SSFP Cine Sequences Research Articles

Age- and gender-related normal left ventricular deformation assessed by cardiovascular magnetic resonance feature tracking.

BackgroundAssessment of left (LV) ventricular function is one of the most important tasks of cardiovascular magnetic resonance (CMR). Impairment of LV deformation is a strong predictor of cardiovascular outcome in various cardiac diseases like ischemic heart disease or cardiomyopathies. The aim of the study was to provide reference values for myocardial deformation derived from the CMR feature tracking imaging (FTI) algorithm in a reference population of healthy volunteers.MethodsFTI was applied to standard short axis and 2-, 3- and 4-chamber views of vector-ECG gated CMR cine SSFP sequences of 150 strictly selected healthy volunteers (75 male/female) of three age tertiles (mean age 45.8yrs). Global peak and mean radial, circumferential and longitudinal endo- and myocardial systolic strain values as well as early diastolic strain rates were measured using FTI within a standard protocol on a 1.5T whole body MR scanner.ResultsGlobal peak systolic values were 36.3 ± 8.7% for radial, −27.2 ± 4.0% for endocardial circumferential, −21.3 ± 3.3% for myocardial circumferential, −23.4 ± 3.4% for endocardial longitudinal and −21.6 ± 3.2% for myocardial longitudinal strain. Global peak values were -2.1 ± 0.5s−1 for radial, 2.1 ± 0.6s−1 for circumferential endocardial, 1.7 ± 0.5s−1 for circumferential myocardial, 1.8 (1.5-2.2)s−1 for longitudinal endocardial, 1.6 (1.4-2.0)s−1 for longitudinal myocardial early diastolic strain rates. Men showed a higher radial strain than women whereas the circumferential and longitudinal strains were lower resulting in less negative values. Circumferential and longitudinal strain rates were significantly higher in female subjects. Radial strain increased significantly with age whereas the diastolic function measured by the radial, circumferential and longitudinal strain rates showed a decrease.The coefficients of variation determined in ten further subjects, who underwent two CMR examinations within 12 days, were −4.8% for circumferential and −4.5% for longitudinal endocardial mean strains.ConclusionsMyocardial deformation analysis using FTI is a novel technique and robust when applied to standard cine CMR images providing the possibility of a reliable, objective quantification of global LV deformation. Since strain values and strain rates differed partly between genders as well as between age groups, the application of specific reference values as provided by this study is recommendable.

Pericardial Effusion Is a Marker of Increased Mortality in Thalassemia Major Patients

Introduction. In different types of not-hematological diseases the presence of a small pericardial effusion (PE) was associated with worse survival even after adjustment for patient characteristics, suggesting that it is a marker of underlying disease.In thalassemia major (TM) pericardial effusion was shown to be one of the manifestations of heart disease but its potential prognostic importance has never been investigated in the modern era. Cardiovascular Magnetic Resonance (CMR) by cine SSFP sequences was demonstrated to be extremely sensitive to even a small amount of PE.This is the first prospective study evaluating if the presence of pericardial effusion is associated with increased mortality in TM.Methods. 1259 patients (648 females, mean age 31.02 ± 8.64 years) enrolled in the Myocardial Iron Overload in Thalassemia (MIOT) were prospectively followed from their first Magnetic Resonance Imaging (MRI) scan. CMR was used to quantify myocardial iron (MIO) overload by a multislice multiecho T2* approach and to assess biventricular function parameters and to detect PE by cine SSFP sequences.Results. PE was present in 25 (2.0%) patients.Patients with and without PE were comparable for age and ratio of men/women. At the baseline, the percentage of patients with MIO (global heart T2* value < 20 ms) was comparable between patients with and without PE (12.0 % vs 28.7%; P=0.074) and left ventricular and right ventricular ejection fractions were not significantly different between the two groups.Mean follow-up (FU) time was 44.55 ± 20.35 months and there were 15 deaths.Mortality was greater for patients with PE compared to those without an effusion (8.0% vs 1.1%, P=0.034).PE was a significant predictive factor for death (hazard ratio-HR=12.64, 95%CI=2.78-57.42, P=0.001). PE remained a significant prognosticator for death also in a multivariate model including MIO ms (PE: HR=17.36, 95%CI=3.65-82.62, P<0.0001and global heart T2* < 20 ms: HR=3.07, 95%CI=1.07-8.75, P=0.036).Conclusions. PE is quite rare in TM patients and it is not related to myocardial iron overload. An important role in the development of PE could be played by the 'iron-induced’ pericardial siderosis but, due to the limitations of the current non-invasive CMR techniques, we were not able to address this issue.PE was found to be a strong predictor for death, independently by the presence of myocardial iron overload. The non-invasive diagnosis of pericardial effusion is important for a more complete definition of the cardiac involvement of TM patients. The increased risk of death associated with PE may be used along with other clinical characteristics when estimating a patient’s prognosis and monitoring. DisclosuresPepe:Chiesi: Speakers Bureau; ApoPharma Inc.: Speakers Bureau; Novartis: Speakers Bureau.

