Revisiting image quality assessment A revised version PGAI

Transcription

1 Revisiting image quality assessment A revised version PGAI Deputy Chief Radiographer DCR, CCPM, GCHPE Monash BreastScreen & BSV Radiographer Training Centre (Revised for online )

2 Assessing mammographic image quality a standardised method of assessment a Cambridge Breast Unit, Addenbrookes s Hospital, Hills Road Cambridge CB2 0QQ England UK b Cancer Research Centre, University of Warwick, Coventry CV4 7AL England UK c Statistics and Epidemiology Unit, Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL England UK d Faculty of Health sciences, The University of Sydney, Camperdown, NSW,2006, Australia e Breast Imaging Centre, Oslo University Hospital, Oslo, Norway f Monash BreastScreen, 685 Centre Road East Bentleigh VIC 3165, Australia * g Rigshospitalet,Copenhagen, Denmark * h Mount Sinai Hospital, women s College Hospital, Room 574, Mount Sinai Hospital, 600 university Avenue, Toronto ON M5G 1X5, Canada Radiography 2017, Volume 23, Issue 4, * Corrected addresses from article

3 Contents Background Reason for PGAI paper Resultant criteria BSV Q group PGMI workshop Dec 2017 Test set review for consensus Review Draft PGAI used by 4 Radiogs Used alongside PGMI criteria in IQRs Early Findings/Future considerations Image quality positioning is the most important factor Image quality affects cancer detection interval cancers dose Source -K Taylor

4 USE OF PGMI Guidelines for image assessment Questionnaire sent out to countries with screening programs re PGMI use Variable interpretations of criteria Recognised criteria language non specific eg appropriate and adequate International use Variance in application Non specific Aim was to develop and validate a reproducible assessment tool

5 Process of PGAI criteria development Considerations of Anatomy structures & Importance Weighted scores Most comment re Pec and PNL noted descriptors interlink Expert panel selected from 6 countries (EP = 7) EP Mod agreement Then undertook Main set 178 cases Weighted Testing panel rads < 8 countries ( 44 rads) Mod agree within TP Fair agree TP & EP Reviewed criteria wording & level of importance (Delphi & Likert scale) Mini test set 12 cases Level of agreement with criteria for each image Likert image grade PGAI Potentially most valid, reliable evidence re inclusions & wording Quantitative

6 DESCRIPTION OF ASSESSMENT CRITERIA 1. CRITERIA SPECIFIC TO MLO IMAGE a. The inferior edge of the pectoral muscle is no more than 2cm short of a straight horizontal line drawn from the nipple to transect the posterior edge of the image such that the transection creates a right angle. This line is known as the posterior nipple line (PNL) Ensures the breast has been lifted up and out and all posterior breast tissue included 2from PNL Pectoralis muskel + - PNL-linje (posterior nipple- 1 cm over /under PNlinjen (posterior nippel b. A minimum of 3cm width of pectoral muscle line) is visible > 80 % ACR at and the upper image border and the axillary tail demonstrated Ranzcr IES line) bvee okt.2009 clear of the edge of the NNBSTC -Nottingham muscle. Signs a. and b. are inextricably linked Ensures the axillary tail is optimally visualised c. The length of the posterior nipple line is within 1cm of the posterior nipple line on the CC view (see 2f) Indicates all posterior breast tissue included d. Inframammary angle is clearly demonstrated. It should be clearly shown without any overlying or underlying tissue. Indicates that the breast has been lifted up and pulled out to ensure the inferior-posterior part of the breast is included and optimally visualised e. The nipple is in profile or transected by skin as long as the PNL meets criteria in 1a. 2 main differences of criteria The length of pec to level of nipple or horizontal posterior nipple line or within 2 cm (many sites had been using PNL drawn from nipple so perpendicular to pec) Minimum width of 3 cm of pectoral muscle at upper image border (Noted in green) Reasons also provided for relevance of criteria eg pec length requires uplift of breast with nipple horizontal if poss so posterior breast tissue is included and to meet the criteria (noted in pink )

7 Breastscreen Victoria - Radiography Q group Test set 22 cases Des Rads from 8 BSV services reviewed using current PGMI criteria Dec 2017 Workshop discussed findings and reviewed cases with most disagreement for consensus PGAI draft criteria distributed invited to use alongside PGMI for image quality reviews undertaken Review of initial results of PGAI use, suspected downgrading likely for pec length

8 Breastscreen Victoria - Radiography Q group PGMI findings 73% agreement total or 1-2 of 9 des Rads disagreed Agreed consensus 27% disagreement 6: 3 & 5: 4 between M and G gradings Most disagreement involved creases and folds and? was M or G as per pec folds seen on image on right Consensus agreed

9 PGAI Draft of PGAI devised in same format as PGMI. Suspected issues with downgrade would likely relate to pec length as in image on right G using PGMI criteria A using PGAI criteria of pec length

10 PGAI review 4 radiographers reviewed cases and applied PGAI alongside PGMI for IQRs Using draft PGAI criteria Main issues - length of pec to within 2 cm nipple Resulted in reduction of some to meet 50% PGMI grading

11 No of image cases assessed PGMI PGAI Initial PGAI results Initial results include many reviews with small numbers and need some further investigation Also needs review of application of PGAI by users as this was limitation that there was no prior discussion of use For further review and application

12 Future considerations Further discussion re interpretation of PGAI and review of its application and outcome grades vs PGMI criteria. BSV Q group to review further Review and use software now available for measurements of key anatomical features to determine range values identify? optimal range etc width, length and angle of pec pec to nipple line tangent to nipple /perpendicular with pec nipple line horizontal line Can also review Breast thickness and Breast compression values to assist review of optimal technique

13 Future considerations cont. Are there increasing challenges for radiographers with increasing obesity in population etc that impacts on achieving P/G 50% / Are demographics relevant? It has been queried if all grading criteria are so critical with use of tomosynthesis? Eg folds /creases/nipple profile I would consider that optimal imaging still required to ensure maximum breast tissue visualised and images comparable each round But? Creases and folds and downgrading?? Investigate criteria further and would like to liase with key state radiographers

14 Resultant screening images are dependant on the skills of the radiographer to consistently optimise both positioning technique + effective communication for every client presentation, this is demanding and takes consistent focus and attention to detail. Sometimes these skills are underestimated ourselves or by others. It is a challenging role and I think we should continue to investigate how we can best support continuing development of expertise, interest and the overall experience and outcomes for the women

15 Reference articles An evaluation of the use of the pectoral muscle to nipple level as a component to assess the quality of the medio-lateral oblique mammogram. SM Naylor & J York Radiography 5, Mammography image assessment; validity and reliability of current scheme. C Hill & L Robinson Radiography: 21; Comparing the use and interpretation of PGMI scoring to assess the technical quality of screening mammograms in the UK and Norway. M Boyce, R Gullien, D Parashar, K Taylor. 2015; 21; Mammography image quality; Analysis of evaluation criteria using pectoral muscle presentation. K Bentley, Ann Poulos, M Rickard. Radiography:14;