(2022) 22:32
Li et al. BMC Medical Imaging
https://doi.org/10.1186/s12880-022-00761-1
Open Access
RESEARCH
Clinical value of resting cardiac dual-energy
CT in patients suspected of coronary artery
disease
Wenhuan Li1*, Fangfang Yu1, Mingxi Liu1 and Chengxi Yan2
Abstract
Background: Rest/stress myocardial CT perfusion (CTP) has high diagnostic value for coronary artery disease (CAD),
but the additional value of resting CTP especially dual-energy CTP (DE-CTP) beyond coronary CT angiography (CCTA)
in chest pain triage remains unclear. We aimed to evaluate the diagnostic accuracy of resting myocardial DE-CTP, and
additional value in detecting CAD beyond CCTA (obstructive stenosis: ≥ 50%) in patients suspected of CAD.
Methods: In this prespecified subanalysis of 54 patients, we included patients suspected of CAD referred to invasive
coronary angiography (ICA). Diagnostic accuracy of resting myocardial DE-CTP in detecting myocardial perfusion
defects was assessed using resting 13N-ammonia positron emission tomography (PET) as the gold standard. Diagnostic accuracy of cardiac dual-energy CT in detecting flow-limiting stenoses (justifying revascularization) by CCTA
combined with resting myocardial DE-CTP, using ICA plus resting 13N-ammonia PET as the gold standard. The CCTA
and DE-CTP datasets derived from a single-phase scan performed with dual-energy mode.
Results: For detecting myocardial perfusion defects, DE-CTP demonstrated high diagnostic accuracy with a sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of 95.52%, 85.93%, and 0.907 on a
per-segment basis. For detecting flow-limiting stenoses by CCTA alone, sensitivity, specificity, and AUC were 100%,
56.47%, and 0.777 respectively on a per-vessel basis. For detecting flow-limiting stenoses by CCTA combined with
resting myocardial DE-CTP, sensitivity, specificity, and AUC were 96.10%, 95.29% and 0.956 respectively on a per-vessel
basis. Additionally, CCTA combined with resting myocardial DE-CTP detected five patients (9%) with no obstructive
stenosis but with myocardial perfusion defects confirmed by ICA plus 13N-ammonia PET.
Conclusions: Resting cardiac DE-CTP demonstrates a high diagnostic accuracy in detecting myocardial perfusion
defects and provides an additional clinical value by reducing rates of false-positive and false-negative patients beyond
CCTA in patients suspected of CAD.
Keywords: Dual-energy CT, Myocardial perfusion, Coronary artery disease, Invasive coronary angiography, Positron
emission tomography
*Correspondence: liduanbenben@163.com
1
Department of Radiology, Beijing Chao-Yang Hospital, Capital
Medical University, 8 Gongren Tiyuchang Nanlu, Chaoyang District,
Beijing 100020, China
Full list of author information is available at the end of the article
Background
A comprehensive assessment of coronary artery disease
(CAD) requires not only morphologic information about
coronary artery stenosis but also functional evaluation
about haemodynamic significance of coronary artery
lesions [1–3]. Although a negative coronary CT angiography (CCTA) result provides excellent negative predictive
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Li et al. BMC Medical Imaging
(2022) 22:32
value to exclude obstructive CAD (stenosis: ≥ 50%), the
sole reliance on the presence of obstructive stenosis is
less robust to identify CAD [4–6]. This can be caused by
pathophysiologic explanations such as luminal thrombosis followed by recanalization, endothelial dysfunction
with decreased coronary flow reserve, and vasospasm [7].
It can also be caused by technical factors such as inadequate resolution with heavily calcified plaque, branch
vessel disease and image degradation during arrhythmia [8]. In any of these situations, myocardial perfusion
assessment can provide complementary functional information in improving detecting CAD in patients presenting with chest pain.
