Magnetic Resonance Imaging

What does MRI stand for? MRI stands for Magnetic Resonance Imaging. Below are some information and a picture of MRI equipment I obtain from Wikipedia about MRI and its uses.

Magnetic resonance imaging (MRI) is primarily a medical imaging technique most commonly used in Radiology to visualize the structure and function of the body. It provides detailed images of the body in any plane. MRI provides much greater contrast between the different soft tissues of the body than does computed tomography (CT), making it especially useful in neurological (brain), musculoskeletal, cardiovascular, and oncological (cancer) imaging. Unlike CT it uses no ionizing radiation, but uses a powerful magnetic field to align the nuclear magnetization of (usually) hydrogen atoms in water in the body. Radiofrequency fields are used to systematically alter the alignment of this magnetization, causing the hydrogen nuclei to produce a rotating magnetic field detectable by the scanner. This signal can be manipulated by additional magnetic fields to build up enough information to reconstruct an image of the body.

MRI is a relatively new technology, which has been in widespread use for less than 20 years (compared with over 100 years for X-rays). The first MR Image was published in 1973 and the first study performed on a human took place on July 3, 1977.

Magnetic resonance imaging was developed from knowledge gained in the study of nuclear magnetic resonance. In its early years the technique was referred to as nuclear magnetic resonance imaging (NMRI). However, as the word nuclear was associated in the public mind with ionizing radiation exposure it is generally now referred to simply as MRI. Scientists still use the term NMRI when discussing non-medical devices operating on the same principles. One of the contributors to modern MRI, Paul Lauterbur, originally named the technique zeugmatography, a Greek term meaning "that which is used for joining". The term referred to the interaction between the static and the gradient magnetic fields necessary to create an image, but this term was not adopted.

WHO: Swine Flu Cases Top 2,000

The World Health Organization says the swine influenza A-H1N1 virus has infected more than 2,000 people worldwide.

The WHO says the swine flu has spread across 23 countries, though most of the cases have been reported in Mexico and the United State

Earlier Thursday, the WHO's acting director-general Keiji Fukuda told Asian officials in Bangkok by videolink that the WHO does not know how severe the swine flu outbreak will become. He warned the virus could get more virulent later in the year during the northern hemisphere's flu season.

If it turns into a pandemic, he said one third of the world's population - up to two billion people - could end up infected.

The United States has confirmed nearly 900 cases of swine flu, while Mexico has reported more than 1,000.

The acting director for the Centers for Disease Control (CDC) Richard Besser said officials expect to see far more cases in the U.S., as well as more deaths. Two fatalities have already been confirmed in the U.S. state of Texas, which borders Mexico, while all 42 other deaths from the virus occurred in Mexico.

Mexican businesses and schools began reopening Wednesday and Thursday after officials said the virus was spreading more slowly in the country.

Other countries have also been easing measures to control the disease.

China on Thursday lifted a seven-day quarantine for passengers who arrived in Shanghai on a flight with a Mexican man who was later found to be infected with the virus.

Also Thursday, Russia announced it was lifting a ban on meat imports from five U.S. states, but added another - Illinois - to its list.

At a Congressional hearing Thursday, U.S. Agriculture Secretary Tom Vilsack said he is disappointed that Russia and China have imposed restrictions on U.S. imports.

Vilsack stressed that U.S. pork products are safe, saying there is no evidence the swine flu virus can be transmitted through food. He said the agriculture department is working hard to reach out to the Russians, the Chinese and other governments to reopen international markets.

By VOA News
07 May 2009

Hypertension

Hypertension, most commonly referred to as "high blood pressure", HTN or HPN, is a medical condition in which the blood pressure is chronically elevated. It was previously referred to as nonarterial hypertension, but in current usage, the word "hypertension" without a qualifier normally refers to arterial hypertension.

Hypertension can be classified either essential (primary) or secondary. Essential hypertension indicates that no specific medical cause can be found to explain a patient's condition. Secondary hypertension indicates that the high blood pressure is a result of (i.e., secondary to) another condition, such as kidney disease or tumours (pheochromocytoma and paraganglioma). Persistent hypertension is one of the risk factors for strokes, heart attacks, heart failure and arterial aneurysm, and is a leading cause of chronic renal failure. Even moderate elevation of arterial blood pressure leads to shortened life expectancy. At severely high pressures, defined as mean arterial pressures 50% or more above average, a person can expect to live no more than a few years unless appropriately treated.

Hypertension is considered to be present when a person's systolic blood pressure is consistently 140 mmHg or greater, and/or their diastolic blood pressure is consistently 90 mmHg or greater. Recently, as of 2003, the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure has defined blood pressure 120/80 mmHg to 139/89 mmHg as "prehypertension." Prehypertension is not a disease category; rather, it is a designation chosen to identify individuals at high risk of developing hypertension. The Mayo Clinic website specifies blood pressure is "normal if it's below 120/80" but that "some data indicate that 115/75 mm Hg should be the gold standard." In patients with diabetes mellitus or kidney disease studies have shown that blood pressure over 130/80 mmHg should be considered high and warrants further treatment.

