Veterinary Radiology & Ultrasound最新文献

Elastography is a promising technique for assessing tissue stiffness in the adrenal glands of dogs with hypercortisolism (HC). This study compared 30 dogs, 15 of which were healthy (control group) and 15 diagnosed with HC, confirmed by low-dose dexamethasone suppression test (n = 11) or ACTH stimulation test (n = 4) without prior treatment. Ultrasound measurements revealed a significant increase in the dimensions of the adrenal glands, especially in the left adrenal gland, with more frequent changes in the cranial pole (86.7%, p = 0.00003) and caudal pole (80%, p = 0.00005). Qualitative elastography indicated varied tissue stiffness patterns in sick dogs, with a predominance of mixed patterns (46.7%), whereas dogs in the control group showed uniform moderate stiffness. Semiquantitative analysis showed that the adrenal glands of sick dogs were significantly stiffer compared to the adjacent mesentery, with variations ranging from 33% to 80% stiffer. The Mann-Whitney test revealed statistically significant differences in adrenal stiffness between the groups (U = 4.500; Z = -4.621; p < 0.001). These findings suggest that elastography, combined with conventional ultrasonography, may be an effective complementary diagnostic tool in detecting adrenal changes in dogs with HC.

A 5-year-old Siamese cat presented with acute regurgitation and vomiting. Multimodal imaging revealed a tortuous thoracic aorta causing extraluminal esophageal compression. This vascular anomaly shares features with a rare human syndrome known as dysphagia aortica. The absence of hypertensive cardiomyopathy suggested a congenital malformation, despite the delayed presentation. Endoscopy confirmed esophageal stenosis with ulcerative lesions secondary to a trichobezoar obstruction at the stenotic site. Conservative management led to clinical improvement. This report documents, to our knowledge, the first feline case of presumed dysphagia aortica of likely congenital origin, expanding the spectrum of vascular causes for esophageal obstruction.

The lungs are a common site of metastasis, with recognized computed tomography (CT) features of different histotypes in humans. Little information is available for dogs. This retrospective, observational study compared the CT characteristics of pulmonary metastases from different primary cancers in dogs. CT studies of two groups of dogs with primary neoplasia and pulmonary metastases were reviewed. Group 1 (n = 271) included dogs with a definitive diagnosis of either the primary neoplasia, the metastases, or both, and Group 2 (n = 126) was a subgroup with both diagnoses confirmed. Six primary tumor histotypes were analyzed: epithelial cancer, bone sarcoma, soft tissue sarcoma, melanoma, hemangiosarcoma (HSA), and histiocytic sarcoma. Recorded features included nodule number, distribution, shape, size, margins, attenuation, pattern of enhancement, and the presence of other abnormalities. For both groups, CT features statistically correlated with tumor histotype (p < 0.0001) included ill-defined margins and cavitary lesions in carcinomas; bronchial thickening and pleural effusion in pulmonary carcinomas; a higher number of nodules, spotty postcontrast linear to amorphous strong hyperdensity (SPLASH) sign, halo sign, and extrapulmonary metastases in HSAs; and larger nodule size (>1 cm), air bronchograms, and thoracic lymphadenomegaly in histiocytic sarcomas and incomplete nodule mineralization in bone sarcomas. CT features of lung metastases help prioritize neoplasia histotype in dogs, aiding diagnosis if the primary tumor is not obvious, if two cancers are potential origins of the metastases, or when the pulmonary nodules cannot be sampled.

Otitis externa (OE) is a common condition in dogs. Otoscopic examination is the standard diagnostic procedure, but not all external ear canal structures can be assessed otoscopically. Computed tomography (CT) has become a gold standard in the assessment of middle ear disease. This study aimed to assess the validity of CT for canine OE and to compare CT-specific and otoscopy-specific findings that are consistent with OE. CT studies of dogs referred for suspected OE were blindly reviewed by three observers for ear canal wall mineralization, thickness, and contrast enhancement. Otoscopic findings were used as the reference standard. The sensitivity and specificity of CT for the diagnosis of OE were 98.2% (95% confidence interval [CI]: 90.4%-99.7%) and 60.0% (95% CI: 10.7%-76.6%), respectively. The positive predictive value (PPV) was 84.4%, and there was substantial agreement (weighted κ = 0.65) between CT and otoscopic diagnosis of OE. There was moderate agreement (weighted κ = 0.47) between the presence of CT ear canal wall contrast enhancement and the degree of erythema otoscopically, and moderate agreement (weighted κ = 0.58), comparing the consensus CT grade for ear canal wall thickness to the grade of ear canal stenosis on otoscopic examination. The presence of external ear canal wall mineralization on CT was independent of disease (p = 0.49) and disease duration (p = 0.26), indicating mineralization of the external ear canal wall on CT is not necessarily related to chronic OE. There is substantial agreement between CT and otoscopy, supporting its use as a diagnostic technique for OE.

