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  • Ovid Technologies (Wolters Kluwer Health)  (2)
  • Englisch  (2)
  • 2000-2004  (2)
  • 2004  (2)
Materialart
Verlag/Herausgeber
  • Ovid Technologies (Wolters Kluwer Health)  (2)
Sprache
  • Englisch  (2)
Erscheinungszeitraum
  • 2000-2004  (2)
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  • 2004  (2)
  • 1
    In: Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 109, No. 16 ( 2004-04-27), p. 1987-1993
    Kurzfassung: Background— Flow quantification in real time by phase-contrast MRI (PC-MRI) may provide unique hemodynamic information in congenital heart disease, but available techniques have important limitations. We sought to validate a novel real-time magnetic resonance flow sequence in children. Methods and Results— In 14 pediatric patients (mean age 5.2±2.0 years) with cardiac left-to-right shunt, pulmonary (Q p ) and aortic (Q s ) flow rates were determined by nontriggered free-breathing real-time PC-MRI with single-shot echo-planar imaging combined with sensitivity encoding, which yielded 25 phase images per second at 2.7×2.7-mm in-plane resolution (field of view 30×34 cm 2 ). Over a 9.5-second period that included 2 to 5 respiratory cycles, 16.6±2.6 subsequent stroke volumes (range 13 to 22) were acquired in each vessel. Results were compared with conventional retrospectively ECG-gated PC-MRI. Mean Q p /Q s by conventional PC-MRI was 1.91±0.64, and it was 1.94±0.68 (mean±SD) by real-time PC-MRI. For blood flow rate through pulmonary artery and aorta, we found differences of 2% to 3% (Bland-Altman analysis), with lower limits of agreement of −11% to −13% (mean−2 SD) and upper limits of 18% to 19% (mean+2 SD), which demonstrated good agreement between both methods. Mean difference for Q p /Q s was 1%, with limits of agreement ranging between −18% and 22% (mean±2 SD). High repeatability but some flow overestimation was observed in vitro (pulsatile flow phantom) with real-time PC-MRI, whereas conventional PC-MRI was accurate. Beat-to-beat stroke-volume variation was 6.1±2.3% in vivo and 3.7±0.3% in vitro. Conclusions— Beat-to-beat quantification of pulmonary and aortic flows and hence left-to-right shunt within a few seconds is reliable by nontriggered real-time PC-MRI with echo-planar imaging and sensitivity encoding. Good spatial/temporal resolution and a large field of view may render the sequence valuable for multiple applications in congenital heart disease.
    Materialart: Online-Ressource
    ISSN: 0009-7322 , 1524-4539
    Sprache: Englisch
    Verlag: Ovid Technologies (Wolters Kluwer Health)
    Publikationsdatum: 2004
    ZDB Id: 1466401-X
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    In: Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 110, No. 2 ( 2004-07-13), p. 163-169
    Kurzfassung: Background— Operator-independent isotropic 3D MRI may greatly simplify the assessment of complex morphology in congenital heart disease. We sought to evaluate the reliability of this new approach. Methods and Results— In 31 adolescent and adult patients (age, 6 to 42 years; median, 16 years) with congenital heart disease, cardiac morphology was determined with free-breathing (navigator-gated), isotropic, 3D steady-state free-precession (3D SSFP) MRI and independently evaluated by 2 observers. Cardiac diagnoses and multiple distance measurements were compared with conventional MR reference sequences (ie, spin-echo, cine gradient-echo, contrast-enhanced MR angiography) and with echocardiography/cine cardioangiography or surgery. Of the 31 patients, 24 had native congenital heart defects or residual defects after repair that warranted immediate treatment. None of these defects was missed by 3D SSFP. Novel diagnostic issues were discovered in 4 of 31 patients (coronary anomalies, n=3; left juxtaposition of the right atrial appendage in double-outlet right ventricle and transposition of the great arteries, 1). For sizes of valves and vessels, we found minor mean differences of −1.1 to 1.6 mm, with SD ranging from 1.2 to 2.9 mm, demonstrating overall good agreement with standard MRI (Bland-Altman analysis). Interobserver variability of 3D SSFP distance measures was low; mean differences ranged from −1.5 to 1.0 mm, and SD ranged from 0.8 to 2.5 mm. Scatter was lower for extracardiac than intracardiac measures. Conclusions— In adolescents and adults, isotropic 3D SSFP MRI allows reliable assessment of complex cardiac morphology. Distance measurements are accurate and reproducible. Thus, a single operator-independent acquisition may substitute for conventional 2D MRI sequences to accelerate and simplify MR scanning in congenital heart disease.
    Materialart: Online-Ressource
    ISSN: 0009-7322 , 1524-4539
    Sprache: Englisch
    Verlag: Ovid Technologies (Wolters Kluwer Health)
    Publikationsdatum: 2004
    ZDB Id: 1466401-X
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
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