Veterinary Radiology & Ultrasound最新文献

Ring-enhancing magnetic resonance imaging (MRI) lesions result from various diseases, including infection, neoplasia, inflammation, and vascular etiologies. Differentiation based on standard MRI sequences can be challenging. This study aims to compare the apparent diffusion coefficient (ADC) values of intracranial ring-enhancing lesions of infectious etiology with ring-enhancing lesions caused by other etiologies. Records were reviewed for MRI studies with diffusion-weighted imaging (DWI) and post-gadolinium T1-weighted ring-enhancing lesions with a definitive histopathological diagnosis or a microbiological diagnosis of brain infection. ADC maps were generated, and regions of interest were selected to evaluate ADC values of ring-enhancing lesions. Normalized ADC values (rADC) were calculated using ADC values from lesional and contralateral brain regions of interest (rADC = ADC_lesion/ADC_CB). A total of 69 cases met the inclusion criteria (68 dogs, 1 cat). Median (range) rADC was significantly lower for intraparenchymal bacterial abscesses [0.54 (0.19-0.82)] compared to ring-enhancing gliomas [1.7 (0.80-3.9); p = 0.0003) and non-infectious inflammatory lesions [1.7 (0.74-3.3); p = 0.024], but not significantly different compared to intraparenchymal hemorrhage [0.54 (0.33-0.87); p > 0.99]. Extraparenchymal bacterial empyema and intraparenchymal fungal abscesses did not exhibit apparent restricted diffusion, with median rADC (range) of 2.8 (1.3-3.4) and 1.2 (1.1-1.8), respectively. With exclusion of hemorrhagic lesions, an rADC of 0.65 had a specificity/sensitivity of 98%/78% for intraparenchymal bacterial abscess. Apparent restricted diffusion on DWI and ADC is a useful marker for identifying intraparenchymal bacterial abscesses among ring-enhancing lesions. However, extraparenchymal bacterial empyema and fungal abscesses may not exhibit this feature.

A 12-year-old male neutered miniature Schnauzer underwent computed tomography of the head for evaluation of a sublingual mass. The dog had prior bilateral pars plana vitrectomies with silicone oil tamponade and endolaser retinopexy for treatment of retinal detachment. On evaluation of the computed tomographic images, the vitreous chambers contained a large volume of smoothly marginated hyperattenuating material with a mass-like appearance, consistent with silicone oil. The imaging characteristics of silicone oil on computed tomography can be a source of diagnostic confusion, underscoring the importance of recognizing these features in dogs that may undergo computed tomography for other indications.

Diaphragmatic tumors are uncommon in veterinary medicine. A 9-year-old neutered male Chihuahua was referred for evaluation of a suspected diaphragmatic hernia. Computed tomography revealed a soft tissue mass with a continuous border to the adjacent diaphragm, compressing the liver caudally. The tumor exhibited hypoattenuating lesions suspected of a mixture of fat and soft tissue. Histopathologic examination diagnosed a well-differentiated liposarcoma. A mass exhibiting a continuous border with the diaphragm and displacement of the adjacent liver may indicate a diaphragmatic tumor. Attenuation indicating a mixture of fat and soft tissue may be a feature of well-differentiated liposarcoma, but further studies on liposarcoma subtypes are needed.

The preoperative detection of abdominal adhesions could influence surgical planning; however, imaging features of abdominal adhesions are minimally described in the veterinary literature. The purpose of this retrospective, diagnostic case-control study is to determine the preoperative CT imaging signs associated with surgically-confirmed, severe adhesions in dogs with abdominal masses. Dogs undergoing contrast-enhanced CT and surgery for abdominal masses from 2012 to 2022 were included in the study. Surgical records were evaluated and retrospectively reviewed by a board-certified surgeon to determine the severity of adhesions as pertaining to surgical planning and/or complications. The CTs of dogs with severe adhesions were mixed with age and weight-matched controls for review by a board-certified veterinary radiologist. A review of the literature on both people and animals determined the imaging features tested. The signs tested were fat stranding, fat stranding with vascular enhancement or vascular crowding, loss of fat planes (properitoneal fat sign), focal peritoneal enhancement with or without an alteration in visceral contour, loculation of fluid, and enhancing peritoneal bands. The presence of fat stranding (sensitivity 60.5; specificity 72.1), fat stranding with vascular enhancement (sensitivity 53.5, specificity 81.4), and loculation of peritoneal effusion (sensitivity 25.5; specificity 95.3) were significantly associated with the presence of adhesions at surgery. Loculation of peritoneal effusion surrounding the nondependent margin of an abdominal mass can alert imagers to the presence of severe adhesions. The absence of any of the signs tested does not exclude the presence of adhesions, especially in the retroperitoneum.

This study aimed to identify triple-phase computed tomographic features that can predict the histotype of focal liver lesions in dogs. The analysis included dogs with histopathologically diagnosed nodular hyperplasia (NH, n = 3), hepatocellular adenoma (HCA, n = 32), or hepatocellular carcinoma (HCC, n = 59). Consistent with previous studies (Kutara et al. 2014; Burti et al. 2021), significant differences were observed in maximum transverse diameter (p = .008) and enhancement patterns (p = .0031) among the lesion types. HCCs were significantly larger and exhibited heterogeneous enhancement compared with benign lesions. In the portal venous phase, benign lesions were significantly hyperattenuating (p < .001) with a mean HU of 175.3 (±38.8), while HCCs were significantly hypoattenuating (p < .001) with a mean HU of 123.9 (±28.8), relative to the surrounding liver parenchyma (mean HU 151.6 ± 17.7). In the delayed phase, benign lesions became isoattenuating (mean HU 117.2 ± 10.7) to the liver parenchyma (mean HU 122.6 ± 8.4), whereas HCCs remained hypoattenuating (mean HU 100.3 ± 12.7). A maximal transverse diameter greater than 9.8 cm (AUC = 0.73), a heterogeneous enhancement pattern in all three phases (AUC = 0.7), and a portal venous phase HU below 136 (AUC = 0.87) were significantly associated with HCC, achieving an accuracy of 89% and a positive predictive value of 91%. The study suggests that lesion HU in the portal venous phase, alongside lesion size and enhancement pattern, are strong predictors of HCC in dogs, with specific cutoff values serving as reliable indicators.

