Society for Cardiovascular Magnetic Resonance 2022 Cases of SCMR case series.

"Cases of SCMR" is a case series on the SCMR website (https://www.scmr.org) for the purpose of education. The cases reflect the clinical presentation, and the use of cardiovascular magnetic resonance (CMR) in the diagnosis and management of cardiovascular disease. The 2022 digital collection of cases are presented in this manuscript.

Prognostic value of noninvasive combined anatomic/functional assessment by cardiac CT in patients with suspected coronary artery disease - Comparison with invasive coronary angiography and nuclear myocardial perfusion imaging for the five-year-follow up of the CORE320 multicenter study.

BACKGROUND: Few data exist on long-term outcome in patients undergoing combined coronary CT angiography (CTA) and myocardial CT perfusion imaging (CTP) as well as invasive coronary angiography (ICA) and single photon emission tomography (SPECT). METHODS: At 16 centers, 381 patients were followed for major adverse cardiac events (MACE) for the CORE320 study. All patients underwent coronary CTA, CTP, and SPECT before ICA within 60 days. Prognostic performance according binary results (normal/abnormal) was assessed by 5-year major cardiovascular events (MACE) free survival and area under the receiver-operating-characteristic curve (AUC). RESULTS: Follow up beyond 2-years was available in 323 patients. MACE-free survival rate was greater among patients with normal combined CTA-CTP findings compared to ICA-SPECT: 85 vs. 80% (95% confidence interval [CI] for difference 0.1, 11.3) though event-free survival time was similar (4.54 vs. 4.37 years, 95% CI for difference: -0.03, 0.36). Abnormal results by combined CTA-CTP was associated with 3.83 years event-free survival vs. 3.66 years after abnormal combined ICA-SPECT (95% CI for difference: -0.05, 0.39). Predicting MACE by AUC also was similar: 65 vs. 65 (difference 0.1; 95% CI -4.6, 4.9). When MACE was restricted to cardiovascular death, myocardial infarction, or stroke, AUC for CTA-CTP was 71 vs. 60 by ICA-SPECT (difference 11.2; 95% CI -1.0, 19.7). CONCLUSIONS: Combined CTA-CTP evaluation yields at least equal 5-year prognostic information as combined ICA-SPECT assessment in patients presenting with suspected coronary artery disease. Noninvasive cardiac CT assessment may eliminate the need for diagnostic cardiac catheterization in many patients. CLINICAL TRIAL REGISTRATION: NCT00934037.

Hidden Burden of Electronic Health Record-Identified Familial Hypercholesterolemia: Clinical Outcomes and Cost of Medical Care.

Background Familial hypercholesterolemia ( FH ), is a historically underdiagnosed, undertreated, high-risk condition that is associated with a high burden of cardiovascular morbidity and mortality. In this study, we use a population-based approach using electronic health record ( EHR )-based algorithms to identify FH . We report the major adverse cardiovascular events, mortality, and cost of medical care associated with this diagnosis. Methods and Results In our 1.18 million EHR- eligible cohort, International Classification of Diseases, Ninth Revision ( ICD -9) code-defined hyperlipidemia was categorized into FH and non- FH groups using an EHR algorithm designed using the modified Dutch Lipid Clinic Network criteria. Major adverse cardiovascular events, mortality, and cost of medical care were analyzed. A priori associated variables/confounders were used for multivariate analyses using binary logistic regression and linear regression with propensity score-based weighted methods as appropriate. EHR FH was identified in 32 613 individuals, which was 2.7% of the 1.18 million EHR cohort and 13.7% of 237 903 patients with hyperlipidemia. FH had higher rates of myocardial infarction (14.77% versus 8.33%; P<0.0001), heart failure (11.82% versus 10.50%; P<0.0001), and, after adjusting for traditional risk factors, significantly correlated to a composite major adverse cardiovascular events variable (odds ratio, 4.02; 95% CI, 3.88-4.16; P<0.0001), mortality (odds ratio, 1.20; CI, 1.15-1.26; P<0.0001), and higher total revenue per-year (incidence rate ratio, 1.30; 95% CI, 1.28-1.33; P<0.0001). Conclusions EHR -based algorithms discovered a disproportionately high prevalence of FH in our medical cohort, which was associated with worse outcomes and higher costs of medical care. This data-driven approach allows for a more precise method to identify traditionally high-risk groups within large populations allowing for targeted prevention and therapeutic strategies.

