Approximately 8 to 12 million people in the United States alone are suffering from peripheral arterial disease (PAD), a common vascular problem that is caused by narrowing of the arteries as a result of plaque buildup. The plaque accumulation leads to an insufficient blood flow to the body’s extremities and increases a person’s risk for heart attack and stroke by up to six times. PAD is also one of the most serious complications of diabetes.
Now, a team from Columbia University is developing a novel technology that could improve diagnosis of this crippling disease and make it easier to monitor patients. This dynamic optical tomographic imaging system uses near-infrared light to map the concentration of hemoglobin in the body’s tissue and reveal how well blood is perfusing patients’ hands and feet.
The team state that their novel vascular optical tomographic imaging (VOTI) system will revolutionize the way the medical community diagnoses and monitors peripheral artery disease. The group have been working on this research for the last three years, testing a prototype system in clinical pilot studies. The opensource study is published in the European Journal of Vascular and Endovascular Surgery.
The researchers explain that as most patients are asymptomatic and there is no single reliable screening method, PAD is considerably under-diagnosed. Most of the undiagnosed and untreated patients are diabetics who commonly suffer from peripheral neuropathy and therefore do not sense and report symptoms, such as pain while walking, that are early signs of the disease. In fact, more than 60% (~75,000 per year) of all lower extremity amputations in the United States are performed in diabetic patients with PAD. With the number of diabetic patients expected to triple and reach almost 100 million by 2050, the problems related to undiagnosed PAD will only rise in the years to come.
The team hopes to remedy that with the VOTI system, which relies on near-infrared light that is shone onto different locations on a patient’s foot. Transmitted light intensities are then used to generate spatially resolved maps of oxy- and deoxy-hemoglobin, the two main components of blood.
The team state that they have successfully used the VOTI to detect PAD in the lower extremities. Unlike other methods, the VOTI technology can provide maps of oxy-, deoxy-, and total hemoglobin concentration throughout the patient’s foot and identify problematic regions that require intervention.
Source: Columbia University