MRI-Based Assessment of Neovasculariation in Carotid Plaque – A Novel Risk Marker for Plaque Rupture Michael Jerosch-Herold, PhD Associate Professor of Radiology Director of Physics for the Cardiac Imaging Program Brigham & Women’s Hospital

New 3.0 T Bilateral 8-Channel Carotid Array and Head- Holder for Reynold Carotid Study Coil mounted on a frame with head-holder consists of two curved paddles MGH Design Wiggins/Wald Reference: Hinton-Yates et al., TMRI Coils = pair of four 4.8 cm loops Head Holder

MRI Protocol for Dynamic Contrast Enhancement T1-weighted 3D fast gradient echo –TR/TE/flip angle: 4.3/2.3 ms/ 20° –3 mm slices –In-plane resolution: 0.7 x 0.7 mm –Time per dynamic view: 14 s With new 8-element neck phased array the time per dynamic view is reduced to 10 s.

Post-Processing Contrast-Enhancement in Carotid Wall

Kinetic Modeling (Kety-Schmidt Model) Arterial Input Venous Outflow Tissue Extraction (K trans ) vbvb Model Parameters Determined by Optimization at Pixel Level v b vascular volume K trans First order blood-to-tissue transfer rate constant Measured in vessel lumen K trans Parametric Map Ktrans*1e3 [1/min]

Examp Ktrans Parametric Map Ktrans*1e3 [1/s] T2 TSE: carotid plaque

Example of Test-Scan in Patient with 8-Channel Phased Array Coil