Recent single-center studies have shown good diagnostic performance of rest/stress myocardial CT perfusion (CTP) in detecting myocardial ischemia and infarct
in both the acute and stable outpatient groups [9]. But
the additional value of resting CTP especially dualenergy CTP (DE-CTP) beyond CCTA in chest pain triage remains unclear. Therefore, the aim of our study was
to evaluate the diagnostic accuracy of resting myocardial
DE-CTP, and additional value in detecting CAD beyond
CCTA in patients suspected of CAD presenting with
chest pain.
Methods
Our study was approved by the institutional ethics committee, and the written informed consent was obtained
from each patient. The study design was retrospective. Patients were recruited from an existing prospective study database consisting of consecutive patients
suspected of CAD presenting with acute or stable chest
pain to our hospital between March 2017 and November
2019. Patients who underwent cardiac dual-energy CT
scan, resting 13N-ammonia positron emission tomography (PET) and invasive coronary angiography (ICA)
within one week time interval between examinations
were enrolled. Patients were excluded if they had history
of myocardial infarction, cardiomyopathy, myocarditis,
contraindication to iodinated contrast agent, atrial fibrillation or renal dysfunction (estimated glomerular filtration rate < 60 ml/min/1.73 m2).
PET data acquisition and image analyses
PET examinations were performed at rest on ECAT
EXACT (CTI-Siemens, Knoxville, Tennessee, USA),
which provide 47 tomographic slices. Patients abstained
from food at least 6 h before the PET examination. Resting PET myocardial blood flow imaging was acquired
15 min after 13N-ammonia (555 MBq) was injected.
Tomographic images were reconstructed by the filtered
back projection method. Typical horizontal long axis,
vertical long axis, and short axis tomographic views of
Page 2 of 8
the left ventricle were obtained by an image processing
workstation for image analysis.
PET images were visually analyzed by 2 experienced
readers who were blinded to the patient information.
Horizontal long axis, vertical long axis, and short axis
images were assessed on a per-segment and -territory
basis using American Heart Association 17-segment
model [10]. The disagreement of diagnosis between 2
readers was settled by a consensus reading. The disagreement of diagnosis between 2 readers was settled by a
consensus reading.
Invasive coronary angiography
ICA was performed by standard catheterization in
accordance with the American College of Cardiology
Guidelines for Coronary Angiography [11]. ICA was
evaluated by quantitative coronary angiography (QCA;
QuantCor QCA, Siemens AG Healthcare) by 2 cardiologists in consensus who were blinded to the dual-energy
CT and PET results. All coronary artery stenosis was
graded at least 2 orthogonal views and measurement
was performed in the projection that showed the highest degree of stenosis. A mismatch between PET and ICA
was defined as a positive PET scan with a negative ICA
for significant coronary stenoses or a negative PET scan
with a positive ICA for significant coronary stenoses.
Dual‑energy CT scan protocol
All CT examinations were performed at rest state
using dual-energy mode of a 128-slice dual-source CT
(DSCT; SOMATOM Definition Flash, Siemens Healthcare, Forchheim, Germany). Before the examination, the
heart rate of each patient was measured. If the resting
heart rate was higher than 65 beats per minute (bpm)
and no contraindication to the use of β-blockers, metoprolol tartrate (Beloc, AstraZeneca, Wedel, Germany)
was administered intravenously in fractions of 5–25 mg
before the examination. Scanning parameters were as follows: 2 × 64 × 0.6 mm acquisition collimation with z-flying focal spot technique, and heart rate adaptive pitch
of 0.17–0.35. Automated tube current modulation (Care
Dose 4D, Siemens Healthcare) was used. One tube of
DSCT system was operated with 165 reference mAs per
rotation at 100 kV, and the second tube was automatically
operated with 140 reference mAs per rotation at 140 kV.
All scans were performed in cranio-caudal direction of
supine position during a mid-inspiratory breath-hold.
The scanning range started from above the origin of the
coronary arteries to below the dome of the diaphragm.