Two rare complications of myocardial infarction: a case report.

BACKGROUND: Mechanical complications following myocardial infarction (MI) have decreased in incidence due to the widespread use of early percutaneous coronary revascularization methods. We describe two rare complications as well as their natural history and uncertainties of the ideal management approach. CASE SUMMARY: Sixty-two-year-old female with multiple cardiovascular disease risk factors who had a delayed presentation of ST-segment elevation myocardial infarction and went on to develop dissecting intramyocardial haematoma progressing to ventricular septal rupture and coronary ventricular fistula. DISCUSSION: Intramyocardial haematoma is a rare complication of MI. It is considered to be part of the continuum of myocardial rupture which our patient eventually developed in the form of ventricular septal defect. The second rare entity in the same patient was development of a coronary ventricular fistula of the infarct-related stented, artery. The best way of managing dissecting intramyocardial haematoma is unclear with conflicting data between conservative and invasive strategies. Our patient failed the conservative approach as she progressed to frank myocardial rupture.

Diagnostic accuracy of semi-automatic quantitative metrics as an alternative to expert reading of CT myocardial perfusion in the CORE320 study.

AIMS: To determine the diagnostic accuracy of semi-automatic quantitative metrics compared to expert reading for interpretation of computed tomography perfusion (CTP) imaging. METHODS: The CORE320 multicenter diagnostic accuracy clinical study enrolled patients between 45 and 85 years of age who were clinically referred for invasive coronary angiography (ICA). Computed tomography angiography (CTA), CTP, single photon emission computed tomography (SPECT), and ICA images were interpreted manually in blinded core laboratories by two experienced readers. Additionally, eight quantitative CTP metrics as continuous values were computed semi-automatically from myocardial and blood attenuation and were combined using logistic regression to derive a final quantitative CTP metric score. For the reference standard, hemodynamically significant coronary artery disease (CAD) was defined as a quantitative ICA stenosis of 50% or greater and a corresponding perfusion defect by SPECT. Diagnostic accuracy was determined by area under the receiver operating characteristic curve (AUC). RESULTS: Of the total 377 included patients, 66% were male, median age was 62 (IQR: 56, 68) years, and 27% had prior myocardial infarction. In patient based analysis, the AUC (95% CI) for combined CTA-CTP expert reading and combined CTA-CTP semi-automatic quantitative metrics was 0.87(0.84-0.91) and 0.86 (0.83-0.9), respectively. In vessel based analyses the AUC's were 0.85 (0.82-0.88) and 0.84 (0.81-0.87), respectively. No significant difference in AUC was found between combined CTA-CTP expert reading and CTA-CTP semi-automatic quantitative metrics in patient based or vessel based analyses(p > 0.05 for all). CONCLUSION: Combined CTA-CTP semi-automatic quantitative metrics is as accurate as CTA-CTP expert reading to detect hemodynamically significant CAD.

Electronic health record phenotype in subjects with genetic variants associated with arrhythmogenic right ventricular cardiomyopathy: a study of 30,716 subjects with exome sequencing.

PurposeArrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart disease. Clinical follow-up of incidental findings in ARVC-associated genes is recommended. We aimed to determine the prevalence of disease thus ascertained.MethodsIndividuals (n = 30,716) underwent exome sequencing. Variants in PKP2, DSG2, DSC2, DSP, JUP, TMEM43, or TGFß3 that were database-listed as pathogenic or likely pathogenic were identified and evidence-reviewed. For subjects with putative loss-of-function (pLOF) variants or variants of uncertain significance (VUS), electronic health records (EHR) were reviewed for ARVC diagnosis, diagnostic criteria, and International Classification of Diseases (ICD-9) codes.ResultsEighteen subjects had pLOF variants; none of these had an EHR diagnosis of ARVC. Of 14 patients with an electrocardiogram, one had a minor diagnostic criterion; the rest were normal. A total of 184 subjects had VUS, none of whom had an ARVC diagnosis. The proportion of subjects with VUS with major (4%) or minor (13%) electrocardiogram diagnostic criteria did not differ from that of variant-negative controls. ICD-9 codes showed no difference in defibrillator use, electrophysiologic abnormalities or nonischemic cardiomyopathies in patients with pLOF or VUSs compared with controls.ConclusionpLOF variants in an unselected cohort were not associated with ARVC phenotypes based on EHR review. The negative predictive value of EHR review remains uncertain.

Gastric Bypass Surgery Produces a Durable Reduction in Cardiovascular Disease Risk Factors and Reduces the Long-Term Risks of Congestive Heart Failure.

BACKGROUND: Obesity and its association with reduced life expectancy are well established, with cardiovascular disease as one of the major causes of fatality. Metabolic surgery is a powerful intervention for severe obesity, resulting in improvement in comorbid diseases and in cardiovascular risk factors. This study investigates the relationship between metabolic surgery and long-term cardiovascular events. METHODS AND RESULTS: A cohort of Roux-en-Y gastric bypass surgery (RYGB) patients was tightly matched by age, body mass index, sex, Framingham Risk Score, smoking history, use of antihypertension medication, diabetes mellitus status, and calendar year with a concurrent cohort of nonoperated control patients. The primary study end points of major cardiovascular events (myocardial infarction, stroke, and congestive heart failure) were evaluated using Cox regression. Secondary end points of longitudinal cardiovascular risk factors were evaluated using repeated-measures regression. The RYGB and matched controls (N=1724 in each cohort) were followed for up to 12 years after surgery (overall median of 6.3 years). Kaplan-Meier analysis revealed a statistically significant reduction in incident major composite cardiovascular events (P=0.017) and congestive heart failure (0.0077) for the RYGB cohort. Adjusted Cox regression models confirmed the reductions in severe composite cardiovascular events in the RYGB cohort (hazard ratio=0.58, 95% CI=0.42-0.82). Improvements of cardiovascular risk factors (eg, 10-year cardiovascular risk score, total cholesterol, high-density lipoprotein, systolic blood pressure, and diabetes mellitus) were observed within the RYGB cohort after surgery. CONCLUSIONS: Gastric bypass is associated with a reduced risk of major cardiovascular events and the development of congestive heart failure.

Prognostic Value of Combined CT Angiography and Myocardial Perfusion Imaging versus Invasive Coronary Angiography and Nuclear Stress Perfusion Imaging in the Prediction of Major Adverse Cardiovascular Events: The CORE320 Multicenter Study.

Purpose To compare the prognostic importance (time to major adverse cardiovascular event [MACE]) of combined computed tomography (CT) angiography and CT myocardial stress perfusion imaging with that of combined invasive coronary angiography (ICA) and stress single photon emission CT myocardial perfusion imaging. Materials and Methods This study was approved by all institutional review boards, and written informed consent was obtained. Between November 2009 and July 2011, 381 participants clinically referred for ICA and aged 45-85 years were enrolled in the Combined Noninvasive Coronary Angiography and Myocardial Perfusion Imaging Using 320-Detector Row Computed Tomography (CORE320) prospective multicenter diagnostic study. All images were analyzed in blinded independent core laboratories, and a panel of physicians adjudicated all adverse events. MACE was defined as revascularization (>30 days after index ICA), myocardial infarction, or cardiac death; hospitalization for chest pain or congestive heart failure; or arrhythmia. Late MACE was defined similarly, except for patients who underwent revascularization within the first 182 days after ICA, who were excluded. Comparisons of 2-year survival (time to MACE) used standard Kaplan-Meier curves and restricted mean survival times bootstrapped with 2000 replicates. Results An MACE (49 revascularizations, five myocardial infarctions, one cardiac death, nine hospitalizations for chest pain or congestive heart failure, and one arrhythmia) occurred in 51 of 379 patients (13.5%). The 2-year MACE-free rates for combined CT angiography and CT perfusion findings were 94% negative for coronary artery disease (CAD) versus 82% positive for CAD and were similar to combined ICA and single photon emission CT findings (93% negative for CAD vs 77% positive for CAD, P < .001 for both). Event-free rates for CT angiography and CT perfusion versus ICA and single photon emission CT for either positive or negative results were not significantly different for MACE or late MACE (P > .05 for all). The area under the receiver operating characteristic curve (AUC) for combined CT angiography and CT perfusion (AUC = 68; 95% confidence interval [CI]: 62, 75) was similar (P = .36) to that for combined ICA and single photon emission CT (AUC = 71; 95% CI: 65, 79) in the identification of MACE at 2-year follow-up. Conclusion Combined CT angiography and CT perfusion enables similar prediction of 2-year MACE, late MACE, and event-free survival similar to that enabled by ICA and single photon emission CT. © RSNA, 2017 Online supplemental material is available for this article.

