Needle crystal detector technology in mammography further dose reduction and clinical image quality with

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1 Needle crystal detector technology in mammography further dose reduction and clinical image quality with different beam qualities (W/Rh vs. Mo/Rh) Poster No.: C-1461 Congress: ECR 2013 Type: Scientific Exhibit Authors: P. Peloschek, E. Kalinowski, G. Langs, G. Zwettler, F. Semturs; Vienna/AT Keywords: Breast, Radiation physics, Mammography, Plain radiographic studies, Digital radiography, Diagnostic procedure DOI: /ecr2013/C-1461 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 11

2 Purpose To compare diagnostic image quality of CR needle crystal technology used in mammography acquired with anode/filter combination of Tungsten(W)/Rhodium versus Molybdenum/Rhodium. This showed equivalent technical image quality (EUREF, CDMAM) with further dose reduction of 15-20% in earlier studies. Hence compared with traditional CR storage phosphor plates, CR needle crystal technology used in mammography claims to allow for better image quality using a lower dose (i.e. total dose reduction of 40 to 50% with Tungsten(W)/Rhodium) without loss of diagnostic image quality. Methods and Materials 100 subsequent patients were included, 6 had to be excluded from comparative analysis due to severe unilateral postsurgical distortion. All patients obtained 4 mammograms performed with a Siemens Mammomat and the new Agfa DX-M needle-based imaging plate system (NIP). Randomly one side was performed with W/Rh, and one side performed with Mo/Rh. Compression thickness was recorded digitally. Mammograms with a left to right compression thickness difference of more than 10mm were excluded. All mammograms were read twice by two experienced radiologists to score the detectability of any difference between the right and left mammogram. Reading was performed on 5MP monitors (EIZO GX 530) and 1:1 image presentation on a dedicated multimodality workstation (MacPro, 2x ATI Radeon HD GB, OsirixPro 64bit, AYCAN), radiologists were blinded to imaging parameters. Image quality was rated on a relative scale with respect to the appearance of parenchyma, fat, cutis, benign lesions and calcifications. No malignancy was detected within this group. Images for this section: Page 2 of 11

3 Table 1: ACR breast density of the patients included. Page 3 of 11

4 Table 2: Digitally measured breast thickness of the patients included. Table 3: Overall diagnostic image quality preference versus ACR breast density. Page 4 of 11

5 Table 4: Overall diagnostic image quality preference versus measured breast compression thickness Page 5 of 11

6 Results Breast tissue density was ACR level 1 in 15 of 94 (16%), 2 in 47 of 94 (50%), 3 in 23 of 94 (24%), and 4 in 9 of 94 (10%) cases. However, no clinically relevant difference of image quality was detected. In 11 of 94 (12%) cases a difference of image appearance between the right and left mammogram was given. The subjective interpretation of image quality favored W/Rh in 3, and Mo/Rh in 8 cases, these slight differences can be eliminated by the taste settings of the Musica² image processing. Compression thickness differences less than 11mm did not influence image quality. Images for this section: Table 5: Average glandular dose achieved, compared to breast compression thickness. Page 6 of 11

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8 Fig. 1: For illustration: Pat A, RCC mammogramm with Mo/Mo filter and 36mm breast thickness. AGD was 9% lower as compared to contralateral W/Rh filtered mammogram (Fig.2.) Fig. 3: For illustration: Pat B, R oblique mammogram with W/Rh filter and 47 mm breast thickness. AGD was 19% lower as compared to contralateral Mo/Rh filtered mammogram (Fig.4.) Page 8 of 11

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10 Fig. 2: For illustration: Pat A, LCC mammogram with W/Rh filter and 38mm breast thickness. AGD was 9% lower as compared to contralateral Mo/Mo filtered mammogram (Fig.1.) - overall image quality of LCC was preferred. Fig. 4: For illustration: Pat B, L oblique mammogram with Mo/Rh filter and 51 mm breast thickness. AGD was 19% higher as compared to contralateral W/Rh filtered mammogram (Fig.3.)- overall image quality of L oblique was slightly preferred. Page 10 of 11

11 Conclusion The needle crystal technology with the Agfa DX-M system supports equivalent image quality with an approximately 50 % lower AGD compared to powder-based CR. Application of W/Rh instead of Mo/Rh has shown to allow for a further dose reduction of up to 19% without loss of diagnostic image quality. References Semturs F, Peloschek P, Zwettler G, Hummel J, Homolka P. Needle crystal detector technology in mammography-relationship between image quality and dose depending on beam quality. Rofo Oct;184(10): Young KC, Oduko JM.Technical Evaluation of Agfa DX-M Mammogra- phy CR Reader with HM5.0 Needle Image Plate. NHSBSP Equipment Report 0905, November 2009 DanceDR,YoungKC,vanEngenRE.Furtherfactorsfortheestimationofmean glandular dose using the United Kingdom, European and IAEA breast dosimetry protocols. Phys Med Biol 2009; 54: European Communities. European protocol for the quality control of the physical and technical aspects of mammography screening, Part 2b.., edited by van Engen R, van Woudenberg S, Bosmans H., Young KC, Thijssen M."EPQCVersion 4" (2006) plus"eurefsupplement for FFDM" 2010; 4th ed Figl M, Hoffmann R, Kaar M et al.factors for conversion between human and automatic readouts of CDMAM images. Med Phys 2011; 38: Personal Information Page 11 of 11