Pulmonary Vein Stenosis as a Pitfall of Ventilation/Perfusion SPECT/CT for Pulmonary Embolism.

ABSTRACT: A 58-year-old man with progressive dyspnea and recurrent extensive left-sided pleural effusion underwent pulmonary ventilation/perfusion SPECT/CT, which showed a pronounced mismatched perfusion deficit of the entire, normally ventilated left lung. As unilateral perfusion deficits of an entire lobe are generally not due to pulmonary embolism, further CT angiography and cardiac MRI were conducted. These examinations revealed high-grade left pulmonary vein stenosis (PVS) caused by pulmonary vein isolation performed for atrial fibrillation 3 and 4 years earlier. Thus, in addition to, for example, neoplastic processes or pulmonary congenital vascular abnormalities, PVS must be considered as a differential diagnosis and possible pitfall in ventilation/perfusion SPECT/CT in dyspneic patients with prior pulmonary vein isolation.

Antibody-mediated rejection with detection of de novo donor-specific anti-human leucocyte antigen Class II antibodies 3 years after heart transplantation: a case report.

BACKGROUND: Antibody-mediated rejection (AMR) in cardiac transplantation may manifest early within the first weeks after transplantation but also late after months to years following transplantation resulting in mild heart failure to cardiogenic shock. While patients with early cardiac AMR are less affected and seem to have survival rates comparable to transplant recipients without AMR, late cardiac AMR is frequently associated with graft dysfunction, fulminant forms of cardiac allograft vasculopathy, and a high mortality rate. Nevertheless, AMR of cardiac allografts remains difficult to diagnose and to treat. CASE SUMMARY: We report the case of a 47-year-old male patient with late AMR of the cardiac allograft 3 years after heart transplantation. Antibody-mediated rejection was confirmed by endomyocardial biopsy and the presence of donor-specific antibodies (DSA). The patient was treated with high dose of prednisolone, plasmapheresis, intravenous Gamma Globulin, rituximab, immunoadsorption, and bortezomib. Under this treatment regimen left ventricular ejection fraction and pro B-type natriuretic peptide recovered, and the patient improved to New York Heart Association Class I. Currently, 3 years after the diagnosis of cardiac AMR, graft function continues to be nearly normal, and there is no evidence for transplant vasculopathy. DISCUSSION: This case illustrates that AMR can occur at any time after transplantation. Although graft function fully recovered after treatment in our patient, the level of DSA remained high, suggesting that DSA may not be a reliable parameter to determine the intensity and duration of the therapy.

Segmental biventricular analysis of myocardial function using high temporal and spatial resolution tissue phase mapping.

OBJECTIVE: Myocardial dysfunction of the right ventricle (RV) is an important indicator of RV diseases, e.g. RV infarction or pulmonary hypertension. Tissue phase mapping (TPM) has been widely used to determine function of the left ventricle (LV) by analyzing myocardial velocities. The analysis of RV motion is more complicated due to the different geometry and smaller wall thickness. The aim of this work was to adapt and optimize TPM to the demands of the RV. MATERIALS AND METHODS: TPM measurements were acquired in 25 healthy volunteers using a velocity-encoded phase-contrast sequence and kt-accelerated parallel imaging in combination with optimized navigator strategy and blood saturation. Post processing was extended by a 10-segment RV model and a detailed biventricular analysis of myocardial velocities was performed. RESULTS: High spatio-temporal resolution (1.0 × 1.0 × 6 mm3, 21.3 ms) and the optimized blood saturation enabled good delineation of the RV and its velocities. Global and segmental velocities, as well as time to peak velocities showed significant differences between the LV and RV. Furthermore, complex timing of the RV could be demonstrated by segmental time to peak analysis. CONCLUSION: High spatio-temporal resolution TPM enables a detailed biventricular analysis of myocardial motion and might provide a reliable tool for description and detection of diseases affecting left and right ventricular function.

Altered Regional Myocardial Mechanics in Transplanted Hearts: Influence of Time and Transplantation.

