Using the rotating frame method, let us analyze what happens to M or individual spins when the B 1 field is applied at a frequency that exactly matches the Larmor precession. Application of B1 field rotating/oscillating at Larmor frequency viewed from the laboratory frame.

Magnetic resonance imaging (MRI) is a medical imaging technique mostly used in radiology and nuclear medicine in order to investigate the anatomy and physiology of the body, and to detect pathologies including tumors, inflammation, neurological conditions such as stroke, disorders of muscles and joints, and abnormalities in the heart and blood ...

The flip angle is the angle between the B1 field and the B0 field at the time of excitation. When the B1 field is applied, it exerts a torque on the nuclear spins, causing them to rotate away from …

Flip angle, also called tip angle, is the amount of rotation the net magnetization () experiences during application of a radiofrequency (RF) pulse. It is often designated by the Greek letter alpha (α) and can be measured in degrees (°) or radians (R). For conversion 360° = 2π radians. α …

Feb 5, 2025 · When you call the ft_volumereslice function on the anatomical MRI, it will apply the transformation matrix to the field anatomy and interpolate the anatomical data onto a new voxel-grid that is aligned with the axis of the head coordinate system.

Reorient (https://neuroanatomy.github.io/reorient) is an open source Web application for the manual alignment and cropping of MRI nifti volumes in an intuitive way. The MRI data is dragged onto the Web interface and visualised in an interactive stereotaxic viewer.

ABduction and External Rotation (ABER) sequence in magnetic resonance (MR) arthrography of the shoulder is particularly important to better depict abnormal conditions of some glenohumeral joint structures and surrounding tissues by making imaging possible under a stress position relevant to pathologic conditions.

Jul 21, 2007 · It rotates about its axis and it rotates at a particular frequency. And the same is true of a hydrogen nucleus, the proton at the centre of a hydrogen atom, when you put that into a magnetic field it’ll tend to rotate, and that rotation speed, the …

The torque on magnet due to the magnetic field will cause it to rotate ("precess") about the magnetic field. The frequency of this rotation is equal to the strength of the magnet times that of the magnetic field - this is called nuclear magnetic resonance (NMR).

To create a signal in MR, we use a brief “radiofrequency” pulse of energy of typically 10-1000 watts. The RF energy oscillates at exactly the Larmor frequency and appears to the spinning protons as a new magnetic field, B1, which is moving at the rate that they are. Protons then are redirected toward this new field.