Veterinary Radiology & Ultrasound最新文献

A 3-year-old male castrated domestic ferret presented with a 24 h history of lethargy, weakness, and anorexia. The ferret was tachypneic, painful, dehydrated, pale, and obtunded on physical examination. Radiographs and thoracic CT were utilized to diagnose a 360° right cranial lung lobe torsion (LLT) with secondary pneumothorax and pleural effusion. This was confirmed on gross necropsy and histopathology. The LLT was suspected to be secondary to previous trauma based on chronic bilateral rib fractures. Lung lobe torsions are life-threatening conditions infrequently described in veterinary medicine. Based on our review of the literature, this is the first description of an LLT in a ferret.

The identification of a solitary splenic mass on abdominal ultrasound is a common occurrence; however, diagnosis based on imaging alone remains a challenge. Multiple studies have tried to identify key characteristics that denote a benign or malignant lesion before splenectomy. Differential diagnoses commonly include hemangiosarcoma, hematoma, extramedullary hematopoiesis, and lymphoid hyperplasia. While comprehensive, this list fails to consider the less frequent neoplasms such as splenic stromal sarcoma. This retrospective study aimed to evaluate 13 dogs diagnosed with canine splenic stromal sarcoma and determine common characteristics noted on abdominal ultrasound. Masses were solid, without evidence of cavitation, and arising from the mid-body of the spleen. While abdominal ultrasound does not provide a definitive diagnosis for splenic stromal sarcoma, it should be considered when identifying a solitary, solid, noncavitary splenic mass.

A 4-year-old Nigerian Dwarf wether presented for chronic regurgitation and cervical swelling of three years duration. Physical examination revealed a large ventral cervical mass. The goat made repeated attempts to swallow and regurgitate, but the mass did not change significantly in size. Cervical radiographs revealed segmental esophageal dilation to the level of the thoracic inlet. CT revealed a transitional seventh cervical vertebra with fused right and left ribs, resulting in extramural esophageal compression and obstruction at the level of the thoracic inlet. This is the first report of a cervical rib causing megaesophagus in a goat.

There has been increasing interest in the literature on primary thyroid diseases in guinea pigs, which are believed to be underdiagnosed. This study describes the size and characteristics of the thyroid gland on ultrasound (US) and CT examinations in the guinea pig (Cavia porcellus) without evidence of thyroid pathology and examines the possible use of US as a routine examination for thyroid diseases. This prospective and anatomical study included 20 guinea pigs that underwent CT for dental pathologies and US for thyroid gland (TG) examination. Based on US and CT images, this study evaluated the thyroid lobe dimensions (length, height, and width) and shape. Echogenicity and homogeneity were assessed on US images, and attenuation values (HU) and homogeneity were evaluated on CT images. All animals underwent CT and US examinations under anesthesia. Thyroid lobes appeared more frequently as fusiform on CT (65%) and oval on US scans (67.5%). The attenuation values on CT scans were homogeneous. On the US scans, the TG was more frequently hypoechoic. No statistically significant differences were found between the size of the right and left thyroid lobes, both with CT and US. A statistically significant difference was found between the length values on CT and US. The US and CT thyroid gland dimensions, shape, and appearance were described. Both CT and US are useful techniques for evaluating the TG in guinea pigs.

