The Main Uses of Ultrasound in Actual Departments or Centres - Coursework Example

Introduction Ultrasound is the exposure of part of the human body to high frequency sound waves. These waves are then reconstructed into pictures of the inner parts of the body usually obstructed from external view. It is also known as ultrasound scanning or sonography. The images are captured in real time thus they can show activities of the inner body organs taking place at the time of viewing. First used at the Naval Medical Research Institute for human treatment by Dr. George Ludwig, in Bethesda, Maryland in the 1940s, ultrasound has proved to be the most reliable way of getting accurate and vivid reality check of what is going on inside the body. Because of the clarity of the images, especially the 3 dimension and 4 dimension types, it is now possible to view the development of the foetus in the womb and the nature of a timorous growth in the breast among others. Vascular and Imaging Ultrasound Vascular ultrasound is used to view pictures of the body’s blood vessels. The vessels are made up mainly of veins and arteries, which are differentiated by the direction in which they carry blood flow in relation to the heart. Veins carry blood into the heart while arteries carry it away from the heart. Vascular sonographies are therefore important in helping doctors to view the flow of the blood and any blockages or constrictions in the vessels carrying it. In this way, causes of problems such as strokes or coronary malfunctions can be easily identified1. A variety of this ultrasound technique is the Doppler technique, which is used specifically to measure the rate of blood flow in the vessels. It is obviously a very important intervention in case of hypertension. The Doppler technique helps in imaging the rate and direction of the flow of blood. It contrasts the blood from the vein by for instance showing the veins as blue in color while the blood is red. The colorful images shown are not only picturesque and breathtaking but also give a very accurate display of the flow. Problems such as blockages or interruptions can also be easily noticed2. The type of sonography known as imaging is a noninvasive test method that enables medical practitioners to examine internal organs of the body without necessarily cutting the patient open. It specifically concentrates on a particular organ for a definite purpose. This imaging falls into three main categories. The first is the A-mode in which a single sound wave is used to scan a strait line in the body giving its image in terms of depth. This applies to the scanning of a tumor for instance. The B-mode involves a number of transducer rays simultaneously scanning an organ on a plane thus giving a 2 D image of it. The focus here is mainly on the surface details of the organ under scan. The M-mode is where the transducer is moved around, for example on different angles along the distended stomach of a pregnant lady. This helps to create a 3 D image and gives a more detailed analysis of the object. This can be taken to higher level to see the image even from the side left out in the 3 D view thus creating a clearer 4 D image3. The difference between the vascular and imaging ultrasounds is therefore not in the method but in the target part of the body. In general terms however most hospitals just have one department of ultrasound and do not differentiate between the two varieties. An example in point is the Florida hospital, which runs all types of ultrasound in the same department. The personnel involved can also run either test. The same scenario recurs in other hospitals, as the varieties of ultrasound are not differentiated. How Ultrasound Works The term ultrasound refers to high frequency sound waves that cannot be detected by the human ear because they are too high. The sounds are developed using electrical impulses that are transformed into sound energy at the point of a probe known as a piezoelectric transducer. The transducer produces sounds ranging from 2-18 megahertz frequency. When the transducer is placed on the surface of the skin, it sends the sound waves into the body to the required depth in a particular direction4. The echoes of the sounds come back to the transducer, which then graphs them according to time taken, and intensity. These graphs help produce the desired image. Higher frequencies enhance clearer images while lower frequencies ensure that the image deeper penetration. So while the brain is imaged at 7-18 megahertz to provide a better axial and lateral resolution, the liver is imaged at 2-6 megahertz to provide for greater depth penetration5. The