Quantitative evaluation of MR perfusion imaging using blood pool contrast agent in subjects without pulmonary diseases and in patients with pulmonary embolism

Abstract

• Recently introduced blood pool contrast agents improve MR evaluation of lung perfusion • Regional differences in lung perfusion indicating a gravitational and isogravitational dependency. • Focal areas of significantly decreased perfusion are detectable in pulmonary embolism.

Quantitative and Semiquantitative Measures of Regional Pulmonary Microvascular Perfusion by Magnetic Resonance Imaging and Their Relationships to Global Lung Perfusion and Lung Diffusing Capacity

“…In accordance with previous studies, PBF, PBV, SI and upslope in the posterior dependent lung were significantly higher than in the anterior non-dependent lung and, inversely, MTT was significantly shorter in the posterior than in the anterior lung parenchyma [7, 8, 33]. For example, by MRI measurement Ohno et al found comparable significant regional PBF differences of 148.1±17.3 ml blood per min and 100ml lung in the posterior and 97.6±13.7 ml blood per min and 100ml lung in the anterior lung parenchyma [8].…”

“…Absolute quantification of pulmonary parenchymal perfusion is challenging and time-consuming and requires specific imaging and contrast protocols as well as dedicated post-processing software [21, 33]. A close correlation between quantitative and semi-quantitative MRI parameters of pulmonary perfusion was observed in this study.…”

“…For example, by MRI measurement Ohno et al found comparable significant regional PBF differences of 148.1±17.3 ml blood per min and 100ml lung in the posterior and 97.6±13.7 ml blood per min and 100ml lung in the anterior lung parenchyma [8]. Similar to Hansch et al, PBF and PBV were higher in the superior than in the inferior lung [33]. Due to the bell-shape of the lungs the apical part of the lung on a central coronal slice is relatively close to the posterior chest wall.…”

“…Another limitation is the use of an extravascular MRI contrast agent, so that applying the indicator dilution theory may cause difficulties [34]. However, most studies use extravascular contrast agents and achieve comparable results with perfusion measures derived from PET imaging or MRI with blood pool contrast agents [6, 7, 33]. …”

Central and peripheral pulmonary vascular resistance: Implications for who should undergo pulmonary thromboendarterectomy

“…Flow partly depends on the three dimensional anatomy of the pulmonary arteries and obstructing clots, which is available from CT or magnetic resonance imaging, and the distal capillary resistance. Our analysis depends on knowing left and right selective pulmonary artery blood flow which is currently only available via magnetic resonance imaging(MRI) [15]. Knowledge of the left and right pulmonary artery flows enables the contribution from each lung to be assessed, as well as being vital for the calculation on the overall effect of thromboendarterectomy.…”