Board-certified Veterinary Radiologist Research Articles

Prevalence of middle ear effusion in French bulldogs without clinical signs of otic disease: A retrospective study of magnetic resonance imaging (2017-2022).

Canine middle ear effusion (MEE) is usually asymptomatic, being an incidental finding when computed tomography or magnetic resonance imaging (MRI) of the head is performed for other reasons unrelated to otic disease. The clinical relevance of the presence of material in the tympanic bulla (TB) remains uncertain, and more detail about its prevalence and appearance in MRI are required. To assess the prevalence of presence of material within the TB of French bulldogs (FB) with no clinical signs suggestive of otitis (externa, media or interna) that underwent high-field MRI for other medical reasons. Two hundred fifty-two TB of 126 FB were included in this study. Nonexperimental retrospective study in which MRI images were evaluated by a board-certified veterinary radiologist. Fifty-eight per cent of the dogs had material in the TB lumen (46% of the TB) and 59% were bilaterally affected. The signal intensity of this material related to the grey matter was variable on T1w and mainly hyperintense on T2w sequences. FB are predisposed to MEE. This is important when assessing imaging studies of TB of FB with chronic otitis externa, as high percentage of cases may have concurrent MEE. MRI findings in FB with MEE are characterised by a hyperintense signal to the grey matter on T2w in most cases and variable on T1w sequences.

Presumed mediastinal cysts have a low prevalence in canine thoracic computed tomographic studies.

Mediastinal cysts (MCs) are rare lesions that can arise from embryonic remnants of various mediastinal structures. MCs usually are incidental findings in dogs and cats; however, they can reach a mass-like appearance. The description of MCs on CT in dogs is limited. This retrospective, single-center, descriptive, prevalence study aimed to determine the prevalence of presumed mediastinal cysts (PMCs) in dogs and assess their CT characteristics. Dogs that underwent a thoracic CT scan from January 2019 to August 2021 were included. CT images were evaluated for the presence of PMCs by two diagnostic imaging interns, two last year diagnostic imaging residents, and a board-certified veterinary radiologist. Number, location, margins, shape, volume, size, mass effect, and attenuation values of PMCs were assessed. A total of 866 CT scans were reviewed, and 49 PMCs were identified. The prevalence of PMCs in dogs was 5.66%. English Bulldog and mixed-breed dogs were subjectively overrepresented; however, the possibility of population bias could not be excluded. PMCs were subjectively more frequently observed in male dogs. The PMCs were predominantly round, small, solitary fluid-filled findings localized in the cranioventral mediastinum, with well-defined margins, homogeneous attenuation, and no contrast enhancement. The median attenuation value was 6.32 HU (range: -20.16 to 23.45 HU) precontrast and 7.58 HU (range: -2.45 to 20.79 HU) postcontrast, and the median volume was 1.19 cm3 (range: 0.02-45.32 cm3). Although the prevalence of PMCs was low in our sample population, findings supported prioritizing a differential diagnosis of incidental PMC for dogs with the above imaging characteristics.

Virtual non-contrast images of detector-based spectral computed tomography in dogs: a promising alternative to true non-contrast images in veterinary medicine.

