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Luc Rotenberg : Digital Breast Tomosynthesis
1. !
DIGITAL BREAST
TOMOSYNTHESIS
(DBT)
Luc Rotenberg, Gregory Lenczner, Henri Ouazan
ISHH – RPO Clinique Hartmann – Ambroise Paré
Neuilly Sur Seine - France
#drrotenberg
dr.rotenberg@radiologieparisouest.com
2. !
As a matter of fact we know:
• Breast screening target is EARLY DIAGNOSIS OF
BREAST CANCER
• In most of the cases Screening reaches the
goal
• almost 10 – 15% of the found late cancers is
originated in regularly screened women
• FFDM is “blind” under some particular
circumstances :
• dense breasts
• dense tissues overlapping lesions
FFDM: SUPERIOR TECHNIQUE, BUT NOT PERFECT
3. !
The challenge of tomosynthesis
An efficient DBT system should accomplish
some basic requirements:
• The total released dose should be lower
than the one released during an FFDM exam
and the closest possible to a 2-D FFDM
projection
• The image quality should be same as the 2-
D, but it has to provide much more clinical
information.
• The exam has to be the shortest possible
(fast scan).
• The scan angle should be large enough to
provide an adequate depth (3-D) resolution.
DOSE 3-D circa = DOSE 2-D
4. !
SCAN ANGLE– PROS & CONS
Wide angle:
+ It provides superior depth resolution: ideal
360° (CT)
- It causes mechanical movement
complexities
- It causes longer scan time
Small angle:
+ More simple design / construction mechanics
+ Shorter scan time
- Lower Depth resolution. Loss of details
perception
15° (±7,5°)
(Hologic Dimensions)
40° 50°
(GE Essential-Siemens
Inspiration)
GIOTTO: 40°
5. !
NUMBER OF PROJECTIONS
PROS & CONS
Large Number:
+ Better reconstruction because more data to
the 3-D algorithm
- Lower S/N per projection because the total
dose is unchanged = Low Image Quality
- Longer scan time
Small Number:
- Less data for the 3-D algorithm
+ Higher S/N per projection = Improved I.Q.
+ Faster scan
• Hologic Dimensions: 15 exp.
• GE Essential: 9 exp (or 15?)
• Siemens Inspiration: 25 exp.
• Giotto Tomo: 13 exp with variable
angles
6. !
-20° +20°
Compression plate
Breast
Digital
detector
— The tube moves
rapidly along an
arc stopping at
each exposure for
a fraction of a
second
— The images are
shown as 1mm
“slices” or more
(slab)
Giotto:13 Projections
STEP & SHOOT
7. !
CONTINUOUS AND STEPPING MOVEMENT:
PROS & CONS
Continuous
+ It is faster = Faster scan time
+ Much simpler mechanics to design and to build
- The exposures during the tube’s movement create anyway a “blurring”
effect so causing the loss of “crispy” contours of the details, especially of the
tiny microcalcifications
Step & Shoot
- More complex mechanics to avoid vibrations due to variations of speed
+ The images made in “frozen” conditions are clear and “crispy”. No detail is
lost.
8. !
PIXEL DIMENSION/ BINNING
Binning: Virtual combination of two or more pixels
of the detector matrix. Usually 4.
+ The total number of pixel decreases 75%
shortening the detector reading, decreasing the
weight of the file and the 3-D recon time
- The spatial resolution decreases dramatically
with loss of details that, if simultaneously the tube
movement is continuous, causes an important decrease
of micro calcifications visibility.
9. !
• Non CT style, but DBT dedicated
• Low number of artifacts
• Better micro calcifications visualization
• Better visualization of the skin line
• Better S/N ratio
• It requires less projections
• The projections can be further apart
ADVANCED 3-D ITERATIVE ALGORITHM
10. !
Pooled BI-RADS–based ROC curves for diagnostic assessment
of conventional diagnostic views and tomosynthesis views
Zuley M L et al. Radiology 2013;266:89-95, Pittsburgh
11. !
DBT
ROC curves for average probability of malignancy as assessed by using conventional
supplemental diagnostic views and tomosynthesis views.
Zuley M L et al. Radiology 2013;266:89-95
12. !
Pooled ROC curves for reader studies 1 and 2 using probability of
malignancy scores; curves represent average ROC performance
for 12 readers in study 1 and 15 in study 2.
