SCMR 22nd Annual Scientific Sessions
Description of Clinical Presentation: A 12 year old girl with a history of Tetralogy of Fallot post repair was referred for a routine follow-up cardiac MRI for assessment of ventricular volume, function and pulmonary regurgitation. Previous echocardiography revealed the absence of any residual left to right shunting.
On calculation of the Qp:Qs ratio, an unexpected value 1.6:1 was detected.
On further interrogation of the volumetric post-contrast 3D IR FLASH images, a small coronary sinus fenestration was detected.
The child was called back for dedicated cine and phase contrast imaging, which confirmed the presence of the pathology and the left to right shunting.
Diagnostic Techniques and Their Most Important Findings: Multivessel phase contrast imaging of SVC, RPA, LPA and DAO for calculation of Qp:Qs was performed, which revealed a small left to right shunting with Qp:Qs of 1.6:1.
Respiratory and ECG gated post-contrast 3D IR FLASH imaging accurately depicted the absence of atrial and ventricular septal defects, while an incidental coronary sinus fenestration was detected.
Dedicated oblique Trufisp cine sequences and in plane phase contrast imaging confirmed the presence of the pathology.
Learning Points from this Case: Due to the inherent turbulent flows encountered in the paediatric cardiovascular system, our centre routinely performs flow volume quantification using a multivessel technique, with Qp quantified by Q(RPA+LPA) and Qs quantified by Q(SVC+DAO). This case highlights the improved accuracy of this technique in children when compared with direct measurement of the aorta and MPA, in which the small left to right shunting would not be detected. Repeat calculation of Qp:Qs yielding the same result also highlights the excellent reproducibility of this calculation method.
Our case also showcases the high diagnostic image quality of the post-contrast 3D IR FLASH sequence utilising a slow contrast infusion protocol, with its ability to depict detailed anatomical structures with high precision.