In veterinary medicine, abdominal computer tomographic (CT) examinations regularly require a minimum of two scans, with a native scan (true unenhanced, TUE) as a reference for the subsequent contrast-enhanced CT scan (CECT). Spectral detector CT (SDCT) offers the possibility to calculate virtual non-contrast (VNC) images from the post-contrast scan, but this has not yet been investigated in veterinary medicine. The purpose of this study was to assess the reliability of VNC images for abdominal organs in 44 dogs without abdominal pathologies by evaluating their quantitative and qualitative parameters compared to TUE images. We hypothesized that the subtraction of iodine is sufficient in the VNC series compared to the TUE series and that the image quality of the SDCT series is superior to conventional CT images. Corresponding attenuation values in the VNC and TUE series regarding the regions of interest (ROI) in different parenchymal organs and major vessels of the abdominal cavity were assessed by means of a two one-sided t-test (TOST) and Bland-Altman plots. Additionally, the signal-to-noise ratio (SNR) was calculated for each ROI in the different series. In the second step, two board-certified veterinary radiologists made a qualitative assessment of VNC images vs. TUE images in consensus by rating the iodine subtraction, image noise, and image quality of VNC images based on a specific 5-point Likert scale. The difference in corresponding Hounsfield units (HUs) between TUE and VNC images was less than 10 HU in 78.67% of all ROIs. Regarding the limit of less than 10 HU, in the performed TOST, significant p-values of < 0.05 were reached for the liver, spleen, pancreas, and musculature, implying equivalence of both modalities. The quality of spectral base image (SBI) data was rated equivalent to calculated conventional images in the subjective assessment by reaching an average Likert scale score of 3.2 points. VNC images calculated from SDCT data prove a valid alternative to conventional TUE images in the abdominal organs of canine patients without abdominal pathology. VNC offers the possibility to reduce time under general anesthesia and minimize radiation exposure. Future studies are needed to prove the application of this method in clinically diseased patients.

Abdominal computed tomography and exploratory laparotomy have high agreement in dogs with surgical disease.

To compare the results of abdominal CT with exploratory laparotomy in the dog. 100 client-owned dogs from 1 academic institution. Medical records were searched for dogs that had undergone a preoperative abdominal CT scan read by a board-certified veterinary radiologist followed by an exploratory laparotomy. CT and surgical reports were compared. The overall agreement between abdominal CT scan and exploratory laparotomy in all cases was 97%. Overall, there was no evidence that proportion agreement differed on the basis of body condition score, time interval between CT and surgery, or oncologic versus nononcologic disease. Abdominal CT scan read by a board-certified diplomate is a sensitive presurgical diagnostic tool for surgical abdominal disease in the dog. When performing a specific abdominal surgery, it is acceptable for the surgeon to fully explore the abdomen or forego it for a smaller approach to the organ of interest if an abdominal CT was performed prior.

Cavitary pulmonary lesion wall thickness, presence of additional nodules, and intralesional contrast enhancement are associated with malignancy in dogs and cats.

To investigate the CT features of cavitary pulmonary lesions and determine their utility to differentiate malignant from benign lesions. This retrospective study included cases from 5 veterinary medical centers between January 1 2010, and December 31, 2020. Inclusion criteria included having a gas-filled cavitary pulmonary lesion on thoracic CT and definitive diagnosis by either cytology or histopathology. Forty-two animals (27 dogs and 15 cats) were included in this study. Medical records systems/imaging databases were searched, and cases meeting inclusion criteria were selected. The CT studies were interpreted by a third-year radiology resident, and findings were reviewed by a board-certified veterinary radiologist. 7 of the 13 lesion characteristics investigated were not statistically associated with the final diagnosis of the lesion, whereas 6 were statistically associated. Those that were associated included the presence of intralesional contrast enhancement, type of intralesional contrast enhancement (heterogenous and homogenous analyzed separately), presence of additional nodules, wall thickness of the lesion at its thickest point, and wall thickness at the thinnest point. Results from the present study showed that thoracic CT imaging of cavitary pulmonary lesions can be used to further refine the list of differential diagnoses. Based on this data set, in lesions that have heterogenous contrast enhancement, additional pulmonary nodules, and wall thickness > 40 mm at their thickest point, it would be reasonable to consider malignant neoplastic disease higher on the list of differentials than other causes.

Brucella canis discospondylitis in 33 dogs.

