ABSTRACTA 7‐year‐old female neutered French Bulldog presented with left thoracic limb paresis. Twelve months earlier, the dog had been treated with 3D conformal radiotherapy for a right piriform lobe mass (suspected glioma), which had a strong partial response following treatment. Magnetic resonance imaging (MRI) revealed an intramedullary lesion of the cervical spinal cord, suspected to be drop metastasis. This lesion was treated with intensity‐modulated radiotherapy (IMRT) (10 fractions of 3.6 Gy, total 36 Gy), with a response documented on MRI, alongside resolution of clinical signs. The dog died of unrelated causes 647 days following IMRT, and the diagnosis was confirmed at post‐mortem examination.

ABSTRACTCollet–Sicard syndrome (CSS) is a rare neurological condition characterized by concomitant dysfunction of cranial nerves (CNs) IX–XII, resulting in variable combinations of dysphagia, dysphonia, and tongue paresis or paralysis. This retrospective case series describes three dogs diagnosed with CSS secondary to a suspected brainstem meningioma that were treated with definitive radiotherapy (RT). All dogs received volumetric‐modulated arc therapy with a total dose of 50 Gy (20 × 2.5 Gy fractions). Supportive medical management was maintained during and after RT. Clinical signs varied among dogs depending on the severity of CN involvement, and all showed clinical improvement after RT. Two dogs who achieved stable disease post‐RT were euthanized due to progressive clinical signs at 344 and 421 days post‐RT, while one dog who achieved partial response post‐RT remains alive with sustained clinical improvement at 652 days. No early or late adverse effects were recorded. This case series describes the use of RT, follow‐up advanced imaging, and medical management for the treatment of CSS in three dogs with suspected neoplastic causes.

ABSTRACTComputed tomography (CT) of postoperative orthopedic cases can yield valuable clinical information, especially when radiographic findings are equivocal. Image quality can be adversely affected by the presence of metallic implants. Several studies evaluating metal artifacts on CT have been published in humans, but studies involving veterinary patients are limited. This study aimed to assess attenuation value changes caused by metal artifacts on adjacent anatomical structures. This prospective cadaveric study included 20 Greyhound cadaver forelimbs. The limbs underwent CT before and after application of a 316L stainless steel plate and screws along the cranial surface of the radius. Attenuation values of the radial cortex, medulla, and caudal soft tissues were compared before and after implant placement. Five anatomical sites along the antebrachium were selected for comparison: (1) at the level of a non‐filled plate hole, (2) along the plate between 2 screws, (3) at the edge of the plate, and (4) 1 and (5) 3 cm proximal to the plate, respectively. The attenuation values between pre‐ and post‐implant images were significantly different in the radial medulla, cranial, and caudal cortices at Sites 2 and 3, and in the cranial radial cortex at Site 1. No significant differences were found in the antebrachial caudal soft tissues at any site, nor at any region at Sites 4 and 5. The presence of stainless steel implants significantly affects the attenuation values of adjacent cortical and medullary bone, which may lead to image interpretation errors.

ABSTRACTThe presence of adhesion created by an adrenal tumor (AT) with adjacent structures is important information for surgical planning. We aimed to establish the accuracy of computed tomography (CT) in predicting adrenal tumor adhesion (ATA) with adjacent organs and vessels. This prospective multicenter study enrolled 30 dogs and 2 cats with AT, pre‐ and post‐contrast CT, and adrenalectomy. Images were reviewed by five blinded radiologists using consensus‐based CT criteria for adhesions (five criteria for vessels and eight for organs). During surgery, ATA was observed in 27/32 patients (84.4%). A single criterion alone could not predict the presence of adhesion. Using a probabilistic classification tree, combinations of two or more criteria with other variables (side, image quality, and tumor rupture) showed good accuracy in predicting ATA for some organs and vessels. For vessels, the combination of some criteria could predict the presence of adhesion: for example, for the caudal vena cava, a combination of criteria 1 + 3 + 4 + 5 in a right AT had an accuracy of 86.2%; for the renal vein, the combined 1 + 2+ 3 + 4 + 5 criteria had an accuracy of 84.8% and 93.8% in a CT study of excellent quality. For organs, a combination of specific criteria could predict adhesion: for the kidney, the combination 1 + 2+ 3 + 4 + 5 had an accuracy of 90%. Radiologist's agreement for detecting ATA was excellent (>80%). A combination of repeatable CT criteria could provide probabilistic information for the presence of ATA with adjacent organs and vessels.

ABSTRACTOptimal radiation protocols for canine nasal carcinoma are not established. Co‐morbidities, access, and owner compliance can influence scheduling. Between 2015 and 2022, two radiotherapy protocols were used in the palliative treatment of canine nasal carcinoma at a single institution. Group A comprised 17 cases receiving 40 Gy in ten 4 Gy fractions delivered Monday, Wednesday, and Friday. Epistaxis was present in 11/17 (65%) cases. Median survival time (MST) was 298 days (95% CI: 163.54–432.45); progression‐free survival was 173 days (95% CI: 117.87–228.12). Group B comprised 24 cases receiving 36 Gy in six 6 Gy fractions delivered Monday and Friday. Epistaxis was present in 20/24 (83%) cases. MST was 375 days (95% CI: 240.73–509.27); progression‐free survival was 243 days (95% CI: 138.42–347.58). Dogs with Adams Stage 1 disease had the longest median overall (593 days) and progression‐free survival (609 days). Four cases each received additional radiation treatment and/or toceranib at relapse. Palliative radiation therapy achieved control of clinical signs in the majority of cases, with an overall response rate of 100% (Group A) and 96% (Group B). In a multivariate Cox regression model with backwards elimination, when cases were stratified for tumor stage, neither the presence of epistaxis nor treatment (6 vs. 10 fractions) was independently associated with significant improvements in survival. Epistaxis at presentation did not appear to influence survival. These results indicate that palliative radiation therapy is highly effective in controlling clinical signs associated with nasal carcinoma. Increasing fractionation may have a limited effect on survival outcome or toxicity in the palliative setting.

