1. Norwood procedure using modified Blalock–Taussig shunt: Beware of the circle of Willis 
Selma O. Algra, MD, Floris Groenendaal, MD, Ton Schouten, MD, Felix Haas, MD 
The Journal of Thoracic and Cardiovascular Surgery 
Volume 141, Issue 3, Pages (March 2011)
DOI: /j.jtcvs
Copyright © 2011 The American Association for Thoracic Surgery Terms and Conditions

2. Figure 1
Magnetic resonance angiography of the cerebral arteries. A, Right carotid artery. B, Left carotid artery. C, Basilar artery.
The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /j.jtcvs )
Copyright © 2011 The American Association for Thoracic Surgery Terms and Conditions

3. Figure 2
Magnetic resonance angiography of circle of Willis. Absent left posterior communicating artery (arrow).
The Journal of Thoracic and Cardiovascular Surgery  , DOI: ( /j.jtcvs )
Copyright © 2011 The American Association for Thoracic Surgery Terms and Conditions