To describe the clinical and imaging findings of 33 dogs with Brucella canis discospondylitis (BDS). 33 client owned dogs from four veterinary specialty hospitals within Colorado and Arizona with at least one positive B. canis test and spinal diagnostic imaging. Retrospective review of signalment, physical and neurological examination findings, laboratory results, B. canis serology, and diagnostic imaging of 33 dogs with BDS. All imaging was reviewed by a board-certified veterinary neurologist. Radiographs were reviewed by a board-certified veterinary radiologist blinded to MRI and CT findings. 31/33 (94%) dogs were <5 years old (median = 2.5 years, mean = 2.9 years, range 0.5-10 years). 21/29 (72%) dogs had signs of nonspecific pain, spinal pain, or lameness for >3 months (median = 6 months, mean = 8.2 months, range 5 days-4 years). Fever was seen in only 4/28 (14%) dogs. Multifocal lesions were evident on radiographs in 21/29 (72%) dogs and MRI in 12/18 (67%) dogs. Smooth, round, central end-plate lysis, defined as "hole punch" lesions, were identified radiographically in 25/29 (86%) dogs. Vertebral physitis or spondylitis without discitis was evident on MRI in 7/18 (39%) dogs. Dogs with BDS typically present at a young age with a long duration of clinical signs. Identification of radiographic "hole punch" lesions and MRI evidence of vertebral physitis, spondylitis, and paravertebral inflammation without discitis should increase suspicion for BDS. BDS may be increasing in frequency in the southwestern United States, and dogs with signs of chronic spinal pain and/or lameness should be screened for B. canis.

Comparison of skeletal scintigraphy and standing 18 F-NaF positron emission tomography for imaging of the fetlock in 33 Thoroughbred racehorses.

This retrospective, methods comparison study aimed to compare skeletal scintigraphy and 18 F-NaF positron emission tomography (PET) for the detection of abnormalities in the fetlocks of Thoroughbred racehorses. Thirty-three horses (72 limbs) imaged with both scintigraphy and 18 F-NaF PET, for investigation of lameness or poor performance related to the fetlock, were included. Seven observers, including experienced racetrack practitioners, surgery and imaging residents, and a board-certified veterinary radiologist, independently reviewed all data for evidence of increased radiopharmaceutical uptake in 10 different regions of interest. The interobserver agreement was higher for PET (Kappa-weighted (K-w) 0.73 (0.51-0.84)) (median (range)) than for scintigraphy (0.61 (0.40-0.77)) (P<0.0001). When scintigraphy and PET were compared, the agreement was fair (K-w 0.29). More sites of increased uptake were identified using PET compared with scintigraphy. Agreement between the two modalities was higher for the palmar/plantar metacarpal/metatarsal condylar regions (K-w 0.59) than for the proximal sesamoid bones (K-w 0.25). Increased radiopharmaceutical uptake was detected in the medial proximal sesamoid bone in 6.9% and 22.2% of limbs with scintigraphy and PET, respectively. The high interobserver agreement for PET, despite the recent introduction of this technique, demonstrates the ease of clinical interpretation of PET scans. The higher number of lesions detected with PET compared with scintigraphy can be explained by the higher spatial resolution and cross-sectional nature of this modality. Study findings supported using PET in a clinical population of racehorses, in particular for the assessment of the proximal sesamoid bones.

MRI characteristics of canine prostatic neoplasia.

Magnetic resonance imaging (MRI) has been used to evaluate dogs with suspected prostatic neoplasia, however, published studies describing MRI characteristics of canine prostatic neoplasia are currently lacking. The aims of the current retrospective case series study were to describe MRI findings of the pelvic region in dogs with a histopathologic or cytologic diagnosis of prostatic neoplasia. Retrospective analysis of these images was then performed by a board-certified veterinary radiologist for shared imaging characteristics. The most consistent characteristics were heterogeneous hyperintensity of the tumor on T2-weighted images (10/10) and short tau inversion recovery images (10/10), prostatic capsular margin distortion by the tumor (10/10), cavitations (10/10), complete effacement of the prostatic architecture (9/10), neurovascular bundle (NVB) compression or invasion (9/10), heterogeneous isointensity of the tumor on T1-weighted images (9/10), and strong contrast enhancement of the tumor (8/10). Additional features included an overlying pattern of distorted radiating striations (7/10), regional lymphadenomegaly (5/10), mineralization within the mass (5/10), urinary bladder trigone involvement (6/10), and post-prostatic urethral involvement (7/10). These findings supported the use of MRI as an adjunct imaging modality for diagnosis and therapeutic planning of prostatic neoplasia and including prostatic neoplasia as a likely differential diagnosis for dogs with these MRI characteristics.

