9.3 Patient-Related Artifacts

The 2025 ARRT Mammography content specifications added patient-related artifacts under technique and image evaluation. Equipment ghosts and software processing lines are quality-control problems. This section is what the patient brings into the field—and whether that appearance is a technical repeat or something the radiologist must interpret. Patient-care chapters already cover wiping deodorant before the first exposure. Here the question is: what does it look like on the image, and do you repeat?

Motion

Motion is the most common patient-related artifact on FFDM. Appearance: loss of sharp trabeculae, a smeared skin line, calcifications that look larger and less distinct than on the other view. On DBT, blur is often clearer on projection frames than on reconstructed slices. On contrast-enhanced mammography, motion between low- and high-energy frames can produce banding.

If blur overlays parenchyma, repeat with more effective immobilization and a shorter exposure. Do not send a smeared MLO because “she was shaking.” If the patient cannot hold still after a good-faith attempt, document the limitation and still provide the sharpest achievable image. Motion is an EQUIP sharpness fail and a patient-related artifact at the same time; the action is still a better-immobilized retake when cooperation is possible.

Clothing and External Objects

Buttons, embroidery, wrinkles in a gown, jewelry, and eyeglasses are high-attenuation or textured shadows. Glasses commonly clip the superior CC or anterior MLO. Hair hanging over the superior breast makes streaky, wavy lucent or dense lines that can mimic architectural distortion.

Remove the object, smooth hair off the field, and repeat. These are never “leave for the radiologist” findings when they overlie breast tissue. A necklace under the gown is not a calcification cluster.

Anatomy: Skin Folds and Other Body Parts

Skin folds appear as curvilinear lucent lines or dark air-gap bands where skin is doubled. A fold across the posterior breast can hide a mass. Other body parts—chin on the superior CC, abdomen or opposite breast on the MLO, a hand or shoulder in the axillary tail—add extra density and can fool AEC.

If the fold or extra part overlays tissue you need, lift, taut the skin, and repeat. A tiny fold in far axillary skin that does not cover parenchyma may be documented rather than endlessly repeated; that is judgment, not laziness. Geriatric loose skin folds easily—that is technique, not “the patient failed.”

Deodorant, Antiperspirant, and Powder

Patients should arrive without deodorant; that instruction lives in patient care. On the image, talc and antiperspirant leave high-density, specklike particles, typically in the axilla and skin folds, that mimic microcalcifications.

If you see axillary specks that sit on the skin line or in a fold, wipe the skin and repeat. Do not annotate “deodorant?” and send the study as if the radiologist should guess. If specks persist after cleaning and sit in a pattern of dermal calcifications (lucent centers, known skin calcifications), leave that differential for the IP—you already did the technical step.

Implanted Devices

Pacemakers and infusion ports overlay the MLO more often than the CC. They are dense, structured, and often have a processing halo on digital images. They can sit on the AEC cell and blow the exposure.

• Reposition to include as much breast as possible without dragging the generator into the middle of the glandular tissue if the device can be avoided.
• Switch to manual if the device remains over the sensor.
• Do not repeat in order to make the device disappear. Document its presence. The radiologist interprets tissue around hardware; you are responsible for exposure and for not excluding posterior breast while “avoiding” the device.

Tissue expanders, sternal wires, and injection-related foreign material follow the same rule: they are inside the patient, not dirt on the skin.

Intramammary Lymph Nodes Versus Artifact

A prominent intramammary lymph node (IMLN) is usually an upper-outer-quadrant, reniform, circumscribed density with a fatty hilum, often projected over the pectoral margin on the MLO. It is not an artifact. Do not wipe the skin, do not repeat to “get rid of the mass,” and do not mark it as a mole unless there is a corresponding skin lesion.

If the density is not circumscribed, has no hilum, is high density, or is new compared with priors, it is a finding—still not a technical repeat. Leave it for the radiologist.

Tattoos, seborrheic keratoses, and moles can mimic masses or calcifications; those you mark and, if they look like surface specks, correlate with the skin.

Appearance → Cause → Action

If you can take the cause off the patient or out of the field in the room, and it hides or mimics disease, it is a technical repeat. If the cause is inside the patient (node, implant, pacemaker) or a documented positioning limit, do not manufacture a repeat that cannot change the physics. The radiologist owns interpretation; you own whether the image is a fair test of the tissue.