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Information on the clinical outcomes of feline azotemia using ultrasound examinations is limited. This study aimed to understand the correlation between cortical anisotropy backscattering artifact (CABA) and serum creatinine (sCr) changes in feline azotemia after hospitalization and to investigate whether CABA is useful for predicting the clinical outcome of feline azotemia. Sixty-five hospitalized cats with azotemia, including 49 cats with moderate or severe azotemia (severe group) and 16 cats with mild azotemia (mild group). This retrospective study reviewed the CABA using ultrasound images of cats hospitalized with azotemia between 2016 and 2021. The correlation between CABA and the clinical outcomes of cats with azotemia was investigated using the chi-squared or Fisher's exact test, and the intra- and inter-observer agreements in CABA were assessed using McNemar's and Cohen's kappa tests. The presence of CABA was significantly positively correlated with the clinical outcomes of cats with azotemia only in the severe group ( p  = 0.0034, odds ratio = 8.57). There was no association between CABA and clinical outcomes in cats with mild azotemia ( p  = 0.75). CABA can be used for clinical outcome prediction in moderate and severe feline azotemia, with a sensitivity of 80.8% and a specificity of 73.9%. Also, satisfactory intra- and inter-observer agreements were revealed in the detection of CABA during ultrasound image review. Our study demonstrated that cats with moderate and severe azotemia with CABA observed during ultrasonography might have better clinical outcomes. These findings provide additional information on the prognosis and treatment of feline azotemia.

A 9 yr old male miniature poodle presented with acute diarrhea, vomiting, and a distended abdomen. A large and firm mass was palpated in the caudal abdomen. Radiography showed a large soft-tissue mass in the mid ventral abdomen. The mass was mildly contrast-enhancing and in contact with the right cranial aspect of the bladder on computed tomography. The mass was heterogeneous with minimal blood flow on Doppler examination. Surgery confirmed its origin of the urinary bladder, and it was diagnosed leiomyosarcoma on pathology. This is the first report of extraluminal leiomyosarcoma of the bladder wall with imaging characteristics using various modalities., (© 2024 by American Animal Hospital Association.)

Hypoalbuminemia has been considered as a cause of gallbladder wall thickening in humans and dogs. Recent study revealed that gallbladder wall thickening in dogs with hypoalbuminemia may not be associated with serum albumin/plasma levels within 48 h of ultrasound study. However, gallbladder wall edema may change within 48 h, and the ultrasonographic features of gallbladder wall thickening in dogs with hypoalbuminemia have not been reported. The purpose of this study is to describe the relationship between serum albumin levels within 24 h of ultrasound and gallbladder wall thickening, and to describe the ultrasonographic features of thickened gallbladder walls in dogs with hypoalbuminemia. 37 hypoalbuminemic dogs with gallbladder ultrasound images were retrospectively included. Ultrasound studies were reviewed, and gallbladder wall thickness, layering appearance, echogenicity, echotexture, distribution, evidence of gallbladder mucocele, and presence of peritoneal effusion were recorded. Additionally, serum albumin levels within 24 h of ultrasound study and the administerd sedation were recorded. The prevalence of gallbladder wall thickening in dogs with hypoalbuminemia was 13.5%. The 3-layer appearance of the gallbladder wall was observed in 4 dogs, and a single-layer gallbladder wall thickening in one dog. Diffuse thickening was observed in all 5 dogs. The serum albumin level of dogs with gallbladder wall thickening was not different ( p  = 0.14) from dogs without thickening. Gallbladder wall thickening was not common, occurring only with mild hypoalbuminemia, and was commonly associated with a 3-layer appearance and considered as gallbladder wall subserosal edema. Causes other than hypoalbuminemia may be responsible for thickening of the gallbladder wall in dogs with hypoalbuminemia.

Approximately 27 million ducks are raised commercially in the US each year and Pekin ducks (Anas platyrhynchos domesticus) are the most commonly raised breed. Additionally, an increasing number of Americans are raising small flocks of poultry, which often include ducks, in their own backyards. This creates a need to better understand the imaging anatomy of ducks. However, in avian species, superimposition of organs limits evaluation of the coelomic cavity using the most common imaging modality, radiography. The use of cross-sectional imaging including computed tomography (CT) and magnetic resonance imaging (MRI) has increased in veterinary medicine research and clinical use. An anatomic atlas is essential for guiding research and diagnostic imaging. To date, no CT or MRI atlas exists for Pekin ducks. The purpose of the study is to generate a CT atlas of market-age Pekin ducks as well as CT attenuation values and measurements of coelomic organs with corresponding gross and MRI images. A total of 20 market-age, commercial Pekin ducks were imaged. Five male and five female ducks were imaged with CT; four of these ten ducks, two male and two female, were frozen and sliced in approximately 5 mm transverse sections for gross anatomic reference images. Six additional ducks, three male and three female ducks, were dissected to measure major organs. Four additional ducks were imaged using CT and MRI and necropsied for gross anatomical comparisons and landmarks. The atlas contained here may be used for future research projects and clinically to aid in diagnosis of disease in ducks., (© 2023 The Authors. Anatomia, Histologia, Embryologia published by Wiley-VCH GmbH.)

Retained surgical sponges or gauzes (RSS) are an uncommon complication of exploratory laparotomy surgery and pose a clinically significant risk to the patient. The purpose of this two-part, prospective, descriptive study was to describe the previously uncharacterized ultrasonographic appearance of RSS in phantom and cadaveric models of the acute postoperative period (24-48 h). For the first part of the study, a gelatin phantom containing a woven gauze with a radiopaque marker (radiopaque gauze), a woven gauze with no marker (nonradiopaque gauze), and a laparotomy sponge with a radiopaque marker (radiopaque sponge) was evaluated with ultrasonography. For the second part of the study, a total of 23 gauzes and sponges (of the aforementioned three types) were placed within the peritoneal cavity of 20 cadavers in one of three randomized locations during an exploratory laparotomy laboratory. The cadavers were imaged with ultrasonography 17 h later and still images and video clips were reviewed. The retained surgical sponges and gauzes in the gelatin phantom displayed multiple hyperechoic layers and variable degrees of distal acoustic shadowing. In cadavers, 100% (23/23) of the retained surgical sponges and gauzes displayed a single hyperechoic layer of variable thickness and distal acoustic shadowing. In 95.6% (22/23) retained sponges and gauzes, there was a thin hypoechoic layer noted superficially to the hyperechoic layer. An improved understanding of the ultrasonographic appearance of retained sponges or gauzes in the acute postoperative period may assist in the identification of these objects., (© 2023 American College of Veterinary Radiology.)