CT features of subcutaneous, intermuscular, and intramuscular mast cell tumors in dogs.

Surgical removal is the treatment of choice for subcutaneous (SC), intermuscular (InterM), and intramuscular (IntraM) mast cell tumors (MCTs). Advanced imaging (CT or MRI) is frequently used for presurgical planning, but InterM and IntraM MCTs can be difficult to identify and delineate on CT. Aims of the current retrospective, diagnostic accuracy, observer agreement study were to describe the imaging features of SC, InterM, and IntraM MCTs on CT and to assess the limitation of CT to identify the full local extent of the MCT. Inclusion criteria for the study were dogs with a cytologically or histologically diagnosed MCTs determined to be SC, InterM, or IntraM MCT based on histology and/or a CT scan performed in the gross disease setting. Two board-certified veterinary radiologists reviewed the CT images and recorded location, contrast enhancement pattern, and delineation between the normal and abnormal tissue. Sensitivity and specificity of CT for determining location (SC/InterM versus IntraM) was 85.71% and 55.56%, respectively, when compared to consensus location based on surgical pathology report/CT/MRI review. There was a low inter-rater agreement for delineation (kappa: 0.150 (-0.070 to 0.370) and measurement had a low/moderate correlation (rho: 0.4667 to 0.5792). Upon review by a surgical oncologist, CT findings were deemed insufficient for curative surgical planning in 13 of 16 due to inadequate definition of tumor depth, compartment boundary (fascial plane) or MCT margins. The use of CT for presurgical planning of SC/InterM/IntraM MCT dogs has limitations, especially when differentiating MCT from the adjacent muscle.

Staging canine patients with appendicular osteosarcoma utilizing fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography compared to whole body computed tomography.

Few studies have investigated the diagnostic performance of fluorine-18-fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) for staging veterinary patients with appendicular osteosarcoma. The purpose of this study was to evaluate the efficacy of 18 F-FDG-PET/CT compared to whole-body CT (WBCT) for staging canine patients with appendicular osteosarcoma. The 18 F-FDG-PET/CT imaging studies of 66 dogs with appendicular osteosarcoma were anonymized and separated into two detached studies (one with whole body pre- and post-contrast CT images and the other with the whole body pre- and post-contrast CT images with the associated 18 F-FDG-PET overlay). Image assessment was performed retrospectively by five board-certified veterinary radiologists. The radiologists were instructed to assign a predefined categorical score (1-4) to each pre-designated anatomic region based on a devised lesional scoring system. A score of 1 was normal, 2 abnormal but not neoplastic, 3 abnormal and concerning for neoplasia, and 4 abnormal, most likely neoplastic. Overall, the likelihood of detection of '3 or 4' was found to be significantly higher with 18 F-FDG PET/CT when compared to WBCT after adjusting for the effect of evaluator and the subject. Most significantly, 13 osseous lesions concerning for metastasis (scored 3-4) were identified in 10/66 dogs by at least one reviewer on 18 F-FDG PET/CT, which were not identified by any reviewer on WBCT. Additionally, four comorbid neoplastic lesions were identified with 18 F-FDG PET/CT and not with WBCT. The results of this study suggest that 18 F-FDG PET/CT is more efficacious in detecting metastatic and comorbid neoplastic lesions compared to WBCT in dogs with appendicular osteosarcoma.

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.

Prevalence of Brain Magnetic Resonance Imaging Diagnoses and Correlation With Signalment and Presenting Complaint in Dogs.

