Diagnostic Imaging of Diseases Affecting the Guttural Pouch.

The most common diseases of the guttural pouch are empyema, tympany, mycosis and temporohyoid osteoarthropathy. The challenge in diagnosis of guttural pouch diseases lies in the complex anatomy of the guttural pouch and adjacent associated structures. Diagnostic imaging is a good complement to endoscopy for the diagnosis of some guttural pouch diseases, especially to make a full assessment of the lesions involving the pouch and surrounding structures. This review article describes the value of each diagnostic imaging technique in the diagnosis of guttural pouch disease and the corresponding imaging findings. Radiography is generally used as the first line to complement endoscopic findings, and can give useful additional information although it is limited by superimposition. Ultrasonographic examination of the guttural pouch is of limited value due to the presence of gas in the guttural pouch but can eventually be used to detect fluid within the pouch or can help to evaluate the soft tissues located lateral and ventral to the guttural pouch. Cross-sectional imaging, especially CT, is increasingly available and appears to be the best technique to fully assess the surrounding soft tissues and to precisely identify lesions of the temporohyoid apparatus, temporal bone and skull base that are associated with guttural pouch disease.

Ultrasonographic findings of feline aortic thromboembolism.

OBJECTIVES: The aim of the study was to describe the ultrasonographic characteristics of feline aortic thromboembolism (ATE) and determine potential associations between ultrasonographic findings and prognosis. METHODS: Data were retrospectively collected from the medical records (2013-2021) of cats that were diagnosed ultrasonographically with ATE based on the presence of a thromboembolus (TE) in the distal aorta beginning after the departure of the renal arteries. RESULTS: Twenty-nine cats were included in this study. The most frequent location for an ATE was at the aortic trifurcation. The median length of TEs was 9 mm (range 3.5-42.9). TEs appeared homogeneous and isoechoic to surrounding tissues in all cases. No correlation was found between the appearance of the TE and the duration of clinical signs. The obstruction of blood flow in the distal aorta at the aortic trifurcation was complete in 66% of cases and incomplete in 34% of cases. The survival rate was significantly lower when the obstruction was complete (11%, 95% confidence interval [CI] 2-34) compared with incomplete (70%, 95% CI 35-92). The arterial wall characteristics were as follows: smooth and thin (62%), and hyperechoic (38%). CONCLUSIONS AND RELEVANCE: Increased vascular obstruction of TEs was associated with a lower survival rate.

CT is a feasible imaging technique for detecting lesions in horses with elbow lameness: A study of 139 elbows in 99 horses.

Computed tomography (CT)is increasingly available in veterinary referral practices; however, published studies describing CT lesions of the equine elbow are currently lacking. In this single-center, retrospective, observational study, horses undergoing elbow CT at Equitom between July 2015 and October 2018 were reviewed. Subchondral bone sclerosis; resorption of the radius, ulna, and humerus; osteophyte; and enthesophyte lesions were graded. One hundred thirty-nine elbows of 99 horses (16 with elbow pain and 123 control elbows) were included (median age, 9 years). Osseous cyst-like lesions (n = 13), only seen in the proximomedial radius and medial humerus, were the most common cause of lameness in horses with elbow pain (n = 16), with significantly higher grades of bone resorption (including osseous cyst-like lesions) in this group. One elbow had an avulsion fracture of the lateral epicondyle, two others showed signs of osteoarthritis. Significantly higher grades of sclerosis in the proximomedial radius were seen in horses with elbow pain; however, mild to moderate subchondral bone sclerosis was seen in all horses at the medial aspect of the joint. Osteochondral fragmentation lesions of the weight-bearing surface of the medial radius (2/16 vs 1/123; P = .0025) and intra-articular gas (4/16 vs 2/123; P < .0001) were significantly more common in horses with elbow pain compared to control horses. Mild linear resorptive subchondral bone lesions were often not clinically relevant (32/123 vs 5/16 in medial humerus; 19/123 vs 2/16 in medial radius). In conclusion, elbow CT is a feasible method for detecting clinically relevant lesions in adult Warmblood horses with elbow pain.

Comparison of imaging techniques to detect migrating foreign bodies. Relevance of preoperative and intraoperative ultrasonography for diagnosis and surgical removal.

