Maria Arraiza

Assessment of left atrial volumes and function in orthotopic heart transplant recipients by dual-source CT: comparison with MRI.

Introduction:To compare left atrial performance with dual-source CT (DSCT) with respect to magnetic resonance imaging (MRI) in orthotopic heart transplant recipients. Methods:Twenty-nine consecutive heart transplant recipients (27 male; mean age 64.1 ± 13 years; mean time from transplantation 122.8 ± 69.7 months) referred for exclusion of cardiac allograft vasculopathy underwent cardiac DSCT and MRI. Standard biatrial technique was employed in 13 subjects whereas 16 were transplanted after the bicaval technique. Axial 5-mm slice-thickness DSCT datasets reconstructed in 5% steps of the cardiac cycle and axial 5-mm SSFP-MRI images were analyzed. Two blinded readers manually traced left atrial contours in random order to estimate end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF). Parameters were compared with a paired sample Student t test. Concordance correlation coefficient (CCC) was calculated to determine measurement agreement between techniques and observers. Results:Left atrial volumes were significantly higher with cardiac DSCT (EDV: 170.9 ± 78.1 mL; ESV: 139.5 ± 76.6 mL) than with MRI (EDV: 158.2 ± 72.5 mL; ESV: 124.2 ± 68.2 mL), whereas left atrial EF was lower with DSCT (EF: 20.8% ± 7.5% vs. 23.6% ± 7.7%) (P < 0.05). Measurement agreement between DSCT and MRI was excellent for all parameters (CCC ≥0.82). Individuals operated with the biatrial anastomosis technique presented significantly higher left atrial volumes and lower EF compared with subjects with bicaval anastomosis. Interobserver agreement was excellent for all parameters (CCC ≥0.80). Conclusion:Even if DSCT slightly overestimates left atrial volumes with respect to MRI, results remain clinically valid. Bicaval surgical technique offers improved left atrial performance compared with standard biatrial anastomosis. DSCT may be used as a reliable tool to estimate left atrial parameters in orthotopic heart transplant recipients.

Low-dose volumetric computed tomography for quantification of emphysema in asymptomatic smokers participating in an early lung cancer detection trial.

Purpose High-resolution computed tomography (CT) is a validated method to quantify the extent of pulmonary emphysema. In this study, we assessed the reliability of low-dose volumetric CT (LDCT) for the quantification of emphysema and its correlation with spirometric indices of airway obstruction. Materials and Methods The study population consisted of 102 consecutive current and former smokers participating in a lung cancer screening trial. All subjects underwent spirometry testing and LDCT at entry and a LDCT after 12 months. The extent of emphysema was estimated by 2 techniques; by using the lung attenuation threshold analysis and by visual assessment of the 2 independent radiologists. The reproducibility of these determinations was assessed using test-retest reliability and κ coefficient of agreement. The correlation of LDCT-based emphysema determinations with indices of airway obstruction on spirometry was also calculated. Results Eighty percent of the participants were male, with a mean (standard deviation) age of 54.5 (7.5) years, and median pack-years (interquartile range) of 20 (24). Test-retest reliability of all LDCT-based emphysema determinations was very good (intraclass correlation coefficient of 0.92 for the volume of emphysema, and 0.93 for the emphysema index or emphysema volume/total lung volume). Similarly, there was an excellent interrater agreement for visual assessment of emphysema (κ coefficient=0.91). Higher volumes of emphysema measured quantitatively or visually significantly correlated with spirometric markers of airway obstruction. Conclusions Volumetric LDCT is a reliable and valid technique for the quantification of emphysema in asymptomatic smokers.

Dual-Source CT for Visualization of the Coronary Arteries in Heart Transplant Patients with High Heart Rates

OBJECTIVE The purpose of this study was to evaluate the quality of dual-source CT images of the coronary arteries in heart transplant recipients with high heart rates. SUBJECTS AND METHODS Contrast-enhanced dual-source CT coronary angiography was performed on 23 heart transplant recipients (20 men, three women; mean age, 61.1 +/- 12.8 years). Data sets were reconstructed in 5% steps from 30% to 80% of the R-R interval. Two blinded independent readers using a 5-point scale (0, not evaluative; 4, excellent quality) assessed the quality of images of coronary segments. RESULTS The mean heart rate during scanning was 89.2 +/- 10.4 beats/min. Interobserver agreement on the quality of images of the whole coronary tree was a kappa value of 0.78 and for selection of the optimal reconstruction interval was a kappa value of 0.82. The optimal reconstruction interval was systole in 17 (74%) of the 23 of heart transplant recipients. At the best reconstruction interval, diagnostic image quality (score >or= 2) was obtained in 92.1% (303 of 329) of the coronary artery segments. The mean image quality score for the whole coronary tree was 3.1 +/- 1.01. No significant correlation between mean heart rate (rho = 0.31) or heart rate variability (rho = 0.23) and overall image quality score was observed (p = not significant). CONCLUSION Dual-source CT acquisition yields coronary angiograms of diagnostic quality in heart transplant recipients. Mean heart rate and heart rate variability during scanning do not have a negative effect on the overall quality of images of the coronary arteries.