Since magnetic resonance imaging (MRI) was introduced, it has become increasingly available and technologically improved. Studies have documented the prevalence of specific pathologies, however no previous veterinary studies have investigated the prevalence and distribution of pathology across all MRIs performed at a single institution. The present study aimed to evaluate the prevalence of MRI-diagnosed brain lesions and correlate these to patient signalment and presenting complaint. Archived MRI brain scans from 805 dogs were reviewed retrospectively. One board-certified veterinary radiologist at the institution retrospectively evaluated all reports to determine the most clinically pertinent imaging diagnosis for each case. Breed, age, and presenting complaint were obtained from the medical record for each patient. The most common imaging diagnoses across all dogs reviewed were no significant findings (35.16%), asymmetric encephalopathy or meningoencephalopathy (19.75%), and extra-axial intracranial mass (11.18%). Age of dogs differed by diagnosis (p <0.0001), with the median age of dogs diagnosed with a brain mass being greater than that of dogs with no significant findings and dogs with asymmetric encephalopathy or meningoencephalopathy (both p <0.0083). In dogs presenting with seizures, the odds of a brain mass increased with each additional year of age [p <0.0001, odds ratio 1.26 (95% CI 1.16–1.37)], whereas the odds of no significant finding [p <0.0001, OR 0.87 (0.82–0.93)] decreased. Our findings provide overview information on the types of disease observed in the clinical population and allow us to detect correlations between imaging diagnoses, presenting complaints, and signalment.

Abdominal ultrasound image quality is comparable among veterinary sonographers with varying levels of expertise for healthy canine and feline patients.

Abdominal ultrasonography is increasingly used as a standard diagnostic test in veterinary practices, however, there is little published information regarding the effects of operator experience on image quality. In this prospective observer agreement study, image quality was assessed for abdominal ultrasound examinations performed by nine sonographers (three general practitioners, three credentialed veterinary technicians, and three board-certified specialists). Each sonographer independently performed abdominal ultrasound examinations on the same group of 4 sedated clinically healthy animals (3 dogs, 1 cat) using the same model machine and standardized presets. Twenty-five organs and anatomical landmarks per exam (26 for male dog) were evaluated. Still images and cine loops were recorded for each one of the organs. The final scoring of image quality for each examination was performed by two board-certified veterinary radiologists in a randomized and blinded fashion. Semiquantitative scoring system was used for each reading: 0 - not seen, 1- seen but poor quality/partial seen, 2 - average/good quality, and 3 - excellent quality. The average score for each animal and sonographer was tallied and sonographer groups and individual sonographers were compared. Scores were assessed for normality and data were ranked transformed prior to statistical analysis. No significant differences were found regarding the completeness and quality scores of sonographers of different experience levels and disciplines when measuring specific standard components of a full abdominal scan. There were no statistical differences between individual sonographers or groups of sonographers. Although not statistically significant, the general practitioner's group showed the greatest variability of their individual scores.

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

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. 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. 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. 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.

Three-dimensional bladder ultrasound for estimation of urine volume in dogs compared with traditional 2-dimensional ultrasound methods.

BackgroundAlthough point‐of‐care volumetric assessments of the urinary bladder are not routinely performed in dogs, urine volume quantification can provide important clinical information including noninvasive urine output estimation.Hypothesis/ObjectiveUse of 3‐dimensional (3D) ultrasound for determination of urinary bladder volume (UBV) in dogs will be accurate for different bladder volumes and will decrease the need for operator skill in measuring UBV compared to 2‐dimensional (2D) ultrasound evaluation.AnimalsTen laboratory‐bred Beagle dogs.MethodsProspective, experimental study. Urinary bladders were infused with a calculated amount of sterile saline to represent small, medium, and large volumes. Each UBV was estimated and calculated by a board‐certified veterinary radiologist using 3 different 2D ultrasound formulas followed by use of a 3D ultrasound device by a novice. Measured UBVs were compared to the instilled UBV for both 2D and 3D ultrasound methods. Time from start to end of examination was recorded for both ultrasound methods in a subset of dogs.ResultsThe 3D ultrasound device underestimated UBV with a mean difference of −9.8 mL compared with 2D ultrasound that overestimated UBV with a difference of +4.2 to 20.3 mL dependent on the 2D formula used. The 3D ultrasound method took less time to measure UBV (mean of 80 seconds per measurement) compared to the 2D method (165 seconds per measurement; P = .02).Conclusions and Clinical ImportanceThe tested 3D ultrasound device was found to be an accurate and rapid point‐of‐care tool for measuring UBV in dogs, providing a noninvasive method to estimate bladder volume in real time.

