Quantitative evaluation of diffusion-weighted MRI for differentiating benign and malignant thyroid nodules larger than 4 cm

Table 3 The diagnostic performance of meaningful single DWI parameters to identify malignant thyroid nodules

Variables	Threshold value	Yoden’s index	Accuracy%	Sensitivity%	Specificity%	PPV%	NPV%	AUC
DWI_SD	> 19.10	0.477	70.7	80.0	67.7	44.4	91.3	0.751(0.604–0.898)
DWI_SIR	> 1.20	0.432	62.2	90.0	53.2	38.3	94.3	0.734(0.604–0.864)
ADC_SD	< 88.35	0.476	75.6	65.0	77.4	48.1	87.3	0.762(0.637–0.887)
ADC_SIR	< 1.25	0.397	63.4	75.0	59.7	37.5	88.1	0.710(0.574–0.847)
ADC_min (× 10^–3 mm²/s)	< 1.13	0.735	90.2	80.0	93.5	80.0	93.5	0.933(0.874–0.992)
ADC_mean (× 10^–3 mm²/s)	< 1.47	0.535	85.3	60.0	93.5	75.0	87.9	0.851(0.759–0.944)

Abbreviations: DWI Diffusion weighted imaging, ADC Apparent diffusion coefficient, PPV Positive predictive value, NPV Negative predictive value, AUC Area under the receiver operating characteristic curve, SD Standard deviation, SIR Signal intensity rate, ADC_min Minimum apparent diffusion coefficient value, ADC_mean Mean apparent diffusion coefficient value, ADC_VSD Standard deviation of apparent diffusion coefficient value, ACR-TIRADS American College of Radiology Thyroid Imaging Reporting and Data System

ISSN: 1471-2342