Subclinical coronary and aortic atherosclerosis detected by magnetic resonance imaging in type 1 diabetes with and without diabetic nephropathy

Heart-carotid pulse-wave velocity via laser-Doppler vibrometry as a biomarker for arterial stiffening: a feasibility study

Objective. Large artery stiffening leads to an increase in cardiovascular risk and organ damage of the kidneys, brain or the heart. Biomarkers that allow for early detection of this phenomenon are a point of interest in research, with pulse-wave velocity (PWV) having been proven useful in predicting and monitoring arterial stiffness. We previously introduced a laser Doppler vibrometry (LDV) prototype which can measure carotid-femoral PWV (cfPWV). In this work, we assess the feasibility of using the same device to infer heart-carotid pulse-transit time (hcPTT) as a first step towards measuring heart-carotid PWV (hcPWV). The advantage of hcPWV over cfPWV is that the ascending aorta, which is the most distensible segment of the aorta contributing most to total arterial compliance, is included in the arterial pathway.Approach. Signals were simultaneously acquired from a location on the chest (near either the base or the apex of the heart) and the right carotid artery for 100 patients (45% female). Fiducial points on the heart waveforms are associated with opening and closure (second heart sound; S2) of the aortic valve, which can be combined with, respectively, the foot and dicrotic notch (DN) of the carotid waveform to retrieve hcPTT. Considering two distinct heart-signal measurement sites, four hcPTT estimations are evaluated in about 94% of all measurements.Main results. Correlations between these and known predictors of arterial stiffness i.e. age, blood pressure and carotid-femoral PTT via applanation tonometry indicated that combining S2 from a heart-measurement site located at the base of the heart, with the carotid DN yields hcPTT providing convincing correlations with known determinants of arterial stiffness (ρ = 0.377 with age).Significance.We conclude that LDV may provide a corollary biomarker of arterial stiffness, encompassing the ascending aorta.

Screening for Subclinical Atherosclerosis and the Prediction of Cardiovascular Events in People with Type 1 Diabetes

People with type 1 diabetes (T1D) have a high cardiovascular disease (CVD) risk, which remains the leading cause of death in this population. Despite the improved control of several classic risk factors, particularly better glycaemic control, cardiovascular morbidity and mortality continue to be significantly higher than in the general population. In routine clinical practice, estimating cardiovascular risk (CVR) in people with T1D using scales or equations is often imprecise because much of the evidence comes from pooled samples of people with type 2 diabetes (T2D) and T1D or from extrapolations of studies performed on people with T2D. Given that T1D onsets at a young age, prolonged exposure to the disease and its consequences (e.g., hyperglycaemia, changes in lipid metabolism or inflammation) have a detrimental impact on cardiovascular health. Therefore, it is critical to have tools that allow for the early identification of those individuals with a higher CVR and thus be able to make the most appropriate management decisions in each case. In this sense, atherosclerosis is the prelude to most cardiovascular events. People with diabetes present pathophysiological alterations that facilitate atherosclerosis development and that may imply a greater vulnerability of atheromatous plaques. Screening for subclinical atherosclerosis using various techniques, mainly imaging, has proven valuable in predicting cardiovascular events. Its use enables the reclassification of CVR and, therefore, an individualised adjustment of therapeutic management. However, the available evidence in people with T1D is scarce. This narrative review provides and updated overview of the main non-invasive tests for detecting atherosclerosis plaques and their association with CVD in people with T1D.

Carotid ultrasonography as a strategy to optimize cardiovascular risk management in type 1 diabetes: a cohort study

BACKGROUND AND AIMS

Although cardiovascular disease (CVD) remains the leading cause of mortality in type 1 diabetes (T1D), the use of cardioprotective drugs is scarce. We aimed to evaluate the impact of carotid ultrasonography (US) on the improvement in cardiovascular risk factors (CVRFs) in T1D.

METHODS AND RESULTS

T1D patients without CVD meeting criteria for lipid treatment according to guidelines (age ≥ 40 years, nephropathy and/or ≥ 10 years of diabetes duration with ≥ 1 additional CVRFs) were included. The carotid-US group (US-G) underwent a standardized US protocol and CVRF assessment; recommendations were made according to subclinical atherosclerosis status. The control group (CG) followed usual clinical practice. Changes in CVRFs, specially statin use and LDL cholesterol levels, at 1 year were analysed. A total of 318 patients were included (51.3% female, mean age of 49.1 years and 25.5 years of diabetes duration): 211 in the US-G and 107 in the CG. Participants in the US-G had a higher baseline LDL cholesterol than controls (114 vs. 102 mg/dL; p < 0.001). Lipid-lowering treatment was modified in 38.9% in the US-G and 6.5% in the CG (p < 0.001). At 1 year, the US-G was more frequently on statins, had lower LDL cholesterol and 27% had stopped smoking (p < 0.001 for all). Changes were more pronounced in those with plaques (p < 0.001). In multivariate analyses adjusted for age, sex and other CVRFs, belonging to the US-G was independently associated with the intensification of lipid-lowering treatment (OR 10.47 [4.06-27.01]). Propensity score-matching analysis yielded similar results (OR 20.09 [7.86-51.37]).

CONCLUSION

Carotid-US is independently associated with an intensification of lipid-lowering therapy in a high-risk T1D population.

Status and Trends of the Association Between Diabetic Nephropathy and Diabetic Retinopathy From 2000 to 2021: Bibliometric and Visual Analysis

Background: Diabetic nephropathy (DN) and diabetic retinopathy (DR) are microvascular complications of diabetes that share a similar pathogenesis and clinical relevance. The study aimed to visually analyze the research status and development trend of the relationship between DN and DR by means of bibliometrics and knowledge mapping. Methods: Publications were collected from the Science Citation Index-Expanded of the Web of Science Core Collection between 2000 and 2021. CiteSpace, Alluvial Generator, and Microsoft Excel were used to analyze and present the data. Results: A total of 3,348 publications were retrieved and 3,285 were included in the analysis after deduplication. The publications demonstrated an annually increasing trend. The results of the collaborative network analysis showed that the United States, Steno Diabetes Center, and Tien Y. Wong were the most influential country, institution and author, in this field of research, respectively. The analysis of references and keywords showed that the pathogenesis of DN and DR and their relationship with cardiovascular disease are research hotspots. The clinical relevance and drug therapy for DN and DR will become frontiers of future research in this field. Conclusion: This study is the first to visualize the correlation between DN and DR using a bibliometric approach. This study provides a reference of research trends for scholars.

Long-term complications of type 1 diabetes: what do we know and what do we need to understand?