Artificial intelligence evaluating primary thoracic lesions has an overall lower error rate compared to veterinarians or veterinarians in conjunction with the artificial intelligence

To date, deep learning technologies have provided powerful decision support systems to radiologists in human medicine. The aims of this retrospective, exploratory study were to develop and describe an artificial intelligence able to screen thoracic radiographs for primary thoracic lesions in feline and canine patients. Three deep learning networks using three different pretraining strategies to predict 15 types of primary thoracic lesions were created (including tracheal collapse, left atrial enlargement, alveolar pattern, pneumothorax, and pulmonary mass). Upon completion of pretraining, the algorithms were provided with over 22000 thoracic veterinary radiographs for specific training. All radiographs had a report created by a board-certified veterinary radiologist used as the gold standard. The performances of all three networks were compared to one another. An additional 120 radiographs were then evaluated by three types of observers: the best performing network, veterinarians, and veterinarians aided by the network. The error rates for each of the observers was calculated as an overall and for the 15 labels and were compared using a McNemar's test. The overall error rate of the network was significantly better than the overall error rate of the veterinarians or the veterinarians aided by the network (10.7%vs 16.8%vs17.2%, P=.001). The network's error rate was significantly better to detect cardiac enlargement and for bronchial pattern. The current network only provides help in detecting various lesion types and does not provide a diagnosis. Based on its overall very good performance, this could be used as an aid to general practitioners while waiting for the radiologist's report.

Sentinel lymph node detection differs when comparing lymphoscintigraphy to lymphography using water soluble iodinated contrast medium and digital radiography in dogs.

Sentinel lymph node (SLN) mapping by various means has become standard of care in certain types of human cancers and is receiving more attention in veterinary oncology. Current SLN mapping techniques can be costly and often require advanced imaging equipment. The objective of this prospective, method comparison study was to compare an SLN mapping protocol of lymphoscintigraphy to lymphography using water soluble iodinated contrast medium (WIC) and digital radiography for identification of an SLN. Lymphoscintigraphy and lymphography were performed on eight healthy purpose-bred dogs using technetium-99m sulfur colloid and WIC injected into the subcutaneous tissues in a four-quadrant technique around a predefined area of skin on the brachium. Images were obtained using a gamma camera and digital radiography at different time points post-injection. Image sequences were evaluated by one of two American College of Veterinary Radiology board-certified veterinary radiologists. Data obtained were compared between methods using descriptive statistics. An SLN was identified in all dogs with lymphoscintigraphy and seven of eight dogs with lymphography. Agreement between results of the lymphoscintigraphy and lymphography studies was a complete match in three dogs, a partial match in four dogs, and no match in one dog. The SLN detected differed based on the imaging modality used.

Radiographic features of histologically benign bone infarcts and bone infarcts associated with neoplasia in dogs.

To describe the radiographic appearance of benign bone infarcts and bone infarcts associated with neoplasia in dogs and determine the utility of radiography in differentiating benign and malignancy-associated bone infarcts. 49 dogs with benign (n = 33) or malignancy-associated (16) infarcts involving the appendicular skeleton. A retrospective cohort study was performed by searching a referral osteopathology database for cases involving dogs with a histologic diagnosis of bone infarction. Case radiographs were anonymized and reviewed by 2 board-certified veterinary radiologists blinded to the histologic classification. Radiographic features commonly used to differentiate aggressive from nonaggressive osseous lesions were recorded, and reviewers classified each case as likely benign infarct, likely malignancy-associated infarct, or undistinguishable. Only 16 (48%) of the benign infarcts and 6 (38%) of the malignancy-associated infarcts were correctly classified by both reviewers. Medullary lysis pattern and periosteal proliferation pattern were significantly associated with histologic classification. Although all 16 (100%) malignancy-associated lesions had aggressive medullary lysis, 23 of the 33 (70%) benign lesions also did. Eight of the 16 (50%) malignancy-associated infarcts had aggressive periosteal proliferation, compared with 7 of the 33 (21%) benign infarcts. Results suggested that radiography was not particularly helpful in distinguishing benign from malignancy-associated bone infarcts in dogs.

