Chapter 20 Cardiac CT Imagingto also assess the prognostic value of increasing
CACP burden in population based samples. Genetic
studies measuring calcifi ed plaque with MDCT,
such as NHLBI’s Family Heart Study-SCAN are also
ongoing and will utilize the vascular calcium pheno-
type as a means of identifying genes related to ath-
erosclerosis and CVD.
Conclusions
The most promising use of cardiac CT at this time
is calcium scoring for risk-assessment of the asymp-
tomatic individual whereby elevated calcium scores
may lead to more vigorous application of both life-
style and/or pharmacologic therapies targeted to
lower cardiovascular risk and CT angiography to
rule out the presence of coronary stenoses in certain
subsets of symptomatic patients.
2008 Statement on noninvasive coronary
artery imaging: MR angiography and
multi-detector CT angiography [15]
This statement provides a discussion of technical
issues, applications, advantages, and limitations for
both MRA and CTA, and recommendations for
current and future uses.
Noninvasive coronary CTA and MRA represent
substantial advances that may ultimately be very
valuable for diagnosis of signifi cant coronary artery
disease. The chief advantages of coronary CTA com-
pared to MRA are wider availability, higher spatial
resolution, and more consistent, shorter examina-
tions with better patient compliance. Coronary
MRA has the advantages of lack of ionizing radia-
tion and lack of administration of iodinated contrast
material. Both tests are currently suboptimal in
patients with atrial fi brillation and other arrhyth-
mias, image quality may further be reduced by high
body mass.
Specifi c recommendations for use of
CTA and MRA
1 Neither coronary CTA nor MRA should be used
to “screen” for coronary artery disease.
2 No multi-vendor trial data are available for
MDCT coronary CTA or for current whole-heart
coronary MRA. Thus, the ability of these methods
to be widely applied other than at the reporting
research centers is unknown. Both multi-vendor
and additional multi-center validation of these
methods needs to be performed before widespread
acceptance in routine clinical practice.
3 The potential benefi t of coronary angiography by
CT or MR is likely to be greatest for symptomatic
patients at intermediate risk for coronary artery
disease after initial risk stratifi cation, including
patients with equivocal stress test results. Diagnostic
accuracy favors coronary CTA over MRA for these
patients. Concerns regarding radiation dose limit
coronary CTA in risk patients with very low pre-test
likelihood of coronary stenoses; patients with a high
pre-test likelihood of coronary stenoses are likely to
require intervention and require invasive catheter
angiography for defi nitive evaluation. Pronounced
coronary calcifi cation may negatively impact inter-
pretability and accuracy of coronary CTA.
4 Anomalous coronary artery evaluation can be
performed by either CTA or MRA; radiation protec-
tion concerns indicate MRA is preferred when it is
available.
5 Reporting of coronary CTA and MRA results
should describe any limitations as to the technical
quality of the examination and the size of the vessels,
descriptions of coronary anomalies, coronary steno-
sis and signifi cant noncardiac fi ndings within the
fi eld of view.
6 Continued research in CT and MR techniques is
encouraged to determine the potential of these non-
catheter based modalities to detect, characterize and
measure atherosclerotic plaque burden as well as its
change over time or as the result of therapy.ACCF/AHA 2007 clinical competence
statement on vascular imaging with
computed tomography and magnetic
resonance [16]
This statement is the fi rst American College of Car-
diology/American Heart Association (ACC)/AHA
document on clinical competence in vascular com-
puted tomography (CT) and magnetic resonance
imaging (MRI) and is designed to assist in the assess-
ment of physicians’ competence on a procedure-
specifi c basis. The minimum experience, knowledge
base, and technical skills necessary for the compe-
tent performance of vascular CT and MRI are
specifi ed.