Contrast agent was injected by a dual-syringe injector
(Stellant D, Medrad, Indianola, USA) using an 18-gauge
intravenous needle placed in the right antecubital vein. A
triphasic injection protocol was used [12]. First, 50 mL of
Li et al. BMC Medical Imaging
(2022) 22:32
pure contrast media (Iopromide, Ultravist 370, 370 mg/
mL, Bayer-Schering Pharma, Berlin, Germany) was
administered. Thereafter, 30 mL of 70%/30% saline/contrast medium mixture was administered. Finally, 30 mL
of saline was administered. The injection rate for all
phases was 5 mL/s. Contrast agent application was controlled by a bolus tracking technique. A region of interest
was placed in the aortic root, and image acquisition automatically started 7 s after the signal attenuation reached
the predefined threshold of 100 Hounsfield units (HU).
Dual‑energy CT post‑processing
CCTA and resting myocardial DE-CTP were reconstructed from data of single arterial phase dual-energy
CT scanning. The CCTA images were reconstructed with
0.75 mm slice thickness, 0.5 mm increment, 75 ms temporal resolution, and B26f kernel. All images were reconstructed by the same person to reduce bias. Then the
reconstructed CCTA images were transferred to multimodality work-place (MMWP, Siemens Healthcare,
Forchheim, Germany) and loaded into the Circulation
application for further analysis.
The DE-CTP images were reconstructed with 1.5 mm
slice thickness, 1.0 mm increment, 280 ms temporal resolution, and a dedicated dual-energy convolution kernel
(D30f ). By default, raw data were automatically reconstructed into low-kilovoltage (100 kV) images and highkilovoltage (140 kV) images. Then the 100 kV and 140 kV
images were transferred to MMWP and loaded into dualenergy Heart PBV (Siemens Healthcare) to calculate the
iodine distribution maps, with color-coded of “Hot Body
8 bit”. A normal myocardial area was chosen to normalize
the iodine distribution maps [13].
Dual‑energy CT image analyses
All dual-energy CT images were assessed on MMWP and
patient information was removed. Images were assessed
independently by two cardiac radiologists who were
blinded to the patient information and disagreements
were resolved by consensus. We performed separate
readings of resting DE-CTP and CCTA. Readings were
spaced at 2-week intervals to minimize recall bias.
The DE-CTP images were visually analyzed on a persegment -territory and -patient basis according to the
American Heart Association 17-segment model [10]. In
color-coded iodine distribution maps, light orange indicated the highest iodine content and gray indicated the
absence of iodine. For DE-CTP, the normal myocardium
was defined as homogeneous light orange without any
gray area; myocardial perfusion defect was defined as
distinct grey area compared with normal surrounding
myocardium. Diagnostic accuracy of resting myocardial
DE-CTP in detecting myocardial perfusion defects was
Page 3 of 8
assessed using resting 13N-ammonia PET as the gold
standard.
CCTA images were analyzed for coronary obstructive
stenosis ≥ 50% for each vessel (left anterior descending
coronary artery, right coronary artery, and left circumflex coronary artery) based on axial source images, crosssectional views, multiplanar reformations, curved planar
reformations and thin-slab maximum intensity projection images. The association between coronary artery
distribution and myocardial segments was analyzed on
the basis of the AHA recommendations [10]. In view of
the possibility of the mismatch between vessels and segments based on the AHA model, curved planar reconstruction or three-dimensional CT renderings was used
to establish one to one relationship between each myocardial segment and the coronary artery that supplies it,
providing accurate registration between them (Fig. 1D).
Diagnostic accuracy of cardiac dual-energy CT in detecting flow-limiting stenoses was assessed by CCTA combined with resting myocardial DE-CTP, using ICA plus
resting 13N-ammonia PET as the gold standard.
Statistical analysis
Statistical analysis was performed using SAS version
9.1 (SAS Institute Inc., Cary, North Carolina), and the
threshold of significance was P value < 0.05. Quantitative variables were expressed as mean value ± standard
deviation. The diagnostic performance was calculated,
including sensitivity, specificity, positive predictive
value, negative predictive value, and accuracy with 95%
confidence intervals. Additionally, the receiver operating characteristic (ROC) curve analysis was performed.