The ultrasonographic appearance of the ileocecocolic junction (ICCJ), comprising the ileocolic junction (ICJ) and the cecocolic junction (CCJ), has not been established in dogs. The purpose of this prospective study was (1) to evaluate the feasibility and technique of systematic ultrasonographic evaluation of the ICJ and CCJ and (2) to describe its ultrasonographic features. Abdominal ultrasound was performed in 102 fasted dogs, free of digestive signs. The time required to identify the ICJ using a standardized method was recorded for each operator and compared among four experienced ultrasonographers (ECVDI certified and associated member ECVDI) and two previously trained ECVDI residents to evaluate the feasibility of the technique. Measurements were obtained for the ICJ wall thickness. Evaluation of the contents and peristalsis of the ICJ was recorded for descriptive purposes. The easiest way to identify the ICJ was to follow the colon proximally from the urinary bladder to the ICJ. The probe was then rotated anticlockwise and shifted slightly laterally while increasing the pressure to obtain a longitudinal section of the ICJ. The ICJ was identified in less than 2 min in 98% of cases by experienced ultrasonographers and in 86% of cases by ECVDI residents. The canine ICJ appears as a short invagination of the ileum into the colon, whereas the CCJ appears as a small opening of the colon within the cecum. This study suggests that it is possible to nearly systematically identify the ICCJ with ultrasound in dogs using the described method and provides reference values for its ultrasonographic measurements.

Computed tomography is commonly used to evaluate feline otic disease; however, published studies characterizing the CT appearance of ear canal neoplasia are limited. The purpose of this multicenter, retrospective, secondary analysis, cross-sectional study was to describe the CT features of histopathologically confirmed feline ear canal neoplasia. The CT studies of 25 cats with ear canal neoplasia were prospectively scored by consensus of two veterinary radiologists. Recorded parameters were the presence of focal or multifocal tissue enlargement (mass/masses), lesion shape, location of the center of mass, attenuation characteristics, features of contrast enhancement, involvement of otic structures, calvarial and brain changes, changes of nearby structures, and lymphadenopathy. There was a significant overlap of CT findings between cats with malignant ceruminous gland neoplasia, ceruminous gland adenoma, and squamous cell carcinoma (SCC). Ceruminous gland adenoma was typically homogeneous in attenuation with homogeneous contrast enhancement and no intralesional fluid accumulations (IFAs) or involvement of adjacent structures. In contrast, SCC consistently had heterogeneous attenuation, heterogeneous contrast enhancement, IFAs, and involvement/invasion of adjacent structures. Malignant ceruminous gland neoplasia had variable attenuation and pattern of contrast enhancement with occasional IFAs and occasional involvement/invasion of adjacent structures. Knowledge of these imaging features will inform the creation of prioritized differential diagnosis lists. However, a biopsy is required to confirm the diagnosis.

Primary frontal sinus squamous cell carcinoma (PFSSCC) represents a rare disease in dogs, and there is a general paucity of information in the current veterinary literature regarding its presentation and response to radiation therapy. The objective of this retrospective observational study was to describe a series of dogs diagnosed with PFSSCC and report their response to radiation therapy. Medical records of dogs with a diagnosis of PFSSCC were reviewed. Data collected included signalment, presenting complaint, clinicopathologic and diagnostic imaging findings, treatment, therapeutic response, and date of death or last follow-up. Eight cases of PFSSCC in dogs were treated with radiation therapy at the authors' institution. Three of these dogs were treated with coarse-fractionated radiation therapy. One dog was euthanized due to an unrelated cause 36 months after completing the radiation therapy. The second and third dogs survived 18 and 3 months, respectively, from the end of treatment to death due to PFSCC. Five further dogs were treated with a more fractionated protocol (Monday-Wednesday-Friday schedule). The median survival time for all patients was 7.5 months (range 2-36 months). Despite the small number of cases and variation in the radiation protocols used, the treatment outcomes in these eight dogs suggest that radiation therapy is potentially a viable treatment option for dogs with PFSSCC and that coarse fractionation might be an appropriate approach if more finely fractionated protocols are not possible.

