Canine idiopathic orbital inflammation: A case series of four affected dogs (five orbits).

PURPOSE: In humans, idiopathic orbital inflammation (IOI) is a diagnosis attributed to benign, inflammatory orbital conditions without identifiable local or systemic cause. We describe the clinical signs, imaging and histopathological findings, management and outcome of four dogs diagnosed with IOI. METHODS: Multicentric retrospective study. RESULTS: A total of four dogs (five orbits) of three different breeds (three cases were English Springer Spaniels [ESS] or ESS-cross) and ages ranging from 3 to 12 years were included. Initial presenting signs were unilateral and included exophthalmos, enophthalmos, globe deviation, thickening and protrusion of the third eyelid and conjunctival hyperemia. Computed tomography and magnetic resonance imaging identified heterogeneous space-occupying, contrast-enhancing orbital lesions in all cases. Sparing of the retrobulbar space was detected in four of five orbits. Histopathology revealed mixed inflammatory infiltrates of lymphocytes, plasma cells, and histiocytes. Immunohistochemistry was performed in two cases highlighting the presence of histiocytes and lymphocytes, predominantly T cells. Resolution of clinical signs was achieved in two cases managed with oral immunosuppressant medication (corticosteroids alone or combined with cyclosporine or azathioprine), one went into spontaneous remission, one resolved with topical corticosteroids, and one underwent exenteration. Recurrence occurred in two cases within 15 months of initial diagnosis and required further immunosuppressant medication. One case developed signs in the contralateral orbit within 8 months of presentation. CONCLUSIONS: IOI is an uncommon condition in dogs. Its diagnosis relies on the combination of advanced imaging and histology. As in humans, it appears that spontaneous remission and recurrence may occur requiring long-term immunosuppressant medication.

A comparison of cytological quality between fine-needle aspiration and non-aspiration techniques for obtaining ultrasound-guided samples from canine and feline lymph nodes.

BACKGROUND: In small animal medicine, ultrasound-guided fine-needle lymph node sampling plays a pivotal role in the diagnostic investigation of a range of pathologies including the staging of neoplastic disease. Traditionally fine needle aspiration cytology (FNAC) has been employed to produce samples, but fine needle non-aspiration cytology (FNNAC) has been suggested to generate superior sample quality and diagnosticity. METHODS: In a randomised control trial, 104 canine and feline lymph nodes were each sampled by both techniques. The cytological samples were then submitted to pathologists who were blinded to the technique used to generate each sample. They determined if the sample was diagnostic or non-diagnostic and graded the sample in terms of the degree of cellularity, cellular preservation and haemodilution. RESULTS: It was found that lymph node samples obtained using the FNAC technique were more likely to be diagnostic (p = 0.043) than samples obtained using the FNNAC technique. In addition, FNAC samples had significantly higher cellularity than FNNAC counterparts (P = 0.043). No significant difference in cell preservation or haemodilution was found between samples from the FNAC and FNNAC groups. CONCLUSION: In this study, FNAC was superior to non-aspiration cytology for the sampling of canine and feline lymph nodes as it generated a higher number of diagnostic samples with greater cellularity.

Magnetic resonance dacryocystography in the horse: A feasibility study.

OBJECTIVE: To provide a comprehensive anatomical description of the normal equine nasolacrimal duct using magnetic resonance imaging, and to develop a practical protocol for performing magnetic resonance dacryocystography (MRD) in horses. ANIMAL STUDIED: The heads of ten fresh horse cadavers with no history of sinonasal or ophthalmologic disorders were used for this study. PROCEDURE: An MRD technique was developed in this study, which consisted of two parts. In the first part, olive oil and gadolinium were compared as contrast medium, using five horses. Two concentrations of gadolinium were used: 0.25 mmol/mL and 0.5 mmol/mL. In the second part, the influence of different head recumbencies using olive oil as the sole contrast medium was studied in the remaining five horses. RESULTS: Injection with olive oil resulted in better distention and a complete filling of the nasolacrimal duct (ND) in all horses. Injection of 0.25 mmol/mL of gadolinium resulted in incomplete filling of the ND, whereas injection of 0.5 mmol/mL of gadolinium resulted in slightly better filling of the duct. The nondependent duct showed better distention compared to the dependent duct when scanning in lateral recumbency. No differences were observed between ducts in a dorsal recumbency. The degree of distention in dorsal recumbency was slightly less than the degree of distention observed in the nondependent ND in lateral recumbency. CONCLUSIONS: Magnetic resonance dacryocystography is a suitable technique for evaluating the nasolacrimal duct and can be performed during a normal magnetic resonance examination.

