9.1 Technical Factors: kVp, mAs, AEC vs Manual, Target/Filter, Focal Spot, Grid, Mag, Labeling

ARRT Mammography Postprimary

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1 Introduction & Exam Overview

1.1 Current Exam Facts 1.2 Postprimary Eligibility, Structured Education, and Clinical Requirements 1.3 Scoring, Retakes, Fees, and Credential Maintenance 1.4 2025 Content Outline, Domain Weights, and Study Strategy

2 Patient Communication

2.1 Pre-Exam Instructions 2.2 Explaining the Exam, Rapport, and Support 2.3 Patient Education: ACS/ACR Guidelines, BSE, CBE, Dose, and Modalities

3 Results Communication and Breast Cancer Risk

3.1 Process for Receiving Results and Additional Imaging 3.2 Epidemiology and Inherent Risk Factors 3.3 Social Risk Factors, Access, and Hormone Use 3.4 Signs and Symptoms of Breast Disease

4 History, Priors, and Treatment Context

4.1 Medical History, Physical Findings, and Gender Affirmation 4.2 Previous Mammograms 4.3 Surgical, Nonsurgical, and Reconstruction Options

5 Mammography Unit Design

5.1 kVp Range, Tube, Filtration, Window, and Focal Spot 5.2 Compression Paddles, Grids, and System Geometry

6 Digital Acquisition, Display, and Informatics

6.1 FFDM-DR/2D, DBT/3D, and Synthesized Imaging 6.2 Image Receptors and Acquisition vs Interpretation Monitors 6.3 HIS/RIS/EMR, PACS, and CAD

7 Accreditation, MQSA, EQUIP, and Density Reporting

7.1 Accreditation Bodies, FDA/MQSA Personnel, Records, Audits, and Policies 7.2 EQUIP: QA Oversight, Clinical Image Quality, and Corrective Action 7.3 Breast Density Reporting Requirements

8 Quality Control Testing

8.1 Mammographer QC: Phantom Image, Compression Thickness, Visual Checklist 8.2 Mammographer QC: Monitors, Repeat Analysis, Viewing Conditions, Compression Force, Detector Calibration 8.3 Physicist Tests: MEE, Collimation, Spatial Resolution/MTF, SNR/CNR, AEC, AGD, kVp, HVL 8.4 Physicist Tests: Artifacts, Phantom Quality, Illuminance, Tech QC Program Review, Compression Application/Paddle Alignment, Workstation QC

9 Technique and Image Evaluation

9.1 Technical Factors: kVp, mAs, AEC vs Manual, Target/Filter, Focal Spot, Grid, Mag, Labeling 9.2 EQUIP Image-Quality Criteria 9.3 Patient-Related Artifacts

10 Localization and Anatomy

10.1 Clock Position, Quadrants, and Triangulation 10.2 External Anatomy 10.3 Internal Anatomy: Fascia, Glandular Tissue, and the TDLU 10.4 Cooper Ligaments, Pectoral Muscle, Vascular/Lymphatic Systems, and Cytology

11 BI-RADS Lexicon

11.1 Architectural Distortion, Asymmetry, and Mass Features 11.2 Calcification Morphology and Distribution 11.3 Assessment Categories, Breast Density, and Recommendations

12 Breast Pathology

12.1 Benign Pathology and Mammographic Appearance 12.2 Lesions with Upgrade Potential 12.3 DCIS, IDC, and Invasive Lobular Carcinoma 12.4 Inflammatory Carcinoma, Paget Disease, Sarcoma, Lymphoma, and Metastases

13 Standard Screening Views

13.1 Craniocaudal (CC) Positioning 13.2 Mediolateral Oblique (MLO) Positioning

14 Additional Views I

14.1 Mediolateral (ML) and Lateromedial (LM) 14.2 XCCL, XCCM, Cleavage (CV), and Axillary Tail (AT) 14.3 Tangential (TAN) and Rolled Views (RL, RM, RS, RI)

15 Additional Views II

15.1 Implant Displaced (ID), Nipple in Profile, and Anterior Compression 15.2 Spot Compression and Magnification

16 Patient Variance

16.1 Chest Wall Variations, Kyphosis/Lordosis, Protruding Abdomen, and Extreme Breast Size 16.2 Irradiated Breast, Reduction Mammoplasty, and Postsurgical Breast 16.3 Male Patients and Lactating Breast 16.4 Breast Augmentation and Implanted Devices

17 Imaging Examinations

17.1 Screening vs Diagnostic Mammography 17.2 Breast Ultrasound and Breast MRI

18 Interventional Procedures

18.1 History, Consent, Time-Out, Setup, and Postprocedure Instructions 18.2 Stereotactic and Ultrasound-Guided Biopsy 18.3 Needle Localization, Specimen Imaging, and Clip Placement 18.4 Handling and Disposing of Biohazardous Materials

9.1 Technical Factors: kVp, mAs, AEC vs Manual, Target/Filter, Focal Spot, Grid, Mag, Labeling

Key Takeaways Explain This Topic AI

AEC is the default for contact views when breast tissue covers the sensor; switch to manual for implant-in-place views, specimens, very thin breasts, and hardware that overlies the AEC cell.

