Computed tomographic angiography (CTA) is a valuable imaging modality for the evaluation of the vascular system. During the past decade, several studies have demonstrated that CTA has important advantages over the gold standard of conventional angiography, including increased safety, greater patient acceptance, lower cost, and reduced radiation exposure.1 Consequently, CTA has gained increasing attention as a potential minimally invasive diagnostic alternative to conventional angiography.
Computed tomographic angiography (CTA) is a valuable imaging
modality for the evaluation of the vascular system. During the past
decade, several studies have demonstrated that CTA has important
advantages over the gold standard of conventional angiography,
including increased safety, greater patient acceptance, lower cost,
and reduced radiation exposure.
Consequently, CTA has gained increasing attention as a potential
minimally invasive diagnostic alternative to conventional
The development of multislice spiral CT technology has
represented a significant advancement, particularly in the case of
CTA studies of mesenteric vasculature, where distal branches may
also be easily evaluated. First, multislice spiral CT allows for
acquisition times up to eight-fold faster than conventional
single-slice spiral CT scanners; this feature enables larger
anatomic coverage, and diminishes misregistration and respiratory
motion artifacts. Second, thin-slice collimation protocols can be
implemented routinely with greatly enhanced spatial resolution
along the longitudinal axis, which provides virtually isotropic 3D
voxels; consequently, image quality is improved with better
diagnostic capabilities. Third, optimization of contrast
enhancement is now possible due to more accurate timing and better
separation between the arterial and venous phases. However, in
order to entirely exploit the benefits of the use of multislice CT,
it is of paramount importance not only to optimize new study
protocols but also to improve image display. Three-dimensional
datasets are reconstructed and evaluated interactively on dedicated
workstations using axial and two-dimensional multiplanar images, as
well as more complex rendering techniques, such as maximum
intensity projections (MIP), surface-shaded displays (SSD), and
Multislice CTA technique
In our experience, images were obtained using a multislice
spiral CT scanner (Somatom Plus 4 Volume Zoom; Siemens Medical
Solutions, Erlangen, Germany) equipped with flying spot, adaptive
array matrix, and a gantry rotation time of 0.5 sec.
Before the study, patients received 800 mL of water as an oral
contrast agent in order to produce negative contrast in the stomach
and small bowel. A total of 140 mL of nonionic iodinated contrast
medium (Xenetix 350; Guerbet, Aulnay-Sous-Bois, France) were
infused intravenously at a rate of 4 to 5 mL/sec into a peripheral,
typically antecubital, vein. Following a bolus injection of 20 mL
of contrast medium, sequential dynamic slices were acquired at the
level of the superior mesenteric artery origin in order to evaluate
the optimal delay scanning time. Two spiral CT scans of the abdomen
and pelvis were obtained at the arterial phase (delay calculated on
bolus test injection) and portal venous phase (delay of 60 to 70
sec). Images were acquired using 1-mm slice collimation, 1-mm slice
thickness, 6 mm/sec table feed, 1.0-mm reconstruction interval, 120
mAs, and 120 kVp. Breath-hold time ranged between 30 and 35 sec,
depending on the size of the patient. Patients were instructed to
hyperventilate before scanning and to exhale slowly if they could
not suspend respiration for the entire examination time.
Since the use of a 1-mm slice collimation protocol produced a
considerable number of images (300 to 400 images per scan per
patient), we limited the image reconstruction interval to 1 mm,
with no image overlapping. In addition, since a lower flow rate
could have impaired optimal opacification of smaller arterial
vessels due to inadequate intravessel concentration of contrast
material, contrast medium was injected at a flow rate of at least 4
Once acquired, images were downloaded to an off-line dedicated
workstation (Kayak PC workstation; 2 parallel 700 MHz kernel
processors, 1024 Mb RAM memory; Hewlett Packard, Palo Alto, CA).
Image analysis was performed using Vitrea 2.2 (Vital Images,
Minneapolis, MN), a software package with volume-rendering
Selective vessel representation was obtained using different
rendering curves. A panoramic overview of the entire main abdominal
branches could be observed using a preset opacity curve showing
only the vascular surface. The evaluation of minor vessels (i.e.,
second, third, and more distal orders of collateral branches)
required the analysis of 3D data sets using interactive multiplanar
cut planes ("oblique trim") and by modulating the opacity of the
anatomical structures under evaluation and window/level parameters
in order to see vessels "through" abdominal organs. Image analysis
required direct operator interpretation at the workstation, where
2D axial and multiplanar reconstructions, and 3D images were
available simultaneously on a 21-inch monitor. A complete analysis
of arterial and venous vessels required a mean interpretation time
of 20 minutes.