Ultrasound of the normal canine supraspinatus tendon: comparison with gross anatomy and histology.

BACKGROUND: This study aimed to compare the ultrasonographic and histological features of the supraspinatus tendon (ST) and its peculiar appearance in contrast with the biceps brachii tendon. METHODS: For this purpose, 19 non-lame dog cadavers were subjected to an ultrasonographic and histologic evaluation of both shoulders after postmortem examination. RESULTS: Close to their insertion on the greater tubercle, all STs displayed a widened portion with a deep central hypoechoic area lacking a fibrillar pattern, when compared with its more proximal aspect and adjacent biceps brachii. Histologically this deep portion corresponded to poorly organised collagen bundles interspersed within a myxoid substance mainly composed of mucopolysaccharides. This central myxoid area with collagen disarray was responsible for the reduced echogenicity on ultrasound. CONCLUSION: The focal widening of the ST insertion and its central mucopolysaccharidic composition could be an anatomical adaptation to marked forces specifically applied to this tendon. However, the ultrasound and histological appearances are very similar to those described in tendinosis, which represents a confounding factor in diagnosing tendonitis at the insertion of the supraspinatus. In the absence of other ultrasonographic criteria of tendinopathy, a hypoechoic central area in the ST near its insertion should be considered normal.

Linear magnetic resonance imaging measurements of the hippocampal formation differ in young versus old dogs.

Age-related hippocampal formation (HF) atrophy has been documented on MRI studies using volumetric analysis and visual rating scales.This retrospective cross-sectional study aimed to compare linear MRI measurements of the HF between young (1-3 years) and old (>10 years) non-brachycephalic dogs, with normal brain anatomy and cerebrospinal fluid (CSF) analysis. Right and left hippocampal formation height (HFH), height of the brain (HB) and mean HFH/HB ratio were measured by two observers on a transverse T2 fluid-attenuated inversion recovery sequence containing rostral colliculi and mesencephalic aqueduct.119 MRI studies were enrolled: 75 young and 44 old dogs. Left and right HFH were greater (p<0.0001) in young, while HB was greater in old dogs (p=0.024). Mean HFH/HB ratio was 15.66 per cent and 18.30 per cent in old and young dogs (p<0.0001). No differences were found comparing measurements between epileptic and non-epileptic dogs.Old dogs have a greater HB; this may represent the different study populations or a statistical phenomenon. Ageing affects HF linear measurements. A reduction of mean HFH/HB ratio between 18.30 per cent and 15.66 per cent should be considered a physiological age-related process of the canine lifespan. The use of mean HFH/HB ratio could be considered for quantifying brain atrophy in elderly dogs.

Presumed Caudal Cerebellar Artery Infarction in Three Cats: Neurological Signs, MRI Findings, and Outcome.

Ischemic cerebrovascular disease (CVD) is a relatively common condition in dogs but infrequent in cats, with acute or peracute onset of non-progressive neurological signs. Cerebellar artery infarction appears to be very uncommon in cats, with only two cases reported affecting the rostral cerebellar artery (RCA). This study aims to report for the first time the neurological signs, magnetic resonance imaging (MRI) findings and outcome in three cats diagnosed with presumed caudal cerebellar artery (CCA) infarction. Unique presentation of vestibular signs associated with CCA in three cats and similarities between dogs and humans are discussed.