sonographer selects the image accordingly depending on the test being carried out. Moving the probe around helps to enhance the image from a 2 D to a 3D image. It is important to note that certain specialized transducers can be inserted into the body as well to carry out better internal examination of tissues. These can be inserted transvaginally for females and transrectally for males to carry out pelvic examinations. Uses of Ultrasound Ultrasound can be used both for diagnostic and therapeutic purposes. The diagnosis of problems such as tumors and organ leaks can be done using this method just like ultrasonic therapy to develop heat for treating of tumors such as in the process known as Focused Ultrasound Surgery (FUS)6. Diagnostic Uses The most renowned use is the obstetric ultrasound imaging of feotuses. Expectant women now have the advantage of viewing their unborn babies as clearly as if they were already in the outside world. The process involves the transducer being placed against the belly of the mother, with the detected sound waves being reconstructed on a monitor. The depending on the level of advancement in the machine used, the image can range between a 2 dimension black and white picture, to a high definition 3 dimension one. In places like the Mirror Imaging Ultrasound located in Cincinnati Ohio, high quality pictures enable the mother to see the baby’s appearance, and can show actions such as blinking, yawning, as well as finger and foot movements7. They also have the 4 dimension imaging which enables the view of the feotus from different angles and specific details such as curvatures on the face. All these images are possible from mid pregnancy onwards 8. Another use of the procedure is in the detection of lymphangiomas which are cyst lesions occurring mostly in the in the neck. These cysts need imaging before they are operated on. This helps surgeons to know exactly where the cyst is located and helps them to make crucial decisions on how to remove them9. Apart from the obvious curiosity to find out the sex of their children, there are other advantages of taking this ultrasound observation. The most important one is that the obstetricians are able to carry out prenatal observations on the progress of the pregnancy. Through the sonography, they can detect development anomalies that could lead to complications. The tests can also be used to confirm a pregnancy, the due date of birth and even the age, size and growth of the foetus. A more frivolous but popular reason all the same is the need for family members to bond with their unborn siblings. This is mainly driven by the uncontrolled nature of human curiosity, since there is still a bit of a monkey in all of us10. Another major use of sonography is in the treatment of strokes. Though they occur for various reasons, strokes mainly have to do with shortage of blood, oxygen or energy supply to the brain. This can be due to blood flow malfunctions or diseases such as anemia. Ultrasound scans can be used to determine the amount and nature of neural damage caused by the stroke. Neurological ultrasound assessments are useful in observing the flow of blood and stenoses present in carotid and intracerebral arteries. These help to determine the rate of delivery of blood to the brains11. Abdominal sonography involves the imaging of solid organs of the abdomen such as the pancreas, vena cava, gall bladder, kidneys and spleen. The inflamed appendix can also be detected through this method. Any anomalies in these organs can thus be identified to be treated as required. The procedure can be used to detect Abdominal Aortic Aneurysm (AAA). This is a localized dilation of the aorta in the abdomen beyond the normal diameter by an extra 50%. It is usually attributed to the degeneration of the wall of the aorta though its exact etiology is still a mystery. Most abdominal aortic aneurysms occur below the kidneys (infrarenally), but they can also occur pararenally (level with) or suprarenally (above). AAA can extend to both of the iliac arteries in the pelvis12. Imaging of the bowels is however still not really possible due to gasses therein interfering with the passage of sound waves. All of these organs have a variety of problems that the ultrasound scan can help in detecting. The amount of urine left in the gall bladder after normal urination for example can be seen. This helps in determining whether the bladder is malfunctioning and is thus subject to infections13. In pelvic sonography, the organs around the pelvis such as the ovaries, uterus and urinary bladder are viewed. Problems in these organs may lead to infertility