The Effect of Heart Rate on Exposure Window and Best Phase for Stress Perfusion Computed Tomography: Lessons From the CORE320 Study.

OBJECTIVES: The aim of this study is to evaluate the effect of heart rate on exposure window, best phase, and image quality for stress computed tomography perfusion (CTP) in the CORE320 study. METHODS: The CTP data sets were analyzed to determine the best phase for perfusion analysis. A predefined exposure window covering 75% to 95% of the R-R cycle was used. RESULTS: Of the 368 patients included in the analysis, 93% received oral ß blockade before the rest scan. The median heart rate during the stress acquisition was 69 bpm (interquartile range [IQR], 60-77). The median best phase was 81% (IQR, 76-90), and length of exposure window was 22% (IQR, 19-24). The best phase was significantly later in the cardiac cycle with higher heart rates (P < 0.001), and higher heart rates resulted in a small, but higher number of poor quality scans (6%, P < 0.001). The median effective dose of the stress scan was 5.3 mSv (IQR, 3.8-6.1). CONCLUSIONS: Stress myocardial CTP imaging can be performed using prospective electrocardiography triggering, an exposure window of 75% to 95%, and ß-blockade resulting in good or excellent image quality in the majority (80%) of patients while maintaining a low effective radiation dose.

Endocardial-epicardial distribution of myocardial perfusion reserve assessed by multidetector computed tomography in symptomatic patients without significant coronary artery disease: insights from the CORE320 multicentre study.

AIM: Previous animal studies have demonstrated differences in perfusion and perfusion reserve between the subendocardium and subepicardium. 320-row computed tomography (CT) with sub-millimetre spatial resolution allows for the assessment of transmural differences in myocardial perfusion reserve (MPR) in humans. We aimed to test the hypothesis that MPR in all myocardial layers is determined by age, gender, and cardiovascular risk profile in patients with ischaemic symptoms or equivalent but without obstructive coronary artery disease (CAD). METHODS AND RESULTS: A total of 149 patients enrolled in the CORE320 study with symptoms or signs of myocardial ischaemia and absence of significant CAD by invasive coronary angiography were scanned with static rest and stress CT perfusion. Myocardial attenuation densities were assessed at rest and during adenosine stress, segmented into 3 myocardial layers and 13 segments. MPR was higher in the subepicardium compared with the subendocardium (124% interquartile range [45, 235] vs. 68% [22,102], P < 0.001). Moreover, MPR in the septum was lower than in the inferolateral and anterolateral segments of the myocardium (55% [19, 104] vs. 89% [37, 168] and 124% [54, 270], P < 0.001). By multivariate analysis, high body mass index was significantly associated with reduced MPR in all myocardial layers when adjusted for cardiovascular risk factors (P = 0.02). CONCLUSION: In symptomatic patients without significant coronary artery stenosis, distinct differences in endocardial-epicardial distribution of perfusion reserve may be demonstrated with static CT perfusion. Low MPR in all myocardial layers was observed specifically in obese patients.