Comparison of magnetic resonance feature tracking with harmonic phase imaging analysis (CSPAMM) for assessment of global and regional diastolic function

AimsComplex post-processing is required for strain-derived assessment of diastolic dysfunction (DD) using CMR-tagging (TAG). Feature-tracking (FT), allows for rapid systolic strain assessment using conventional steady-state free precession (SSFP)-Cine sequences. Aim of this study was to investigate whether FT may be employed for the clinically applicable quantification of DD. Methods and Results40 individuals (20 patients with DD I-III°, 20 controls) were investigated. CSPAMM and SSFP-Cine sequences were acquired in identical short-axis locations. Global and regional early diastolic strain rate (EDSR), peak diastolic strain rate (PDSR), twist, untwist and torsion were calculated from tagged and SSFP-Cine datasets. DD indices were compared, intra- as well inter-observer variability assessed. Resultsfor global EDSR correlated strongly (r=0.94), revealed good agreement and no significant differences between both methods. Correlation for regional EDSR was lower, results differed significantly in the anterior wall (p<0.05). Correlation for PDSR was moderate (r=0.63), results in the healthy control group differed significantly (p<0.05). FT derived rotational indices correlated poorly with TAG (twist: r=0.28; untwist: r=0.02; torsion: r=0.26), subgroup analysis revealed significant differences (p<0.05). Intra- and inter-observer variability for FT derived global EDSR and PDSR were comparable to TAG, but significantly higher for regional EDSR and rotational indices. ConclusionFT derived global EDSR allows for rapid clinical determination of diastolic dysfunction, revealing good agreement with TAG and low intra- as well as interobserver variability. However, TAG analysis not only yields higher accuracy and reproducibility of global- and regional diastolic strain, but also delivers reliable information about diastolic rotational and untwisting dynamics.

Cardiac magnetic resonance strain imaging in systemic light chain amyloidosis

Background Systemic light chain amyloidosis (AL) is associated with a high cardiovascular morbidity and mortality. Cardiovascular involvement and determination of prognosis is underestimated by standard imaging parameters. Recently, cardiac deformation analysis of global circumferential and longitudinal strain has been shown to have great clinical impact on the assessment of prognosis and survival in this rare disease. For further analysis we applied the novel non-invasive post-processing feature tracking imaging (FTI) algorithm on pre-acquired regular CMR SSFP images in healthy volunteers and in patients with AL and sought to investigate different strain patterns. Methods 87 patients (mean age 60 ± 11 years) with biopsy proven systemic AL were scanned on a clinical 1.5 T CMR scanner (Philips Achieva). Short axis slices covering entirely both ventricles as well as 2-, 3- and 4-chamber views were acquired using standard SSFP-sequences before initiation of any specific pharmaceutical AL therapies. The control group consisted of 47 healthy subjects (mean age 59 ± 5 years). Besides the standard CMR parameters for volumes, ejection fraction, myocardial mass and wall thickness we measured the circumferential and the longitudinal strain on cine SSFP images by the application of the post-processing FTI algorithm. Results In patients with AL mean longitudinal strain from the four chamber view (-15.9 ± 5.6% vs -21.3 ± 4%, p < 0.05) as well as midventricular mean circumferential strain (-22.8 ± 6.7% vs -25.1 ± 4.5%, p < 0.05) were significantly reduced compared to healthy subjects. Global circumferential strain and global longitudinal strain correlated with left ventricular ejection fraction (r = -0.61, p < 0.05; r = -0.62, p < 0.05). In the subgroup analysis of AL patients with a mean wall thickness less than 12 mm global longitudinal strain showed significantly reduced values in comparison to healthy control subjects (-18.3 ± 5.3% vs -21.3 ± 4%, p < 0.05), whereas global circumferential strain did not show a significant difference. Patients with an ejection fraction ≥55% already had reduced global longitudinal strains (-18 ± 4.7% vs -21.3 ± 4%, p < 0.05), again global circumferential strain did not show a significant difference. Conclusions FTI strain analysis derived from regular cine SSFP sequences offers the possibility for a fast quantitative assessment of myocardial strain imaging patterns without additional and time-consuming strain imaging sequences. FTI strain analysis provides important insight into the disturbed contraction in AL. Further investigations are necessary to analyze the impact of this new method on the prediction of clinical outcome in AL patients. Funding None.

