Skip to main content

Table 2 Dual-energy indexes for copper and lead bullets

From: Heavy metal in radiology: how to reliably differentiate between lodged copper and lead bullets using CT numbers

Measurements

Mean ± standard deviation or median (interquartile range)

Min

Max

Min

Max

SW test

t test or MW U test

CT number

ROI position

Dual energy (kVp/kVp)

Copper bullets

Lead bullets

Copper bullets

Lead bullets

p value

p value

Mean

Core

80/100

-0.047 ± 0.020

-0.035 ± 0.009

-0.091

-0.011

-0.051

-0.008

0.514

0.090

80/120

-0.068 ± 0.031

-0.060 ± 0.016

-0.140

0.014

-0.081

0.010

0.351

0.070

80/140

-0.059 ± 0.039

-0.078 ± 0.020

-0.132

0.056

-0.103

0.005

0.693

0.080

100/120

-0.021 ± 0.015

-0.025 ± 0.009

-0.050

0.027

-0.039

0.018

0.858

0.259

100/140

-0.013 ± 0.024

-0.043 ± 0.013

-0.059

0.068

-0.056

0.013

0.516

0.323

120/140

0.008 ± 0.011

-0.018 ± 0.006

-0.011

0.042

-0.029

-0.005

0.104

0.264

Max

Core

80/100

-0.038 ± 0.023

-0.034 ± 0.008

-0.099

0.004

-0.049

-0.019

0.405

0.014*

80/120

-0.054 ± 0.036

-0.060 ± 0.014

-0.139

0.017

-0.079

-0.016

0.880

0.016*

80/140

-0.042 (0.074)

-0.076 (0.015)

-0.122

0.068

-0.098

-0.021

0.014*

0.065

100/120

-0.016 ± 0.018

-0.026 ± 0.011

-0.051

0.023

-0.048

0.007

0.731

0.612

100/140

-0.005 ± 0.027

-0.042 ± 0.011

-0.050

0.075

-0.055

0.002

0.233

0.272

120/140

0.011 ± 0.013

-0.016 ± 0.009

-0.013

0.051

-0.034

0.003

0.154

0.521

Mean

Edge

80/100

-0.013 ± 0.031

-0.019 ± 0.022

-0.129

0.052

-0.082

0.047

0.150

0.829

80/120

0.015 ± 0.046

-0.025 ± 0.024

-0.158

0.111

-0.109

0.027

0.228

0.278

80/140

0.053 ± 0.050

-0.030 ± 0.031

-0.141

0.178

-0.131

0.016

0.481

0.675

100/120

0.028 (0.028)

-0.005 (0.008)

-0.029

0.065

-0.029

0.003

0.037*

0.002*

100/140

0.066 ± 0.025

-0.011 ± 0.014

-0.012

0.134

-0.050

0.017

0.114

0.232

120/140

0.039 ± 0.011

-0.004 ± 0.010

0.012

0.069

-0.037

0.025

0.062

0.418

Max

Edge

80/100

-0.004 (0.034)

-0.007 (0.016)

-0.103

0.063

-0.084

0.000

0.027*

0.065

80/120

0.028 ± 0.045

-0.021 ± 0.024

-0.131

0.094

-0.111

0.000

0.623

0.649

80/140

0.069 ± 0.050

-0.026 ± 0.031

-0.124

0.158

-0.136

0.000

0.276

0.952

100/120

0.032 (0.024)

-0.002 (0.007)

-0.028

0.073

-0.027

0.003

0.039*

0.002*

100/140

0.080 (0.028)

-0.006 (0.015)

-0.021

0.121

-0.052

0.002

0.017*

0.002*

120/140

0.040 (0.011)

-0.002 (0.005)

0.007

0.065

-0.044

0.002

0.012*

0.002*

  1. Min Minimum value, Max Maximum value, ROI Region of interest; SW test Shapiro-Wilk test; MW U test Mann-Whitney U test
  2. *Statistically significant values