Myocardial CT perfusion imaging and SPECT for the diagnosis of coronary artery disease: a head-to-head comparison from the CORE320 multicenter diagnostic performance study.

PURPOSE: To compare the diagnostic performance of myocardial computed tomographic (CT) perfusion imaging and single photon emission computed tomography (SPECT) perfusion imaging in the diagnosis of anatomically significant coronary artery disease (CAD) as depicted at invasive coronary angiography. MATERIALS AND METHODS: This study was approved by the institutional review board. Written informed consent was obtained from all patients. Sixteen centers enrolled 381 patients from November 2009 to July 2011. Patients underwent rest and adenosine stress CT perfusion imaging and rest and either exercise or pharmacologic stress SPECT before and within 60 days of coronary angiography. Images from CT perfusion imaging, SPECT, and coronary angiography were interpreted at blinded, independent core laboratories. The primary diagnostic parameter was the area under the receiver operating characteristic curve (Az). Sensitivity and specificity were calculated with use of prespecified cutoffs. The reference standard was a stenosis of at least 50% at coronary angiography as determined with quantitative methods. RESULTS: CAD was diagnosed in 229 of the 381 patients (60%). The per-patient sensitivity and specificity for the diagnosis of CAD (stenosis ≥50%) were 88% (202 of 229 patients) and 55% (83 of 152 patients), respectively, for CT perfusion imaging and 62% (143 of 229 patients) and 67% (102 of 152 patients) for SPECT, with Az values of 0.78 (95% confidence interval: 0.74, 0.82) and 0.69 (95% confidence interval: 0.64, 0.74) (P = .001). The sensitivity of CT perfusion imaging for single- and multivessel CAD was higher than that of SPECT, with sensitivities for left main, three-vessel, two-vessel, and one-vessel disease of 92%, 92%, 89%, and 83%, respectively, for CT perfusion imaging and 75%, 79%, 68%, and 41%, respectively, for SPECT. CONCLUSION: The overall performance of myocardial CT perfusion imaging in the diagnosis of anatomic CAD (stenosis ≥50%), as demonstrated with the Az, was higher than that of SPECT and was driven in part by the higher sensitivity for left main and multivessel disease.

Ceramide-activated phosphatase mediates fatty acid-induced endothelial VEGF resistance and impaired angiogenesis.

Endothelial dysfunction, including endothelial hyporesponsiveness to prototypical angiogenic growth factors and eNOS agonists, underlies vascular pathology in many dysmetabolic states. We investigated effects of a saturated free fatty acid, palmitic acid (PA), on endothelial cell responses to VEGF. PA-pretreated endothelial cells had markedly diminished Akt, eNOS, and ERK activation responses to VEGF, despite normal VEGFR2 phosphorylation. PA inhibited VEGF-induced angiogenic cord formation in Matrigel, and PA-treated endothelial cells accumulated early species (C16) ceramide. The serine palmitoyltransferase inhibitor myriocin reversed these defects. Protein phosphatase 2A (PP2A) became more eNOS-associated in PA-treated cells; the PP2A inhibitor okadaic acid reversed PA-induced signaling defects. Mice fed a diet high in saturated fat for 2 to 3 weeks had impaired i) aortic Akt and eNOS phosphorylation to infused VEGF, ii) ear angiogenic responses to intradermal adenoviral-VEGF injection, and iii) vascular flow recovery to hindlimb ischemia as indicated by laser Doppler and αVß3 SPECT imaging. High-fat feeding did not impair VEGF-induced signaling or angiogenic responses in mice with reduced serine palmitoyltransferase expression. Thus, de novo ceramide synthesis is required for these detrimental PA effects. The findings demonstrate an endothelial VEGF resistance mechanism conferred by PA, which comprises ceramide-induced, PP2A-mediated dephosphorylation of critical activation sites on enzymes central to vascular homeostasis and angiogenesis. This study defines potential molecular targets for preservation of endothelial function in metabolic syndrome.

