Jens Vogel-Claussen

Normal values for cardiovascular magnetic resonance in adults and children

Morphological and functional parameters such as chamber size and function, aortic diameters and distensibility, flow and T1 and T2* relaxation time can be assessed and quantified by cardiovascular magnetic resonance (CMR). Knowledge of normal values for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. In this review, we present normal reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques and sequences.

Left ventricular papillary muscle mass : Relationship to left ventricular mass and volumes by magnetic resonance imaging

Objective: To evaluate the effect of papillary muscle mass on the calculation of left ventricular (LV) function and mass and to determine the relationship between papillary muscle mass with body size and sex. Methods: Cardiac magnetic resonance imaging examinations from 50 men and 50 women were randomly selected from the Multi-Ethnic Study of Atherosclerosis database. The contours of the papillary muscles were traced manually, and the LV wall contours were outlined semiautomatically based on short-axis images. Papillary muscle mass, LV mass, and volumes were calculated. Results: Inclusion of the papillary muscles results in significantly higher total LV mass values (P < 0.001) and lower end-diastolic volume values (P < 0.001) compared with measurements excluding papillary muscles from the LV mass. Papillary muscle mass accounts for 8.9% of the total LV mass and is correlated with LV wall mass (r = 0.81, P < 0.001). Conclusion: Papillary muscle mass significantly affects LV volumes and mass determined by cine magnetic resonance imaging.

Bisphosphonate Use and Prevalence of Valvular and Vascular Calcification in Women: MESA (The Multi-Ethnic Study of Atherosclerosis)

OBJECTIVES the aim of this study was to determine whether nitrogen-containing bisphosphonate (NCBP) therapy is associated with the prevalence of cardiovascular calcification. BACKGROUND cardiovascular calcification correlates with atherosclerotic disease burden. Experimental data suggest that NCBP might limit cardiovascular calcification, which has implications for disease prevention. METHODS the relationship of NCBP use to the prevalence of aortic valve, aortic valve ring, mitral annulus, thoracic aorta, and coronary artery calcification (AVC, AVRC, MAC, TAC, and CAC, respectively) detected by computed tomography was assessed in 3,710 women within the MESA (Multi-Ethnic Study of Atherosclerosis) with regression modeling. RESULTS Analyses were age-stratified, because of a significant interaction between age and NCBP use (interaction p values: AVC p < 0.0001; AVRC p < 0.0001; MAC p = 0.002; TAC p < 0.0001; CAC p = 0.046). After adjusting for age; body mass index; demographic data; diabetes; smoking; blood pressure; cholesterol levels; and statin, hormone replacement, and renin-angiotensin inhibitor therapy, NCBP use was associated with a lower prevalence of cardiovascular calcification in women ≥ 65 years of age (prevalence ratio: AVC 0.68 [95% confidence interval (CI): 0.41 to 1.13]; AVRC 0.65 [95% CI: 0.51 to 0.84]; MAC 0.54 [95% CI: 0.33 to 0.93]; TAC 0.69 [95% CI: 0.54 to 0.88]; CAC 0.89 [95% CI: 0.78 to 1.02]), whereas calcification was more prevalent in NCBP users among the 2,181 women <65 years of age (AVC 4.00 [95% CI: 2.33 to 6.89]; AVRC 1.92 [95% CI: 1.42 to 2.61]; MAC 2.35 [95% CI: 1.12 to 4.84]; TAC 2.17 [95% CI: 1.49 to 3.15]; CAC 1.23 [95% CI: 0.97 to 1.57]). CONCLUSIONS among women in the diverse MESA cohort, NCBPs were associated with decreased prevalence of cardiovascular calcification in older subjects but more prevalent cardiovascular calcification in younger ones. Further study is warranted to clarify these age-dependent NCBP effects.

Myocardial delayed enhancement in pulmonary hypertension: pulmonary hemodynamics, right ventricular function, and remodeling.