Navigator gated flow sensitive gradient echo sequence for quantification of aortic valve regurgitation

Background Exact quantification of aortic valve regurgitation is a challenge. Patients are typically asymptomatic and echocardiography is unreliable in certain conditions, particularly in eccentric regurgitation jets. Cardiac magnetic resonance (CMR) is a valuable alternative in this situation, but the use of conventional sequences without respiration correction is limited by motion artifacts and long acquisition times caused by necessary signal averaging. Novel navigator gated flow sensitive gradient echo sequence avoid motion artifacts caused by respiration and in addition allow for a higher temporal resolution eventually leading to more reliable results. Methods On 31 patients with varying degrees of aortic regurgitation we performed both standard (StdSeq) and navigator gated (NavSeq) flow sensitive gradient echo sequences. Primary parameter was the regurgitation fraction defined as the quotient of anterograde and retrograde flow over a cross section of the ascendent aorta just above the maximal excursion of the aortic leaflets. Since a gold standard for quantification of aortic regurgitation is missing, we correlated these values with the enddiastolic volume of the left ventricle (LVEDV) assessed by a contiguous stack short axis cine-SSFP sequences. This parameter is directly influenced by the regurgitant volume. For comparison we

Cardiovascular magnetic resonance assessment of aortic root dilatation in adult patients after tetralogy of fallot repair

Purpose: Cardiovascular magnetic resonance (CMR) is an important tool in the follow-up of repaired tetralogy of Fallot (ToF). The dilatation of the aortic root (Ao dil) with risk of aneurysm and dissection is a recognized complication. We aimed to find possible predictors of Ao dil late after ToF repair. Methods: We included patients (pts) aged ≥ 18 years and we measured the maximal absolute diameter of the aortic root at the level of the sinuses of Valsalva (AoD), assessed by CMR, using SSFP cine sequences and angiography. We defined two groups: group 1 - with Ao dil (AoD ≥ 38 mm) and group 2 - without Ao dil (AoD < 38 mm). The CMR protocol included the evaluation of biventricular volumes and systolic function, and degree of pulmonary regurgitation. Exclusion criteria were: Associated heart disease congenital or acquired, genetic syndromes, unrepaired ToF, pregnancy, claustrophobia and contraindications for CMR. Results: We included 53 consecutive pts from March 2011 till December 2012 (mean age 32±10 years; 62% female); 46 pts (87%) were asymptomatic. The mean follow-up time since ToF repair was 23±7 years. In 29 pts (55%) an aortopulmonary (AP) shunt was done prior to complete ToF repair, with a median interval of 3 years. In 17 pts complete repair used a transannular patch. In 10 pts (19%; 9 male) we identified Ao dil. Only 3 out of 10 pts with right aortic arch had Ao dil. Male gender (p<0.0001), older age (39±12 vs 30±9 years; p=0.014), and higher body surface area (BSA 1.92±0.11 vs 1.65±0.19 m2; p<0.0001), left ventricle end-diastolic volume (LVEDV 170±41 vs 124±29 mL; p<0.0001), LVEDV indexed to BSA (LVEDV index 88±19 vs 75±14 mL/m2; p=0.023), left ventricle end-systolic volume (LVESV 76±26 vs 51±17 mL; p=0.022), LVESV indexed to BSA (39±12 vs 31±9 mL/m2; p=0.024) and left ventricle mass indexed to BSA (60±14 vs 52±9 g/m2; p<0.0001) were associated with Ao dil. None of the surgical variables studied (previous AP shunt, transannular patch, time to AP shunt, time between AP shunt and complete repair, time to complete repair) were significantly different between group 1 and 2. In multivariate analysis male gender was the only independent predictor of Ao dil (odds ratio 27.42, 95% confidence interval 1.95-386.48; p=0.014), after adjusting for age, previous AP shunt, follow-up time since ToF surgical repair and for LVEDV index. Conclusions: In this study male gender was the only independent predictor of aortic root dilatation late after ToF repair. In this context, CMR can be used in the screening of pts at risk of late Ao dil and therefore can contribute to prevent its potential complications.

