Purpose:To establish normal ranges of left ventricular (LV) and right ventricular (RV) dimensions as determined by the current pulse sequences in cardiac magnetic resonance imaging (MRI). Materials and Methods:Sixty normal subjects (30 male and 30 female; age range, 20 -65) were examined; both turbo gradient echo (TGE) and steady-state free precession (SSFP) pulse sequences were used to obtain contiguous short-axis cine data sets from the ventricular apex to the base of the heart. The LV and RV volumes and LV mass were calculated by modified Simpson's rule.Results: Normal ranges were established and indexed to both body surface area (BSA) and height. There were statistically significant differences in the measurements between the genders and between TGE and SSFP pulse sequences. For TGE the LV end-diastolic volume (EDV)/BSA (mL/m 2 ) in males was 74.4 Ϯ 14.6 and in females was 70.9 Ϯ 11.7, while in SSFP in males it was 82.3 Ϯ 14.7 and in females it was 77.7 Ϯ 10.8. For the TGE the LV mass/ BSA (g/m 2 ) in males was 77.8 Ϯ 9.1 and in females it was 61.5 Ϯ 7.5, while in SSFP in males it was 64.7 Ϯ 9.3 and in females it was 52.0 Ϯ 7.4. For TGE the RV EDV/BSA (mL/ m 2 ) in males was 78.4 Ϯ 14.0 and in females it was 67.5 Ϯ 12.7, while in SSFP in males it was 86.2 Ϯ 14.1 and in females it was 75.2 Ϯ 13.8. Conclusion:We have provided normal ranges that are gender specific as well as data that can be used for age-specific normal ranges for both SSFP and TGE pulse sequences. CARDIAC MAGNETIC RESONANCE IMAGING (MRI) has been shown to be an accurate and reproducible tool for the estimation of both left ventricular (LV) and right ventricular (RV) measurements (1-8). Currently, the two pulse sequences, which are in common clinical and research use for acquisition of volumes data sets, are segmented k-space turbo gradient echo (TGE) and the more recent steady-state free precession (SSFP) technique. The latter sequence has been validated in animal studies (9). TGE acquisition has been compared to previously validated sequences with excellent correlation (7).Lorenz et al published the first normal range for cardiac MRI LV mass (g) and volumes, utilizing a conventional cine gradient echo sequence performed with free breathing (10). Another normal range for TGE with breath holding was developed by Marcus et al (11). There is a difference between the values obtained by the two groups. Lorenz et al report a mean LV mass of 178 Ϯ 31 for men (N ϭ 47) and of 125 Ϯ 26 for women (N ϭ 28), while Marcus et al report a mean LV mass of 142 Ϯ 20 for men (N ϭ 32) and 102 Ϯ 15.9 for women (N ϭ 29). These differences remained after indexation to body surface area (BSA). Therefore, there is a need for further work to establish a normal range for the TGE pulse sequence, which remains in common use. Furthermore, because of improved delineation of the endocardial borders and faster acquisition time, it is anticipated that SSFP pulse sequences will be the most frequently used technique in the future. Comparative values for ventricular volumes based...
Magnetic resonance (MR) imaging is an important tool in the evaluation of cardiac neoplasms. T1-weighted, T2-weighted, and gadolinium-enhanced sequences are used for anatomic definition and tissue characterization, whereas cine gradient-echo imaging is used to assess functional effects. Recent improvements in pulse sequences for cardiac MR imaging have led to superior image quality, with reduced motion artifact and improved signal-to-noise ratio and tissue contrast. Although there is some overlap in the MR imaging appearances of cardiac tumors, particularly of primary malignancies, differences in characteristic locations and features should allow confident differentiation between benign and malignant tumors. Indicators of malignancy at MR imaging are invasive behavior, involvement of the right side of the heart or the pericardium, tissue inhomogeneity, diameter greater than 5 cm, and enhancement after administration of gadolinium contrast material (as a result of higher tissue vascularity). Concomitant pericardial or pleural effusions are rare in benign processes but occur in about 50% of cases of malignant tumors. MR imaging offers improved resolution, a larger field of view, and superior soft-tissue contrast compared with those of echocardiography, suggesting that knowledge of the MR imaging features of cardiac neoplasms is important for accurate diagnosis and management.