Arterial vascular system
The superior mesenteric artery (SMA) is identified in its
entirety, including its origin and its major branches (Figure 1).
SMA usually arises <1.5 cm below the origin of the celiac trunk.
Major collateral branches are represented by 1) the inferior
pancreaticoduodenal artery, which has an oblique course,
anastomosing superiorly with the superior pancreaticoduodenal
artery, a branch of the gastroduodenal artery; 2) the middle and
right colic arteries, with the latter absent in up to 80% of normal
individuals, supplying blood to ascending colon; 3) the jejunal
branches, arising from the left side of the SMA; and 4) the
ileocolic artery and ileal branches arising from the right side of
the SMA, supplying blood to the ileum and cecum.
Anatomic variants such as an anomalous origin of the right
hepatic artery from the SMA can be depicted easily (Figure 2).
The inferior mesenteric artery (IMA), which arises from the
aorta approximately 7 cm below the origin of the SMA, can be
visualized together with the major branches (the left colic artery,
which has a straight superior course, supplying the transverse and
descending colon; the sigmoid arteries, two to four vessels
supplying the sigmoid colon and the superior hemorrhoidal artery,
terminal branch for the upper rectum) (Figure 3).
Venous vascular system
All major venous vessels (portal vein, splenic vein, superior
mesenteric vein, and inferior mesenteric vein) can be depicted
accurately, as are the collateral branches (Figure 4). The SMV is
usually a single trunk, receiving blood from the middle and right
colic veins, the ileocolic vein, the gastrocolic vein, and from
jejunal and ileal branches. The IMV receives blood from the left
colic vein, the sigmoid veins and the superior hemorrhoidal
vein.The major problem when evaluating the venous system was
discerning small arteries from veins, both of which were opacified
on delayed images. Correct image analysis required additional
interpretation time on the workstation.
Pathologic conditions where involvement of mesenteric vessels
has to be evaluated are represented mainly by pancreatic cancer and
Infiltration of SMA is a known contraindication to pancreatic
surgery. Simultaneous evaluation of axial and multiplanar
reformatted planes has been demonstrated to be useful for assessing
vascular invasion and in particular sagittal planes (Figure 5). It
can also provide excellent evaluation of the posterior fat plane
between the SMA and the abdominal aorta, which is especially useful
to rule out vascular encasement. A more precise evaluation of the
SMV and the portal vein is also extremely important, since a vessel
infiltration <2 cm is considered a criterion for performing
pancreatic surgery with a vascular graft. Again, multiplanar
reformatted images (along coronal or coronal-oblique planes),
provide excellent evaluation of possible vascular infiltration.
In the case of mesenteric ischemia, multislice spiral CTA may
provide all necessary diagnostic information before planning
adequate treatment. Multislice spiral CTA can demonstrate the
underlying cause if the ischemia, which might be represented by
narrowing or occlusion of the SMA (due to either atherosclerotic
plaque or thrombus or neoplastic vascular infiltration), or by
thrombosis or neoplastic encasement of SMV.
Finally, multislice spiral CTA might have a role in the
assessment of vascular changes in cases of inflammatory bowel
disease, small bowel tumors (i.e., carcinoid, lymphoma), and, less
frequently, pathologic conditions (i.e., metastases, sclerosing
With its greatly enhanced image resolution, multislice CTA seems
able to overcome the technical challenge of depicting small
mesenteric vessels. It provides a detailed anatomical view similar
to that of conventional angiography but with the possibility of
examination from innumerable viewing angles. Technical requirements
include interactive evaluation on a workstation using dedicated
reconstruction algorithms. Volume-rendering is the most suitable
reconstruction technique, due to its ability to display the 3D
spatial relationships among vessels and surrounding organs.
Widespread applications for these techniques can be expected in the
near future with the greater availability of multislice CT
equipment, improvement in workstation design and performance, and
specific education of radiologists in the use of 3D software. A
cost-benefit analysis must be performed in order to better evaluate
the impact of this new imaging modality on patient outcomes.