Detection of Cardiovascular Disease in Elite Athletes Using Cardiac Magnetic Resonance Imaging

Sudden cardiac death [SCD] in competitive athletes is caused by a diverse set of cardiovascular diseases such as hypertrophic and dilated cardiomyopathy [HCM/DCM], myocarditis, coronary anomalies or even coronary artery disease. In order to identify potential risk factors responsible for SCD, elite athletes underwent cardiac magnetic resonance [CMR] imaging. 73 male [M] and 22 female [F] athletes (mean age 35.2 ± 11.4 years) underwent CMR imaging. ECG-gated breath-hold cine SSFP sequences were used for the evaluation of wall motion abnormalities and myocardial hypertrophy as well as for quantitative analysis (left and right ventricular [LV, RV] end-diastolic and end-systolic volume [EDV, ESV], stroke volume [SV], ejection fraction [EF] and myocardial mass [MM]). Furthermore, left and right atrial sizes were assessed by planimetry and delayed enhancement imaging was performed 10 minutes after the application of contrast agent. Coronary arteries were depicted using free-breathing Flash-3 D MR angiography. The quantitative analyses showed eccentric hypertrophy of the left ventricle (remodeling index [MM/LV-EDV]: M 0.75, F 0.665), enlargement of the RV volumes (RV-EDV: M 122.6 ± 19.0 ml/m², F 99.9 ± 7.2 ml/m²) and an increased SV (LV-SV: M 64.7 ± 10.0 ml/m², F 56.5 ± 5.7 ml/m²; RV-SV; M 66.7 ± 10.4 ml/m², F 54.2 ± 7.1 ml/m²). Abnormal findings were detected in 6 athletes (6.3 %) including one benign variant of coronary anomaly and abnormal late gadolinium enhancement in 2 cases. None of the athletes showed wall motion abnormalities or signs of myocardial ischemia. CMR imaging of endurance athletes revealed abnormal findings in more than 5 % of the athletes. However, the prognostic significance remains unclear. Thus, cardiac MRI cannot be recommended as a routine examination in the care of athletes.

Comparison of feature tracking with harmonic phase imaging analysis for the assessment of diastolic dysfunction

Background Diastolic dysfunction (DD) is common in patients with cardiovascular disease. Current cardiac magnetic resonance techniques for assessment of DD require the acquisition of tagged imaging sequences, and complex post-processing. A new post-processing software allows for rapid strain assessment using feature tracking analysis (FT) (TomTec, Diogenes Software, Germany) based on conventional steady-state free precession (SSFP)-Cine sequences. The aim of this study was to compare tagging (TAG) with FT for assessment of diastolic function in patients with DD and healthy controls. Methods 20 healthy volunteers and 10 patients with echocardiographic diagnosed DD Grade II-III were investigated by the 2 techniques. Cardiovascular magnetic resonance imaging (Philips Intera 1.5T) using CSPAMM and SSFP-Cine sequences was performed for matched midventricular short-axis slices. Each modality was analyzed offline using dedicated post-processing software (Tag Track, Gyrotools, CH for CSPAMM and TomTec for SSFP-Cine) and early-diastolic strain rate (EDSr) was calculated from both datasets. EDSr derived from CSPAMM and SSFP-Cine data were compared and inter-observer and intra-observer variability assessed using Bland-Altman analysis and Pearson correlation coefficient. Results For all measurements FT EDSr (78.15+/- 17.17 s -1 )w as highly correlated with TAG EDSr (76.71+/- 17.45s -1 ), Bland-Altman analyses for method comparison yielded a mean difference of 1.4 (95% CI: 0.0 to 2.9). Limits of agreement (+/- 1.96 SD) were -14.9 and 12.0. In patients with DD FT EDSr (61.40+/- 15.60s -1 )w as not significantly different to TAG EDSr (57.60+/- 12.30s -1 ) (p=ns). The same was found in the control group FT EDSr (86.52+/- 10.55s -1 ) and TAG (86.27+/- 10.31s -1 ) (p=ns). Intra-observer variability yielded a mean difference of 1.2+/- 4.9 (FT) and 0.9+/- 3.5 (TAG). Inter-observer variability displayed a mean difference of 2.8+/- 5.84 (FT) and 0.3+/- 3.7 (TAG). Pearson correlation coefficient was (0.96 (FT); 0.97 (TAG)) for intra-observer variability and (0.94 (FT); 0.97 (TAG)) for inter-observer variability.