Long-term complications of type 1 diabetes (T1D) include microvascular complications and macrovascular disease. Despite the important advances in the treatment of T1D of the last decades, these complications still represent the leading cause of morbidity and mortality in patients with T1D. Extensive evidence indicates that structural and functional alterations of the kidney, retina, nerves and large arteries occur already in the first years after the onset of diabetes. We performed a comprehensive review of the available evidence on screening, diagnosis, prevention and treatment of vascular complications of T1D. In particular, we focused on three major challenges related to long-term complications of T1D: 1) finding of new biomarkers and diagnostic methods able to identify early signs of complications; 2) identifying specific risk factors for the development of these complications; 3) identifying and implementing new therapeutic strategies able to prevent the development and progression of vascular complications.

Non-invasive assessment of coronary endothelial function in children and adolescents with type 1 diabetes mellitus using isometric handgrip exercise-MRI: A feasibility study

Background

Type 1 diabetes mellitus (T1DM) in children and adolescents is associated with significant cardiovascular morbidity and mortality. Early detection of vascular dysfunction is key to patient management yet current assessment techniques are invasive and not suitable for pediatric patient populations. A novel approach using isometric handgrip exercise during magnetic resonance imaging (IHE-MRI) has recently been developed to evaluate coronary endothelial function non-invasively in adults. This project aimed to assess endothelium-dependent coronary arterial response to IHE-MRI in children with T1DM and in age matched healthy controls.

Materials and methods

Healthy volunteers and children with T1DM (>5 years) were recruited. IHE-MRI cross-sectional coronary artery area measurements were recorded at rest and under stress. Carotid intima media thickness (CIMT) and aortic pulse wave velocity (PWV) were assessed for comparison. Student’s t-tests were used to compare results between groups.

Results and discussion

Seven children with T1DM (3 female, median 14.8 years, mean 14.8 ± 1.9 years) and 16 healthy controls (7 female, median 14.8 years, mean 14.2 ± 2.4 years) participated. A significant increase in stress-induced cross-sectional coronary area was measured in controls (5.4 mm² at rest to 6.39 mm² under stress, 18.8 ± 10.7%, p = 0.0004). In contrast, mean area change in patients with T1DM was not significant (7.17 mm² at rest to 7.59 mm² under stress, 10.5% ± 28.1%, p = n.s.). There was no significant difference in the results for neither PWV nor CIMT between patients and controls, (5.3±1.5 m/s vs.4.8±0.7 m/s and 0.4±0.03mm vs.0.46 mm ± 0.03 respectively, both p = n.s.).

Conclusions

Our pilot study demonstrates the feasibility of using a totally non-invasive IHE-MRI technique in children and adolescents with and without T1DM. Preliminary results suggest a blunted endothelium-dependent coronary vasomotor function in children with T1DM (>5 years). Better knowledge and new methodologies may improve surveillance and care for T1DM patients to reduce cardiovascular morbidity and mortality.

Sexual Dimorphism of Coronary Artery Disease in a Low- and Intermediate-Risk Asymptomatic Population: Association with Coronary Vessel Wall Thickness at MRI in Women

Purpose

To demonstrate the association between coronary vessel wall thickness (VWT) measured at MRI and coronary artery disease (CAD) risk in asymptomatic groups at low and intermediate risk on the basis of Framingham score.

Materials and Methods

A total of 131 asymptomatic adults were prospectively enrolled. All participants underwent CT angiography for scoring CAD, and coronary VWT was measured at 3.0-T MRI. Nonlinear single and multivariable regression analyses with consideration for interaction with sex were performed to investigate the association of traditional atherosclerotic risk factors and VWT with CT angiography-based CAD scores.

Results

The analysis included 62 women and 62 men with low or intermediate Framingham score of less than 20%. Age (mean age, 45.0 years ± 14.5 [standard deviation]) and body mass index were not different between the groups. Age, sex, and VWT were individually significantly associated with all CT angiography-based CAD scores (P < .05). Additionally, sex was a significant effect modifier of the associations with all CAD scores. In men, age was the only statistically significant independent risk factor of CAD; in women, VWT was the only statistically significant independent surrogate associated with increased CAD scores (P < .05).

Conclusion

In asymptomatic women, VWT MRI was the primary independent surrogate of CAD, whereas age was the strongest risk factor in men. This study suggests that VWT may be used as a CAD surrogate in women at low or intermediate risk of CAD. Further longitudinal studies are required to determine the potential implication and use of this MRI technique for the preventative management of CAD in women.© RSNA, 2019.

The emerging role of cardiovascular magnetic resonance imaging in the assessment of cardiac involvement in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the commonest rheumatic disease in childhood and presents several subtypes according to the ILAR classification. JIA, specifically in its systemic form, may seriously damage various structures of the cardiovascular system. Other JIA phenotypes are also of interest, as cardiovascular disease (CVD) is underestimated and understudied, but chronic systemic inflammation and risk factors remained important contributors for CVD development. The currently applied non-invasive modalities, although they are important for the initial evaluation of JIA patients, frequently fail to detect the silent, subclinical forms of CVD. Cardiovascular magnetic resonance (CMR), due to its multifaceted capability in the detection of cardiovascular disease, can offer early, reproducible, non-invasive information about cardiovascular disease in JIA, allowing risk stratification and timely initiation /modification of cardiologic and anti-rheumatic treatment. However, lack of availability/expertise and high cost still hamper its application in the clinical cardio-rheumatic practice. The aim of the current article is to present an overview of CVD in JIA emphasizing the emerging role of CMR in early diagnosis and treatment follow-up of CVD in JIA patients.

Association of different biomarkers of renal function with D-dimer levels in patients with type 1 diabetes mellitus (renal biomarkers and D-dimer in diabetes)

Objective This study aimed to evaluate the association between different renal biomarkers with D-Dimer levels in diabetes mellitus (DM1) patients group classified as: low D-Dimer levels (< 318 ng/mL), which included first and second D-Dimer tertiles, and high D-Dimer levels (≥ 318 ng/mL), which included third D-Dimer tertile. Materials and methods D-Dimer and cystatin C were measured by ELISA. Creatinine and urea were determined by enzymatic method. Estimated glomerular filtration rate (eGFR) was calculated using CKD-EPI equation. Albuminuria was assessed by immunoturbidimetry. Presence of renal disease was evaluated using each renal biomarker: creatinine, urea, cystatin C, eGFR and albuminuria. Bivariate logistic regression analysis was performed to assess which renal biomarkers are associated with high D-Dimer levels and odds ratio was calculated. After, multivariate logistic regression analysis was performed to assess which renal biomarkers are associated with high D-Dimer levels (after adjusting for sex and age) and odds ratio was calculated. Results Cystatin C presented a better association [OR of 9.8 (3.8-25.5)] with high D-Dimer levels than albuminuria, creatinine, eGFR and urea [OR of 5.3 (2.2-12.9), 8.4 (2.5-25.4), 9.1 (2.6-31.4) and 3.5 (1.4-8.4), respectively] after adjusting for sex and age. All biomarkers showed a good association with D-Dimer levels, and consequently, with hypercoagulability status, and cystatin C showed the best association among them. Conclusion Therefore, cystatin C might be useful to detect patients with incipient diabetic kidney disease that present an increased risk of cardiovascular disease, contributing to an early adoption of reno and cardioprotective therapies.