Retrobulbar steatitis and meningitis/empyema secondary to right otitis media, right otitis interna and an inflammatory polyp in a cat.

The purpose was to describe a case of retrobulbar steatitis and meningitis in a cat caused by otitis media, otitis interna and an inflammatory polyp in the middle ear. Investigations included ophthalmic and neurological examinations, haematology and biochemistry, magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) analysis and aerobic, anaerobic bacterial and fungal culture of material from the middle ear. A 6-year-old female neutered domestic-short-haired cat presented with right-sided exophthalmos and resistance to retropulsion. Anisocoria, reduced corneal sensation and oculocephalic movements and low Schirmer tear test (STT1) were found. An MRI revealed the right external ear canal and tympanic bulla to be fluid filled with presence of a thickened contrast-enhancing mucosa. Contrast enhancement extended into the calvarium, as marked thickening and contrast enhancement of the pachymeninges, and further rostrally through the right orbital fissure into the orbit. The retrobulbar tissues were swollen, resulting in mild exophthalmos. Enrichment culture of material from the middle ear revealed Klebsiella pneumonia susceptible to marbofloxacin. The cat underwent a total ear canal ablation with removal of the cartilaginous cuff at the external auditory meatus and local debridement and curettage. A polypoid structure was removed from the middle ear. No bulla osteotomy was performed. Horner's syndrome was present immediately following surgery. The cat received a course of systemic dexamethasone (1mg/cat SID/3 weeks) tapered off and marbofloxacin (2mg/kg SID/2 weeks). Follow up at 120 days showed no recurrence of the symptoms. The Horner's syndrome and low STT1 had resolved and returned to normal values respectively. This case highlights the importance of MRI in the investigation of retrobulbar diseases. MRI is a useful tool for the evaluation of the extent of the lesion and the appearance of adjacent structures in which additional potentially life-threatening abnormalities, such as meningitis, can be seen.

Sacrocaudal (sacrococcygeal) intervertebral disc protrusion in 2 cats.

One cat was presented for investigation of urinary retention and constipation and a second cat was presented with decreased appetite, reluctance to jump, reduced level of activity, and constipation. Magnetic resonance imaging revealed dorsal bulging of the hypo-intense intervertebral disc at S3-Cd1 on fast spin echo T2. Dorsal laminectomy was performed and both cats recovered with resolution of neurological signs.

Protrusion discale sacrocaudale (sacrococcygienne) chez 2 chats. Le chat 1 a été présenté en consultation pour exploration d'une rétention urinaire et constipation. Le chat 2 a été présenté en consultation pour baisse d'appétit, réticence à sauter, activité réduite et constipation. L'IRM a mis en évidence une protrusion dorsale du matériel discal hypointense au niveau de S3-Cd1 en fast spin echo T2. Une laminectomie dorsale a été réalisée chez ces deux chats chez qui une complète rémission clinique a été observée.(Traduit par les auteurs).

Magnetic resonance imaging evaluation of olfactory bulb angle and soft palate dimensions in brachycephalic and nonbrachycephalic dogs.