OBJECTIVE The purpose of this study was to assess predictors of MRI-identified septal delayed enhancement mass at the right ventricular (RV) insertion sites in relation to RV remodeling, altered regional mechanics, and pulmonary hemodynamics in patients with suspected pulmonary hypertension (PH). SUBJECTS AND METHODS Thirty-eight patients with suspected PH were evaluated with right heart catheterization and cardiac MRI. Ten age- and sex-matched healthy volunteers acted as controls for MRI comparison. Septal delayed enhancement mass was quantified at the RV insertions. Systolic septal eccentricity index, global RV function, and remodeling indexes were quantified with cine images. Peak systolic circumferential and longitudinal strain at the sites corresponding to delayed enhancement were measured with conventional tagging and fast strain-encoded MRI acquisition, respectively. RESULTS PH was diagnosed in 32 patients. Delayed enhancement was found in 31 of 32 patients with PH and in one of six patients in whom PH was suspected but proved absent (p = 0.001). No delayed enhancement was found in controls. Delayed enhancement mass correlated with pulmonary hemodynamics, reduced RV function, increased RV remodeling indexes, and reduced eccentricity index. Multiple linear regression analysis showed RV mass index was an independent predictor of total delayed enhancement mass (p = 0.017). Regional analysis showed delayed enhancement mass was associated with reduced longitudinal strain at the basal anterior septal insertion (r = 0.6, p < 0.01). Regression analysis showed that basal longitudinal strain remained an independent predictor of delayed enhancement mass at the basal anterior septal insertion (p = 0.02). CONCLUSION In PH, total delayed enhancement burden at the RV septal insertions is predicted by RV remodeling in response to increased afterload. Local fibrosis mass at the anterior septal insertion is associated with reduced regional longitudinal contractility at the base.

Left ventricular structure and function in patients with rheumatoid arthritis, as assessed by cardiac magnetic resonance imaging

OBJECTIVE Heart failure is a major contributor to cardiovascular morbidity and mortality in patients with rheumatoid arthritis (RA), but little is known about myocardial structure and function in this population. This study was undertaken to assess the factors associated with progression to heart failure in patients with RA. METHODS With the use of cardiac magnetic resonance imaging, measures of myocardial structure and function were assessed in men and women with RA enrolled in the Evaluation of Subclinical Cardiovascular Disease and Predictors of Events in Rheumatoid Arthritis study, a cohort study of subclinical cardiovascular disease in patients with RA, in comparison with non-RA control subjects from a cohort enrolled in the Baltimore Multi-Ethnic Study of Atherosclerosis. RESULTS Measures of myocardial structure and function were compared between 75 patients with RA and 225 frequency-matched controls. After adjustment for confounders, the mean left ventricular mass was found to be 26 gm lower in patients with RA compared with controls (P < 0.001), an 18% difference. In addition, the mean left ventricular ejection fraction, cardiac output, and stroke volume were modestly lower in the RA group compared with controls. The mean left ventricular end systolic and end diastolic volumes did not differ between the groups. In patients with RA, higher levels of anti-cyclic citrullinated peptide (anti-CCP) antibodies and current use of biologic agents, but not other measures of disease activity or severity, were associated with significantly lower adjusted mean values for the left ventricular mass, end diastolic volume, and stroke volume, but not with ejection fraction. The combined associations of anti-CCP antibody level and biologic agent use with myocardial measures were additive, without evidence of interaction. CONCLUSION These findings suggest that the progression to heart failure in RA may occur through reduced myocardial mass rather than hypertrophy. Both modifiable and nonmodifiable factors may contribute to lower levels of left ventricular mass and volume.

Right and Left Ventricular Myocardial Perfusion Reserves Correlate with Right Ventricular Function and Pulmonary Hemodynamics in Patients with Pulmonary Arterial Hypertension

PURPOSE To evaluate the relationships of right ventricular (RV) and left ventricular (LV) myocardial perfusion reserves with ventricular function and pulmonary hemodynamics in patients with pulmonary arterial hypertension (PAH) by using adenosine stress perfusion cardiac magnetic resonance (MR) imaging. MATERIALS AND METHODS This HIPAA-compliant study was institutional review board approved. Twenty-five patients known or suspected to have PAH underwent right heart catheterization and adenosine stress MR imaging on the same day. Sixteen matched healthy control subjects underwent cardiac MR imaging only. RV and LV perfusion values at rest and at adenosine-induced stress were calculated by using the Fermi function model. The MR imaging-derived RV and LV functional data were calculated by using dedicated software. Statistical testing included Kruskal-Wallis tests for continuous data, Spearman rank correlation tests, and multiple linear regression analyses. RESULTS Seventeen of the 25 patients had PAH: 11 with scleroderma-associated PAH, and six with idiopathic PAH. The remaining eight patients had scleroderma without PAH. The myocardial perfusion reserve indexes (MPRIs) in the PAH group (median RV MPRI, 1.7 [25th-75th percentile range, 1.3-2.0]; median LV MPRI, 1.8 [25th-75th percentile range, 1.6-2.1]) were significantly lower than those in the scleroderma non-PAH (median RV MPRI, 2.5 [25th-75th percentile range, 1.8-3.9] [P = .03]; median LV MPRI, 4.1 [25th-75th percentile range, 2.6-4.8] [P = .0003]) and control (median RV MPRI, 2.9 [25th-75th percentile range, 2.6-3.6] [P < .01]; median LV MPRI, 3.6 [25th-75th percentile range, 2.7-4.1] [P < .01]) groups. There were significant correlations between biventricular MPRI and both mean pulmonary arterial pressure (mPAP) (RV MPRI: ρ = -0.59, Bonferroni P = .036; LV MPRI: ρ = -0.79, Bonferroni P < .002) and RV stroke work index (RV MPRI: ρ = -0.63, Bonferroni P = .01; LV MPRI: ρ = -0.75, Bonferroni P < .002). In linear regression analysis, mPAP and RV ejection fraction were independent predictors of RV MPRI. mPAP was an independent predictor of LV MPRI. CONCLUSION Biventricular vasoreactivity is significantly reduced with PAH and inversely correlated with RV workload and ejection fraction, suggesting that reduced myocardial perfusion reserve may contribute to RV dysfunction in patients with PAH.

