Peripheral arterial disease: the evolving role of non-invasive imaging

Abstract

Peripheral arterial disease is usually secondary to stenotic or occlusive atherosclerosis and is both common and increasing in western society. The majority of symptomatic patients have intermittent claudication and only a minority (<2% and typically those with diabetes mellitus or renal failure) progress to critical limb ischaemia, heralded by the onset of rest pain and/or tissue loss. Imaging is largely reserved for patients with disabling symptoms in whom revascularisation is planned. In these patients, accurate depiction of the vascular anatomy is critical for clinical decision making as the distribution and severity of disease are key factors determining whether revascularisation should be by endovascular techniques or open surgery. Driven by advances in technology, non-invasive vascular imaging has recently undergone significant refinement and has replaced conventional digital subtraction angiography for many clinical indications. In this review, the relative merits and limitations of duplex ultrasound, CT angiography, and magnetic resonance angiography are discussed, emerging imaging techniques are described, and complications relating to the use of intravascular contrast agents are highlighted.

Interventions to reduce major vascular complications of TAVR

“…This carries some risk for contrast-induced nephropathy. In a recent study of patients undergoing MDCT, the incidence of contrast-induced nephropathy was 0.6% in those with a glomerular filtration rate of 40-60 ml/min and 7.8% in those with a glomerular filtration rate <30 ml/min [19]. Therefore, MDCT is often not performed in patients with severe renal insufficiency [9].…”

Re-assessing the enhanced permeability and retention effect in peripheral arterial disease using radiolabeled long circulating nanoparticles

“…Duplex Doppler ultrasound imaging can evaluate the location and extent of the disease and arterial hemodynamics, yet the scans are time-consuming and calcification stenosis can limit the evaluation [12]. Besides Doppler imaging, magnetic resonance angiography (MRA) and computed tomography angiography (CTA) are two additional modalities utilized for noninvasive imaging of PAD [13]. MRA can effectively assess the location and degree of stenosis; yet is limited by high cost, motion artifacts, and decreased signal caused by metal clips or stents.…”

Patient Perception of Lower Limb Non-Contrast Magnetic Resonance Angiography and Digital Subtraction Angiography in Diabetic Patients with Peripheral Arterial Disease

“…Gadolinium administration has also been correlated with a high T1 signal intensity in the dentate nucleus and globus pallidus [12]. Contrast-enhanced computed tomography angiography (CTA) is rapidly performed and non-invasive, but involves potentially nephrotoxic iodine-based contrast and radiation exposure, and assessment of below-theknee vessels is challenging in the presence of heavy calcification and individual variability in the timing of peak arterial opacification [4,13,14]. Ultrasonography is safe and non-invasive, but also operator dependent and relies upon favorable acoustic windows [4].…”

“…Contrast-enhanced computed tomography angiography (CTA) is rapidly performed and non-invasive, but involves potentially nephrotoxic iodine-based contrast and radiation exposure, and assessment of below-theknee vessels is challenging in the presence of heavy calcification and individual variability in the timing of peak arterial opacification [4,13,14]. Ultrasonography is safe and non-invasive, but also operator dependent and relies upon favorable acoustic windows [4]. Digital subtraction angiography (DSA) remains the gold standard for PAD imaging, and is often required for interventions such as angioplasty or stent insertion.…”

“…There are several imaging options in clinical practice for PAD [4]. Gadolinium-enhanced magnetic resonance angiography (MRA) is a non-invasive modality that can reliably assess PAD [5,6].…”