Although further studies are necessary to rigorously compare the
results of multislice CTA with conventional angiography in terms of
diagnostic accuracy, an increased use of this imaging modality in
the study of mesenteric vessels can be anticipated, with multislice
CTA progressively obviating the need for diagnostic conventional
1. Rubin GD, Shiau MA, Schmidt AJ, et al. Computed tomographic
angiography: Historical perspective and new state-of-the-art using
multi detector-row helical computed tomography.
J Comput Assist Tomogr
2. Johnson PT, Heath DG, Kuszyk BS, Fishman EK. CT angiography
with volume rendering: Advantages and applications in splanchnic
3. Laghi A, Iannaccone R, Catalano C, Passariello R. Multislice
spiral computed tomography angiography of mesenteric arteries.
4. Horton KM, Fishman EK. Volume-rendered 3D CT of the
mesenteric vasculature: Normal anatomy, anatomic variants and
Optimizing Multislice CT for Imaging with the Goal of 3D
William J. Davros, PhD, ABMP(D)
The advent of multislice CT (MSCT) has introduced in a new era
in medical imaging. High-quality cross-sectional images can be
gathered faster than ever before without sacrificing quality. The
new MSCT units are more complex than previously offered units but
also hold out the promise to be more flexible. It has also opened
the possibility of more accurate diagnosis by radiologists,
CT-based screening programs, integrated CT radiotherapy treatment
planning, and three-dimensional (3D) volume-rendered processing for
the purpose of pre-operative planning. This article will focus on
optimizing MSCT image data collection and reconstruction for 3D
Optimizing MSCT can be divided into two categories: optimization
of scanning parameters and optimization of image reconstruction
parameters. Scan parameters are set prior to the initiation of raw
data collection and can be preprogrammed by the vendor or stored as
site-specific protocols. Regardless of the selection process, they
are a major determining factor in the quality of a postprocessed
product. Reconstruction parameters can be set before or after
scanning is completed. These parameters control the look of the
final image and, therefore, also play an integral role in the
quality of the final product.
Parameters available for optimization are X-ray tube potential
(kV), the X-ray tube current (mA), the scan time per gantry
revolution (s), and the X-ray detector configuration. The tube
potential is the most important parameter in controlling the amount
of image contrast. Lower X-ray tube potential will augment image
contrast, especially when iodinated contrast medium is used. This
is due to the fact that the absorption of X-rays is greater at
lower photon incident energies. In practical terms, 80 kV will
produce superior image contrast than 120 kV, and 120kV will produce
greater image contrast than 140 kV. Most facilities use 120 kV
because it is a good compromise between image contrast and
penetrability of the photons. The X-ray tube current-time product
(mAs) is proportional to the number of photons. When more photons
are used, lower image noise will result. Image noise hampers
postprocessing by making the job of discriminating between two
structures whose CT numbers are close together more difficult.
Detector configuration is the scan parameter that, in part,
determines the final image thickness. When scanning with the
thought of postprocessing, it is recommended to choose a detector
configuration that will permit very thin image reconstruction.
These scanners will not permit image thickness to be less than the
smallest z-axis dimension of the detector configuration chosen. For
example, if a 1-mm image thickness is desired, the user might
select the 0.5 mm * 2 or 4 * 1 mm configurations, but not the 4 *
2.5 mm configuration.
Once raw data has been gathered by scanning, images need to be
reconstructed. The parameters available for image reconstruction
are image thickness, image-to-image spacing, reconstructed
field-of-view (FOV), and reconstruction kernel.
* Image thickness is a measure of the z-axis distance over which
scan projections are combined to produce a two-dimensional image.
Thinner image thickness usually produces more pleasing
postprocessed work than do thicker images.
* Image-to-image spacing is a measure of the z-axis distance
between image centers. Overlapped images exist if the
image-to-image spacing is less than the image thickness. Contiguous
images exist if the image-to-image spacing is equal to the image
thickness. If the image-to-image spacing is greater than the image
thickness gaps between images exist. Optimal postprocessing is
achieved when the image-to-image spacing is about one-half to
one-third of the image thickness. For example, if the image
thickness is 7 mm, the image-to-image spacing should be 2.5 to 3.5
mm. For the sake of simplicity many sites use integer values for
image-to-image spacing by rounding, but never using a value larger
than one-half of the image thickness.
