1. Gd: MR Venography Martin R. Prince, MD, PhD

2. Strategies to reduce Gd Dose shorten scan duration time bolus for center of k-space digital subtraction higher relaxivity reduce cardiac output inject vessel directly [Gd] arterial = + [Gd] venous Injection Rate Cardiac Output

3. 1 T1T1 = R 1 [Gd] Venous Blood 1 T1T1 = R 1 Injection rate Cardiac output Arterial Blood 100:1 dilution 50:1 dilution

4. 0.1 0 1 5 10 20 30 40 50 60 100 %Gd:DTPA Contrast Agent Dilution 3D SPGR TR/TE/Flip 6.5/1/45º

5. TE=1TE=10

6. TE=5 TE=3TE=2TE=1

7. Conventional Upper Extremity Venography Radiation exposure Multiple stations Variable flow rate Difficult to time breath holding Large dose of iodinated contrast Contrast dilution obscures central veins

8. Large caliber iv in forearm Elevate arms with cushions Coil: one arm torso coil two arms body coil Sagittal Locator Coronal 3D Spoiled Gradient Echo 5cc Gd:DTPA in 250 cc NS (50:1) Load 2, 60 cc syringes for each arm Use automatic valve to instantly switch from 1st to 2nd syringe Landmark Direct MR Venography Protocol

9. Coronal Plane Anterior to Clavicle Posterior to Right Atrium Superior to Mandible Use Maximum Field-of-View Fast scan to permit breath holding thick slices (4-5mm) zero interpolation (ZIP x 2) partial Fourier imaging (0.5 NEX) Prescription of 3D Imaging Volume

10. inject one entire syringe (60 ml) Immediately switch to 2nd syringe start imaging with breath holding during injection of 2nd 60ml syringe Gd injection

11. Single Operator Strategy Inject one arm at a time Left arm injection Right arm injection

12. Two Operator Strategy : Inject both arms simultaneously

13. Vessels that are easily accessible arm vein pedal vein umbilical vein caput medussa brachial artery common femoral artery

14. Summary IV injection excellent venograms dilute Gd at least 10:1 inject large volumes two 60 ml syringes per arm inject rapidly breath holding essential repeat as necessary Courtesy of James F. M. Meaney. MD