Background Global longitudinal strain is reduced in heart transplant recipients, but little is known about regional contractility of the transplanted heart. Moreover, it is unclear if factors such as time after transplant and ischemic time have an influence on regional contractility. To test for regional changes in myocardial deformation, we assessed regional myocardial deformation using three-dimensional speckle tracking echocardiography in heart transplant recipients and controls. Methods Global and regional longitudinal, circumferential, and radial strain was assessed in 51 heart transplant recipients and a control group of healthy individuals (n = 26). Moreover, we correlated regional contractility with clinical characteristics and compared subgroups of heart transplant recipients with normal (n = 32) and reduced left ventricular ejection fraction (n = 32). Results Global longitudinal and circumferential strain was significantly reduced in all heart transplant recipients, as well as in the transplant group with normal ejection fraction compared with the control group (p < 0.001). Global radial strain (GRS) was elevated in both transplant groups, but was significantly higher in transplant recipients with normal ejection fraction compared with the control group (p < 0.01). Both transplant groups revealed lower longitudinal and circumferential strain values in the mid- and apical regions (p < 0.001), whereas longitudinal and circumferential strain was higher in the basal region (p < 0.01). In both groups, transplanted hearts showed increased radial strain in the basal (p < 0.05, p < 0.01) and midregions (p = 0.22; p < 0.01) and did not differ in the apical regions. Cold ischemic time (150 ± 12.6 minutes) was independently associated with reduction in circumferential strain. Time since transplantation ranging from 18 days to 21 years had no effect on myocardial deformation parameters. Conclusion Left ventricular mechanics in transplanted hearts display significantly different systolic deformation patterns than native hearts. Strain capability forms a regional gradient from the base toward the apex. The presence of a time-independent deformation pattern and the correlation with cold ischemic time suggest damage induced by the transplantation itself. These findings might be important for understanding pseudo-abnormal echocardiograms in heart transplant patients.

Cold ischaemic time and time after transplantation alter segmental myocardial velocities after heart transplantation.

OBJECTIVES: The aim of this study was to investigate changes in segmental, three-directional left ventricular (LV) velocities in patients after heart transplantation (Tx). METHODS: Magnetic resonance tissue phase mapping was used to assess myocardial velocities in patients after Tx (n = 27) with normal LV ejection fraction (63 ± 5%) and those without signs of rejection. Regional wall motion and dyssynchrony were analysed in relation to cold ischaemic time (150 ± 57 min, median = 154 min), age of the donor heart (35 ± 13 years, median = 29 years), time after transplantation (32 ± 26 months, median = 31 months) and global LV morphology and function. RESULTS: Segmental myocardial velocities were significantly altered in patients with cold ischaemic times >155 min resulting in an increase in peak systolic radial velocities (2 of 16 segments, P = 0.03-0.04) and reduced segmental diastolic long-axis velocities (5 of 16 segments, P = 0.01-0.04). Time after transplantation (n = 8 patients <12 months after Tx vs n = 19 >12 months) had a significant influence on systolic radial velocities (increased in 2 of 16 segments, P = 0.01-0.04) and diastolic long-axis velocities (reduced in 5 of 16 segments, P = 0.02-0.04). Correlation analysis and multiple regression revealed significant relationships of cold ischaemic time (R = -0.384, P = 0.048), the donor heart's age (ß= 0.9, P = 0.01) and time from transplantation (ß= -0.36, P = 0.03) with long-axis diastolic dyssynchrony. CONCLUSIONS: Time after transplantation and cold ischaemic time strongly affect segmental systolic and diastolic motion in patients after Tx. The understanding of alterations in regional LV motion in the transplanted heart under stable conditions is essential in order to utilize this methodology in the future as a potentially non-invasive means of diagnosing transplant rejection.

K-t GRAPPA accelerated phase contrast MRI: Improved assessment of blood flow and 3-directional myocardial motion during breath-hold.