Magnetic resonance imaging in heart failure, including coronary imaging: numbers, facts, and challenges

Coronary artery disease (CAD) is a major risk factor for the incidence and progression of heart failure (HF). HF is characterized by a substantial morbidity and mortality and its lifetime risk is estimated at approximately 20% for men and women. As patients are in most cases identified only after developing overt clinical symptoms, detecting early stages of CAD and HF is of paramount importance. Due to its non‐invasiveness, excellent soft‐tissue contrast, high spatial resolution, and multiparametric nature, cardiovascular magnetic resonance (CMR) imaging has emerged as a promising radiation‐free technique to assess a wide range of cardiovascular diseases such as CAD or HF, enabling a comprehensive evaluation of myocardial anatomy, regional and global function, and viability with the additional benefit of in vivo tissue characterization. CMR has the potential to enhance our understanding of coronary atherosclerosis and the aetiology of HF on functional and biological levels, to identify patients at risk for CAD or HF, and to enable individualized patient management and improved outcomes. Even though larger‐scale studies on the different applications of CMR for the assessment of heart failure are scarce, recent research highlighted new possible clinical applications for CMR in the evaluation of CAD and HF.

A Cylindrical, Inner Volume Selecting 2D-T2-Prep Improves GRAPPA-Accelerated Image Quality in MRA of the Right Coronary Artery

BACKGROUND

Two-dimensional (2D) spatially selective radiofrequency (RF) pulses may be used to excite restricted volumes. By incorporating a "pencil beam" 2D pulse into a T2-Prep, one may create a "2D-T2-Prep" that combines T2-weighting with an intrinsic outer volume suppression. This may particularly benefit parallel imaging techniques, where artefacts typically originate from residual foldover signal. By suppressing foldover signal with a 2D-T2-Prep, image quality may therefore improve. We present numerical simulations, phantom and in vivo validations to address this hypothesis.

METHODS

A 2D-T2-Prep and a conventional T2-Prep were used with GRAPPA-accelerated MRI (R = 1.6). The techniques were first compared in numerical phantoms, where per pixel maps of SNR (SNRmulti), noise, and g-factor were predicted for idealized sequences. Physical phantoms, with compartments doped to mimic blood, myocardium, fat, and coronary vasculature, were scanned with both T2-Preparation techniques to determine the actual SNRmulti and vessel sharpness. For in vivo experiments, the right coronary artery (RCA) was imaged in 10 healthy adults, using accelerations of R = 1,3, and 6, and vessel sharpness was measured for each.

RESULTS

In both simulations and phantom experiments, the 2D-T2-Prep improved SNR relative to the conventional T2-Prep, by an amount that depended on both the acceleration factor and the degree of outer volume suppression. For in vivo images of the RCA, vessel sharpness improved most at higher acceleration factors, demonstrating that the 2D-T2-Prep especially benefits accelerated coronary MRA.

CONCLUSION

Suppressing outer volume signal with a 2D-T2-Prep improves image quality particularly well in GRAPPA-accelerated acquisitions in simulations, phantoms, and volunteers, demonstrating that it should be considered when performing accelerated coronary MRA.

Coronary artery plaque imaging: Comparison of black‐blood MRI and 64‐multidetector computed tomography

Objective

To comparatively evaluate black-blood coronary arterial wall MRI and 64-multidetector computed tomography (64-MDCT) for detection and classification of coronary artery plaques.

Methods

We included 15 patients with confirmed coronary artery plaques in the proximal or middle segments of coronary arteries by 64-MDCT, who underwent black-blood coronary wall MRI at 1.5 T within 10 days. Cross-sectional coronary wall images were acquired using a 2D double-inversion-recovery, electrocardiograph-triggered, navigator-gated, fat-suppressed, turbo-spin-echo sequence on the coronary arteries with lesions from the ostium to the middle segment continuously without gap. The vessel cross-sectional area (CSA), luminal CSA, maximal wall thickness, plaque burden, contrast-to-noise ratio (CNR), and signal-to-noise ratio (SNR) were measured in each slice and subsequently compared with computed tomography angiography (CTA) images. CTA images were divided into 5-mm segments for side-by-side comparison with MRI.

Results

Of the 15 patients, 12 were enrolled in the study. Coronary plaques were found in 46 slices on both CTA and MRI. Plaques were classified to 3 groups based on CTA: calcified plaques (n = 11), soft plaques (n = 23), and mixed plaques (n = 12). In MRI, the plaque burden, maximal wall thickness, SNR, and CNR in the coronary walls containing plaques were greater than in the normal coronary walls (0.83 ± 0.08 vs. 0.73 ± 0.08, 1.88 ± 0.51 vs. 1.51 ± 0.26 mm, 12.95 ± 2.78 vs. 9.93 ± 2.31, and 6.76 ± 2.52 vs. 3.89 ± 1.54, respectively; P < 0.05). The luminal CSA at the plaque was smaller than in normal coronary walls (2.50 ± 1.50 vs. 4.72 ± 2.28 mm²; P < 0.05). The SNR in the soft plaque was significantly greater than in calcified and mixed plaques (P < 0.05).

Conclusions

Coronary wall MRI can identify coronary plaques in the proximal and middle segments and has the potential to differentiate plaque types based on signal intensity.

