64-Slice ECG-gated computed tomographic angiography for assessment of coronary arteries in brachycephalic dogs with pulmonary stenosis.

BACKGROUND: Brachycephalic dogs with pulmonary stenosis are known to have a higher incidence of concurrent coronary artery abnormalities than non-brachycephalic breeds, which increases risk when performing balloon valvuloplasty. The use of ECG-gated CT angiography has been reported for the evaluation of coronary arteries in normal dogs and dogs with pulmonary stenosis. The purpose of this study was to report findings of coronary artery origination and morphology of main branches using ECG-gated CT angiography in brachycephalic dogs with pulmonary stenosis. METHODS: An ECG-gated CT angiographic protocol was used to image coronary artery anatomy in nine brachycephalic dogs with pulmonary stenosis. Images were assessed for quality as well as coronary artery morphology by one veterinary radiologist, one veterinary cardiologist and one veterinary radiology resident. RESULTS: All nine dogs had good to excellent image quality. Coronary artery anomalies were identified in three of nine dogs: one R2A anomaly, one L2A anomaly and one L2C anomaly. Two dogs were assessed to be poor balloon valvuloplasty candidates based on CT angiographic images. LIMITATION: Coronary artery morphology was not confirmed via postmortem examination in all patients. CONCLUSION: ECG-gated CT angiography is a minimally invasive imaging modality capable of diagnosing various coronary artery anomalies in brachycephalic dogs with pulmonary stenosis and aiding in the determination of patient candidacy for balloon valvuloplasty.

Development of three-dimensional cardiac models from computed tomography angiography.

Three-dimensional (3D) modeling and printing is an emerging technology in veterinary cardiovascular medicine allowing the fabrication of anatomically correct patient-specific models. These patient-specific models can be used for a wide range of purposes including medical teaching, assessment of cardiac function and movement of valve leaflets, design and assessment of devices created for interventional procedures, and pre-surgical planning [1-3]. Additionally, these 3D models can facilitate communication between the clinical team and the patient's owner. The process of creating 3D models starts with acquiring volumetric imaging data sets of the area of interest. Three-dimensional modeling and printing are reliable when high-quality volumetric imaging data are used to create these models. Currently, only ungated- and electrocardiogram (ECG)-gated computed tomography (CT), cardiac magnetic resonance imaging (CMRI), and 3D echocardiography provide the volumetric data sets needed to create these 3D models. These imaging data sets are imported into a software or open-source freeware platform and then segmented to create a virtual 3D model. This virtual 3D model can be further refined using computer-aided design (CAD) software and then be printed to create a physical 3D model. Cardiovascular 3D modeling and printing is a new medical tool which allows us to expand the way we plan interventional procedures, practice interventional skills, communicate with the medical team and owner, and teach future veterinarians.

Comparison of two-dimensional imaging to three-dimensional modeling of intrahepatic portosystemic shunts using computed tomography angiography.

Computed tomography angiography (CTA) is used for the diagnosis of intrahepatic portosystemic shunts (IHPSS). When planning for transcatheter intervention, caudal vena cava (CVC) measurements are typically obtained from two-dimensional (2D) imaging to aid in stent selection. We hypothesized that clinically applicable three-dimensional (3D) IHPSS models can be generated, and CVC measurements will not differ between 2D images and 3D models. Computed tomography angiography datasets from client-owned dogs with IHPSS at the University of Georgia Veterinary Teaching Hospital from 2016 to 2022 were analyzed. Materialise Mimics 25.0 and 3-matic 17.0 were used for 3D modeling. Caudal vena cava diameters were measured in 2D dorsal and transverse planes 20 mm cranial and caudal from the shunt ostium and were compared with CVC diameters from 3D models. Length was measured in the 2D dorsal plane between midpoints of each diameter and compared to the 3D model length. Data are presented as mean (SD), and intraclass correlation coefficients were performed. Three-dimensional models were generated for 32 IHPSS (15 right-, 12 left-, and five central-divisional). Two-dimensional dorsal and transverse area-associated diameter measurements were 16.7 mm (5.6) and 15.5 mm (4.2) cranial; 14.9 mm (4.2) and 14.3 mm (3.7) caudal. Three-dimensional area-associated diameter measurements were 15.3 mm (4.4) cranial and 14.0 mm (3.6) caudal. The 2D length was 61.5 mm (7.1) compared with 3D 59.9 mm (7.2). Intraclass correlation coefficients comparing 2D and 3D diameters were all >0.80, indicating very good agreement, with good agreement (>0.60) for length. Clinically applicable 3D IHPSS models can be generated using engineering software. Measurements from 3D models are consistent with 2D planar imaging. Both 2D CTA and 3D virtual models can be utilized for preprocedural planning, depending on clinician preference.