PURPOSE: To evaluate spatiotemporal parallel imaging with R = 5 in comparison to conventional parallel imaging with R = 2 applied to phase contrast (PC) magnetic resonance imaging (MRI). This was motivated by the fact that scan times for PC imaging often exceed breath-hold capabilities of patients even with standard parallel imaging using typical reduction factors of R = 2. MATERIALS AND METHODS: K-t generalized autocalibrating partially parallel acquisition (GRAPPA) acquisition was validated in phantom measurements and then applied in 10 volunteer and three patient examinations. Due to the higher reduction factor compared to conventional GRAPPA, k-t GRAPPA measurements could be performed during breath-hold with high spatial and temporal resolution. K-t GRAPPA scans were compared to GRAPPA acquired during free-breathing with navigator respiration control. In addition, spatiotemporally accelerated PC imaging was acquired during free-breathing for comparison of k-t-accelerated breath-held scans. RESULTS: Substantial improvements in image quality for the breath-hold measurements were observed. Significantly reduced peak velocities were found for the GRAPPA protocol compared to the k-t-accelerated breath-hold scans for both flow (8%) and myocardial motion (up to 30%) measurements. CONCLUSION: Spatiotemporal acceleration allows the performance of high temporal or spatial resolution PC imaging during breath-hold while providing high image quality and robust acquisition of functional information that cannot be achieved during breath-hold with standard techniques.

Spatial correlation of action potential duration and diastolic dysfunction in transgenic and drug-induced LQT2 rabbits.

BACKGROUND: Enhanced dispersion of action potential duration (APD) is a major contributor to long QT syndrome (LQTS)-related arrhythmias. OBJECTIVE: To investigate spatial correlations of regional heterogeneities in cardiac repolarization and mechanical function in LQTS. METHODS: Female transgenic LQTS type 2 (LQT2; n = 11) and wild-type littermate control (LMC) rabbits (n = 9 without E4031 and n = 10 with E4031) were subjected to phase contrast magnetic resonance imaging to assess regional myocardial velocities. In the same rabbits' hearts, monophasic APDs were assessed in corresponding segments. RESULTS: In LQT2 and E4031-treated rabbits, APD was longer in all left ventricular segments (P < .01) and APD dispersion was greater than that in LMC rabbits (P < .01). In diastole, peak radial velocities (Vr) were reduced in LQT2 and E4031-treated compared to LMC rabbits in LV base and mid (LQT2: -3.36 ± 0.4 cm/s, P < .01; E4031-treated: -3.24 ± 0.6 cm/s, P < .0001; LMC: -4.42 ± 0.5 cm/s), indicating an impaired diastolic function. Regionally heterogeneous diastolic Vr correlated with APD (LQT2: correlation coefficient [CC] 0.38, P = .01; E4031-treated: CC 0.42, P < .05). Time-to-diastolic peak Vr were prolonged in LQT2 rabbits (LQT2: 196.8 ± 2.9 ms, P < .001; E4031-treated: 199.5 ± 2.2 ms, P < .0001, LMC 183.1 ± 1.5), indicating a prolonged contraction duration. Moreover, in transgenic LQT2 rabbits, diastolic time-to-diastolic peak Vr correlated with APD (CC 0.47, P = .001). In systole, peak Vr were reduced in LQT2 and E4031-treated rabbits (P < .01) but longitudinal velocities or ejection fraction did not differ. Finally, random forest machine learning algorithms enabled a differentiation between LQT2, E4031-treated, and LMC rabbits solely based on "mechanical" magnetic resonance imaging data. CONCLUSIONS: The prolongation of APD led to impaired diastolic and systolic function in transgenic and drug-induced LQT2 rabbits. APD correlated with regional diastolic dysfunction, indicating that LQTS is not purely an electrical but an electromechanical disorder.

Aging does not affect radial viscoelastic behavior of the left ventricle.

OBJECTIVES: This study investigates the effect of aging on the radial viscoelastic behavior of the left ventricle (LV) based on a previously validated model that uses myocardial tissue phase mapping (TPM) of cine phase-contrast MRI. METHODS: Previous studies suggest that aging remarkably influences regional myocardial motion, mostly myocardial velocities in both radial and long-axis directions. However, the effect of aging on cardiac viscoelasticity, which exhibits time-dependent strain, has not been elucidated yet. In this study, myocardial velocity and displacement mapping of the LV was performed using TPM in 39 healthy subjects divided into three age groups. The viscoelasticity parameters were obtained for each segment of the LV and compared among the studied groups. RESULTS: The analyses showed that myocardial elasticity ranged from approximately 20 to -20 dyne/cm2 during a cardiac cycle, and the myocardial viscous-damping component ranged from -1 to 1 dyne × s/cm2. Overall, no statistically significant difference was observed in the viscoelasticity components among the subjects in the different age groups (p > 0.05). CONCLUSION: Myocardial viscoelastic behavior of the LV in radial direction was found to be considerably similar in pattern and magnitude among the studied subjects of different age groups with no statistically significant difference, despite the fact that the regional myocardial velocities change due to aging.

