• The improvement of diagnosis of CHD, due to larger coverage of vascular territories, higher spatial resolution, faster acquisition and higher quality of MR-flow measurements using Vasovist in comparison with standard Gd-agent
  
• The improvement of image quality will be analysed by measuring the SNR, the CNR, the vessel sharpness. In addition, the overall image quality will be scored by three independent readers (scale: excellent, good, ok, bad)
  
• Ventricular volumes measured from the acquired data will be compared with respect to a reference
  
• The accuracy (standard deviation) and reproducibility of the flow measurements will be compared using the two different agents
  

• No secondary outcome measures.
  

We planned an intra-individual study, where 20 adult patients with CHD (e.g. Fallot Tetralogy, s/p corrective surgery, single ventricle s/p Fontan operation, aortic and pulmonary artery stenosis) will undergo two examinations. Both scans are aimed to assess different diagnostic parameter like angiography, cardiac anatomy, ventricular volume and flow.

The first clinically indicated scan in our clinically established imaging protocol is performed using a standard contrast agent. The second scan is performed using a new protocol with Vasovist within the next seven days. Informed consent for the additional second scan will be obtained. In order to optimise the scan protocol for Vasovist we plan a pilot phase using three patients. Dosage of the two contrast agents will be within the approved dose. Any adverse events will be immediately reported. The following diagnostic parameters will be assessed and compared between standard Gadolinium (Gd) agent and Vasovist.

1. MR-Angiography (MRA): assessment of the MRA quality of the large systemic and the pulmonary vessel (arterial and venous) by measuring the Contrast-to-Noise Ratio (CNR) and the vessel sharpness. In addition, the overall image-quality will be scored by three independent readers (scale: excellent, good, ok, bad).
2. Cardiac Anatomy: assessment of image quality of the cardiac anatomy from 3D single/dual phase MRI by measuring Signal-to-Noise Ratio (SNR) and CNR as well as assessing the overall image quality by three independent readers (scale: excellent, good, ok, bad).
3. Ventricular Volumes: comparison of systolic and diastolic volumes measured from multi-slice 2D short axis cine MRI, two single phases 3D whole heart MRI (diastole and systole).
4. Flow: the different flow values will be measured in the large vessels using the Phase Contrast Angio (PCA) data. Furthermore, the flow reproducibility will be determined by using two scans. The overall scan-time to assess all these parameter will be approximately 40 minutes. The intra-individual study allows a direct comparison of the different parameters in a number of vascular territories.