Technology Will Save Our Minds and Bodies

By: Lisa-Marie De Buono

Medical Imaging: Illuminating the Body

The History of Medical Imaging

Up until fifty years ago, X-ray was the only non surgical means to extract information within a living body (Hoehn & Marieb, 2010).

In the 1950’s, nuclear medicine (radioisotopes to scan the body) and ultrasound technology (which incorporates sound waves) was created (Hoehn & Marieb, 2010) .

The 1970’s brought CT, PET and MRI scans. This more modern technology reveals structure and molecules with the body (Hoehn & Marieb, 2010).

The X-Ray

Is a negative image of internal structures. Dense structures in the body absorb the rays the most and appear as light areas (Hoehn & Marieb, 2010).

Hollow air containing organs and fat show up on an X-ray as a dark area (Hoehn & Marieb, 2010).

Pros: Visualizes hard, bony structures and locates abnormally dense structures (ex. tumours and tuberculosis nodules) in the lungs, is simple , has excellent bone contrast and is inexpensive (Queens University, 2008).

Cons: Radiation from X-ray can be harmful to patient, loss of shape and depth of objects, poor soft tissue contrast and delay between shots and seeing films (Queens University, 2008).

Nuclear Medicine Imaging Radioactive materials (radiopharmaceuticals) which are tagged

with radioactive material to treat or diagnose disease are injected into patients. The radioactive materials emit gamma rays which can be detected on a special camera, creating a nuclear image (St. Michael’s Hospital, 2013).

Pros: 100 different nuclear medicines and tests available, can measure the degree of organ function and is often able to detect disease for early diagnosis (St. Michael’s Hospital, 2013).

Cons: Radiation can potentially be harmful for the patient (St. Michael’s Hospital, 2013).

Ultrasound Imaging

Uses high frequency sound waves that pass through the body. Sound waves are reflected or bounced off internal organs and tissues. The waves are then recorded and displayed via computer. Can be used to view the abdomen, heart, blood flow, pregnancy, muscles, tendons, and soft tissue (ACRIN, 2013).

Pros: Non-invasive, uses no radiation, guides minimally invasive procedures using real time imaging (ex. Needle biopsies), is easy to use and widely available (ACRIN, 2013).

Cons: No known risks (ACRIN, 2013).

Computed Tomography (CT) A more refined version of X-ray technology. Patient is moved

slowly through a CT machine. It’s X-ray tube rotates around the body and sends beams from all directions. The computer then translates this information into a detailed cross sectional picture of each body region scanned (Hoehn & Marieb, 2010).

Pros: Able to help diagnose most problems that affect the brain and abdomen, has almost eliminated exploratory surgery , non-invasive, quick, shows bone changes better than any other scanning equipment, provides images of soft tissue and blood vessels (Radiology Info, 2013) .

Cons: Radiation can be harmful (Radiology Info, 2013).

Positron Emission Tomography(PET )

A more advanced nuclear medicine imaging, PET observes metabolic processes. Patient is given an injection of radioisotopes tagged to biological molecules and is then positioned in the scanner. Gamma rays are produced in the brain and the computer is then able to generate a live action picture of the brains biochemical activity. PET can provide insight into brain activity in those with mental illness, stroke, Alzheimer's disease and epilepsy (Hoehn & Marieb, 2010)..

Pros: insight into the brains of those diagnosed with diseases which affect the brain, is able to also detect changes in the brains of those who are not yet diagnosed ( identifies area of decreased metabolism in crucial memory- suggesting eventual Alzheimer's), and determines which areas of the healthy brain are most active (Hoehn & Marieb, 2010).

Cons: Radiation may affect patient (Hoehn & Marieb, 2010).

Magnetic Resonance Imaging(MRI )

Produces high contrast images of our soft tissues. MRI maps the body's content of hydrogen. The patient lies in a chamber within a huge magnet, energy released by the hydrogen molecules and is translated into a visual image (Hoehn & Marieb, 2010).

Pros: Easily captures views of the skull and vertebral column, great at detecting tumours and degenerative disease (Hoehn & Marieb, 2010).

Cons: Radiation may cause harm to patients (Hoehn & Marieb, 2010).

Upcoming!

Watch for Magnetic Resonance Spectroscopy (MRS) to come to a

hospital near you! This technology reveals how diseases changes the

chemistry of our body.

Conclusion

Medical imaging is changing the way we think, learn and discover disease

and illness. Most importantly, medical imaging is saving and

improving lives each day.

References American College of Radiology Imaging Network.(2013). About

Ultrasound Scans. Retrieved from http://www.acrin.org/PATIENTS/ABOUTIMAGINGEXAMSANDAGENTS/ABOUTULTRASOUNDSCANS.aspx

Hoehn, K. & Marieb, E. Human Anatomy & Physiology (8th Ed.). (2010). San Francisco: Pearson

Queen’s University.(2008). X-ray Imaging. Retrieved from http://research.cs.queensu.ca/home/comp230/Lectures/X-ray/X-ray.pdf

Radiology Info.(2013). Pros, Cons and Side Effects of a CT Scan What are the Benefits of a CT Scan? Retrieved from http://www.radiology-info.org/computed-tomography/pros-cons-side-effects-ct-scan-what-are-benefits-ct--scan.html

St. Michaels.(2013). Medical Imagining. Retrieved from http://www.stmichaelshospital.com/programs/imaging/nuclear/