Magnetic Resonance Imaging and Magnetic Resonance Imaging Cholangiopancreatography of the Pancreas in Small Animals.

Magnetic resonance imaging (MRI) and MR cholangiopancreatography (MRCP) have emerged as non-invasive diagnostic techniques for the diagnosis of pancreatic and pancreatic duct disorders in humans. The number of studies focused on MR and MRCP for pancreatic disease in small animals is very limited. MR has been described for the evaluation of insulinoma in dogs and to investigate pancreatitis in cats. The studies were based on a standard protocol with T2 weighted (w) fast recovery fast spin-echo (FRFSE) with and without fat suppression, T1w FSE pre-contrast and T1w FSE post-contrast with and without fat suppression. MRCP after secretin stimulation has been described in cats to assess the pancreatic ductal system, taking advantage of pulse sequences heavily T2w as rapid acquisition with rapid enhancement (RARE), fast-recovery fast spin-echo (FRFSE) sequences and single-shot fast spin-echo (SSFSE) sequences. In addition to the standard protocol, fast spoiled gradient recalled echo pulse sequences (fSPGR) and volume interpolated 3D gradient-echo T1w pulse sequences pre and post-contrast have also been used in cats, reaching the goal of assessing the biliary tree and the pancreatic duct with the same sequence and in multiple planes. Despite the small amount of data, the results show potential, and the most recent technical innovations, in particular, focused on diffusion MRI and fast acquisition, further support the need for continued evaluation of MRI as an effective instrument for the investigation of pancreatic disease.

Association of magnetic resonance assessed disc degeneration and late clinical recurrence in dogs treated surgically for thoracolumbar intervertebral disc extrusions.

BACKGROUND: Radiographic signs of intervertebral disc mineralization are thought to indicate sites of future recurrence of disc extrusion (Hansen type I) but the relationship between evidence of disc degeneration on magnetic resonance imaging (MRI) and future disc extrusion with recurrence of clinical signs has not been examined. OBJECTIVES: To examine the relationship between MRI-assessed degeneration of thoracolumbar intervertebral discs and late recurrence of clinical signs in dogs presented with acute thoracolumbar intervertebral disc extrusion and treated by hemilaminectomy alone. ANIMALS: Ninety-two client-owned dogs presented to 2 referral hospitals between 2009 and 2014. METHODS: Retrospective analysis of association between clinical signs consistent with recurrent thoracolumbar intervertebral disc extrusion and MRI evidence of disc degeneration in dogs undergoing hemilaminectomy for acute thoracolumbar intervertebral disc extrusion. Univariable and multivariable Cox regression analyses were used to explore associations between recurrence of clinical signs and several characteristics of T10-L3 discs at initial diagnosis. RESULTS: Ninety-two cases were included, of which 42 (46%) were Dachshunds and median age was 5.3 years. Clinical signs recurred in 33/92 (36%) dogs. Finding a completely degenerate disc in the T10 to L3 region (in addition to the operated site) at the time of surgery was associated with a hazard ratio of 2.92 (95% confidence interval: 1.37-6.20) for recurrence of clinical signs. CONCLUSIONS AND CLINICAL IMPORTANCE: Our results suggest that in cases of thoracolumbar intervertebral disc extrusion in dogs, recurrence of signs is likely if at least 1 completely degenerate disc in addition to the currently symptomatic disc is visible on MRI.

Trauma-Associated Pulmonary Laceration in Dogs-A Cross Sectional Study of 364 Dogs.

In this study, we describe the computed tomography (CT) features of pulmonary laceration in a study population, which included 364 client-owned dogs that underwent CT examination for thoracic trauma, and compared the characteristics and outcomes of dogs with and without CT evidence of pulmonary laceration. Lung laceration occurred in 46/364 dogs with thoracic trauma (prevalence 12.6%). Dogs with lung laceration were significantly younger than dogs in the control group (median 42 months (interquartile range (IQR) 52.3) and 62 months (IQR 86.1), respectively; p = 0.02). Dogs with lung laceration were significantly heavier than dogs without laceration (median 20.8 kg (IQR 23.3) and median 8.7 kg (IQR 12.4 kg), respectively p < 0.0001). When comparing groups of dogs with thoracic trauma with and without lung laceration, the frequency of high-energy motor vehicle accident trauma was more elevated in dogs with lung laceration than in the control group. No significant differences were observed between groups regarding tge frequency and length of hospitalization and 30-day mortality. Similar to the human classification scheme, four CT patterns are described in dogs in this study: Type 1, large pulmonary laceration located deeply in the pulmonary parenchyma or around an interlobar fissure; Type 2, laceration occurring in the paraspinal lung parenchyma, not associated with vertebral fracture; Type 3, subpleural lung laceration intimately associated with an adjacent rib or vertebral fracture; Type 4, subpleural lesions not associated with rib fractures. Complications were seen in 2/46 dogs and included lung abscess and collapse.

