Multidetector-row computed tomography of thoracic aortic anomalies in dogs and cats: Patent ductus arteriosus and vascular rings

Abstract

BackgroundDiagnosis of extracardiac intrathoracic vascular anomalies is of clinical importance, but remains challenging. Traditional imaging modalities, such as radiography, echocardiography, and angiography, are inherently limited by the difficulties of a 2-dimensional approach to a 3-dimensional object. We postulated that accurate characterization of malformations of the aorta would benefit from 3-dimensional assessment. Therefore, multidetector-row computed tomography (MDCT) was chosen as a 3-dimensional, new, and noninvasive imaging technique. The purpose of this study was to evaluate patients with 2 common diseases of the intrathoracic aorta, either patent ductus arteriosus or vascular ring anomaly, by contrast-enhanced 64-row computed tomography.ResultsElectrocardiography (ECG)-gated and thoracic nongated MDCT images were reviewed in identified cases of either a patent ductus arteriosus or vascular ring anomaly. Ductal size and morphology were determined in 6 dogs that underwent ECG-gated MDCT. Vascular ring anomalies were characterized in 7 dogs and 3 cats by ECG-gated MDCT or by a nongated thoracic standard protocol.Cardiac ECG-gated MDCT clearly displayed the morphology, length, and caliber of the patent ductus arteriosus in 6 affected dogs. Persistent right aortic arch was identified in 10 animals, 8 of which showed a coexisting aberrant left subclavian artery. A mild dilation of the proximal portion of the aberrant subclavian artery near its origin of the aorta was present in 4 dogs, and a diverticulum analogous to the human Kommerell's diverticulum was present in 2 cats.ConclusionsContrast-enhanced MDCT imaging of thoracic anomalies gives valuable information about the exact aortic arch configuration. Furthermore, MDCT was able to characterize the vascular branching patterns in dogs and cats with a persistent right aortic arch and the morphology and size of the patent ductus arteriosus in affected dogs. This additional information can be of help with regard to improved diagnoses of thoracic anomalies and the planning of surgical interventions.

Morphology and morphometry of ramification of the aortic arch in domestic shorthair cats in the clinical aspect

“…CT angiography or MR angiography is the method of choice for diagnosis of vascular disorders or malformations (13,14,27). The knowledge of the variations of aortic arch morphology in various species of animals is a prerequisite for a correct assessment of the results of imaging tests.…”

“…Modern, multi-row units provide high contrast image quality with detailed anatomy of a patient. CT angiography with intravenous contrast application together with multiplanar reconstruction (showing the studied structure in any chosen plane) and 3D reconstruction allows practitioners to evaluate blood vessel diseases with any related pathologies (14,27). The analysis of thus obtained images requires knowledge of clinical anatomy.…”

Aberrant right subclavian artery causing megaoesophagus in three cats

“…In dogs, ARSA is usually an incidental finding of thoracic CT carried out for unrelated reasons, but it can cause oesophageal constriction and megaoesophagus (Henjes et al . , Della Santa et al . ).…”

“…, Henjes et al . ). Long‐term medical management of megaoesophagus is usually unrewarding because the degree of oesophageal dilatation and dysfunction often increases with age (Orton ).…”

Comparison between echocardiographic and non‐ECG‐gated CT measurements in dogs

“…CT examination of the thoracic boundaries, mediastinum, pleura, lungs and bronchi is performed routinely in small animal veterinary medicine (Drees and others 2011a,b, Habing and others 2011, Henjes and others 2011, Mai 2011, Marolf and others 2011, Petite and Kirberger 2011, Saunders and others 2011, Schwarz and Johnson 2011, Armbrust and others 2012, Reetz and others 2012, Saulnier 2012, Kirberger and others 2013, Mesquita and others 2014), but comparatively little information has been published on the assessment of the cardiac structures (Henjes and others 2012, Park and others 2012, Drees and others 2013, Lee and others 2013, O'Brien and others 2013, Sieslack and others 2013). CT examination of the heart has often been hampered by image degradation due to motion artefacts.…”