Detection of ischemia with early myocardial
perfusion imaging: You see more if you watch
Riccardo Liga, MD,
and Alessia Gimelli, MD
Cardio-thoracic and Vascular Department, University Hospital of Pisa, Pisa, Italy
Fondazione Toscana, Gabriele Monasterio, Pisa, Italy
Received Mar 7, 2016; accepted Mar 7, 2016
See related article, pp. 1149–1156
Current medical guidelines for the management of
subjects with stable angina make the evaluation of the
presence and extent of inducible myocardial ischemia as
a mandatory step in the clinical workﬂow.
the precise quantiﬁcation of the myocardial ischemic
burden is widely believed as a necessary action also in
the management of patients with ascertained coronary
artery disease (CAD).
As a matter of fact, in the last
decades solid evidence has demonstrated that patients
with limited myocardial ischemia can be safely treated
conservatively (i.e., with medical therapy alone),
symptomatic subjects with relevant inducible ischemia
should be managed more aggressively and submitted, if
indicated, to coronary revascularization.
The evaluation of the presence of myocardial
ischemia can be performed either non-invasively, mostly
by means of provocative tests, or invasively, such as
with the assessment of fractional ﬂow reserve.
scenario, myocardial perfusion scintigraphy (MPS) by
means of single-photon emission computed tomography
(SPECT) allows a combined assessment of regional
myocardial blood ﬂow distribution coupled with left
ventricular (LV) functional parameters in a completely
offering the chance of
unmasking the presence of signiﬁcant CAD with a rel-
Accordingly, recent reports have
consistently demonstrated that the integrated evaluation
of myocardial perfusion and LV systolic and diastolic
functional measures may further increase the accuracy
of SPECT imaging in detecting CAD, possibly allowing
a more accurate risk stratiﬁcation of patients with sus-
pected or known disease.
However, despite these obvious clinical advantages,
MPS is characterized by two major technical drawbacks,
such as the cumulative radiation exposure
lengthiness of the imaging protocol,
limit its diffusion and make the clinician frequently
favor other non-invasive imaging modalities.
Recent advance in SPECT technology have effec-
tively addressed these major aspects of nuclear imaging,
offering the chance of further increasing its implemen-
tation. Above all, the introduction of dedicated cardiac
cameras, designed with cadmium-zinc-telluride (CZT)
detectors, probably represents one of the most relevant
novelties in the nuclear ﬁeld.
In fact, due to their increased photon sensitivity and
spatial resolution if compared to traditional SPECT
cameras, CZT devices allow obtaining an excellent
image quality despite a consistently reduced radio-
tracer’s injected dose.
Accordingly, different reports
have clearly demonstrated that the introduction of CZT
devices may allow to perform a stress myocardial per-
fusion scan with a radiation dose close to 1 mSv and a
low-dose stress/rest myocardial imaging protocol with a
cumulative dose of roughly 3 to 4 mSv.
the favorable technical speciﬁcs of CZT devices have
also allowed a consistent reduction of image acquisition
times, offering the chance to perform an excellently
tolerated, high-quality, test lasting 4 to 6 minutes.
Despite the astonishing reduction of the effective
acquisition times, the overall duration of a CZT imaging
protocol, as in the case of a traditional SPECT scan, is
mainly determined by the waiting intervals between the
injection of the radiopharmaceutical and the acquisition
In fact, those time periods between the
Reprint requests: Alessia Gimelli, MD, Fondazione Toscana Gabriele
Monasterio, Via Moruzzi 1, 56124 Pisa, Italy; email@example.com
J Nucl Cardiol 2017;24:1157–60.
Copyright Ó 2016 American Society of Nuclear Cardiology.