Canine and feline abdominal arterioportal communications can be classified based on branching patterns in computed tomographic angiography.

Arterioportal vascular anomalies are communications between the splanchnic arteries and the portal system that represent a rare cause of presinusoidal portal hypertension in small animals. There is little information concerning the imaging findings of arterioportal communications in small animals and no classification could be found for radiologists and surgeons. The aims of this retrospective descriptive multicentric study were to describe the computed tomographic characteristics of arterioportal communications in a group of cats and dogs, and to propose a classification based on computed tomography (CT) angiographic anatomy. Computed tomography databases from multiple veterinary hospitals were searched for cats and dogs with a diagnosis of arterioportal communication. A total of 36 animals (33 dogs, three cats) met the inclusion criteria. There were 32 intrahepatic arterioportal malformations and four extrahepatic fistulae. The intrahepatic arterioportal malformations were classified as right divisional (11/32) and left divisional (21/32), and the left divisional were subclassified as left medial (16/21) and left lateral (4/21). One patient showed multiple intrahepatic arterioportal communications with concomitant left medial and left lateral conformations. Two patients with intrahepatic arteriovenous malformation showed concomitant congenital intrahepatic shunts. The proposed anatomical classification based on CT angiography could allow veterinary radiologists to have a more systematic approach and help improve the radiologist-surgeon communication.

A Comparison of Angular Values of the Pelvic Limb with Normal and Medial Patellar Luxation Stifles in Chihuahua Dogs Using Radiography and Computed Tomography.

OBJECTIVE: This article aimed to determine and compare the angular values of the pelvic limb in normal and medial patellar luxation (MPL) stifles in Chihuahuas using radiography and computed tomographic (CT) scan, to identify the relationship between pelvic limb angles and severity of MPL. In addition, radiographic and CT images were compared to determine the more suitable method of limb deformity assessment. METHODS: Sixty hindlimbs of Chihuahuas were divided into normal and grade 1, 2, 3 and 4 MPL groups. The pelvic limb angles in frontal and sagittal planes were evaluated on radiography and CT scan. Femoral and tibial torsion angles (FTA and TTA) were evaluated only by CT scan. All angles were compared among normal and MPL stifles and between radiography and CT scan. RESULTS: Based on the CT scan, the mechanical lateral distal femoral angle (mLDFA), anatomical caudal proximal femoral angle (aCdPFA), and TTA were related to the severity of MPL. The mLDFA and TTA were significantly increased (p < 0.05) in grade 4 MPL, while the aCdPFA was significantly decreased in grade 2, 3 and 4 MPL groups. There were significant differences of many angles between radiography and CT scan. CLINICAL SIGNIFICANCE: The angles related to MPL in Chihuahuas are aLDFA, mLDFA, aCdPFA and TTA. Radiography had some limitations for evaluating pelvic limb angles. The caudocranial radiograph is recommended for the assessment of the distal femoral angles, while the craniocaudal radiograph is for the tibial angles.