The area under the ROC curves (AUCs) were compared
by the DeLong method. Kappa tests were used to assess
intra- and interobserver agreement in CCTA and resting myocardial DE-CTP analysis in 10 randomly selected
patients. The Kappa value was interpreted as follows:
0–0.20 poor agreement, 0.21–0.40 fair agreement, 0.41–
0.60 moderate agreement, 0.61–0.8 good agreement,
and > 0.81 excellent agreement.
Results
The characteristics of the study analytic population are summarized in Table 1 (n = 54). The radiation effective dose was 2.7 ± 0.5 mSv (dose-length
product × 0.014 mSv/mGy·cm) for of dual-energy CT
scanning. For the cardiac PET examination, the radiation dose from 15 mCi (555 MBq) of 13N-ammonia is
1.11 mSv. Figure 1 showed an example of mismatch
between coronary stenosis severity and resting DE-CTP.
Figure 2 showed an example of match between coronary
stenosis severity and resting DE-CTP.
Li et al. BMC Medical Imaging
(2022) 22:32
Page 4 of 8
Fig. 1 Mismatch between coronary stenosis severity and resting DE-CTP. A Curved multiplanar reconstruction CCTA reveals no coronary
artery stenosis along left anterior descending (LAD). But resting DE-CTP analysis multiplanar reformatting demonstrates a rest perfusion
defect in short-axis (B) and horizontal long-axis views (C), which confirmed by 13N-ammonia PET (E, F). In this 48-year-old female presenting
with chest pain, serial troponin was mildly elevated leading to invasive coronary angiography (G), which revealed mild narrowing of the left
anterior descending that resolved with intracoronary nitroglycerin, consistent with coronary vasospasm. D Fusion image of three-dimensional
CCTA and two-dimensional DE-CTP shows the relationship between the perfusion defects area and corresponding supplying artery (LAD).
DE-CTP = dual-energy CT perfusion; CCTA = coronary CT angiography; PET = positron emission tomography; LAD = left anterior artery
Table 1 Characteristics of the study population (n = 54 patients)
Characteristics
Value
Age (years) [mean ± SD; range]
60 ± 10 [39,76]
Sex [male/female]
32/22
BMI [kg/m2; mean ± SD; range]
25 ± 4 [21,30]
Mean heart rate during DECT (bpm) [mean ± SD; range]
59 ± 9 [45,78]
Hypertension (%)
18(33%)
Hypercholesterolemia (%)
12(22%)
Diabetes mellitus (%)
12(22%)
Current or prior cigarette smoking (%)
14(26%)
Values are n (%)
SD, standard deviations; BMI, body mass index; bpm, beats per minute
Myocardial dual‑energy CT perfusion in detecting
myocardial perfusion defects
A total number of 918 myocardial segments in 162 territories in 54 patients were analyzed. Diagnostic accuracy,
sensitivity, specificity, positive predictive value (PPV),
negative predictive value (NPV), and AUC of DE-CTP
in detecting myocardial perfusion defects were 89.43%,
95.52%, 85.93%, 79.60%, 97.09%, and 0.907 respectively
on per-segment basis; 91.98%, 97.56%, 86.25%, 87.91%,
97.18%, and 0.919 respectively on a per-territory basis;
94.44%, 100%, 82.35%, 92.50%, 100%, and 0.912 respectively on a per-patient basis (Table 2).
Cardiac dual‑energy CT in detecting flow‑limiting coronary
artery disease
On a per-patient basis, diagnostic accuracy, sensitivity,
specificity, PPV, NPV and AUC in detecting flow-limiting stenoses were 83.33%, 100%, 47.06%, 80.43%, 100%,
and 0.735 respectively for CCTA along; 96.30%, 97.30%,
94.12%, 97.30%, 94.12%, and 0.957 respectively for CCTA
combined with resting myocardial DE-CTP (Table 3).
