Breast MR/procedures Flashcards
Indications for breast MRI (6)
Implant evaluation
axillary mets w/ unknown primary
extent of disease
assessing response to therapy
diagnostic delemma
high risk screening
- Who gets a screening MR?
- Which risk model do you use?
- People w/ lifetime risk >15-25%
People who got 20Gy of radiation to chest
- Use Tyrer Cuzickrisk model because it includes family history. The “Gail” risk model does not.
6 sequences that you use for breast MR
T2 w/ FS
T1 Pre w/ FS
T1 Post
Saggital
Subtracted
MIP
- Flaring artifact
- How to fix it
Non-uniform fat suppression when breast tissue is very close to coil elements.
This artifact is not related to fat suppression.
You have to put padding b/w the breast tissue and coil elements.
Background parenchymal enhancement
- When in cycle should you scan in order to minimize BPE
- what other factors effect it?
- Days 7-14
- Hormone therapy (should be stopped)
Serms decrease BPE
Tamoxifen rebound results in increased BPE
-lumpectomy and radiation
Does nipple enhance on Breast MR?
Yes. Enhancement is normal
Defninitition of “foci” in MR
Dot of enhancement (<5mm). Too small to characterize.
If there are many foci, then it is probably BPE
- What does it mean if mass/foci in MR is T2 bright?
- What is the one exception?
- Benign things that enhance (name 3)
- T2 bright = BR2
- Mucinous (colloid) cancer
- fibroadenoma, Papilloma, Lymph nodes
Appearance of firoadenoma on MR
Circumscribed round/oval mass
Variable on T2
On post-contrast, it can enhance, and have non-enhancing septations
If a lesion is not T2 bright, then what do you look at?
- Mass margin should be evaluated on the first post-contrast series. What border feature is most predictive of malignancy?
- Look at morphology, then kinetics
- Spiculated
- Non-mass like enhancement is classic imaging for what?
- It is described by distribution. The distribution is its most predictive feature. Which distributions are bad?
- DCIS is Classic, but it can also represent IDC
- Segmental is worst distribution. Linear, and focal distribution is bad.
BiRADS - MR lexicon
- Shape - 3
- Margins - 3
- Enchancement - 4
- Round, oval, irregular
- Circumscribed, spiculated, irregular
- Homogenous, heterogenous, rim, Dark internal septations.
BIrads - MR lexicon for NME
- Disribution - 6
- Internal enhancement - 4 - (which is the wort kind)
- Focal, segmental, linear, regional, multiple regions, diffuse
- Homogenous, heterogenous, clumped, clustered ring
Clustered ring is the worst kind.
2 types of breast implants. 2 locations.
- Saline and silicone (can’t see through silicone on Mammo)
- For Silicone, you body will form a fibrous capsule around implant. - subglandular/retromammary, subpectoral/retropectoral
- Saline -types of ruptures
- Types of silicone ruptures
appearance on Mammo, u/s and MRI
*if you see silicone in a lymph node, you need to recommend MRI to evaluate for extracapsular rupture.
- Saline - no capsule (no such thing as ‘intracapsular rupture”)
- Silicone: both intra and extra capsular rupture.
mammo: You can’t see intra on mammogram.
u/s: extracapsular creates snowstorm appearance
intracapsular creates ‘step ladder’ appearance.
MRI: intracapsular has linguine sign
What type of mammo views do you need to get with implants
4 views of each breast. CC, MLO, and implant displaced CC and MLO.
When can you BR-0 an MR study?
Never.
Unless the study was technically limited.
Can you BR3 a solitary focus on MRI
If it is solitary focus with persistent kinetics on baseline exam, you can give it a BR3
Describe Cowden Syndrome (4 things)
Bowel hamartoma, follicular thyroid cancer, Lhermitte Duclos, breast cancer
- u/s biopsy - how to position
- What should be needle projectory?
- roll breast away from lesion (thin the tissue)
Raise ipsilateral arm.
- parallel to chest wall
- For ultrasound biopsy of a ‘disapearing lesion,’ which part of the lesion swould you biopsy?
- If there are 2 lesions and 1 of them is obvious/large and the other is less obvious, which do you biopsy first?
- biopsy the posterior part first, becase then you can still see the anterior part.
- Biopsy the one you see worse first. This is because then if things get distorted, you can probably still see the big one.
Situations when a stereo biopsy is difficult
Thin breast (<2-3cm compressed thickness)
Lesions too close to skin
subareolar lesions
posterior lesions
How do you calculate depth when doing a stereo biopsy?
Get a +15 degree and -15 degree images. Then the compute will calculate depth (z axis)
What is stroke margin?
What do you want, a positive or negative stroke margin?
Distance between when where the needle is supposed to end after the throw, and the skin on the opposite side
Positive stroke margin: You still have space between needle throw and skin
Negative stroke margin (bad): your needle through will puncture skin
Stereo targeting error: how can you tell X vs. Y vs. Z axis error?
on X axis, images will project with different relationship to the lesion (ex. one projects over the lesions, when the other is off the lesion)
On Y axis, both images will be either superior or inferior to the lesion
On Z axis, both images will either be not deep enough, or too deep
What is management of high risk lesions?
Surgical excision
