Powerpoint presentation

Electron beam CT Images are obtained in less than 100ms the source is not an x ray tube but rather a focused , steered and microwave accelerated electron beam on a tungsten target The target covers one half of the imaging circle , the detector array covers the other half Electron beam CT is principally applied to cardiac imaging in the form of coronary angiogram Spiral CT This was introduced in 1989 and is now the standard CT imager Basically if the third or the fourth generation scanner is caused to continuously rotate while the

patient couch is moved through the imaging plane , the spiral CT results The development of the slip rings has made this possible Slip rings Technology is required to for data transfer from the rotating gantry In a spiral CT coiled wires are not present , which necessitate returning of the gantry to the original position , wasting time Slip rings

Before the slip ring technology was developed , the high tension wires that supplied the power to the gantry , was made via cables

This caused a twist in the cables when the gantry took a turn

Slip rings are large circumferentially conducting rings that allow power to be conducted to the tube on the CT gantry via electrical brushes rather than cables . The gantry is thus able to continuously rotate in one direction Default Design...