Hypertension is labeled resistant if a person’s blood pressure remains above their target blood pressure despite taking three or more medications to lower it. The American Heart Association released a scientific statement in May 2008 with guidelines for treating resistant hypertension.

Source: Wikipedia

Calcium

Calcium is an important component of a healthy diet. Calcium is essential for the normal growth and maintenance of bones and teeth, and calcium requirements must be met throughout life.

Long-term calcium deficiency can lead to osteoporosis, in which the bone deteriorates and there is an increased risk of fractures. While a lifelong deficit can affect bone and tooth formation, over-retention can cause hypercalcemia (elevated levels of calcium in the blood), impaired kidney function and decreased absorption of other minerals. High calcium intakes or high calcium absorption were previously thought to contribute to the development of kidney stones.

However, more recent studies show that high dietary calcium intakes actually decrease the risk for kidney stones. Vitamin D is needed to absorb calcium. Dairy products, such as milk and cheese, are a well-known source of calcium. However, some individuals are allergic to dairy products and even more people, particularly those of non Indo-European descent, are lactose-intolerant, leaving them unable to consume non-fermented dairy products in quantities larger than about half a liter per serving. Others, such as vegans, avoid dairy products for ethical and health reasons.

Fortunately, many good sources of calcium exist. These include seaweeds such as kelp, wakame and hijiki; nuts and seeds (like almonds and sesame); blackstrap molasses; beans; oranges; figs; quinoa; amaranth; collard greens; okra; rutabaga; broccoli; dandelion leaves; kale; and fortified products such as orange juice and soy milk. An overlooked source of calcium is eggshell, which can be ground into a powder and mixed into food or a glass of water. Cultivated vegetables generally have less calcium than wild plants.

Source: Wikipedia

Osteoporosis (Part 2)

Signs and symptoms

Osteoporosis itself has no specific symptoms; its main consequence is the increased risk of bone fractures. Osteoporotic fractures are those that occur in situations where healthy people would not normally break a bone; they are therefore regarded as fragility fractures. Typical fragility fractures occur in the vertebral column, hip and wrist.

Fractures

The symptoms of a vertebral collapse ("compression fracture") are sudden back pain, often with radiculopathic pain (shooting pain due to compression of a nerve) and rarely with spinal cord compression or cauda equina syndrome. Multiple vertebral fractures lead to a stooped posture, loss of height, and chronic pain with resultant reduction in mobility.

Fractures of the long bones acutely impair mobility and may require surgery. Hip fracture, in particular, usually requires prompt surgery, as there are serious risks associated with a hip fracture, such as deep vein thrombosis and a pulmonary embolism, and increased mortality.

Falls risk

The increased risk of falling associated with aging leads to fractures of the wrist, spine and hip. The risk of falling, in turn, is increased by impaired eyesight due to any cause (e.g. glaucoma, macular degeneration), balance disorder, movement disorders (e.g. Parkinson's disease), dementia, and sarcopenia (age-related loss of skeletal muscle). Collapse (transient loss of postural tone with or without loss of consciousness) leads to a significant risk of falls; causes of syncope are manifold but may include cardiac arrhythmias (irregular heart beat), vasovagal syncope, orthostatic hypotension (abnormal drop in blood pressure on standing up) and seizures. Removal of obstacles and loose carpets in the living environment may substantially reduce falls. Those with previous falls, as well as those with a gait or balance disorder, are most at risk.

Sumber: Wikipedia

Osteoporosis (Part 1)

Osteoporosis is a disease of bone that leads to an increased risk of fracture. In osteoporosis the bone mineral density (BMD) is reduced, bone microarchitecture is disrupted, and the amount and variety of non-collagenous proteins in bone is altered. Osteoporosis is defined by the World Health Organization (WHO) in women as a bone mineral density 2.5 standard deviations below peak bone mass (20-year-old healthy female average) as measured by DXA; the term "established osteoporosis" includes the presence of a fragility fracture.^[1] Osteoporosis is most common in women after menopause, when it is called postmenopausal osteoporosis, but may also develop in elderly men, and may occur in anyone in the presence of particular hormonal disorders and other chronic diseases or as a result of medications, specifically glucocorticoids, when the disease is called steroid- or glucocorticoid-induced osteoporosis (SIOP or GIOP). Given its influence on the risk of fragility fracture, osteoporosis may significantly affect life expectancy and quality of life.

Osteoporosis can be prevented with lifestyle advice and sometimes medication, and in people with osteoporosis treatment may involve lifestyle advice, preventing falls and medication (calcium, vitamin D, bisphosphonates and several others).

Source: Wikipedia