* The reconstructed FOV is the parameter that determines the
pixel dimension in the axial imaging plane. The pixel dimension is
equal to the FOV in millimeters divided by 512. For example, an
abdominal image may have been reconstructed with a 330-mm FOV, in
which case the pixel size is 0.625 * 0.625 mm. In general, 3D
postprocessed images have a greater potential to show fine
structures when the pixel size is small. This leads to a
recommendation that the FOV be as small as possible consistent with
viewing all necessary anatomy.
* The reconstruction kernel is a mathematical device that is
used to control how sharp edges will be displayed in the final
image set, as it controls how much image noise will be displayed.
Smoother kernels used in soft-tissue imaging display less noise and
thus the images have a soft look to them. The main advantage to
this type of image is the ability to see low-contrast lesions, such
as a liver tumor surrounded by normal liver tissue, in a
non-contrast scan. Detail or bone kernels display sharp edges with
high fidelity but display a great deal of noise. In this type of
imaging, the noise is less of a problem in that the scan was
presumably done to image fine detail such as bone fractures or
high-resolution lung imaging. Postprocessed images tend to look
best when the kernel is at the smoother end of the available
choices. Surface-shaded models and volume-rendered models have a
more pleasing surface appearance because the inherent low noise in
the 2D images translates to less pitted surfaces on 3D models.
Postprocessed imagery is a powerful tool in the arsenal of
medical imaging. It permits surgeons to see anatomy in a familiar
frame of reference. Optimizing multislice CT for postprocessing is
the key to unlocking the potential of postprocessed imagery.
Indications and Utilization of Abdominal CT in the
Max P. Rosen, MD, MPH
The advent of multislice CT (MSCT) scanners has lead to an
expansion of the application of CT for suspected abdominal
pathology. One area in which it has had its greatest impact is in
the Emergency Department (ED). Our experience at a level 1, adult,
academic trauma center shows the number of abdominal CT scans
performed has increased from 24.56 per 1000 ED visits in 1999 to
28.34 per 1000 ED visits in 2000. The "top 5" indications for
abdominal CT in our ED are: 1) suspected appendicitis (17%), 2)
renal colic (15%), 3) suspected abscess (12%), 4) suspected
diverticulitis (10%), and 5) suspected small bowel obstruction
(7%). Between 1997 and 2000, the proportion of abdominal CT scans
performed in our ED for suspected bowel pathology has increased
from 37% to 50%.
The proliferation of CT for suspected bowel pathology is likely
due to a combination of the publication of several studies
demonstrating the sensitivity and specificity of CT for diagnosing
the above abdominal conditions. A Medline search of the terms
"appendicitis" and "CT scan" for 1990 yielded only 8 articles. This
increased to 25 in 1995, and 79 in 2000. We have found that
advances in imaging technology published in the literature
translate into an increase in clinical requests for an imaging
study within 1 year of the publication.
In addition, the maturation of CT technology has paralleled the
penetration of managed care. In the past, many patients with
abdominal pain would have been admitted to the hospital for
observation. However, managed care has placed a premium on avoiding
hospital admission. As one of the major functions of the ED is to
triage patients between hospital admission and outpatient
management, any technology that enhances the triage ability of ED
physicians is especially valuable in the managed care
We recently studied our experience with 536 consecutive patients
with non-traumatic abdominal pain who underwent a CT scan in the
ED. Prior to ordering the CT, each physician was asked to identify
his/her planned management. We then followed each patient and
studied his/her actual management. Prior to performing the CT, 402
of 536 (75%) would have been admitted to the hospital. However,
following CT, only 312 of 536 (58%) were actually admitted. The net
effect of performing CT was to obviate the need for hospital
admission in 90 of 536 (17%) of patients. Prior to CT, 67 of 536
(13%) of patients were thought to need immediate surgery. Only 25
of 536 (4.6%) actually underwent surgery. Of the 67 patients
thought to need surgery, only 25 (37%) actually required immediate
surgery. Among patients with the four most common pre-CT diagnoses
(appendicitis, renal colic, abscess, and diverticulitis), CT had
the greatest impact on hospital admission rates (28% reduction) and
surgical management (40% altered management) for patients with
The apparent reliance on CT to evaluate patients with suspected
abdominal pain in the ED likely reflects the high sensitivity and
specificity of CT and the elusive nature of clinical diagnostic
certainty in assessing patients with abdominal pain (Figure 1).