OBJECTIVE To determine from MRI measurements whether soft palate length (SPL) and thickness are correlated in dogs, evaluate the association between the olfactory bulb angle (OBA) and degree of brachycephalia, and determine the correlation between soft palate-epiglottis overlap and OBA in dogs. ANIMALS 50 brachycephalic and 50 nonbrachycephalic client-owned dogs without abnormalities of the head. PROCEDURES Medical records and archived midsagittal T2-weighted MRI images of brachycephalic and nonbrachycephalic dogs' heads were reviewed. Group assignment was based on breed. Data collected included weight, SPL and thickness, OBA, and the distance between the caudal extremity of the soft palate and the basihyoid. Soft palate length and thickness were adjusted on the basis of body weight. RESULTS Brachycephalic dogs had significantly thicker soft palates and lower OBAs, compared with findings for nonbrachycephalic dogs. There was a significant negative correlation (r2 = 0.45) between OBA and soft palate thickness. The correlation between SPL and OBA was less profound (r2 = 0.09). The distance between the caudal extremity of the soft palate and the basihyoid was shorter in brachycephalic dogs than in nonbrachycephalic dogs. The percentage of epiglottis-soft palate overlap significantly decreased with increasing OBA (r2 = 0.31). CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that MRI images can be consistently used to assess anatomic landmarks for measurement of SPL and thickness, OBA, and soft palate-to-epiglottis distance in brachycephalic and nonbrachycephalic dogs. The percentage of epiglottis-soft palate overlap was significantly greater in brachycephalic dogs and was correlated to the degree of brachycephalia.

Orbital paraganglioma in a dog.

A 10-year-old Rottweiler presented with right-sided moderately painful exophthalmia, blindness, absence of dazzle and pupillary light reflexes, a swollen optic nerve head and ventrolateral indentation of the globe. On magnetic resonance imaging, a 3 x 2 x 2 cm mass with a fluid filled center and contrast-enhancing periphery was noted posteriolateral of the globe. Orbital ultrasound was used for a guided fine needle aspirate of the mass. Cytology revealed moderate numbers of polygonal cells with lightly basophilic cytoplasm. Several cells showed nuclear pseudoinclusions. Histopathology following exenteration of the orbit revealed an infiltrative, extradural neoplasm surrounding the optic nerve. Cells were arranged in packets. Neoplastic cells were immunopositive for neuron specific enolase, synaptophysin and chromogranin A and immunonegative for cytokeratin. Findings were consistent with an extra-adrenal paraganglioma (neuroendocrine tumour). Although complete excision could not be confirmed on histopathology, the owners reported no apparent tumour recurrence 25 months after surgery. In conclusion a paraganglioma should be considered as a differential diagnosis of an orbital mass.

Evaluation of T2-weighted versus short-tau inversion recovery sagittal sequences in the identification and localization of canine intervertebral disc extrusion with low-field magnetic resonance imaging.

Sagittal T2-weighted sequences (T2-SAG) are the foundation of spinal protocols when screening for the presence of intervertebral disc extrusion. We often utilize sagittal short-tau inversion recovery sequences (STIR-SAG) as an adjunctive screening series, and experience suggests that this combined approach provides superior detection rates. We hypothesized that STIR-SAG would provide higher sensitivity than T2-SAG in the identification and localization of intervertebral disc extrusion. We further hypothesized that the parallel evaluation of paired T2-SAG and STIR-SAG series would provide a higher sensitivity than could be achieved with either independent sagittal series when viewed in isolation. This retrospective diagnostic accuracy study blindly reviewed T2-SAG and STIR-SAG sequences from dogs (n = 110) with surgically confirmed intervertebral disc extrusion. A consensus between two radiologists found no significant difference in sensitivity between T2-SAG and STIR-SAG during the identification of intervertebral disc extrusion (T2-SAG: 92.7%, STIR-SAG: 94.5%, P = 0.752). Nevertheless, STIR-SAG accurately identified intervertebral disc extrusion in 66.7% of cases where the evaluation of T2-SAG in isolation had provided a false negative diagnosis. Additionally, one radiologist found that the parallel evaluation of paired T2-SAG and STIR-SAG series provided a significantly higher sensitivity than T2-SAG in isolation, during the identification of intervertebral disc extrusion (T2-SAG: 78.2%, paired T2-SAG, and STIR-SAG: 90.9%, P = 0.017). A similar nonsignificant trend was observed when the consensus of both radiologists was taken into consideration (T2-SAG: 92.7%, paired T2-SAG, and STIR-SAG = 97.3%, P = 0.392). We therefore conclude that STIR-SAG is capable of identifying intervertebral disc extrusion that is inconspicuous in T2-SAG, and that STIR-SAG should be considered a useful adjunctive sequence during preliminary sagittal screening for intervertebral disc extrusion in low-field magnetic resonance.