Comparison of bone subtraction CT angiography with standard CT angiography for evaluating circle of Willis in normal dogs.

BACKGROUND: Bone subtraction computed tomography angiography (BSCTA) is a useful alternative technique for improving visualization of vessels surrounded by skull bone. However, no studies have compared computed tomography angiography (CTA) and BSCTA for improving the visibility of canine cerebral blood vessels. OBJECTIVES: To evaluate the potential benefit of BSCTA for better delineation of brain arteries of the circle of Willis (CoW) in dogs by comparing BSCTA with non-subtraction computed tomography angiography (NSCTA). METHODS: Brain CTA was performed for nine healthy beagle dogs using a bolus tracking method with saline flushing. A total dose of 600 mgI/kg of contrast agent with an iodine content of 370 mgI/mL was injected at a rate of 4 ml/s. Bone removal was achieved automatically by subtracting non-enhanced computed tomography (CT) data from contrast CT data. Five main intracranial arteries of the CoW were analyzed and graded on a scale of five for qualitative evaluation. RESULTS: Scores of basilar artery, middle cerebral artery, and rostral cerebral artery in the BSCTA group were significantly higher than those in the NSCTA group (p = 0.001, p = 0.020, and p < 0.0001, respectively). Scores of rostral cerebellar artery (RcA) and caudal cerebral artery (CCA) did not differ significantly between the two groups. However, scores of RcA and CCA in the BSCTA group were higher than those in the NSCTA group. CONCLUSIONS: BSCTA improved visualization of intracranial arteries of the CoW with close contact to bone. Thus, it should be recommended as a routine scan method in dogs suspected of having brain vessel disease.

Percutaneous shunt vessel embolisation with Amplatzer vascular plugs II and IV in the treatment of dogs with splenophrenic shunts: four cases (2019-2022).

OBJECTIVES: To describe the treatment of four dogs with splenophrenic shunts using percutaneous shunting vessel embolisation with Amplatzer vascular plugs II and IV and provide information on their clinical outcomes. MATERIALS AND METHODS: Dogs with splenophrenic shunts treated at a veterinary hospital from January 2019 to December 2022 were identified through a medical record search. RESULTS: Six dogs with splenophrenic shunts were identified. Two dogs were excluded because they were treated with laparoscopic surgery. Four underwent percutaneous shunting vessel embolization with Amplatzer vascular plugs and were included in the case series. A sheath was placed in the left external jugular vein and a balloon catheter was advanced to the shunting vessel under fluoroscopy. Portal vein pressure was confirmed to be within an acceptable range during temporary balloon occlusion. Based on preoperative CT angiography and intraoperative contrast examination, Amplatzer vascular plugs II were selected for two dogs and IV were selected for two dogs. Under fluoroscopy, the plug was deployed into the shunting vessel, and angiography confirmed occlusion. In all cases, the increase in portal pressure after temporary occlusion was within the acceptable range, and complete occlusion of blood flow was possible with a single plug. There were no major procedure-related complications. No dogs developed post-ligation seizures or signs of portal hypertension. In addition, improvements in ammonia values were observed in all cases. CLINICAL SIGNIFICANCE: Percutaneous splenophrenic shunt embolisation using Amplatzer vascular plugs II and IV is technically feasible in dogs, and assessed by intra-procedure angiography, a single plug completely obstructed blood flow in all dogs. Based on the literature search, this is the first report describing Amplatzer vascular plugs for the treatment of splenophrenic shunts.

