Use of Contrast-Enhanced MR Angiography (CE-MRA) for the Diagnosis of a Vascular Ring Anomaly in a Dog

Silke Hecht,William H Adams,Gordon A Conklin,April M Durant

doi:10.1155/2012/316530

Abstract

A 4-month-old female mixed breed dog was presented to the University of Tennessee College of Veterinary Medicine with a history of regurgitation and cachexia. Thoracic radiographs revealed focal megaesophagus cranial to the heart base. Magnetic resonance imaging (MRI) was performed. True fast imaging with steady-state precession (TrueFISP), fast low angle shot (FLASH), and short tau inversion recovery (STIR) sequences were acquired prior to contrast medium administration. Contrast-enhanced magnetic resonance angiography (CE-MRA) demonstrated focal megaesophagus and position of the aortic arch to the right of the esophagus. A small ductus diverticulum and an indistinct linear soft tissue band crossing the esophagus were also noted. Surgical exploration confirmed MR diagnosis of a persistent right aortic arch (PRAA) with left ligamentum arteriosum. The dog improved following surgery but was unable to be transitioned to dry food. To our knowledge this is the first report describing the use of CE-MRA for preoperative diagnosis and guided surgical treatment of a vascular ring anomaly in a dog.

Highlights

Persistent right aortic arch (PRAA) is the most common vascular ring anomaly in dogs, but other types have been reported and may require a different surgical approach [1]
An MR diagnosis of persistent right aortic arch with left ligamentum arteriosum and focal megaesophagus was made, and the owners opted for surgical correction
The presence of a left ligamentum arteriosum, connecting the pulmonary artery to the right aortic arch, results in compression of the esophagus which in turn leads to retention of food and esophageal dilation

Summary

Introduction

Persistent right aortic arch (PRAA) is the most common vascular ring anomaly in dogs, but other types have been reported and may require a different surgical approach [1]. A definitive diagnosis prior to surgical intervention is desirable to minimize prolonged anesthesia and associated complications. This report describes the successful preoperative diagnosis of a PRAA with left ligamentum arteriosum by means of contrast-enhanced MR angiography (CE-MRA)

Case Presentation

Findings

Discussion