Computed Tomographic Assessment of Pituitary Gland Dimensions in Domestic Short-Haired Cats

The detection of subtle changes in the pituitary dimensions has relevant clinical implications. In cats, a few studies have established the cut-off values of the pituitary gland's dimensions using small and inhomogeneous samples. The aims of this study were: to determine by computed tomography (CT) the pituitary linear dimensions and the pituitary-to-brain (P:B) ratio in a sample of domestic short-haired (DSH) cats; to assess the effects of sex, age, and weight on pituitary dimensions; and to evaluate the inter- and intra-observer agreement for such measurements. All skull CTs of DSH cats performed over four years using a multidetector CT and a standardized protocol were retrospectively reviewed. The exclusion criteria were: clinical, laboratory, or CT alterations of the pituitary gland, brain diseases, fractures of the neurocranium, and diabetes. The pituitary dimensions and brain area were assessed by two different observers using multiplanar reconstructions and automated segmentation tools. Fifty-one cats were included in the final sample. The intraclass correlation coefficients for intra- and inter-observer reliability were good/excellent, and moderate/good, respectively. No differences between sexes were detected, and negligible correlations were found between age and weight. According to this study, a pituitary gland with a height > 4 mm or a P:B ratio > 0.49 mm should be considered enlarged.

The heart to single vertebra ratio: A new objective method for radiographic assessment of cardiac silhouette size in dogs

Vertebral heart size (VHS) is widely determined in clinical practice as an objective method to assess the cardiac silhouette dimensions. However, a key limitation is that it is difficult to determine VHS in dogs with vertebral alterations. This retrospective, method comparison, observer agreement study sought to overcome this limitation by using the heart-to-single vertebra ratio (HSVR), by evaluating the level of agreement between VHS and HSVR, as well as the intra- and inter-observer agreement for HSVR. Three independent observers retrospectively evaluated thoracic radiographs obtained over a set time period. Exclusion criteria were the presence of alterations of the thoracic spine and the inability to clearly outline the cardiac silhouette. The lengths of the vertebral bodies, from the fourth to eighth thoracic vertebra, and VHS were measured on each radiograph. The HSVR was calculated by dividing the sum of the cardiac long and short axes by the length of each vertebral body. Eighty dogs of different breeds were included in the final analysis. Lin's concordance correlation coefficients revealed strong correlations between VHS and HSVR (0.91-0.96), and the Bland-Altman plots showed low bias (0.01-0.2) between the methods. The mean absolute errors indicated low average magnitudes of error (0.11-0.28). The intraclass correlation coefficients showed good to excellent inter-observer (0.87-0.92; P = 0.000) and intra-observer (0.87-0.99; P < .001) agreement. In the authors' opinion, this new method, which is less time consuming and more objective, could offer a valuable alternative to VHS.

Retrobulbar Filling for Enophthalmos Treatment in Dogs: Technique, Description and Computed-Tomographic Evaluation. Preliminary Cadaveric Study

A new therapeutic approach for enophthalmos may be retrobulbar lipofilling. This study aims to standardize the intraconal filling technique and to evaluate the degree of eyeball displacement by computed tomography (CT). Skull CT was performed on six dog cadavers before and after intraconal injection of two 5% iodinated, viscoelastic solutions, one per eye, using an ultrasound-guided supratemporal approach. The volume to be injected was calculated using formulas for retrobulbar cone anesthesia. After CT, the dogs underwent necropsy and histopathology to evaluate damages that eventually occurred to retrobulbar structures. Eyeball displacement was estimated using two CT-based methods, named M1 and M2. The Wilcoxon signed-rank test revealed no significant difference between the two injected materials in both M1 (p > 0.99), and M2 (lateral p = 0.84 and rostral p = 0.84 displacement). A statistically significant difference was found between the pre- and post-injection group M1 (p = 0.002), M2 (p = 0.004) for the lateral and (p = 0.003) for rostral displacement. Although the slight eyeball displacement, the retrobulbar filling can lead to enophthalmos resolution. Compared to M1, the M2 method has better-defined anatomical landmarks. Further, preclinical in vivo studies are necessary to assess retrobulbar filling efficacy and safety.

Description of a low-cost picture archiving and communication system based on network-attached storage

High costs for installing, maintaining, and updating a standard picture archiving and communication system (PACS) can be prohibitive for small/medium‐sized veterinary facilities. The aims of this prospective, exploratory study were to describe the design, implementation, and author experiences for 1 year's use of a low‐cost PACS based on network‐attached storage. The system described here was easily installed and resiliently stored redundant copies of data. It excellently balanced data recovery, system speed, security, and available memory for storage. A virtual private network also allowed off‐site data review. This system can also be used for future off‐site backup of data in the cloud.

Comparative assessment of hypothalamic-pituitary-adrenal axis suppression secondary to intrabursal injection of different glucocorticoids: a pilot study

BACKGROUND

Hypothalamic-pituitary-adrenal axis (HPAA) suppression is the most common and dangerous, although often unrecognized and untreated, side effect of glucocorticoid administration. The risk and duration depend both on patient and treatment characteristics. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) currently represents the gold standard method to evaluate the metabolism of endogenous and exogenous steroids.

OBJECTIVE

To assess prevalence, severity, and duration of HPAA suppression subsequent to the injection of two steroids with equivalent potency but different pharmacokinetics.

SUBJECTS AND METHODS

Single-blind randomized case-control pilot study. Forty patients (22 F; age 48.7 ± 7.2 years) with shoulder calcific tendinopathy received an intrabursal injection of 40 mg of 6α-methylprednisolone acetate (MA) or triamcinolone acetonide (TA). Just before (T0) and after 1 (T1), 7 (T2), 15 (T3), 30 (T4) and 45 (T5) days, we assessed morning blood cortisol and ACTH by RIA, and 24-h urinary levels of MA, TA and free cortisol by HPLC-MS/MS.

RESULTS

HPAA function was normal at baseline. At T1, all patients presented HPAA suppression reaching the lowest cortisol, ACTH and UFC levels, that were similar between groups. At T2, mean cortisol remained lower than at baseline (p < 0.0001) in the TA group. In both groups, mean cortisol and ACTH levels progressively normalized, suggesting HPA recovery, except for three patients in the MA and two in the TA group. UFC levels remained lower than normal (p < 0.0001) up to T5, despite the disappearance of exogenous GCs. No patient developed manifestations of hypocortisolism.

CONCLUSIONS

A single 40-mg intrabursal injection of MA or TA is sufficient to suppresses HPAA up to 45 days. Although typically asymptomatic, patients should be instructed to recognize and report symptoms suggestive for hypocortisolism, to provide prompt diagnosis, and eventually, treatment, thus avoiding severe complications.