Dual-source CT in heart transplant recipients: quantification of global left ventricular function and mass.

Objective To evaluate reliability of global left ventricular (LV) function and mass quantification in heart transplant recipients undergoing cardiac dual-source computed tomography examinations by means of manual contour tracing and using a region-growing–based semiautomatic segmentation analysis software tool. Materials and Methods Twenty-six consecutive heart transplant recipients undergoing cardiac dual-source computed tomography examinations with tube current modulation were included. Double-oblique short-axis 8-mm slice thickness multiphase image reconstructions were used for manual contouring and axial 0.75 mm slices were used for the semiautomated segmentation. LV ejection fraction, end-diastolic volume, end-systolic volume, stroke volume, cardiac output, and myocardial mass were assessed by both segmentation methods. Length of time needed for manual contour tracing and for the semiautomated software was recorded. Contrast-to-noise ratio was calculated in end-diastolic and end-systolic images. Results No statistically significant differences were observed in LV functional parameters derived from semiautomatic contour detection algorithm as compared with manual contouring, with excellent agreement (concordance-correlation coefficient ≥0.80). The semiautomated contour detection algorithm overestimated LV mass (mean difference 12.84±3.39) (P<0.001). The evaluated software allowed to quantify LV parameters in a significantly shorter period of time (mean difference 201.68±121.98 s, P<0.001). Contrast-to-noise ratio in end-systole and end-diastole statistically differed (mean difference 5.29±2.94 Hounsfield units; P<0.01) but did not significantly hamper the semiautomated segmentation. Conclusions Objective quantification of LV volumes using the evaluated semiautomated segmentation software is precise, reproducible, and time effective.

Coronariografía mediante tomografía computarizada de doble fuente: calidad de imagen e intervalo de reconstrucción óptimo

OBJECTIVE To evaluate the effect of average heart rate on the quality of images of the coronary arteries and to determine the optimal reconstruction interval in nonselected patients undergoing DSCT coronary imaging. MATERIALS AND METHODS We studied 28 consecutive subjects (26 men, 2 women; mean age 60+/-12 years) undergoing contrast-enhanced DSCT (Somatom Definition, Siemens) coronary angiography. Data sets were reconstructed in 5% steps from 30% to 80% of the R-R interval. Two blinded independent readers assessed the image quality of the whole coronary tree and of each coronary artery using a four-point scale (1: impossible to evaluate, 4: excellent quality). RESULTS Mean heart rate during scanning was 73.1+/-14.8 bpm (range, 49-107 bpm). In the best reconstruction interval, excellent diagnostic image quality (score 4) was achieved for 98.8% (83/84) of coronary arteries. Very good interobserver agreement was observed for image quality rating (kappa=0.77) and for selection of the optimal reconstruction interval (kappa=0.86). Mean image quality score for the whole coronary tree was 2.84+/-0.31. No significant correlation was found between the average heart rate and the mean quality scores (r=0.108). No significant differences were found in the quality of images of the coronary arteries in systolic and diastolic reconstructions in each patient. CONCLUSIONS DSCT makes it possible to obtain excellent coronary angiograms independent of the heart rate. Reconstructions can be obtained in either the diastolic or systolic phase without significant differences in image quality, even at high heart rates.

Assessment of left ventricular parameters in orthotopic heart transplant recipients using dual-source CT and contrast-enhanced echocardiography: Comparison with MRI

OBJECTIVES To establish the accuracy and reliability of cardiac dual-source CT (DSCT) and two-dimensional contrast-enhanced echocardiography (CE-Echo) in estimating left ventricular (LV) parameters with respect to cardiac magnetic resonance imaging (CMR) as the reference standard. METHODS Twenty-five consecutive heart transplant recipients (20 male, mean age 62.7±10.4 years, mean time since transplantation 8.1±5.9 years) were prospectively recruited. Two blinded readers independently assessed LV ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), and stroke volume (SV) for each patient after manual tracing of the endo- and epicardial contours in DSCT, CE-Echo and CMR cine images. Students t-test for paired samples for differences, and Bland and Altman plots and Lins concordance-correlation coefficients (CCC) for agreement were calculated. RESULTS There was no statistical difference between left ventricular parameters determined by DSCT and CMR. CE-Echo resulted in significant underestimation of left ventricular volumes (mean difference EDV: 15.94±14.19 ml and 17.1±17.06 ml, ESV: 8.5±9.3 and 7.32±9.14 ml with respect to DSCT and CMR), and overestimation of EF compared with the cross-sectional imaging modalities (3.78±8.47% and 2.14±8.35% with respect to DSCT and CMR). Concordance correlation coefficients for LV parameters using DSCT and CMR were higher (CCC≥0.75) than CCC values observed between CE-Echo and DSCT- or CMR-derived data (CCC≥0.54 and CCC≥0.49, respectively). Interobserver agreement was higher for DSCT and CMR values (CCC≥0.72 and CCC≥0.87, respectively). CONCLUSION In orthotopic heart transplantation cardiac DSCT allows accurate and reliable estimation of LV parameters compared with CMR, whereas CE-Echo seems to be insufficient to obtain precise measurements.

