Cardiac function by MRI in congenital heart disease: impact of consensus training on interinstitutional variance.
ABSTRACT To investigate the impact of interinstitutional variance (=interobserver variance between institutions) for volumetric and flow cardiac MR (CMR) data and if training on image reading could improve bias.
In a three-center study, a total of 32 adults with repaired Tetralogy of Fallot and 23 controls underwent CMR using standardized protocols for ventricular volumes/mass (by transverse and short-axis cine-MRI) and pulmonary/aortic blood flow by velocity-encoded MRI (VEC-MRI). Data were analyzed blinded and independently in each institution by experienced readers. Interinstitutional variance was determined before/after training on consented guidelines for image analysis.
In patients, initial interinstitutional variability of right ventricular parameters was substantial but decreased by training. On transverse planes, variation coefficient for end-diastolic/systolic volumes and ejection fraction decreased from 22%, 19%, and 19% to 7%, 10%, and 8%, respectively (P < 0.025). Left-ventricular variation coefficients improved for end-diastolic and stroke volumes from 8% and 15% to 4% and 6%, respectively (P < 0.007). For short-axis volumetry training resulted in narrowed limits of confidence. Variability did not significantly change in the controls. There was no significant difference between transverse/short-axis MRI. Interinstitutional variance for VEC-MRI in patients/controls was low (<4%).
Interinstitutional variance is an important source of variability in volumetric but not in flow CMR. Such variance can be reduced effectively by consented training.
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ABSTRACT: Cardiovascular magnetic resonance (CMR) has taken on an increasingly important role in the diagnostic evaluation and pre-procedural planning for patients with congenital heart disease. This article provides guidelines for the performance of CMR in children and adults with congenital heart disease. The first portion addresses preparation for the examination and safety issues, the second describes the primary techniques used in an examination, and the third provides disease-specific protocols. Variations in practice are highlighted and expert consensus recommendations are provided. Indications and appropriate use criteria for CMR examination are not specifically addressed.Journal of Cardiovascular Magnetic Resonance 06/2013; 15(1):51. · 4.44 Impact Factor
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ABSTRACT: Cardiac magnetic resonance (CMR) imaging is the preferred method to measure right ventricular (RV) volumes and ejection fraction (RVEF). This study aimed to determine the impact of excluding trabeculae and papillary muscles on RV volumes and function in patients with RV pressure and/or volume overload and healthy controls and its reproducibility using semi-automatic software. Eighty patients (pulmonary hypertension, transposition of the great arteries after arterial switch operation and after atrial switch procedure and repaired Tetralogy of Fallot) and 20 controls underwent short-axis multislice cine CMR. End diastolic volume (EDV), end systolic volume (ESV), RV mass and RVEF were measured using 2 methods. First, manual contour tracing of RV endo- and epi-cardial borders was performed. Thereafter, trabeculae were excluded from the RV blood volume using semi-automatic pixel-intensity based software. Both methods were compared using a Student T test and 25 datasets were re-analyzed for reproducibility. Exclusion of trabeculae resulted in significantly decreased EDV; ranging from -5.7 ± 1.7 ml/m(2) in controls to -29.2 ± 6.6 ml/m(2) in patients after atrial switch procedure. RVEF significantly increased in all groups, ranging from an absolute increase of 3.4 ± 0.8 % in healthy controls to 10.1 ± 2.3 % in patients after atrial switch procedure. Interobserver agreement of method 2 was equal to method 1 for RVEDV, RVESV and RVEF and superior for RV mass. In patients with overloaded RVs exclusion of trabeculae from the blood volume results in a significant change in RV volumes, RVEF and RV mass. Exclusion of trabeculae is highly reproducible when semi-automatic pixel-intensity based software is used.The international journal of cardiovascular imaging 01/2014; · 2.15 Impact Factor
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ABSTRACT: Cardiac magnetic resonance imaging (CMR) has evolved over the past 20 years from a research-based imaging modality to an indispensable routine procedure in cardiac diagnostics. In addition to the morphological representation of cardiac anatomy, whereby only noninvasive multidetector computed tomography (MDCT) is superior, another strength of CMR is the assessment of cardiac function and tissue differentiation. This requires that the radiologist performing the examination and analyzing the results has good knowledge of cardiac and thoracic anatomy and a detailed knowledge of the various cardiovascular diseases, hemodynamics, and pathophysiology. CMR reliably allows determination of a range of easy to determine quantitative parameters such as ventricular ejection fraction and also the valvular regurgitation fraction, which allows objective assessment of cardiac function. Especially the possibility to differentiate inflamed, viable, and ischemic tissue using adenosine stress MRI in the last 10 years has led to routine use of CMR. Even compared to competing nuclear medicine procedures, CMR is important for treatment decision-making and for prognosis estimation, thus, making it an indispensable component of cardiovascular diagnostics.Der Radiologe 11/2013; 53(11):1033-1052. · 0.47 Impact Factor