Optimizing contrast protocol for bone-subtraction CT angiography of intracranial arteries in normal dogs using 160-slice CT.

BACKGROUND: Bone-subtraction computed tomography angiography (CTA) (BSCTA) is a new technique designed to overcome the limitation of three-dimensional CTA, where the vessels surrounded by bone and calcification can be obscured. An optimal contrast CT protocol for intracranial artery visualization with BSCTA has yet to be established in dogs. OBJECTIVES: The purpose of this study was to determine the optimal contrast protocol of CTA for visualizing intracranial artery using an automatic bone-subtraction technique in dogs. METHODS: Brain CTA was performed four times for each of nine healthy beagle dogs to cover all the contrast protocols: two different contrast iodine concentrations (300 and 370 mgI/mL) and two different contrast media injection rates (2 and 4 mL/s). Bone removal post-processing was performed automatically by subtracting the non-enhanced CT data from the contrast CT data using a dedicated workstation. The bone-subtracted intracranial vessels were analysed for quantitative and qualitative evaluation. RESULTS: Quantitative evaluation showed significantly higher CT attenuation values for the group with a 370 mgI/mL iodine content at a rate of 4 mL/s than the two groups with a 300 mgI/mL iodine content at the rates of 2 and 4 mL/s (p < 0.001). Qualitative assessment revealed significantly higher mean scores for the 370 mgI/mL groups than the 300 mgI/mL groups and significantly higher mean scores for the 4 mL/s groups than the 2 mL/s groups (p < 0.05). CONCLUSIONS: The optimal contrast protocol for BSCTA suggests that high iodine material concentration and high injection rate should be used for strong arterial attenuation and great visualization of the intracranial arterial structure in dogs.

Intramural esophageal location of a portosystemic shunt in a dog with two congenital portosystemic shunts on CT angiography.

A 5-year-old male neutered pug with hematuria was presented to a referral hospital after identification of an extrahepatic portosystemic shunt (EHPSS) during abdominal ultrasonography. Computed tomographic-angiography revealed two anomalous blood vessels (left gastroazygous and left gastrophrenic). The left gastroazygous vessel followed an atypical path within the dorsolateral esophageal wall before entering the azygous vein. The morphology of this highly unusual vessel has not, based on the authors' review of the literature, been previously reported. In combination with a second anomalous vessel, this resulted in a unique presentation of an EHPSS. Computed tomography-angiography was essential for diagnosis and surgical planning in this case.

Computed tomography angiography aids in predicting resectability of isolated liver tumors in dogs.

OBJECTIVE: To assess the accuracy of CT angiography (CTA) in predicting resectability, degree of surgical difficulty, and individual factors that may impact resectability of isolated hepatic masses in dogs. ANIMALS: Prospective study of 20 dogs with 21 isolated hepatic masses. PROCEDURES: All CTAs and surgeries were performed between June 16, 2013, and November 30, 2016, at The Animal Medical Center in New York. Preoperative CTA images were evaluated by a board-certified surgeon (n = 2). A preoperative assessment was completed, documenting several predetermined factors aimed at predicting resectability of each mass and the degree of surgical difficulty. Resectability was divided into gross resectability and complete histologic excision. Following surgery, the surgeon completed a postoperative assessment documenting the intraoperative findings. Independently, a blinded board-certified radiologist analyzed the images and completed an identical preoperative assessment. RESULTS: The radiologist was more accurate in lesion localization compared to the surgeon (P = .023). Seventeen (17/21) masses were grossly resectable in surgery. Two additional (2/21) masses that were deemed grossly resectable were incompletely excised on histopathologic analysis. Both the surgeon and radiologist were accurate in their prediction of gross resectability and complete excision. Major vascular involvement, multilobar involvement, and right-sided laterality negatively affected resectability. The surgeon was significantly more accurate in predicting the degree of surgical difficulty (κ = 0.50) when compared to the radiologist (κ = 0.38). CLINICAL RELEVANCE: Preoperative CTA of isolated hepatic masses is useful in prediction of surgical difficulty and resectability, as well as identifying several factors that impact resectability.