Background: Early detection and intervention research is expected to improve the outcomes for patients with high grade muscle invasive urothelial carcinoma (InvUC). With limited patients in suitable high-risk study cohorts, relevant animal model research is critical. Experimental animal models often fail to adequately represent human cancer. The purpose of this study was to determine the suitability of dogs with high breed-associated risk for naturally-occurring InvUC to serve as relevant models for early detection and intervention research. The feasibility of screening and early intervention, and similarities and differences between canine and human tumors, and early and later canine tumors were determined., Methods: STs (n=120) ≥ 6 years old with no outward evidence of urinary disease were screened at 6-month intervals for 3 years with physical exam, ultrasonography, and urinalysis with sediment exam. Cystoscopic biopsy was performed in dogs with positive screening tests. The pathological, clinical, and molecular characteristics of the "early" cancer detected by screening were determined. Transcriptomic signatures were compared between the early tumors and published findings in human InvUC, and to more advanced "later" canine tumors from STs who had the typical presentation of hematuria and urinary dysfunction. An early intervention trial of an oral cyclooxygenase inhibitor, deracoxib, was conducted in dogs with cancer detected through screening., Results: Biopsy-confirmed bladder cancer was detected in 32 (27%) of 120 STs including InvUC (n=29, three starting as dysplasia), grade 1 noninvasive cancer (n=2), and carcinoma in situ (n=1). Transcriptomic signatures including druggable targets such as EGFR and the PI3K-AKT-mTOR pathway, were very similar between canine and human InvUC, especially within luminal and basal molecular subtypes. Marked transcriptomic differences were noted between early and later canine tumors, particularly within luminal subtype tumors. The deracoxib remission rate (42% CR+PR) compared very favorably to that with single-agent cyclooxygenase inhibitors in more advanced canine InvUC (17-25%), supporting the value of early intervention., Conclusions: The study defined a novel naturally-occurring animal model to complement experimental models for early detection and intervention research in InvUC. Research incorporating the canine model is expected to lead to improved outcomes for humans, as well as pet dogs, facing bladder cancer., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Dhawan, Ramos-Vara, Utturkar, Ruple, Tersey, Nelson, Cooper, Heng, Ostrander, Parker, Hahn, Adams, Fulkerson, Childress, Bonney, Royce, Fourez, Enstrom, Ambrosius and Knapp.)

Postcontrast computed tomographic (CT) characteristics of gastrointestinal (GI) wall edema in humans have been described as GI wall thickening with a thickened submucosal layer and thin enhanced inner and outer layers. Published studies describing CT features of gastric wall edema in dogs are currently lacking. The aim of this retrospective, case series was to describe CT features of gastric wall edema in a group of dogs. Medical records were searched for dogs with postcontrast abdominal CT scans and a diagnosis of gastric wall edema based on histopathology (group I) or CT characteristics consistent with those reported in humans (group II). Clinical diagnosis, mean serum albumin concentration, and histopathological diagnosis were recorded. The following CT characteristics were recorded: numbers of wall layers, attenuation and contrast enhancement, presence of blood vessels, locations, distribution, and thickness. Twelve dogs (3 in group I and 9 in group II) were included. The most common clinical finding was hypoalbuminemia. In group I, a well-defined three-layer appearance with a non-enhancing fluid-attenuating middle layer was observed in three dogs and thin blood vessels in the middle layer in two dogs. In group II, nine dogs had a three-layer appearance with a non-enhancing fluid-attenuating middle layer. Locations of gastric wall thickening were diffuse in two, focal concentric in six, and focal asymmetric in four dogs. Findings supported including gastric wall edema as a differential diagnosis for dogs with hypoalbuminemia and CT characteristics of a three-layer appearance in the gastric wall, with a non-enhancing fluid-attenuating middle layer and thin blood vessels., (© 2022 The Authors. Veterinary Radiology & Ultrasound published by Wiley Periodicals LLC on behalf of American College of Veterinary Radiology.)

A geriatric female giant panda developed grave signs of illness and was diagnosed with suspected hepatobiliary tract obstruction or other severe hepatic disease such as advanced cholangiohepatitis. The giant panda was euthanized and post mortem computed tomography was performed prior to necropsy. Common bile duct obstruction at the major duodenal papilla by a mineral attenuating calculus causing dilatation of common bile and gallbladder with concurrent multiple areas of liver abscess were detected by postmortem computed tomography. These were confirmed with gross necropsy. This is the first case report of common bile duct obstruction by mineral calculus with concurrent severe cholangiohepatitis in a giant panda.

An apex nodule was recently identified in the urinary bladder of Scottish Terriers being screened for bladder cancer at our institution. This prospective, single-center, case series study was performed to better characterize the apex nodule and assess the clinical importance of the nodule. Scottish Terriers ≥6 years of age with no evidence of urinary tract disease underwent urinary tract ultrasonography and urinalysis at 6-month intervals. In dogs with evidence of the apex nodule, ultrasound features such as location, margins, number, echogenicity, size, and shape of the lesion were recorded by a veterinary oncologist and veterinary radiologist. The apex nodule was identified in eight (6%) of 134 dogs in the absence of other detectable bladder disease. Features of the nodules included the following: one nodule per dog, triangular to an oval shape, smooth mucosal covering, well-defined margins, isoechoic to the bladder wall, 2-4 mm at the base, and 4-6 mm protruding into the bladder lumen. In five dogs undergoing multiple ultrasonographic examinations, the nodule did not appear to change over time (up to 3.5 years). Cystoscopy performed in three dogs revealed a column of tissue covered by normal mucosa protruding into the bladder lumen. Histological features consistent with a neoplastic growth were absent. Five dogs remained free of any bladder disease. Three dogs developed urothelial carcinoma at sites distant to the nodule at 8-53 months after the nodule was first observed. Findings indicated that incidental apex nodules could mimic neoplasia and other bladder diseases in Scottish Terriers., (© 2022 American College of Veterinary Radiology.)

