As the battle for the computedtomography (CT) system with the
greatest number of slices continues to rage among technology
vendors, clinical practitioners are reaping the benefits. In recent
weeks, one company has installed its first 40-slice CT system and
another has received clearance to market a 64-slice system.
Siemens introduces two additions to their CT product
Siemens Medical Solutions (Malvern,PA) recently announced that
they have received FDA approval for two new CT systems: a 64-slice
system and a large-bore 16-slice system.
Built on the company's Sensation platform, the Siemens Somatom
Sensation 64 CT system provides 64 submillimeter slices per
rotation at a rotation speed of 0.37 seconds. According to Murat
Gungor, U.S. Marketing Manager for Somatom Sensation products,
several new technologies have made this system possible. "One of
them was the X-ray tube, the Stratontube," he noted. "It is a
direct cooling tube, and it cools down very fast. This allows us to
create two focal spots on the anode ofthe tube." This so-called
"Double z-Sampling" creates the two focal points in the anode by
precise deflection of the electron beam within the X-ray tube.
These two points generate two overlapping beams to pass the scan
field. "By this," he said, "we increase the number of readings we
get out of the scan, which allows us to reach the 64-slice
"Utilizing the company's Speed4D technology, "the 64-slice is
faster than the 16, but the real thing that this scanner gives is
the resolution - a 0.4-mm resolution,' said Gungor. "What we see
today is that everybody wants to have speed, but the real thing
that they are looking for is resolution. Compared with what we had
before, which was often 0.6 mm, this 0.4-mm resolution is a
dramatic change, and it will allow a lot of clinical applications,
such as cardiac scanning and other types of vascular scanning."
The first unit is currently being installed in Germany, and the
first U.S.installation is scheduled for June, with full commercial
availability expected in November.
Sensation Open 16
Siemens also received FDA clearance for their new large-bore
16-slice CT system, the Somatom Sensation Open (Figure). This new
system has an 82-cm gantry bore with an 82-cm extended
field-of-view. "It has the widest field-of-view," said Gungor. "You
basically image everything that goes into that gantry."
Gungor explained that the main purpose of this new system is to
give the power of 16-slice CT to different areas ofthe hospital.
The large gantry opening allows greater patient access for
interventional procedures and is useful in radiation therapy
planning. In addition, the large bore allows patients in the
emergency department to be scanned quickly without removal or
adjustment of life-support equipment. Finally, the large bore makes
scanning more accessible for obese patients. "We are doing all
this, and we are also giving the power of the 16-slice scanner,"
Indiana University Hospital, a member of Clarian Health
Partners, is the site of the first U.S. installation of the
Brilliance CT 40-slice system from Royal Philips Electronics (Best,
The system, with 40-mm scanning coverage and
40-slice-per-rotation capability, is being used for imaging cardiac
patients and other studies of the chest and abdomen. It can scan
the lungs in 4 seconds and the abdomen and pelvis in 9 seconds.
Whole-body CT angiography (CTA) can be completed in 15 seconds,
while whole-body scan times are reduced to 35 seconds. According to
the company, the shorter breath-holds required with this system
increase patient comfort and decrease the potential for
"The unique power of the Philips Brilliance 40-slice system
allows us to image regions of the body faster, reducing patient
breath-holds, requiring less contrast media, and ensuring minimal
patient dose exposure," said Jonas Rydberg, MD, an Abdominal
Radiologist with Indiana Radiology Partners and an Associate
Professor of Radiology at the Indiana University School of
Medicine. "The 40-slice system, which acquires more thin slices, is
ideal for advanced applications, such as cardiology, that require
visualization of small structures, or trauma, where the speed of
the acquisition as well as fast reconstruction is vital," he
"We're thrilled to see the Brilliance CT 40-slice system
installed and in use at Indiana University Hospital," said
W. Green, Senior Vice President, General Manager, CT, for
Philips Medical Systems. "Our Brilliance family of scanners was
developed through extensive collaboration with customers like
Indiana University Hospital, whom we've partnered with for more
than 16 years. It is through partnerships like the one we share
with IU that systems can advance and maximize the clinical
utilization of CT."
Philips reports that it plans to install nine more systems
around the world in the next few months, with U.S. commercial
delivery beginning in the fall of this year.
New MRI liver contrast agent on the horizon
A new contrast agent, gadoxetic acid disodium (Primovist) from
Schering AG Group (Berlin, Germany), was recently approved for
marketing by the Swedish Health Authority. This new
gadolinium-based contrast medium was designed for the detection and
characterization of liver lesions by magnetic resonance imaging
(MRI), including liver tumors and metastases as well as other
malignant and benign lesions.
Chemically related to the company's Gd-DTPA (Magnevist), the new
agent is specifically taken up by hepatocytes, thereby delivering
parenchymal enhancement in healthy tissue. Cysts, metastases, and
most hepatocellular carcinomas have little or no hepatocyte
function and, therefore, remain unenhanced on imaging.
"Primovist is a new gadolinium-based contrast medium that offers
the possibility of simultaneously detecting, locating, and
distinguishing various types of liver lesions, thus providing a
powerful tool for radiologists that increases the diagnostic
confidence," said Michael Rook, Head of Diagnostics &
Radioparmaceuticals at Schering. "Furthermore, an examination with
Primovist-requiring only a single contrast media injection-improves
patient convenience and may have a positive impact on healthcare
Townsend named Distinguished Clinical Scientist of the
In other news, David W. Townsend, PhD, a Professor in the
Department of Medicine and Radiology, and Director of Cancer
Imaging and Tracer Development at the University of Tennessee
Cancer Institute, was named the Distinguished Clinical Scientist of
the Year by the Academy of Molecular Imaging (AMI). The award,
which was recently renamed the Peter Valk Award, was presented
during the AMI Annual Meeting in Orlando, March 27-31, 2004.
This award is given annually to the scientist who has made major
contributions to the development and enhancement of molecular
imaging and positron emission tomography (PET), as recognized by
his or her colleagues.
Dr. Townsend and Ronald Nutt, PhD, President and Chief Executive
Officer of CTI Molecular Imaging (Knoxville, TN), conceived the
concept of the combined PET/CT system and developed it with the
support of the engineering team at CPS Innovations, a unit of CTI.
Dr. Townsend and Dr. Nutt hold the patent for this technology.
As part of the Peter Valk Award, Townsend received a $20,000
cash award and presented the Distinguished Scientist Lecture, "From
3D PET to 3D PET/CT: What Did We Learn?" at the AMI meeting.
"On behalf of all of us at CTI, I want to congratulate David for
this fine honor that he has received," said Nutt when the selection
was announced. "The Distinguished Clinical Scientist of the Year
award is the most prestigious one that an AMI member can receive
from his peers. Having worked closely with David for many years as
a scientist and friend, I can say that he is extremely deserving of
this honor. Over his career, David has been an invaluable
contributor to the molecular imaging community and to CTI, and I am
delighted to see him recognized with this award."