방사선사나라 Radiographer Nara

(English)3D TOF MRA? This is a method of acquiring a 3D image by performing z-axis encoding in the slice selection direction in addition to the frequency direction and the phase direction. Like 2D TOF MRA, it is a method that uses the flow related signal enhancement phenomenon of the inflowing blood flow and is the most used method to view the vessels of the head.Compared to 2D TOF MRA, SNR is b..

(English) 2D TOF MRA? It is basically a blood flow compensation gradient echo imaging technique. The stationary spin in tissue in the imaging slice is saturated by the RF pulse, but the blood flow entering the imaging slice is completely magnetized and shows high signal intensity. If a saturation (presaturation) pulse is applied above or below the selected slice, all signals of blood flow coming..

(English) TOF (Time Of Flight)? It is commonly used in blood flow compensation gradient echo images by using the flow related signal enhancement effect. Basically, spin is readout after a certain period of time after being selected as a single RF. If the position of the spin is changed between these time intervals, TOF effect appears and the blood flow is seen as a high signal intensity by the R..

(English) MRA(Magnetic Resonance Angiography)? A field of MRI that provides non-invasively morphological information of blood vessels By maximizing the signal intensity of the blood flow and minimizing the signal from the stationary material, the images obtained by maximizing the contrast among the protons are obtained by using the MIP(Maximum Intensity Projection) method. MRA is divided into co..

(English) Why blood vessels look bright on MR images 1. Entry slice phenomenon In the multi-slice imaging method, entry slice phenomenon occurs when unsaturation spins in blood first enter into slices. It is characterized by the bright signal in a blood vessel (artery or vein) at the first slice that the vessel enters. 2. Even-echo signal rephasing The dephased spin is rephased to produce a high..

(English) How can we get Black Blood MR images? 1. Using presaturation technique The most common method is the presaturation technique. This applies a presaturation RF waveform before selecting the slice, causing the blood to darken in the selected slice. The anterior part of the direction in which blood enters the selected slice must be saturated. In doing so, the blood entering the selected sl..