Veterinary Radiology & Ultrasound最新文献

When heart disease progresses to heart failure, congestion develops in various organs, including the liver and kidneys. Although organ congestion is a critical factor closely associated with the prognosis of heart failure, a simple and quantitative method for evaluating the degree of organ congestion has not yet been established. Two-dimensional shear wave elastography (2D-SWE) is a noninvasive ultrasound technique that can estimate tissue stiffness by measuring shear wave speed (SWS), an index of tissue viscoelasticity, and dispersion slope (DS), which reflects tissue viscosity alone. This study aimed to assess the utility of SWS and DS in evaluating hepatic and renal congestion in transfused dogs by performing 2D-SWE before and after blood transfusion. The ratio of the short diameter (SD) to the long diameter (LD) of the caudal vena cava (CVC SD/LD) was used as an index of congestion. Twenty transfusions were administered to 17 dogs. After transfusion, both the liver and kidney SWS and DS, along with CVC SD/LD, significantly increased. A moderate positive correlation was observed between the CVC SD/LD and liver SWS (r = 0.781, p < 0.01) and kidney SWS (r = 0.744, p < 0.01). Conversely, a strong positive correlation was found between the CVC SD/LD and liver DS (r = 0.900, p < 0.01) and kidney DS (r = 0.850, p < 0.01). These findings suggest that 2D-SWE may be a valuable tool for assessing liver and kidney congestion, with DS potentially serving as a reliable indicator of congestion.

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

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

Transarterial chemoembolization (TACE) has recently emerged as a new alternative and palliative treatment option for head and neck cancers in human medicine, with a few case reports in veterinary medicine also showing good outcomes for canine oronasal tumors. Therefore, this study aimed to analyze the anatomical structures of canine head arteries using computed tomography angiography (CTA), focusing on the feeding arteries of oronasal tumors, as this information is essential for interventional procedures. This retrospective multicenter study used triple-phase CTA images of nasal tumors (n = 30), oral tumors (n = 31) (including one case of a caudal mandibular tumor with two tumors), and a control group (n = 51). Among the 100 feeding arteries identified in the 61 oronasal tumors, the descending palatine artery (27/45; 60%) had the highest prevalence in nasal tumors. In rostral maxillary tumors, the infraorbital artery (10/24; 41.7%) was identified as the major feeding artery, whereas in mandibular tumors, the facial artery was the most prevalent feeder in both the rostral (4/4; 100%) and caudal (6/7; 85.7%) locations. Of the 222 head arteries observed on CTA, all lingual and facial arteries originated separately. The mean diameters of the major head arteries in different groups were significantly and positively correlated with body weight. However, when comparing the diameters of the head arteries normalized to body weight between the tumor feeder group and the control group, no significant difference was observed. This study provided comprehensive information on canine head arteries, including the feeding arteries of oronasal tumors, which is important for preprocedural planning.

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

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

A 6-year-old male neutered Jack Russell Terrier presented via the emergency department for subacute progressive asymmetrical tetraparesis and cervical hyperesthesia. MRI showed T2-weighted (T2W) and T1-weighted (T1W) hypointense material, positioned dorsocaudally to the C3-4 intervertebral disc on the right ventrolateral aspect of the spinal cord, causing moderate-to-severe compression of the spinal cord. The material was sharply marginated with a pointed/sharp beak-like appearance (beak sign). On parasagittal images, two hyperintense lines appearing as a "Y" were appreciated (Y-sign). Surgical findings confirmed an intradural/extramedullary intervertebral disc extrusion (IVDE). This is the first report of a cervical intradural/extramedullary IVDE in a dog.

As alpacas (Vicugna pacos) gain popularity globally, the need for improved knowledge about the species grows, including a better understanding of dental pathologies increasingly recognized in domesticated populations. Oral examination and radiology are commonly used tools for the detection of periapical infections and other dental diseases. In this diagnostic accuracy study, we aim to calculate the sensitivity and specificity of these two modalities to determine their agreement with histology in the detection of periodontal (periapical and periradicular) and pulpal pathologies. Seven alpacas were included in the study and underwent oral examination and radiography. After euthanasia, 18 teeth were harvested for histological evaluation. Sensitivity and specificity of radiography in detecting periapical infections were 100% and 85%, respectively, compared to a sensitivity of 54% and a specificity of 75% for clinical evaluation. The level of agreement between these two modalities for the detection of periapical disease was weak (22%). Sensitivity and specificity of radiography in diagnosing periapical periodontal changes were 100% and 83%, compared to clinical evaluation, which had a sensitivity of 100% and a specificity of 36%. The sensitivity of radiology in detecting pulpar changes was low (8%), while it was high (77%) for clinical examination. These findings demonstrate that radiography is a meaningful supplement for confirming suspected clinical diagnoses of periodontal and periapical changes in alpacas.

Little information concerning the CT characteristics of the canine brachial plexus is available. This study aimed to describe size measurements and CT characteristics of the brachial plexus in dogs and explore correlations with patient characteristics to provide clinical interpretation guidelines. A retrospective analysis of 39 thoracic CT studies categorized dogs by weight and breed type (chondrodystrophic/non-chondrodystrophic). The brachial plexus was evaluated at a defined anatomical location in the axillary region, with measurements recorded for size (cross-sectional area, height, and width), attenuation (HU), subjective conspicuity, and the amount of interlying fat tissue. A strong positive correlation was found between dog weight and all brachial plexus size measurements (p < 0.0001). Intra- and interrater reliability of size measurements was moderate to excellent (ICC 0.74-0.92 and 0.77-0.99, respectively), but those with the highest reliability lacked absolute consistency (large standard error of measurement). Age was negatively correlated with size, but this association was confounded by weight. Neither laterality, sex, nor breed type significantly affected size or attenuation. The subjectively estimated amount of interlying fat was significantly associated with minimum precontrast attenuation values and the conspicuity of the brachial plexus, with dogs having more fat showing a blurred plexus appearance. No difference was found for the characteristics of the brachial plexus when evaluating chondrodystrophic breed-type dogs compared to non-chondrodystrophic ones. These descriptive characteristics, stratified by weight, provide valuable guidelines for clinical interpretation of the presumed normal canine brachial plexus on CT.

A sonographic reticulonodular splenic pattern is characterized by numerous hypoechoic nodules throughout the parenchyma and is commonly associated with benign, neoplastic, or infectious etiologies. However, this has been described as a normal age-related variant in children and puppies up to 1 year old. The purpose of this study was to determine whether the ultrasonographic appearance of the spleens of healthy kittens mimics that of normal puppies. This was a prospective, descriptive study design. Sixty-seven spleens and 50 healthy kittens (13 repeat kittens) were included. Apparently healthy kittens between the ages of 0 months and 1.5 years were scanned using a high-frequency linear transducer. Ultrasonographic patterns of the spleen were graded as follows: grade 1, homogeneous echotexture; grade 2, faint nodules <10% of the parenchyma; grade 3, larger ill-defined nodules involving 10%-25% of the spleen; and grade 4, large well-defined nodules involving >25% of the spleen. A reticulonodular pattern was present in 62 spleens (92%), with grade 2 most common. The grades were highest on average between 0 and 4 months old. Unexpectedly, young cats up to at least 1.5 years old were often noted to have a reticulonodular pattern. After 4 months old, there was a negative association with age and the grade of the spleen. This overall negative association persisted even among kittens that were enrolled serially. The findings of this study suggest that a reticulonodular pattern in young cats and kittens may be a normal finding and should not be mistaken for pathology.