In physics, attenuation (in some contexts also called extinction) is the gradual loss in intensity of any kind of flux through a medium. For instance, sunlight is attenuated by dark glasses, X-rays are attenuated by lead, and light and sound are attenuated by water.n engineering, attenuation is usually measured in units of decibels per unit length of medium (dB/cm, dB/km, etc.) and is represented by the attenuation coefficient of the medium in question.
PET Scan (Skull to Mid-Thigh) Cost and Procedure Information. Positron Emission Tomography, also called a PET scan, is a diagnostic examination that involves the acquisition of physiologic images based on the detection of radiation from the emission of positrons. Positrons are tiny particles emitted from a radioactive substance administered to the patient.
The process of bone graft incorporation in a spinal fusion model is similar to the bone healing process that occurs in fractured long bones. Fracture healing restores the tissue to its original physical and mechanical properties and is influenced by a variety of systemic and local factors. Healing occurs in three distinct but overlapping stages: 1) the early inflammatory stage; 2) the repair stage; and 3) the late remodeling stage. In the inflammatory stage, a hematoma develops within the fracture site during the first few hours and days.