Semantic divergence ends in practical convergence

Slice wars erupted nearly a decade ago with the introduction of quadslice CT scanners. Since then, it's been one battle after another, as the industry jumped to eight slices per rotation, then 16, up to 32 and 40, back to 16 (with generators of varying power), then 64. Along the way, semantic skirmishes have broken out over what was a slice and whether multislice CT should be called MD (multidetector) CT.

In all the pulling and pushing, vendors found their own voices in technologies that began to turn the debate from slices and terminology to clinical relevance. Now, as the imaging community makes final plans for the annual trek to Chicago, vendors are putting the final touches on their messages, and these are beginning to look more and more alike.

• More slices deliver clinical advantages. The leading edge of 64-slice scanners has become the trailing edge of premium CT. Vendors will argue that more slices are not the answer. How they generate the slices is the trick. Dual-beam CT increases temporal resolution. So do single-beam 128- and 256-slice CT. All will point to the proof in images lining their booths.

• Multi-energy CT unmasks the hidden. Dual-beam CT is one way to interrogate tissues at different x-ray energies but not the only way. Look for CT using "electronic beam switching" as an alternative to the "mechanical" method that uses two x-ray tubes mounted on a gantry. Further out is spectral CT and a photon-counting detector to assess different energies emitted by a single x-ray beam.

• Upgrading CTs in the field. Not many customers are buying scanners capable of fewer than 16 slices per rotation, but they might if these rock-bottom-priced scanners could be upgraded without a forklift. As 64-slice CT careens toward becoming the de facto standard of any state-of-the-art radiology operation, vendors have had to blaze field-upgradable paths from 32 as well. This kind of flexibility will evolve, as gantry swaps become a thing of the past and engineers figure ways to add detector rows when needed.

• Productivity. This rule of CT will take on increasing importance as reimbursements in the U.S. get tighter. Engineers are coming up with faster algorithms and more powerful computing engines to keep pace with the growing volumes of data produced by faster scanners running advanced applications as well as the automation that users are demanding to process the rising tide of routine cases.