Non-gadolinium enhanced MRA of the lower extremities
|Principal Investigator: VivianLee|
|Keywords: Claudication , Peripheral Artery Disease , Magnetic Resonance Imaging , Healthy Volunteer , Gadolinium Contrast , Muscle Imaging , Lower Extremity Pain||Department: University of Utah|
|IRB Number: 00050494||Co Investigator:|
|Specialty: Vascular Surgery, Radiology|
|Sub Specialties: Magnetic Resonance Imaging – MRI|
To systematically develop, test, and refine peripheral vascular ECG-gated fast spin echo (FSE) MRI for the accurate diagnosis of PAD without Gd contrast.
To test prospectively the accuracy of FSE in 200 PAD patients, compared with bolus-chase and time-resolved Gd-MRA and, in a subset, intraoperative x-ray angiography as reference techniques. Additionally, as a substudy of this project, we will compare our FSE approach with alternative non-contrast-enhanced MRI methods such as time-of-flight and steady-state gradient echo imaging.
The overarching goals of our research are to develop and validate a peripheral MRA technique that accurately depicts anatomy and disease without exposing patients to exogenous contrast material and its associated risks.
To develop, test, and refine advanced muscle MR imaging techniques, including BOLD, ASL and both myoglobin and phosphorus spectroscopy.
Hypothesis: Using advanced MR techniques, we can examine the extent of oxygenation, energetics, and perfusion abnormality present in lower extremity musculature in patients with PAD.
To develop techniques to utilize these non-gadolinium techniques to evaluate extremity vascularity in patients with frostbite before and after treatment with tPA or other medications.
The intended gender distribution of the subjects will be approximately equal. There will be no gender based enrollment restrictions. The age range of the subjects is 18-95. No children will be recruited, as PAD is a disease of adulthood, with increased prevalence in the elderly population. There are no enrollment restrictions based upon race or ethnic origin. Patients with stents may be included.
Patients with known or suspected PAD will be recruited. In the initial sequence optimization stage, healthy volunteers will also be recruited for MRA examination and/or muscle physiology measurements.
Patients with moderate to end stage renal disease (estimated GFR < 30 ml/min/1.73m2). These patients will not be recruited as they will be unlikely to undergo routine contrast enhanced MRA due to the risk of developing Nephrogenic Systemic Fibrosis.
Pregnant patients. Gadolinium chelates are a FDA Category C drug, and therefore should be avoided in pregnancy.
Claustrophobic healthy volunteers or any subject who is unable to lie flat for 60 minutes.
Dialysis dependence or eGFR (MDRD calculator) based on serum Cr within 1 month of imaging < 15ml/min/1.73m2
eGFR < 60ml/min/1.72m2 and coexisting history of pro inflammatory conditions such as recent surgery, sepsis or major infection, arterial or venous thrombosis.
Any history of nephrogenic systemic fibrosis
Unable/ unwilling to give informed consent
Medical contra-indications to MRI: e.g. pacemakers, implanted defibrillators, cochlear implants, aneurysm clips, and prior/ current metal workers. Patients will be screened with a safety questionnaire.
Clinically unstable patients
Patients with newly placed stents will be excluded until 8 weeks post placement