Patient Care,

Departments & Programs,UW Hospital and Clinics

Diagnostic Radiology

Diagnostic Radiology - Departments & Programs, UW Hospital and Clinics

Diagnostic Radiology is the oldest and most widely utilized form of diagnostic imaging. This diagnostic imaging method uses X-rays to penetrate tissues of the body to study damaged or broken bones, detect foreign objects and diagnose diseases. To examine some areas of the body, it is necessary to administer a contrast agent to outline and better visualize the differences in tissues.


The Diagnostic Radiology section provides service to the OR, ED, critical care units, recovery room, inpatient units, Outpatient Treatment Center and five UW clinics. 

The staff is composed of registered technologists, imaging assistants, and clinic assistants. Health care providers have the ability to select from over 170 different general imaging procedures.


Hours of Operation


 8am-4:30pm, Monday-Friday

 CSC, 600 Highland


 Digestive Health Center (DHC)

 7:30am-5pm, Monday-Friday

 East Clinic

 8am-7pm Mondays and 8am-5pm Tuesday-Friday

 Research Park

 7:30am-5pm, Monday-Friday

 University Health Service (UHS)

 8:45am-5:15pm, Monday-Friday

 University Station

 8am-9pm, Monday-Friday and 8am-4pm, Saturday, Sunday, Holidays

 West Clinic

 8am-5pm, Monday-Friday


Are X-rays dangerous?

X-ray radiation is dangerous if you are exposed to it excessively. Modern X-ray equipment uses only a fraction of the X-ray dose that was required in the early days of radiology. Today's state of the art equipment has tightly controlled X-ray beams with significant filtration and dose control methods. As a result, scatter (stray) radiation is minimized and the parts of the body that are not being imaged receive negligible exposure.

We are all exposed to radiation every day, primarily from the sun but also from rocks and soil. This is called background radiation. Radiation from medical X-rays accounts for about 10% of the total radiation that we will receive in a lifetime. The amount of radiation that you receive from a chest X-ray is about one tenth of the dose that you would receive from background radiation in one year.

How are X-rays created?

X-rays are created by the act of electrons bombarding a metal target inside an X-ray tube. To create this stream of electrons, a generator takes the regular alternating current (AC) electricity and transforms it into very high voltage. When the high voltage is applied to the X-ray tube, a tight beam of electrons pass out of a small wire (called the cathode) and strikes the metal disk (called the anode). This action and the unique atomic structure of the metal disk create X-rays. As the X-rays leave the tube, they are filtered and focused. They pass through the body in a straight line and are recorded onto an image receptor.

How does a patient get the results of an X-ray procedure?

A radiologist will analyze and compare the images to any similar procedures that the patient might have had. The radiologist will send a formal report to the patient's primary care or referring physician, who will inform the patient of the test results. New technology also allows for distribution of diagnostic reports and visualization of the images over the Internet.

What are contrast agents and why are they used?

A contrast agent is a solution that can be used to enhance the density of various structures in the body. When combined with x-rays, it can provide valuable information about various diseases in the body. Contrast agents can be given orally, intravenously or by other routes depending on the region that is being investigated. 

What does a patient experience during an X-ray procedure?

You cannot feel X-rays; therefore, the imaging itself is painless. For some procedures, though, the patient may be required to lie down on a hard surface that may feel cold. The patient may be asked to hold an uncomfortable position for a few minutes or to hold their breath. It is extremely important that the patient does not move during the exposure, as any motion could cause blurring of the image, resulting in the necessity to repeat the image.

What is Computerized Radiography (CR)?

Computerized Radiography uses a normal X-ray machine and an image receptor (cassette) to record an image. But instead of recording the image on a piece of X-ray film, the image is recorded on a phosphor plate which has been placed within the cassette. The plate is processed through a machine that reads and converts the image to a digital format. The final image can be displayed on a monitor, burned on a CD or processed as a "hard copy" image.

The benefits of CR imaging include:

What is Digital Radiology (DR)?

Digital Radiography (DR) is very similar to Computed Radiography (CR). The main difference is that with DR, the image detectors are located inside the X-ray machine. The detectors capture procedure information immediately after the exposure has been made, thus eliminating the need for a cassette, imaging plate and plate processor. As with CR, digital images can be displayed on a monitor, stored in a picture archive and communication system (PACS), or printed as "hard copies."

What is dual energy imaging?

Dual energy imaging is the process by which two posterior-anterior (PA) images are obtained of the chest. These two images are separated by approximately 200 milliseconds and are acquired by using two different energy ranges for the exposure. The two PA images provide the radiologist with a standard PA chest image, a soft-tissue image of the chest (bones removed) and an image of the skeletal system (bone image).

The advantage of this method of chest imaging is that the radiologist can visualize the area of the chest that would normally be obstructed by bone. The radiologist can also study the bones of the chest and determine if there are any abnormal calcifications present.

What is fluoroscopy?

The principles of fluoroscopy are basically the same as with conventional X-ray, only with fluoroscopy you are looking at a real time moving X-ray picture on a TV monitor. Fluoroscopes consist of an X-ray tube and a fluorescent screen. When X-rays hit the screen, an image is formed. The image is then transmitted to the television monitor by a camera. Fluoroscopy is frequently used to observe the digestive tract and for guiding tubes or spinal injections. 

What makes structures on the x-ray image appear white, black or gray?

The different types (density) of tissues that the X-rays pass through on their way through to the image receptor determines the various shades of white, black and gray on the radiograph. Calcium in the bones absorbs (blocks) the passage of X-rays, so bones appear white on the image. Air in the lungs, on the other hand, absorbs very little of the X-ray beam, so they take on a black appearance. Other soft issues of the body - such as the liver, heart and muscles - are of intermediate density. This explains why on a chest image the heart and vessels are contrasted against the air in the lungs and clearly seen.


Special Views

Standard Operating Guidelines (SOGs)



DR: IVU Setup and Procedure



Breast Imaging

Computed Tomography (CT)

Image Management

Interventional Radiology

Magnetic Resonance Imaging (MRI)