Mammographic compression in Asian women.

Susie Lau,Kwan Hoong Ng,Yang Faridah Abdul Aziz,Pei-Yi Chu

doi:10.1371/journal.pone.0175781

Abstract

ObjectivesTo investigate: (1) the variability of mammographic compression parameters amongst Asian women; and (2) the effects of reducing compression force on image quality and mean glandular dose (MGD) in Asian women based on phantom study.MethodsWe retrospectively collected 15818 raw digital mammograms from 3772 Asian women aged 35–80 years who underwent screening or diagnostic mammography between Jan 2012 and Dec 2014 at our center. The mammograms were processed using a volumetric breast density (VBD) measurement software (Volpara) to assess compression force, compression pressure, compressed breast thickness (CBT), breast volume, VBD and MGD against breast contact area. The effects of reducing compression force on image quality and MGD were also evaluated based on measurement obtained from 105 Asian women, as well as using the RMI156 Mammographic Accreditation Phantom and polymethyl methacrylate (PMMA) slabs.ResultsCompression force, compression pressure, CBT, breast volume, VBD and MGD correlated significantly with breast contact area (p<0.0001). Compression parameters including compression force, compression pressure, CBT and breast contact area were widely variable between [relative standard deviation (RSD)≥21.0%] and within (p<0.0001) Asian women. The median compression force should be about 8.1 daN compared to the current 12.0 daN. Decreasing compression force from 12.0 daN to 9.0 daN increased CBT by 3.3±1.4 mm, MGD by 6.2–11.0%, and caused no significant effects on image quality (p>0.05).ConclusionsForce-standardized protocol led to widely variable compression parameters in Asian women. Based on phantom study, it is feasible to reduce compression force up to 32.5% with minimal effects on image quality and MGD.

Highlights

Breast compression is applied in mammography as it has several advantages including: (1) reduction of overlapping of breast tissues [1,2,3,4]; (2) reduction of scattered radiation and thereby, improves image contrast and reduces radiation dose to the breast [1,2,3, 5]; and (3) reduction of geometric and motion blurring [1,2,3]
It is feasible to reduce compression force up to 32.5% with minimal effects on image quality and mean glandular dose (MGD)
Studies revealed that the lack of consistent and objective guidelines in mammographic compression has led to large variations in both the force and pressure applied by radiographers during mammography [1, 3, 21,22,23]

Summary

Introduction

Breast compression is applied in mammography as it has several advantages including: (1) reduction of overlapping of breast tissues [1,2,3,4]; (2) reduction of scattered radiation and thereby, improves image contrast and reduces radiation dose to the breast [1,2,3, 5]; and (3) reduction of geometric and motion blurring [1,2,3]. The compression force applied is usually controlled by the radiographers They compress the breast based on the compression protocols [16,17,18,19], and according to their experience and judgment on the breast tautness, breast size, and the pain tolerance of the women. Over-compression of the breast as a result of forcestandardized protocols had been reported in several studies, in which compressed breast thickness (CBT) was not reduced even when additional compression force was applied and causing unnecessary increase in pain and discomfort without any benefits on image quality and radiation dose [11, 20, 23, 24]

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