Reference values for right atrial and right ventricular morphology and function using cardiovascular magnetic resonance imaging

Background The right ventricular (RV) morphology and function are important parameters for the diagnosis of cardiopulmonary diseases and serve as predictors for the longterm outcome. To date there are little data about right heart characteristics due to its complex anatomy. Since cardiac magnetic resonance (CMR) is the gold-standard for the evaluation of left and right cardiac anatomy and function we sought to investigate and provide reference values for the entire right heart acquired in a large population of healthy volunteers. Methods We studied a group 119 healthy volunteers (60 male, 59 female) which consisted of three age groups of nearly equal size (I: 20-34 yrs.,II: 35-49 yrs.,III: ≥50 yrs.). CMR images were acquired on a 1.5 T whole body MRI applying a standard cine SSFP sequence. Right atrial (RA) function and morphology as well as RV sizes were assessed in a 4-chamber view. For the measurement of the RV volumes and function short axis views were used. End-diastolic and end-systolic volumes and diameters (EDV, ESV, EDD, ESD), RV stroke volume and ejection fraction (SV, EF) were measured. As the emptying of the RA is a combination of active and passive mechanisms we tried to quantify the contribution of the contraction by measuring the RA contractive stroke volume (RA CSV) and ejection fraction (RA CEF). Furthermore the RV end-diastolic and end-systolic length (EDL, ESL) and the RA end-diastolic and endsystolic area (EDA, ESA) were quantified. Body surface area (BSA) was calculated using the Mosteller formula. A p-value <0.05 was regarded as statistically significant. Results

Feature tracking in cardiac magnetic resonance imaging to evaluate normal myocardial function

Background Assessment of left ventricular function (LV) is one of the most important tasks of clinical cardiac magnetic resonance imaging (CMR). Regional and global LV function has been recognized to differentiate various myocardial disorders. The aim of the study was to provide normal values for myocardial deformation parameters derived from the feature tracking imaging (FTI) algorithm applied to standard CMR cine SSFP sequences in a large group of healthy subjects. The feature tracking algorithm (2D CPA MR©, TomTec Imaging Systems GmbH), is a two dimensional deformation analysis of the myocardium that was originally designed for echocardiographic image analysis, which has now been transferred to CMR SSFP sequences without the need for additional scans. This novel approach may have potential advantages over existing methods, such as broad availability, vendor independency and lack of timeconsuming post processing.

Artifact suppression of SSFP cine sequences at 3T using a novel automatic 3D shimming algorithm

Methods A total of 20 consecutive patients scheduled to undergo a clinically indicated CMR in normal sinus rhythm and able to perform apnea were prospectively enrolled to be scanned in a 3T system (MAGNETOM Verio, Siemens, Germany). Frequency scout images were acquired in two and four chamber views and the frequency offset associated with least banding artifacts involving the heart was manually set (Figure 1) for the acquisition of short and long axis segmented cine SSFP images covering the entire ventricular volumes (bandwidth of 700-750 Hz/ pixel and echo spacing of 3.4 ms). The same sequences were then repeated with the offset reset to 0 Hz (only change made) but with the use of a novel 3D shimming algorithm restricted to the heart (instead of the entire FOV) based on a patient specific GRE fieldmap previously generated (WIP Siemens, Germany). Images were blindly evaluated for segmental function (normal vs. abnormal), and the presence of artifacts within the heart (none, minor or important the latter meaning that at least one myocardial segment could not be assessed). Ventricular volumes were also blindly mea-

Feasibility of High-Dose Dobutamine Stress SSFP Cine MRI at 3 Tesla with Patient Adaptive Local RF Shimming using Dual-Source RF Transmission: Initial Results

