Information Technology in Radiology Chapter 6

Computer-Based Imaging Techniques Computer-based imaging techniques use computers to generate pictures of internal organs of the body. A digital image is an image in a form computers can process and store, that is, in bits. Even older technologies (X-ray and ultrasound) are now computer-based.

X-rays Traditional X-rays use electromagnetic waves to produce an image on film. Digital X-rays are immediately available on screen and expose patients to less radiation. X-rays are used to image broken bones and in mammography. X-rays cannot image soft tissue.

Figure 6.1 X-ray of human chest. A traditional X-ray uses high-energy electromagnetic waves to create a picture on film. Source: jaimaa/Shutterstock.com

Ultrasound Uses sound waves and the echoes they produce to generate an image Moving image Uses no radiation

Ultrasound Used to study developing fetus and to diagnose prostate disease and gallstones Useful in diagnosing cancer in pregnant women

Figure 6.2 An ultrasound image of a 4-month-old human fetus. Source: Christophe Testi/Shutterstock.com

Ultrasound A three-dimensional ultrasonic endoscope is currently being developed for use in minimally invasive surgery. A tiny ultrasound device about the size of a silver dollar is being used to monitor fetal heart rate.

CT Scans Computerized tomography uses X-rays at many angles from which the computer creates an image. Soft tissue can be imaged. More accurate and detailed images decrease the need for exploratory surgery.

CT Scans According to a government study (2010), annual chest CTs could save lives among heavy smokers.

Figure 6.3 CT scans of human chest and abdomen. Source: Skyhawk/Shutterstock.com

Magnetic Resonance Imaging (MRI) Uses computers and a very strong magnetic field and radio waves to produce pictures

Figure 6.4 An MRI machine. Source: Levent Konuk/Shutterstock.com

MRI Images soft tissue Images brain Can find some brain abnormalities Can detect abnormal tissue Women at high risk for breast cancer benefit from yearly MRIs along with mammograms.

Functional MRI (fMRI) Can image function by measuring small metabolic changes Can locate areas of the brain affected by stroke or brain tumors Used to study conditioned response Used to study schizophrenia Used to predict dementia in patients as young as 18 who have a genetic mutation

MRI Diffusion tensor imaging (DTI)  Shows the white matter of the brain, and the connections between parts of the brain, so that these are not damaged during neuro surgery

Positron Emission Tomography (PET) Uses radioisotope technology to create an image of the brain or body in motion Used to study mental disorders, speech, Alzheimer's, moral reasoning, bipolar disorder, and cancer

Figure 6.6 A PET scan of the human brain. Source: Science Source

PET Scans Used for accurate diagnosis of breast cancer Measure an esophageal cancer patient's response to chemotherapy and radiation therapy before surgery; PET scans can detect metastases that other imaging techniques could not see Can show the functioning of the brain by measuring cerebral blood flow

SPECT Scan Single photon emission computed tomography (SPECT) scans are used in nuclear medicine Depends on gamma radiation Shows movement Can be used to study blood flow, stress fractures, infection, and tumors Used in a majority of heart imaging, and some bone scanning

Bone Density (DEXA) Scans Bone density scans or dual X-ray absorptiometry scans used to diagnose osteoporosis A special kind of low radiation X-ray that shows changes in the rays' intensity after passing through bone Shows small changes in bone density from the amount of change in the X-ray

Other Imaging Technology LUMA Cervical Imaging System is used to detect cervical cancer. Innova, a digital flat-panel biplane imaging system, can be used for many interventional, image-guided procedures.

PACS Picture archiving and communications system (PACS) is a system that transmits, stores, retrieves, and displays digital images… and communicates the information over a network. PACS is a server.

DICOM DICOM (digital imaging and communications in medicine) comprise the standard communication protocols of imaging devices.

Interventional Radiology Stereotactic radiosurgery (gamma knife surgery) is a noninvasive technique currently used to treat brain tumors with highly focused beams of radiation. The newer cyberknife can use noninvasive techniques to treat other parts of the body. Focused ultrasound is used to raise tumors to the boiling point.

Interventional Radiology Interventional radiology equipment allows nonsurgical repair of some thoracic abnormalities. The gamma knife is also being used to treat neuralgia, intractable pain, Parkinson's, and epilepsy. Radiofrequency ablation (RFA) can be used on cancerous tumors on the liver or lungs.

Interventional Radiology Interventional radiology is used in the treatment of blocked carotid arteries in patients who do not exhibit stroke symptoms and to treat and reverse male infertility with an improved embolization procedure. Lasers are being used to treat children with painful vascular malformations.

Interventional Radiology Interventional radiology is being tested as a treatment for uterine fibroids with a 92% success rate.

Figure 6.7 Patient undergoing radiosurgery. Source: Zorik Galstyan/Shutterstock.com

Dangers of Medical Radiation In the U.S., the average lifetime dose of diagnostic radiation has increased sevenfold since 1980, and more than half of all cancer patients receive radiation therapy. With the increased use of radiation have come increases in severe injury and death.

Dangers of Medical Radiation Between 2000 and 2010, there were 1,000 reports filed of injuries and deaths involving radiotherapy equipment.

Conclusion The great improvements in imaging techniques have made surgery more precise and reduced the need for exploratory surgery. The growth in interventional radiology has made it possible to do surgery without cutting.