Ultrahigh resolution magnetic resonance imaging method and apparatus

A magnetic resonance imaging apparatus comprising:

• a static magnetic source, for forming a static magnetic field in a space where the test sample locates;
• a radio-frequency source, for exciting the nuclear magnetic resonance of the test sample;
• a magnetic gradient source, for forming a gradient magnetic field in the space where the test sample locates;
• a detector, which is a nano-scale superconducting quantum interference device, for directly coupling the test sample to detect the nuclear magnetic resonance spectrum signals generated by nuclear spins of the test sample;
• an image forming apparatus, for constructing an image of the test sample according to the nuclear magnetic resonance spectrum signals detected by the detector;
• wherein, the nano-scale superconducting quantum interference device detects the nuclear magnetic resonance spectrum signals generated by nuclear spins of the test sample by the following steps of:
• inputting a predetermined current pulse to the nano-scale superconducting quantum interference device to make it work at an operating point;
• coupling the nano-scale superconducting quantum interference device with the test sample to make the nano-scale superconducting quantum interference device a deviation from the operating point as magnetic flux changing;
• using a programmable logic circuit to perform a proportional-integral-derivative (PID) feedback logic operation, fixing the nano-scale superconducting quantum interference device back to the operating point by applying a feedback signal on the nano-scale superconducting quantum interference device through a current source controlled feedback circuit;
• and
• obtaining the nuclear magnetic resonance spectrum signals of the test sample by measuring feedback quantity of the feedback circuit.