Effect of different injection rates and doses of contrast medium on the image quality of computed tomographic angiography in African grey parrots (Psittacus erithacus).

BACKGROUND: Atherosclerosis is a common cardiovascular disease in parrots but the antemortem diagnosis is challenging. In human medicine, computed tomography angiography (CTA) has been used widely for the diagnosis of atherosclerosis. By adjusting the injection rate and total dose of contrast medium, the image quality can be improved. To test the effects of different injection conditions on the image quality of major arteries, 10 African grey parrots (Psittacus erithacus) were used. Three injection rates (0.3, 0.4, 0.5 mL/s) and three doses (740, 370, 222 mg of iodine/bird) were tested while the other variables of the studies were fixed. RESULT: A higher injection dose led to a significantly higher attenuation, image noise and diameter, with a lower signal-to-noise ratio and contrast-to-noise ratio of the six major arteries. The 370 mg of iodine/bird group showed significantly better subjective image quality. Furthermore, with increasing injection rates, the prevalence of heterogeneity decreased. However, we found an increased risk of injection failure for the 0.5 mL/s groups. CONCLUSION: We recommend a combination of 370 mg of iodine/bird with 0.4 mL/s for clinical use to achieve better image quality for CTA.

Factors influencing enhancement timing in a triple-phase abdominal CT angiography protocol in dogs.

OBJECTIVE: To evaluate the enhancement accuracy of a triple-phase abdominal CT angiography (CTA) protocol in dogs and explore the patient, scan, and contrast parameters associated with accuracy of enhancement. ANIMALS: 233 client-owned dogs that underwent routine abdominal CTA. PROCEDURES: During each CTA study, the subjective timing accuracy (early, ideal, late) of the 3 obtained vascular phases (arterial, venous, delayed) was scored by consensus (2 reviewers) at 4 target organs (liver, pancreas, left kidney, and spleen). These scores were evaluated for statistical associations with 21 study variables (patient, scan, and contrast medium). The objective enhancement (HU) for each target organ was also compared statistically with subjective timing accuracy scores and the study variables. RESULTS: The study protocol performed best for the pancreas, moderately for the liver, and worse for the spleen and left kidney. Measurements of scan length and time were associated positively with phase lateness for most target organs and phases. Increased heart rate was the most significant patient factor associated positively with phase lateness within the liver (all phases), pancreas (arterial and venous phases), and kidney (arterial phase). Contrast medium variables were less associated with timing accuracy in this protocol. Objective enhancement (HU) correlated poorly with subjective phase timing accuracy and study variables. CLINICAL RELEVANCE: Scan time, scan length, and heart rate were the predominant variables contributing to lateness in this canine abdominal CTA protocol. The findings of this exploratory study may aid in protocol adjustment and choice of included anatomy for dogs undergoing routine abdominal CTA.

Percutaneous transvenous coil embolization of congenital intrahepatic portosystemic shunts in small- and toy-breed dogs: 20 cases (2015-2021).