Computed tomography angiography and perfusion to assess coronary artery stenosis causing perfusion defects by single photon emission computed tomography: the CORE320 study.

AIMS: To evaluate the diagnostic power of integrating the results of computed tomography angiography (CTA) and CT myocardial perfusion (CTP) to identify coronary artery disease (CAD) defined as a flow limiting coronary artery stenosis causing a perfusion defect by single photon emission computed tomography (SPECT). METHODS AND RESULTS: We conducted a multicentre study to evaluate the accuracy of integrated CTA-CTP for the identification of patients with flow-limiting CAD defined by ≥50% stenosis by invasive coronary angiography (ICA) with a corresponding perfusion deficit on stress single photon emission computed tomography (SPECT/MPI). Sixteen centres enroled 381 patients who underwent combined CTA-CTP and SPECT/MPI prior to conventional coronary angiography. All four image modalities were analysed in blinded independent core laboratories. The prevalence of obstructive CAD defined by combined ICA-SPECT/MPI and ICA alone was 38 and 59%, respectively. The patient-based diagnostic accuracy defined by the area under the receiver operating characteristic curve (AUC) of integrated CTA-CTP for detecting or excluding flow-limiting CAD was 0.87 [95% confidence interval (CI): 0.84-0.91]. In patients without prior myocardial infarction, the AUC was 0.90 (95% CI: 0.87-0.94) and in patients without prior CAD the AUC for combined CTA-CTP was 0.93 (95% CI: 0.89-0.97). For the combination of a CTA stenosis ≥50% stenosis and a CTP perfusion deficit, the sensitivity, specificity, positive predictive, and negative predicative values (95% CI) were 80% (72-86), 74% (68-80), 65% (58-72), and 86% (80-90), respectively. For flow-limiting disease defined by ICA-SPECT/MPI, the accuracy of CTA was significantly increased by the addition of CTP at both the patient and vessel levels. CONCLUSIONS: The combination of CTA and perfusion correctly identifies patients with flow limiting CAD defined as ≥50 stenosis by ICA causing a perfusion defect by SPECT/MPI.

Aligning coronary anatomy and myocardial perfusion territories: an algorithm for the CORE320 multicenter study.

BACKGROUND: Appropriate clinical decisions concerning diagnosis and treatment of coronary artery disease rely on correct integration of data on coronary anatomy and myocardial perfusion. The purpose of this article is to introduce a new left ventricular segmentation model for improved alignment of coronary arterial segments and myocardial perfusion territories, designed for the CORE320 study. METHODS AND RESULTS: CORE320 is a prospective, multicenter study with a primary objective to evaluate the diagnostic accuracy of 320-row detector computed tomography (CT) to detect coronary artery luminal stenosis and corresponding myocardial perfusion deficits in patients with suspected coronary artery disease compared with the gold standard of conventional coronary angiography and single-photon emission CT myocardial perfusion imaging. We describe a 19-coronary segment and 13-myocardial territory alignment model, its application in both standard and CT image data sets, and the adjudication process of the initial cohort of patients recruited for the CORE320 study. Adjudication committees reviewed the images of the first 101 gold standard and 107 CT data sets. On the basis of the presented model and rules, all cases for adjudication were correctly identified. During image review, 6 (5.9%) gold standard and 9 (8.4%) CT data sets needed further realignment not triggered by the algorithm. CONCLUSIONS: We present a vascular territory distribution model developed for the CORE320 multicenter study, which accounts for variability in coronary anatomy and potential myocardial perfusion territory overlap.

Myocardial perfusion by CT versus hybrid imaging.

Coronary computed tomography angiography (CTA) is a reliable diagnostic test for the anatomic diagnosis of obstructive coronary artery disease (CAD). Although coronary CTA shows high sensitivity and negative predictive value for detecting stenosis greater than or equal to 50% diameter, it is limited in its ability to diagnose myocardial ischemia. Advances in computed tomography (CT) technology alone and technology that hybridizes CT with single-photon emission CT and positron emission tomography allow for the combined anatomic and physiologic diagnosis of CAD. This article summarizes these combined technologies, emphasizing the merits and limitations of each technology and their clinical implications.

