Page 26 - Assessing right ventricular function and the pulmonary circulation in pulmonary hypertension Onno Anthonius Spruijt

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subjects in whom both a baseline right heart catheterization and baseline CTPA were performed, were included in this study. In total, 51 precapillary PH patients were randomly selected. Precapillary PH was diagnosed according to the World Health Organization guidelines (mean pulmonary artery pressure > 25 mmHg and a pulmonary arterial wedge pressure ≤15 mmHg) *1+.
25 subjects who were referred to our center for suspected pulmonary hypertension and who appeared to have normal pulmonary artery pressures during right heart catheterization and without a history of left heart disease, were randomly chosen and used as controls.
The study was approved by The Medical Ethics Review Committee of the VU University Medical Center. The study does not fall within the scope of the Medical Research Involving Human Subjects Act (WMO). Therefore, the study was approved without requirement of a consent statement.
CTPA image acquisition
CTPA studies of the entire chest were performed on either a 4-slice multi-detector CT system (Somatom Volume Zoom, Siemens, Erlangen, Germany) or a 64-slice multi-detector CT system (Somatom Sensation, Siemens, Erlangen, Germany). 18 CTPA studies were performed on the 4-slice CT system and 58 CTPA studies were performed on the 64-slice CT system. The Dose Length Product (DLP) was 266 ± 118 mGy.cm.
For the 4-slice multi-detector CT scanning parameters were 140kV and 100mAs with dose modulation at a slice collimation of 4x1,0mm, a rotation time of 0,5 seconds and a pitch of 1,25 out of which 1,5mm axial slices with 1mm reconstruction increment were reconstructed. The series were acquired using bolus tracking within the PA at maximum inspiration after intravenous injection (4ml/s) of 100ml of a low-osmolar, non-ionic contrast agent with iodine concentration of 300mg/ml (Ultravist-300 Iopromide; Bayer Pharma AG, Berlin, Germany), using an injection pump through an 18g cannula preferably in the right antecubital vein.
For the 64-slice multidetector CT, a slice collimation of 32x0,6mm, a rotation time of 0,33 seconds and a pitch of 0,75 was used. The series were acquired using a test bolus (30ml at 6ml/s) with tracking in the PA and a scan bolus with calculated delay at maximum inspiration after intravenous injection (≤60ml at 6ml/s) of a low-osmolar, non-ionic contrast agent with a iodine concentration of 300mg/ml (Ultravist-300 Iopromide; Bayer Pharma AG, Berlin, Germany), using an injection pump through an 18g cannula mostly in the right antecubital vein.