MR-venography using manual flow augmentation in an open low field MR system.

objective: To evaluate the feasibility of signal enhancement in the deep ve ins by means of manual compression of the calf (flow augmentation) as a new approach to MR venography in open configuration, low-field systems. Method s: 10 healthy volunteers underwent MR venography of the calf unconstrained and during short localized manual compression. Gradient recalled echo seque nces (FLASH, FISP) with repeated single slice acquisition and first-order g radient motion refocussing were tested in four protocols with and without a rterial presaturation slabs (scan time 2.2-5.0 s per slice). The effect on flow enhancement was rated by means of a signal score. Interventional acces sories, particularly an in-room LCD screen, were required for interactive a pplication of compression manoeuvres. Results: Sequences with arterial pres aturation slabs were superior to those without regardless of the longer acq uisition times. Careful targeting of compression to the mid-time of data ac quisition was crucial to obtain marked flow acceleration. Enhancement was b est in the case of proximally applied calf compression. Signal improvement was consistently achieved in the proximal parts of the posterior tibial and peroneal veins, but was only seen in 4/10 volunteers in the distal part of the anterior tibial vein. Conclusion: Flow augmentation by means of manual calf compression is a simple and effective complementary approach to MR ve nography in open configuration, low field MR systems.