On a per-vessel basis, diagnostic accuracy, sensitivity,
specificity, PPV, NPV and AUC in detecting flow-limiting stenoses were 76.16%, 100%, 56.47%, 67.54%, 100%,
and 0.777 respectively for CCTA along; 95.68%, 96.10%,
95.29%, 94.87%, 96.43%, and 0.956 respectively for CCTA
combined with resting myocardial DE-CTP (Table 4).
CCTA plus resting DE-CTP showed significantly better
diagnostic performance than CCTA alone in the detection of flow-limiting stenoses on both a per-patient basis
Li et al. BMC Medical Imaging
(2022) 22:32
Page 5 of 8
Fig. 2 Match between coronary stenosis severity and resting DE-CTP. Curved multiplanar reconstruction CCTA reveals obstructive coronary
artery disease with severe stenosis in RCA (A), LAD (B) and LCX (C). D Resting DE-CTP shows myocardial perfusion defects in anteroseptal,
anterolateral, inferior walls and a subendocardial perfusion defect in inferolateral wall. This 63-year-old male subsequently underwent invasive
coronary angiography (F–H) and PET (I) which confirmed the DE CT results. E, J are three-dimensional volume rendering technique (3D-VRT)
and three-dimensional maximum intensity projection (3D-MIP) of CCTA respectively. DE-CTP = dual-energy CT perfusion; CCTA = coronary CT
angiography; RCA = right coronary artery; LAD = left anterior artery, LCX = left anterior descending; PET = positron emission tomography
Table 2 Diagnostic performance of resting DE-CTP
Per segment (n = 918)
Per territory (n = 162)
Per patient (n = 54)
Accuracy
89.43 (821/918) [87.26–91.35]
91.98 (149/162) [86.67–95.66]
94.44 (51/54) [84.61–98.84]
Sensitivity
95.52 (320/335) [92.72–97.47]
97.56 (80/82) [91.47–99.70]
100.00 (37/37) [90.51–100.00]
Specificity
85.93 (501/583) [82.84–88.65]
86.25 (69/80) [76.73–92.93]
82.35 (14/17) [56.57–96.20]
PPV
79.60 (320/402) [75.32–83.44]
87.91 (80/91) [79.40–93.81]
92.50 (37/40) [79.61–98.43]
NPV
97.09 (501/516) [95.25–98.36]
97.18 (69/71) [90.19–99.66]
100 (14/14) [76.80–100]
AUC
0.907 [0.887–0.925]
0.919 [0.866–0.956]
0.912 [0.803–0.972]
Data are % (raw data) [95% confidence interval] for accuracy, sensitivity, specificity, PPV, and NPV. Data are value [95% confidence interval] for AUC
DE-CTP = dual-energy CT perfusion; PPV = positive predictive value; NPV = negative predictive value; AUC = area under the receiver operating characteristic curve
Table 3 Per-patient diagnostic performance of CCTA and CCTA
plus resting DE-CTP for detection of flow-limiting stenoses
CCTA
Table 4 Per-vessel diagnostic performance of CCTA and CCTA
plus resting DE-CTP for detection of flow-limiting stenoses
CCTA plus resting DE‑CTP
CCTA
CCTA plus resting DE‑CTP
Accuracy
83.33 (45/54) [70.71–92.08]
96.30 (52/54) [87.25–99.55]
Accuracy
Sensitivity
100.00 (37/37) [90.51–100.00]
97.30 (36/37) [85.84–99.93]
Sensitivity 100.00 (77/77) [95.32–100.00] 96.10 (74/77) [89.03–99.19]
76.16 (125/162) [69.92–83.38] 95.68 (155/162) [89.72–97.43]
Specificity
47.06 (8/17) [22.98–72.19]
94.12 (16/17) [71.31–99.85]
Specificity 56.47 (48/85) [45.28–67.20]
95.29 (81/85) [88.39–98.70]
PPV
80.43 (37/46) [66.09–90.64]
97.30 (36/37) [85.84–99.93]
PPV
67.54 (77/114) [58.14–76.01]
94.87 (74/78) [87.39–98.59]
NPV
100 .00 (8/8) [63.06–100.00]
94.12 (16/17) [70.28–99.88]
NPV
100.00 (48/48) [92.60–100.00] 96.43 (81/84) [89.92–99.26]
AUC
0.735 [0.598–0.846]
0.957 [0.864–0.939]
AUC
0.777 [0.705–0.839]
0.956 [0.912–0.982]
Data are % (raw data) [95% confidence interval] for accuracy, sensitivity,
specificity, PPV, and NPV; Data are value [95% confidence interval] for AUC
Data are % (raw data) [95% confidence interval] for accuracy, sensitivity,
