European shorthair cat was presented with severe dyspnoea. Echocardiography revealed hypertrophic cardiomyopathy and pleural effusion. The cat died from acute decompensated left heart failure. At necropsy examination, the lungs were diffusely congested and firm, with multifocal grey areas and sparse haemorrhages. No solid masses were detected. Histopathology revealed a diffuse neoplastic proliferation characterized by irregular growth along alveolar walls with a micropapillary pattern. Tumour cells were large, highly pleomorphic and intensely positive for pan-cytokeratin and CAM 5.2. Tumour growth was obscured by simultaneous lesions related to chronic pulmonary congestion and interstitial lung disease. Histological features were consistent with a diffuse invasive pulmonary adenocarcinoma with a micropapillary pattern of tumour growth. Differential diagnosis included large cell carcinoma, which is usually characterized by rosettes or solid clusters of cells occupying alveolar lumen. Extensive cytokeratin immunolabelling was helpful in the differentiation from histiocytic proliferative disease.

Prognostic factors for survival in dogs with pituitary-dependent hypercortisolism treated with trilostane.

Pituitary-dependent hypercortisolism (PDH) is one of the most frequent endocrinopathies in dogs, but prognostic factors are largely unknown. The aim of this retrospective case series study was to determine the prognostic value of different clinical and clinicopathological variables evaluated in dogs newly diagnosed with PDH that were subsequently treated with trilostane. Medical records from one referral centre were evaluated. Eighty-five dogs with PDH were included. The median survival time was 852 days (range 2-3210 days); 60/85 (70 per cent) and 25/85 (29 per cent) dogs survived more than one and three years, respectively. In multivariable model analysis the length of survival of older dogs (HR 1.24, 95% CI 1.09 to 1.40) and dogs with higher serum phosphate concentrations (HR 1.35, 95% CI 1.01 to 1.81) was shorter. Serum phosphate concentrations were above the reference range in 37/85 (44 per cent) of animals. Clinical signs, liver enzymes, serum cortisol concentrations of the endocrine tests, proteinuria, systolic hypertension, the presence of concomitant disorders, and the frequency of trilostane administration were not associated with survival time. Hyperphosphataemia is a common finding in dogs with newly diagnosed PDH and represents a negative prognostic factor.

Type 1 diabetes mellitus and hyperadrenocorticism in a ferret.

Diabetes mellitus (DM) was diagnosed in a 6-year-old neutered male ferret with polyuria/polydipsia, symmetrical alopecia, and weight loss. Laboratory tests revealed severe hyperglycemia, glucosuria, and increased steroid hormone profile. Abdominal ultrasound revealed a bilateral enlargement of the adrenal glands. Significant clinical improvement was achieved with insulin- and leuprolide acetate-based therapy. After 2 months of therapy, the ferret showed a severe ketoacidosis, and the owner decided to euthanize the animal. Histological findings revealed carcinoma of the left adrenal cortex and cortical hyperplasia of the right adrenal gland. Moderate, chronic, and active pancreatitis with a marked decrease in the number of beta-cells was also present. This is the first reported case of type 1 DM associated with hyperadrenocorticism and chronic pancreatitis in a ferret.

Evaluation of a portable meter to measure ketonemia and comparison with ketonuria for the diagnosis of canine diabetic ketoacidosis.

BACKGROUND: The diagnosis of canine diabetic ketoacidosis (DKA) usually is based on measurement of urinary acetoacetate (ketonuria). In humans, this test is less sensitive and specific than blood 3-beta-hydroxybutyrate (ketonemia) evaluation. HYPOTHESIS: Ketonemia measurement using a portable meter is more accurate than ketonuria determination with a dipstick to diagnose canine DKA. ANIMALS: Seventy-two client-owned diabetic dogs with ketonemia, ketonuria, or both. METHODS: Prospective observational study. Based on blood bicarbonate concentration and anion gap, dogs were divided into 2 groups: patients with DKA (n= 25); patients with diabetic ketosis (n= 47). Sensitivity, specificity, and positive and negative likelihood ratio (LR) at different cut-off points were determined for both ketonemia and ketonuria. Receiver operating characteristic (ROC) analysis was used to assess the accuracy of each diagnostic test to diagnose DKA. RESULTS: With regard to ketonemia, cut-off values of 2.3 and 4.3 mmol/L revealed 100% sensitivity and 100% specificity, respectively, whereas cut-off values of 2.8 and 3.5 mmol/L showed a -LR of 0.05 and a + LR of 13.16, respectively. With regard to ketonuria, a cut-off value of 1+ revealed 92% sensitivity, 40% specificity, and -LR of 0.20, whereas a cut-off value of 3+ revealed 44% sensitivity, 94% specificity, and +LR of 6.89. The areas under the ROC curves for the ketonemia and ketonuria tests were significantly different (0.97 and 0.81, respectively, P= .003). CONCLUSIONS AND CLINICAL IMPORTANCE: Measurement of ketonemia is accurate and more effective than measurement of ketonuria to diagnose canine DKA.