related complications14. It is therefore important for gynecologists to know exactly what the nature of the problem is so as to determine the action to be taken. The prostate in men is also observed using this method. Medical personnel can detect conditions such as a pelvic prolapse and constricted defecation too through ultrasound tests to guide interventions15. Therapeutic Uses Therapeutic applications are generally applied to bring heat and stimulation to body tissues. This heating requires that the high frequencies used for imaging purposes are traded for lower frequencies but higher energy levels16. One use of the process is to perform simple surgical operations to eliminate small tumors or cysts. When it is a mild operation it is known as Focused Ultrasound Surgery FUS while a more intensive form is called High Intensity Focused Ultrasound (HIFU). This involves the directing of a highly localized heat at the target area for a duration ranging from minutes to even a few hours. Much lower frequencies of ultrasound of between 250-2000 kilohertz are used as this ensures that higher energy levels are generated. The procedure is also quite useful in breaking up kidney stones17. The low frequency ultrasounds can also be used to stimulate the growth of bones. Where bones are fractured this method can be used to stimulate faster growth, so as to speed up the recovery of the patient. The therapy also helps to break down barriers between the blood and the brain to enable the delivery of drugs to the brain. The barrier occurs due to constricted veins or impurities that inhibit the blood carrying capacity of drugs and other nutrients. The same ultrasounds are used to clean teeth for purposes of dental hygiene. Conclusion The introduction of ultrasound into the medical profession was a great revolutionary act. Not only has it changed the way in which the internal organs of the body are observed and tread, but it has no real documented side effects. Unlike the use of X-rays which may affect the body if it is exposed directly, the ultrasound is merely sound and thus does not affect the body. Even though to be on the safer side organizations such as the US Food and Drug Administration recommends that it be used only when necessary, it remains on of the safest and most useful methods of internal body medical interventions. References Cline H. E. et al, 1992. “MR-guided focused ultrasound surgery,” J Comput Assist Tomogr 16(6), 956-65 Florida Hospital. 2009. Ultrasound at Florida Hospital. www.florida hospital.org. Retrieved 13 Oct 2009. Fosse E. 2006. Thermal ablation of benign and malignant tumours. Minim Invasive Therapy Allied Technol; 15:2-3 Guirguis EM, Barber GG. The natural history of abdominal aortic aneurysms. Am J Surg 1991; 162(5):481–483. Illing RO et al, 2005. The safety and feasibility of extracorporeal high.intensity focused ultrasound (HIFU) for the treatment of liver and kidney tumours in a Western population. Br J Canc; 93:890-895 Kundu, Tribikram 2004. Ultrasonic nondestructive evaluation: engineering and biological material characterization. Boca Raton, FL: CRC Press. Lafon C et al 2007. Interstitial devices for minimally invasive thermal ablation by high-intenstiy ultrasound. Int. J. Hyperthermia; 23(2):153-163 Leslie TA et al, 200. High intensity focused ultrasound in the treatment of abdominal and gynaecological disease. Int. J. Hyperthermia; 23(2):173-182 Nano G. et al 2008. “Diagnosis and treatment of abdominal aortic endoleaks using color Doppler US: Two clinical cases” Journal of Ultrasound. 171-173. Neilson JP, 2009. Ultrasound for fetal assessment in early pregnancy, The Cochrane Collaboration, Nevitt MP, Ballard DJ, Hallett Jr JW. Prognosis of abdominal aortic aneurysms. A population-based study. N Engl J Med 1989; 321(15):1009–1014. Novelline, Robert (1997). Squires Fundamentals of Radiology (5th ed.). Harvard University Press. pp. 34–35. Valma J Robertson, Kerry G Baker (2001). "A Review of Therapeutic Ultrasound: Effectiveness Studies". Physical Therapy 81 (7): 1339. http://www.ptjournal.org/cgi/content/short/81/7/1339 Vargas-Serrano et al.1994. “Radiology in the Department of Diagnostic Radiology, Hospital Severo Ochoa, Avda. de Orellana s/n, 28911 Legan~s-Madrid, Espaffa” in European Journal of Radiology 19 (1995) pp 183-187 Wolf YG, Bernstein EF. A current perspective on the natural history of abdominal aortic aneurysms. Cardiovasc Surg 1994; 2(1): 16–22. Wu F et al 2005. Advanced hepatocellular carcinoma: Treatment with high-intensity focused ultrasound ablation combined with transcatheter arterial embolization. Journal of Radiology; 235:659-667 Read More