Geometric magnification uses a small focal spot, grid out, and at least one MQSA magnification value between 1.4 and 2.0; contact screening uses the large spot with the grid in.

21 CFR 900.12(c)(5) requires patient name plus a second identifier, date, view and laterality near the axilla, facility city/State/ZIP, technologist ID, cassette/screen ID, and unit ID if more than one unit is present.

Compressed thickness is an AEC input: a wrong paddle thickness reading selects the wrong kVp and target/filter even when the breast looks well positioned.

Target/filter is usually auto-selected from thickness; override toward a softer beam for pancake or specimen contrast and a harder beam when backup time or motion is the risk.

Last updated: August 2026

Technique is the last controllable step before a mammogram becomes a medical record. On the ARRT Mammography examination (content specifications implemented September 1, 2025), Image Production treats kVp , mAs , automatic versus manual exposure, target/filter , focal spot , grid , magnification , and labeling as one working set. At the acquisition workstation (AWS), those choices decide whether the interpreting physician receives an image that can meet Enhancing Quality Using the Inspection Program ( EQUIP ) clinical-image criteria.

kVp: Subject Contrast Versus Penetration

Mammography uses a low peak kilovoltage (kVp) beam so photoelectric absorption can separate fat from fibroglandular tissue. Clinical settings cluster in the mid-20s to low-30s kVp. Generators can go wider; the exam tests the logic, not a vendor’s full scale.

Lower kVp raises subject contrast and absorbed dose and lengthens exposure time.

Higher kVp improves penetration of thick or dense breasts, shortens time (less motion), and lowers contrast.

On full-field digital mammography ( FFDM ) and digital breast tomosynthesis ( DBT ), display windowing can recover some grayscale, so a slightly harder beam is common. That does not make kVp irrelevant. Too hard, and dense tissue stays gray-on-gray after processing. Too soft, and automatic exposure control ( AEC ) runs long, the backup limit may trip, and motion unsharpness appears.

mAs: Quantity, Noise, and Time

Milliampere-seconds (mAs) set photon quantity. On film, mAs mainly changed optical density. On digital detectors, underexposure shows as quantum noise (grain) rather than a “light” image, and overexposure can still look acceptable after processing while delivering unnecessary dose.

After an AEC exposure, 21 CFR 900.12 requires the system to display the actual kVp and mAs used. Compare that mAs with what you expect for the compressed thickness: a 4 cm fatty breast that took a huge mAs, or a 7 cm dense breast that took almost none, is a technique problem even if the processed image looks pretty.

Long mAs (small focal spot, thick breast, low kVp, grid in) is the motion trap. If time is the problem, raise kVp or select a harder target/filter rather than stacking more mAs onto a moving patient.

Automatic Exposure Control

AEC (sometimes called an automatic exposure device) measures radiation reaching the detector and terminates the exposure. On most digital units it also selects kVp and target/filter so glandular tissue is adequately exposed. Two operator jobs remain:

Compressed thickness must be true. The paddle reports thickness into the AEC algorithm. A paddle that is not fully down, a thickness calibration that is off, or a flex paddle that reports the wrong height will pick the wrong spectrum.

The sensing region must sit under the tissue of interest , not under implant, hardware, open air, or a thin fatty tail. On systems with selectable AEC positions, the active cell is marked on the paddle; put dense tissue over it.

AEC is the default for contact screening and for most diagnostic views of intact breast tissue.

When Manual Exposure Is Required

AEC is inappropriate when the sensor cannot “see” a representative thickness of breast tissue. That is the exam distinction—not a preference for old-school charts.

Clinical situation AEC vs manual Paddle / setup Magnification / grid / focal spot

Standard screening CC/MLO, tissue covers sensor AEC Full-field paddle matched to breast size Contact; grid in ; large (contact) focal spot

Implant-in-place (implant included) Manual — implant over the sensor overexposes parenchyma Implant or full paddle; do not over-compress the implant Contact; grid in; large focal spot

Implant-displaced (Eklund) ID views AEC if displaced tissue covers the sensor; manual if it does not ID technique; implant pulled back Contact; grid in

Very thin compressed breast (often under about 2 cm, “pancake”) Often manual ; AEC may miss and contrast collapses Small paddle; confirm the thickness reading Contact; grid in; consider a softer beam for contrast

Very thick or mosaic (tiled) breasts AEC if each tile covers the sensor; manual if a tile is mostly air or AEC hits backup Large paddle or tiled exposures Contact; grid in; harder beam if the backup limit trips

Surgical or core specimen radiograph Manual — thin object, no living breast for the sensor to measure Spot paddle or specimen holder; light immobilization only Often mag with small focal spot and grid out

Pacemaker, port, or hardware over the sensor Manual , or reposition so hardware is off the sensor, then AEC Include as much breast as possible without forcing hardware into the cell Contact; grid in

Geometric magnification of calcifications Unit mag AEC if tissue covers the sensor; manual for tiny specimens Spot paddle; mag platform Mag 1.4–2.0 ; small focal spot ; grid out (air gap)

Do not memorize one universal manual mAs. Start from a reasoned value for that thickness, then judge noise and contrast on the AWS.

