Susceptibility weighted imaging (SWI) is a high resolution, fully velocity‐compensated, three‐dimensional gradient echo (GE) MRI technique. In humans, SWI has been reported to be more sensitive than T2*‐weighted GE sequences in the identification of both intracranial hemorrhage and intra‐vascular deoxyhemoglobin. However, published clinical studies comparing SWI to T2*‐weighted GE sequences in dogs are currently lacking. The aim of this retrospective, observational study was to compare SWI and T2*‐weighted GE sequences in a group of dogs with intracranial disease. Medical records were searched for dogs that underwent a brain MRI examination that included T2*‐weighted GE and SWI sequences. The presence and appearance of non‐vascular and vascular signal voids observed on T2*‐weighted GE and SWI were compared. Thirty‐two dogs were included with the following diagnoses: presumed and confirmed intracranial neoplasia (27), cerebrovascular accidents (3), and trauma (2). Hemorrhagic lesions were significantly more conspicuous on SWI than T2*‐weighted GE sequences (P < .0001). Venous structures were well defined in all SWI sequences, and poorly defined in all dogs on T2*‐weighted GE. Susceptibility weighted imaging enabled identification of vascular abnormalities in 30 of 32 (93.8%) dogs, including: neovascularization in 19 of 32 (59.4%) dogs, displacement of perilesional veins in five of 32 (15.6%) dogs, and apparent dilation of perilesional veins in 10 of 32 (31.3%) dogs. Presence of neovascularization was significantly associated with T1‐weighted post‐contrast enhancement (P = .0184). Hemorrhagic lesions and venous structures were more conspicuous on SWI compared to T2*‐weighted GE sequences. Authors recommend adding SWI to standard brain protocols in dogs for detecting hemorrhage and identifying venous abnormalities for lesion characterization.

Carcinomatosis and sarcomatosis describe the widespread dissemination of metastatic neoplastic cells throughout the body. Studies describing their clinical and imaging features in veterinary patients are limited. The objective of this retrospective, multicenter, cross-sectional study is to describe the clinical, ultrasonographic, and CT features of pleural and peritoneal carcinomatosis and sarcomatosis in dogs and cats to aid detection and differentiation of these lesions. Medical records and CT and ultrasonographic images were reviewed. Although a large degree of overlap was observed between the imaging features and clinical signs of canine and feline carcinomatosis and sarcomatosis, some distinguishing features were observed. Dogs were significantly more likely to present with abdominal pain compared to cats (P = .022), whereas cats more commonly presented with inappetence (P = .019). Dogs with sarcomatosis had a significantly heavier bodyweight than dogs with carcinomatosis (P = .005), largely due to a higher prevalence of splenic hemangiosarcoma in this patient cohort. Peritoneal effusion was more frequently observed in dogs with carcinomatosis compared to dogs with sarcomatosis (P = .021). Imaging and clinical features observed in this study may help to distinguish sarcomatosis and carcinomatosis lesions. Due to the large degree of overlap observed, cytological or histopathological analysis is recommended for definitive diagnosis.

Background Abdominal ultrasound is frequently used to detect non‐perforated gastroduodenal ulcers in dogs. Studies assessing the diagnostic utility of abdominal ultrasound for the detection of non‐perforated gastroduodenal ulcers have yielded mixed results. No studies to date have investigated the effects of patient bodyweight, breed, sex, age, ulcer aetiology (neoplastic or inflammatory) or location on the diagnostic accuracy of abdominal ultrasound. Methods Retrospective, multicentre study to evaluate the diagnostic utility of abdominal ultrasonography for the diagnosis of non‐perforated gastroduodenal ulceration in dogs. Results Sixty‐one dogs met the inclusion criteria. Ulcers were detected during ultrasound examination in 18 of 61 dogs, yielding a sensitivity of 29.5% (95% confidence interval 18.8%–42.7%). Ulcers in the pyloric region were detected more frequently than those in the duodenum; however, location was not significantly associated with the ability of ultrasound to detect lesions (p = 0.41). No associations were identified between the ability of ultrasound to detect an ulcer and patient bodyweight (p = 0.45), breed (p = 0.98), sex (p = 0.90), age (p = 0.94), and neoplastic versus inflammatory nature of ulcerative lesions (p = 0.93). Conclusion The diagnostic utility of ultrasound as the sole modality for the detection of non‐perforated gastroduodenal mucosal ulceration is poor. The authors therefore recommend the use of additional modalities when ulcerative lesions are suspected.

