Medical Imaging

The Various Types of Medical Scanners

Medical scanners date back to the late 1940s, when an Englishman named John Wild used the first ultrasound to evaluate bowel tissue thickness. The first commercial medical scanner was released in 1963 as a hand-held device, which began the history of the use of ultrasound scanners in the medical field. Since that time, technological advances have opened the door to highly intricate scanning devices, providing radiologists and physicians with powerful imaging results for diagnosing disorders and disease. There are several types of medical scanners used today for imaging with each type offering its own benefits. senso duo

Computed Tomography Scanners

Computed Tomography (CT) scanners are the new and improved versions of the prior Computed Anial Tomography (CAT) scanners. Because CAT scanners were expensive, time consuming and cumbersome, CT scanners were developed. These devices can provide quick images of the bone, brain, lung and other areas of the body, resulting in a three dimensional image. The CT scanner works by encircling the patient with radiation detectors, while an x-ray beam rotates and passes through the patient. The multitudes of transmitted beams are then projected into a high-resolution image. CT scans usually take less than 30 minutes to complete. senso duo

Magnetic Resonance Imaging Scanners

MRI scanners provide the radiologist with an image that is made by using magnetization of atoms, which highlight contrast between soft tissues. These devices are beneficial in obtaining soft tissue irregularities that cannot be seen using a CT scanner. With their capability and accuracy, they have proven to be remarkably beneficial in diagnosing conditions of the joint spaces, spinal cord and brain. MRI scanners also provide the advantage of the patient not being exposed to radiation. MRI images occur by using strong magnetic fields, computerized image processing and radiofrequency transducers. The MRI imaging scanner works by randomly aligning the nuclei of the body's molecules by means of a coil that is positioned around the patient to generate an energy pulse. Once the energy pulse is shut off or turned back on, the molecules go back to their positions. This causes signals to be detected, which are processed into images by the computer.

Positron Emission and Single Positron Emission Tomography

PET and SPECT medical scanning devices create images by radioactive tracers that are injected into the body by which gamma rays are emitted and then captured. Both PET and SPECT scanners provide information on functionality instead of anatomy. This could include the metabolism of glucose or the flow of blood. These scanning devices do not emit radiation into the patient, but are used to detect the radioactivity that has been injected into them. Although this can be worrisome to some individuals, the amount of radiation that is injected is given in carefully measured quantities that are safe. The radiation does not stay in the body, but naturally dissipates after several hours or within a few days. Images obtained by these scanners provide high-resolution images and can show active biological compounds in the body such as nitrogen, water, oxygen and carbon. These diagnostic tools are noninvasive and require 30 minutes to several hours to complete. Common exams include bone scans, gallium scans and stress myocardial exams. These types of scanners are very useful in detecting tumors.

Ultrasound Scanners

Ultrasound exams offer a painless and quick way to provide a diagnostic image. Sonograms or ultrasounds use frequencies that are produces by a transducer that is placed on the patient. The scanner has a material that will vibrate when it receives a voltage charge. This creates, transmits and refracts sound waves to the receiver. Using various types of transducers, they can be used on different parts of the body for imaging the heart, abdomen, and vascular system. Ultrasound scanners are also used during biopsies for collecting the sample using less invasive measures while providing more accuracy.

Breast Tomography

Due to the rapid increase in breast cancer among women and the inability to detect it in its early stages, doctors began looking for better ways to detect this form of cancer when it initially develops. By doing so, this could increase the chance of saving patients. This concern is what brought forth the breast thermograph-scanning device. This diagnostic tool is used specifically for detecting breast cancer in its early stages, as it is capable of providing detailed images of the breast and tissue that is beneath it. Breast tomography consists of graphing thermal levels of tissue that has become emaciated. Because the biological tissues within the body generate heat through constant metabolic actions, when high levels of heat are detected in the breasts by the tomography scanner, this provides the doctor with a clear diagnosis of tumor or cancer cells. The patient will then undergo additional testing to confirm the diagnoses so early treatment can be provided. Breast tomography is not intended as a replacement for mammography, but is used strictly for the purpose of early breast cancer detection.