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• 1.5 T superconducting MRI

  A horizontal-bore superconducting scanner. A persistent main field, three gradient axes and radiofrequency coils work together to acquire signals. The console controls a sequence; it does not photograph the patient directly.

• 3 T superconducting MRI

  A higher-field horizontal-bore scanner with a superconducting magnet, gradient insert and radiofrequency chain tuned for its field. More available signal can support a different resolution or time trade-off; it is not a universal promise of a better examination.

• Open permanent-magnet MRI

  3 T permanent-magnet system with two opposing pole faces and a vertical main field. The patient lies in an open gap. Planar gradients and a compatible radiofrequency coil still encode and receive the signal.

• From alignment to excitation

  Begin with the steady field. The net magnetisation has a longitudinal component. A controlled radiofrequency pulse changes its direction; the transverse component can contribute to a received signal.

• Give the signal a spatial address

  A received waveform mixes contributions from many places. Gradient fields let the system distinguish position through controlled frequency and phase changes. Slice selection also involves an appropriately designed radiofrequency pulse.

• Make contrast a deliberate choice

  The same phantom can look different under different sequence weightings. Tissue-related relaxation, timing and readout choices affect signal. Select each weighting and compare regions rather than judging the whole image as simply better or worse.

• Separate motion from RF interference

  A technical image problem has a pattern and a context. Motion can create displacement or ghosts; unwanted radiofrequency energy can create structured interference. Turn on one teaching disturbance at a time and compare with baseline.

• Main magnet

  The magnet establishes the steady field around which the rest of MRI is organised. It changes the balance and behaviour of nuclear magnetisation; it does not emit the image.

• Shim system

  Shimming improves how uniform the main field is over the region being examined. If different places experience unintended frequency differences, signal and geometry can suffer.

• Gradient coil assembly

  Gradients deliberately make resonance depend on position. That gives a received signal a spatial address.

• Radiofrequency transmit structure

  A brief radiofrequency field tips the net magnetisation away from equilibrium. That prepares a measurable transverse signal.

• Local receive coil

  The coil close to the anatomy detects a small changing electromagnetic signal. Placement matters: a technically impressive scanner still needs a suitable receiving path near the region of interest.

• Coil connection interface

  This is the boundary between a removable patient-side coil and the scanner receiving system. Correct mechanical engagement does not automatically prove the electrical channels are intact.

• Patient table and drive

  The table positions the anatomy in the intended imaging region. Its indicated coordinate is useful only when the patient, coil and landmark agree with it.

• Positioning controls and landmark

  A landmark connects the physical patient position to the planned scan volume. The operator uses the prescribed positioning method rather than guessing from the shell opening.

• Hearing protection

  Gradient switching makes the acoustic environment part of preparation. Protection must fit and be suitable for the examination; placing an accessory near the patient is not the same as providing effective protection.

• Patient call system

  The patient needs a reliable way to report discomfort or request attention. The call device closes a human feedback loop that image acquisition alone cannot provide.

• The missing receive channel

  The coil is not fully recognised. What happens next?

• The image that will not hold still

  The patient reports discomfort during acquisition. What is the next priority?

• The stripe that survives a repeat

  The pattern persists with a stationary phantom. Which comparison is useful?

• Acquisition stops, the magnet remains

  The stop has interrupted scanning. Which statement is safe?

Training cases written by BMEssentia for teaching.

• Medical Device Mastery
• Equipment Procurement
• Patient Safety Investigator
• Medical Technology Detective

• IEC 60601-1
• IEC 62353
• IEC 60601-2-33

• Philips Ingenia 1.5T
• GE SIGNA Explorer 1.5T
• Siemens MAGNETOM Aera 1.5T