Diagnostic imaging is a critical facet of health care. It allows physicians to diagnose patients without resorting to exploratory surgery. Ultrasound is an imaging modality that uses a safe form of radiation called sound waves. It can be used with other imaging modalities, such as computed tomography (CT) or magnetic resonance imaging (MRI) to acquire a more complete diagnosis. It can also be used by itself for certain types of imaging.
Obstetric Care
Obstetricians favor ultrasound over other imaging modalities because ultrasound does not have any known negative effects on the patient. For this reason, it is considered safe for imaging the rapidly developing fetus. Motion artifact, a blurred image, is less likely with ultrasound than with other modalities, so it is ideal for imaging the active fetus. Since ultrasound is safe, family members are allowed to sit in on the exam and watch their baby for the first time.
Breast Imaging
Mammography is the gold standard for breast-cancer screening. A mammogram shows the entire breast in one picture, which makes it difficult to miss any masses. Only a small section of the breast can be seen with ultrasound, which makes it less than ideal for a screening exam. It is useful for further imaging masses that have been found on mammogram. Mammography and ultrasound use different physical properties to form images. When used together, they are helpful for determining a more complete diagnosis.
Vascular Imaging
Ultrasound is distinctive from other imaging modalities in that it can measure the velocity of blood flow using Doppler, a technology that measures the speed of moving objects, such as blood cells. Increased velocities indicate arterial narrowing due to plaque buildup. It is a noninvasive procedure that is useful for evaluating the blood vessels of the arms, legs and neck. Unlike fluoroscopy, a form of X-ray, ultrasound does not require the use of dyes or radiation.
Reproductive Imaging
The reproductive organs and fertility can be negatively affected by the ionizing radiation of X-ray. Ultrasound is used to safely evaluate the uterus and ovaries in women and the testicles in men. Higher-frequency sound waves are used to acquire detailed images. Doppler is used to determine whether blood flow is normal in the ovaries or testicles. This can be done in emergency situations, so the ovarian or testicular torsion can be corrected in time to save the organ. Torsion occurs when the blood supply is cut off to the ovary or testicle.
Surgical Procedures
Ultrasound is useful for performing minimally-invasive procedures. It is used to visualize the location of needles during biopsies. The needle can be seen entering the mass that is the focus of the biopsy. Ultrasound is also useful for guiding catheters into blood vessels, such as with a PICC line, a device that is inserted into the arm of patients who receive intravenous medication several times per day.
Tags: imaging modalities, other imaging, other imaging modalities, blood flow, blood vessels
