Technologist Track

SCMR 22nd Annual Scientific Sessions

1 - Incidental finding of Double Aortic Arch; A quick Cardiac MRI Protocol for Cardiovascular Assessment.

Presenter(s)

• 

  Raj Kumar Soundarajan, BSc

  Senior MRI Research Radiographer
  University of Oxford

Author Only(s)

• 

  Betty Raman, MD

  Cardiovascular Research Fellow, Oxford Centre for Clinical Cardiovascular Magnetic Resonance Research
  University of Oxford
• JF

  Jane Francis, FSCMR

  Chief technologist
  Oxford Centre for Clinical Magnetic Resonance Research
• 

  Saul Myerson, MD

  Associate Professor, Consultant Cardiologist Clinical Lead
  University of Oxford

Background:

Description of clinical presentation: A 52- year old gentleman presented with haemoptysis and a history of Chronic Obstructive Pulmonary Disease. CT Pulmonary Angiogram was performed to rule out the respiratory cause and identified an incidental finding of congenital Double Aortic Arch (DAA). Transthoracic echocardiography showed normal cardiac function, with an EF of 59%, a dilated right ventricle with preserved function and mildly dilated aortic root. Further Cardiac MRI (CMR) investigation was suggested to delineate the congenital anatomy of the great vessels and its relationship to other cardiac structures.

Methods:

The scan was performed on 1.5T Siemens Avanto Fit scanner. The CMR protocol consisted the following.

• Three-plane Localizer.


• Pseudo-3D Axial SSFP (Steady-state free precision) white blood anatomical imaging.


• 2D Coronal HASTE (Half-Fourier acquisition single-shot turbo spin echo) dark blood anatomical imaging.


• 3D SSFP respiratory navigator-non contrast MR Angiography.


• TrueFISP SSFP pilot for localization of cardiac chambers (2, 4 chamber and short axis).


• TrueFISP SSFP cine imaging for cardiac and aortic function (Horizontal & Vertical long axis of left ventricle, Aortic outflow tract, transverse and oblique sagittal view of aortic arch).


• Velocity encoded 2D Phase Contrast cine for aortic haemodynamic assessment (Through plane flow at sinus of Valsalva and an In-plane flow on both aortic arch views).

An outline and the benefits for each sequence with scan time are explained in the table below.

Results:

Most important findings: CMR demonstrated normal biventricular functions. Non stenotic DAA with dominant right arch 20mm (Left arch 15mm). Right subclavian, right common carotid artery originates separately from right arch and left subclavian, left common carotid artery originates from small left arch. No obstruction/compression to the surrounding organs are noted.

Conclusion:

Learning point from this case: Typically DAA is an isolated, rare congenital aortic anomaly caused by persistence of both primitive 4^th arches and dorsal aortas to forms a vascular ring encircling the trachea and oesophagus. It is occasionally asymptomatic but more frequently associated with tracheoesophageal compression, manifesting as upper airway obstruction and swallowing difficulties. Treatment is surgical, based on the severity of the symptoms.
DAA can be diagnosed by conventional esophagography, computed tomography or by digital angiography but CMR has a major advantage over others because of good spatial and high temporal resolution and can provide accurate information for surgical planning and for the assessment of complex cardiovascular anatomy and detailed function in a single 20min examination.