ABSTRACTA 3‐year‐old male neutered Labrador Retriever was originally presented to his primary care veterinarian for a 3–4‐week history of hyporexia, a 1‐week history of anorexia, and vomiting. There was moderate gastrointestinal (GI) distention with heterogeneous soft tissue luminal material within the small intestine in screening abdominal radiographs. Referral and computed tomography were performed, identifying a severe generalized dilation of the GI tract but no obstructive lesion. Severe functional intestinal ileus without obstruction was diagnosed. The patient underwent laparotomy with full‐thickness intestinal surgical biopsies due to presumptive infiltrative enteropathy, yielding a diagnosis of intestinal leiomyositis.

ABSTRACTA 4‐year‐old castrated male Pomeranian dog with a 2‐year history of necrotizing encephalitis (NE) presented for acute neurological deterioration without trauma. Magnetic resonance imaging (MRI) revealed a broad crescent‐shaped lesion with mixed signal intensities on T1‐ and T2‐weighted images, hypointense areas on T2* images, contrast enhancement in the outer membrane, and a mass‐like lesion with fluid–fluid layers. The lesion was diagnosed as a chronic subdural hematoma secondary to spontaneous hemorrhage in a dog with NE. A direct causal relationship remains uncertain; however, NE could have contributed to the increased vulnerability of bridging veins. Serial MRI evaluations revealed progression of the lesion. This is the first report describing the MRI features of chronic subdural hematoma in a dog with NE.

ABSTRACTMedial coronoid process disease (MCPD) is the most frequently observed cause of elbow dysplasia, resulting in lameness in young, fast‐growing large‐breed dogs, including Labrador Retrievers (LRs). Computed tomography (CT) is the diagnostic imaging modality of choice for evaluating the medial coronoid process (MCP), as it is noninvasive and eliminates superimposition of the process by the radial head. This retrospective descriptive study aimed to describe the shape of the normal MCP on CT, to assess its variability within the LR breed, and to determine the normal Hounsfield units (HUs) of the MCP, medial radial head (MRH), and lateral radial head (LRH). Normal elbow CT studies of 51 South African guide dog LRs were reviewed. Using a repeatable imaging alignment technique, three principal MCP shapes were identified: ovoid, triangular, and softly pointed and were found to be dependent on the level of assessment. Males had significantly lower mean MCP HU compared to females. The mean HU of the MRH was consistently higher than the LRH and was also greater in attenuation on subjective assessment. Measuring MCP and radial head HU too proximally was suboptimal, as volume averaging was frequently encountered. The results of this study showed that although different alignment techniques may result in HU variations, they will not affect the HU to such an extent that the MCP would be misclassified as abnormal.

ABSTRACTA 1‐month‐old Arabian filly presented for central neurologic signs that developed shortly after birth. Hyperammonemia and elevated bile acids were identified, prompting abdominal computed tomography angiography (CTA) evaluation on suspicion of congenital portosystemic shunting (PSS). CTA revealed an anomalous vessel connecting the intrahepatic central divisional portal branch and caudal vena cava, with microhepatica and bilateral renomegaly. Necropsy confirmed a single, congenital, and intrahepatic central divisional portocaval shunt. Imaging literature addressing PSS in foals is sparse, with the current case representing the first instance in which CTA alone was fully diagnostic of an intrahepatic shunt in a foal.

ABSTRACTUltrasonography in veterinary medicine serves a vital role in the diagnosis and management of various medical conditions by allowing noninvasive visualization of internal structures. Veterinary students face many challenges in gaining hands‐on experience with ultrasound equipment and developing competencies in ultrasonography. This is largely due to the limited access and ethical dilemmas of live animal models and the high cost of commercial phantoms. To solve these issues, the niche of cost‐effective amateur models has exponentially increased. However, while these at‐home models solve the financial issues associated with commercial phantoms, they still lack the realism and fidelity necessary to simulate the real‐time feedback needed to gain the spatial awareness of this dynamic imaging modality. To foster successful day‐one‐ready veterinary students, The Ohio State University College of Veterinary Medicine acknowledged that a better solution should be possible. A prospective anatomic study was performed to recognize the imaging anatomy and usability of a new model termed the Danny Phantom. This model was developed by testing various amateur phantom materials from both the literature and self‐discovered. These materials were analyzed and deemed satisfactory versus unsatisfactory based on fulfillment of predetermined criteria of an ideal phantom model. It was determined that real fixed organs can be encased in traditional bovine gelatin to produce an ultrasound phantom with recognizable parenchyma. Other additives can be included to give the phantom an imitated peritoneal space and prevent spoilage of the gelatin for an extended period of time.