Schedule feasibility and workflow for additive manufacturing of titanium plates for cranioplasty in canine skull tumors

BackgroundAdditive manufacturing has allowed for the creation of a patient-specific custom solution that can resolve many of the limitations previously reported for canine cranioplasty. The purpose of this pilot study was to determine the schedule feasibility and workflow in manufacturing patient-specific titanium implants for canines undergoing cranioplasty immediately following craniectomy.ResultsComputed tomography scans from patients with tumors of the skull were considered and 3 cases were selected. Images were imported into a DICOM image processing software and tumor margins were determined based on agreement between a board-certified veterinary radiologist and veterinary surgical oncologist. Virtual surgical planning was performed and a bone safety margin was selected. A defect was created to simulate the planned intraoperative defect. Stereolithography format files of the skulls were then imported into a plate design software. In collaboration with a medical solution centre, a custom titanium plate was designed with the input of an applications engineer and veterinary surgery oncologist. Plates were printed in titanium and post-processed at the solution centre. Total planning time was approximately 2 h with a manufacturing time of 2 weeks.ConclusionsBased on the findings of this study, with access to an advanced 3D metal printing medical solution centre that can provide advanced software and printing, patient-specific additive manufactured titanium implants can be planned, created, processed, shipped and sterilized for patient use within a 3-week turnaround.

Non-electrocardiographic-gated computed tomographic angiography can be used to diagnose coronary artery anomalies in Bulldogs with pulmonary valve stenosis.

Coronary artery anomalies have been reported in Bulldogs and present an increased risk when performing balloon valvuloplasty. Identification of coronary anomalies has been reported using multidetector-row computed tomographic (MDCT) angiography with electrocardiographic gating. However, the utility of non-electrocardiographic-gated 16-row computed tomographic for MDCT for the identification of coronary artery anatomy or anomalies to the authors' knowledge has not been fully investigated. The purpose of this study was to evaluate the feasibility of non-electrocardiographic-gated computed tomographic (CT) angiography to identify coronary anomalies in Bulldogs with pulmonary valve stenosis. In this prospective, observational study, Bulldogs with echocardiographically diagnosed pulmonary valve stenosis, an echocardiographically derived transpulmonic pressure gradient >70mmHg, and a clinician recommendation for balloon valvuloplasty were included. Anesthetized dogs underwent a 16-row MDCT non-electrocardiographic-gated CT angiography. A board-certified veterinary radiologist and board-certified veterinary cardiologist reviewed the CT angiography studies and identified the coronary artery anatomy. When normal coronary artery anatomy was detected on CT angiography, a right ventricular outflow tract fluoroscopic angiogram was performed and evaluated during levophase to confirm normal coronary anatomy prior to balloon valvuloplasty. Dogs with coronary anomalies noted on CT angiography were recovered from anesthesia and balloon valvuloplasty was not performed. All dogs (10/10; 100%) had interpretable images from the non-electrocardiographic-gated CT angiography. Coronary anomalies were identified in six dogs based on non-electrocardiographic-gated CT angiography, five with type R2A anomaly and one had a single left coronary ostium. Four dogs had normal coronary anatomy based on non-electrocardiographic-gated CT angiography. Balloon valvuloplasty was performed without incident in these four dogs. We conclude that non-electrocardiographic-gated CT angiography represents a noninvasive method for diagnosing coronary anomalies in Bulldogs with pulmonary valve stenosis.