Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

Patient satisfaction with coronary CT angiography versus invasive coronary angiography: results of a single-center randomized trial

OBJECTIVE

Because there is evidence for a clinical benefit of using coronary computed tomography (CT) angiography instead of invasive coronary angiography (ICA) in patients with suspected coronary artery disease (CAD), we ascertained if patient satisfaction could represent an important barrier to implementation of coronary CT in clinical practice.

MATERIALS AND METHODS

A total of 329 patients with suspected CAD and clinical indication for ICA were randomly assigned to undergo either CT or ICA for guiding treatment. Satisfaction for both groups was assessed by patient questionnaire completed twice, ≥24 h after CT or ICA, and at follow-up after a median of 3.7 years. Assessment included preparation, concern, comfort, helplessness, pain, willingness to undergo tests again, overall satisfaction, and preference. Pearson's chi-square test and Wilcoxon rank-sum test were used.

RESULTS

Overall, 91% of patients undergoing CT (152/167) and 86% undergoing ICA completed assessment (140/162, p = 0.19). Patients reported being significantly better prepared for CT, less concerned about the test, and felt less helpless than during ICA (all: p < 0.001). Subjective pain (horizontal nonmarked visual analogue scale) was significantly lower for CT (6.9 ± 14.7) than for ICA (17.1 ± 22.7; p < 0.001). At follow-up, significantly more patients in the CT group reported very good satisfaction with communication of findings compared with the ICA group (p < 0.001) and 92% would recommend the institution to someone referred for the same examination.

CONCLUSIONS

Results from our single-center randomized study show very good satisfaction with coronary CT compared to ICA. Thus, superior acceptance of CT should be considered in shared decision-making.

CLINICAL RELEVANCE STATEMENT

This evaluation of patient satisfaction in a randomized study shows that patients' preference is in line with the clinical benefit provided by CT and also suggests to prefer a CT-first strategy in suspected coronary artery disease.

KEY POINTS

• Subjective pain was significantly lower for coronary CT angiography than for invasive coronary angiography and patients felt better prepared and less concerned about CT. • Patients were overall more satisfied with coronary CT angiography than invasive coronary angiography in a randomized controlled trial. • After a median follow-up of 3.7 years, more patients in the CT group indicated very good satisfaction with the communication of findings and with the examination itself.

A scoping review of person-centred care strategies used in diagnostic Nuclear Medicine

INTRODUCTION

Person-centred care (PCC) emphasises the need for the health care professional to prioritise individual patient needs, thereby fostering a collaborative and emphatic environment that empowers patients to actively participate in their own care. This article will explore the purpose of PCC in Nuclear Medicine (NM), while discussing strategies that may be used to implement PCC during diagnostic NM examinations performed on adult patients.

METHODS

The scoping review was conducted in accordance with the Joanna Briggs Institute methodology. The search was performed on PubMed, Embase and Cinhal in June 2023 and included studies in English, Spanish, Portuguese and Italian. The research equation combined keywords and Medical Subject Heading terms (MeSH) related to person-centred care (PCC), for all types of nuclear medicine diagnostic examinations performed. Three independent review authors screened all abstracts and titles, and all eligible full-text publications were included in this scoping review.

RESULTS

Fifty-three articles, published between 1993 and 2022, met the inclusion criteria for this scoping review. Seven articles were published in 2015 while 56.6 % of all included studies were performed in Europe. Most studies (n = 39/53) focused on the patients only, with the identified patient benefits being: improve patient experience (67.9 %), increase patient comfort (13.2 %), increase patient knowledge (5.7 %), reduction of patient anxiety (9.4 %) and reduction of waiting/scan time (3.8 %).

CONCLUSION

The scoping review identified a lack of research investigating the use of person-centred care strategies in NM. Future research will focus on using an international survey to explore this topic in nuclear medicine departments overseas.

IMPLICATIONS FOR PRACTICE

By applying PCC principles, the NM professional can improve the patient care pathway and increase patient satisfaction, leading to enhanced clinical outcomes.

