Breast radiology - all topics

Question 1

BI-RADS rating & descriptor?

Answer 1

• BI-RADS 2: rim calcification (oil cyst)

Question 2

Name the artifact.

Answer 2

• Chin artifact on MLO.

Question 3

1. Name the artifact?
2. How do you correct it?

Answer 3

1. Bad pixel: only present on digital detectors.
2. Recalibrate the detector: it will subtract out bad pixels to create a uniform field.
   
   • If the artifact persists after full-field calibration then the detector needs to be replaced.

Question 4

Which artifact is shown here, in this study to evaluate for silicone breast implant rupture?

Answer 4

• Silicone saturation artifact.
  
  • Occurs when silicone is selected for saturation instead of fat.
  • Causes the silicone to appear dark, so exam is non-diagnostic.
  • Silicone should appear white in this sequence (inversion recovery w/water saturation).

Question 5

Name the artifact.

Answer 5

Susceptibility.

• B/c of metal on pt’s skin.
• Artifacts are warped images, signal voids or flares.

Question 6

1. Which artifact is this?
2. How can this be reduced?

Answer 6

1. Inhomogenous fat saturation artifact.
   
   • Happens when there is an unexpected variation in the magnetic field.
2. Shim the magnet frequently (that is, optimize field homogeneity), which can sometimes correct inhomogeneous fat sat artifact.

Question 7

1. Name the artifact.
2. In which encoding direction does patient motion propagate?

Answer 7

1. Patient motion/ghosting (the pt coughed during the exam).
2. Phase-encoding, regardless of direction of motion.
   
   • Brighter moving tissues will “ghost” in the phase-encoding direction.

Question 8

• Which artifact is present in this axial T1 post-gad fat-sat image?

Answer 8

• Susceptibility artifact: focal signal intensity void w/a partially surrounding area of high signal intensity and image distortion in the sternum.
  
  • This is from sternotomy wires.

Question 9

Name the artifact.

Answer 9

• Readout failure.
  
  • The line artifact is caused by software processing failure.
  • This can correct itself or a new detector readout sequence file can be installed.

Question 10

1. Name the artifact.
2. When does this occur?
3. In what direction does this occur?
4. How do you correct this?

Answer 10

1. Aliasing/wrap-around.
2. When not all of the signal-producing tissue is within the FoV:
   
   • the signal from the excited tissue outside the FoV becomes superimposed on the structures within the FoV through misregistration during Fourier transform reconstruction.
3. In the phase encoding direction.
4. Increase the FoV.
   
   • Or use pre-saturation bands on areas outside the FoV.
   • Or use anti-aliasing software.
   • Switch the phase & frequency coding directions.
   • Use a surface coil to reduce the signal outside the area of interest.

Question 11

1. Name the artifact.
2. When does this occur?

Answer 11

1. Detector interface line.
2. From a selenium-based detector, when there is a slight difference in calibration of 2 halves of the detector & relatively high exposure for imaging very dense breast tissue.

Question 12

1. Name the artifact.
2. When/how does this occur?
3. How do you fix it?

Answer 12

1. Zebra artifact: black & white banding.
2. Occurs when signal-producing tissue outside of the FoV wraps into the selected FoV & when poor magnet shimming leads to a phase shift b/w the tissue within the selected FoV & tissue outside it. It’s a type of phase interference.
   
   • Black bands: signals from the 2 regions are out of phase & cancel each other out.
   • White bands: signals are in phase & combine to form a white band.
3. Enlarge the FoV & apply phase oversampling.
   
   1. Magnet reshimming can also improve this.

Question 13

DDx unilateral skin thickening

Answer 13

• Unilateral edema
• Mastitis
• Post-procedural
• Abscess
• Inflammatory carcinoma
• Underlying malignancy

Question 14

Dx? Reproductive-aged female receiving hormone Tx.

Answer 14

PASH (pseudoangiomatous stromal hyperplasia): large (4-6cm), solid, oval mass w/well-defined borders & no calcs.

• Not in males.
• typically, reproductive-aged females receiving hormone Tx.
• ZERO malignant potential.
• F/u in 12 mos is the typical recommendation.
• However, if it is enlarging, if the pt is concerned or if Ix features are atypical, wide local excision.

Question 15

Dx, BR score?

Answer 15

Sebaceous or epidermal inclusion cyst, BR-2: superficial, oval, complicated cystic mass w/posterior acoustic enhancement w/a hypoechoic structure extending from the mass to the skin.

• Clinically & on imaging, these 2 entities are indistinguishable.
• Require no Tx & are benign.

Question 16

What does stroke margin refer to?

Answer 16

Length of the post-fire needle tip position to the detector/breast support.

• Positive stroke margin means there is adequate margin to safely fire the core Bx needle.