In veterinary medicine, PET/CT scans are generally performed with the patient under general anesthesia. The aim of this prospective crossover study was to compare the musculoskeletal uptake of ¹⁸F-FDG and radiation doses to workers during PET/CT studies of healthy dogs and cats between sedation and general anesthesia. Volume and maximal standard uptake values (SUVmax) values of abnormal ¹⁸F-FDG uptake in the skeletal musculature, presence of misregistration artifact, and radiation doses to workers for each PET/CT study were recorded. Sedation was associated with increased volume of ¹⁸F-FDG uptake in the musculature of the thoracic limbs (p = .01), cervical (p = .02), and thoracic (p = .03) spine. Increased volume and SUVmax of the musculature assessed altogether were associated with the lighter degree of sedation (p = .04 for both). A significant decrease in the odds of misregistration artifact was observed for anesthetized animals in comparison with sedated (OR: 0.0, 95% CI: 0.0-0.0, p = .01). Radiation doses to workers were significantly higher for sedation compared with general anesthesia (p = .01) and for the anesthesia technician compared with the nuclear medicine technologist (p = .01). Use of sedation for PET/CT studies in dogs and cats is feasible. However, it is associated with increased physiologic musculoskeletal uptake of ¹⁸F-FDG in the thoracic limbs, cervical, and thoracic spine, with increased frequency of misregistration artifact, and with increased radiation doses to workers. These limitations can be overcome by recognition of the uptake pattern and monitoring/rotation of the involved staff at institutions where a high caseload is expected.

Accurate determination of the gross target volume (GTV) is critical in radiation treatment planning, as errors could result in underdosing of the tumor or overdosing of nearby organs at risk. This multicenter retrospective observational serial measurement study evaluated the effects of variations in MRI slice thickness and a time delay between the diagnostic (MRI-1) and RT planning (MRI-2) MRIs GTV contouring in dogs with presumed meningiomas. The hypothesis was that the GTV would increase in size with time on T1-weighted sequences with contrast. Inclusion required paired MRI acquisition within 3 months. The GTV was contoured on each MRI. Forty-six dogs were included. Slice thickness was significantly different (P < .001) between MRIs: MRI-1 had a median of 3.9 mm (range: 0.8-6 mm; only two dogs <2 mm), and MRI-2 had a median of 0.9 mm (range: 0.6-4.5 mm; only two dogs >2 mm). The median time between MRIs was 22 days (range: 8-74 days). The MRI-1 GTV was significantly different from MRI-2 GTV (P < .0001); thirty (65%) were larger, five were equal in size, and 12 were smaller than the MRI-2 GTV. This difference in GTV is likely due to the slice thickness differences between MRI acquisitions rather than changes in tumor size due to the short time interval between MRI-1 and MRI-2. This finding highlights the differences between diagnostic and RT treatment-planning MRIs. For brain tumor target contouring, an MRI at the same time as the RT planning CT with <1 mm slice thickness, 3D acquisitions, and anisotropic voxel is recommended.

This retrospective study aims to describe baseline and follow-up imaging findings in subchondral and trabecular bone damage occurring outside of the sagittal groove in the proximal phalanx (P1) glenoid in a case series of lame Warmblood horses. Thirteen lame horses (16 forelimbs) with standing magnetic resonance imaging (sMRI) evidence of nonsagittal groove glenoid subchondral and trabecular bone injury of P1 as the main lesion were included. All injuries were located at the medial aspect of the P1 glenoid. At sMRI, changes included subchondral bone plate thickening and trabecular sclerosis, bone marrow edema-like signal, subchondral bone resorption (11/16), and new bone production (8/16). Subchondral bone resorption in the transverse plane was linear (8/11), round (2/11), or ill-defined (1/11). Sclerosis, bone resorption, and new bone production were seen radiographically in 10, 4, and 5 limbs, respectively. All limbs had concurrent metacarpal condyle sMRI imaging abnormalities, osteophytosis, and joint effusion. Follow-up sMRIs were obtained in 8 of 16 limbs, five of which showing progression of the resorptive lesion. One horse encountered a comminuted fracture of the affected P1 18 months after the follow-up sMRI examination. The imaging appearance of the medial glenoid bone injuries of P1 in this case series is consistent with chronic bone overload. The linear configuration of bone resorption seen in eight lesions suggests short, incomplete stress fractures, which is supported by the ultimate catastrophic fracture occurring in one case.