Opportunistic screening for osteoporosis by abdominal CT in a British population

Insights into Imaging

Table 2 Diagnostic performance of L1 CT attenuation values for distinguishing osteoporosis from osteopenia and normal BMD in the current study

	Threshold for achieving 90% sensitivity	Threshold for achieving 90% specificity	Threshold for balanced sensitivity and specificity
L1 CT attenuation, HU	≤ 169	≤ 104	≤ 131
Sensitivity, %	90	35	69
Specificity, %	36	90	70
PPV, %	41	63	52
NPV, %	89	75	83

CT computed tomography, PPV positive predictive value, NPV negative predictive value, HU Hounsfield units