Pulmonary MR Angiography and Lower Extremity MR Venous Imaging Using a Single Dose of Gadofosveset (Ablavar)

Specific Aim 1: To assess first-pass SNR and CNR of pulmonary MR angiography performed with 0.03 mmol/Kg of intravenous gadofosveset trisodium.

Hypothesis: Use of 0.03 mmol/Kg of gadofosveset trisodium in gradient recalled echo pulmonary MR angiography will provide a pulmonary artery SNR and CNR equal to or better than the SNR and CNR obtained using the same MR technique with 0.2 mmol/Kg of a conventional contrast agent (gadopentetate dimeglumine) and equal to or better than 0.1 mmol/Kg of intravenous gadobenate dimeglumine. Data will be compared to SNR and CNR of pulmonary MR angiogram images obtained at Washington University as part of the PIOPED III study.

Specific Aim 2: To assess SNR and CNR of breath-hold pulmonary MR imaging obtained immediately after the original first-pass breath-hold pulmonary MR angiography.

Hypothesis: SNR and CNR of pulmonary MR angiography performed immediately after first-pass breath-hold pulmonary MR angiography will be at least equal to the SNR and CNR obtained using the same MR technique with 0.2 mmol/Kg of a conventional contrast agent (gadopentetate dimeglumine) and at least equal to 0.1 mmol/Kg of intravenous gadobenate dimeglumine.

Specific Aim 3: To assess SNR and CNR of lower extremity MR venogram (MRV) performed immediately after the two pulmonary MR angiograms, described above.