Magnetic resonance imaging features of leukoaraiosis in elderly dogs.

Leukoaraiosis is a descriptive term used to designate bilateral, symmetrical, white matter lesions identified in brains of elderly human patients. These lesions are isointense to normal in magnetic resonance imaging (MRI) T1-weighted pulse sequences, non-contrast enhancing, and hyperintense in T2-weighted and FLAIR pulse sequences. Pathophysiologic mechanisms for leukoaraiosis remain incompletely understood; however, an ischemic origin is currently being favored. Age-related changes, such as brain atrophy, ventricular enlargement, and well-demarcated sulci, have also been previously described in dogs over 9 years of age. Objectives of this retrospective case series study were to describe MRI features of leukoaraiosis and brain atrophy in a group of elderly dogs. The Dick White Referrals MRI database between October 2009 and April 2016 was reviewed. Dogs with bilaterally symmetrical periventricular areas of T2 and FLAIR hyperintensity compatible with leukoaraiosis, and older than 9 years, were included. Fourteen dogs met the inclusion criteria, with a total of 18 MRI studies available for review. Median age for sampled dogs was 13 years. Ten dogs had MRI signs of concurrent brain atrophy; one of them had signs of brain atrophy before leukoaraiotic changes could be identified. In those cases where serial MRIs were available, progressive reduction of interthalamic adhesion thickness was observed. The current study introduces leukoaraiosis as a descriptive term for the MRI sign of bilaterally symmetrical, periventricular T2, and FLAIR hyperintensities in brains of elderly dogs. Future studies are needed to determine pathophysiologic mechanisms for this MRI sign.

A SURVEY OF RADIOLOGISTS AND REFERRING VETERINARIANS REGARDING IMAGING REPORTS.

An imaging report is a vital communication tool between a radiologist and clinician. In a field where in-person communication may not be readily available, it is imperative that the report clearly relays pertinent clinical information in a timely manner. The purpose of this observational study was to describe and compare opinions and expectations of small animal general practitioners, veterinary specialists, and veterinary radiologists regarding the imaging report. Online surveys were distributed, and data were collected from 202 veterinary clinicians and 123 veterinary radiologists. The majority (89%) of clinicians were satisfied with their imaging reports and stated that they read the radiology report as soon as it was available (92%). Just less than half (48%) of clinicians indicated it was standard of care that a board-certified veterinary radiologist read all imaging studies. Radiologists and clinicians agreed that a clinical history (98% and 94%, respectively) and clinical question (82% and 68%, respectively) were needed to generate a good radiology report. Fifty-five percent to 70% of clinicians prefer red bulleted reports, which included incidental findings (96%); while radiologists slightly favored prose reporting (37-46%). Clinicians found it helpful when additional imaging (86%), medical (71%), and surgical recommendations (73%) were made. About one-third of specialists who had been in practice for >11 years thought they were better able to interpret imaging for their own specialty than the radiologist. Clinicians voiced discontentment with reports that were not completed in a timely manner or did not give a prioritized differential list. Further studies are warranted to provide a more in-depth evaluation of veterinary radiology reporting structure and style.

Lumbosacral intraspinal extradural ganglion cyst in a cat.