Rafferty E A et al.
Radiology 2013;266:104-113
13. !
Assessing Radiologist Performance Using Combined Digital
Mammography and Breast Tomosynthesis Compared with Digital
Mammography Alone: Results of a Multicenter, Multireader Trial
Diagnostic Sensitivity, Specificity, and Positive and Negative Predictive Values
Rafferty E A et al. Radiology 2013;266:104-113, Boston
43. !
US Biopsy & Wire Marking
IDC grade 2, RH+, Her2 -
Large core 16g Biopsy Wire marker
44. !
Dose ?
Full Field Digital Mammogram + Digital Breast Tomosynthesis
FFDM + DBT = dose x 2
Two-dimensional Synthesized Mammograms + DBT
2D SM + DBT = dose x 1
Hologic C-View*
45. !
29/05/2014
FFDM SM
Margarita L. Zuley; Radiology 2014, Ahead of Print.
Comparison of Two-dimensional Synthesized Mammograms versus Original
Digital Mammograms Alone and in Combination with Tomosynthesis Images
123 patients
46. !
Margarita L. Zuley; Radiology Ahead of Print
DOI: 10.1148/radiol.13131530,
2014 by the Radiological Society of North America, Inc.
Comparison of Two-dimensional Synthesized Mammograms versus Original
Digital Mammograms Alone and in Combination with Tomosynthesis Images
Overall ROC curves based on probability of malignancy ratings for individual breasts. FPF = false-positive fraction, TOMO = tomosynthesis, TPF = true-positive fraction.
47. !
Margarita L. Zuley; Radiology Ahead of Print
DOI: 10.1148/radiol.13131530,
2014 by the Radiological Society of North America, Inc.
Comparison of Two-dimensional Synthesized Mammograms versus Original
Digital Mammograms Alone and in Combination with Tomosynthesis Images
Overall breast-based ROC curves for forced BI-RADs ratings. FPF = false-positive finding, TOMO = tomosynthesis, TPF = true-positive finding.
48. !
S The use of SM in lieu of FFDM, whether alone or in combination with
tomosynthesis , does not result in any clinically meaningful differences in
diagnostic accuracy
S Two-dimensional SM can be used as an acceptable replacement for
directly acquired mammograms in tomosynthesis-based evaluations.
S The use of SM reduces radiation dose to patients undergoing
tomosynthesis-based screening mammography.
Margarita L. Zuley; Radiology 2014, Ahead of Print.
Comparison of Two-dimensional Synthesized Mammograms versus Original
Digital Mammograms Alone and in Combination with Tomosynthesis Images
49. !
Two-View Digital Breast Tomosynthesis Screening with Synthetically Reconstructed Projection
Images: Comparison with Digital Breast Tomosynthesis with Full-Field Digital Mammographic
Images
Per Skaane & all. Oslo, Norway. Radiology 2014, Ahead of Print.
S 12 270 women were compared in terms of cancer detection and false-
positive rates with the reconstructed 2D images / FFDM plus DBT
interpretations (2012 january-december)
S Cancer detection rates were 7.8, and 7.7 per 1000 screening
examinations for FFDM plus DBT and reconstructed 2D images plus DBT.
S False-positive scores were 4.6%, and 4.5%, respectively.
S Corresponding reader-adjusted paired comparisons of false-positive scores
revealed no significant differences (ratio = 0.99; 95% confidence interval: 0.88,
1.11; P = .85).
S Conclusion : combination of reconstructed 2D images and DBT
performed comparably to FFDM plus DBT is adequate for routine clinical
use when interpreting screening mammograms.
50. !
Mediolateral oblique images in 61-year-old woman with 12-mm invasive lobular carcinoma in the right breast. Left: FFDM image. Middle: Current
synthesized 2D image. Right: DBT image. The region of interest is magnified for each image. Reader scores for the study were 1 for FFDM, 3 for
FFDM plus DBT, and 4 for synthesized 2D images plus DBT.
Radiology,
Skaane; Andriy I. Bandos; Ellen B. Eben; Ingvild N. Jebsen; Mona Krager; Unni Haakenaasen; Ulrika Ekseth; Mina Izadi; Solveig Hofvind; Randi Gullien; Radiology
Ahead of Print
DOI: 10.1148/radiol.13131391