OBJECTIVE: To report the relative sensitivity of different diagnostic imaging (DI) techniques to detect migrating foreign bodies (FB) in subcutaneous and underlying soft tissue structures of dogs and evaluate the value of intraoperative ultrasonography (intraop-US). STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Forty-one dogs. METHODS: Medical records (2007-2019) of dogs that underwent surgery for a chronic abscess or draining tract were included when preoperative US (preop-US), computed tomography (preop-CT), or preop-MRI, and at least 6 months of follow-up information were available. Collected data included the DI techniques used, DI findings, and surgical findings. The relative sensitivity of each preoperative DI (preop-DI) technique was calculated. Dogs were divided into two groups, dogs that underwent only a preop-DI examination (group A) and dogs that underwent an additional intraop-US (group B). The success rates for FB surgical removal were compared between groups. RESULTS: The relative sensitivity of preop-US and preop-CT/MRI was 88% (95% CI, 70%-95.8%) and 57.1% (95% CI, 32.6%-78.6%), respectively. The success rate for FB removal was higher in group B (89.5%) than in group A (59.1%; P = .038). Clinical resolution occurred in 90.2% of dogs for a median duration of follow-up of 4.2 years (6 months to 9.3 years). CONCLUSION: Preoperative US seems more suitable than preop-CT/MRI for detection of migrating FB in subcutaneous and underlying soft tissue structures. The use of intraop-US increases the success rate for FB surgical removal. CLINICAL SIGNIFICANCE: Intraoperative US should be used in combination with preop-US to increase the likelihood of migrating FB surgical removal in dogs.

Prevalence and diagnostic value of the ultrasonographic honeycomb appearance of the spleen in cats.

OBJECTIVES: The aim of this study was to report the prevalence of a honeycomb appearance of the spleen in a population of referral cats presented for ultrasound examination, and to determine the diagnostic value of this finding vs the definitive diagnosis, the splenic cytological and haematological results. METHODS: Data were obtained from the medical records (2016-2018) of cats that had an ultrasonographic honeycomb appearance of the spleen, a splenic cytological diagnosis and a complete blood count. RESULTS: Twenty-five cats were included. Prevalence of the honeycomb pattern was 6.8%. None of the spleen was considered normal on cytology and four types of lesions were found: lymphoid hyperplasia (64%), neoplasia (16%), extramedullary haematopoiesis (12%) and splenitis (8%). A honeycomb pattern was successfully identified with a linear high-frequency probe in all cats, but only in 36% of cases with the micro-convex probe. Follow-up information was available for four cats, in which the honeycomb appearance persisted up to 105 days after the first examination; there was persistence of the honeycomb pattern in all cases. Cats with a splenic cytological diagnosis of extramedullary haematopoiesis had the lowest haemoglobin plasma concentration (P = 0.011). CONCLUSIONS AND RELEVANCE: Honeycomb appearance of the spleen is uncommon in cats and, in our study, was systematically associated with cytological alterations; most of the time it was benign (84%). The use of a high-frequency linear probe improves its detection rate. No epidemiological, ultrasonographic or clinical criteria allow differentiation between the different types of infiltration and fine-needle aspiration is therefore recommended.

Use of contrast-enhanced ultrasonography for the detection of a feline insulinoma.

CASE SUMMARY: A 14-year-old cat was presented with a 2-week history of ataxia, seizure-like episodes, vomiting and weight loss. Serum biochemistry revealed severe hypoglycaemia, associated with low serum fructosamine and high insulin concentrations. On abdominal ultrasound, a focal hypoechoic well-defined mass in the left limb of the pancreas was identified and the presence of an additional smaller nodule was suspected. Contrast-enhanced ultrasonography (CEUS) confirmed the presence of both lesions and revealed a third, even smaller nodule. Partial pancreatectomy was performed. Histopathology and immunohistochemistry confirmed the presence of a multifocal insulinoma. Six months later, the cat presented with tenesmus and obstipation. A colorectal adenocarcinoma was diagnosed with histopathology after partial excision of a colorectal mass. The cat was euthanased a month later owing to recurrent episodes of severe obstipation. RELEVANCE AND NOVEL INFORMATION: This is the first clinical description of the use of CEUS in the diagnosis of feline insulinoma. Furthermore, the available scientific literature on feline insulinoma was reviewed.

Bone marrow lesions of the distal condyles of the third metacarpal bone are common and not always related to lameness in sports and pleasure horses.

The metacarpophalangeal joint is a common site of pain in horses. Little information is available about bone marrow lesions in the distal condyles of the third metacarpal bone in sports and pleasure horses. Aims of this prospective, retrospective, observational study were to evaluate the prevalence of bone marrow lesions in the distal condyles of the third metacarpal bone, to describe their anatomic distribution and to correlate lesions with the presence of lameness and the level and type of activity. All sports and pleasure horses undergoing standing low-field MRI of the front fetlock region between 2009 and 2016 were included and divided into three lameness groups according to the results of diagnostic analgesia. Bone marrow lesions were analyzed and graded by one reader. Grades were compared between anatomical locations and between lameness groups. A total of 166 horses were sampled. The prevalence of bone marrow lesions was 76.5% (127/166). The dorsal aspects of the medial condyle (31%, 39/127) and of the sagittal ridge (28%, 36/127) were the most commonly affected locations. There was no significant difference between both forelimbs (lame limb and non-lame limb) of the same horse. Lesion severity was neither significantly associated with the lameness group nor with the type or level of activity. The prevalence of bone marrow lesions in the distal condyles of the third metacarpal bone is high in this population and the clinical significance is not always clear. Further studies are required to elucidate the clinical significance of this finding in sports and pleasure horses.