Radiography is a type of diagnostic medical imaging. The different modalities are used to visualize almost the entire body in an effort to diagnose disease processes. Because different tissues react differently to each imaging modality, a specific modality may be better suited for the diagnosis of a specific disease, or a combination of exams may be necessary.
X-Ray
X-rays, or radiographs, have many uses. They are ideal for imaging the bones in search of breaks. A bone survey is a series of x-rays taken to determine whether cancer has metastasized to the bones. KUB is an x-ray of the kidneys, ureters and bladder. It is used in conjunction with contrast to search for stones and other blockages. Chest x-rays are ideal for evaluating the lungs for the presence of pneumonia.
Fluoroscopy
Fluoroscopy is x-ray using real-time imaging. It can be used in conjunction with barium contrast to find gastrointestinal abnormalities such as bowel intussusception. Intravenous contrast can be used to visualize venous or arterial stenosis. Fluoroscopy is the preferred imaging modality by some radiologists for surgical procedures. Medical equipment, such as guide wires, can be easily seen and properly placed using fluoroscopy.
Computed Tomography
Computed tomography (CT) uses special x-ray equipment. Special computer software is used to process the images. They can be manipulated for enhanced visualization and varied orientation. CT scans can also be used to produce three-dimensional reconstructions that are helpful in the diagnosis of certain pathologies. While computed tomography uses x-rays, it produces much more detailed imaging than radiographs.
Nuclear Medicine
Nuclear medicine uses radiation differently than the other imaging modalities. Radioactive substances are injected into the patient and allowed to function within the body. A special camera is used to acquire images of the radiation given off by these substances. This process allows the physician to assess whether an organ is properly functioning. Nuclear medicine is the only radiographic imaging modality that can examine how well an organ functions.
Other Imaging Modalities
Radiographic exams may be complimented with ultrasound or magnetic resonance imaging (MRI). Because injuries and disease processes may affect several types of tissue, two imaging modalities may be required. For example, an x-ray may be taken of an injured arm to search for a fracture. If a tendon or ligament tear is suspected in addition to the break, MRI will also be used. CT is used to assess abdominal pain and can be used to find masses in the liver and gallstones in the gallbladder. Ultrasound is done in addition to the CT to evaluate the common bile duct, which may also have stones.
Tags: imaging modality, also used, conjunction with, disease processes, imaging modalities