OBJECTIVE: To describe outcomes of small- and toy-breed dogs with a congenital intrahepatic portosystemic shunt (IHPSS) treated with percutaneous transvenous coil embolization (PTCE). ANIMALS: 20 small- and toy-breed dogs with an IHPSS. PROCEDURES: All dogs underwent CT angiography for shunt evaluation as well as PTCE. Medical records were reviewed for pertinent data, and owners and primary veterinarians were contacted for long-term follow-up information. RESULTS: Dogs ranged from 1.5 to 10.0 kg (mean ± SD, 6.32 ± 2.57 kg) in weight. The equipment used to perform PTCE tended to be smaller than that previously described for larger breed dogs. Intra- and postoperative complication rates were 20% (4/20) and 5% (1/20), respectively, and included hypotension, bradycardia, hypercapnia, ventricular premature contractions, hypothermia, and regurgitation. Dogs were discharged a median of 3 days (range, 1 to 3 days) after surgery, and all dogs survived to discharge. Clinical signs resolved in 95% (19/20) of the dogs a median of 21 days after the procedure. One- and 2-year survival rates were 92%. Three dogs had died by the time of data collection; 2 of these dogs died of causes related to the IHPSS 267 and 1,178 days, respectively, after the procedure. CLINICAL RELEVANCE: Percutaneous transvenous coil embolization was a safe and effective option for treatment of IHPSS in small- and toy-breed dogs and offered a minimally invasive alternative to open surgical techniques. Complication and survival rates in this cohort were similar to or better than those reported in previous studies evaluating PTCE and open surgical techniques for treatment of IHPSS in dogs.

Unilateral external jugular vein aneurysm in a dog.

An 11-month-old Staffordshire Bull Terrier was referred with a two-month history of fluctuating unilateral jugular groove swelling, which appeared to enlarge after exercise. There was no history of trauma. Multimodal imaging findings (using transdermal and transesophageal ultrasound and dual phase computed tomography angiography) were consistent with large, saccular, left jugular vein aneurysm, running parallel to the left carotid artery. There did not appear to be any arteriovenous communication present. There were no cardiac abnormalities found on echocardiography. Following surgical excision, histopathological analysis supported the clinical suspicion of a congenital external jugular venous aneurysm.

Medial insertion of the patent ductus arteriosus characterized by computed tomography angiography in a cat and dog.

Surgical ligation of a left-to-right shunting patent ductus arteriosus was attempted in two animals. In both cases, a young cat and dog, ligation was complicated by poor visualization of the ductus resulting in unsuccessful ligation. Post-operatively, both the cat and dog underwent computed tomography angiography to characterize the location and morphology of the patent ductus arteriosus. In both cases, computed tomography angiography revealed a left-to-right shunting patent ductus arteriosus with an insertion location medial to the left pulmonary artery branch compared to the typical location. We hypothesize that this atypical location resulted in a difficult surgical visualization from the left thoracotomy approach. Transvenous coil embolization of the duct from the external jugular vein was performed in both cases and resulted in successful occlusion. Variations in the medial-lateral insertion of the ductus arteriosus may have consequences for surgical intervention. If an atypical location of a patent ductus arteriosus is suspected on transthoracic echocardiography, computed tomography angiography prior to ligation may be useful to further define ductal location and help guide the surgical approach.

A common celiacomesenteric trunk is a rare anatomic variant in dogs.

With the increasing use of CT and MRI for diagnostic imaging and planning of interventional procedures, it is important for veterinary radiologists to be familiar with variations in normal vascular anatomy and not mistake them for pathology. The arterial blood supply to the cranial abdominal viscera is provided by the celiac and the cranial mesenteric arteries. A common celiacomesenteric trunk (CMT) has been reported as a rare anatomical variant in dogs. The goals of this retrospective, observational, cross-sectional prevalence study were to determine the prevalence of a CMT in dogs with non-abdominal disease and compare it to the prevalence in dogs with portosystemic shunts (PSS). Magnetic resonance imaging studies of the thoracolumbar and lumbosacral spine in dogs that included the origin of the celiac and cranial mesenteric arteries and dual-phase CT angiography studies of the abdomen in dogs with portosystemic shunts were retrospectively reviewed by a veterinary student and a board-certified veterinary radiologist. The prevalence of a CMT was determined as the proportion of dogs diagnosed with this vascular anomaly in the MRI and CT group, respectively. Fisher's exact test was used to determine any association of a CMT with the concurrent presence of a PSS, sex, and breed size. A CMT was identified in seven of 606 (1.2%) MRI studies and in none of 47 abdominal CT studies. There was no association between the presence of a CMT and PSS (P = 1.000), sex (P = .4694), or breed size (P = 1.000). A CMT is a rare incidental finding in dogs.

