Myelography is an x-ray examination of the spinal canal. A contrast agent is injected through a needle into the space around the spinal cord to display the spinal cord, spinal canal, and nerve roots on an x ray.he purpose of a myelogram is to evaluate the spinal cord and/or nerve roots for suspected compression. Pressure on these delicate structures causes pain or other symptoms. A myelogram is performed when precise detail about the spinal cord is needed to make a definitive diagnosis.
This is one of the only countries that doesnât touch the Pacific Plate. Instead it lies along the border of the Nazca and South American plates but is still considered to be part of the Ring of Fire. Chile records high levels of rainfall that add to earthquakes and tsunamis as natural disasters to be feared here. Chilean natural disasters include:
Alaska is part of the Pacific  Ring of Fire . It has over 70 volcanoes and every year thousands of earthquakes are reported in the state. In 1867 the United States bought Alaska from Russia for 7 million dollars. At that time many Americans were against this but as it turned out Alaska was a great investment. The state has a lot of mineral resources and is the biggest oil-producing state in the US. In the 1890s gold was found in the Yukon area of Canada.