Pulmonary emphysema (PE) is a poorly understood condition in rabbits. This retrospective case-control study investigated the CT and clinical findings of rabbits with PE. Institutional archive review identified 724 thoracic CT studies of 529 rabbits, including 76 PE-positive studies of 59/529 rabbits. Twenty-five PE-negative cases were selected randomly as a control group. The mean age of affected rabbits was 9 years (range 5-13 years). Cranial lung lobes were more commonly affected (p < .01). The X-ray attenuation in Hounsfield units (HU) of the emphysematous lung areas (median -905 HU) was significantly lower than in nonemphysematous lung lobes of the case (median -667 HU) and control group (median -652 HU). There was significantly lower X-ray attenuation in peripheral and bullous emphysema than in diffuse emphysema. There was no statistical correlation between clinical lower respiratory signs and PE presence. However, the small portion (n = 6, 10.2%) of affected rabbits with severe respiratory signs, such as open-mouth breathing and cyanotic mucous membranes, all had advanced PE and poor outcome. Secondary changes attributable to PE included pathologic rib fractures in 3 (5.1%) and bulla rupture leading to pneumothorax in 2 (3.4%) rabbits. Of the 15 rabbits with repeat examinations, PE was progressive in 12 (80%) and static in 3 (20%). PE is a common condition in rabbits that is readily detectable with CT. The progressive nature of PE should be considered when detected in asymptomatic rabbits. In rabbits with severe lower respiratory signs, PE should be considered as a potential cause.

In veterinary medicine, deferent ducts are described as being visible on ultrasound only when pathologically enlarged. Abnormal ultrasonographic enlargement of the deferent ducts has primarily been described secondary to infectious and neoplastic diseases; however, no studies have evaluated the normal ultrasonographic features of these structures. This prospective observational study aimed to describe the ultrasonographic appearance of deferent ducts and assess ultrasound reliability in their identification in intact and neutered dogs without genitourinary disease. The study aimed also to compare ultrasonographic measurements with postmortem anatomical ones and to investigate the relationship between duct identification, size, and intrinsic factors of the patient. The study consisted of ex vivo and in vivo phases in which ultrasonographic assessments of the ducts were conducted at the level of the prostate in longitudinal (location 1) and transverse (location 2) planes and the inguinal canal (location 3) and scrotal region (location 4) in longitudinal planes. A total of 80 deferent ducts were included. The ducts were visible as paired tubular hypoechoic structures delimited by two thin hyperechoic lines, with a target-like appearance on the transverse plane. The deferent ducts were identified in 97.5% of our population in at least one location, with locations 1 and 2 being the most reliable ones. Identification of the ducts was independent of reproductive status; however, reproductive status appeared to be the most significant factor influencing deferent duct size, with neutered dogs exhibiting smaller deferent ducts.

There is limited published information on the os clitoridis in veterinary species. This retrospective study aims to provide information on its prevalence and radiographic appearance in client-owned female domesticated ferrets (Mustela putorius furo) presented to an academic veterinary medical center, and investigate any association with age, intact versus spayed status, and adrenal disease. Sixty-six ferrets (37 intact and 29 spayed) with a median age of 39.5 months (range, 2-118 months) met inclusion criteria. An os clitoridis was identified in 49 of 66 animals (74.24%). The mean length was 3.06 ± 1.20 mm and the mean width 0.68 ± 0.18 mm. An os clitoritis was significantly more common in intact (p = .0229) and in older animals (p = .01454). There was no association between an os clitoridis and adrenal disease (p = .2188). The os clitoridis is a normal anatomic structure on radiographs of female ferrets and should not be misinterpreted as an abnormality.

United airway disease (UAD) expresses an association between inflammatory upper and lower airway disease in humans but has not been reported in clinically affected feline patients. The purpose of this retrospective case series study is to determine the prevalence of CT changes consistent with feline lower airway disease (FLAD; feline asthma/chronic bronchitis) in cats with inflammatory upper airway disease including otitis media. Included were 549 cats with clinical complaints of inflammatory upper airway disease and/or otitis media and CT examinations of the head, neck, and thorax. CT examinations were reviewed for changes consistent with inflammatory upper airway disease (rhinitis, nasopharyngitis, otitis media) and FLAD. Odds ratios for FLAD were calculated for cats with rhinitis, nasopharyngitis, or otitis media and cats with a combination of rhinitis and otitis media. Rhinitis was diagnosed in 348 cats, nasopharyngitis in 253 cats, otitis media in 287 cats, and FLAD in 338 cats. The odds ratio for the concurrent presence of FLAD in cats with rhinitis, nasopharyngitis, or otitis media were 1.62, 1.46, and 1.46, respectively. The odds ratio for FLAD for cats with a combination of rhinitis and otitis media was 2.27. Otitis media was found to be an independent risk factor for FLAD. CT evidence of FLAD is common in cats with inflammatory upper airway disease, and especially in cats with a combination of rhinitis and otitis media. These findings strongly suggest the presence of United Airway Disease in cats.