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A new method for QA/QC of mammo and tomo devices. Hugo de las Heras Gala , Felix Schöfer, Britta Tiller (QUART GmbH, Germany ), Margarita Chevalier del Río (Universidad Complutense de Madrid, Spain ), Georg Zwettler and Friedrich Semturs
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A new method for QA/QC of mammo and tomo devices Hugo de las Heras Gala, Felix Schöfer, Britta Tiller (QUART GmbH, Germany), Margarita Chevalier del Río (Universidad Complutense de Madrid, Spain), Georg Zwettler and Friedrich Semturs (Medizinische Universität Wien, Austria) IRPA 13, Glasgow (Scotland), 13-18 May 2012
Thephantomis a 46 mm-thick PMMA block (IEC) witha stepwedgesimulating0-60 mm of PMMA PAS insert 180 mm Br 240 mm 6mm 20 mm 20 mm 0.1, 0.2, 0.3 mm Aluminium Titanium strips (12.5 m)
TheQUART phantomcontainsobjectsforalltestsincluded in theEuropeanguidelines(EPQC) Spheresforphantomalignment and determination of artefact spread function Edgeobjectfor MTF determination 12-step wedge tomeasure CNR Low and medium contrastobjects 46 mm step Slot for detector Titaniumbackground (alsofor tomosynthesis) A differentgroup of Landoltringsin eachstep (alsofor tomosynthesis)
X-ray transmission through microcalcifications and through titanium is very similar (Data from ICRU 44 and NIST)
QUART phantom and dosimeterwereusedtomeasureimagequalityandentrance skin air kerma Dosimeter Stepwedge
The evaluation provides a score as a function of the PMMA thickness for the Landolt rings (Oneimageforeach curve)
The evaluation provides a score as a function of the PMMA thickness also for the contrast-to-noise ratio (Oneimageforeach curve)
Acceptable and achievablethresholds can be set compliant with the European Protocol for QC
In summary, the QUART method is an efficientsolution for routineandacceptance tests • The QUART phantomiscompliantwithEuropeanProtocol (EPQC) • Visual contrast-detail test usingtitanium (15 minutes) • Automaticevaluation of CNR and MTF (5 minutes) • Sensitivityequivalenttoestablished test(CDMAM) • In addition, thestepwedge • considersvariations in thickness and tissuedensitywithinthebreast • offerstomosynthesisevaluation Questionsorcomments? Hugo.Heras@daad-alumni.de & Poster PO7.173
Back-up slides
Theentrance skin air kermameasurementsshowagreementwithrespecttotheconsolereadings
Acceptable and achievablethresholds can be set also for the automatic evaluation of CNR
This talk presents an efficient method for quality control and results from an example routine test Visual and automatic evaluation Results and comparisons Phantom description