selected TR shorter in order for the tissue to regain the longitudinal magnetization and the subsequent RF pulses are affected by the partial saturation. This makes the fat vector gain more longitudinal magnetization as compared to water and create fat to appear brighter on the T1weighted image. T2 weighted image
After the RF pulses are applied to the spins, the spin interaction appears. This causes the T2 to decay due to the nuclei interaction in the magnetic fields in the region. This also reduces the transverse magnetization. It is also imperative to note that the water and the fat have varying T2 decay. This is mainly caused by the rapid exchange of energy. The fat have very short T2 TIME, on the other hand, the processing of water has very long T2 TIME DUE TO ITS INEFICINCY. The TE is responsible for controlling the amount of decay (T2) appearing before the reception of the signals. Therefore to acquire a very clear difference between the water and the fat, it is advisable to increase TE and TR. this is because fluid always appear brighter in these images ac compared tom solid because of the high level of signal intensity.
This is also referred to as spin density as kit represents the quantity of protons inside the object (tissue) being imaged. It is important to note that there are tissues that have little proton like the cortical bone and the air, these tissues produce little signals. On the other hand, there are tissues that have a lot of proton contents. These classes of tissues include the brain and are manually characterised by high ability to of creating a high. The proton density and the T2 images can be easily acquired in a single sequence (double echo). This process uses the long TR and short TE. The first echo is achieved by use of the long TR and the short TE, while the second echo is achieved by long TE and long TR to acquire the T2 weighted images. Proton density is just a representation if the number of hydrogen atoms that are in the