Compare and contrast the scientific principles of Magnetic resonance Essay

Compare and contrast the scientific principles of Magnetic resonance imaging (MRI) and ultrasound - Essay Example However, there are similarities and differences of these radiographic techniques in terms of scientific principles behind these, by which this paper intends to explore. Transmission and Reception of Waves. Magnetic resonance imaging and ultrasound shares their similarity in their ability to transmit their respective waves, electromagnetic and acoustic waves respectively, while receiving the signals induced by these transmitted waves. In magnetic resonance imaging, transmit coils emit radio waves to the patient, calibrated at the precessional frequency or Larmor frequency of hydrogen-1 at 42.6 MHz under a magnetic field strength of 1.5 tesla or above, generates a strong magnetic signal within the hydrogen-1 nucleus which can be detected by the receiver coils of the device1. On the other hand, in ultrasound, ultrasonic acoustic waves come from the source transducer as a result of a piezoelectric effect (conversion of electrical to sound energy), and solid objects along the watery body tissues causes an echo, which will be detected by the receiving transducer using the same piezoelectric effect (conversion of sound energy to electrical energy)2. Type of Waves. There are differences between electromagnetic waves emitted by magnetic resonance imaging and the acoustic waves of ultrasound imaging, mainly on the speed of wave travel (electromagnetic waves are faster than acoustic waves), ability to travel in an empty space (acoustic waves cannot travel in a vacuum while electromagnetic waves can), and the type of waves traveling along fluid (longitudinal and transverse in electromagnetic waves, while longitudinal only in acoustic waves), yet both electromagnetic and acoustic waves are similar to be having properties of frequencies, amplitude, intensity2. How these properties are used in both devices is also dissimilar (the frequency of electromagnetic waves in MRI is set to a standard 42.6 MHz setting, while the frequency in ultrasound is calibrated according to the de pth of penetration)1 2. Non-use of ionizing radiation. Both magnetic resonance imaging and ultrasound do not utilize ionizing radiation present in x-ray, computerized tomography and fluoroscopy. In magnetic resonance imaging, the electromagnetic wave frequency of 42.6 MHz is very low to cause ionization of molecules, while acoustic waves are not a type of radiation which causes ionization of molecules even in high frequencies2. Body Temperature Elevation. Both magnetic resonance imaging and ultrasound produces heat. Heat is a form if energy, which can be appreciated in thermodynamics as â€Å"internal energy† in terms of excitement of molecules. From elastic energy, while the waves are being deformed by compression and rarefaction, there is energy transformation into heat or thermal energy which can be absorbed by the system3. Waves, whether it is radio frequency electromagnetic or acoustic, has the property of intensity, which is the power output per area (I = P / A) while e nergy can be computed as power over a period of time (E = P / t). If power will be substituted, energy is equal to the product of intensity and area, divided by time (E = [I x A] / t). By this formula, it is already clear that energy is involved in waves. Assuming that the wave is at rest, the energy of a wave is its potential energy. However, if the wave is put in motion, this potential energy will be