Age, gender, blood pressure, and ventricular geometry influence normal 3D blood flow characteristics in the left heart.

AIMS: The aim of this study was to assess the effect of age, gender, physiological, and global cardiac function parameters on differences in normal 3D blood flow in the left ventricle (LV) and atrium (LA) using 4D flow magnetic resonance imaging (MRI). METHODS AND RESULTS: Four-dimensional flow MRI was acquired in healthy volunteers of two age and gender groups: <30 years (6 women, n = 12) and >50 years (6 women, n = 12). Systolic and early to mid-diastolic vortex flow (number of vortices, duration, area, peak velocity inside the vortex) in the LA and LV was assessed using intra-cardiac flow visualization based on 3D particle traces and velocity vector fields. A larger number of vortices in the LA were found in young compared with older individuals (number of diastolic vortices: 1.6 ± 0.8 vs. 0.7 ± 0.7, P = 0.01) with higher velocities (54 ± 12 cm/s vs. 41 ± 11 cm/s in systole, 47 ± 13 vs. 31 ± 8 cm/s in diastole, P < 0.05). Vortices in the LV base were smaller in women compared with men (369 ± 133 vs. 543 ± 176 mm(2), P = 0.009), while vortex size was increased in mid-ventricular locations (maximum area: 546 ± 321 vs. 293 ± 174 mm(2), P < 0.05). Correlation analysis revealed significant relationships (P = 0.005-0.048, correlation coefficients = 0.44-0.84) between LA and LV vortex characteristics (number, size, vortex velocities) and blood pressure as well as end-diastolic volume, LV length, and ejection fraction. CONCLUSIONS: Flow patterns in the left heart demonstrated differences related to age, gender, blood pressure, and ventricular geometry. The findings constitute a prerequisite for the understanding of the impact of cardiac disease on intra-cardiac haemodynamics.

Diagnosis of viral myocarditis by cardiac magnetic resonance and viral genome detection in peripheral blood.

In patients with acute myocarditis, viral genome can be detected in plasma and peripheral leukocytes. Its relationship with active myocardial inflammation, however, is not well understood. Myocardial edema as a feature of inflammation and myocardial necrosis or fibrosis can be frequently observed in patients with acute myocarditis by cardiovascular magnetic resonance (CMR). We assessed the association of viral genome presence in peripheral blood samples with myocardial edema and irreversible injury. We examined consecutive patients with clinically suspected myocarditis after an episode of viral illness. State-of-the-art methods were used for detecting myocardial edema and irreversible injury using CMR and viral genome applying reverse transcribed, nested polymerase chain reaction in peripheral blood samples. The specificity of viral amplification products was confirmed by automatic DNA sequencing. Of a total of 55 patients (53.5 ± 15.6 years), 21 were positive for viral genome in peripheral leukocytes. Interestingly, 18 (86%) of these patients also showed global myocardial edema, as compared to only 7/34 (21%) without PCR evidence for viral genome. The overall agreement between CMR criteria for edema and viral PCR was 84%. In contrast, there was no significant relationship of viral genome presence with myocardial necrosis or scars. In patients with clinically suspected myocarditis, myocardial edema but not irreversible myocardial injury is associated with the presence of viral genome in peripheral blood.

A quantitative comparison of regional myocardial motion in mice, rabbits and humans using in-vivo phase contrast CMR.

