the electron current energy when hitting the tungsten target is converted into photons. However, instead of spinning a small target anode in order to dissipate waste heat, the electron current focus spot is swept along a large stationary target anode. The electron current sweep is aimed using wound copper coil magnetic deflection yokes, as in a cathode ray tube (CRT). However, the entire structure of the cathode, deflection yokes, anode and overall vacuum tube size is much larger, therefore made out of steel, not glass, with the main central open midsection of the vacuum tube hollow, leaving room for the scan table and object or person to lie while the scan is performed. Future Whether the inherent sweep-speed advantage will maintain commercial viability of the EBT design remains unclear at this time. As of 2002, one major company owns and offers models in both competing designs, with engineering cross-pollination of techniques between the product design teams. As of 2005, it increasingly appears that the spiral CT designs, especially those with 64 detector rows, 3×360°/sec rotation speeds, and designed for cardiac imaging, are largely replacing the EBT design from a commercial and medical perspective. However, EBT still offers sweep speeds of effectively 50×360°/sec rotation speeds and lower radiation exposure. The latest version of the EBT eSpeed offers a 33 ms sweep time. This technology continues to represent the fastest commercial CT temporal resolution. Since 2008, a single development company has taken the lead on continued development, support and sales of EBT imaging products. The EBT scanner continues to stay in use globally due to the high accuracy, superior repeatability and ultra low dose abilities over high dose mechanical scanners. As of the early 2020s EBT imaging had become completely obsolete and had been replaced by multidetector CT imaging everywhere. References Electron beam X-ray computed tomography