Computed tomography attenuation value for the characterization of pleural effusions in dogs: A cross-sectional study in 58 dogs.

CT attenuation value can help to differentiate exudate from transudate in people. The aim of this cross-sectional study was to assess the utility of CT in characterizing pleural effusions based on attenuation values in a population of dogs having CT and diagnostic thoracentesis within 48 h of each other. The CT attenuation values were determined using four circular, same size, regions of interest (ROIs) placed on the same CT slice with the greatest quantity of fluid. Values of each ROI were recorded and the mean of the four ROIs mean values (mean of the means) was calculated and considered as the CT attenuation value of that patient. The final population included 23 proper inflammatory exudates, 15 chylous effusions, 12 hemorrhagic effusions and 8 transudates. The median of 'mean of the means' values were: exudate 19.22 HU (8.23 to 37.66 HU); chylous effusion 10.26 HU (-0.90 to 15.37); hemorrhagic effusion 31.65 HU (18.10 to 54.97), and transudate 11.20 HU, (-2.52 to 16.59). CT accurately differentiated hemorrhagic from chylous effusion (AUC 1.0, P < 0.0001) and hemorrhagic effusion from transudate (AUC 1.0, P < 0.0001); CT-values allowed good accuracy in distinguishing exudates from transudates [AUC 0.87 (95%, CI: 0.74-1.0; P < 0.0001)]. HU attenuation values did not accurately differentiate between transudates and chylous effusion. A cutoff value of 34.68 HU (sensitivity of 96% and specificity of 95%) discriminated between exudates and hemorrhagic effusions. CT-value <12.15 HU had a sensitivity of 94% and specificity of 78% for identify transudate or chylous effusion.

Clinical and diagnostic imaging findings in an Italian wolf (Canis lupus italicus) with discospondylitis.

An adult male Italian wolf (Canis lupus italicus) was presented with an abnormal gait. Neurologic examination showed thoracic kyphosis, paraparesis, decreased proprioception in the pelvic limbs, and normal spinal reflexes. Neurologic symptoms suggested a thoracolumbar spinal cord lesion. Pathologic findings included leukocytosis. Spinal radiographs revealed ventral spondylosis of T4/T5/T6, a poorly defined intervertebral disc space, and mild lysis of the vertebral margins. Multiple metallic foreign bodies were seen in the thoracic wall. Magnetic resonance imaging of the spine detected increased signal intensity on fluid sensitive sequences of the vertebral bodies, the intervertebral disc, and surrounding soft tissues. These findings were interpreted as active discospondylitis at T4/T5. Medical therapy included antibiotic and analgesic treatment as well as movement restriction. Follow-up at 4 wk showed significant clinical and radiologic improvement. Discospondylitis should be included in the differential diagnosis in wolves with paresis.

Suspected neurotoxicity due to Clostridium perfringens type B in a tiger (Panthera tigris).

A 4-yr-old tiger (Panthera tigris) was referred with acute onset of severe abnormal consciousness. Neurological evaluation showed normal palpebral and corneal reflexes, normal pupil diameter with normal direct and consensual papillary light reflex, and absent menace response bilaterally. Diffuse forebrain lesion or focal lesion affecting the ascending reticular activating system was suspected. Complete blood examination and cerebrospinal fluid analysis were normal. Magnetic resonance imaging of the brain showed an empty sella as the only result. Clostridium perfringens 10(4) to 10(7) colony-forming units/g were detected in fecal flora samples. Multiplex polymerase chain reaction assay identified serotype B counts with production of epsilon toxin. This toxin specifically accumulates in the central nervous system, where it causes acute neurological signs in humans, domestic animals, and wildlife. In this communication, the acute onset of neurological signs without evidence of trauma, vascular, metabolic, or inflammatory diseases may be caused by neurotoxicity due to C. perfringens.