specificity, PPV, and NPV. Data are value [95% confidence interval] for AUC
CCTA = coronary CT angiography; DE-CTP = dual-energy CT perfusion;
PPV = positive predictive value; NPV = negative predictive value; AUC = area
under the receiver operating characteristic curve
CCTA = coronary CT angiography; DE-CTP = dual-energy CT perfusion;
PPV = positive predictive value; NPV = negative predictive value; AUC = area
under the receiver operating characteristic curve
Li et al. BMC Medical Imaging
(2022) 22:32
(AUC, 0.957 vs. 0.735, p = 0.0005) and per-vessel basis
(AUC, 0.956 vs. 0.777, p < 0.0001) (Fig. 3).
When DE-CTP and CCTA were combined, the number
of false positive patients with flow-limiting stenoses was
reduced from nine to one, the PPV improved to 97.30%
from 80.43%, and the specificity improved to 94.12%
from 47.06%. Additionally, 5 in 54 (9%) patients showed
myocardial perfusion defects with no obstructive stenosis on CCTA combined with DE-CTP and were confirmed by ICA combined with 13N-ammonia PET. That is
to say that compared with CCTA along, DE-CTP combined with CCTA successfully avoided five false negative
patients in our study.
The inter-observer agreement was “excellent” for DECTP (k = 0.90, P < 0.001) and on a per-territory basis, and
was "excellent" for CCTA (k = 0.91, P < 0.001) on a pervessel basis.
Discussion
Our study demonstrates that resting cardiac DE-CTP has
a high diagnostic accuracy in detecting myocardial perfusion defects and provides an additional clinical value
by reducing rates of false-positive and false-negative
patients beyond CCTA in patients suspected of CAD.
Our results are similar with previous studies in demonstrating an excellent ability for combined CTA and
resting CTP in detecting flow-limiting coronary stenoses [8, 14]. Our results support the concept that resting DE-CTP provides additional value to include or
exclude CAD beyond anatomic CCTA data. In comparison with their studies enrolled patients presenting with
acute chest pain in emergency department, we enrolled
Page 6 of 8
patients presenting with acute or stable chest pain highly
suspected of CAD and therefore had an expansion of
different groups in evaluating the resting CTP in triage
patients for invasive examination and treatment. Additionally, the CTP image set in their studies was from conventional CCTA datasets. Whereas, CTP in our study
was the iodine maps from dual-energy scan mode. A
previous work by our groups demonstrated that dualenergy CT iodine maps is superior to conventional CTP
in detecting myocardial perfusion defects [15]. For DECTP, dual-energy CT iodine maps has great power to
reduce beam-hardening artifacts and enhance difference
between perfusion defects and health myocardium [9, 16,
17]. The current result also extends our previous study by
combined CCTA with resting DE-CTP in detecting flowlimiting coronary stenoses in cohorts suspected CAD
patients presenting with chest pain [15]. And above all,
three-dimensional CT rendering used in current study
established one to one relationship between each myocardial segment and the coronary artery that supplies it,
providing accurate registration between them (Fig. 1D).
In keeping with prior reports, our results also demonstrate that in addition to improving ability of detecting flow-limiting coronary stenoses, combined CCTA
with DE-CTP successfully detected five patients (9%)
which abnormal perfusion without obstructive stenosis
(≥ 50%) [18]. That is to say that 9% (5/54) patients of our
study population refrained from false negative results.