Quality Initiatives MR Imaging in Patients at Risk for Developing Nephrogenic Systemic Fibrosis: Protocols, Practices, and Imaging Techniques to Maximize Patient Safety

Nephrogenic systemic fibrosis (NSF) is a rare but potentially debilitating or even fatal fibrosing condition that most often affects the skin but is now also recognized to involve multiple organs. The first report on NSF was published in 1997, and there is mounting evidence that this condition is associated with renal failure and the administration of large amounts of gadolinium. Although gadolinium-enhanced magnetic resonance (MR) imaging was once considered one of the safer imaging procedures, concerns over NSF have led the radiology community to rethink its imaging practices. Several noncontrast angiographic techniques based on fast spin-echo, gradient-echo, phase-contrast, and inversion-recovery principles are currently available. These techniques allow MR angiography to be performed safely, even in patients at risk for developing NSF. When use of gadolinium-based contrast material is necessary for diagnosis, it is possible to reduce total gadolinium administration through the use of agents with higher relaxivity, time-resolved imaging, high-field-strength magnets, and body compression devices. Management of NSF also requires an understanding of the risk factors of this disease and developing an institutional policy for identifying and testing at-risk patients.

Endothelial microparticles in mild chronic obstructive pulmonary disease and emphysema. The Multi-Ethnic Study of Atherosclerosis Chronic Obstructive Pulmonary Disease study.

RATIONALE Basic research implicates alveolar endothelial cell apoptosis in the pathogenesis of chronic obstructive pulmonary disease (COPD) and emphysema. However, information on endothelial microparticles (EMPs) in mild COPD and emphysema is lacking. OBJECTIVES We hypothesized that levels of CD31(+) EMPs phenotypic for endothelial cell apoptosis would be elevated in COPD and associated with percent emphysema on computed tomography (CT). Associations with pulmonary microvascular blood flow (PMBF), diffusing capacity, and hyperinflation were also examined. METHODS The Multi-Ethnic Study of Atherosclerosis COPD Study recruited participants with COPD and control subjects age 50-79 years with greater than or equal to 10 pack-years without clinical cardiovascular disease. CD31(+) EMPs were measured using flow cytometry in 180 participants who also underwent CTs and spirometry. CD62E(+) EMPs phenotypic for endothelial cell activation were also measured. COPD was defined by standard criteria. Percent emphysema was defined as regions less than -950 Hounsfield units on full-lung scans. PMBF was assessed on gadolinium-enhanced magnetic resonance imaging. Hyperinflation was defined as residual volume/total lung capacity. Linear regression was used to adjust for potential confounding factors. MEASUREMENTS AND MAIN RESULTS CD31(+) EMPs were elevated in COPD compared with control subjects (P = 0.03) and were notably increased in mild COPD (P = 0.03). CD31(+) EMPs were positively related to percent emphysema (P = 0.045) and were inversely associated with PMBF (P = 0.047) and diffusing capacity (P = 0.01). In contrast, CD62E(+) EMPs were elevated in severe COPD (P = 0.003) and hyperinflation (P = 0.001). CONCLUSIONS CD31(+) EMPs, suggestive of endothelial cell apoptosis, were elevated in mild COPD and emphysema. In contrast, CD62E(+) EMPs indicative of endothelial activation were elevated in severe COPD and hyperinflation.