Background: The horizontal beam (HB) view has been used in the identification of pneumothorax, pleural effusion, and pneumoperitoneum in small animals. Based on the literature, there were no published data evaluating the utility of HB radiography in vomiting dogs to differentiate between patients with or without mechanical gastrointestinal ileus., Aim: The purpose of this prospective pilot study was to determine the utility of HB radiograph as an additional view in vomiting dogs to differentiate patients with or without mechanical gastrointestinal ileus; and describe if there are any radiographic image characteristics associated with the HB view for patients with mechanical gastrointestinal ileus., Methods: A prospective study was carried out on dogs presented with acute vomiting. For all dogs, four radiographic views [ventrodorsal (VD), right lateral, left lateral, and left-to-right lateral HB in sternal recumbency] of the abdomen and abdominal ultrasound were obtained. If a mechanical ileus was detected ultrasonographically, an exploratory laparotomy or endoscopy was performed, otherwise medical treatment was elected., Results: A total of 22 patients were recruited, 11 diagnosed with mechanical ileus and 11 without mechanical ileus. Three blinded reviewers independently assessed the radiographs in three sets: vertical beam (VB) views, HB view alone, and a combination of both views. No statistical difference was found in the differentiation between patients with or without mechanical gastrointestinal ileus between HB views alone or added to VB views., Conclusion: This study suggests that the HB view in sternal recumbency may be an alternative for patients who are not stable enough to be positioned in lateral or VD recumbency., Competing Interests: The authors declare that they have no conflict of interest. Fig. 3.Example of crowding organs at the ventral aspect of the abdomen in a left-to-right lateral HB view. Evaluation of the ventral abdomen is challenging due to presence of fluid/soft tissue-filled intestines and concurrent peritoneal effusion.

In collaboration with the American College of Veterinary Radiology.

Published findings on the computed tomographic (CT) appearance of sialoceles are limited to brief descriptions from reported cases in eight dogs and one cat. The authors have seen sialoceles with CT characteristics that are not consistent with these previous reports. The purpose of this multicenter, retrospective, descriptive, case series study was to provide more detailed descriptions of the CT appearance of confirmed sialoceles in dogs. Dogs over a 10-year period with cytologically or histologically confirmed sialoceles and pre- and postcontrast CT studies of the head were included. Multiple qualitative and quantitative features were described for each sialocele with histological correlation. Twelve dogs with a total of 13 sialoceles were identified, including: seven cervical sialoceles, three complex (combined cervical and sublingual) sialoceles, two sublingual sialoceles, and one zygomatic sialocele. All sialoceles were characterized by fluid attenuating, non-contrast enhancing contents (median 18.5 HU) and soft tissue attenuating, contrast-enhancing walls. The external margins of all sialocele walls were smooth; however, the internal margins in six sialoceles were irregular with poorly defined nodular to frond-like protrusions. Mineralized foci of variable size (range < 1 mm to 4.8 mm) and attenuation (range 119 to 1253 HU) were present in seven sialoceles and histologically identified as sialoliths (three sialoceles) and osseous metaplasia (two sialoceles). A unique finding in the sialoceles in this study was the presence of intraluminal nodular to frond-like protrusions arising from the wall. This study also reports the CT appearance of cervical and complex sialoceles and sialocele mineralizations., (© 2021 American College of Veterinary Radiology.)

Renal cortical anisotropy backscattering artifact (CABA) is a focal hyperechoic region where the tubules are parallel to the incident ultrasound beam, reflecting most of the beams to the transducer. To investigate the association between chronic kidney disease (CKD) and the absence of renal CABA in cats. Ultrasonographic renal images of 40 cats with CKD (stage II-IV) and 36 clinically healthy cats were blindly evaluated by two observers to determine the visibility of renal CABA. Inter- and intraobserver agreements were evaluated using McNemar's test. The association between the absence of renal CABA and CKD was assessed using Fisher's exact test. Excellent intraobserver and substantial interobserver agreements were demonstrated. A significant association ( P < .0001) between absent renal CABA and CKD stage was revealed in all cats. Cats with CKD had an increased risk of the absence of renal CABA (Odds ratio, 56.0; 95% CI, 13.8-227.0) compared with the clinically healthy cats. The absence of renal CABA revealed 87.5% sensitivity and 88.9% specificity to detect CKD in all cats, and 91.7% sensitivity and 83.3% specificity in aged cats. Our study demonstrated a correlation between feline CKD and the absence of renal CABA, providing a feasible and alternative method for feline CKD evaluation.

A 5-year-old, clinically normal intact female Miniature Schnauzer was presented for demonstrative ultrasonography in a seminar. She had two pregnancies in the past and had a natural mating 2 months previously. Ultrasonography revealed a segmental and circumferential mural thickening of the right uterine horn. The endometrium was markedly thickened with multiple organized hyperechoic linear striations, perpendicular to the mucosal surface. Histology revealed focal endometrial hyperplasia resembling the maternal tissue of the normal canine placenta. A diagnosis of spontaneous pseudo-placentational endometrial hyperplasia (PEH) was made. This study described a unique ultrasonographic appearance of PEH, which may facilitate the diagnosis of PEH., (© 2020 National Marine Mammal Foundation. Veterinary Radiology & Ultrasound published by Wiley Periodicals, Inc. on behalf of American College of Veterinary Radiology.)

