Method for performing magnetic resonance spectroscopy or tomography in a preselectable region of a material

A method of performing magnetic resonance spectroscopy or tomography in a preselected sample region having a net nuclear magnetization direction and being positioned in a homogeneous external magnetic field having a field direction, said method comprising the steps of:

• A. applying a first constant magnetic field gradient having a direction to at least the preselected region for a predetermined time interval;
• B. during the predetermined time interval in step A, applying a first RF pulse to at least the preselected region, the RF pulse having a direction and magnitude selected to create a first nuclear magnetization component in a direction transverse to the field direction;
• C. applying a second RF pulse during the predetermined time interval in step A wherein said second rf pulse is a spin lock pulse;
• D. applying a third RF pulse to at least the preselected region, the third RF pulse having a direction and magnitude selected to transfer the first nuclear magnetization component into the field direction;
• E. removing the first constant magnetic field gradient;
• F. applying a fourth RF pulse to at least the preselected region, the fourth RF pulse having a direction and magnitude selected to create a second nuclear magnetization component in a direction transverse to the field direction;
• and
• G. detecting an induction signal produced by the second nuclear magnetization component.

A method of performing magnetic resonance spectroscopy or tomography in a preselected sample region having a net nuclear magnetization direction and being positioned in a homogeneous external magnetic field having a field direction, said method comprising the steps of:

• A. applying a first RF pulse to at least the preselected region, the RF pulse having a direction and magnitude selected to create a first nuclear magnetization component in a direction transverse to the field direction;
• B. applying, to refocus the first nuclear magnetization at a time t, a first constant magnetic field gradient having a direction to at least the preselected region for a predetermined time interval following the application of the RF pulse in step A;
• C. applying a second RF pulse during the predetermined time interval in step B wherein said second rf pulse is a spin lock pulse;
• D. removing the first constant magnetic field gradient;
• E. applying a refocusing gradient to produce a gradient echo;
• and
• F. detecting an induction signal produced by the gradient echo.

A method of performing magnetic resonance spectroscopy or tomography in a preselected sample region having a net nuclear magnetization direction and being positioned in a homogeneous external magnetic field having a field direction, said method comprising the steps of:

• A. applying a first constant field gradient having a direction to at least the preselected region for a predetermined time interval;
• B. during the predetermined time interval in step A, applying a first RF pulse to at least the preselected region, the RF pulse having a direction and magnitude selected to create a first nuclear magnetization component in a direction transverse to the field direction;
• C. applying a second RF pulse during the predetermined time interval in step A wherein said second rf pulse is a spin lock pulse;
• D. removing the first constant magnetic field gradient;
• E. applying a refocusing gradient to produce a gradient echo;
• and
• F. detecting an induction signal produced by the gradient echo.