Daniel Maxien MD, Presenter: Nothing to Disclose

Michael Ingrisch, Abstract Co-Author: Nothing to Disclose

Felix G. Meinel MD, Abstract Co-Author: Nothing to Disclose

Sven Florian Thieme MD, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Olaf Dietrich PhD, Abstract Co-Author: Nothing to Disclose

Konstantin Nikolaou MD, Abstract Co-Author: Speakers Bureau, Siemens AG Speakers Bureau, Bracco Group Speakers Bureau, Bayer AG

Assessing pulmonary perfusion using dynamic contrast-enhanced (DCE)-MRI is still limited in clinical routine due to the necessity of breath-holding. Hence, in the present study, an acquisition technique for the quantitative assessment of pulmonary perfusion in free breathing was investigated.

10 healthy, male volunteers underwent DCE-MRI on a 1.5 T scanner for the assessment of pulmonary perfusion, using an accelerated 3D view sharing gradient-echo sequence. Each volunteer was examined twice, once with the instruction to hold his breath during half expiration as long as possible and continue with shallow breathing; the second time during shallow free breathing. All Data were analyzed with an in-house developed software tool. The pulmonary parenchyma was segmented automatically. Pulmonary plasma flow (PPF) and pulmonary plasma volume (PPV) were determined pixel-wise, using a one-compartment model. Median values of each parameter map were recorded. Differences between both measurements were assessed using Wilcoxon rank tests.

All measurements were completed successfully. Neither parameter maps from free breathing nor from breath holding measurements suffered from major artifacts. The measured mean values of the PPV were (10.3±3.0)ml/100ml in breath hold technique and (12.7±3.9)ml/100ml during free breathing, respectively, i.e. the mean PPV in breath hold technique was significantly lower compared to the PPV during free breathing (p<0.05). No significant difference was observed between the both PPF measurements. The mean values of the PPF were (213±110)ml/100ml/min in breath hold technique and (240±114)ml/100ml/min during free breathing, respectively.

Free-breathing DCE-MRI appears to be suitable for the quantitative assessment of the pulmonary perfusion. The proposed quantification approach does not suffer from increased motion artifacts compared to the breath holding measurement. The increased PPV during free breathing is probably due to a physiologic decrease of the average lung volume under free-breathing conditions. Overall, free-breathing DCE-MRI is a promising technique for the assessment of pulmonary perfusion in various pathologies.

Patients suffering from lung diseases are frequently unable to hold their breath long enough for the assessment of pulmonary perfusion. This study demonstrates that breath holding may not be required.

Maxien, D, Ingrisch, M, Meinel, F, Thieme, S, Reiser, M, Dietrich, O, Nikolaou, K, Comparison of Breath-Hold and Free-Breathing Quantitative Pulmonary Perfusion MRI.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12028985.html