Fluoroscopy has been a very effective tool in interventional pain management procedures. Not only does the x-ray image help one identify the proper target for the needle placement but also helps to determine the proper spread of the injectate as well as identify inadvertent intravascular placement of a needle and thus the injectate. Portable fluoroscopy units (also called the C-arm) have helped improve the effectiveness as well as safety of interventional pain management procedures. However, at the same time, it has also increased radiation-related injuries to physicians and their staff as well as patients. Whereas proper use of fluoroscopy can help safe placement of the needle and the injectate, excessive and improper use of fluoroscopy can lead to radiation-induced injuries. Physicians who performed radiography and fluoroscopy in the first half of the 20th century had higher rates of cancer-related deaths than any other physicians. The US Food and Drug Administration (FDA) issued an advisory in 1994 suggesting that the key to preventing such unfortunate mishaps may be physician education, training, and credentialing in the safe operation of fluoroscopic equipment. Proper understanding of the radiation dosage, scatter pattern of x-rays while using the fluoroscopy machine, understanding the fluoroscopy machine and using it properly would lead to improved patient care and minimal tissue trauma to the patient, physician, and ancillary staff from radiation.
Several issues need to be considered when using x-rays on a human body.
The human body does absorb radiation.
The human tissue can be damaged by radiation.
Larger human beings require higher radiation exposure for proper imaging.
Lateral mass of the human body requires more radiation than anteroposterior mass.
Larger individuals require longer needles but provide shorter space between the body and the image intensifier, thereby making the placement of the needle more difficult.
Placement of the image intensifier can influence the amount of radiation scatter around the patient. Usually the scatter is less if the image intensifier is closer to the patient (Figure 4-1).
The larger circular part of the C-arm is called the image intensifier (I-I) and the smaller part is the actual x-ray tube. Closer placement of the image intensifier helps reduce the scatter of radiation.
BASIC CONCERNS AND CONTRAINDICATIONS
Some concerns regarding the proper use of fluoroscopy units are inadequately trained radiology technicians, physicians who are untrained in the use of fluoroscopy, improperly maintained machines, and inadequate space.
Use of fluoroscopy is unadvisable during pregnancy as it may lead to fetal injury from radiation, especially during the first trimester.
Effects of radiation on different tissues are variable:
Radiation is carcinogenic.
Effects are permanent for the most part.
Total dosage (absorption) is cumulative over lifetime.
Any exposed part ...