字幕表 動画を再生する 英語字幕をプリント MRIs use protons, which are abundant in the human body. All protons spin creating a small magnetic charge. When a strong magnetic field is introduced, as is the case in an MRI machine, the protons align with that field. The MRI technician then introduces a radiofrequency pulse that disrupts the proton and forces it into either a 90 degree or 180 degree realignment with the static magnetic field. Since the radiofrequency pulse pushed the proton against its nature, once this pulse is turned off, the protons realign with the magnetic field, releasing electromagnetic energy along the way. The MRI is able to detect this energy, and is able to differentiate various tissues based on how quickly they release energy after the pulse is turned off.
B2 中上級 MRIはどのように機能するのか? (How Does an MRI Work?) 201 20 Cheng-Hong Liu に公開 2021 年 01 月 14 日 シェア シェア 保存 報告 動画の中の単語