Purpose:To compare right ventricular (RV) volume measurements and their reproducibility between axial and short axis orientation acquisition techniques. Materials and Methods:Measurements of RV volumes from data sets acquired in axial and short axis orientations were compared in 20 normal subjects. The observer variabilities were assessed and the left ventricle (LV) and RV stroke volumes (SV) were compared.Results: There was a significant and systematic difference in the EDV and ESV volumes between the axial and short axis methods. The latter method resulted in larger volumes (mean bias EDV 7.5 Ϯ 13.2, 4.7% difference; ESV 7.2 Ϯ 8.6, 10.7% difference). The axial method had lower intra-and interobserver variability than the short axis method. The standard deviation of the difference (SDD) and the limits of agreement were consistently lower for the axial method. The mean differences between LV and RV stroke volumes expressed as mean Ϯ 1 SD (r 2 ϭcorrelation coefficient) were: axial 7.6 Ϯ 9.1 (r 2 ϭ 0.93); and short axis 7.4 Ϯ 10.8 (r 2 ϭ 0.90). Conclusion:There is a significant systematic difference between volumes measured using the two different orientations. The axial orientation resulted in better inter-and intraobserver reproducibility. MAGNETIC RESONANCE IMAGING (MRI) is considered to be the most accurate imaging method for the evaluation of right ventricular (RV) volumes (1,2). MRI measurement of RV volumes has been validated with close correlation between RV and left ventricular (LV) stroke volumes and between RV stroke volumes and tricuspid flow measurements (3). The advantage of MRI is that it can offer unrestricted choice of scanning planes combined with three-dimensional coverage of the whole heart. Other imaging modalities, such as echocardiography and right ventriculography, are limited by the complex shape of the RV (4). Right ventriculography and tomographic-gated blood pool scintigraphy involve exposure to ionizing radiation (5).There is increased demand for assessment of the RV volumes and function, particularly in the long-term follow-up of patients with congenital heart disease (CHD) (6 -8). Serial imaging follow-up, to detect progressive RV dilation and functional deterioration, needs to be accurate and reproducible (9).MRI measurements of the RV volumes were originally validated in data acquired in the axial (transverse) orientation (3). However, it is currently common practice to acquire data for RV volumetric analysis in an axis aligned along the LV short axis. This has some potential advantages over the axial method. First, only one data set is required for both LV and RV measurements. Second, in the axial orientation, the partial volume effect of blood and myocardium on the inferior wall of the RV can make it difficult to identify the blood/myocardial boundary. This effect is particularly seen with segmented-k-space turbo gradient echo (TGE) pulse sequences that are limited by reduced contrast between the blood and myocardium at the endocardial border. This is because the contrast is larg...
Steady-state free precession imaging is a promising technique for cardiac magnetic resonance imaging (MRI), as it provides improved blood/myocardial contrast in shorter acquisition times compared with conventional gradientecho acquisition. The better contrast could improve observer agreement and automatic detection of cardiac contours for volumetric assessment of the ventricles, but measurements might differ from those obtained using conventional methods. We compared volumetric measurements, observer variabilities, and automatic contour detection between a steady-state free precession imaging sequence (BFFE ؍ balanced fast field echo) and segmented k-space gradient-echo acquisition (TFE ؍ turbo field echo) in 41 subjects. With BFFE, significantly higher end-diastolic and end-systolic volumes and lower wall thickness, ventricular mass, ejection fraction, and wall motion were observed (P < 0.0001), while interobserver variabilities were lower and automatic contour detection of endocardial contours was more successful. We conclude that the improved image quality of BFFE reduces the observer-
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