Stress-rest dynamic-CT myocardial perfusion imaging in the management of myocardial bridging: A "one-stop shop" exam

Myocardial bridging (MB) is a congenital anomaly characterized by the intramyocardial coronary course that can cause coronary compression during systole leading to myocardial ischemia, often with the concomitant presence of endothelial dysfunction.Improvements in computed tomography (CT) technology have increased the burden of MB detection during coronary-CT (cCT) but their anatomical and functional assessment is often challenging. A stress-rest myocardial perfusion imaging (MPI) by single-photon emission CT (SPECT) is usually required to decide the correct patient management. However, SPECT has long acquisition protocols, poor spatial resolution, and significant radiation doses for the patient. The recent advances in CT scan technology have allowed the evaluation of stress-rest MPI, representing a promising alternative to SPECT.In this paper, we report six cases of MBs assessed with cCT examination and further evaluated with a stress-rest dynamic-CT MPI and SPECT. A reversible perfusion defect in the left anterior descending (LAD) territory segments potentially due to MB was detected in two of six patients, and they were referred for heart team evaluation.In conclusion, cCT and stress-rest dynamic-CT MPI allowed to detect MBs, evaluate their functional significance, and decide the patients' management in a "one-stop shop" examination.

Learning objective

Improvements in computed tomography (CT) technology have increased the burden of myocardial bridging (MB) detection during coronary-CT but their anatomical and functional assessment is often challenging.A stress-rest myocardial perfusion imaging (MPI) by single-photon emission CT (SPECT) is then usually required to decide the correct patient management.Recent advances in CT scan technology have allowed the evaluation of stress-rest MPI, that represent a promising alternative to SPECT.

Strengths and weaknesses of alternative noninvasive imaging approaches for microvascular ischemia

Structural and functional abnormalities of coronary microvasculature are highly prevalent in several clinical settings and often associated with worse clinical outcomes. Therefore, there is a growing interest in the detection and treatment of this, often overlooked, disease. Coronary angiography allows the assessment of the Coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR). However, the measurement of these parameters is not always feasible because of limited technical availability and the need for a cardiac catheterization with a small but real risk of potential complications. Recent advances in non-invasive imaging techniques allow the assessment of coronary microvascular function with good accuracy and reproducibility. The objective of this review is to discuss the strengths and weaknesses of alternative non-invasive approaches used in the diagnosis of coronary microvascular dysfunction (CMD), highlighting the most recent advances for each imaging modality.

The BYPASS-CTCA Study: the value of Computed Tomography Cardiac Angiography (CTCA) in improving patient-related outcomes in patients with previous bypass operation undergoing invasive coronary angiography: Study Protocol of a Randomised Controlled Trial

Background

Patients with ischaemic heart disease and previous coronary artery bypass grafting (CABG) often need coronary evaluation by means of invasive coronary angiography (ICA). ICA in such patients is technically more challenging and carries a higher risk of complications including kidney damage, myocardial infarction, stroke and death. Improvements in Computed Tomography Cardiac Angiography (CTCA) technology have ensured its emergence as a useful clinical tool in CABG assessment, allowing for its potential use in planning interventional procedures in this patient group.

Methods

The BYPASS-CTCA study is a prospective, single centre, randomised controlled trial assessing the value of upfront CTCA in patients with previous surgical revascularisation undergoing ICA procedures. A total of 688 patients with previous CABG, requiring ICA for standard indications, will be recruited and randomised to receive ICA alone, or CTCA prior to angiography. Subjects will be followed up over a 12-month period post procedure. The primary endpoints are ICA procedural duration, incidence of contrast-induced nephropathy (CIN) and patient satisfaction scores post ICA. Secondary endpoints include contrast dose (mL) and radiation dose (mSv) during ICA, number of catheters used, angiography-related complications and cost-effectiveness of CTCA (QALY) over 12 months.

Discussion

The study will investigate the hypothesis that CTCA prior to ICA in patients with previous CABG can reduce procedural duration, post-procedural kidney damage and improve patient satisfaction, therefore strengthening its role in this group of patients.

Trial Registration

The study is registered on ClinicalTrials.gov which is a resource maintained by the U.S. National Library of Medicine. Registration number NCT03736018.

A survey study investigating perceptions and acceptance of the whole-body imaging techniques used for the diagnosis of myeloma

INTRODUCTION

The purpose of this study was to investigate patient perceptions and acceptance of the three whole-body imaging (WBI) modalities used for diagnosing myeloma; radiographic skeletal survey (RSS), low-dose whole-body computed tomography (LD-WBCT) and whole-body magnetic resonance imaging (WB-MRI). The secondary aim was to explore the factors affecting the acceptance of whole-body imaging for myeloma.

