ROC comparison between three prediction models for both readers.

AUC is increased by adding parameters to standard MRI. The 1st model: standard MRI alone, the 2nd model: standard MRI with posttreatment 2D ADCmean, the 3rd model: standard MRI with posttreatment 2D ADCmean and posttreatment 3D ADCskewness. post- = posttreatment; 2D = single-section ROI; 3D = whole-tumor volume; ROC = receiver operating characteristic; AUC = areas under the curve.</p

Flow diagram of the study.

MRI = magnetic resonance imaging.</p

Diagnostic performances of 3D ADC measurement for treatment response.

Diagnostic performances of 3D ADC measurement for treatment response.</p

MRI of osteoblastic and chondroblastic osteosarcoma, lack of pretreatment DWI, indicating that ADC values derived from whole-tumor volume can reinforce diagnostic ability.

(A) Axial fat-suppressed (FS) contrast-enhanced T1-weighted image (T1WI) before treatment shows a tumor with extraosseous lesion (thick arrow) in distal femur. (B) Axial FS contrast-enhanced T1WI after treatment shows slight decrease in extraosseous tumor size (thick arrow), interpreted as equivocal in reader 1. (C) DWI (b of 800 sec/mm2) with ADC map after treatment shows 2D ADCminimum and 2D ADCmean of 1235μm2/sec and 1968μm2/sec, respectively. Posttreatment values are also equivocal because of neighboring cutoff values and lack of pretreatment DWI. (D) ADC histogram derived from whole-tumor volume after treatment shows 3D ADCmean of 1864μm2/sec, 3D ADCskewness of 0.185, and 3D ADCkurtosis of 4.14, suggesting a poor responder. The histopathologic finding demonstrates a poor treatment response (necrosis = 70%).</p

Bland-Altman plots of ADC measurements derived from single-section ROIs between two readers.

(A) pretreatment 2D ADCminimum, (B) posttreatment 2D ADCminimum, (C) pretreatment 2D ADCmean, and (D) posttreatment 2D ADCmean. The unit of ADC is μm2/sec. pre- = pretreatment; post- = posttreatment; ADCmin = ADCminimum.</p

Diagnostic performances of 2D ADC measurement for treatment response.

Diagnostic performances of 2D ADC measurement for treatment response.</p

Patient characteristics in all patients.

Patient characteristics in all patients.</p

Multivariate logistic regression of LDIs for diagnosis BO.

Multivariate logistic regression of LDIs for diagnosis BO.</p

Comparison of 3D ADC measurement for treatment response of osteosarcoma.

Comparison of 3D ADC measurement for treatment response of osteosarcoma.</p

Results of standard MRI analysis and diagnostic performance for treatment response of osteosarcoma.

Results of standard MRI analysis and diagnostic performance for treatment response of osteosarcoma.</p