What’s The Difference?

By: Porter Regional Hospital Last Updated: March 23, 2010

From the Winter 2010 StayHealthy publication

At CT (Computerized Axial Tomography) is a specialized type of x-ray that generates images of the body, particularly bony and calcium based structures. ct-mriDuring the CT scan, patients lie on a table that slides into a scanning machine. An x-ray tube rotates around the body creating crosssectional images like slices of the inside of the body. Porter’s 64- slice CT scanner delivers images with very high resolution. The slices can be studied individually or placed together to form a three-dimensional model of the area being studied.

“Unlike a regular x-ray, a CT provides greater clarity and reveals more details of internal organs, bone, soft tissue and blood vessels,” explained radiologist Amjad Alkadri, MD. “CT scans have significantly improved our ability to diagnose problems such as cancers, cardiovascular disease, infectious disease, trauma, and musculoskeletal disorders.”

Unlike a CT, an MRI (Magnetic Resonance Imaging) is most commonly used to examine the central nervous system and to identify tumors, strokes, degenerative diseases, and other abnormalities in organs and soft tissue. When a patient lies inside the MRI machine, which is a large, tube-shaped magnet, the magnetic field temporarily aligns the water molecules inside the body. Radio waves then cause the aligned molecules to produce faint signals used to create cross-sectional images. These images can be combined to produce 3-D images able to be viewed from many different angles.

When MRI technology first appeared, it was mainly used to image the brain and spinal column. “Today, we are seeing more and better uses for MRI,” Dr. Alkadri shared. “Now we can non-invasively look at a host of body parts and diagnose conditions such as coronary artery disease, vascular disease, valve disease and more. And, with Porter’s recent installation of the Panorama MR, which offers wide-open patient space and produces superb images, people no longer have to travel outside of Porter County to have an open MR exam.”

A common question patients often have is “Which is better: CT or an MRI?” In fact, neither one is better than the other – both are exceptional diagnostic tools used to gather different types of information.

CT scans help:

  • Diagnose muscle and bone disorders, such as bone tumors and fractures.
  • Pinpoint the location of a tumor, infection or blood clot.
  • Guide procedures such as surgery, biopsy and radiation therapy.
  • Detect and monitor diseases such as cancer or heart disease.
  • Detect internal injuries and internal bleeding.

An MRI can help:

  • Detect/diagnose abnormalities of the brain and spinal cord.
  • Identify important language and movement control areas in the brain in people who are being considered for brain surgery.
  • Better visualize cardiac anatomy and function.
  • Check for tumors or other abnormalities of internal organs.
  • Evaluate bone and joint disorders, abnormalities or infections.
  • Detect breast cancer in women with dense breast tissue or who are at high risk.