BOLD MRI as a Surrogate of Improved Muscle Oxygenation Following Endovascular Therapy for the Treatment of CLI

This study is a prospective single arm, open label registry to evaluate the feasibility of
blood oxygen level dependent (BOLD) magnetic resonance imaging for the assessment of a
potentially new functional surrogate of altered lower limb skeletal muscle oxygenation after
a successful percutaneous endovascular intervention. Baseline MRI assessment using the BOLD
technique will be performed on qualified subjects prior to undergoing a standard of care
endovascular therapy. Post-procedure BOLD-MRI assessment will also be performed at 30 days
and either 90 or 180 days post-procedure. Post-MR image acquisition processing and analysis
will be performed, using pre-determined algorithms, by a core laboratory.

Inclusion Criteria:

- Age > 18 and < 90 years

- Subject has been informed of the nature of the study and agreed to participate and has
signed an IRB approved consent form

- Subject understands the duration of the study and its follow-up visit requirements and
agrees to comply

- Subject has documented chronic limb ischemia in the target limb with Rutherford
Category 2-5 and pulse plethysmography (PPG), pulse volume recording (PVRs), TcPO2,
ABIs or toe pressures and symptoms that conform to the diagnosis of life-style
limiting claudication or critical limb ischemia

Exclusion Criteria:

- Adult subjects who lack the capacity to consent for themselves

- Women who are pregnant or wish to become pregnant during the course of the study.
(Women of child-bearing potential must undergo pregnancy testing at the time of
enrollment, and be counseled in appropriate measures to avoid becoming pregnant for
the duration of the study)

- Subjects with contraindications to MR imaging procedures (including the administration
of gadolinium based contrast agents)

- Subjects suspected to be unable to withstand the reactive hyperemia protocol