Comparison Between Visual Assessment and Apparent Diffusion Coefficient (ADC) Value Measurement on Diffusion Weighted...

Pediatric low-grade gliomas (pLGGs) and pediatric high-grade gliomas (pHGGs) have differences prognosis, treatment strategy and outcome. This study aimed to compare diagnostic accuracy between DWI visual scale assessment and ADC value measurement of solid component of tumors in grading pediatric supratentorial gliomas.

In a current prospective study, 43 pediatric patients with pathologically-confirmed gliomas who underwent baseline DWI were enrolled between October 2023 and March 2025. The patients were classified by histopathology according to tumoral grade: 23 had pLGGs and 20 had pHGGs. Two readers reviewed DWI visual scale independently and the disagreement was resolved by consensus. On the other hand, one reader measured ADC value of entire solid component of the tumor in axial slice with greatest dimension of solid component. Two data sets of visual scale and ADC value were analyzed and the comparison of diagnostic accuracy in pediatric supratentorial glioma grading was carried out by using area under the curve (AUC) of receiver operating characteristic curve (ROC).

In terms of gender and age, there were no statistically significant differences between pLGGs and pHGGs. Regarding to DWI visual scale, there were no statistically significant differences between pLGGs and pHGGs of DWI visual scale 2, 3 and 4 with p value > 0.05. There were statistically significant differences between pLGGs and pHGGs of DWI visual scale 5 and of DWI visual assessment with p value = 0.002 and 0.002, respectively. If we used the cut off of DWI visual scale 5, the area under the curve (AUC), the sensitivity, specificity and accuracy were 0.738, 65.0%, 82.61% and 74.42%, respectively. With ADC value measurement, ADCmean, ADCmedian and ADCmin were significantly lower in pHGGs compared with pLGGs with p = 0.003, 0.005 and <0.001, respectively. The value of ADCmin had higher diagnostic ability (AUC = 0.852) compared with ADCmean and ADCmedian (AUC = 0.767 and 0.750, respectively). The optimal cut-off for ADCmin was 670x10^-6 mm²/s with Se of 80.00%, Sp of 82.61%, and Youden index of 0.626. The minimal ADC value (ADCmin) had higher area under the curve (AUC) than ADCmean, ADCmedian and DWI visual scale (0.852 to 0.767, 0.750 and 0.738). However, there were no statistically significant difference among these AUC with p = 0.368, 0.284 and 0.218 after using Delong test.

Both DWI visual scale and ADC value measurement were capable of discriminating between pLGGs and pHGGs. Although parameter of quantitative ADC value had higher area under the curve in diagnostic difference than DWI visual scale, there were no statistically significant difference among these area under the curve. Therefore, a study with larger sample size should be carried out for validate this result.