Among a group of 57 patients who presented to our ED with abdominal
pain, we found that CT had a sensitivity and specificity of 96% and
However, our approach to evaluating patients with abdominal pain
includes an initial assessment by an intern or resident, who are
often uncertain of their clinical diagnosis. For example, when
asked to rate their level of certainty in their clinical (pre-CT
diagnosis), the mean level of certainty expressed by our interns
and residents was only 2.4 on a 5-point scale (1 = least certain, 5
= most certain).
This lack of certainty in their clinical diagnosis is supported
by the findings of another study conducted at our hospital in which
we reviewed 100 consecutive CT scans performed for suspected
Among these 100 patients presenting with right lower quadrant pain,
CT correctly identified 23 of 24 (95.8%) patients with surgically
proven appendicitis. However, CT also identified a varied
constellation of other pelvic conditions that cause right lower
quadrant pain including: uterine/adnexal pathology (N = 16),
diverticular disease (N = 9), inflammatory bowel disease (N =3 ),
urinary tract disease (N = 2), and mesenteric adenitis (N = 2). In
addition, CT identified pathology above the level of the iliac
crest in an additional 7 patients. In the days prior to
cross-sectional imaging, it is safe to say that the vast majority
of these patients would have required hospital admission and either
would been observed as their physician waited for the etiology of
the abdominal pain to "declare" itself, or would have undergone to
We have found that the use of CT to evaluate patients with
suspected abdominal pain on our ED continues to increase. This is
likely due to the rapid evolution of MSCT technology, the high
sensitivity and specificity of CT for accurately identifying the
etiology of abdominal pathology, and the need for rapid triage in
the ED under managed care.
1. Rosen MP, Sands DZ, Longmaid HE, et al. Impact of abdominal
CT on the management of patients presenting to the emergency
department with acute abdominal pain.
AJR Am J Roentgenol.
2. Kamel IR, Goldberg SN, Keogan MT, et al. Right lower quadrant
pain and suspected appendicitis: Non-focused appendiceal CTReview
of 100 cases.
New Screening Technologies
Judith V. Douglas, MS, MPH
The scientific community is now questioning the assumption that
early detection and treatment hold value in all instances.
Researchers are reviewing evidence from studies of screening for
different diseases, asking whether tests, even when relatively
inexpensive and non-invasive, save lives and in fact "do no harm."
In addition to the furor surrounding mammography and the PSA test,
questions are arising regarding other procedures used to diagnose
cancer and other diseases.
Some procedures are relatively untested, although market forces
are clearly involved. In 2001, for example, one manufacturer of
electronic beam computerized tomography (EBCT) used to diagnose
heart disease reported sales of $19.3 million for one quarter
The same year, a newly opened "virtual physical" center in
Baltimore reported that its first 57 scans generated 27
recommendations for patients to see a doctor for follow-up,
including 12 cardiology referrals.
To date, however, there is slim support among the medical
establishment for full-body scans. Offered by freestanding
entrepreneurial centers to those willing and able to pay out of
their own pockets, virtual physicals remain outside routine
Since colon cancer is the second leading cancer killer in the
United States and is 90% preventable, virtual colonoscopy may
become part of routine care. Although traditional colonoscopy has
widespread support among medical professionals as screening for
patients aged >=50, many patients avoid it as unpleasant. Less
invasive, virtual colonoscopy requires less rigorous preparation, a
shorter examination, and no anesthesia. Costs are debatable, some
studies cite the virtual procedure as less expensive ($500 to $1000
compared with $1000 to $2000),
while others suggest that the additional time needed for analysis
makes it more expensive.
Neither covered by many insurers nor generally available, virtual
colonoscopy has other drawbacks. In a study of 300 patients
examined with both methods, the virtual procedure missed 30% of the
polyps (more smaller ones) found using the traditional video.
Approximately 10% of those screened virtually will need to undergo
the conventional procedure to remove the polyps.
Nonetheless, until totally noninvasive molecular tests are
available, virtual colonoscopy may offer reluctant patients an
Another test yet to find its way into standard care screens
smokers and ex-smokers for lung cancer.
Lung cancer is the leading cause of cancer deaths in the United
States, with the same 5-year survival rate it had over 30 years
ago. The screening uses powerful spiral CT scanners to detect
tumors that are much smaller than those found with conventional
chest X-rays. According to one study, 23% of those tested using
spiral CT had suspicious nodules, but only 2.7% were in fact
; almost all of these were in Stage 1 and had not spread.
