084 EFFECT OF CONTRAST DOSE, POST-CONTRAST ACQUISITION TIME, MYOCARDIAL REGIONALITY, CARDIAC CYCLE AND GENDER ON DYNAMIC-EQUILIBRIUM CONTRAST CMR MEASUREMENT OF MYOCARDIAL EXTRACELLULAR VOLUME
| Autor: | Glyn Coutts, Christopher A. Miller, Geoff J M Parker, S Zhou, Josephine H. Naish, Simon Ray, David J Clark, Matthias Schmitt |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Heart. 99:A52.1-A52 |
| ISSN: | 1468-201X 1355-6037 |
| Popis: | Introduction CMR techniques are increasingly being used to evaluate myocardial extracellular volume (ECV). In the most commonly applied method, ECV is quantified using haematocrit-adjusted myocardial and blood T1 values measured before and after gadolinium bolus. The technique is based on a two-compartment model, which assumes contrast kinetic effects to be negligible due to a dynamic equilibrium between blood and myocardium (Dynamic-Equilibrium CMR; DynEq-CMR). This study assessed the effect of contrast dose, post-contrast acquisition time, myocardial regionality, cardiac cycle and gender on DynEq-CMR ECV measurement. Methods 30 healthy volunteers (asymptomatic, no cardiovascular risk factors, normal examination and ECG) were prospectively split into 3 age and sex-matched groups (there were also no differences in mean eGFR, body surface area, heart rate, LV mass and volumetrics between groups): Group A received 0.10 mmol/kg Gd-DTPA, Group B 0.15 mmol/kg and Group C 0.20 mmol/kg. Mid-ventricular short-axis modified look locker inversion recovery (MOLLI) imaging was performed at 1.5T before, and at 2 min intervals between 2–20 min after, contrast administration, with same-day haematocrit measurement. MOLLI imaging was repeated in early systole (150 ms after R wave) pre- and at 10 min post-contrast. Resulting pixelwise T1 maps (figure 1; T1 maps at selected time-points are shown) were used to calculate ECV (Matlab). (Phantom studies performed prior to patient scanning determined T1 measurement accuracy and heart-rate correction algorithm). Results Pre-contrast myocardial (A 1051±49 ms; B 1045±49 ms; C 1040±43 ms; p=0.87) and blood (A 1678±98 ms; B 1645±118 ms; C 1686±101 ms; p=0.66) T1 times did not differ significantly between groups. Mean myocardial (A 542±65 ms; B 465±69 ms; C 407±55 ms; p Conclusions The small increase in ECV over time suggests that an incomplete dynamic equilibrium between blood and myocardium is achieved. DynEq-CMR-derived ECV varies according to contrast dose, myocardial region and gender. |
| Databáze: | OpenAIRE |
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