Qualitative assessment of individual cardiac chamber enlargement on thoracic radiographs was assessed using echocardiography as the gold standard in dogs. Using this method, the presence of severe left-sided cardiomegaly was hypothesized to contribute to the false identification of right-sided cardiomegaly on radiographs. 175 dogs with three-view thoracic radiographs were retrospectively included in this diagnostic accuracy study if echocardiography was done within 24 h, and no rescue therapy was provided in the interim. All radiographic studies were reviewed by two groups of five board-certified veterinary radiologists with greater and less than 10 years of experience for grading of cardiac chamber enlargement as normal or mildly, moderately, or severely enlarged. The agreement, sensitivity, and specificity of the radiologists' interpretation of cardiac chamber size on thoracic radiographs to measured echocardiographic grades were evaluated. A total of 147 cases had complete echocardiographic data available for analysis. Intragroup agreement was moderate for the evaluation of left atrial enlargement and slight to fair for all other cardiac chambers. Between the mode of the radiologists' responses in the two groups and the echocardiographic grades, there was slight agreement for all cardiac chambers with higher severity grades reported using echocardiography. When moderate to severe left-sided cardiomegaly was identified on echocardiography, the sensitivity, specificity, and accuracy of radiographs were low, identifying dogs with radiographic evidence of right-sided cardiomegaly in the absence of corresponding right-sided cardiomegaly on echocardiography. Therefore, thoracic radiographs should be used with caution for the evaluation of cardiac chamber enlargement, particularly in the presence of severe left-sided cardiomegaly., (© 2021 American College of Veterinary Radiology.)

Dissemination of glioma in humans can occur as leptomeningeal nodules, diffuse leptomeningeal lesions, or ependymal lesions. Cerebrospinal fluid (CSF) drop metastasis of glioma is not well-recognized in dogs. Ten dogs with at least two anatomically distinct and histologically confirmed foci of glioma were included in this study. The 10 dogs underwent 28 magnetic resonance imaging (MRI) examinations, with distant CSF drop metastasis revealed in 13 MRIs. The CSF drop metastases appeared as leptomeningeal nodules in four dogs, diffuse leptomeningeal lesions in six dogs, and ependymal lesions in seven dogs; six dogs had a combination of lesion types. Primary tumors were generally T2-heterogeneous and contrast-enhancing. Many metastases were T2-homogeneous and non-enhancing. Diffuse leptomeningeal lesions were seen as widespread extra-axial contrast-enhancement, again very dissimilar to the intra-axial primary mass. Primary masses were rostrotentorial, whereas metastases generally occurred in the direction of CSF flow, in ventricles, CSF cisterns, and the central canal or leptomeninges of the cervical or thoracolumbar spinal cord. Seven of the dogs had received therapy limited to the primary mass, such as surgery or stereotactic radiation, then developed metastasis in the following months. CSF drop metastasis of glioma may take a very different appearance on MRI to the primary mass, including periventricular lesions that are more homogeneous and less contrast-enhancing, rostral horn signal changes, or leptomeningeal enhancement ventral to the brainstem or encircling the spinal cord., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Bentley, Yanke, Miller, Heng, Cohen-Gadol and Rossmeisl.)

Mineral-attenuating material is occasionally seen in the anal sacs of dogs during abdominal CT studies. This retrospective, descriptive study was performed to estimate the prevalence and CT appearance of this mineral-attenuating material. A total of 357 abdominal CTs were reviewed retrospectively. The mineral-attenuating material was most easily identifiable using the brain window setting (window width: 120 HU; window level: 40 HU). In the current study, the prevalence of mineral-attenuating material in the anal sacs was 7.6% (95% confidence interval, 5.0-10.8%) with 48.1% bilateral involvement and equal distribution in the right and left in dogs with unilateral involvement. Successful collection and material analysis were performed in three dogs. The material was determined to be 100% dried blood, 100% waxy matter, and a "small amount of fat enmeshed in unidentified noncrystallined material." Given the CT appearance and the Hounsfield unit of these mineral-attenuating material within the anal sacs, the term "anal sacculiths" is proposed. All dogs with anal sacculiths within this study population did not have any reported disease of the anal sacs., (© 2020 American College of Veterinary Radiology.)

The range of cranial morphology seen in domestic dogs (Canis lupus familiaris) is a direct result of thousands of years of selective breeding. This article is the first to investigate how selection for reduced faces in brachycephalic dogs impacted the neuroanatomy of the canine brain through the analysis of endocasts. Previous research has demonstrated global effects on the shape of the bony cranium as the result of these breeding practices; however, these studies have largely focused on the bony structures of the skull and failed to consider the influence of facial reduction on the soft tissues of the brain. We generated endocasts from an existing set of clinically-obtained CT scans representing a variety of dogs with various cranial morphologies. These dogs represented four breeds as well as a comparative sample of dogs of unknown breed. We recorded three-dimensional coordinate data for 31 landmarks representing various gyri, sulci, and other neuroanatomical landmarks that allowed us to analyze differences in shape of the endocasts. Through geometric morphometric analyses, we determined that the endocast shape variance in this sample is correlated with cephalic index, and thus the selection for facial reduction has caused a perceivable effect on canine neuroanatomy. Additionally, we found the majority of the shape variance in the sample to be associated with olfactory anatomy; however, the rest of the morphology also correlates with cephalic index. The results of this article indicate that modern breeding practices and the selection for dogs with short faces have significantly influenced canine neuroanatomy., (© 2020 American Association for Anatomy.)

Objectives: The aim of this study was to compare post-mortem CT findings with necropsy findings in domestic cats., Methods: Post-mortem CT and necropsies were performed in 20 cadavers of domestic cats. The sensitivity, specificity and agreement between the post-mortem CT and necropsy findings were determined., Results: There were a total of 315 post-mortem findings; 183 were identified by post-mortem CT and 132 were identified by necropsy. Post-mortem CT demonstrated a higher sensitivity to identify the findings mainly in bones. The higher indices of agreement between post-mortem CT and necropsy were related to abnormalities of pleural space, bones and joints., Conclusions and Relevance: This study demonstrated that post-mortem CT and necropsy provided different information. Thus, their use in conjunction with each other might improve the understanding of the cause of death and the identification of post-mortem lesions.

Gallbladder pathology is common in dogs, but published studies describing the computed tomographic (CT) appearance of many gallbladder pathologies are currently lacking. This retrospective, multicenter, cases series, descriptive study evaluated the CT features of confirmed gallbladder pathology in 34 dogs. In this subset of dogs, the most common pathologies included cystic mucosal hyperplasia (15/34, 44.1%), gallbladder wall edema (9/34, 26.5%), gallbladder mucocele (8/34, 23.5%), bactibilia (7/34, 20.6%), cholecystitis (6/34, 17.6%), white bile (6/34, 17.6%), and cholelithiasis (4/34, 11.8%). The presence of intraluminal nodules, gallbladder wall thickening, hyperattenuating material (35-100 HU), and mineral attenuating material (>100 HU) were the most common abnormalities detected. However, overlap of each of these findings with a variety of gallbladder pathologies showed that none of the findings were pathognomonic for any of these pathologies. The presence of any of these CT abnormalities should increase the suspicion of gallbladder pathology and prompt further evaluation of the gallbladder for definitive diagnosis., (© 2020 American College of Veterinary Radiology.)

