Veterinary Radiology & Ultrasound最新文献

Computed tomography (CT) is commonly used in the staging of hepatic masses and for liver lobectomy planning. Mass location is an important factor in determining the feasibility of resection, including surgical technique and the likelihood of surgical complications. The objectives of this retrospective descriptive cross-sectional, observer agreement, method comparison study were to assess the reliability of CT in correctly determining the hepatic division and lobar site of origin of feline primary nonhematopoietic hepatic masses, compared with surgically confirmed locations. Furthermore, it provides an overview of the types and locations of liver masses found in a cohort of cats. Pre- and postcontrast CT images of 21 cats were independently and simultaneously reviewed by two observers. Intra- and interobserver agreements and descriptive statistics on demographic and histological diagnoses were calculated. Based on surgical assessment, it was found that masses most frequently originated from the left hepatic division (13/24, 54%). The most frequent lobar origins were the left lateral (8/24, 33%), left medial (5/24, 21%), and right medial lobes (5/24, 21%). No masses were found originating from the right lateral lobe. CT correctly determined hepatic division and lobar origin in 76% of cases, with good-to-excellent intra- and interobserver agreement. The hepatic division had higher agreements overall for both observers. Most of the masses were benign (17/21, 81%), and the most prevalent histological diagnoses were biliary cystadenoma (11/21, 52%) and hepatocellular adenoma (6/21, 29%). Findings suggest that postcontrast CT is a reliable method for correctly determining hepatic mass division and lobar origin in cats.

A 14-month-old female spayed, small crossbred rabbit presented for assessment of a small, hard subcutaneous nodule in the right axilla. Serum biochemistry showed markedly increased serum ALP activity. A whole-body CT revealed an aggressive, monostotic osteolytic, and productive lesion within the left alveolar process of the maxilla, with erosion of the alveolar bone and secondary premolar depression. Innumerable metastatic osseous masses were present throughout the body, including cerebral, pulmonary, hepatic, subcutaneous, and skeletal muscular metastases. Postmortem findings confirmed widespread, metastatic osteosarcoma, with the primary lesion within the left maxilla.

This case report describes a three-year-old male intact border collie diagnosed with canine papillomavirus type 1 (CPV-1+) oral papillomas resistant to standard-of-care. With time, he developed lesions consistent with squamous cell carcinoma. Malignant tumors were incompletely excised and treated with definitive external beam radiation therapy (45 Gy, 3 Gy × 15 daily). The remaining oral cavity received 27 Gy (1.8 Gy x 15 daily) to treat the disseminated oral papillomatosis. A temporary treatment delay of 2 weeks was instituted due to grade 3 mucositis. The patient remained in complete remission after 10 months from radiotherapy. No tumor recurrences were noted by the owners after >1 year from treatment.

An 8-year-old mixed-breed dog was presented with cervical hyperesthesia, tetraparesis, and mild proprioceptive ataxia in all four limbs. 3 Tesla MRI showed a dorsal compressive intradural-extramedullary mass at the level of C1-C2, isointense to the gray matter with a hypointense ventral core on T2 weighted images (WI), isointense on T1WI, with a strong and homogeneous contrast enhancement. A C1-C2 partial dorsal laminectomy was performed, and the lesion was removed en bloc. The histopathological and immunohistochemical analysis defined the diagnosis of inflammatory pseudotumor.

A 16-year-old pony gelding presented with epistaxis and a head tilt. Referral skull radiographs suggested an ethmoid hematoma. Concurrent neurologic abnormalities prompted contrast-enhanced CT of the head and cranial neck, revealing numerous hyperattenuating masses throughout the brain and paranasal sinuses, along with a large osteolytic mass in the second cervical vertebra. The vertebral mass extended into the vertebral canal, causing focal extradural compressive myelopathy. These findings were inconsistent with ethmoid hematoma and metastatic hemangiosarcoma or malignant melanoma were prioritized as potential causes for the clinical signs. Postmortem examination confirmed the sinonasal, intracranial, and vertebral masses as hemangiosarcoma, and additionally revealed innumerable thoracoabdominal metastatic lesions and hemorrhagic foci. A final diagnosis of disseminated hemangiosarcoma was made. In this study, CT proved invaluable for evaluating the severity and characterizing regional disease and neural involvement, directly affecting case management decisions.

