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Purpose: To demonstrate the feasibility of pulmonary MRA in living rodents., Materials and Methods: A three-dimensional (3D) gradient echo sequence was adapted to perform a time-of-flight (TOF) angiography of rat lung. Angiogram with a spatial resolution of 195 x 228 x 228 microm(3) was acquired in around 33 minutes. The method was then applied in animals before and after pulmonary embolism (PE) induction. Section of the proximal right pulmonary artery was measured and compared between the two populations., Results: Good quality images were obtained with a contrast-to-noise ratio (CNR) of 9 +/- 3 in the proximal part of the pulmonary artery. Cross-section areas of the right main artery are statistically different before (3.45 +/- 0.69 mm(2)) and after induction of PE (4.3 +/- 0.86 mm(2))., Conclusion: This noninvasive tool permits angiogram acquisition at around 200 microm spatial resolution and objective distinction between healthy and embolized arteries., ((c) 2006 Wiley-Liss, Inc.)

Objective: The aims of this study were to investigate absolute assessment of aortic valve area (AVA), before surgery for aortic stenosis, using cardiovascular magnetic resonance (CMR) in comparison with transesophageal echocardiography (TEE) and with effective AVA indirectly obtained by routine techniques i.e. transthoracic echocardiography (TTE) and cardiac catheterisation., Materials and Methods: Absolute AVA planimetry was performed by TEE and CMR steady state free precession sequences obtained through the aortic valvular plane. Effective AVA was calculated by the continuity equation in TTE and by cardiac catheterisation (Gorlin formula)., Results: Thirty-nine patients with aortic valve stenosis, mean age 71.7 +/- 7.6 years, with a mean AVA of 0.93 +/- 0.31 cm2 as measured by TEE, were enrolled in the study. Mean differences were: between CMR and TEE planimetry: d = 0.01 +/- 0.14 cm2, between CMR and cardiac catheterisation: d = 0.05 +/- 0.13 cm2, between CMR and TTE: d = 0.10 +/- 0.17 cm2, between TTE and TEE: d = 0.10 +/- 0.18 cm2, between TTE and cardiac catheterisation: d = 0.06 +/- 0.16 cm2, and between TEE and cardiac catheterisation: d = 0.07 +/- 0.13 cm2. Mean intraobserver and interobserver differences of CMR planimetry were d = 0.02 +/- 0.07 cm2 and d = 0.03 +/- 0.14 cm2, respectively., Conclusion: CMR planimetry of the AVA is a noninvasive and reproducible technique to evaluate stenotic aortic valves and can be used as an alternative to echocardiography or cardiac catheterisation.