Additional Procedures

Endoscopy

• Endoscopy is the visual examination of the interior of a body cavity. The fiber optic instrument used in this exam is an endoscope.

• The term endoscopy also describes surgical procedures requiring only very small incisions. Examples of these include; reconstructive knee surgery, laparoscopic cholecystectomy (gallbladder removal), bladder cancer treatment, hysterectomy, appendectomy, and lung biopsy. The procedures and instruments are named for the body parts involved. For example and arthroscope is used to perform knee surgery.

Centesis

• Centesis is a surgical puncture to remove fluid for diagnostic purposes or the remove excess fluid• Abdominocentesis is the surgical puncture of the abdominal

cavity

• Amniocentesis is a diagnostic test to evaluate fetal health

• Cardiocentesis is the puncture of a chamber of the heart for diagnosis or therapy

• Pericardiocentesis is the drawing of fluid from the pericardial sac

• Thoracentesis is the puncture of the chest wall to obtain fluid for diagnostic purposes, to drain pleural effusions, or the reexpand a collapsed lung.

Imaging Techniques

• These are used to visualize and examine internal body structures. The 3 most commonly used techniques are;

• Conventional radiography (x-ray)

• Used for hard tissues these show as white, soft tissues appear as shades of gray, and air is black

• Computed tomography (CT)

• Produce multiple cross-sectional views of the body. Hard tissues are light, and soft tissues appear as shades of gray.

• Magnetic resonance imaging (MRI)

• Used primarily to look at soft tissues. Hard tissues are dark, and soft tissues appear as shades of gray.

Contrast Medium

• A radiographic contrast medium is a substance used to make visible structures that are otherwise hard to see.

• A radiopaque contrast medium such as barium sulfate, does NOT allow the x-rays to pass through and appears white or light gray on the resulting film. Barium (Ba) is used primarily to visualize the gastrointestinal (GI) system. It is administered orally for upper GI study or rectally for a lower GI study.

• A radiolucent contrast medium, such as air or nitrogen gas, does allow the x-rays to pass through and appears black or dark gray on the resulting film

• An intravenous contrast medium is injected into the vein to make visible the flow of blood through blood vessels and organs.

Radiology

• A radiologist is a physician who specializes in diagnosing and treating diseases and disorders with x-rays and other forms of radiant energy

• Conventional radiology, also known as x-ray or radiography, creates images of hard-tissue internal structures by exposure of sensitized film to x-radiation. The resulting film is known as an x-ray or a radiograph.

• Hard tissues show as white and soft tissue show as shades of gray. Air is black.

Radiographic Positioning and Projections

Positioning & Projections

• Positioning describes the body placement and the part of the body closest to the film. For example, in a left lateral position, the left side of the body is placed nearest the film.

• The term projection describes the path that the x-ray beam follows through the body from entrance to exit.• When the name of the projection combines 2 terms into a

single word, the term listed first is the one that the x-ray penetrates first. For example, in a posteroanterior projection, the x-rays travel through the body from the posterior toward the anterior to expose the film.

Basic Radiographic Projections

• An anteroposterior projection (AP) has the patient positioned with the back parallel to the film. The x-ray beam travels from anterior to posterior.

• A posteroanterior projection (PA) has the patient positioned facing the film and parallel to it. The x-ray beam travels through the body from posterior to anterior.

• A lateral projection (Lat), also known as a side view, has the patient positioned at right angles to the film. This view is named for the side of the body nearest the film.

• An oblique projection (Obli) has the patient positioned so the body is slanted sideways to the film. This is halfway between a parallel and a right angle position. This view is named for the side of the body nearest the film. Olique means slanted sideways, and these projections are named for the portion of the body nearest the film.

Dental Radiography

• Extraoral Radiography, as used in dentistry, means that the film is placed outside of the mouth.

• A Panorex, or panoramic radiograph, shows all of the teeth and surrounding structures of the upper and lower dental arches on a single film.

• Intraoral radiography, means that the film

is placed within the mouth.

