Point your right-hand thumb along the main MRI field (B0). The direction your fingers curl shows how proton magnetic moments and net magnetization precess around B0. Conversely, if you align your fingers with the proton precession, your thumb points in the direction of the magnetic moment (and the polarity of the induced signal in a receive coil). Use this to determine orientation and induced current.

MRI of the hand is a non-invasive imaging test using magnetic fields and radio waves to produce detailed cross-sectional images of bones, joints, cartilage, ligaments, tendons and nerves. It helps diagnose fractures, ligament or tendon tears, arthritis, infections, cysts or tumors, and unexplained pain or swelling. Exams take about 20–45 minutes, may use contrast, and avoid ionizing radiation; metal implants or pacemakers can be contraindications.

A right-hand MRI starts with safety screening and removing metal jewelry; you change into a gown. You lie on the scanner table and the technologist positions the right hand inside a dedicated coil, often immobilized with cushions or straps. Ear protection is given; contrast may be injected if needed. The table advances into the magnet, you must stay still while images are taken; the scan takes about 15–30 minutes.

A hand MRI provides detailed images of bones, joints, cartilage, ligaments, tendons, nerves and surrounding soft tissues. It can detect tears, inflammation, bone‑marrow edema, occult fractures, arthritis, ganglion cysts, infections, tumors and nerve entrapment (e.g., carpal tunnel). Contrast may be used to highlight infection or tumors. Results guide diagnosis and treatment planning.

The right-hand rule is a mnemonic for determining direction of vector cross products and magnetic effects: point your index finger in the first vector (velocity or current), middle finger in the second (magnetic field), and your thumb shows the resulting force or direction of the cross product. For coils, curling your fingers shows magnetic-field direction while your thumb points along the coil’s axis.

On MRI, right and left refer to the patient’s sides. By radiological convention images are displayed as if you are facing the patient’s feet, so the patient’s right appears on the image’s left and the patient’s left on the image’s right. Most scans include R/L markers—check those or the radiology report to confirm orientation, since some displays use an anatomical view.