Compression Thickness as a Technique Input

Thickness is not only a positioning goal. Digital AEC uses compressed breast thickness (and often a brief prepulse for composition) to choose kVp, filter, and mAs. If quality-control thickness accuracy is off, every automatic technique is biased. At the AWS, glance at the displayed thickness before you expose: a 3 cm-looking breast reported as 7 cm will get a beam that is too hard; the reverse looks noisy.

Adequate compression still matters for scatter, dose, overlap, and motion—those are image-quality criteria in the next section. Here the exam point is simpler: wrong thickness in → wrong technique out .

Target and Filter Selection

Classic screen-film spectra used molybdenum (Mo) or rhodium (Rh) targets with Mo or Rh filters. Characteristic peaks (Mo near 17–20 keV; Rh a few keV higher) and K-edge filtration shaped a narrow, high-contrast beam.

Mo/Mo: highest contrast, best for thinner or fattier breasts; higher dose.

Mo/Rh or Rh/Rh: more penetrating for thicker or denser tissue.

Tungsten (W) with Rh, silver (Ag), or aluminum (Al) filters: common on FFDM/DBT; better penetration, lower dose, slightly less inherent subject contrast—which digital processing can partly restore.

Most digital units auto-select target/filter from thickness. You still need to know when to override: a very thin specimen or pancake breast may need the softest available combination for contrast; a thick, dense, or implant-in-place view needs a harder beam so the exposure finishes before motion. 21 CFR 900.12 requires the selected target to be indicated before exposure when more than one target is provided.

Focal Spot: Contact Versus Magnification

Mammography tubes provide a large (contact) focal spot—commonly on the order of 0.3 mm—and a small spot—commonly on the order of 0.1 mm—for geometric magnification. The system must indicate which spot is selected before exposure.

Contact (grid-in) screening and most diagnostic views: large spot. Higher tube current, shorter time, less motion.

Magnification: small spot. Geometric unsharpness grows with focal-spot size and object-to-image distance; the small spot keeps calcifications sharp on the mag platform.

Using the large spot on a mag stand is a classic sharpness fail. Using the small spot for routine contact views needlessly lengthens time.

Grids In Versus Out

A moving grid reduces scatter in contact geometry and is the default for craniocaudal ( CC ) and mediolateral oblique ( MLO ) views. MQSA requires magnification systems to operate with the grid removed . The mag air gap lets scatter miss the detector, so the grid’s contrast benefit is replaced and you avoid the extra time a grid would add to an already long small-spot exposure.

• Geometry Grid Why
• Contact (breast on the receptor) In Scatter from the full breast would wash out contrast

Magnification (breast on mag platform) Out Air gap replaces the grid; a grid would prolong time and raise motion risk

If grid lines appear, or a contact screening view was acquired with the grid out, that is a technique error—not a patient artifact.

Magnification Technique

Under 21 CFR 900.12, units used for noninterventional problem-solving must offer radiographic magnification, with at least one factor between 1.4 and 2.0 . True geometric magnification is not the same as zooming a digital contact image.

Mag technique as a bundle:

• Mag platform (increased object-to-image distance)
• Small focal spot
• Grid out
• Spot compression when the indication is calcifications (thinner tissue, less scatter, shorter time)

Collimate to the area of interest for calcifications (less scatter); do not collimate so tightly on a mass work-up that landmarks disappear

Expect longer exposure times. Coach stillness. If the image is blurry, think motion first, then whether the large spot was left selected.

MQSA Image Identification (Labeling)

Each mammographic image must carry the following information in a permanent, legible, and unambiguous way, placed so as not to obscure anatomic structures ( 21 CFR 900.12(c)(5) ):

Name of the patient and an additional patient identifier (medical record number is typical; date of birth is a weaker unique ID)

• Date of the examination
• View and laterality using accreditation-body standardized codes, placed near the axilla
• Facility name and location — at minimum city, State, and ZIP code
• Technologist identification

Cassette/screen identification (the screen-film cassette ID; on FFDM this is the detector/cassette identifier in the DICOM header)

Mammography unit identification if the facility has more than one unit

Those are the FDA fields. Do not treat kVp, mAs, filter, compression force, or thickness as MQSA-required labels. Those readouts are useful and often displayed; they are not the legal ID list. Wrong laterality, a missing second identifier, or view codes not near the axilla are labeling fails you correct before the study is released—not findings to “interpret around.”

AWS Habit Before You Send

Confirm AEC versus manual matched the clinical table, displayed thickness is plausible, focal spot and grid match contact versus mag, and every required ID field is present. That is technique evaluation, and it is what EQUIP later scores as examination identification plus exposure, contrast, and sharpness.