• Periapical radiographs show the entire tooth & some surrounding tissue. Used to detect abnormalities, such as an abscess, at the tip of the root.

• Bitewing radiographs, show the crowns of teeth in both arches, are used primarily to detect decay between the teeth.

Computed Tomography (CT)

• Also known as CT or computed axial tomography (CAT) uses a thin, fan-shaped x-ray beam that rotates around the patient to produce multiple cross-sectional views of the body.

• Info gathered by radiation detectors is downloaded to a computer, analyzed, and converted into gray-scale images corresponding to anatomic slices of the body. These images are viewed on a monitor or printed as hard copy (films)

Magnetic Resonance Imaging (MRI)

• MRIs are frequently used to image the brain, spine, & complex joints

• Uses a combination of radio waves and a strong magnetic field to create signals that are sent to a computer and converted into images of any plane through the body. In an MRI, hard tissues appear dark, and soft tissues are bright.

• In closed architecture MRI, also known as high-field MRI, patients may be uncomfortable because of the noise generated by the machine and the feeling of being closed in. In open architecture MRI, the design of the equipment is less confining and more comfortable for some patients.

• Because of the strong magnetic field, patients with pacemakers or other implanted electronic devices cannot be examined using these techniques.

Fluoroscopy

• Is used to visualize body parts in motion by projecting x-ray images on a luminous fluorescent screen• Cineradiography is the recording of images as they appear

in motion on a fluorescent screen.

• Fluoroscopy may also be used in conjunction with conventional x-ray techniques to capture a record of parts of the exam.

• http://www.youtube.com/watch?v=_sjYUzKnax0

Diagnostic Ultrasound

• Also known as ultrasonography, is imaging of deep body structures by recording the echoes of pulses of sound waves above the range of human hearing. The resulting record is called a sonogram

• Ultrasound is most effective for viewing solid organs not stopped by intervening bone or air.

Nuclear Medicine (NM)

• Also known as radionuclide imaging, is used for both diagnosis and treatment. Although other imaging techniques focus on the anatomic structures, NM focuses on physiological processes to determine how well body organs or systems are functioning.

• Nuclear medicine involves the use of radiopharmaceuticals that are injected or inhaled into the body and taken up by a particular organ.

• Each radiopharmaceutical contains a radionuclide tracer, also known as a radioactive tracer, which is specific to the body system being examined.

• A gamma-ray camera attached to a computer is used to generate an image showing the pattern of absorptions. It is the pattern of absorption that indicates pathology.

Nuclear Scans

• Also know as a scintigram, uses nuclear medicine technology to gather information about the structure and function of organs or systems that cannot be seen on conventional x-rays.• In a bone scan the radionuclide tracer is injected into the

bloodstream, and then the patient waits while the material travels through the body tissues. Only pathology in the bones absorbs the radionuclide, and these are visible as dark areas on the scan.

• For a thyroid scan, a radiopharmaceutical containing radioactive iodine is administered. The rate of iodine uptake by the thyroid is an indicator of thyroid function.

Single Photon Emission Computed Tomography (SPECT)

• This is a nuclear imaging technique in which pictures are taken by one to three gamma cameras after a radionuclide tracer has been injected into the blood.• In SPECT, these gamma cameras, also known as

detectors, rotate around the patient’s body, collecting data and producing images on a variety of planes.

• This technique is used to study myocardial perfusion. Perfusion is the flow of blood through the vessels of an organ.

Positron Emission Tomography (PET)

• This combines tomography with radionuclide tracers to produce enhanced images of selected body organs or areas. PET is used to determine cardiac or cerebral perfusion and for brain imaging to aid in the diagnosis of epilepsy, dementia, and recurrent brain tumors.

Radioimmunoassay

• Also known a radioassay, is a lab technique in which a radioactively labeled substance is mixed with a blood specimen.

• Assay means to determine the amount of a particular substance in a mixture. These techniques can be used to evaluate function of the pituitary and thyroid glands.

• Immunofluorescence is a method of tagging antibodies with a fluorescent dye to detect or localize antigen-antibody combinations.