CASE SUMMARY: A 16-year-old neutered female domestic shorthair cat was referred for chronic history of reluctance to jump, stiffness of the tail and lower back pain. Mild pelvic limb ataxia, reduced perianal reflex and lumbosacral discomfort were present on neurological examination. On magnetic resonance imaging, a well-defined rounded structure of 3 mm in diameter was identified on the right dorsal aspect of the epidural space at L7-S1, causing displacement of the cauda equina. The lesion was hyperintense to spinal cord parenchyma on T2-weighted images and hypointense on T1-weighted images, consistent with a fluid-filled structure. A Lumbosacral dorsal laminectomy was performed. A clear fluid-containing structure was identified between the right L7 nerve root and the cauda equina. Following surgical excision, histopathology confirmed the cystic nature of the lesion and revealed thick disorganised sheaths of fibrocollagenous tissue and flattened mesenchymal cells lining the luminal part of the cyst wall. A diagnosis of intraspinal ganglion cyst was made. The cat recovered uneventfully. Seven months after surgery euthanasia was performed for unrelated reasons; no neurological deficits were present. RELEVANCE AND NOVEL INFORMATION: This is the first reported case of intraspinal ganglion cyst in a cat. Intraspinal extradural cysts should be considered among other differential diagnoses for cats with lumbosacral myelopathy/radiculopathy.

Magnetic resonance imaging characteristics of equine head disorders: 84 cases (2000-2013).

The equine head is an anatomically complex area, therefore advanced tomographic imaging techniques, such as computed tomography or magnetic resonance imaging (MRI), are often required for diagnosis and treatment planning. The purpose of this multicenter retrospective study was to describe MRI characteristics for a large sample of horses with head disorders. Horses imaged over a period of 13 years were recruited. Eighty-four horses met the inclusion criteria, having neurological (n = 65), sinonasal (n = 14), and soft tissue (n = 5) disorders. Magnetic resonance imaging accurately depicted the anatomy and allowed identification of the primary lesion and associated changes. There were good correlations between MRI findings and intraoperative or postmortem results. Magnetic resonance imaging showed the exact localization of the lesions, their size, and relation to surrounding structures. However, in the neurological group, there were 45 horses with no MRI abnormalities, 29 of which had a history of recurrent seizures, related to cryptogenic epilepsy. Magnetic resonance imaging was otherwise a valuable diagnostic tool, and can be used for studying a broad range of head disorders using either low-field or high-field magnets.

Accuracy of a computed tomography bronchial wall thickness to pulmonary artery diameter ratio for assessing bronchial wall thickening in dogs.

Computed tomography is increasingly being used in veterinary medicine to evaluate animals with pulmonary signs such as coughing, tachypnea, and exercise intolerance, however, a quantitative measure of bronchial wall thickening has yet to be validated in veterinary medicine. Canine chronic bronchitis is a disease that is characterized histologically by thickening of the bronchial walls. Thoracic CT images of 16 dogs with chronic bronchitis and 72 dogs presenting for conditions unrelated to cough were evaluated. A ratio comparing the bronchial wall thickness to the adjacent pulmonary artery diameter was obtained in the right and left cranial and caudal lung lobes. There was no significant difference in dogs with chronic bronchitis or unaffected dogs between the left and right hemithorax, patient weight, patient age, image slice thickness, or CT machine used. Dogs with chronic bronchitis were found to have a significantly greater ratio than unaffected dogs (P < 0.001). The ratios in the cranial lung lobes were found to be significantly greater than the caudal lung lobes in both chronic bronchitis and unaffected dogs (P < 0.001). A receiver operating characteristic curve of the ratios in the cranial lung lobes had an area under the curve of 0.912, indicating high accuracy in predicting for bronchial wall thickening. A ratio of ≥ 0.6 in the cranial lung lobes was found to have a sensitivity of 77% and specificity of 100% in predicting for the presence of chronic bronchitis, and we propose using this cut-off as supportive of bronchial wall thickening on CT.

Safety of contrast-enhanced ultrasonography in dogs and cats: 488 cases (2002-2011).