Spinal dural ossifications (SDOs) are bone plaques on the dura mater surface. They are usually incidental findings in humans and dogs, and rarely can cause clinical signs. The authors noticed that SDOs on magnetic resonance imaging (MRI) may appear hyperintense on a pre-contrast T1-weighted (T1W) sequence. This study aimed to assess the MRI signal of SDOs in dogs. For this retrospective descriptive study, the hospital archive was searched for dogs that underwent both a pre-contrast computed tomography (CT) study and at least one pre-contrast T1W MRI sequence, from January 2020 to April 2024. CT images were evaluated for the presence of SDOs, and the MRI signal of the lesions was assessed at the same level by one first-year diagnostic imaging resident and three board-certified radiologists. Dogs' breed, gender, and age were recorded. Ten dogs were included. Adult dogs (median = 10.5 years) and large breed dogs (median = 31 kg) were overrepresented. On CT, all SDOs appeared as punctiform or linear mineral-attenuating structures on the dura mater. SDOs were predominantly hyperintense on T1W and hypointense on T2-weighted (T2W) images. When fluid attenuating inversion recovery (FLAIR), short tau inversion recovery (STIR), and T2*W sequences were available, SDOs were hyperintense, iso-/hypointense, and presented signal void, respectively. This study confirms SDOs are commonly T1 hyperintense. This signal likely depends on the architecture of microcalcifications: calcium traps water protons, slowing their rotation to near Larmor frequency, and shortening T1 recovery times. Pre-contrast T1W sequences should be carefully evaluated to avoid misinterpreting SDOs for contrast-enhancing dural pathologies (such as plaque-like neoplastic dural lesions) or punctiform hemorrhage.

A 7-year-old female intact, black-and-white ruffed lemur (Varecia variegata) presented for acute anorexia, lethargy, and abnormal behavior. Initial radiographs were concerning for gastrointestinal ileus. Abdominal ultrasonography identified bilateral periovarian masses and a moderate volume of echogenic peritoneal effusion; no definitive blood flow was seen within the masses on Color Doppler. Bilateral ovariectomy was performed, and histopathology confirmed bilateral ovarian hematomata and hemoabdomen due to an idiopathic arteriopathy. The patient recovered with no significant postoperative complications. This is the first reported case of spontaneous bilateral ovarian hemorrhage in a black-and-white ruffed lemur, secondary to idiopathic arteriopathy, reported within the veterinary literature.

An 11-year-old female Shih Tzu exhibited dysuria after removal of a large vaginal mass. Abdominal ultrasound revealed bilateral hydronephrosis, hydroureter, and urinary bladder (UB) dilation. The urethral opening was located ventral to the UB, cranial to its normal position. The right ureterovesical junction (UVJ) opened on the ventral aspect of the UB, left of the urethral opening; the left ureter coursed abruptly ventrally at the UB level. Retrograde urethrography confirmed the abnormal position of the urethral opening. Computed tomography demonstrated abnormal positioning of the urethral opening and bilateral UVJs, along with distal ureter rotation. Surgical findings confirmed UB torsion.

A 3-year-old intact female Sulawesi crested macaque (Macaca nigra) was referred for progressive abnormal behavior and ataxia in all four limbs. Computed tomography (CT) and magnetic resonance imaging revealed cystic lesions located in the occipital lobes and in the right cerebellar culmen, together with the presence of communication between the subarachnoid space and lateral ventricles. The lesions showed no contrast enhancement on CT. These imaging findings were consistent with porencephaly, which was confirmed on necropsy and histopathology. An inflammatory meningoencephalitis was diagnosed.

Gastric dilatation-volvulus (GDV) was diagnosed in four adult guinea pigs with histories of lethargy and progressive hyporexia. Clinical examination varied between cases and was not specific for gastrointestinal disease. CT revealed a severely gas-dilated and malpositioned stomach in all cases. In three guinea pigs, a "whirl sign" was centered around the esophagus. Whole body CT facilitated the detection of significant concurrent pathology such as a splenic mass, obstructive ureterolithiasis, and aspiration pneumonia, leading to euthanasia in two cases. One guinea pig was successfully managed with orogastric tubing. One guinea pig had chronic signs of abdominal disease, which is rarely documented in cases of GDV. Whilst abdominal radiographs are often considered diagnostic for GDV in guinea pigs, CT may facilitate a more comprehensive overview of the condition and any significant comorbidities.

Accurate assessment of right ventricular wall thickness, myocardial visualization, and chamber dimensions is crucial in veterinary cardiology but remains understudied in dogs. This prospective observational study evaluated 10 healthy beagle dogs to compare three echocardiographic approaches for assessing right ventricular parameters: sector transducer, convex transducer, and convex transducer with contrast agent. The dogs' health was confirmed through physical examination, laboratory testing, and echocardiographic examinations. Statistical analyses were performed using paired sample t-tests, analysis of variance with Scheffé's post hoc test, Kruskal-Wallis tests for multiple comparisons, and intraclass correlation coefficients (ICCs) for observer reliability, with significance set at p < 0.05. Using a myocardial visibility and delineation scoring system, the study demonstrated that convex transducers offer superior visualization and inter-observer agreement, particularly in near-field segments (ICC: 0.12-0.92 vs. 0.06-0.73). Apical visualization of the right ventricle was significantly improved by contrast-enhanced echocardiography, thereby enhancing the reliability of right ventricular fractional area change measurements (mean RVFAC, 36.1% ± 7.3% with contrast, ICC 0.7). Additionally, myocardial-chamber delineation was improved by contrast-enhanced echocardiography, which highlighted its potential for evaluating specific pathological conditions, such as myocardial tumors or lesions. This study compared different echocardiographic approaches, clearly identified each technique's clinical strengths and limitations, and emphasized the utility of convex transducers and contrast agents, particularly in near-field lesions and complex myocardial abnormalities assessment. These findings provide valuable insights into improving echocardiographic technique reliability and accuracy in veterinary cardiology and offer practical contributions to canine heart disease diagnosis and treatment planning.