As use of multislice computed tomography (CT) scanners becomes
more common, contrast protocols are being re-evaluated. Some
procedures, such as CT angiography, require faster injection rates
than had been used previously. This, in turn, has led to increased
concern regarding extravasation of contrast material. To address
these changing needs, imaging personnel are turning to increasingly
sophisticated power injectors.
Digital injector offers extravasation detection
(Westbury, NY) recently introduced the EmpowerCT injector, with
their proprietary Extrasvasation Detection Accessory (EDA)
technology (Figure 1).
The all-digital system allows flow rate adjustment at any time
during the procedure from 0.1 to 10 mL/sec, in 0.1-mL increments,
either remotely or at the injector head. The pressure can be set
from 20 to 300 pounds per square inch (psi) in increments of 1 psi.
The system can also be set for a specific pressure that it should
not exceed; the flow rate will be reduced or paused automatically
if that pressure is reached. A high-contrast EL display at the
injector head offers a real-time display of system parameters,
pressure, syringe volume, orientation, and EDA system status. The
injector head and controller display swivel independently, so the
system can be positioned on either side of the gantry.
Syringes can be filled manually or automatically, or prefilled
syringes may be used. Contrast may be placed in an automatic
All functions can be controlled at the workstation via a
touch-screen display. Up to 50 anatomically referenced
preprogrammed procedures can be stored in the system.
The company's EDA technology monitors for changes in skin
impedance indicative of a clinically significant extravasation. If
such changes are noted, the system automatically alerts the
operator and pauses the procedure. Although the injector head can
be rotated 270š, the system will not operate unless the injector
head is positioned properly to avoid the risk of air embolism. If a
problem arises during the procedure, spoken cues alert the operator
and the injection may be paused at either the injector head or at
the remote touch screen.
New syringe loader and MR infusion system from
(Indianola, PA) recently unveiled a new CT Syringe Loader that
allows contrast syringes to be filled outside the scan room.
The manufacturer reports that moving the filling process out of
the scanning area may reduce room preparation time and increase
throughput. In addition, with the continuous volume range of up to
200 mL, radiology personnel can control the amount of contrast
administered using weight-based dosing protocols.
The CT Syringe Loader can be mounted on a wall and is compatible
with the vendor's EnVision, Vistron, and MCT Plus vascular
injectors and syringes, as well as QFT, Spike, and bulk contrast
Medrad also recently announced that they have received 510(k)
clearance from the U.S. Food and Drug Administration (FDA) to begin
marketing their new Continuum MR Compatible Infusion System (Figure
2). With this system, patients can continue to receive intravenous
medications throughout the course of a magnetic resonance (MR)
The system can deliver up to three fluids via a single line and
incorporates an automatic free-flow protection feature. The device
is designed to be positioned close to the patient and uses minimal
priming volumes to reduce waste of medications.
The company, which debuted Continuum at the Radiological Society
of North America (RSNA) annual meeting in Chicago earlier this
month, expects the system to be available worldwide by early
New MR contrast agent detects malignancy in lymph
In other contrast imaging news, a recent study found that a new
MR contrast agent was able to distinguish malignant from normal
axillary lymph nodes accurately, one of the most important
prognostic factors, in breast cancer patients.
The ultrasmall superparamagnetic iron oxide contrast agent
Advanced Magnetics, Inc.
(Cambridge, MA) and
(Princeton, NJ) was tested in 18 patients with breast cancer who
were scheduled for surgery. MR imaging of the breast and axillary
lymph nodes was performed within 24 to 36 hours of the
administration of Combidex. The study results were then compared
with the histopathologic analysis. Use of the new agent resulted in
a sensitivity of 82%, a specificity of 100%, and a positive
predictive value of 100%.
"Treatment strategy in patients with breast cancer is dependent
not only on the extent of the primary tumor but also on axillary
lymph node staging," said H. Joseph Reiser, PhD, president and
chief executive officer of Cytogen Corp. "We believe that Combidex
can play an important role in the staging of metastatic disease in
a variety of cancers, especially through providing additional
information in the determination of lymph node status. This
information is key to allowing cancer patients and their physicians
to make more appropriate treatment decisions."
Combidex received an approvable letter for use in the diagnosis
of lymph node disease, subject to certain conditions, from the FDA
in June 2000.
"We are very encouraged by the results of this new study," said
Jerome Goldstein, chairman and chief executive officer of Advanced
Magnetics. "We continue to work with the FDA to resolve the
outstanding issues and remain hopeful that we will be successful in
AIUM issues statement warning against entertainment use
The American Institute of Ultrasound in Medicine (AIUM) recently
issued a statement reiterating its opposition to the use of
ultrasound for entertainment purposes. The statement was prompted
by the emergence of companies providing keepsake fetal ultrasound
videos to expectant mothers and their families.
The AIUM notes that "although there are no confirmed biological
effects from ultrasound at the present time, the possibility exists
that such biological effects may be identified in the future."
Therefore, they recommend that ultrasound only be used to provide
medical benefit to the patients.
A second concern raised by the society is that patients may
misinterpret the session as a medical examination. "Many pregnant
women expect that their ultrasound examination will identify
problems. This is not the case with entertainment sonograms," said
Alfred B. Kurtz, MD, AIUM president. "Entertainment sonograms do
not assess fetal well being. The personnel performing these studies
are often unskilled, while most 3D and 4D studies require
considerable expertise. Therefore, at times, the images created can
be disappointing or give a misleading appearance to the fetus. An
entertainment sonogram is a misuse of ultrasound technology and
should not be offered," he continued. "In addition, it should not
replace a medically indicated ultrasound examination."
The FDA concurs with the AIUM position, stating that "persons
who promote, sell, or lease ultrasound equipment for making
keepsake fetal videos should know that the FDA views this as an
unapproved use of a medical device. Those who subject individuals
to ultrasound exposure using a diagnostic ultrasound device (a
prescriptive device) without a physician's order may be in
violation of state or local laws or regulations regarding the use
of a prescriptive device." The entire FDA statement can be viewed