NEW YORKThe main challenges in the continuing development
of low-dose spiral CT screening for lung cancer are cost, flow,
and efficiency, Stanley H. Fox, PhD, General Electric Med
Systems, Milwaukee, said at the Second International Conference on
Screening for Lung Cancer.
With todays technology, Dr. Fox said, the cost target per
screening CT scan is about $75. With improvements, he added, that
should eventually drop to $50. We believe we can screen up to
10 to 12 patients an hour, cutting the cost dramatically, he said.
The company is focusing on the flow process as one way to increase
efficiency. Diagnostic and high-resolution studies, if needed, Dr.
Fox noted, should be performed immediately after the initial low-dose
study. You dont have to reposition the patient, he
said. You dont have to call him back. You can save a lot
of trouble. Building this capability into the system is
probably the biggest challenge here, he said.
Another key element is computer-aided diagnosis. Equipment is being
designed to quantify any changes seen between screenings and to
include a database that will permit autoregistration with prior
lesions. Vessel and bronchi tracking may also be built in. In
fact, Dr. Fox said, we may present all of this in a
volumetric display. A total electronic record-keeping system is
mandatory, he stressed.
In the rapid-fire CT mode, Dr. Fox said, one touch of a button should
set up the scanner. Automatic exposure control is being built in, he
added. Techniques to help reduce artifacts and noise in
the images are also being developed.
With todays scanners, the patient moves horizontally. In the
future, however, the table on which the patient is positioned may
move up and down as well, Dr. Fox said. This innovation, he
predicted, might enable a CT scan to be performed as quickly as a
chest x-ray, if not faster.
Higher resolution is also being investigated. The effective size of 1
× 1.25 mm at the isocenter may in time drop to 0.2 × 0.2
mm, Dr. Fox said, and slices per centimeter might rise to 20 or 25.
We believe that lung cancer screening is going to happen,
he said. In addition, he noted, technologic improvements to advance
lung cancer screening apply to chest radiology in general and
will be very useful in routine diagnostic work.