To investigate the feasibility of high-dose dobutamine stress (HDDS) imaging using SSFP sequences at 3 T employing patient-adaptive local RF-shimming using a dual-source RF transmission system. 13 Patients underwent a HDDS protocol on a 3 T MRI scanner (Achieva 3.0T-TX, Philips Healthcare), equipped with a dual-source RF transmission system. SSFP cine sequences using patient-adaptive local RF-shimming (RF-S) were compared to cine images acquired without additional shimming. Image quality was evaluated on a 4-point grading scale and number of non-diagnostic segments assessed. Contrast (CN) between myocardium (SIM) and blood pool (SIB) was calculated [(SIB-SIM)/(SIB+SIM)]. Image quality both at rest and maximum stress was significantly improved with RF-S (ED:3.56±0.5 vs. 3.23±0.63; ES:3.4±0.5 vs. 3.1±0.7) compared to no RF-S (ED:2.9±0.72 vs. 2.15±0.78; ES:2.64±0.74 vs. 1.95±0.76; p<0.01). The amount of non-diagnostic segments was significantly reduced when using RF-S at rest and stress (3 vs. 39; 19 vs. 78, p<0.05). All HDDS studies were diagnostic if performed with RF-S (n=13/13) in comparison to conventional shimming (n=5/13). Image contrast was improved for SSFP sequences with RF-S (0.53±0.08) compared to conventional images (0.46±0.09, p=0.06). Patient-adaptive local RF-shimming using a dual-source RF transmission system allows for reliable SSFP imaging in a clinical high-dose dobutamine stress protocol at 3 T. RF-S significantly improves image quality and reduces the number of non-diagnostic myocardial segments.

Measurement of pulmonary arterial pulse wave reflection from single-slice phase-contrast and steady-state free precession MRI

Summary Pulmonary arterial hypertension (PAH) is associated with elevated pulmonary vascular resistance, resulting in increased reflection of pressure and flow waves from distal vessels 1 . The gold standard for assessing PAH is right heart catheterization, an invasive procedure that carries a 5% risk of major complications 2 .W e validate a Methods The right pulmonary artery in three healthy adult volun- teers was imaged on a 1.5 T MR system (Siemens, Ger- many) using retrospectively ECG-gated cine PC and SSFP sequences to quantify blood velocity and vessel cross-section, respectively. PC and SSFP images were co-registered in MATLAB (The MathWorks, USA). The arterial lumen was outlined semi-automatically using Segment (Medviso, Sweden), yielding flow and area time series that were resolved into forward and backward flow waves in MATLAB. The frequency-domain ratios of backward to forward flow waves yielded estimates of R which were then averaged over the fundamental heart frequency and the next two harmonics 3 and compared to literature values using a two-tailed Student's t-test.

Imaging contrast agent concentration and extracellular volume fraction in the right ventricle

Background Globally increased myocardial extracellular volume fraction (ECVF) has been associated with diffuse myocardial fibrosis. ECVF can be estimated using blood and tissue concentrations of gadolinium contrast agent, [Gd], which are calculated using baseline and post-contrast T1 values [1]. To date, T1 quantification has been limited to the left ventricle (LV) with moderate spatial resolution (~2 mm) and long imaging windows (>200 ms) to accommodate breath-hold acquisitions. These methods have insufficient spatial resolution to image the relatively thin-walled right ventricle (RV). A new cine-imaging approach for the measurement of contrast agent concentration and ECVF using saturation-recovery preparation is evaluated in the LV and RV. Methods A saturation-recovery gated-segmented cine SSFP sequence, similar to the multi-contrast late enhancement imaging method [2], provides a short acquisition window (< 50 ms) enabling end-systolic imaging and higher spatial resolution (~1 mm). Bloch equation simulations of the sequence were used to generate a look-up table to relate the measured ratio of post- to pre-contrast image intensity to the tissue concentration of contrast agent (CLAIR - Contrast Level Assessment using Intensity Ratios). Short axis images were acquired in 9 subjects from an ongoing study of heart failure (Alberta HEART), with contrast-enhanced images at 15 min post 0.15mmol/kg Gadovist. Typical CLAIR pulse sequence parameters: FOV=300mm, 256 matrix, 8 mm slice, flip angle=73°, TE=1.66ms, TR=3.32ms, VPS=14, TI=300ms. Average LV [Gd] in subjects was compared to values obtained using a saturation-recovery SSFP T1-mapping sequence [3] calculated using [Gd] = ΔR1/r (ΔR1 =

MRI morphological and functional method for clear distinction of patients with left ventricular non-compaction, inflammatory dilated cardiomyopathy and physiological myocardial trabeculation