Von Willebrand Factor, ADAMTS13 and D-Dimer Are Correlated with Different Levels of Nephropathy in Type 1 Diabetes Mellitus

We have investigated whether von Willebrand factor, ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13), and D-Dimer were associated with different levels of renal function in patients with type 1 diabetes. Patients were classified according to level of renal function through estimated glomerular filtration rate: ≥90 and <130mL/min/1,73m2, n=52 (control group), ≥60 and <90mL/min/1,73m2, n=29 (mild renal dysfunction group), <60mL/min/1,73m2, n=28 (severe renal dysfunction group); and through urinary albumin excretion: normoalbuminuria, microalbuminuria and macroalbuminuria. Von Willebrand factor, ADAMTS13, and D-Dimer plasma levels were determined by enzyme-linked immunosorbent assay. ADAMTS13 activity was determined by fluorescence resonance energy transfer assay. Von Willebrand factor levels were increased in patients with mild (P=0.001) and severe (P<0.001) renal dysfunction as compared to the control group. ADAMTS13 levels were also increased in mild (P=0.029) and severe (P=0.002) renal dysfunction groups in comparison to the control group, while ADAMTS13 activity was increased only in the severe renal dysfunction group as compared to the control group (P=0.006). No significant differences were observed among the groups regarding von Willebrand factor/ADAMTS13 ratio. ADAMTS13 activity/ADAMTS13 levels ratio was reduced in patients with mild (P=0.013) and severe (P=0.015) renal dysfunction as compared to the control group. D-Dimer levels were increased in patients with mild (P=0.006) and severe (P<0.001) renal dysfunction as compared to the control group; it was also higher in patients with severe renal dysfunction as compared to the mild renal dysfunction group (P=0.019). Similar results were found for albuminuria classification. Increased von Willebrand factor, ADAMTS13, and D-Dimer levels and decreased ADAMTS13 activity/ADAMTS13 levels ratio are associated with renal dysfunction in patients with type 1 diabetes, suggesting that endothelial dysfunction and hypercoagulability are associated with nephropathy in type 1 diabetes.

MR imaging of the coronary vasculature: imaging the lumen, wall, and beyond

The characteristics of coronary artery disease are gradual thickening of the coronary walls and narrowing of the vascular lumen by the buildup of atherosclerosis plaques. These morphologic changes can be noninvasively detected by coronary magnetic resonance (MR) imaging/MR angiography (MRA). In addition, functional changes, such as coronary wall distensibility and flow changes, may also be evaluated with MR imaging. However, the application of current MR imaging/MRA techniques is limited in clinical practice because of several adverse technical and physiologic factors, such as cardiac and respiratory motion. Many technical innovations have been adopted to address these problems from multiple aspects.

Diabetes Complications in Childhood Diabetes-New Biomarkers and Technologies

A major challenge in preventing vascular complications in diabetes is the inability to identify high-risk patients at an early stage, emphasizing the importance of discovering new risk factors, technologies and therapeutic targets to reduce the development and progression of complications. Promising biomarkers which may improve risk stratification and serve as therapeutic targets, include: uric acid, insulin sensitivity, copeptin, SGLT-2 and Klotho/FGF-23. Non-invasive measures of macrovasuclar disease in youth, include: 1) pulse wave velocity to examine arterial stiffness; 2) carotid intima-media thickness to evaluate arterial thickness; 3) cardiac MRI to investigate cardiac function and structure. Novel microvascular measures include: GFR by iohexol clearance using filter paper to directly measure GFR, retinal vascular geometry to predict early retinal changes and corneal confocal microscopy to improve detection of early nerve loss to better predict diabetic neuropathy. Herein we will review technologies, novel biomarkers, and therapeutic targets in relation to vascular complications of diabetes.

Contribution of cardiovascular magnetic resonance in the evaluation of coronary arteries

Cardiovascular magnetic resonance (CMR) allows the nonradiating assessment of coronary arteries; to achieve better image quality cardiorespiratory artefacts should be corrected. Coronary MRA (CMRA) at the moment is indicated only for the detection of abnormal coronary origin, coronary artery ectasia and/or aneurysms (class I indication) and coronary bypass grafts (class II indication). CMRA utilisation for coronary artery disease is not yet part of clinical routine. However, the lack of radiation is of special value for the coronary artery evaluation in children and women. CMRA can assess the proximal part of coronary arteries in almost all cases. The best results have been observed in the evaluation of the left anterior descending and the right coronary artery, while the left circumflex, which is located far away from the coil elements, is frequently imaged with reduced quality, compared to the other two. Different studies detected an increase in wall thickness of the coronaries in patients with type I diabetes and abnormal renal function. Additionally, the non-contrast enhanced T1-weighed images detected the presence of thrombus in acute myocardial infarction. New techniques using delayed gadolinium enhanced imaging promise the direct visualization of inflamed plaques in the coronary arteries. The major advantage of CMR is the potential of an integrated protocol offering assessment of coronary artery anatomy, cardiac function, inflammation and stress perfusion-fibrosis in the same study, providing an individualized clinical profile of patients with heart disease.

Coronary artery wall imaging

Like X-Ray contrast angiography, MR coronary angiograms show the vessel lumens rather than the vessels themselves. Consequently, outward remodeling of the vessel wall, which occurs in subclinical coronary disease before luminal narrowing, cannot be seen. The current gold standard for assessing the coronary vessel wall is intravascular ultrasound, and more recently, optical coherence tomography, both of which are invasive and use ionizing radiation. A noninvasive, low-risk technique for assessing the vessel wall would be beneficial to cardiologists interested in the early detection of preclinical disease and for the safe monitoring of the progression or regression of disease in longitudinal studies. In this review article, the current state of the art in MR coronary vessel wall imaging is discussed, together with validation studies and recent developments.

Combined coronary lumen and vessel wall magnetic resonance imaging with i-T2prep: influence of nitroglycerin

It has been shown that sublingual nitroglycerin (NTG) improves image quality of coronary lumen magnetic resonance angiography. Our aim was to investigate the influence of NTG on coronary lumen and vessel wall image quality using a combined, single sequence approach (i-T2prep), which is able to image both within the known time frame of action of NTG. Ten healthy volunteers underwent right coronary artery lumen and vessel wall imaging using the i-T2prep sequence before and after administration of NTG. Image quality was assessed qualitatively and quantitatively. Diameter, length and wall thickness were also measured using dedicated semi-automatic software. NTG induced coronary vasodilatation (lumen diameter increased from 2.16 ± 0.32 to 2.52 ± 0.59 mm; p = 0.036). As a result, visualized lumen length (9.8 ± 2.6 to 11.4 ± 3.3 cm; p = 0.025) and qualitative lumen image quality (median 3 (interquartile range 2-3.25) vs. median 3 (interquartile range 3-4); p = 0.046) both improved. Vessel wall imaging also demonstrated a significant improvement in vessel wall sharpness after NTG (24.8 vs. 27.3 %; p = 0.036). This study demonstrates the benefits of NTG for coronary lumen and vessel wall imaging using a combined sequence, i-T2prep. The methodology described here has great potential for future pathophysiological studies.

