1. Pitfalls in breast MRI :
How to deal between
Sensitivity and Specifcity ?
P. Taourel, E. Pages

2. Breast MRI : a weak specificity
• Studies comparing MRI and MG
– Staging of brast cancer : Spe = 70%
close to Spe of MG
– High risk women : Spe = 90 %
• Why this feeling of low specificity
– enhancement ≠ cancer
– Lack of experience
– Difficulty of biopsy
C Kuhl Radiology 2007

3. Breast MRI : is it perfectly sensitive ?
• The sensitivity of an exam depends of the gold standard
> 95 % in most of the studies
≈ 75 % in screening studies
= 85 % in the stidy with gold standard = pathologic analysis
of mastectomy
• MRI Sensitivity > Sensitivity of other imaging modalities

4. Causes of avoidable F+
• Artefacts
• Normal structures
• Benign tumors

7. Causes of avoidable F+
• Artefacts
• Normal structures
• Benign tumors

10. Backround enhancement
• Bilateral and
symmetric
• Hormonal and
therapeutic context
• Age of the patient
• The backround
enhancement must be
graded

11. Genetic risks, BRCA 1
40 years old

12. Genetic risks
40 years old
Right mass : fibroadenoma
ovariectomy

14. To analyze / classification BIRADS
• Mass
– 3D
– Cancer, FA, papilloma, fat necrosis, sclerosing
adenosis, lymph node, some atypical form of benign
lesions
– Key features for Benign:
•
•
•
•
•
•
Smooth outline
Regular form
Homogeneous enhancement (value if big)
Hyper T2
Fat content
Weak enhancement and no wash-out

17. 2009
2010

19. Value of hyper T2 if homogeneous

20. Rim must be analyzed according to the
content and the regular pattern

21. To analyze / BIRADS classification
• Non mass enhancement
– Neither mass nor focus
– Benign mass, young patient, inflammation,
DCIS, ILC
– Key features for enhancement :
• Bilateral and symmetric
• Cysts ++
• Negative findings

23. To analyze / classification BIRADS
• Focus
– < 5 mm
– Very low rate of malignancy
– Key features for benign (no F.U = BIRADS 2)
• Multiple
• No wash-out
• Clinical context

24. F• Lack of enhancement
• Not seen
– Backround enhancement, artefact
– small
– Tricky area
• Misinterpretation
• Mismanagement

25. Causes of False negative
• Retrospective review of 60 pairs of breast
cancer
• 47% of « errors »
– 10% = misdiagnosis
– 25% = misinterpretation
– 12% = mismanagement
Pages Radiology 2012

26. Lack of enhancement
• DCIS
• Small invasive cancer
• Some pathologic pattern:
– Inflammatory cancer
– Invasive lobular carcinoma

153. F• Lack of enhancement
• Not seen
– Backround enhancement, artefact
– small
– Tricky area
• Misinterpretation
• Mismanagement

156. Oct 2004
Mai 2005

175. 1an plus tard

192. F• Lack of enhancement
• Not seen
– Backround enhancement, artefact
– small
– Tricky area
• Misinterpretation
• Mismanagement

195. 2007
2008
Benign morphology’’ : oval form, smooth
outlines, non enhanced septas

196. Forme ronde
Phénotype triple-négatif
RP-
RE-
HER2 -

198. Benign/malignant association

205. 1 year later

211. 2003
2005
2006

212. Be careful with kinetic, particularly in
menopausal patients
2
3
OR not to have
malignant curve
in menopausal 2
patients :
2.94 : initial rise
2.38 : washout 1
I Millet
Radiology dec
2013
Progressive
Plateau
ROI > 3 pixels
Région la plus
suspecte
Lavage
Temps
(min)

213. F• Lack of enhancement
• Not seen
– Backround enhancement, artefact
– small
– Tricky area
• Misinterpretation
• Mismanagement

215. • Retrocystic enhancement

218. Importance du clip

219. How to avoid F+ and F- ?
1.
2.
3.
4.
To recognize the pseudo-enhancement
To negative normal structure : bilateral foci,
punctuate enhancement, lymph nodes
6 month FU
Interpretation according to clinical context and
personal status
- focus/BIRADS
- enhancement/menopausal status
5.
6.
Be careful with stability (morphology +++)
Be careful with autosatisfaction : FU of benign
results in biopsy performed on 2d look US