Background Left ventricular non-compaction (LVNC) cardiomyopathy is characterized by a thin, compacted epimyocardial and a thick non-compacted, trabeculated endomyocardial layer. High-resolution cardiac magnetic resonance imaging (CMR) has been clinically successfully used to establish a Non-compact-to-compact- (NCTC) ratio of 2.3 in a 4-chamber view which is regarded pathological. Clinically, in patients with dilated cardiomyopathy (DCMP) and noticeably even in volunteers with physiological myocardial trabecularisation, up to 28% of verifiably healthy participants demonstrated the NCTC-ratio ≥ 2.3 so that there is a clinical need for a better distinction between patients with LVNC, DCMP and healthy subjects. We hypothesized that MRI is able to clearly distinguish LVNC from DCMP and healthy volunteers by a novel combined MRI and statistical approach of morphological and functional parameters. Methods 31 LVNC patients, defined by an MRI NCTC-ratio >2.3 (in a 4-chamber view plus one additional parameter (fulfilment of echo-criteria, histology, genetic proof, invasive X-ray), 13 patients with histologically proven inflammatory DCMP as well as 117 male/female healthy volunteers were studied employing a vector-ECG gated multislice 2-, 3-, 4-chamber and short axis (SA) standard cine SSFP-sequence covering the entire left ventricle. Functional parameters like end-diastolic, end-systolic volumes and ejection fraction were generated via SA SSFP slices as usual. Compacted and non-compacted

Cardiac MRI: evaluation of phonocardiogram-gated cine imaging for the assessment of global und regional left ventricular function in clinical routine

To validate a phonocardiogram (PCG)-gated cine imaging approach for the assessment of left ventricular (LV) function. In this prospective study, cine MR imaging of the LV was performed twice in 79 patients by using retrospectively PCG- and retrospectively ECG-gated cine SSFP sequences at 1.5 T. End-diastolic volumes (EDV), end-systolic volumes (ESV), stroke volumes (SV), ejection fraction (EF), muscle mass (MM), as well as regional wall motion were assessed. Subgroup analyses were performed for patients with valvular defects and for patients with dysrhythmia. PCG-gated imaging was feasible in 75 (95%) patients, ECG-gating in all patients. Excellent correlations were observed for all volumetric parameters (r > 0.98 for all variables analysed). No significant differences were observed for EDV (-0.24 ± 3.14 mL, P = 0.5133), ESV (-0.04 ± 2.36 mL, P = 0.8951), SV (-0.20 ± 3.41 mL, P = 0.6083), EF (-0.16 ± 1.98%, P = 0.4910), or MM (0.31 ± 4.2 g, P = 0.7067) for the entire study cohort, nor for either of the subgroups. PCG- and ECG-gated cine imaging revealed similar results for regional wall motion analyses (115 vs. 119 segments with wall motion abnormalities, P = 0.3652). The present study demonstrates that PCG-gated cine imaging enables accurate assessment of global and regional LV function in the vast majority of patients in clinical routine. Phonocardiogram-gating is an alternative to electrocardiographic-gating in cardiac MR. Phonocardiogram-gated imaging allows reliable assessment of global and regional left-ventricular function. Phonocardiogram-gating is feasible in patients with valvular lesions or cardiac dysrhythmia. Because phonocardiogram-gating is insensitive to magneto-hydrodynamic effects, it is suitable for ultra-high field.

Maladaptive hypertrophy after acute myocardial infarction positive effect of bone marrow-derived stem cell therapy on regional remodeling measured by cardiac MRI

In the aftermath of myocardial infarction, increased loading conditions will trigger hypertrophy of viable myocardium. This in turn causes deterioration of regional contractility. Cardiac magnetic resonance imaging (cMRI) allows the exact differentiation of viable and infarcted myocardium and therefore the measurement of regional wall thickness and function. Bone marrow-derived stem cell (BMC) transfer has been shown to improve global function and remodeling. The present study examines the effect of BMC transfer on regional remodeling and function after myocardial infarction by cMRI. Fifty-four patients of the MR substudy of the REPAIR-AMI trial have been studied at baseline and 12-month follow-up. Enddiastolic wall thickness (EDWT) and wall thickening (WT%) have been measured on SSFP cine sequences. Enddiastolic wall thickness decreased in both placebo and BMC groups in viable as well as infarcted segments. The effect was largest in the pre-specified subgroup of patients below the median EF of 48.9% (infarcted segments -1.14 mm Placebo vs. -1.91 mm BMC, p for interaction 0.01, remote segments -0.19 mm Placebo vs. -0.94 mm BMC, p for interaction 0.00001). Corrected for baseline values BMC therapy yielded smaller EDWT at 12 months in infarcted and remote segments (infarcted 7.58 mm Placebo vs. 6.13 mm BMC p = 0.0001, remote 8.76 mm Placebo vs. 7.32 mm BMC, p = 0.0001). This was associated with better contractility within the infarcted segments among BMC patients (WT% 24.17% Placebo vs. 49.31% BMC, p = 0.0001). The WT% was inversely correlated with EDWT (r = -0.37, p = 0.0001). Bone marrow-derived stem cell therapy yields smaller EDWT when compared with placebo patients suggesting a positive effect on maladaptive hypertrophy of viable myocardium. This notion is supported by the enhanced regional contractility within the BMC group which is inversely correlated with EDWT.

