T2* can be considered an observed or effective T2, whereas the first T2 can be considered the natural or true T2 of the tissue being imaged. T2* is always less than or equal to T2. T2* results principally from inhomogeneities in the main magnetic field.These inhomogeneities may be the result of intrinsic defects in the magnet itself or from susceptibility-induced field distortions produced by the tissue or other materials placed within the field.2* can be considered an observed or effective T2, whereas the first T2 can be considered the natural or true T2 of the tissue being imaged. T2* is always less than or equal to T2. T2* results principally from inhomogeneities in the main magnetic field.
The average electricity consumption of a US family of four is in the neighborhood of 50 kWh per day, or 1,500 kWh per month. Similar figures apply for Canada. Assuming an average electricity cost of $0.12 per kWh, that translates into about $6 per day for electricity, or $180 per month.
Here is an example of our usage, for the 12 months between 27th May 2008 and 27th May 2009: 8,587 kWh Peak usage. 4,441 kWh Off Peak Usage. This is a total of 13,028 kWhs per year, (35.7 kWh per day) compared to the Australian national average Electricity consumption of 6,570 kWhs per year (18 kWh per day).