METHODS

60 participants (median age = 58.5 years old) recruited from three NHS trusts and social media completed a survey in which they scored their experiences of each WBI modality on nine 5-point rating scales. Spearman's correlation coefficient, Kruskal-Wallis, Mann-Whitney and Wilcoxon signed-rank tests were used to compare scores between different WBI techniques. Participants were invited to provide additional open text responses for interpretation using thematic analysis.

RESULTS

All modalities demonstrated high levels of acceptability (median score = 4). WB-MRI was perceived as more stressful (p=<0.01) and claustrophobic (p=<0.01) than RSS and LD-WBCT. Thematic analysis showed patients understood the importance of imaging but had concerns about exacerbated pain and the results. WB-MRI was difficult to tolerate due to its duration. Respondents were averse to the physical manipulation required for RSS while remaining stationary was perceived as a benefit of LD-WBCT and WB-MRI. Staff interactions had both positive and negative effects on acceptance.

CONCLUSIONS

Despite the psychological and physical burdens of WBI, patients accepted its role in facilitating diagnosis. Staff support is vital for facilitating a positive whole-body imaging experience. Healthcare practitioners can improve WBI acceptance by understanding the burdens imposed by WBI and adopting the personalised care model.

IMPLICATIONS FOR PRACTICE

Patient experience can be improved by tailoring examinations to individual needs. RSS can be as burdensome as other WBI techniques and could be superseded by LD-WBCT or WB-MRI.

The effect of video-based educational program on satisfaction and comfort in patients undergoing transradial coronary angiography: A single-blinded, randomized controlled trial

Cardiac catheterization has been the most widely used diagnostic method, and in most cases, invasive diagnostic methods are associated with stress and concern that can affect the satisfaction and comfort of patients undergoing transradial coronary angiography. In this randomized controlled trial, a total of 89 patients undergoing transradial coronary angiography were recruited using convenience sampling. Then, the patients were assigned to two groups of intervention and control using blocked randomization, as those in the intervention group received video-based patient education and those in the control group received no training. Data were collected using the Persian version of the patient satisfaction questionnaire and the visual analog scale. The variables were measured before, 2, 4, and 8 hours after the angiography. The results indicated that, after the intervention, the mean scores of satisfaction and comfort in the intervention group were higher than in the control group (P < .001). Video-based educational strategies should be integrated into the nursing interventions to improve patients' health status.

Myocardial perfusion assessment in the infarct core and penumbra zones in an in-vivo porcine model of the acute, sub-acute, and chronic infarction

OBJECTIVES

To assess the longitudinal changes of microvascular function in different myocardial regions after myocardial infarction (MI) using myocardial blood flow derived by dynamic CT perfusion (CTP-MBF), and compare CTP-MBF with the results of cardiac magnetic resonance (CMR) and histopathology.

METHODS

The CTP scanning was performed in a MI porcine model 1 day (n = 15), 7 days (n = 10), and 3 months (n = 5) following induction surgery. CTP-MBF was measured in the infarcted myocardium, penumbra, and remote myocardium, respectively. CMR perfusion and histopathology were performed for validation.

RESULTS

From baseline to follow-up scans, CTP-MBF presented a stepwise increase in the infarcted myocardium (68.51 ± 11.04 vs. 86.73 ± 13.32 vs. 109.53 ± 26.64 ml/100 ml/min, p = 0.001) and the penumbra (104.92 ± 29.29 vs. 120.32 ± 24.74 vs. 183.01 ± 57.98 ml/100 ml/min, p = 0.008), but not in the remote myocardium (150.05 ± 35.70 vs. 166.66 ± 38.17 vs. 195.36 ± 49.64 ml/100 ml/min, p = 0.120). The CTP-MBF correlated with max slope (r = 0.584, p < 0.001), max signal intensity (r = 0.357, p < 0.001), and time to max (r = - 0.378, p < 0.001) by CMR perfusion. Moreover, CTP-MBF defined the infarcted myocardium on triphenyl tetrazolium chloride staining (AUC: 0.810, p < 0.001) and correlated with microvascular density on CD31 staining (r = 0.561, p = 0.002).

CONCLUSION

CTP-MBF could quantify the longitudinal changes of microvascular function in different regions of the post-MI myocardium, which demonstrates good agreement with contemporary CMR and histopathological findings.

KEY POINTS

• The CT perfusion-based myocardial blood flow (CTP-MBF) could quantify the microvascular impairment in different myocardial regions after myocardial infarction (MI) and track its recovery over time. • The assessment of CTP-MBF is in good agreement with contemporary cardiac MRI and histopathological findings, which potentially facilitates a rapid approach for pathophysiological insights following MI.

