DIAGNOSTIC IMAGING SCANS
MRIs are used to scan and examine one part of your body at a time. The scan can focus on many parts of the anatomy. There is even a form of MRI that can look at blood vessels and the flow of the blood as it goes through them—called Magnetic Resonance Angiography (MRA). These kinds of scans can help to find arterial and vein problems, such as a blocked vessel, torn vessel lining or aneurysm. They can help to find the most malignancies and neurological diseases of the brain and spine, such as: brain tumors, Alzheimer’s disease, cervical cancer, and multiple sclerosis (MS). For more, click here.
CT (Computed Tomography) scanning—or CAT (Computer Axial Tomography) scanning-is a noninvasive medical imaging method that uses tomography to diagnose and to treat medical conditions. It is 3-D images complied from many pictures of the same area taken from different angles. CT scans provide greater clarity and detail of internal organs, bones, soft tissues, and blood vessels. Additionally, though they do involve x-rays, the diagnostic benefits generally outweigh the risks of x-ray radiation exposure. With CT scans, radiologists can more easily diagnose diseases such as cancers, cardiovascular disease, infectious disease, appendicitis, trauma, and musculoskeletal disorders. It is also invaluable in diagnosing and treating spinal problems and injuries to the hands, feet, and other skeletal structures because of CT image’s ability to show even the very small bones as well as surrounding tissues such as muscle and blood vessels. For more, click here.
Differences in CT and MRI
First, CT uses x-rays to detect and record the radiation absorbed by difference tissues. Then, it sends the data to a computer to transform into images. On the other hand, MRI does not use x-rays, but employs a powerful magnetic field. This field will monitor the nuclei of hydrogen atoms in water (the most abundant element in the body). Then, when subjected to MRI’s magnetic field, the hydrogen protons are knocked out of alignment and emit a radiofrequency signal that is detected by the MRI machine and processed into images.
Second, CT scans highlight solid structures like calcium deposits or kidney stones, while showing little differentiation in soft tissues. MRI scans emphasize detailed tissue structures with their differences in water content.
A positron emission tomography (PET) scan is a molecular imaging procedure that reveals unique information about how an organ or tissues are functioning. It is a painless and non-invasive procedure that uses radiation, or nuclear medicine imaging, to produce 3-D color images of the functional processes within the human body. In most cases, PET scans are taken to assess cancers, neurological (brain) diseases and cardiovascular (heart-related) diseases. A PET scan eliminates the need for surgical biopsy and can detect whether diseases are benign or malignant. It is a great tool that assists physicians in evaluating treatment options and in assessing the process of those treatments.
Though with PET scans, there are possible risks derived from the radioactive substances used, the amount of radiation exposed is too low to actually affect the normal functioning of a patient’s body. For more, click here.
A mammogram uses a technique called mammography to visualize normal and abnormal structures within the breasts. This is a low-dose x-ray test that generates images of the inner breast tissue on film. Therefore, a mammography identifies cysts, calcifications, and tumors within the breast. Currently, it is the most efficient screening method that detects early signs of breast cancer. The American Cancer Society suggests that women take her first baseline mammogram in the ages between 35 and 40. After the age of 40, experts recommend a yearly mammogram. For more, click here.
Ultrasound scan, also called sonogram, diagnostic sonography, and ultrasonography, is a machine that utilizes high frequency sound waves to generate an image of the inside of the body. Often used to detect problems in the liver, kidney, abdomen, or the heart, it is also helpful to surgeons carrying out biopsies. Ultrasound is noninvasive—not penetrating the skin or body openings—and diagnostic—determines what disease is present. As ultrasound images are captured in real-time, they can display the internal organ’s structure and movement in the body, as well as the blood flowing through blood vessels.
There are many types of ultrasound imaging: the conventional ultrasound, the three-dimensional ultrasound, the four-dimensional ultrasound, and the Doppler ultrasound.
Overall, ultrasound is the preferred imaging modality for diagnosing and monitoring pregnant women with their unborn babies. For more, click here.
Like visible light, an x-ray is a form of electromagnetic radiation. The x-ray machine sends individual x-ray particles—photons—that pass through the body. Then, a computer of special film records the images generated. Bones and parts of the body with dense structures will block most of the x-ray particles. Consequently, they will appear white on the images. Note that metal and contrast materials will also appear white on an x-ray image. Structures with air will be black. Muscle, fat, and fluid on the other hand will appear as shades of gray.
Per radiograph, a small fraction of the x-rays passes through the body. The tissues in the body absorb the remaining photons. Then, the energy of the absorbed photons can ionize (break apart) compounds, causing cell damage. At most times, this cell damage will be soon repaired. For more, click here.