A 10-year-old male neutered Domestic Shorthair cat was referred for chronic inappetence, weight loss, and hematochezia and an abdominal mass. Abdominal ultrasonography revealed a heterogeneously hypoechoic transmural colonic mass, which extended beyond the serosa and into the adjacent mesentery. Cytology and clonality assays of fine needle aspirates of the mass and mesenteric nodules yielded a diagnosis of B-cell lymphoma. Colonic lymphoma with mesenteric involvement can have a similar appearance to carcinomatosis, therefore a definitive diagnosis requires sampling and further testing of the mesenteric lesions., (© 2018 American College of Veterinary Radiology.)

Intraosseous T1-weighted (T1W) and short-tau inversion recovery (STIR) magnetic resonance imaging (MRI) signal intensity changes-so-called bone marrow edema-may be able to differentiate antemortem and postmortem fractures in human forensic imaging. The primary objective of this study was to investigate this hypothesis using an animal model. Three juvenile Landrace pigs were anesthetized and underwent MRI of both tibiae and both radii using a 1.5 T magnet. T1W, T2-weighted (T2W), STIR, and T2* sequences were included. Antemortem fractures were induced in both tibiae and postmortem fractures in both radii, and MRI was repeated. Two board-certified radiologists blinded to fracture group jointly evaluated the images for intraosseous and soft tissue signal intensity changes. Sensitivity (Se) and specificity (Sp) in identifying antemortem fractures were calculated based on intraosseous, soft tissue, and combined intraosseous and soft tissue signal intensity changes. Intraosseous and soft tissue signal intensity changes, when present, were hyperintense in all sequences. Intraosseous hyperintensity in T1W and T2W sequences yielded Sp of 100% for antemortem fractures. Regardless of sequence, soft tissue hyperintensity was comparatively more sensitive than intraosseous hyperintensity. Sensitivity for each sequence could be maximized by assessment of soft tissue and intraosseous hyperintense signals together; for the T1W sequence, such assessment optimized diagnostic utility yielding a Se of 100% and Sp of 83%. In summary, MRI-particularly the T1W sequence-can differentiate antemortem and postmortem fractures and may be a useful adjunct to the forensic analyses of fractures., (© 2020 American Academy of Forensic Sciences.)

Background: Ultrasonographic features of gastric wall edema have not been reported in dogs with hypoalbuminemia., Objectives: To describe the prevalence and ultrasonographic features of gastric wall thickening in dogs with hypoalbuminemia and analyze correlation with serum albumin concentrations., Animals: Forty-two dogs with abdominal ultrasound and diagnosis of hypoalbuminemia (<2.3 g/dL)., Methods: Retrospective search in the medical records from 2018 to 2019 was performed. Ultrasound studies were reviewed and >5 mm were considered gastric wall thickening. The gastric wall changes such as thickness, layering appearance, echogenicity, echotexture, distribution of lesions, and presence of peritoneal effusion were recorded. Serial ultrasonographic examination and histopathological findings were recorded if available. Mean serum albumin concentration of dogs with and without gastric wall thickening was compared., Results: Prevalence of gastric wall thickening in dogs with hypoalbuminemia was 21.4% (95% confidence intervals 7.4-35.4%). Mean gastric wall thickness was 10.0 ± 2.0 mm. Preserved mucosal layer and thickening of submucosal layer were observed in all 9 dogs. Five dogs had 3-layer appearance in thickened submucosal layer. Diffuse wall thickening was observed in 6 dogs. All 9 dogs had peritoneal effusion. Subsequent changes of gastric wall thickening were observed in 3 dogs (range 4-70 days). Gastric wall edema was confirmed histopathologically in 2 dogs via necropsy. There was no correlation between serum albumin concentration of the dogs and gastric wall thickness., Conclusions and Clinical Importance: Findings indicated that gastric wall edema is a common finding in dogs with hypoalbuminemia. However, serum albumin concentrations did not correlate with the gastric wall thickness., (© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Through artificial selection, humans have altered the morphology of domestic dogs and created the range of morphological traits present in the diverse dog breeds seen today. This article tests how artificial breeding for extreme facial reduction affects the craniodental complex in domestic dogs (Canis lupus familiaris). These brachycephalic dog breeds allow for a natural experiment on facial reduction, providing additional insight into this well-studied phenomenon associated with the evolutionary history of other animals including primates. We used an existing set of clinically obtained CT scans from dogs representing three brachycephalic breeds and a comparative sample. We recorded three-dimensional coordinate data for 62 cranial and mandibular landmarks that allowed us to analyze differences in shape in the neurocranium, basicranium, and viscerocranium. Through geometric morphometric analysis, we confirmed that most of the cranial shape variance in our sample was associated with cephalic index (cranial width-to-length ratio) and reflects the effects of facial reduction. Shape changes in the cranium and mandible co-vary. We also identified several areas of localized shape change. Whereas the primary shape change seen in the mandible is a uniform shift in proportion involving rostral-caudal shortening and medial-lateral widening, the majority of the shape change in the palate is localized to the maxilla. Here, a pronounced difference in maxillary carnassial orientation relative to the mandibular carnassials results in disruption of the functionally important carnassial complex. These results support previous studies showing integration within the skull and highlight the deleterious effects of artificial selection for extreme facial reduction in domestic dogs. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc. Anat Rec, 303:330-346, 2020. © 2019 American Association for Anatomy., (© 2019 Wiley Periodicals, Inc.)

A 19-year-old castrated Arabian male horse presented for evaluation of a firm mass at the dorsal cervical region. Ultrasonography and computed tomography revealed multiple well defined fusiform structures within the atlantal bursa. Multiple glossy smooth, white to yellowish, flattened fusiform structures were removed surgically. These structures were composed of dense fibrin with some leukocytes and red blood cells. The imaging and histopathological features of these structures were similar to chronic 'rice bodies' reported in humans with bursitis or tenosynovitis. This is the first veterinary report describing the imaging features of 'rice bodies' in a horse with atlantal bursitis., (© 2018 American College of Veterinary Radiology.)