Allograft morphology and function in heart transplant recipients surviving more than 15 years by magnetic resonance imaging and dual-source computed tomography.

OBJECTIVE Cardiac allograft vasculopathy and late graft failure are the main limiting factors of long-term success of heart transplantation, and little is known about graft function in the long-term survivors. The aim of this study was to assess the ventricular function and the allograft vasculopathy in long-term survivors (>15 years) with the cardiac magnetic resonance imaging (MRI) and dual-source computed tomography (DSCT) coronary angiogram. METHODS In our database, 34 cardiac recipients have more than 15 years of follow-up and were evaluated for this study; 22 (65%) of them were enrolled. Mean age at transplant was 46 ± 13.5 years, mean donor age was 28.5 ± 10.1 years, and mean graft ischemic time was 189 ± 58 min. Mean follow-up was 18.5 ± 2.4 years (range 15-22). All patients underwent cardiac MRI and DSCT. RESULTS Mean left ventricular (LV) volumes indexed to the body surface area (BSA) were within normal range: the end-diastolic volume/BSA was 61 ± 16 ml m(-2), end-systolic volume/BSA was 22 ± 15 ml m(-2), stroke volume/BSA was 38 ± 6 ml m(-2), LV mass/BSA: 72 ± 18 g m(-2), and mean ejection fraction (EF) was 0.59 ± 0.08. Two patients (9%) showed a global cardiac hypokinesia and two other patients (9%) showed akinesia of one segment. At DSCT, 41% of patients had a strictly normal coronary angiogram, 41% had wall thickening and 18% presented a least one >60% stenosis. CONCLUSIONS Cardiac MRI and DSCT coronary angiogram revealed a normal graft function and morphology after more than 15 years of transplantation. However, a certain number of patients have significant cardiac allograft vasculopathy and another consistent group has initial disease. These patients deserve further follow-up and tailoring of the immunosuppressive regimen.

Three-Dimensional Transvaginal Sonography and Magnetic Resonance Imaging for Local Staging of Cervical Cancer An Agreement Study

To evaluate the agreement of clinical examination, 2‐dimensional (2D) sonography, and 3‐dimensional (3D) sonography with magnetic resonance imaging (MRI) for local staging of cervical cancer.

Fases de reconstrucción y exactitud de la tomografía computarizada para cuantificar la función y masa ventricular izquierda

PURPOSE To compare the accuracy of cardiac dual-source CT (DSCT) reconstructions obtained at 5% and 10% of the cardiac cycle and MRI for quantifying global left ventricular (LV) function and mass in heart transplant recipients. MATERIAL AND METHODS We prospectively included 23 heart transplant recipients (21 male, mean age 60±11.7 years) who underwent cardiac DSCT and MRI examinations. We compared LV parameters on cardiac DSCT reconstructions obtained at 5% (0%-95%) and 10% (0%-90%) intervals of the cardiac cycle and on double-oblique short-axis MR images. We determined ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), and myocardial mass using commercially available semiautomated segmentation analysis software for DSCT datasets and conventional manual contour tracing for MR studies. RESULTS Using different reconstruction intervals to quantify LV parameters at DSCT resulted in non-significant differences (P>.05). Compared to MRI, DSCT slightly overestimated LV-EDV, ESV, and mass when both 5% (11.5±25.1ml, 6.8±10.9ml, and 28.3±21.6g, respectively) and 10% (mean difference 15.3±26.3ml, 7.4±11.5ml, and 29.3±18.7g, respectively) reconstruction intervals were used. DSCT and MRI estimates of EF and SV were not significantly different. CONCLUSION In heart transplant recipients, DSCT allows reliable quantification of LV function and mass compared with MRI, even using 10% interval reconstructions.

Morphological and functional evaluation of intrapericardial cyst as a cause of severe right heart failure: dual source computed tomography and magnetic resonance imaging.

A case of an intrapericardial cyst causing heart failure due to right ventricular compression is presented. Characterization of the lesion and its repercussion on right ventricular function by means of state-of-the-art dual source computed tomography (DSCT) and magnetic resonance imaging (MRI) is shown. The diagnosis of intrapericardial cyst was confirmed after surgical excision and biopsy. Usefulness of these noninvasive techniques for the diagnosis of this rare entity is emphasized.