#DEFINITION OF AORTIC ARCH HOW TO#
#DEFINITION OF AORTIC ARCH FREE#

#DEFINITION OF AORTIC ARCH FREE#

These techniques make free breathing MRI highly feasible with little or no requirement of sedation ( 5- 7). However, the availability of new techniques including compressed sensing, 3D ultra-shot echo time and 4D flow acquisition result in a significant reduction of scan time. Unfortunately, MRI is generally time consuming and it also requires general anesthesia in infants and most of the young children ( 3, 4). Three dimensional capabilities provide anatomic aortic arch relationships as well as the assessment of tracheal compression. Black blood and bright blood-both non-contrast-sequences as well as contrast enhanced MRA can be employed and are cardiac gated to reduce motion artifacts. MRI is an excellent multiplanar imaging modality that provides evaluation of aortic arch malformations without radiation exposure. This may favor its increasing use, especially in pediatric patients, as CT may be performed without use of anesthesia or breath-holding ( 2). High pitch spiral mode can be used without gating to drastically reduce cardiac pulsation artifacts ( 1). CT is usually performed without use of gating which further reduces the exposure. With the availability of new generation scanners that have advanced radiation dose reduction technologies, the radiation dose has reduced dramatically.

Both computed tomography (CT) and magnetic resonance imaging (MRA) are therefore indispensable for accurate description of pre-surgical anatomy.ĬT provides high spatial resolution evaluation of vascular anomalies and can be reformatted in multiple oblique planes to provide a complete assessment of the tracheal and esophageal compression simultaneously. However, it is operator-dependent, and as such, is challenging in evaluation of complex arch anomalies. Echocardiography is often used as the first imaging modality, especially in pediatric patients. Catheter angiography, another 2D technique, has also lost its charm due to the advent of other non-invasive imaging modalities. Another reason for not using them is that they are able to provide 2D information only. The use of conventional modalities, including barium esophagram, have fallen presently out of place because of acute difficulty in performing them, especially in pediatric patients. Various imaging modalities are available, and each has its own merits and demerits.

#DEFINITION OF AORTIC ARCH HOW TO#

And most importantly, we discuss how to properly approach a case with suspected aortic arch pathology. We also take stock of surgical parameters that influence various management strategies. In this review, we proceed to discuss various aortic arch malformations along with their associated aberrations. However, an exact knowledge of anatomy is essential to avoid unnecessary surgical complications. These techniques also provide a more detailed evaluation of the tracheo-esophageal anatomy which is not delineated clearly by the 2D imaging modalities like conventional radiography, esophagram and angiography. Currently, non-invasive multidetector three-dimensional (3D) CT and 3D MRA play a greater role in the detection and characterization of these anomalies. All these factors led to the need of invasive modalities like angiography for surgical planning. The upper gastrointestinal study also is relatively difficult to perform in pediatric patients. However, even if it is positive, this still would not depict the type of vascular anomaly. A negative esophagram may rule out the presence of vascular ring.

Historically, barium swallow study was the primary mode of investigation to look for evidence of indentations on the posterior wall of esophagus as seen on lateral view. The primary role of a radiologist is to detect these abnormalities and, importantly, to look for imaging features which indicate high risk of compression of the trachea and esophagus. Imaging plays a great role in the detection of these anomalies and thus helps much in accurate preoperative surgical decisions. These malformations can be isolated or they may be associated with other intracardiac and/or chromosomal defects. However, these can be symptomatic in the form of difficulty in breathing or swallowing. Clinically, these malformations can be asymptomatic in terms of their detection especially when imaging is being performed for some other reasons. These aberrations are the result of either abnormal persistence or involution of embryonic vascular segments. Accepted for publication Oct 17, 2017.Ĭongenital aortic arch malformations present a large spectrum of variations and anomalies that emanate from disordered embryogenesis of branchial arches. Keywords: Aortic arch vascular ring computed tomography angiography (CTA) magnetic resonance angiography (MRA)

Definition of aortic arch