Adventitial inflammation and its interaction with intimal atherosclerotic lesions

The presence of adventitial inflammation in correlation with atherosclerotic lesions has been recognized for decades. In the last years, several studies have investigated the relevance and impact of adventitial inflammation on atherogenesis. In the abdominal aorta of elderly Apoe^−/− mice, adventitial inflammatory structures were characterized as organized ectopic lymphoid tissue, and therefore termed adventitial tertiary lymphoid organs (ATLOs). These ATLOs possess similarities in development, structure and function to secondary lymphoid organs. A crosstalk between intimal atherosclerotic lesions and ATLOs has been suggested, and several studies could demonstrate a potential role for medial vascular smooth muscle cells in this process. We here review the development, phenotypic characteristics, and function of ATLOs in atherosclerosis. Furthermore, we discuss the possible role of medial vascular smooth muscle cells and their interaction between plaque and ATLOs.

Associations of atherosclerosis in the descending thoracic aorta on CTA with arterial stiffness and chronic kidney disease in asymptomatic patients with diabetes mellitus

The relation between atherosclerosis in the descending thoracic aortic (DTA), arterial stiffness and chronic kidney disease (CKD) in patients with diabetes mellitus (DM) remains unclear. The current aim was to evaluate associations of DTA atherosclerosis with arterial stiffness and parameters of CKD in asymptomatic patients with DM. A total of 213 asymptomatic patients with diabetes (mean age 52 years, 56% men) underwent cardiovascular risk assessment including multi-slice computed tomography (for non-invasive coronary angiography, from which DTA atherosclerosis can be derived), non-invasive assessment of arterial stiffness with applanation tonometry and assessment of renal function. Measurements of DTA atherosclerosis included assessment of DTA thickening and calcium score. Arterial stiffness was determined by the carotid-femoral pulse wave velocity (PWV), parameters of CKD included estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR). DTA atherosclerosis was present in 180 (84%) patients. Patients with DTA atherosclerosis had increased arterial stiffness, lower eGFR and higher UACR values. After multivariate correction, DTA calcium score was independently associated with PWV (β = 0.18, p = 0.04). Furthermore, both DTA maximal wall thickness and DTA calcium score were independently associated with eGFR (β = -7.37, p < 0.001 and β = -1.99, p < 0.003, respectively), but not with UACR. The increase in arterial stiffness by atherosclerosis seemed to be mediated by arterial calcification, while the DTA calcium score was independently associated with arterial stiffness, but not DTA maximal wall thickness. Furthermore, parameters of CKD in patients with DM had a distinct relationship with DTA atherosclerosis: DTA atherosclerosis was associated with eGFR but not with UACR.

MR imaging of myocardial infarction

Magnetic resonance (MR) imaging plays an important role in evaluation of various aspects of myocardial infarction (MI). MR imaging is useful in establishing the diagnosis of acute MI, particularly in patients who present with symptoms of MI but outside the diagnostic time frame of altered cardiac enzyme levels or with clinical features of acute MI but without an angiographic culprit lesion. MR imaging is valuable in establishing a diagnosis of chronic MI and distinguishing this condition from nonischemic cardiomyopathies, mainly through use of delayed-enhancement patterns. MR imaging also provides clinicians with several prognostic indicators that enable risk stratification, such as scar burden, microvascular obstruction, hemorrhage, and peri-infarct ischemia. The extent and transmurality of scar burden have been shown to have independent and incremental prognostic power over a range of left ventricular function. The extent of scarring at MR imaging is an important predictor of successful outcome after revascularization procedures, and extensive scarring in the lateral wall indicates poor outcome after cardiac resynchronization therapy. Scar size at MR imaging is also a useful surrogate end point in clinical trials. Finally, MR imaging can be used to detect complications of MI, such as aneurysms, pericarditis, ventricular septal defect, thrombus, and mitral regurgitation. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.335125722/-/DC1.

Prevalence of systolic and diastolic dysfunction in patients with type 1 diabetes without known heart disease: the Thousand & 1 Study

AIMS/HYPOTHESIS

Heart failure is one of the leading causes of mortality in type 1 diabetes. Early identification is vitally important. We sought to determine the prevalence and clinical characteristics associated with subclinical impaired systolic and diastolic function in type 1 diabetes patients without known heart disease.

METHODS

In this cross-sectional examination of 1,093 type 1 diabetes patients without known heart disease, randomly selected from the Steno Diabetes Center, complete clinical and echocardiographic examinations were performed and analysed in uni- and multivariable regression models.

RESULTS

The mean (SD) age was 49.6 (15) years, 53% of participants were men, and the mean duration of diabetes was 25.5 (15) years. Overall, 15.5% (n = 169) of participants had grossly abnormal systolic or diastolic function, including 1.7% with left ventricular ejection fraction (LVEF) < 45% and 14.4% with evidence of long-standing diastolic dysfunction. In univariable models, clinical characteristics associated with abnormal myocardial function were: age (per 10 years), OR (95% CI) 2.1 (1.8, 2.4); diabetes duration (per 10 years), 1.7 (1.4, 1.9); systolic BP ≥ 140 mmHg, 2.7 (1.9, 3.8); diastolic BP ≥ 90 mmHg, 1.8 (1.0, 3.1); estimated (e)GFR < 60 ml min(-1) 1.73 m(-2), 3.8 (2.5, 5.9); microalbuminuria, 2.0 (1.3, 3.0); macroalbuminuria, 5.9 (3.8, 9.3); proliferative retinopathy, 3.6 (2.3, 5.8); blindness, 10.1 (3.2, 31.6); and peripheral neuropathy, 3.8 (2.7, 5.3). In multivariable models only age (2.1 [1.7, 2.5]), female sex, (1.9 [1.2, 2.8]) and macroalbuminuria (5.2 [2.9, 10.3]) remained significantly associated with subclinical grossly abnormal myocardial function.

CONCLUSIONS/INTERPRETATION

Subclinical myocardial dysfunction is a common finding in type 1 diabetes patients without known heart disease. Type 1 diabetes patients with albuminuria are at greatly increased risk of having subclinical abnormal myocardial function compared with patients without albuminuria. Echocardiography may be particularly warranted in patients with albuminuria.

Quantitative imaging biomarkers for the evaluation of cardiovascular complications in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a prevalent condition in aged populations. Cardiovascular diseases are leading causes of death and disability in patients with T2DM. Traditional strategies for controlling the cardiovascular complications of diabetes primarily target a cluster of well-defined risk factors, such as hyperglycemia, lipid disorders and hypertension. However, there is controversy over some recent clinical trials aimed at evaluating efficacy of intensive treatments for T2DM. As a powerful tool for quantitative cardiovascular risk estimation, multi-disciplinary cardiovascular imaging have been applied to detect and quantify morphological and functional abnormalities in the cardiovascular system. Quantitative imaging biomarkers acquired with advanced imaging procedures are expected to provide new insights to stratify absolute cardiovascular risks and reduce the overall costs of health care for people with T2DM by facilitating the selection of optimal therapies. This review discusses principles of state-of-the-art cardiovascular imaging techniques and compares applications of those techniques in various clinical circumstances. Individuals measurements of cardiovascular disease burdens from multiple aspects, which are closely related to existing biomarkers and clinical outcomes, are recommended as promising candidates for quantitative imaging biomarkers to assess the responses of the cardiovascular system during diabetic regimens.