Clinical quantitative cardiac imaging for the assessment of myocardial ischaemia

Cardiac imaging has a pivotal role in the prevention, diagnosis and treatment of ischaemic heart disease. SPECT is most commonly used for clinical myocardial perfusion imaging, whereas PET is the clinical reference standard for the quantification of myocardial perfusion. MRI does not involve exposure to ionizing radiation, similar to echocardiography, which can be performed at the bedside. CT perfusion imaging is not frequently used but CT offers coronary angiography data, and invasive catheter-based methods can measure coronary flow and pressure. Technical improvements to the quantification of pathophysiological parameters of myocardial ischaemia can be achieved. Clinical consensus recommendations on the appropriateness of each technique were derived following a European quantitative cardiac imaging meeting and using a real-time Delphi process. SPECT using new detectors allows the quantification of myocardial blood flow and is now also suited to patients with a high BMI. PET is well suited to patients with multivessel disease to confirm or exclude balanced ischaemia. MRI allows the evaluation of patients with complex disease who would benefit from imaging of function and fibrosis in addition to perfusion. Echocardiography remains the preferred technique for assessing ischaemia in bedside situations, whereas CT has the greatest value for combined quantification of stenosis and characterization of atherosclerosis in relation to myocardial ischaemia. In patients with a high probability of needing invasive treatment, invasive coronary flow and pressure measurement is well suited to guide treatment decisions. In this Consensus Statement, we summarize the strengths and weaknesses as well as the future technological potential of each imaging modality.

Quantitative evaluation of postintervention foot blood supply in patients with peripheral artery disease by computed tomography perfusion

OBJECTIVE

The aim of this study was to quantitatively evaluate the changes of the foot's blood supply after endovascular treatment in patients with peripheral artery disease (PAD) using foot computed tomography (CT) perfusion.

METHODS

Nineteen patients who underwent endovascular treatment for PAD between January 2018 and November 2018 were included in the study. Perfusion CT scanning was performed before and after intervention with the measurement of ankle-brachial index. Regions of interest were selected from two arteries and four different tissues per foot. Perfusion maps of blood volume, blood flow, permeability surface area product, time to peak (TTP), mean transit time (MTT), mean slope of increase (MSI), Tmax, and impulse response function (IRFt₀) were constructed and calculated by the perfusion analysis software. Wilcoxon signed rank test was performed on the eight parameter pairs of the limbs on the treated and untreated sides before and after intervention in the 19 patients.

RESULTS

Differences in blood flow, MTT, TTP, Tmax, MSI, and IRFt₀ on the treated side of the tissue perfusion group and statistical difference in blood flow, MTT, and MSI on the treated side of the arterial perfusion group were observed (all P < .05). Ankle-brachial index improved from 0.41 ± 0.11 to 0.76 ± 0.10 (P < .001). For the untreated side, TTP of the tissue perfusion group was significantly shortened (by 7.71 seconds) after surgery (P = .006), whereas there were no differences in the other parameters. In addition, no significant differences in parameters were observed on the untreated side of the arterial perfusion group. The average radiation dose per phase of perfusion scan was 0.00097 mSv. Moreover, the hyperperfusion zone in the plantar dermis and periosteum reappeared after revascularization.

CONCLUSIONS

Perfusion CT is a feasible and repeatable approach for quantifying blood supply in patients with PAD. The increase of blood flow, MSI, and MTT shortening suggest blood supply improvement after revascularization in both arterial perfusion and tissue perfusion. In addition, TTP may be a sensitive indicator of blood supply changes in tissue perfusion.

Patient Preferences for Coronary CT Angiography with Stress Perfusion, SPECT, or Invasive Coronary Angiography