Development of a method to measure regional perfusion of the lung in anesthetized ponies using computed tomography angiography and the maximum slope model.

OBJECTIVE: To develop a method based on CT angiography and the maximum slope model (MSM) to measure regional lung perfusion in anesthetized ponies. ANIMALS: 6 ponies. PROCEDURES: Anesthetized ponies were positioned in dorsal recumbency in the CT gantry. Contrast was injected, and the lungs were imaged while ponies were breathing spontaneously and while they were mechanically ventilated. Two observers delineated regions of interest in aerated and atelectatic lung, and perfusion in those regions was calculated with the MSM. Measurements obtained with a computerized method were compared with manual measurements, and computerized measurements were compared with previously reported measurements obtained with microspheres. RESULTS: Perfusion measurements obtained with the MSM were similar to previously reported values obtained with the microsphere method. While ponies were spontaneously breathing, mean ± SD perfusion for aerated and atelectatic lung regions were 4.0 ± 1.9 and 5.0 ± 1.2 mL/min/g of lung tissue, respectively. During mechanical ventilation, values were 4.6 ± 1.2 and 2.7 ± 0.7 mL/min/g of lung tissue at end expiration and 4.1 ± 0.5 and 2.7 ± 0.6 mL/min/g of lung tissue at peak inspiration. Intraobserver agreement was acceptable, but interobserver agreement was lower. Computerized measurements compared well with manual measurements. CLINICAL RELEVANCE: Findings showed that CT angiography and the MSM could be used to measure regional lung perfusion in dorsally recumbent anesthetized ponies. Measurements are repeatable, suggesting that the method could be used to determine efficacy of therapeutic interventions to improve ventilation-perfusion matching and for other studies for which measurement of regional lung perfusion is necessary.

Suspected contrast-induced nephropathy in three sequential patients undergoing computed tomography angiography and transarterial embolization for nonresectable neoplasia.

CASE DESCRIPTION: During the same week, 3 sequential patients (a 10-year-old 8.7-kg spayed female poodle cross [dog 1], 13-year-old 2.6-kg spayed female domestic longhair cat, and 13-year-old 9.0-kg castrated male mixed-breed dog [dog 2]) underwent CT-angiography (day 0) and transarterial embolization (day 1) for nonresectable hepatocellular carcinoma (n = 2) or prostatic carcinoma (1). CLINICAL FINDINGS: Contrast-induced nephropathy (CIN) was suspected in all animals on the basis of higher serum creatinine concentrations after contrast medium administration (exposure), compared with baseline concentrations before exposure, consistent with CIN definitions. The total dose of contrast medium was < 3 mL/kg for each exposure. For all 3 patients, creatinine concentration peaked at a median of 3 days (range, 2 to 3 days) after the first exposure (day 0), and the median absolute and relative increases in creatinine concentration after exposure (vs baseline concentrations before exposure) were 2.9 mg/dL (range, 2.2 to 3.7 mg/dL) and 410% (range, 260 to 720%), respectively. TREATMENT AND OUTCOME: The patients received individually tailored supportive care for acute kidney injury. Serum creatinine concentrations began to improve at a median of 4 days (range, 3 to 4 days) and returned to within reference limits at a median of 7 days (range, 3 to 13 days) following initial exposure. CLINICAL RELEVANCE: CIN should be considered as a potential complication following IV administration of contrast medium. Short-term outcome following CIN can be excellent with supportive care.