Contrast-enhanced cardiovascular magnetic resonance imaging of coronary vessel wall: state of art

Coronary wall imaging by cardiovascular magnetic resonance (CMR) emerges as a promising method to detect vascular injury and remodeling directly within the coronary vascular wall. In this review, the current evidence on coronary wall enhancement using CMR is presented and summarized, with particular focus on its ability to detect inflammation in atherosclerosis, Takayasu's arteritis, acute coronary syndromes and immune-mediated inflammatory vasculitides. The authors review the possible mechanisms of coronary wall contrast enhancement on CMR and discuss the technical considerations and limitations. Lastly, the potential clinical applications and possibilities for future research are proposed.

MR imaging of the arterial vessel wall: molecular imaging from bench to bedside

Cardiovascular diseases remain the leading cause of morbidity and mortality in the Western world and developing countries. In clinical practice, in vivo characterization of atherosclerotic lesions causing myocardial infarction, ischemic stroke, and other complications remains challenging. Imaging methods, limited to the assessment luminal stenosis, are the current reference standard for the assessment of clinically significant coronary and carotid artery disease and the guidance of treatment. These techniques do not allow distinction between stable and potentially vulnerable atherosclerotic plaque. Magnetic resonance (MR) imaging is a modality well suited for visualization and characterization of the relatively thin arterial vessel wall, because it allows imaging with high spatial resolution and excellent soft-tissue contrast. In clinical practice, atherosclerotic plaque components of the carotid artery and aorta may be differentiated and characterized by using unenhanced vessel wall MR imaging. Additional information can be gained by using clinically approved nonspecific contrast agents. With the advent of targeted MR contrast agents, which enhance specific molecules or cells, pathologic processes can be visualized at a molecular level with high spatial resolution. In this article, the pathophysiologic changes of the arterial vessel wall underlying the development of atherosclerosis will be first reviewed. Then basic principles and properties of molecular MR imaging contrast agents will be introduced. Additionally, recent advances in preclinical molecular vessel wall imaging will be reviewed. Finally, the clinical feasibility of arterial vessel wall imaging at unenhanced and contrast material-enhanced MR imaging of the aortic, carotid, and coronary vessel wall will be discussed.

Using advanced noninvasive imaging techniques to probe the links between regional coronary artery endothelial dysfunction and atherosclerosis

Cardiovascular disease remains the number one cause of death in the US annually. The development in recent years of imaging strategies that can identify coronary endothelial dysfunction noninvasively provides new information about the early presence and local spatial heterogeneity of endothelial function in patients with, and those at risk for, coronary artery disease. In this article, we will briefly review the mechanisms relating endothelial function and atherosclerosis, contemporary imaging strategies now able to quantify coronary endothelial function noninvasively, and recent insights on human coronary endothelial function.

Feasibility of coronary artery wall thickening assessment in asymptomatic coronary artery disease using phase-sensitive dual-inversion recovery MRI at 3T

OBJECTIVES

The purpose of this study was to (a) investigate the image quality of phase-sensitive dual-inversion recovery (PS-DIR) coronary wall imaging in healthy subjects and in subjects with known coronary artery disease (CAD) and to (b) investigate the utilization of PS-DIR at 3T in the assessment of coronary artery thickening in subjects with asymptomatic but variable degrees of CAD.

MATERIALS AND METHODS

A total of 37 subjects participated in this institutional review board-approved and HIPAA-compliant study. These included 21 subjects with known CAD as identified on multidetector computed tomography angiography (MDCT). Sixteen healthy subjects without known history of CAD were included. All subjects were scanned using free-breathing PS-DIR magnetic resonance imaging (MRI) for the assessment of coronary wall thickness at 3T. Lumen-tissue contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and quantitative vessel parameters including lumen area and wall thickness were measured. Statistical analyses were performed.

RESULTS

PS-DIR was successfully completed in 76% of patients and in 88% of the healthy subjects. Phase-sensitive signed-magnitude reconstruction, compared to modulus-magnitude images, significantly improved lumen-tissue CNR in healthy subjects (26.73±11.95 vs. 14.65±9.57, P<.001) and in patients (21.45±7.61 vs. 16.65±5.85, P<.001). There was no difference in image CNR and SNR between groups. In arterial segments free of plaques, coronary wall was thicker in patients in comparison to healthy subjects (1.74±0.27 mm vs. 1.17±0.14 mm, P<.001), without a change in lumen area (4.51±2.42 mm2 vs. 5.71±3.11mm2, P=.25).

CONCLUSIONS

This is the first study to demonstrate the feasibility of successfully obtaining vessel wall images at 3T using PS-DIR in asymptomatic patients with known variable degrees of CAD as detected by MDCT. This was achieved with a fixed subject-invariant planning of blood signal nulling. With that limitation alleviated, PS-DIR coronary wall MRI is capable of detecting arterial thickening and positive arterial remodeling at 3T in asymptomatic CAD.

Optimizing the imaging protocol for ex vivo coronary artery wall using high-resolution MRI: an experimental study on porcine and human

Objective

To optimize the MR imaging protocol for coronary arterial wall depiction in vitro and characterize the coronary atherosclerotic plaques.

Materials and Methods

MRI examination was prospectively performed in ten porcine hearts in order to optimize the MR imaging protocol. Various surface coils were used for coronary arterial wall imaging with the same parameters. Then, the image parameters were further optimized for high-resolution coronary wall imaging. The signal-noise ratio (SNR) and contrast-noise ratio (CNR) of images were measured. Finally, 8 human cadaver hearts with coronary atherosclerotic plaques were prospectively performed with MRI examination using optimized protocol in order to characterize the coronary atherosclerotic plaques.

Results

The SNR and CNR of MR image with temporomandibular coil were the highest of various surface coils. High-resolution and high SNR and CNR for ex vivo coronary artery wall depiction can be achieved using temporomandibular coil with 512 × 512 in matrix. Compared with histopathology, the sensitivity and specificity of MRI for identifying advanced plaques were: type IV-V (lipid, necrosis, fibrosis), 94% and 95%; type VI (hemorrhage), 100% and 98%; type VII (calcification), 91% and 100%; and type VIII (fibrosis without lipid core), 100% and 98%, respectively.

Conclusion

Temporomandibular coil appears to be dramatically superior to eight-channel head coil and knee coil for ex vivo coronary artery wall imaging, providing higher spatial resolution and improved the SNR. Ex vivo high-resolution MRI has capability to distinguish human coronary atherosclerotic plaque compositions and accurately classify advanced plaques.

