Article

[Reference values of MRI flow measurements of the pulmonary outflow tract in healthy children].

Institut für Diagnostische und Interventionelle Radiologie, Johann Wolfgang Goethe-Universität, Frankfurt am Main.
RöFo - Fortschritte auf dem Gebiet der R (impact factor: 2.76). 07/2004; 176(6):837-45. DOI:10.1055/s-2004-812959
Source: PubMed

ABSTRACT To provide reference values for MRI-based flow measurements in the main pulmonary artery in healthy children.
In 98 healthy children (age: 3 - 17 years, median: 11 years), the main pulmonary artery was examined using MRI-based flow measurements with high temporal resolution (9.6 ms per cardiac phase).
The acceleration time revealed a distinct age dependency and varied between 90 and 155 ms (mean: 124 ms +/- 14). The relative acceleration time (related to the RR-interval) varied between 12.7 and 27 % (mean: 18 % +/- 2.6). The mean values and the standard deviations for the determined values were as follows: cardiac output (5.4 l/min +/- 1.4), cardiac output normalized to the body surface area (4.2 [l/min]/m(2) +/- 0.8), average systolic flow velocity (66 cm/s +/- 12), maximum systolic flow (309 ml/s +/- 79), mean flow (110 ml/s +/- 30), distensibility of the wall of the main pulmonary artery (79 % +/- 26), peak velocity (96 cm/s +/- 15), pressure gradient along the pulmonary valve (3.8 mm Hg +/- 1.2), stroke volume (63.2 ml +/- 17.9), acceleration volume (23.7 ml +/- 8.7), maximum acceleration of flow (4924 ml/s(2) +/- 1431), and reverse volume (0.2 ml +/- 0.3).
The acquired values of reference are applicable to all pediatric patients and serve as a framework for the communication between the radiologist and the pediatric cardiologists. High temporal resolution of the measurement sequence is mandatory. Noticeable deviations of these values should induce additional (probably invasive) evaluation.

0 0
 · 
0 Bookmarks
 · 
14 Views
  • Source
    Article: Evaluation of a resistance-based model for the quantification of pulmonary arterial hypertension using MR flow measurements.
    Nasreddin Abolmaali, Uwe Seitz, Anoosh Esmaeili, Martin Kock, Daniel Radeloff, Hanns Ackermann, Thomas J Vogl
    [show abstract] [hide abstract]
    ABSTRACT: To establish an estimate for the mean pulmonary arterial pressure (mPAP) derived from noninvasive data acquired with magnetic resonance (MR) velocity-encoded sequences. In seven sedated pigs synchronous catheter-based invasive pressure measurements (IPM) and noninvasive MR were acquired in the main pulmonary artery (MPA) at different severities of pulmonary arterial hypertension (PAH) that were caused by infusion of thromboxane A2 (TxA2). The invasively measured mPAP was correlated with the noninvasive MR velocity data and linear combination equations (LCE) were computed. Intravenously applied TxA2 induced a dose dependent level of severity of PAH with an mPAP of up to 54 mmHg without systemic effects. The acceleration time (AT) measured with MR demonstrated the best correlation with the mPAP (r(2) = 0.75). The LCE with the highest correlation (R = 0.945, alpha < 0.01) between IPM and MR revealed a mean difference of 0, a SD of s = 4.66 and a maximal difference of 12.2 mmHg using the Bland-Altman analysis. Applying the identified LCE allowed the estimation of the mPAP in an acute and resistance-based model of PAH with high accuracy using noninvasive MR velocity-encoded sequences.
    Journal of Magnetic Resonance Imaging 09/2007; 26(3):646-53. · 2.70 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

98 healthy children
 
acceleration volume
 
average systolic flow velocity
 
body surface area
 
cardiac output
 
cardiac output normalized
 
distinct age dependency
 
main pulmonary artery
 
maximum acceleration
 
maximum systolic flow
 
measurement sequence
 
MRI-based flow measurements
 
peak velocity
 
pressure gradient
 
pulmonary valve
 
reference values
 
relative acceleration time
 
reverse volume
 
standard deviations
 
stroke volume