Markus Weininger MD, Presenter: Nothing to Disclose

Matthias Adolf Justus Beissert MD, Abstract Co-Author: Nothing to Disclose

Markus Oechsner, Abstract Co-Author: Nothing to Disclose

Herbert Koestler PhD, Abstract Co-Author: Nothing to Disclose

Dietbert Hahn MD, Abstract Co-Author: Nothing to Disclose

Meinrad Johannes Beer MD, Abstract Co-Author: Nothing to Disclose

To evaluate contrast-enhanced pulmonary perfusion, comparing a pre-bolus approach to single bolus measurements using different contrast agent quantities.

11 healthy volunteers (8 male, 3 female, mean age 25±2 years) were examined using a 1.5T MR scanner. Perfusion images were acquired in expiratory breath-holds with a saturation-recovery TrueFISP. We compared four different first-pass boluses (0.5/1.0/2.0/3.0ml) and two different pre-bolus approaches (2.0/3.0ml). A region of interest (ROI) was positioned in the left pulmonary artery to evaluate the arterial-input-function (AIF). AIF for the 2.0ml and 3.0ml boluses was constructed from 1.0ml AIF. Signal-time courses of the lung parenchyma were taken from ROIs placed over the right and left lung. Perfusion values were calculated deconvoluting the lung’s signal-time courses with the AIF and an exponential function as residuum. Quantitative perfusion maps were generated fitting the lung pixel by pixel. Lung volume (2D-HASTE) and heart-time-volume (TrueFISP) were measured to derive the global lung perfusion (GLP) as correlation.

Mean perfusion values were as follows: 0.5ml: 190±73ml/min/100ml; 1.0ml: 221±68ml/min/100ml; 2.0ml: 263±87ml/min/100ml; 3.0ml: 365±148ml/min/100ml; pre-bolus 1.0ml/2.0ml: 192±70ml/min/100ml; pre-bolus 1.0ml/3.0ml: 165±52ml/min/100ml. Mean value for GLP was 187±34ml/min/100ml. Single bolus measurements with contrast quantities ≥2.0ml result in increased pulmonary perfusion, due to saturation effects of the AIF. Calculated perfusion maps resulted in improved fit quality and smoother maps using the pre-bolus approach.

Lung perfusion using single boluses (0.5ml, 1.0ml) and pre-boluses (2.0ml, 3.0ml) display a high-grade correlation to GLP. Furthermore the pre-bolus technique seems to be preferable to single bolus approaches as it achieved smoother and less noisy perfusion maps due to higher SNR.

Contrast-enhanced MRI seems to accurately assess pulmonary perfusion of healthy human lungs. It offers a potentially noninvasive assessment of lung diseases without radiation exposure.

Weininger, M, Beissert, M, Oechsner, M, Koestler, H, Hahn, D, Beer, M, Quantitative Perfusion Measurements of the Healthy Human Lung Using Contrast-enhanced MRI.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5001657.html