Pulmonary Microvascular Blood Flow in Mild Chronic Obstructive Pulmonary Disease and Emphysema. The MESA COPD Study

RATIONALE Smoking-related microvascular loss causes end-organ damage in the kidneys, heart, and brain. Basic research suggests a similar process in the lungs, but no large studies have assessed pulmonary microvascular blood flow (PMBF) in early chronic lung disease. OBJECTIVES To investigate whether PMBF is reduced in mild as well as more severe chronic obstructive pulmonary disease (COPD) and emphysema. METHODS PMBF was measured using gadolinium-enhanced magnetic resonance imaging (MRI) among smokers with COPD and control subjects age 50 to 79 years without clinical cardiovascular disease. COPD severity was defined by standard criteria. Emphysema on computed tomography (CT) was defined by the percentage of lung regions below -950 Hounsfield units (-950 HU) and by radiologists using a standard protocol. We adjusted for potential confounders, including smoking, oxygenation, and left ventricular cardiac output. MEASUREMENTS AND MAIN RESULTS Among 144 participants, PMBF was reduced by 30% in mild COPD, by 29% in moderate COPD, and by 52% in severe COPD (all P < 0.01 vs. control subjects). PMBF was reduced with greater percentage emphysema-950HU and radiologist-defined emphysema, particularly panlobular and centrilobular emphysema (all P ≤ 0.01). Registration of MRI and CT images revealed that PMBF was reduced in mild COPD in both nonemphysematous and emphysematous lung regions. Associations for PMBF were independent of measures of small airways disease on CT and gas trapping largely because emphysema and small airways disease occurred in different smokers. CONCLUSIONS PMBF was reduced in mild COPD, including in regions of lung without frank emphysema, and may represent a distinct pathological process from small airways disease. PMBF may provide an imaging biomarker for therapeutic strategies targeting the pulmonary microvasculature.

Pulmonary Arterial Hypertension: MR Imaging-derived First-Pass Bolus Kinetic Parameters Are Biomarkers for Pulmonary Hemodynamics, Cardiac Function, and Ventricular Remodeling

PURPOSE To prospectively compare contrast material-enhanced (CE) magnetic resonance (MR) imaging-derived right-to-left ventricle pulmonary transit time (PTT), left ventricular (LV) full width at half maximum (FWHM), and LV time to peak (TTP) between patients with pulmonary arterial hypertension (PAH) and healthy volunteers and to correlate these measurements with survival markers in patients with PAH. MATERIALS AND METHODS This HIPAA-compliant study received institutional review board approval. Written informed consent was obtained from all participants. Forty-three patients (32 with PAH [29 women; median age, 55.4 years], 11 with scleroderma but not PAH [seven women; median age, 58.9 years]) underwent right-sided heart catheterization and 3-T CE cardiac MR imaging. Eighteen age- and sex-matched healthy control subjects (12 women; median age, 51.7 years) underwent only CE MR imaging. A short-axis saturation-recovery gradient-echo section was acquired in the basal third of both ventricles, and right-to-left-ventricle PTT, LV FWHM, and LV TTP were calculated. Statistical analysis included Kruskal-Wallis test, Wilcoxon rank sum test, Spearman correlation coefficient, multiple linear regression analysis, and Lin correlation coefficient analysis. RESULTS Patients had significantly longer PTT (median, 8.2 seconds; 25th-75th percentile, 6.9-9.9 seconds), FWHM (median, 8.2 seconds; 25th-75th percentile, 5.7-11.4 seconds), and TTP (median, 4.8 seconds; 25th-75th percentile, 3.9-6.5 seconds) than did control subjects (median, 6.4 seconds; 25th-75th percentile, 5.7-7.1 seconds; median, 5.2 seconds; 25th-75th percentile, 4.1-6.1 seconds; median, 3.2 seconds; 25th-75th percentile, 2.8-3.8 seconds, respectively; P < .01 for each) and subjects with scleroderma but not PAH (median, 6.5 seconds; 25th-75th percentile, 5.6-7.0 seconds; median, 5.0 seconds; 25th-75th percentile, 4.0-7.3 seconds; median, 3.6 seconds; 25th-75th percentile, 2.7-4.0 seconds, respectively; P < .02 for each). PTT, LV FWHM, and LV TTP correlated with pulmonary vascular resistance index (P < .01), right ventricular stroke volume index (P ≤ .01), and pulmonary artery capacitance (P ≤ .02). In multiple linear regression models, PTT, FWHM, and TTP were associated with mean pulmonary arterial pressure and cardiac index. CONCLUSION CE MR-derived PTT, LV FWHM, and LV TTP are noninvasive compound markers of pulmonary hemodynamics and cardiac function in patients with PAH. Their predictive value for patient outcome warrants further investigation.