Magnetic resonance imaging (MRI) signal changes associated with ischemic stroke are typically described as T2w and FLAIR hyperintense, and T1w isointense lesions. Intralesional T1w hyperintensity is generally attributed to either a hemorrhagic stroke, or an ischemic stroke with hemorrhagic transition, and has an associated signal void on gradient echo (GE) sequences. Cases of ischemic stroke with T1w hyperintense signal in absence of associated signal void on GE sequences have been sporadically demonstrated in human stroke patients, as well as in dogs with experimentally induced ischemia of the middle cerebral artery. This multicenter retrospective descriptive study investigates the presence of T1w hyperintensity in canine stroke without associated signal void on GE sequences. High field (1.5 Tesla) MRI studies of 12 dogs with clinical presentation, MRI features, and cerebrospinal fluid results suggestive of non-hemorrhagic stroke were assessed. The time between the observed onset of clinical signs and MRI assessment was recorded. All 12 patients had an intralesional T1w hyperintense signal compared to gray and white matter, and absence of signal void on T2*w GE or SWI sequences. Intralesional T1w hyperintensities were either homogenously distributed throughout the entire lesion (6/12) or had a rim-like peripheral distribution (6/12). The mean time between the recorded onset of clinical signs and MRI assessment was 3 days; however, the age range of lesions with T1w hyperintense signal observed was 1–21days, suggesting that such signal intensities can be observed in acute, subacute, or chronic stages of ischemic stroke. Follow-up was recorded for 7/12 cases, all of which showed evidence of neurological improvement while in hospital, and survived to discharge. Correlation of the age and MRI appearance of lesions in this study with similar lesions observed in human and experimental studies suggests that these T1w hyperintensities are likely caused by partial tissue infarction or selective neuronal necrosis, providing an alternative differential for these T1w hyperintensities observed.

Pseudoankylosis of the temporomandibular joint is infrequent in veterinary practice and mostly seen secondary to trauma. This case report describes the surgical treatment of a 1-year old, male, entire lurcher that presented with progressive lateral deviation of the muzzle to the left and decreased vertical mandibular range of motion of 6-month duration. There was no history of trauma, no pain on palpation and complete loss of temporomandibular joint movement, even under sedation. Computed tomography investigation showed a left-sided temporomandibular pseudoankylosis with osseous fusion between the zygomatic arch and mandible. Surgical excision of the ankylosed bone was performed and achieved an initial 5 cm interincisal gap. The surgical site healed, with no complications reported. Re-examination at 4 weeks revealed good vertical mandibular range of motion with interincisal gap of approximately 5 cm. At 9 months post-operatively, the dog had maintained good vertical mandibular range of motion and was able to eat normally, pant and hold large toys.

A 7-year-old female neutered Tibetan Terrier presented with a 2-week history of bilateral mandibular swelling, lethargy, reduced appetite, pyrexia and right sided exophthalmos. Computed tomography (CT) identified severe bilateral enlargement and heterogenicity of the mandibular salivary glands, which contained multiple cavitary lesions. Cytology of both mandibular salivary glands confirmed necrotising sialometaplasia. The treatment with phenobarbitone, omeprazole and paracetamol was initiated. The patient made a dramatic improvement upon 3-week follow up, with marked reduction in size of the mandibular salivary glands and resolution of clinical signs. To the authors' knowledge, this is the first reported case describing the CT imaging features of necrotising sialometaplasia. K E Y WO R D S cavitations, necrotising sialometaplasia, phenobarbitone, salivary gland disease BACKGROUNDThis case describes previously unreported computed tomography (CT) features of canine necrotising sialometaplasia, a distinct clinical entity that to date has only been described in histopathological or clinical reports in veterinary patients. [1][2][3][4][5][6][7] This condition is characterised by painful lobular necrosis, fibrosis and squamous metaplasia of the affected salivary glands. 2,8,9 Both spontaneous resolution and response to phenobarbitone treatment have been reported in veterinary patients. 10,11 This case describes the imaging features of a condition that should be a differential diagnosis for aggressive salivary disease.