BACKGROUND: Genetically manipulated animals like mice or rabbits play an important role in the exploration of human cardiovascular diseases. It is therefore important to identify animal models that closely mimic physiological and pathological human cardiac function. METHODS: In-vivo phase contrast cardiovascular magnetic resonance (CMR) was used to measure regional three-directional left ventricular myocardial motion with high temporal resolution in mice (N=18), rabbits (N=8), and humans (N=20). Radial, long-axis, and rotational myocardial velocities were acquired in left ventricular basal, mid-ventricular, and apical short-axis locations. RESULTS: Regional analysis revealed different patterns of motion: 1) In humans and rabbits, the apex showed slower radial velocities compared to the base. 2) Significant differences within species were seen in the pattern of long-axis motion. Long-axis velocities during systole were fairly homogeneously distributed in mice, whereas humans showed a dominant component in the lateral wall and rabbits in the base. 3) Rotational velocities and twist showed the most distinct patterns in both temporal evolution and relative contribution of base, mid-ventricle and apex, respectively. Interestingly, a marked difference in rotational behavior during early-systole was found in mice, which exhibited clockwise rotation in all slice locations compared to counter-clockwise rotation in rabbits and humans. CONCLUSIONS: Phase contrast CMR revealed subtle, but significantly different regional myocardial motion patterns in mice, rabbits and humans. This finding has to be considered when investigating myocardial motion pattern in small animal models of heart disease.

Evidence of myocardial edema in patients with nonischemic dilated cardiomyopathy.

BACKGROUND: Nonischemic dilated cardiomyopathy (DCM) is associated with high mortality and morbidity. Cardiovascular magnetic resonance allows for the noninvasive assessment of function, morphology, and myocardial edema. Activation of inflammatory pathways may play an important role in the etiology of chronic DCM and may also be involved in the disease progression. HYPOTHESIS: The purpose of our study was to assess the incidence of myocardial edema as a marker for myocardial inflammation in patients with nonischemic DCM. METHODS: We examined 31 consecutive patients ( mean age, 57 ± 12 years) with idiopathic DCM. Results were compared with 39 controls matched for gender and age (mean age, 53 ± 13 years). Parameters of left ventricular function and volumes, and electrocardiogram-triggered, T2-weighted, fast spin echo triple inversion recovery sequences were applied in all patients and controls. Variables between patients and controls were compared using t tests for quantitative and χ2 tests for categorical variables. RESULTS: Ejection fraction (EF) was 40.3 ± 7.8% in patients and 62.6 ± 5.0% in controls (P < 0.0001). In T2-weighted images, patients with DCM had a significantly higher normalized global signal intensity ratio compared to controls (2.2 ± 0.6 and 1.8 ± 0.3, respectively, P = 0.0006), consistent with global myocardial edema. There was a significant but moderate negative correlation between signal intensity ratio in T2-weighted images and EF (-0.39, P < 0.001). CONCLUSIONS: Evidence shows that myocardial edema is associated with idiopathic nonischemic DCM. Further studies are needed to assess the clinical and prognostic impact of these findings.

Three-directional acceleration phase mapping of myocardial function.

An optimized acceleration encoded phase contrast method termed "acceleration phase mapping" for the assessment of regional myocardial function is presented. Based on an efficient gradient waveform design using two-sided encoding for in vivo three-directional acceleration mapping, echo and repetition times TE = 12-14 ms and TR = 15-17 ms for low accelerations sensitivity aenc = 5-8 m/s(2) were achieved. In addition to phantom validation, the technique was applied in a study with 10 healthy volunteers at 1.5T and 3T to evaluate its feasibility to assess regional myocardial acceleration at 1.5T and 3T. Results of the acceleration measurements were compared with the temporal derivative of myocardial velocities from three-directional velocity encoded standard phase contrast MRI in the same volunteers. The feasibility to assess myocardial acceleration along the radial, circumferential, and longitudinal direction of the left ventricle was demonstrated. Despite improved signal-to-noise-ratio at 3T (34% increase compared with 1.5T), image quality with respect to susceptibility artifacts was better 1.5T compared with 3T. Analysis of global and regional left ventricular acceleration showed characteristic patterns of systolic and diastolic acceleration and deceleration. Comparisons of directly measured and derived myocardial acceleration dynamics over the cardiac cycle revealed good correlation (r = 0.45-0.68, P < 0.01) between both methods.

Time-resolved three-dimensional magnetic resonance velocity mapping of cardiovascular flow paths in volunteers and patients with Fontan circulation.