A 2-year-old Boer doe was presented with respiratory distress and severe inspiratory dyspnea. Cervical and thoracic radiographs revealed a marked retropharyngeal soft tissue mass effect, several mineralized pharyngeal and retropharyngeal structures, and a pulmonary mass. Computed tomography (CT) revealed a severely enlarged right medial retropharyngeal lymph node, which caused laryngeal compression, leading to upper airway obstruction. Multiple cervical and thoracic lymph nodes, and the pulmonary mass had an irregular layered/laminated pattern of mineralization. Imaging findings were consistent with caseous lymphadenitis, and further confirmed with culture, necropsy, and histopathology. This is the first report of CT appearance of caseous lymphadenitis in a goat., (© 2018 American College of Veterinary Radiology.)

Granulomas can "mimic" gliomas on magnetic resonance imaging (MRI) in human patients. The goal of this retrospective study was to report canine brain granulomas that were consistent with glioma based upon MRI, report their histologic diagnosis, and identify MRI criteria that might be useful to distinguish granuloma from glioma. Ten granulomas, initially suspected to be glioma based on MRI, were ultimately diagnosed as granulomatous meningoencephalomyelitis ( n = 5), infectious granulomas ( n = 3) or other meningoencephalitis ( n = 2). Age was 1.6-15.0 years and two dogs were brachycephalic breeds. MRI characteristics overlapping with glioma included intra-axial, heterogeneous, T2-weighted hyperintense, T1-weighted hypointense to isointense mass lesions with contrast-enhancement. Signals on fluid attenuation inversion recovery, gradient echo and diffusion weighted imaging also matched glioma. Peri-lesional edema and mass effect were toward the high end of findings reported for glioma. MRI characteristics that would be considered unusual for glioma included dural contact ( n = 4), T2-hypointensity ( n = 2), concomitant meningeal-enhancement ( n = 9), and minor changes in the contralateral brain ( n = 2). Cerebrospinal fluid analysis revealed albuminocytological dissociation or mild pleocytosis. These cases show that granulomas can "mimic" glioma on canine brain MRI. In individual cases, certain MRI findings may help increase the index of suspicion for granuloma. Lack of pronounced cerebrospinal fluid pleocytosis does not exclude granuloma. Signalment is very useful in the suspicion of glioma, and many of these dogs with granuloma were of ages and breeds in which glioma is less commonly seen.

Background: Gastric wall edema has not been reported as a complication of acute pancreatitis in dogs., Objective: To describe the ultrasonographic features of gastric wall thickening in dogs with acute pancreatitis., Animals: Fourteen dogs with ultrasonographic evidence and clinical diagnosis of acute pancreatitis, with ultrasonographic evidence of increased gastric wall thickness (>5 mm)., Methods: A retrospective search in the medical records from 2014 to 2016 was performed to identify dogs that had ultrasonographic evidence of acute pancreatitis, that had increased thickness of the gastric wall and that were diagnosed with acute pancreatitis clinically. The gastric wall changes such as thickness, layering appearance, echogenicity, distribution of lesions, and perigastric changes were recorded. Serial ultrasonographic examination and histopathological findings were recorded if available., Results: Mean gastric wall thickness was 9.9 ± 4.0 mm (SD). A complete loss of wall layering was observed in 2 dogs. Thickening of the submucosal layer was observed in 12 dogs, and 5 of them had concurrent muscularis layer thickening. The echogenicity of thickened submucosal layer was intermediate hyperechoic. Lacy appearances were present within the thickened submucosal layer in 7 dogs and in the muscularis layer of 1 dog. Thickening was focal in 12 dogs and adjacent to the diseased pancreas. Subsequent resolution of gastric wall thickening was observed in 3 dogs (range 3-28 days) via follow-up ultrasound. One dog underwent necropsy, and gastric wall edema was confirmed histopathologically., Conclusions and Clinical Importance: Findings indicated that gastric wall thickening presumably because of edema could be a complication of acute pancreatitis., (© 2019 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Purpose: The purpose was to determine the safety and antitumor activity of a folate-tubulysin conjugate (EC0531) in a relevant preclinical animal model, dogs with naturally-occurring invasive urothelial carcinoma (iUC). Canine iUC is an aggressive cancer with high folate receptor (FR) expression similar to that in certain forms of human cancer., Experimental Design: A 3+3 dose escalation study of EC0531 (starting dose 0.2 mg/kg given intravenously at two-week intervals) was performed in dogs with iUC expressing high levels of FRs (>50% positive tumor cells). Pharmacokinetic (PK) analysis was performed, and the maximum tolerated dose (MTD) was determined. The dose cohort at the MTD was expanded to determine antitumor activity., Results: The MTD of EC0531 was 0.26 mg/kg every two weeks, with grade 3-4 neutropenia and gastrointestinal toxicity observed at higher doses. Treatment at the MTD was well tolerated. Clinical benefit was found in 20 of 28 dogs (71%), including three dogs with partial remission and 17 dogs with stable disease. Plasma EC0531 concentrations in the dogs far exceeded those required to inhibit proliferation of FR-expressing cell in vitro . Unlike human neutrophils, canine neutrophils were found to express FRs, which contributes to the neutropenia at higher doses of EC0531 in dogs., Conclusion: EC0531 was well tolerated and had good antitumor activity in dogs with iUC. It is likely that humans will tolerate higher, potentially more effective doses of folate-tubulysin without myelotoxicity because of the absence of FRs on human neutrophils. The results clearly justify the evaluation of folate-tubulysin in human clinical trials., Competing Interests: CONFLICTS OF INTEREST C.P. Leamon, P.J. Klein, M.R. Pugh, S. Rao, and I. Vlahov are employees of Endocyte, Inc. Philip S. Low serves as Chief Science Officer at Endocyte, Inc. The other authors have no potential conflicts of interest.