Effects of respiratory motion on coronary wall MR imaging: a quantitative study of older adults

The aim of the present study is to assess the effects of respiratory motion on the image quality of two-dimensional (2D), free-breathing, black-blood coronary wall magnetic resonance (MR) imaging. This study was compliance with the HIPPA. With the approval of the institution review board, 230 asymptomatic participants, including 164 male patients (72.9 ± 4.4 years) and 66 female patients (72.4 ± 5.1 years), were recruited. Written informed consent was obtained. A 2D navigator (NAV)-gated, black-blood coronary wall MR imaging sequence was run on the left main artery, the left anterior descending artery and the right coronary artery. The drift of the location of the NAV and scan efficiency were compared between good (scored 2 or 3) and poor images (scored 1). Age, body weight, body weight index, heart rate, length of the rest period of cardiac motion, diaphragm excursion and breathing frequency were compared using a t test between the "successful" (having 2 or 3 good images) and "unsuccessful" cases (having 1 or 0 good images). A logistic regression model was applied to identify the contributors to good image quality. The drift of the NAV location and the scan efficiency were higher in the 411 good images compared with the 279 poor images. Minimal drift of the NAV location and low body weight were identified as independent predictors of good images after using a logistic regression model to adjust for multiple physiological and technical factors. The stability of respiratory motion significantly influences the image quality of 2D, free-breathing, black-blood coronary wall MR imaging.

Magnetic resonance coronary angiography: where are we today?

Although cardiovascular magnetic resonance allows the non-invasive and radiation free visualization of both the coronary arteries and veins, coronary vessel wall imaging is still undergoing technical development to improve diagnostic quality. Assessment of the coronary vessels is a valuable addition to the analysis of cardiac function, cardiac anatomy, viability and perfusion which magnetic resonance imaging reliably allows. However, cardiac and respiratory motion and the small size of the coronary vessels present a challenge and require several technical solutions for image optimization. Furthermore, the acquisition protocols need to be adapted to the specific clinical question. This review provides an update on the current clinical applications of cardiovascular magnetic resonance coronary angiography, recent technical advances and describes the acquisition protocols in use.

Hypercoagulability and cardiovascular disease in diabetic nephropathy

Diabetic nephropathy is the leading cause of end stage renal disease (ESRD) and an important risk factor for cardiovascular disease. Recent studies have shown that increased plasma levels of Von Willebrand factor (VWF) and reduced plasma levels of enzyme ADAMTS13 are associated with diabetic nephropathy and an increased risk of developing cardiovascular disease, suggesting that these markers of hypercoagulability may contribute to an increased risk of cardiovascular disease in diabetic patients with impaired renal function. However, it is still not clear whether VWF and ADAMTS13 are only markers of cardiovascular events or whether they play an active role in the development of these events. It is also unclear how renal injury may affect ADAMTS13 levels, leading consequently to hypercoagulability. The association of diabetic nephropathy, atherosclerotic cardiovascular disease and these hypercoagulability markers is discussed in this review. Insights on the role that renal dysfunction and other possible mechanisms may have in ADAMTS13 metabolism, leading to reduced levels of this enzyme and increased hypercoagulability are also presented.

Coronary vessel wall 3-T MR imaging with time-resolved acquisition of phase-sensitive dual inversion-recovery (TRAPD) technique: initial results in patients with risk factors for coronary artery disease

PURPOSE

To develop a technique for time-resolved acquisition of phase-sensitive dual-inversion recovery (TRAPD) coronary vessel wall magnetic resonance (MR) images, to investigate the success rate in coronary wall imaging compared with that of single-frame imaging, and to assess vessel wall thickness in healthy subjects and subjects with risk factors for coronary artery disease (CAD).

MATERIALS AND METHODS

Thirty-eight subjects (12 healthy subjects, 26 subjects with at least one CAD risk factor) provided informed consent for participation in this institutional review board-approved and HIPAA-compliant study. The TRAPD coronary vessel wall imaging sequence was developed and validated with a flow phantom. Time-resolved coronary artery wall images at three to five cine phases were obtained in all subjects. Qualitative and quantitative comparisons were made between TRAPD and conventional single-image wall measurements. Measurement reproducibility also was assessed. Statistical analysis was performed for all comparisons.

RESULTS

The TRAPD sequence successfully restored the negative polarity of lumen signal and enhanced lumen wall contrast on the cine images of the flow phantom and in all subjects. Use of three to five frames increased the success rate of acquiring at least one image of good to excellent quality from 76% in single-image acquisitions to 95% with the TRAPD sequence. The difference in vessel wall thickness between healthy subjects and subjects with CAD risk factors was significant (P < .05) with the TRAPD sequence (1.07 vs 1.46 mm, respectively; 36% increase) compared with single-frame dual inversion-recovery imaging (1.24 vs 1.55 mm, respectively; 25% increase). Intraobserver, interobserver, and interexamination agreement for wall thickness measurement were 0.98, 0.97, and 0.92, respectively.

CONCLUSION

TRAPD imaging of coronary arteries improved arterial wall visualization and quantitative assessment by increasing the success rate of obtaining good- to excellent-quality images and sections orthogonal to the longitudinal axis of the vessel. This also resulted in vessel wall thickness measurements that show a more distinct difference between healthy subjects and those with CAD risk factors.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120068/-/DC1.

Cardiovascular autonomic neuropathy and subclinical cardiovascular disease in normoalbuminuric type 1 diabetic patients

Cardiovascular autonomic neuropathy (CAN) is associated with increased mortality in diabetes. Since CAN often develops in parallel with diabetic nephropathy as a confounder, we aimed to investigate the isolated impact of CAN on cardiovascular disease in normoalbuminuric patients. Fifty-six normoalbuminuric, type 1 diabetic patients were divided into 26 with (+) and 30 without (-) CAN according to tests of their autonomic nerve function. Coronary artery plaque burden and coronary artery calcium score (CACS) were evaluated using computed tomography. Left ventricular function was evaluated using echocardiography. Blood pressure and electrocardiography were recorded through 24 h to evaluate nocturnal drop in blood pressure (dipping) and pulse pressure. In patients +CAN compared with -CAN, the CACS was higher, and only patients +CAN had a CACS >400. A trend toward a higher prevalence of coronary plaques and flow-limiting stenosis in patients +CAN was nonsignificant. In patients +CAN, left ventricular function was decreased in both diastole and systole, nondipping was more prevalent, and pulse pressure was increased compared with -CAN. In multivariable analysis, CAN was independently associated with increased CACS, subclinical left ventricular dysfunction, and increased pulse pressure. In conclusion, CAN in normoalbuminuric type 1 diabetic patients is associated with distinct signs of subclinical cardiovascular disease.