OBJECTIVE: To apply flow-sensitive magnetic resonance imaging for the evaluation of whole-heart flow characteristics in healthy volunteers and patients with Fontan circulation. METHODS: Time-resolved three-dimensional magnetic resonance velocity mapping (spatial resolution = 2.5 × 2.8 × 2.8mm(3), temporal resolution = 38.4 ms) was acquired in normal controls and in four Fontan patients with extracardiac total cavopulmonary connection. Data analysis included flow connectivity mapping and flow quantification of arterial and venous blood flow. Haemodynamics in four patients with Fontan circulation were individually evaluated in the aorta, caval veins and left and right pulmonary arteries. RESULTS: In four controls, nine distinct flow features were consistently identified with good feature clarity (median = 2 in 80.6% of readings) and image quality (median = 2 in 75.0% of readings). In patients, a marked variability of flow from the caval veins towards the left and right pulmonary arteries (flow ratio = 1.7 ± 0.6, range 1.2-2.6 vs 1.1 ± 0.1 in controls) was found. Increased offset of the caval venous connection resulted in enhanced pulmonary flow asymmetry. Compared with controls, reduced pulsatility in pulmonary arteries (1.4 ± 0.6 vs 4.1 ± 0.6 in controls) and caval veins (1.2 ± 0.4 vs 2.8 ± 1.1 in controls) were observed. Peak flow was reduced in both superior (22 ± 14 mls(-1) vs 76 ± 7 mls(-1) in controls) and inferior vena cava (61 ± 28 mls(-1) vs 187 ± 42 mls(-1) in controls). CONCLUSIONS: This feasibility study demonstrated the potential of whole-heart three-dimensional magnetic resonance velocity mapping to reveal overt haemodynamic differences in surgically palliated congenital heart with similar extracardiac cavopulmonary connection geometry. Future studies are warranted to evaluate its diagnostic impact for improved evaluation of the pre- and postoperative status in the individual patient.

[Constrictive pericarditis: etiology, diagnostic work-up, and therapy]. / Pericarditis constrictiva: Atiologie, Diagnostik und Therapie.

Constrictive pericarditis is characterized by a fibrous thickened pericardial layer which prevents the cardiac chambers from regular filling. Today, this disease is often caused by previous cardiac surgery or mediastinal radiotherapy, whereas tuberculosis as a cause is less important nowadays. Due to the reduced diastolic filling the cardiac output is diminished and the veins are engorged. The patients present with ascites, liver congestion, and dilated jugular veins. A pericardial effusion, the ECG or an echocardiography may give first hints for the diagnosis. The chest X-ray examination might detect pericardial calcifications (see Figure 2). Doppler echocardiography and cardiac catheterization, especially during breathing maneuvers, are diagnostic, as they demonstrate the diastolic filling disturbance ("dip-plateau sign", see Figure 1), the equal increase of left and right ventricular end-diastolic and mean atrial pressures, and the strong dependency of ventricular filling from respiration. Computed tomography or magnetic resonance imaging might reveal the thickened pericardial layer (see Figures 3 and 4). The most important differential diagnosis is restrictive cardiomyopathy, which has similar clinical and hemodynamic findings. A comprehensive diagnostic work-up is necessary, as the constrictive pericarditis may be cured by a timely performed pericardial resection.

Magnetic resonance tissue phase mapping of myocardial motion: new insight in age and gender.

