TY - JOUR
T1 - Optimising the measurement of bruises in children across conventional and cross polarized images using segmentation analysis techniques in Image J, Photoshop and circle diameter measurements
AU - Harris, Ciara
AU - Alcock, A.
AU - Trefan, L
AU - Nuttall, D.
AU - Evans, S.T.
AU - Maguire, S.
AU - Kemp, A.M.
PY - 2018/1/31
Y1 - 2018/1/31
N2 - Background: Bruising is a common abusive injury in children, and it is standard practice to image and measure
them, yet there is no current standard for measuring bruise size consistently. We aim to identify the optimal
method of measuring photographic images of bruises, including computerised measurement techniques.
Methods: 24 children aged<11 years (mean age of 6.9, range 2.5–10 years) with a bruise were recruited from
the community. Demographics and bruise details were recorded. Each bruise was measured in vivo using a paper
measuring tape. Standardised conventional and cross polarized digital images were obtained. The diameter of
bruise images were measured by three computer aided measurement techniques: Image J (segmentation with
Simple Interactive Object Extraction (maximum Feret diameter), ‘Circular Selection Tool’ (Circle diameter), & the
Photoshop ‘ruler’ software (Photoshop diameter)). Inter and intra-observer effects were determined by two individuals
repeating 11 electronic measurements, and relevant Intraclass Correlation Coefficient's (ICC's) were
used to establish reliability. Spearman's rank correlation was used to compare in vivo with computerised
measurements; a comparison of measurement techniques across imaging modalities was conducted using
Kolmogorov-Smirnov tests. Significance was set at p < 0.05 for all tests.
Results: Images were available for 38 bruises in vivo, with 48 bruises visible on cross polarized imaging and 46
on conventional imaging (some bruises interpreted as being single in vivo appeared to be multiple in digital
images). Correlation coefficients were>0.5 for all techniques, with maximum Feret diameter and maximum
Photoshop diameter on conventional images having the strongest correlation with in vivo measurements. There
were significant differences between in vivo and computer-aided measurements, but none between different
computer-aided measurement techniques. Overall, computer aided measurements appeared larger than in vivo.
Inter- and intra-observer agreement was high for all maximum diameter measurements (ICC's > 0.7).
Conclusions: Whilst there are minimal differences between measurements of images obtained, the most consistent
results were obtained when conventional images, segmented by Image J Software, were measured with a
Feret diameter. This is therefore proposed as a standard for future research, and forensic practice, with the
proviso that all computer aided measurements appear larger than in vivo.
AB - Background: Bruising is a common abusive injury in children, and it is standard practice to image and measure
them, yet there is no current standard for measuring bruise size consistently. We aim to identify the optimal
method of measuring photographic images of bruises, including computerised measurement techniques.
Methods: 24 children aged<11 years (mean age of 6.9, range 2.5–10 years) with a bruise were recruited from
the community. Demographics and bruise details were recorded. Each bruise was measured in vivo using a paper
measuring tape. Standardised conventional and cross polarized digital images were obtained. The diameter of
bruise images were measured by three computer aided measurement techniques: Image J (segmentation with
Simple Interactive Object Extraction (maximum Feret diameter), ‘Circular Selection Tool’ (Circle diameter), & the
Photoshop ‘ruler’ software (Photoshop diameter)). Inter and intra-observer effects were determined by two individuals
repeating 11 electronic measurements, and relevant Intraclass Correlation Coefficient's (ICC's) were
used to establish reliability. Spearman's rank correlation was used to compare in vivo with computerised
measurements; a comparison of measurement techniques across imaging modalities was conducted using
Kolmogorov-Smirnov tests. Significance was set at p < 0.05 for all tests.
Results: Images were available for 38 bruises in vivo, with 48 bruises visible on cross polarized imaging and 46
on conventional imaging (some bruises interpreted as being single in vivo appeared to be multiple in digital
images). Correlation coefficients were>0.5 for all techniques, with maximum Feret diameter and maximum
Photoshop diameter on conventional images having the strongest correlation with in vivo measurements. There
were significant differences between in vivo and computer-aided measurements, but none between different
computer-aided measurement techniques. Overall, computer aided measurements appeared larger than in vivo.
Inter- and intra-observer agreement was high for all maximum diameter measurements (ICC's > 0.7).
Conclusions: Whilst there are minimal differences between measurements of images obtained, the most consistent
results were obtained when conventional images, segmented by Image J Software, were measured with a
Feret diameter. This is therefore proposed as a standard for future research, and forensic practice, with the
proviso that all computer aided measurements appear larger than in vivo.
KW - Bruise measurement
KW - Conventional imaging
KW - Cross polarized imaging
KW - Maximum Feret
KW - Image J
U2 - 10.1016/j.jflm.2017.12.020
DO - 10.1016/j.jflm.2017.12.020
M3 - Article
SN - 1752-928X
VL - 54
SP - 114
EP - 120
JO - Journal of Forensic and Legal Medicine
JF - Journal of Forensic and Legal Medicine
ER -