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 > or =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 > or =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.

Non-electrocardiogram-gated multidetector-row computed tomography findings of cardiac pathology in oncologic patients.

Multidetector-row computed tomography (MDCT) plays an essential role in oncologic imaging as the modality of mapping out the treatment strategy at staging, assessing response to the treatment, and following up patient outcome after the treatment. Even without electrocardiogram gating, MDCT provides accurate information about the heart. In the group of oncologic patients, different tumoral and non-tumoral-related heart disorders can be found, for example, metastatic cardiac involvement (approximately 10% of patients with lung or breast cancer will develop metastases to the heart), paraneoplastic cardiac disorders, non-tumor-related heart disorders, and chemotherapy- and radiotherapy-related cardiac side effects. MDCT plays a role in the detection of these entities. We show the non-electrocardiogram-gated MDCT findings of oncology-related cardiac disorders to encourage radiologists to recognize and report cardiac findings in oncologic patients. Appropriate knowledge of tumoral and non-tumoral-related MDCT features allows a complete evaluation of oncologic patients with ancillary cardiac findings. An adequate knowledge of the patient's medical history, previous treatments, and concomitant illnesses is essential to interpret heart findings in oncologic patients who undergo MDCT.

Quantification of left ventricular function and mass in cardiac Dual-Source CT (DSCT) exams: comparison of manual and semiautomatic segmentation algorithms.

The purpose of our study was to evaluate reliability of left ventricular (LV) function and mass quantification in cardiac DSCT exams comparing manual contour tracing and a region-growing-based semiautomatic segmentation analysis software. Thirty-three consecutive patients who underwent cardiac DSCT exams were included. Axial 1-mm slices were used for the semiautomated technique, and short-axis 8-mm slice thickness multiphase image reconstructions were the basis for manual contour tracing. Left ventricular volumes, ejection fraction and myocardial mass were assessed by both segmentation methods. Length of time needed for both techniques was also recorded. Left ventricular functional parameters derived from semiautomatic contour detection algorithm were not statistically different from manual tracing and showed an excellent correlation (p<0.001). The semiautomatic contour detection algorithm overestimated LV mass (180.30+/-44.74 g) compared with manual contour tracing (156.07+/-46.29 g) (p<0.001). This software allowed a significant reduction of the time needed for global LV assessment (mean 174.16+/-71.53 s, p<0.001). Objective quantification of LV function using the evaluated region-growing-based semiautomatic segmentation analysis software is feasible, accurate, reliable and time-effective. However, further improvements are needed to equal results achieved by manual contour tracing, especially with regard to LV mass quantification.