Optimal placement of the region of interest for bolus tracking on brain computed tomography angiography in Beagle dogs.

This study aimed to determine the optimal placement of the region of interest (ROI) among four anatomical sites-pulmonary artery (PA), pulmonary vein (PV), aortic arch (AA), and carotid artery (CA)-in computed tomography (CT) brain angiography with automatic bolus tracking in healthy beagle dogs. Six beagles were included, and CT brain angiography was performed four times for each dog, to cover each ROI. The scan parameters, amount, and injection rate of the contrast medium were the same. The major intracranial arteries were selected for quantitative and qualitative evaluation: caudal cerebellar artery (CcA), basilar artery (BA), rostral cerebellar artery (RcA), caudal cerebral artery (CCA), middle cerebral artery (MCA), and rostral cerebral artery (RCA). Quantitative evaluation showed significantly higher CT attenuation values for the RcA, CCA, and MCA in the PA group and RcA and MCA in the PV group than in the CA group. Qualitative analysis revealed significantly higher scores for the BA, CCA, and MCA in the PA and PV groups than in the CA group. Venous contamination did not differ significantly among the ROIs, but the mean scores of the AA and CA groups were higher than those of the PA and PV groups. CT brain angiography using bolus tracking in the beagle dogs showed that the ROI should be placed at the PA or PV rather than at the CA for optimal images with strong contrast enhancement of the BA, RcA, CCA, and MCA and minimal venous contamination.

Single left coronary ostium with a prepulmonic right coronary artery course in a French Bulldog with congenital valvular pulmonary stenosis.

A two-year-old, male castrated, French bulldog was presented for evaluation of coronary artery anatomy before balloon valvuloplasty for severe pulmonic valve stenosis. Multidetector computed tomography angiography showed a single left coronary ostium, absent right coronary ostium, and an anomalous, prepulmonic coursing right coronary artery. Medical management was elected to avoid the attendant risk associated with intervention. This case report documented the first known case of this specific anomaly in French bulldogs. Veterinary cardiologists should be aware of the potential for this specific coronary artery anomaly in this breed, given the predilection for the development of pulmonary stenosis. Routine screening of French bulldogs for anomalous, prepulmonic coronary arteries is recommended before interventional balloon valvuloplasty.

The appearance of canine insulinoma on dual phase computed tomographic angiography.

OBJECTIVES: To further evaluate the appearance of insulinoma in dogs on dual-phase CT angiography, given the disparity of findings in recent publications. To establish whether CT angiographic localisation of insulinoma correlates with surgical findings. MATERIALS AND METHODS: Single centre study of dogs with a final diagnosis of insulinoma which underwent abdominal CT angiography. Scans were retrospectively re-evaluated for specific features by two board-certified veterinary radiologists. These findings were also subsequently compared to surgical and histopathological reports to determine the accuracy of lesion localisation on CT. RESULTS: Thirty-five cases were included in final analysis, with pancreatic nodules identified in 33. Twenty-one were confirmed as insulinoma with histopathology. Jack Russell Terriers were over-represented. Twenty of 21 cases with confirmed insulinoma and 27 of 33 overall showed hyperattenuation in the arterial phase. The mean size of pancreatic insulinoma on CT was 15.1 mm, and 18.2% were larger than 20 mm. Eighteen of 21 confirmed and eight of 12 suspected insulinomas caused a deformation of the pancreatic shape, with two only identified as a result of this feature as these lesions were isoattenuating throughout the study. Pancreatic insulinoma location at surgery matched that described on the CT images in 17 of 19 cases where location was described in the surgical report. CLINICAL SIGNIFICANCE: In contrast to recent publications, this study suggests hyperattenuation of insulinomas in the arterial phase is a predominant feature, and that hypoattenuation or isoattenuation are much less common. CT angiography is accurate in prediction of lesion location before surgery in most cases.