DO NOT BEGIN BY RANDOMLY CHANGING PARAMETERS
First decide whether the problem is safety, anatomy, acquisition, reconstruction, or equipment.
An artifact can come from the patient, physiology, positioning, coil setup, sequence design, spatial encoding, reconstruction, hardware, or the surrounding RF environment. More than one cause may be present.
A strong troubleshooting process describes the pattern, compares it with the sequence and directions, forms a short cause list, changes one meaningful variable, and checks whether the diagnostic information improved.
Patient safety comes before artifact correction.
If the image or situation raises a concern about an implant, foreign body, heating, pain, monitoring device, projectile risk, or other safety issue, pause the examination and follow site policy. Do not continue scanning simply to test an artifact theory.
THE TRACE WORKFLOW
Use the same five questions every time.
What anatomy and diagnostic question must remain visible? Is there any reason to stop for safety?
Is the pattern a ghost, fold, bright-dark edge, signal void, narrow line, broad shade, ringing, distortion, or unusual noise?
Which direction is phase and which is frequency? Does the artifact follow anatomy, an edge, a slice, every image, or only one sequence?
Select the safest approved change most likely to test the leading explanation. Avoid changing several unrelated controls at once.
Compare the result with the original, confirm diagnostic quality, document when required, and seek help if the cause persists.
TURN APPEARANCE INTO A SHORT CAUSE LIST
Let direction, location, and repetition narrow the possibilities.
Check phase direction, patient motion, respiration, pulsation, flow, timing, and suppression.
Check encoded FOV, phase or partition direction, oversampling, positioning, and coil coverage.
Check frequency direction, receiver bandwidth, field strength, fat suppression, and TE.
Check air-tissue interfaces, verified metal, sequence family, TE, bandwidth, voxel size, and shimming.
Check the RF door and environment, coil connection and selection, centering, calibration, and system performance.
Check acceleration factor, active coil elements, calibration, patient movement, FOV, and reconstruction limits.
When safe and appropriate, preserve the original image and note the single change used for the repeat. A controlled comparison teaches more than several simultaneous changes and makes persistent problems easier to communicate.
THE DETECTIVE, NOT THE GUESSER
Every artifact leaves evidence.
A detective does not rearrange the entire scene. They describe what happened, identify where and when it happened, test the strongest explanation, and compare the new evidence.
Remember: Change one thing for one reason, then prove whether it helped.
CLINICAL REASONING PRACTICE
Walk through TRACE before repeating the sequence.
Respiratory ghosts cross the liver in the phase direction. What is a focused first response?
Confirm the phase direction and breath-hold performance, then choose one approved motion-control strategy, such as coaching, timing, respiratory compensation, or a shorter acquisition, while preserving the diagnostic requirement.
A bright zipper line appears on multiple patients and sequences. What does that pattern suggest?
A recurring RF, hardware, or environmental source is more likely than patient anatomy. Check approved immediate causes such as the RF door and unapproved electronics, then document and escalate through the quality-control or service process if it persists.
An accelerated series shows residual wrap after the patient shifted in the coil. What should you investigate?
Check whether calibration still matches the patient and coil position, along with active coil elements, FOV, direction, and acceleration factor.
The artifact improves after one parameter change, but the anatomy becomes too blurry. Is the problem solved?
No. A successful correction must preserve the clinical information. Rebalance the protocol or seek guidance rather than accepting a technically cleaner but nondiagnostic image.
LESSON 36 · CHAPTER 8 COMPLETE
You can recognize common artifacts, test their likely causes, and protect the diagnostic purpose of the exam.Educational references
Troubleshooting steps vary by scanner, coil, sequence, anatomy, patient condition, and facility policy. Use approved protocols, vendor guidance, quality-control procedures, and the appropriate clinical or service escalation path.