The utility of electron density/effective atomic number value in dual energy computed tomography for differentiation of osteoblastic metastases and bone islands
To study the differential diagnosis value of dual energy computed tomography (CT) electron density (Rho)/ef
fective atomic number (Z) in osteoblastic metastases and bone islands.
Methods:
A total of 104 patients with malignant tumors diagnosed by pathological biopsy in Jiangsu University Affiliated AoYang Hospital from March 2020 to June 2021 were prospectively included and underwent dual-energy CT examination. All the lesions were comprehensively diagnosed based on clinical and imaging follow-up results. Among them
34 patients were diagnosed with 224 bone metastatic tumors
and 70 patients were diagnosed with 108 bone islands. The Z
Rho
dual energy index (DEI) and regular CT value (rCT) values of all lesions were measured. The differences between the parameters were compared by t test analysis. Receiver operating characteristic (ROC) curve analysis was used to compare the differential diagnostic performance of parameters for osteoblastic metastases and bone islands.
Results:
The Z
Rho
DEI
and rCT values of osteoblastic metastases and bone islands on dual-energy CT images were 11.20.7
(359.9132.1) HU
0.0620.012
(607.6211.5) HU
and 12.20.4
(582.3118.0) HU
0.0820.009
(1036.9189.1) HU. The average value of osteoblastic metastases was significantly lower than that of bone islands and the standard deviation (SD) value was higher than that of bone islands (
P
<0.001). The ROC curves showed that when the rCT value was 770.8 HU
AUC=0.886
and the corresponding sensitivity and specificity were 76.3% and 82.4%. When the thresholds of Z
Rho and DEI were 11.9
556.1 HU and 0.907
the area under curve were 0.917
0.889 and 0.907
and the corresponding sensitivities were 90.2%
94.2% and 87.9%
and specificities were 84.3%
68.5% and 84.3%
respectively.
Conclusion:
Compared with conventional CT
the utility of Rho/Z derivedof Dual-energy CT can provide Z
Rho and DEI multi-parameter quantitative values for analysis
and has better differential diagnosis performance for osteoblastic metastases and bone islands.