BACKGROUND: An exact understanding of normal age- and gender-matched regional myocardial performance is an essential prerequisite for the diagnosis of heart disease. Magnetic resonance phase-contrast imaging (tissue phase mapping) enabling the analysis of segmental, 3-directional myocardial velocities with high temporal resolution (13.8 ms) was used to assess left ventricular motion. METHODS AND RESULTS: Radial, long-axis, and rotational myocardial velocities were acquired in 58 healthy volunteers (3 age groups, 29 women) in left ventricular basal, midventricular, and apical short-axis locations. For increased age, reduced (P<0.003) and prolonged long-axis and radial velocities (P<0.05) during diastole and reduced long-axis velocities (P<0.001) and apical rotation (P<0.005) during systole were found for both genders. Women demonstrated a reduced systolic twist (P=0.009), apical rotation (P=0.01), and systolic radial velocities (P<0.02) compared with men. Segmental analysis of long-axis motion with aging revealed differences in regional reduction of systolic (lateral 52% versus 30%) and diastolic (lateral 57% versus 41%) velocities in women compared with men. In basal segments, young women demonstrated higher long-axis velocities (+11% during diastole) than men, whereas this difference was reversed in older subjects (same segments, -20%). In addition, increased age resulted in a prolonged time to peak diastolic apical rotation (P<0.04) in women compared with men. CONCLUSIONS: Age and gender strongly influence regional myocardial motion. Tissue phase mapping provides a comprehensive quantitative analysis of all myocardial velocities with high temporal and spatial resolution. The knowledge of the detected age- and gender-related differences in myocardial motion is fundamental for further investigations of cardiac disease. Clinical Trial Registration- http://www.zks.uni-freiburg.de/uklreg/php/suchergebnis_all.php. Identifier: UKF001739.

Visualization of multidirectional regional left ventricular dynamics by high-temporal-resolution tissue phase mapping.

PURPOSE: To apply high-temporal-resolution tissue phase mapping (TPM) to derive a detailed representation of normal regional myocardial motion in a large cohort of 58 normal subjects (three age groups) and one patient with dilated cardiomyopathy. MATERIALS AND METHODS: Analysis included transformation of the acquired myocardial velocities into radial, circumferential, and long-axis motion components representing left ventricular (LV) function with a spatiotemporal resolution of 1.3 x 2.6 x 8 mm(3) and 13.8 msec, respectively. To compare multidirectional regional myocardial velocities between groups of subjects, a multisegment and multislice visualization model was employed. Regional myocardial motion was mapped onto the visualization model to display the current status of myocardial motion from base to apex as in-plane velocity vector fields in conjunction with color-coded long-axis plane motion. Moreover, correlation analysis was used to investigate regional differences in myocardial dynamics. RESULTS: Age-related changes in LV myocardial velocities resulted in significant differences of peak and time-to-peak velocities in the radial and long-axis directions. Correlation analysis revealed clearly visible regional differences in the temporal evolution of long-axis and circumferential velocities, particularly between the youngest and oldest age groups. Comparison of pathological LV motion with age-matched volunteers indicated marked regional alterations in myocardial velocities and dynamics. CONCLUSION: High-temporal-resolution TPM in combination with a schematic visualization model and correlation analysis permits the identification of local changes in myocardial velocities associated with different age groups and a common LV pathology.

Comparison of reconstruction intervals in routine ECG-pulsed 64-row-MSCT coronary angiography in frequency controlled patients.

PURPOSE: In light of the increasing use and acceptance of multislice computed tomography (MSCT) coronary angiography it was the purpose of this study to compare reconstruction intervals used in a routine ECG-pulsed MSCT coronary artery angiography setting with frequency controlled patients. METHODS: Examinations were performed on a Siemens Somatom Sensation 64 scanner with a total of 110 ml of contrast agent and ECG pulsing (interval from 40% to 70%) after oral application of a beta-blocker if the heart rate was higher than 65 bpm. All human subjects were referred for the evaluation of suspected coronary artery disease. Coronary artery segments were evaluated by two experienced radiologists in a consensus reading. A ranking of diagnostic image quality (from 1 (no evaluation possible) to 5 (excellent image quality)) was statistically evaluated by Wilcoxon Signed Rank Test. RESULTS: In 45 patients (30 male, 15 female, age 63.8 +/- 12.1 years) we detected a significant advantage of the 60% reconstruction interval over 40%, 50%, and 70% (for each p < 0.05). In cases of sudden arrhythmia or movement during the scan, additional reconstruction intervals within the ECG-pulsed reconstruction intervals remained necessary for diagnosis. CONCLUSION: In a routine diagnostic setting with frequency controlled patients and ECG pulsing the 60% reconstruction interval can be considered superior for the initial diagnosis in 64-row multislice computed tomography coronary angiography. However, further information can be derived from various reconstruction intervals such as 40% and 70%.