This prospective study evaluated variation in the diameter of the caudal vena cava (DCdVC) as a marker of change in intravascular volume before and after blood donation in greyhound dogs. A preliminary study determined that the DCdVC increased with body weight. Nine greyhound blood donors had ultrasonographic images acquired of the maximum and minimum DCdVCs in transverse and sagittal orientations and sagittal aortic diameter (AoD) before and after blood donation. The collapsibility index = [(maximal mean transverse DCdVC - minimal mean transverse DCdVC)/maximal mean transverse DCdVC] and transverse DCdVC:AoD ratio were calculated for each dog. In the greyhounds, the changes in mean minimal and maximal transverse DCdVC (0.69 and 0.84 mm, respectively) and sagittal mean maximal DCdVC (0.9 mm) and collapsibility index (0.018) were significantly different ( P < 0.05) before and after blood donation. While statistically significant, the magnitude of DCdVC change found in this limited number of greyhound dogs with 8% intravascular volume loss during blood donation was small. This magnitude of change is likely indistinguishable in clinical patients.

An English Bulldog underwent radiation therapy of an intracranial, left lateral ventricle mass. Following resolution of the primary mass, an intraventricular fourth ventricle lesion developed. Subsequently, multiple lesions developed from the cervical central canal and leptomeninges. Serial magnetic resonance imaging documented the propagation of lesions along the cerebrospinal fluid (CSF) pathways, known as "CSF drop metastasis." Histopathology confirmed multifocal intraventricular and leptomeningeal oligodendroglioma. Oligodendroglioma should be included in the differential diagnosis for an intraventricular tumor exhibiting apparent CSF drop metastasis., (© 2017 American College of Veterinary Radiology.)

OBJECTIVE To compare time to achieve vascular access (TTVA) between an ultrasound-guided technique (UST) and landmark-based technique (LMT) for central venous catheter (CVC) placement in healthy anesthetized dogs. ANIMALS 39 purpose-bred hounds. PROCEDURES Anesthetized dogs that were hemodynamically stable following completion of a terminal surgical exercise were enrolled in the study during 2 phases, with a 45-day intermission between phases. For each dog, a UST and LMT were used for CVC placement via each external jugular vein by 2 operators (criticalist and resident). The TTVA and number of venipuncture attempts and catheter redirections were recorded for each catheterization. Placement of the CVC was confirmed by contrast fluoroscopy. After euthanasia, a gross dissection was performed during which a hematoma score was assigned to the catheter insertion site. For each phase, nonlinear least squares estimation was used for learning curve analysis of the UST. RESULTS Median TTVA, number of venipuncture attempts and catheter redirections, and hematoma score did not differ significantly between the 2 operators for either technique. Median TTVA for the UST (45 seconds) was significantly longer than that for the LMT (7 seconds). Learning curve analysis indicated that 8 and 7 UST catheterizations were required to achieve performance stability in phases 1 and 2, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the UST was comparable to the LMT for CVC placement in healthy dogs. The extra time required to perform the UST was not clinically relevant. Additional studies evaluating the UST for CVC placement in clinically ill dogs are warranted.

In radiation therapy (RT) treatment planning for canine head and neck cancer, the tonsils may be included as part of the treated volume. Delineation of tonsils on computed tomography (CT) scans is difficult. Error or uncertainty in the volume and location of contoured structures may result in treatment failure. The purpose of this prospective, observer agreement study was to assess the interobserver agreement of tonsillar contouring by two groups of trained observers. Thirty dogs undergoing pre- and post-contrast CT studies of the head were included. After the pre- and postcontrast CT scans, the tonsils were identified via direct visualization, barium paste was applied bilaterally to the visible tonsils, and a third CT scan was acquired. Data from each of the three CT scans were registered in an RT treatment planning system. Two groups of observers (one veterinary radiologist and one veterinary radiation oncologist in each group) contoured bilateral tonsils by consensus, obtaining three sets of contours. Tonsil volume and location data were obtained from both groups. The contour volumes and locations were compared between groups using mixed (fixed and random effect) linear models. There was no significant difference between each group's contours in terms of three-dimensional coordinates. However there was a significant difference between each group's contours in terms of the tonsillar volume (P < 0.0001). Pre- and postcontrast CT can be used to identify the location of canine tonsils with reasonable agreement between trained observers. Discrepancy in tonsillar volume between groups of trained observers may affect RT treatment outcome., (© 2017 American College of Veterinary Radiology.)

Image quality in B-mode ultrasound is important as it reflects the diagnostic accuracy and diagnostic information provided during clinical scanning. Quality assurance programs for B-mode ultrasound systems/components are comprised of initial quality acceptance testing and subsequent regularly scheduled quality control testing. The importance of quality assurance programs for B-mode ultrasound image quality using ultrasound phantoms is well documented in the human medical and medical physics literature. The purpose of this prospective, cross-sectional, survey study was to determine the prevalence and methodology of quality acceptance testing and quality control testing of image quality for ultrasound system/components among veterinary sonographers. An online electronic survey was sent to 1497 members of veterinary imaging organizations: the American College of Veterinary Radiology, the Veterinary Ultrasound Society, and the European Association of Veterinary Diagnostic Imaging, and a total of 167 responses were received. The results showed that the percentages of veterinary sonographers performing quality acceptance testing and quality control testing are 42% (64/151; 95% confidence interval 34-52%) and 26% (40/156: 95% confidence interval 19-33%) respectively. Of the respondents who claimed to have quality acceptance testing or quality control testing of image quality in place for their ultrasound system/components, 0% have performed quality acceptance testing or quality control testing correctly (quality acceptance testing 95% confidence interval: 0-6%, quality control testing 95% confidence interval: 0-11%). Further education and guidelines are recommended for veterinary sonographers in the area of quality acceptance testing and quality control testing for B-mode ultrasound equipment/components., (© 2018 American College of Veterinary Radiology.)

