Epidural fibrosis is scar tissue that forms in the epidural space around the spinal nerves. It most commonly develops after spine surgery, especially after procedures that expose the nerve roots. Clinicians use the term to describe a healing response that may or may not be related to ongoing symptoms. It is most often discussed in the context of persistent leg or arm pain after surgery.

Intravascular Ultrasound is a catheter-based imaging test done from inside a blood vessel. It uses ultrasound (sound waves) to create cross-sectional pictures of the vessel wall and lumen (the open channel where blood flows). It is most commonly used during cardiac catheterization, especially when treating coronary artery disease. It can also be used in selected peripheral artery and venous procedures.

Spinal arachnoiditis is inflammation and scarring of the arachnoid, one of the membranes that surrounds the spinal cord and nerve roots. It can cause nerve roots to become irritated, stuck together, or tethered. It is most often discussed in the context of chronic back or leg pain and neurologic symptoms after certain spine conditions or interventions. The term is commonly used in radiology reports (MRI) and in neurosurgery, orthopedic spine, pain medicine, and rehabilitation clinics.

iFR is a pressure-based measurement used to assess blood flow limitation in a coronary artery narrowing. It stands for *instantaneous wave-free ratio*. It is most commonly measured during coronary angiography in a cardiac catheterization laboratory. It helps clinicians decide whether a coronary narrowing is likely to benefit from procedures like stenting.

An **Aortic Aneurysm** is an abnormal widening (dilation) of the aorta, the body’s largest artery. It means a section of the aortic wall has weakened and expanded beyond its usual size. Aortic aneurysms can develop in the chest (thoracic aorta) or abdomen (abdominal aorta). Clinicians commonly use the term when discussing imaging findings, rupture risk, and treatment planning.

Retrolisthesis is a spinal alignment finding where one vertebra shifts backward relative to the vertebra below it. It is most often described on X-ray, CT, or MRI reports of the neck (cervical spine) or low back (lumbar spine). Clinicians use the term to document anatomy, communicate severity, and guide further evaluation. Retrolisthesis is a descriptive diagnosis, not a treatment.

A Venous Ulcer is an open sore on the lower leg or ankle caused by long-standing problems with blood flow in the leg veins. It is a type of chronic wound that tends to heal slowly and can recur. It is most often discussed in vascular medicine, cardiology-related vascular care, wound care, and primary care. It commonly appears near the ankle and is linked to chronic venous insufficiency (poor venous return).

Isthmic spondylolisthesis is a spinal condition where one vertebra slips forward relative to the vertebra below it. It most often relates to a defect or stress fracture in the pars interarticularis, a small bony bridge in the back part of the vertebra. It is commonly discussed in spine clinics when evaluating low back pain, leg pain (sciatica), or spinal alignment on imaging. It is also a key diagnosis in sports medicine and adolescent/young adult spine care, because pars injuries can develop with repeated extension and rotation.

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Chronic Venous Insufficiency is a long-term problem where veins in the legs have difficulty returning blood back to the heart. It commonly happens when vein valves weaken or when veins become blocked or damaged. The result is blood pooling in the lower legs, which can cause swelling, skin changes, and sometimes ulcers. The term is commonly used in vascular medicine, cardiology-related vascular care, and general clinical practice when evaluating leg symptoms.