design of a wide angle system &...

Tom Handzettel 1

Restricted © Siemens Medical Solutions USA, Inc., 2016 Thomas Klinnert / HC DI XP R&D IC IQ Restricted © Siemens Medical Solutions USA, Inc., 2016

Siemens Digital Breast Tomosynthesis: Design of a wide angle system & Quality Control

Thomas Klinnert, Staff Engineer, August 2016

[email protected]

Page 2 Restricted © Siemens Medical Solutions USA, Inc., 2016 Thomas Klinnert / HC DI XP R&D IC IQ

Mammography is not perfect

• 15-30% of cancers are missed at screening (Bird 1992,

Laming 2000)

• Typical reasons

Dense breast tissue - anatomical noise

Small or no attenutation difference – low or no contrast

Tumor growth pattern – diffuse cancer


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FFDM limitations (where is the suspicious lesion?)

Courtesy of

Malmö University Hospital, Dr. I. Andersson

RMLO RCC

Tom Handzettel 2


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FFDM limitations (where is the suspicious lesion?)

LCC RCC


Digital Breast Tomosynthesis: Why?

• Tomosynthesis reduces tissue overlap! •Tomosynthesis reduces tissue

overlap! •Tomosynthesis reduces

tissue overlap! •Tomosynthesis reduces tissue

overlap!


Digital Breast Tomosynthesis: How?

Multi-parameter problem

Angular range

Number of projections

X-ray spectrum optimization

Dose

Reconstruction method

Tom Handzettel 3


Digital Breast Tomosynthesis: System Design Goal

Good compromise between

Dose

Noise

Depth resolution

Acquisition/compression time

FoV (Field of View)


Digital Breast Tomosynthesis: Prototype

• 2004 first prototype

installed at Duke

University

Proc. SPIE 5745, 529-540, 2005


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First Specimen slices

Courtesy Dr. Baker Duke University Medical Center

Tom Handzettel 4


Digital Breast Tomosynthesis: System Design (angular range)

Large angular range….

Increase depth resolution(z)

Decrease slice thickness (“in focus”)

Reduces “out-of-plane” artifacts

Improves contrast of low-frequency objects

but…

Decreases FOV (stationary detector)

Increase of acquisition/compression


Digital Breast Tomosynthesis: System Design (Ball phantom angular range test)

Optimization of Tomosynthesis Acquisition Parameters: Angular Range and Number of Projections Thomas Mertelmeier et. Al E.A. Krupinski (Ed.): IWDM 2008, LNCS 5116, pp. 220–227, 2008. © Springer-Verlag Berlin Heidelberg 2008


Digital Breast Tomosynthesis: System Design (Number of projections)

More projections …

Decrease streak artifacts (“limited view artifacts”)

but

Reduces signal per projection (at constant total dose)

Increases scan duration and therefore compression time

Tom Handzettel 5


Digital Breast Tomosynthesis: System Design (Clinical result of angular range/projections)

Optimization of Tomosynthesis Acquisition Parameters: Angular

Range and Number of Projections

Thomas Mertelmeier et. Al E.A. Krupinski (Ed.): IWDM 2008, LNCS 5116, pp. 220–227, 2008. © Springer-Verlag Berlin Heidelberg 2008


Digital Breast Tomosynthesis: Development


Digital Breast Tomosynthesis: Development

Tom Handzettel 6


Digital Breast Tomosynthesis Inspiration Clinically approved

50°sweep (continuous scan)

25 projections

<25 seconds (scan time)

W/Rh only

Grid removed

a-Se detector (full resolution

readout)

FBP reconstruction

1mm slice separation


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FFDM limitations reduced with DBT

RMLO


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FFDM limitations reduced with DBT

LCC

Tom Handzettel 7


DBT QUALITY CONTROL (QC)


Digital Breast Tomosynthesis: FDA Rules & Regulations

• Under MQSA, DBT is considered as three different

modalities

• Per DMQS - 8 hours of training is required

http://www.fda.gov/Radiation-

EmittingProducts/MammographyQualityStandardsActandPr

ogram/FacilityCertificationandInspection/ucm447869.htm

• Facility must apply to FDA to have its certificate extended

to include DBT. Also, it must already be an accredited

facility.


Digital Breast Tomosynthesis: QC manual

Current manual:

• VB30 or higher (v1)

http://www.fda.gov/Radiation-EmittingProducts/MammographyQualityStandardsActandProgram/FacilityCertificationandInspection/ucm447869.htm




Tom Handzettel 8


Digital Breast Tomosynthesis: Calibration set


Digital Breast Tomosynthesis: QC Responsibility and Frequency

Only 5 tests for DBT


Digital Breast Tomosynthesis: Test 1, Average Glandular Dose (AGD)

Tom Handzettel 9


Digital Breast Tomosynthesis: Test 2, Geometric accuracy and z- resolution


Digital Breast Tomosynthesis: Test 2, Geometric accuracy and z- resolution (cont’d)


Digital Breast Tomosynthesis: Test 2, Geometric accuracy and z- resolution (cont’d)

Tom Handzettel 10


Digital Breast Tomosynthesis: Test 3, Radiation Field


Digital Breast Tomosynthesis: Test 4, Phantom Image Quality

≥ 4 Fibers

≥ 3 Specks

≥ 3 Masses


Digital Breast Tomosynthesis: Test 5, Artifact Detection

Tom Handzettel 11


System Interface (GUI) tips


Digital Breast Tomosynthesis: System interface (Precursor to DBT QC tests)


Digital Breast Tomosynthesis: System interface (test registration)

Tom Handzettel 12


Digital Breast Tomosynthesis: System interface (procedure/RPG)


Digital Breast Tomosynthesis: System interface (Acquisition settings)


Digital Breast Tomosynthesis: System interface (reconstruct/review)

Tom Handzettel 13


Digital Breast Tomosynthesis: System interface (Closing exam)


Thank you!

design of a wide angle system &...

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