A stepwise approach to the visual interpretation of CT-based myocardial perfusion.

Cardiovascular anatomic and functional testing have been longstanding and key components of cardiac risk assessment. As part of that strategy, CT-based imaging has made steady progress, with coronary computed tomography angiography (CTA) now established as the most sensitive noninvasive strategy for assessment of significant coronary artery disease. Myocardial CT perfusion imaging (CTP), as the functional equivalent of coronary CTA, is being tested in currently ongoing multicenter trials and is proposed to enhance the accuracy of coronary CTA alone. However, unlike coronary CTA that has published guidelines for interpretation and is rapidly gaining applicability in the noninvasive risk assessment paradigms, myocardial CTP is rapidly evolving, and guidance on a standard approach to its interpretation is lacking. In this article we describe a practical stepwise approach for interpretation of myocardial CTP that should add to the clinical applicability of this modality. These steps include (1) coronary CTA interpretation for potentially obstructive atherosclerosis, (2) reconstruction and preprocessing of myocardial CTP images, (3) image quality assessment and the identification of potentially confounding artifacts, (4) rest and stress image interpretation for enhancement patterns and areas of hypoattenuation, and (5) correlation of coronary anatomy and myocardial perfusion deficits. This systematic review uses already published methods from multiple clinical studies and is intended for general usage, independent of the platform used for image acquisition.

CT-based myocardial perfusion imaging-practical considerations: acquisition, image analysis, interpretation, and challenges.

Methods for non-invasive, cardiac risk assessment have historically relied on exercise stress testing with or without echocardiography or radionuclide imaging and pharmacological stress testing when appropriate. More recently, CT-based modalities like CT angiography (CTA) have been shown to reliably differentiate low from high-risk coronary disease. The advent of newer CT technology now allows for CT-based myocardial perfusion imaging (CTP) that provides functional information, that when analyzed with anatomic data from CTA, can provide a comprehensive risk assessment strategy. In this review, we discuss the research and implementation; as well as the quantitative, semiquantitative, and qualitative methods of image analysis of CT-based perfusion. We also discuss the present state of technology and challenges associated with the methodology. In each section, when appropriate, we provide some information regarding the translation of these methods being utilized in the international, multicenter CORE320 study that is evaluating the combined CT-based imaging (CTA and CTP) strategy of risk assessment in comparison to the combined reference standard of radionuclide myocardial perfusion imaging and invasive angiography.

CT perfusion: ready for prime time.

Advancements in computed tomography (CT) technology have revolutionized clinical practice, particularly regarding the noninvasive assessment of coronary artery disease (CAD). The versatility of cardiac CT has rendered multiple applications including assessment of cardiac structure and function, myocardial viability, and coronary anatomy. The merits of cardiac computed tomography angiography (CTA) have been proven for the detection, and particularly the exclusion, of CAD. However, CTA becomes limited in the presence of significant CAD. Its inability to consistently identify lesion-associated ischemia may necessitate additional radionuclide myocardial perfusion imaging. Myocardial computed tomography perfusion imaging (CTP) has emerged as a useful and convenient method to immediately assess myocardial ischemia. In this review, we discuss the current state of CTP including available technology, its performance to date from current literature, and future challenges to this field.

Quantitative and qualitative analysis and interpretation of CT perfusion imaging.

Coronary artery disease (CAD) remains the leading cause of death in the United States. Rest and stress myocardial perfusion imaging has an important role in the non-invasive risk stratification of patients with CAD. However, diagnostic accuracies have been limited, which has led to the development of several myocardial perfusion imaging techniques. Among them, myocardial computed tomography perfusion imaging (CTP) is especially interesting as it has the unique capability of providing anatomic- as well as coronary stenosis-related functional data when combined with computed tomography angiography (CTA). The primary aim of this article is to review the qualitative, semi-quantitative, and quantitative analysis approaches to CTP imaging. In doing so, we will describe the image data required for each analysis and discuss the advantages and disadvantages of each approach.