Background Patient preference is pivotal for widespread adoption of tests in clinical practice. Patient preferences for invasive versus other noninvasive tests for coronary artery disease are not known. Purpose To compare patient acceptance and preferences for noninvasive and invasive cardiac imaging in North and South America, Asia, and Europe. Materials and Methods This was a prospective 16-center trial in 381 study participants undergoing coronary CT angiography with stress perfusion, SPECT, and invasive coronary angiography (ICA). Patient preferences were collected by using a previously validated questionnaire translated into eight languages. Responses were converted to ordinal scales and were modeled with generalized linear mixed models. Results In patients in whom at least one test was associated with pain, CT and SPECT showed reduced median pain levels, reported on 0-100 visual analog scales, from 20 for ICA (interquartile range [IQR], 4-50) to 6 for CT (IQR, 0-27.5) and 5 for SPECT (IQR, 0-25) (P < .001). Patients from Asia reported significantly more pain than patients from other continents for ICA (median, 25; IQR, 10-50; P = .01), CT (median, 10; IQR, 0-30; P = .02), and SPECT (median, 7; IQR, 0-28; P = .03). Satisfaction with preparation differed by continent and test (P = .01), with patients from Asia reporting generally lower ratings. Patients from North America had greater percentages of "very high" or "high" satisfaction than patients from other continents for ICA (96% vs 82%, respectively; P < .001) and SPECT (95% vs 79%, respectively; P = .04) but not for CT (89% vs 86%, respectively; P = .70). Among all patients, CT was preferred by 54% of patients, compared with 18% for SPECT and 28% for ICA (P < .001). Conclusion For cardiac imaging, patients generally favored CT angiography with stress perfusion, while study participants from Asia generally reported lowest satisfaction. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Woodard and Nguyen in this issue.

Myocardial ischemia testing with computed tomography: emerging strategies

Although cardiac computed tomography (CT) has high negative predictive value to exclude obstructive coronary artery disease (CAD), particularly in the low to intermediate risk population, it has low specificity in the diagnosis of ischemia-inducing lesions. This inability to predict hemodynamically significant stenosis hampers the ability of CT to be an effective gatekeeper for invasive angiography and to guide appropriate revascularization. Recent advances in CT technology have resulted in the development of multiple techniques to provide hemodynamic information and detect lesion-specific ischemia, namely CT perfusion (CTP), CT-derived fractional flow reserve (CT-FFR) and coronary transluminal attenuation gradient (TAG). In this article, we provide a perspective on these emerging CT techniques in the evaluation of myocardial ischemia.

Symptoms and quality of life in patients with suspected angina undergoing CT coronary angiography: a randomised controlled trial

BACKGROUND

In patients with suspected angina pectoris, CT coronary angiography (CTCA) clarifies the diagnosis, directs appropriate investigations and therapies, and reduces clinical events. The effect on patient symptoms is currently unknown.

METHODS

In a prospective open-label parallel group multicentre randomised controlled trial, 4146 patients with suspected angina due to coronary heart disease were randomised 1:1 to receive standard care or standard care plus CTCA. Symptoms and quality of life were assessed over 6 months using the Seattle Angina Questionnaire and Short Form 12.

RESULTS

Baseline scores indicated mild physical limitation (74±0.4), moderate angina stability (44±0.4), modest angina frequency (68±0.4), excellent treatment satisfaction (92±0.2) and moderate impairment of quality of life (55±0.3). Compared with standard care alone, CTCA was associated with less marked improvements in physical limitation (difference -1.74 (95% CIs, -3.34 to -0.14), p=0.0329), angina frequency (difference -1.55 (-2.85 to -0.25), p=0.0198) and quality of life (difference -3.48 (-4.95 to -2.01), p<0.0001) at 6 months. For patients undergoing CTCA, improvements in symptoms were greatest in those diagnosed with normal coronary arteries or who had their preventative therapy discontinued, and least in those with moderate non-obstructive disease or had a new prescription of preventative therapy (p<0.001 for all).

CONCLUSIONS

While improving diagnosis, treatment and outcome, CTCA is associated with a small attenuation of the improvements in symptoms and quality of life due to the detection of moderate non-obstructive coronary artery disease.

TRIAL REGISTRATION NUMBER

NCT01149590.

Update on Computed Tomography Myocardial Perfusion Imaging

PURPOSE OF REVIEW

Computed tomography (CT) coronary angiography is a well-validated non-invasive technique for accurate and expedient diagnosis of coronary artery disease (CAD). However, a limitation of coronary CT angiography (CCTA) is its limited capability to identify physiologically significant stenoses, which may eventuate the need for further functional testing. Stress CT myocardial perfusion imaging (CT-MPI) is an emerging technique that has the ability to identify flow-limiting stenoses.

RECENT FINDINGS

The combination of CCTA coronary and CT-MPI has transformed the modality from a tool to assess anatomy and morphology to a modality capable of simultaneous assessment of coronary stenoses and their physiologic significance. A growing number of studies have demonstrated the feasibility and diagnostic accuracy of CT-MPI in comparison to a number of reference standard modalities for CAD diagnosis, including single-photon emission CT, cardiovascular magnetic resonance imaging, and invasive coronary angiography with and without fractional flow-reserve testing.