Susceptibility-weighted imaging (SWI) is a gradient echo (GE) MRI sequence. Intravenous administration of gadolinium (Gd) may affect GE images, but its effect on SWI has not been investigated in veterinary medicine. This cross-sectional prospective study evaluated the effects of Gd on SWI. Seventy-one dogs that underwent brain MRI were included and distributed in two groups. Susceptibility-weighted imaging was performed pre- and postcontrast, obtained immediately after Gd administration (Group A: n = 35) or delayed (Group B: n = 36; median delay 19.9 min). Pre- and post-Gd SWI were analyzed for signal intensity changes in the lentiform nuclei of gray matter (GM), in the centrum semiovale of white matter (WM), and in brain lesions. No difference in GM signal intensity was identified in either group between pre- and postcontrast images (Group A, P = .395; Group B, P = .895). In group A, WM signal intensity was lower in pre- than post-Gd sequences (P = .019). Brain lesions were identified in 30/71 (41%) cases; the signal intensity of intracranial lesions was significantly lower in pre- than post-Gd images in both groups (P < .001); the number of lesions influenced the difference in signal intensity in group B (P = .043). Susceptibility artifacts did not change in appearance between pre- and postcontrast images in either the normal brain or in parenchymal lesions. In conclusion, Gd may modify the signal intensity of WM and brain lesions but does not affect the susceptibility artifacts and does not interfere with SWI interpretation.

There are no published reports describing the anatomic variations of the phrenicoabdominal (PhAbd) veins in cats. The aim of this study was to evaluate the anatomic variations of the PhAbd veins in cats without adrenal disease. This is an anatomic study. Abdominal CT images of cats acquired from January 2021 to February 2023 were retrospectively reviewed. Inclusion criteria were the presence of pre- and postcontrast CT images of the abdomen and the absence of any abdominal diseases that compromise the left and right PhAbd veins visualization. A total of 128 cats were included. Three different vascular anatomic variations were found in the distal pericaval segment of the left phrenicoabdominal (LPhAbd) vein. In the first type, found in 65 cases (50.8%), the LPhAbd vein drained directly into the caudal vena cava. In the second type defined IIa, found in 25 cases (19.5%), the LPhAbd vein drained into the distal third of the left renal vein, less than 5 mm from its opening into the caudal vena cava. In the third type defined IIb, found in 38 cases (29.7%), the LPhAbd vein drained into the distal third of the left renal vein, more than 5 mm from its opening into the caudal vena cava. The right phrenicoabdominal vein had a consistent path and drained into the caudal vena cava in all cases. The knowledge of these vascular variations is expected to help the surgeon during adrenalectomy due to masses with vascular invasion in cats.

In veterinary radiotherapy, highly reproducible immobilization is important for accurate irradiation. Consequently, we developed a new reusable head-immobilization method for dogs using cylinders. This study aimed to compare the accuracy of our novel immobilization method using cylinders with that of bite-block type immobilization methods. Three immobilization methods were compared: bite-block only, bite-block combined with torso immobilization, and immobilization using cylinders. Five beagles with canine teeth underwent CT five times for each of the three immobilization methods. One beagle without canine teeth underwent CT 15 times using each method. Three maxillary landmarks (maxillary incisor, frontal sinus, and occipital bone) and one mandibular landmark (mandibular incisor) were established, and the errors in each immobilization method were measured. For all head landmarks, the error in the immobilization method using cylinders was the most reproducible, with the smallest errors. No significant differences were observed in the time required for immobilization. Although there were limitations (such as the use of dogs from a single breed, a single episode of anesthesia, no disassembly of the immobilization system between scans, and the same person performing the positioning on the same day), we found our new reusable immobilization method using cylinders was the most accurate among the three compared methods. This was a proof-of-principle study to evaluate head immobilization using cylinders, and further investigations are needed to confirm its clinical utility.