Feasibility of high-dose dobutamine stress SSFP cine MRI at 3 Tesla with patient adaptive local RF shimming using dual-source RF transmission: initial results

Cine SSFP sequences have become the gold standard for assessment of myocardial function at 1.5T. However, cine imaging at higher-field strengths is hampered by SAR limitations, the increased inhomogeneity of the B1 (RF) and B0 field and the high sensitivity of SSFP sequences to off-resonance artefacts. The effect is even more pronounced in HDDS studies, which are associated with a significant increase in heart rate and consequently more complex and faster blood flow. Previously, spoiled gradient-echo sequences have been proposed as an alternative for stress studies at 3T. Recently, the introduction of a dual-source RF transmission system with patient-adaptive local RF-shimming has lead to a significant improvement of image quality of SSFP imaging at 3T during resting conditions and may thus allow for reliable imaging of cardiac function even at high heart rates.

MRI for detection of anomalous pulmonary venous drainage in patients with sinus venosus atrial septal defects

Purpose of this survey was to estimate the value of MRI for the assessment of the anatomical and functional features of sinus venosus atrial septal defect (SVD). This prospective study included 13 surgically proven cases of SVD out of 81 subjects submitted to MRI due to inconclusive transthoracic echocardiography (TTE) or suspicion of high intracardiac and/or extracardiac shunt volumes based on echocardiographic findings. MRI examination included cine SSFP sequences, contrast-enhanced 3D gradient-echo (GE) sequences for MR angiography (MRA) and phase-contrast flow-measurements. MRI revealed nine patients with a superior and four with an inferior SVD. Anomalous pulmonary venous drainage (APVD) was observed only in subjects with a superior SVD, and it was right-sided in all cases. All MRI and MRA results for the SVD patients were confirmed intraoperatively. The Correlation coefficient between MR flow measurements and cardiac catheterisation was 0.94 (P<0.0001). According to MRI the rest of the subjects (n=68) presented a secundum ASD, whereas in 18% an APVD coexisted. The latter MR outcomes concurred with the cardiac catheterisation (n=56) and operative (n=12) results. MRI provides a reliable, non-invasive method for evaluation of SVDs, APVDs and shunt quantification.

New insight of CMR in the diagnosis of left ventricular non-compaction: measurement of trabeculated left ventricular mass

Methods Between January 2003 and 2008, we prospectively included 16 patients with LVNC. During the mean period we included 16 patients with dilated cardiomyopathy (DCM), 16 patients with hypertrophic cardiomyopathy (HCM), and 16 control subjects. All patients underwent a 1.5 T CMR with SSFP cine sequences, the following parameters were used: TR/TE = 40 ms/1.8 ms, slice thickness = 6 mm, no gap between slice, flip angle = 65°, matrix = 148 × 256, field of view = 350 × 350 mm, temporal resolution = 35 ms, retrospective gating for the Siemens scan; and TR/TE = 3.5/1.5 ms, slice thickness = 6 mm, no gap between slice, flip angle = 60°, matrix = 148 × 256, field of view = 350 × 350 mm, temporal resolution = 35 ms, retrospective gating for the Philips scan. LV volumes, LV ejection fraction and trabeculated LV mass were measured (Figure 1). Figure 1: Illustration of the described method for measuring the global and trabeculated LV masses in patients with LVNC, DCM, HCM and controls. Row A shows the short axis end-diastolic cine images used for measurement without contouring. Row B shows inclusion of papillary muscles but exclusion of LV trabeculation for the measurements of the compacted LV mass. Row C shows inclusion of papillary muscles and trabeculation for the measurements of global LV mass.