SUMMARY

While there is still a need for consensus regarding acquisition techniques as well as analysis and interpretation of CT-MPI, with further validation, it is likely to become a powerful adjunctive tool to CCTA in the management of patients with suspected coronary disease.

Computed tomography myocardial perfusion vs 15O-water positron emission tomography and fractional flow reserve

Objectives

Computed tomography (CT) can perform comprehensive cardiac imaging. We compared CT coronary angiography (CTCA) and CT myocardial perfusion (CTP) with ¹⁵O-water positron emission tomography (PET) and invasive coronary angiography (ICA) with fractional flow reserve (FFR).

Methods

51 patients (63 (61–65) years, 80 % male) with known/suspected coronary artery disease (CAD) underwent 320-multidetector CTCA followed by “snapshot” adenosine stress CTP. Of these 22 underwent PET and 47 ICA/FFR. Obstructive CAD was defined as CTCA stenosis >50 % and CTP hypoperfusion, ICA stenosis >70 % or FFR <0.80.

Results

PET hyperaemic myocardial blood flow (MBF) was lower in obstructive than non-obstructive territories defined by ICA/FFR (1.76 (1.32–2.20) vs 3.11 (2.44–3.79) mL/(g/min), P < 0.001) and CTCA/CTP (1.76 (1.32–2.20) vs 3.12 (2.44–3.79) mL/(g/min), P < 0.001). Baseline and hyperaemic CT attenuation density was lower in obstructive than non-obstructive territories (73 (71–76) vs 86 (84–88) HU, P < 0.001 and 101 (96–106) vs 111 (107–114) HU, P 0.001). PET hyperaemic MBF corrected for rate pressure product correlated with CT attenuation density (r = 0.579, P < 0.001). There was excellent per-patient sensitivity (96 %), specificity (85 %), negative predictive value (90 %) and positive predictive value (94 %) for CTCA/CTP vs ICA/FFR.

Conclusion

CT myocardial attenuation density correlates with ¹⁵O-water PET MBF. CTCA and CTP can accurately identify obstructive CAD.

Key Points

•CT myocardial perfusion can aid the assessment of suspected coronary artery disease.

• CT attenuation density from “snapshot” imaging is a marker of myocardial perfusion.

• CT myocardial attenuation density correlates with¹⁵O-water PET myocardial blood flow.

• CT attenuation density is lower in obstructive territories defined by invasive angiography.

• Diagnostic accuracy of CTCA+CTP is comparable to invasive angiography + fractional flow reserve.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-016-4404-5) contains supplementary material, which is available to authorized users.

Quantitative myocardial perfusion with stress dual-energy CT: iodine concentration differences between normal and ischemic or necrotic myocardium. Initial experience

OBJECTIVES

To determine whether the quantification of iodine with stress dual-energy computed tomography (DECT-S) allows for the discrimination between a normal and an ischemic or necrotic myocardium using magnetic resonance (MR) as a reference.

METHODS

This retrospective study was approved by the institutional review board, with waiver of informed consent. Thirty-six cardiac MR and DECT-S images from patients with suspected coronary artery disease were evaluated. Perfusion defects were visually determined, and myocardial iodine concentration was calculated by two observers using DECT colour-coded iodine maps. Iodine concentration differences were calculated using parametric tests. Receiver operating characteristic (ROC) curve analysis was conducted to estimate the optimal iodine concentration threshold for discriminating pathologic myocardium.

RESULTS

In total, 576 cardiac segments were evaluated. There were differences in mean iodine concentration (p < 0.001) between normal (2.56 ± 0.66 mg/mL), ischemic (1.98 ± 0.36 mg/dL) and infarcted segments (1.35 ± 0.57 mg/mL). A myocardium iodine concentration of 2.1 mg/mL represented the optimal threshold to discriminate between normal and pathologic myocardium (sensitivity 75 %, specificity 73.6 %, area under the curve 0.806). Excellent agreement was found in measured myocardium iodine concentration (intraclass correlation coefficient 0.814).

CONCLUSION

Cardiac DECT-S with iodine quantification may be useful to differentiate healthy and ischemic or necrotic myocardium.

KEY POINTS

• DECT-S allows for determination of myocardial iodine concentration as a quantitative perfusion parameter. • A high interobserver correlation exists in measuring myocardial iodine concentration with DECT-S. • Myocardial iodine concentration may be useful in the assessment of patients with CAD.