Chest x-rays found suspicious nodules in only 7%, 0.7% of them
cancerous; half of these were Stage 1 and the other half were more
advanced. Such findings raise more questions than answers. Dr.
director of the Office of Disease Prevention at the National
Institutes of Health, cites a study in Japan in which spiral CT
found similar number of cancers in nonsmokers as in smokers, yet
the latter are ten times more likely to die of lung cancer. In his
opinion, the new test, like the old one, is "finding cancers that
are not dangerous."
Early detection of cancer is an uncertain enterprise. Dr.
Stephen Swensen, chairman of radiology at the Mayo Clinic, screened
1520 smokers and former smokers with spiral CT. Of more than 2800
suspicious nodules, 37 were found to be malignant tumors. In some
cases, the testing entailed chest surgery, with a 4% chance of
death. Although patients undergoing spiral CT "assume that this
could save their lives," said Dr. Swensen, "That is absolutely,
Dr. Steven Goodman, associate professor of pediatrics and
epidemiology at the Johns Hopkins University School of Medicine,
notes that screening is different from any other medical program.
"We bring it to healthy people, and those who test positive become
sick people, the subjects of medical intervention. We need to be
1. Farella C. Is popular heart scan sound or scam?
Published October 9, 2001. Available at
www.virtualphysical.com/nursingspectrum1000901.html. Accessed April
2. Salganik MW. Full-body scanning seeks a new image.
April 13, 2001. Available at
www.virtualphysical.com/BaltSun010413.html. Accessed April 10,
3. Lahn J. Colonoscopy could go virtual.
. January 2000. Available at
February 11, 2002.
4. Boyd K. Virtual colonoscopy effective for colon cancer
screening. UCSF Medical Center Health & Medical News press
release dated May 30, 2002. Available at
www.ucsfhealth.org/news.org/hm_news/30may01.htm. Accessed June
5. Yee Y, Akerkar GA, Yung RK. Colorectal neoplasia: Performance
characteristics of CT colonography for detection in 300 patients.
6. Cropper CM. Colon cancer: An easier diagnosis.
Business Week Online
. October 15, 2001. Available at
www.virtualphysical.com/bwonline101501.html. Accessed April 10,
7. Kolata G. Lung cancer test is much in demand, but benefit is
New York Times
. June 21, 2000. Available via the New York Times Premium Archive
at www.nytimes.com. Accessed March 14, 2002.
8. Henschke CI, McCauley DI, Yankelevi DF, et al. Early Lung
Cancer Action Project: Overall design and findings from baseline
9. Kolata G. Test proves fruitless, fueling new debate on cancer
New York Times.
April 9, 2002:D1,D4.
10. Kolata G. Questions grow over usefulness of some routine
New York Times.
December 30, 2001. Available via The New York Times Premium Archive
at www.nytimes.com. Accessed March 14, 2002.
Dr. Silverman is a Professor of Radiology, the Gerald D. Dodd,
Jr. Distinguished Chair of the Diagnostic Imaging Section of Body
Imaging, Section of Body Imaging University of Texas M.D. Anderson
Cancer Center Houston, TX. Dr. Davros is Section Head of Medical
Physics, Department of Diagnostic Radiology. Cleveland Clinic
Foundation, Cleveland OH. Dr. Rosen is Director of Radiology, Beth
Israel Deaconess Medical CenterMedical Care Center North, Chelsea,
MA. Ms. Douglas is an adjunct faculty member at the Johns Hopkins
University School of Nursing, Baltimore, MD.
In compliance with the Essentials and Standards of the ACCME,
the authors of this CME tutorial are required to disclose any
significant financial or other relationships they may have with the
manufacturer(s) of any commercial product(s) or provider(s) of any
commercial service(s) discussed in this program.
Dr. Laghi, Dr. Davros, Dr. Rosen, and Ms. Douglas have disclosed
that they have no such relationships. Dr. Silverman discloses a
relationship with Amersham Health through their sponsorship of this
newsletter series, for which he serves as editor-in-chief.
is published by Anderson Publishing, Ltd., 1301 West Park Ave.,
Ocean, NJ 07712; (732) 695-0600. O. Oliver Anderson, Publisher,
Elizabeth A. McDonald, Managing Editor; Felice Ponger, Art
Sponsored by a grant from Amersham Health. The views and
opinions expressed in this publication are those of the authors and
do not necessarily reflect those of
the publisher or sponsor. Full and complete prescribing information
should be reviewed regarding any product mentioned prior to
2002 Anderson Publishing, Ltd.