OBJECTIVE To determine the optimal protocol for acquisition of CT images of the dentition in alpacas. ANIMALS 3 healthy adult male alpacas. PROCEDURES Each alpaca was anesthetized with an IM injection of a combination of ketamine, xylazine, and butorphanol and positioned in sternal recumbency on the CT couch with its legs folded in a natural cush position and its head positioned within the isocenter of the gantry of a 64-slice CT scanner. Images were acquired by means of 6 protocols (sequential and helical modes at slice thicknesses of 1.25, 2.5, and 5 mm). Five images (2 molar, 2 premolar, and mandibular incisor teeth) were selected from each protocol for evaluation by 3 veterinary radiologists. For each image, tooth root visibility and sharpness and image noise artifact were subjectively evaluated on a 3-point scoring system. RESULTS Slice thickness significantly affected tooth root visibility and tooth root sharpness but did not affect image noise artifact. Acquisition mode significantly affected tooth root visibility and tooth root sharpness as well as image noise artifact. Tooth root visibility and sharpness did not differ significantly between the helical and sequential images when the slice thickness was 1.25 mm. Image noise artifact was greater for helical images than sequential images but did not differ by slice thickness within either acquisition mode. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that for a 64-slice CT scanner, the optimal protocol for the acquisition of CT images of the dentition in alpacas was a sequential scan with a slice thickness of 1.25 mm.

Background: Ultrasonographic appearance of unorganized hyperechoic striations (UHS) has been observed in the canine gastric muscularis layer. The purpose of the study was to determine the prevalence, sonographic and postmortem histologic features, and to determine the clinical significance of canine gastric muscularis UHS. In the prospective study, 72 dogs were included. The presence of gastric muscularis UHS were reviewed to determine its distribution and location. In the retrospective study, 167 dogs that had both abdominal ultrasonography and necropsy were included., Results: The prevalence of gastric muscularis UHS in dogs was 37.5% in the prospective and 5.4% in the retrospective studies respectively. The higher prevalence in prospective study was due to greater anticipation by the radiologists in search for gastric muscularis UHS. In the ventral gastric wall, the muscularis UHS were better defined when the gastric lumen was empty or non-distended, and were mostly parallel with the serosa when the gastric wall was distended (with gas or fluid). Visualization of the dorsal gastric wall was often obscured by gas shadowing from luminal gas. Histopathology was performed on eight dogs with gastric muscularis UHS, three of which had fibrous tissue observed with Masson's trichrome stain., Conclusion: Presence of gastric muscularis UHS in dogs may have been attributable to presence of incomplete interfaces between the inner oblique, middle circular and outer longitudinal layers of the gastric tunica muscularis or due to presence of fibrous tissue within the gastric muscularis layer. The clinical significance of canine gastric muscularis UHS is uncertain.

A firm mass was noted in the right inguinal subcutaneous region of an 11-year-old intact male Labrador retriever dog presented for right pelvic limb weakness. Pelvic radiographs showed 2 large ovoid structures with circumferential thin eggshell-like mineralization in the right external inguinal region. The structures were confirmed sonographically, and on magnetic resonance imaging as a large folded herniated mineralized paraprostatic cyst through a defect in the right inguinal wall. To the author's knowledge, this is the first published report of an inguinal herniated mineralized paraprostatic cyst.

Background: Osteochondritis dissecans (OCD) is a sequela to osteochondrosis, whereby the cartilage superficial to the site of osteochondrosis fractures and gives rise to osteochondral fragments in the affected joint. In this case, both the radiological and computed tomography findings were supportive of classical severe OCD but the histologic findings were not supportive of the diagnosis of OCD., Case Presentation: A 1 year and 6 months old, Saddlebred, colt was presented for evaluation of chronic cervical pain. Standing laterolateral radiographs revealed an osteochondral fragment with corresponding irregular subchondral bone defect at one of the occipital condyle. Computed tomography confirmed the presence of osteochondral fragments at the left occipital condyle and several articular process joints of the cervical spine, with associated subchondral bone defects and sclerosis, suggestive of OCD. However, the lack of ischemic chondronecrosis microscopically was not supportive of a histologic diagnosis of OCD. Therefore, the term 'OCD-like lesions' was deemed most appropriate for these cervical lesions., Conclusion: In the event where imaging features were characteristics of OCD but lack of histologic evidence of ischemic chondronecrosis, the term 'OCD-like lesion' is deemed most appropriate.

Insulinoma is a functional, insulin-secreting tumor, arising from the beta islet cells of the pancreas. It is one of the most common neoplasms in ferrets and has been associated with clinical signs of hypoglycemia, such as ptyalism, pawing at the mouth, seizures, lethargy, and coma. The ultrasonographic features of insulinoma in ferrets have not been previously reported. The purpose of this retrospective case series study was to describe the ultrasonographic features of confirmed insulinoma in a group of ferrets. Inclusion criteria were abdominal ultrasound examination and histological confirmed insulinoma by surgical biopsy. Six ferrets met the inclusion criteria, all of which had multiple hypoglycemic episodes. Ultrasonographic images were reviewed and the characteristics of the pancreatic nodules were recorded. Twenty-eight pancreatic nodules were observed in the six ferrets and were primarily hypoechoic (89.3%, 25/28) and homogenous (46.4%, 13/28) with a smooth margin (78.6%, 22/28). The distribution of the pancreatic nodules was 46.4% in the left lobe, 50% in the right lobe, and 3.6% in the body of the pancreas. The sizes of the pancreatic nodules varied from 1.5 × 1.5 to 4.1 × 5.6 mm. All of the pancreatic nodules removed from surgery were histopathologically confirmed as insulinoma. The findings indicated that insulinoma in ferrets could be detected through ultrasonography, which may facilitate diagnosis and preoperative surgical planning., (© 2017 American College of Veterinary Radiology.)

Imaging studies are often of evidentiary value in medicolegal investigations involving animals and the role of the veterinary radiologist is to interpret those images for courts as an expert or opinion witness. With progressing interest in prosecuting animal crimes and strengthening of penalties for crimes against animals, the participation of veterinary radiologists in medicolegal investigations is expected to increase. Veterinary radiologists who are aware of radiographic and imaging signs that result in animal suffering, abuse, or neglect; knowledgeable in ways radiology and imaging may support cause of death determinations; conversant in postmortem imaging; comfortable discussing mechanisms and timing of blunt or sharp force and projectile trauma in imaging; and prepared to identify mimics of abuse can assist court participants in understanding imaging evidence. The goal of this commentary review is to familiarize veterinary radiologists with the forensic radiology and imaging literature and with the advantages and disadvantages of various imaging modalities utilized in forensic investigations. Another goal is to provide background information for future research studies in veterinary forensic radiology and imaging., (© 2017 American College of Veterinary Radiology.)