OBJECTIVE: To determine the incidence of adverse events within 24 hours after contrast-enhanced ultrasonography (CEUS) in dogs and cats and compare the risk of death within 24 hours after imaging for animals that underwent ultrasonography with and without injection of a contrast agent. DESIGN: Retrospective case-control study. ANIMALS: 750 animals (411 case dogs, 238 control dogs, 77 case cats, and 24 control cats). PROCEDURES: At 11 institutions, medical records were reviewed of dogs and cats that had CEUS performed (cases) as were medical records of dogs and cats with clinical signs similar to those of case animals that had ultrasonography performed without injection of a contrast agent (controls). Information regarding signalment; preexisting disease; type, dose, and administration route of contrast agent used; immediate (within 1 hour after CEUS) and delayed (> 1 and ≤ 24 hours after CEUS) adverse events; and occurrence and cause of death (when available) was extracted from each medical record. Risk of death within 24 hours after ultrasonography was compared between case and control animals. RESULTS: Of the 411 case dogs, 3 had immediate adverse events (vomiting or syncope) and 1 had a delayed adverse event (vomiting). No adverse events were recorded for case cats. Twenty-three of 357 (6.4%) clinically ill case animals and 14 of 262 (5.3%) clinically ill control animals died within 24 hours after ultrasonography; risk of death did not differ between cases and controls. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that CEUS was safe in dogs and cats.

Ultrasonographic measurement of the pancreas and pancreatic duct in clinically normal dogs.

OBJECTIVE: To obtain ultrasonographic reference values for the thickness of the pancreas and the diameter of the pancreatic duct in clinically normal dogs. ANIMALS: 242 adult dogs with no clinical signs of gastrointestinal tract disease. PROCEDURES: The maximum pancreatic thickness and the diameter of the pancreatic duct were recorded ultrasonographically at the level of the left lobe, body, and right lobe of the pancreas. RESULTS: Mean ± SD pancreatic thickness measurements were as follows: left lobe, 6.5 ± 1.7 mm (n = 214); body, 6.3 ± 1.6 mm (155); and right lobe, 8.1 ± 1.8 mm (239). The mean pancreatic duct diameter was 0.6 ± 0.2 mm (n = 42) in the left lobe and 0.7 ± 0.2 mm (213) in the right lobe. The right pancreatic duct was visible in 213/242 (88.0%) dogs, and the left pancreatic duct was visible in 41/242 (16.9%) dogs. However, the body was visible in only 16/242 (6.6%) dogs. Pancreatic thickness and diameter of the pancreatic duct significantly increased with body weight in all lobes, but age was not correlated with the measurements. CONCLUSIONS AND CLINICAL RELEVANCE: Ultrasonographic reference values for the pancreas and pancreatic duct of dogs were determined. Results of this study indicated that the pancreatic duct was visible, especially in the right lobe of the pancreas. These values may be useful for the assessment of pancreatic abnormalities, such as chronic pancreatitis and exocrine pancreatic insufficiency.

Comparison between clinical, ultrasound, CT, MRI, and pathology findings in dogs presented for suspected thyroid carcinoma.

This study compares clinical, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and pathology findings in 16 prospectively, and seven retrospectively recruited dogs presented for suspected thyroid carcinoma. Of these, 17 were confirmed thyroid carcinoma, while six were initially misdiagnosed. These included four carotid body tumors, one para-esophageal abscess, and one undifferentiated squamous cell carcinoma. Thyroid carcinomas occurred in older dogs without evidence of sex predilection, and were more often unilateral. All were large, heterogeneous, moderately to strongly vascularized, and most commonly contained areas of dystrophic mineralization and/or fluid accumulations. On MRI, thyroid carcinomas appeared hyperintense compared to surrounding musculature in all imaging sequences used, while on CT they had a lower attenuation value than normal thyroid gland tissue. Histologically confirmed tumor capsule disruption with invasion of the surrounding structures was most commonly detected with MRI. Palpation was not an accurate predictor of locally invasive vs. well-encapsulated masses. Computed tomography had the highest specificity (100%) and MRI had the highest sensitivity (93%) in diagnosing thyroid carcinoma, while ultrasound had considerably lower results. We conclude that ultrasound is adequate for use as a screening tool for dogs with suspected thyroid carcinoma, but recommend either CT or MRI for preoperative diagnosis and staging.