However, the prevalence of abnormal perfusion without
obstructive stenosis was relatively lower than previous
reports [19]. This may be because the prevalence abnormal perfusion without obstructive stenosis was more
Fig. 3 Area under the receiver operating characteristic curve (AUC) of per-patient (A) and per-vessel (B) performance of CCTA and CCTA plus
resting DE-CTP for the detection of flow-limiting stenoses. ★P < 0.05 for comparison of AUC between CCTA and CCTA plus resting DE-CTP
Li et al. BMC Medical Imaging
(2022) 22:32
Page 7 of 8
often in females than in males [20], whereas the percent
of the female population (41%) was less than males in our
study.
The diagnostic work-up of patients suspected of CAD
at presentation is typically oriented toward the detection of a hemodynamically relevant obstructive stenosis,
which serves as the basis for further treatment decisions.
However, a considerable number of patients who have
angina and signs of ischemia at presentation do not
have significant obstructive disease, obstructive stenosis
as defined by 50% or greater diameter stenosis [21–24].
Additionally, recurrent angina after successful percutaneous coronary intervention remains a clinically relevant
issue occurring in a non-negligible percentage of patients
[25].
Moreover, DE-CTP derived iodine maps allow a quantitative analysis of myocardial iodine uptake in mg/ mL
which is directly proportional to myocardial blood supply that are additive to routine single-energy CT, which
mostly provides density-based information [26, 27].
Future investigations should also evaluate their potential use in assessing and quantifying efficacy of coronary
revascularization.
Acknowledgements
Not applicable.
Study limitations
Author details
1
Department of Radiology, Beijing Chao-Yang Hospital, Capital Medical University, 8 Gongren Tiyuchang Nanlu, Chaoyang District, Beijing 100020, China.
2
Department of Radiology, Xuanwu Hospital of Capital Medical University, No.
45, Chang-Chun Street, Xicheng District, Beijing 100053, China.
Several limitations of this study should be described here.
First, an absolute quantitative approach was not used to
determine the myocardial perfusion defects. Second, the
relatively small number of patients included in this study
limits the statistical power and strength of the conclusions. This reflects the logistical difficulties involved in
carrying out multimodality imaging. Although small, the
results are encouraging but need to be tested on a larger
cohort. Third, in view of technical intermodality differences between dual-energy CT and PET in the higher
spatial resolution (namely, dual-energy CT), leading to
slight differences in the visualisation of the transmurality
of perfusion defects, we did non evaluate the transmurality of the perfusion defects. Fourth, ICA + PET is considered the gold standard in this study. Nevertheless, it
should be acknowledged that ICA plus invasive fractional
flow reserve (iFFR) is the unequivocal new gold standard
for flow-limiting lesions.
Conclusions
In this study, resting cardiac DE-CTP demonstrates a
high diagnostic accuracy in detecting myocardial perfusion defects and provides an additional clinical value
by reducing rates of false-positive and false-negative
patients beyond CCTA in patients suspected of CAD.
Future studies involving larger numbers of patients will
be necessary for the validation of our findings.
Authors’ contributions
WL: Conception or design of the work, Drafted the work or substantively
revised it. FY: Methodology, Software, Data curation. ML: Visualization, Investigation. CY: Investigation, Project administration. The authors have approved
the submitted version (and any substantially modified version that involves
the author’s contribution to the study). All authors read and approved the final
manuscript.
Funding
The authors state that this work has not received any funding.
Availability of data and materials
The datasets used and/or analysed during the current study are available from
the corresponding author on reasonable request.
Declarations
Ethics approval and consent to participate
The Institutional Review Board of Beijing Chaoyang Hospital approved this
study with a number of 2017-k-127, and patients provided informed consent.
The authors declare that the methods were carried out in accordance with the
Declaration of Helsinki.
Consent for publication
Not applicable.
Competing interests
The authors declare that they have no competing interests.
Received: 11 November 2021 Accepted: 22 February 2022
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