Metabolic diversity of progressive kidney disease in 325 patients with type 1 diabetes (the FinnDiane Study)

Type 1 diabetic patients with varying severity of kidney disease were investigated to create multimetabolite models of the disease process. Urinary albumin excretion rate was measured for 3358 patients with type 1 diabetes. Prospective records were available for 1051 patients, of whom 163 showed progression of albuminuria (8.3-year follow-up), and 162 were selected as stable controls. At baseline, serum lipids, lipoprotein subclasses, and low-molecular weight metabolites were quantified by NMR spectroscopy (325 samples). The data were analyzed by the self-organizing map. In cross-sectional analyses, patients with no complications had low serum lipids, less inflammation, and better glycemic control, whereas patients with advanced kidney disease had high serum cystatin-C and sphingomyelin. These phenotype extremes shared low unsaturated fatty acids (UFAs) and phospholipids. Prospectively, progressive albuminuria was associated with high UFAs, phospholipids, and IDL and LDL lipids. Progression at longer duration was associated with high HDL lipids, whereas earlier progression was associated with poor glycemic control, increased saturated fatty acids (SFAs), and inflammation. Diabetic kidney disease consists of diverse metabolic phenotypes: UFAs, phospholipids, IDL, and LDL may be important in the subclinical phase, high SFAs and low HDL suggest accelerated progression, and the sphingolipid pathway in advanced kidney injury deserves further research.

Coronary imaging with cardiovascular magnetic resonance: current state of the art

Cardiovascular magnetic resonance allows noninvasive and radiation-free visualization of both the coronary arteries and veins, with the advantage of an integrated assessment of cardiac function, viability, perfusion, and anatomy. This combined approach provides valuable integrated information for patients with coronary artery disease and patients undergoing cardiac resynchronization therapy. Moreover, magnetic resonance offers the possibility of coronary vessel wall imaging, therefore assessing the anatomy and pathology of the normal and diseased coronary vessels noninvasively. Coronary magnetic resonance angiography is challenging because of cardiac and respiratory motion and the small size and tortuous path of the coronary vessels. Several technical solutions have been developed to optimize the acquisition protocol to the specific clinical question. The aims of this review are to provide an update on current technical improvements in coronary magnetic resonance angiography, including how to optimize the acquisition protocols, and to give an overview of its current clinical application.

Accuracy of MRI to identify the coronary artery plaque: a comparative study with intravascular ultrasound

PURPOSE

To evaluate the ability of black-blood coronary arterial wall MRI to identify the coronary artery plaque, using intravascular ultrasound (IVUS) as the golden standard.

MATERIALS AND METHODS

Nineteen consecutive patients underwent IVUS and coronary artery wall MRI. Cross-sectional images were acquired on the lesion of coronary artery from the ostium to the middle segment continuously. The vessel cross-sectional area (CSA), luminal CSA, plaque burden, contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured in each slice which was then compared with the IVUS images.

RESULTS

Sixteen of 19 patients completed coronary artery MRA and wall imaging. 41 of 67 slices were found plaques on both IVUS and MRI; The maximal wall thickness, plaque burden, SNR, CNR in the coronary wall containing plaque were greater compared with the normal coronary wall (1.70 ± 0.51 versus 1.24 ± 0.24; 0.71 ± 0.13 versus 0.59 ± 0.12; 1.86 ± 0.41 versus 1.47 ± 0.23; 5.10 ± 2.21 versus 2.99 ± 1.17; respectively, P < 0.05). The matched MRI and IVUS showed good correlation for vessel CSA (16.77 ± 10.67 versus 16.97 ± 8.36; r = 0.79; P < 0.01), luminal CSA (5.18 ± 5.01 versus 7.13 ± 5.14; r = 0.88; P < 0.01), plaque burden (0.71 ± 0.13 versus 0.59 ± 0.15; r = 0.67; P < 0.01). in segments containing plaques, especially the luminal CSA were strongly correlated.

CONCLUSION

MRI coronary artery wall imaging can identify coronary plaque in the proximal segments. It also has the potential to assess coronary artery size.

Determination of edema in porcine coronary arteries by T2 weighted cardiovascular magnetic resonance

BACKGROUND

Inflammation plays a pivotal role in all stages of atherosclerosis. Since edema is known to be an integral part of inflammation, a noninvasive technique that can identify edema in the coronary artery wall may provide unique information regarding plaque activity. In this study, we aimed to determine whether edema induced in porcine coronary arteries by balloon injury could be reliably detected by cardiovascular magnetic resonance (CMR) using a water sensitive T2-weighted short tau inversion recovery sequence (T2-STIR). We also aimed to compare these results to those of conventional T2-weighted (T2W) imaging.

METHODS

Edema was induced in the proximal left anterior descending (LAD) coronary artery wall in seven pigs by balloon injury. At baseline, and 1-10 days (average four) post injury, the proximal LAD was assessed by water sensitive T2-STIR and conventional T2W sequences in cross-sectional planes. CMR images were matched to histopathology, validated against Evans blue as a marker of increased vessel wall permeability, and correlated with the arterial amount of fibrinogen used as an edema surrogate marker.

RESULTS

Post injury, the T2-STIR images of the injured LAD vessel wall showed a significant 72%, relative signal intensity (SI) increase compared with baseline (p = 0.028). Using a threshold value of SI 7 SD above the average SI of the myocardium, T2-STIR detected edema in the vessel wall (i.e. enhancement) with a sensitivity of 100 and a specificity of 71. Twelve out of the 14 (86%) T2-STIR images displaying coronary artery wall enhancement also showed Evans blue uptake in the corresponding histology. The relative signal intensity showed a linear correlation with the amount of fibrinogen detected on the corresponding histopathology (ρ = 0.750, p = 0.05). The conventional T2W images did not show significant changes in SI post injury.

CONCLUSION

T2-STIR CMR enabled detection of coronary artery wall edema and could therefore be a non-invasive diagnostic tool for evaluation of inflammatory coronary artery wall activity.

Imaging as an End Point in Ischemia Trials

Imaging of cardiac function and anatomy has advanced at an exponential rate over the past two decades. Our ability to quantitatively assess the degree of myocardial ischemia and accurately define the vascular anatomy using noninvasive techniques is greater than ever before. Current advances is cardiac imaging are allowing us to more safely assess patients for myocardial ischemia and better understand the prognostic implications of our findings. This review summarizes the current state of knowledge in cardiac imaging for the assessment of cardiac ischemia with a focus on the use of cardiac MRI.