BACKGROUND:This study aimed to assess the differences in bladder parameters between neurogenic bladder (NB) patients and healthy children using Multi-modal ultrasound (MMU), thereby investigating the diagnostic significance of MMU in pediatric NB.
METHODS:Between January 2022 and September 2023, MMU examinations were conducted on 73 NB patients (NB group) and 100 healthy group (HG). Measurements upon bladder fullness included vesical volume (VV), bladder wall thickness (BWT), shear wave velocity (SWV) of the anterior wall, resistance index (RI), and vascularization index (VI). During bladder emptying, VV and anterior wall SWV were measured, and ultrasound bladder compliance (ΔC) was calculated. In this study, MMU parameters were compared between the groups, and a diagnostic model was constructed. The diagnostic performance of this model against urodynamic study (UDS) for NB was also evaluated. The correlation of MMU parameters with bladder compliance (BC) and detrusor leak point pressure (DLPP) was analyzed.
RESULTS: (1) No significant difference was found in age, gender, and BMI between the groups (P>0.05). (2) The NB group showed increased emptying VV, mean BWT, filling SWV, emptying SWV, and VI, with a decrease in ΔC compared to the HG (P<0.05), while filling VV and mean RI were not significantly different (P>0.05). (3) The parameters of filling SWV, ΔC, emptying SWV, mean BWT, and VI all demonstrated high diagnostic values, particularly filling SWV, which showed the highest value with a threshold of 2.47 m/s and an AUC of 0.89. A logistic regression equation was formulated using the three MMU parameters with the highest AUC values: Logit(P: NB) = -12.816 - 0.040 × ΔC + 3.518 × filling SWV + 2.009 × VI, predicting NB with a sensitivity of 93.15%, a specificity of 95.00%, and an accuracy of 94.22%. (4) No significant difference was observed in the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value between the diagnostic model and UDS in the diagnosis of NB (P>0.05). The diagnostic model showed a lower positive likelihood ratio and a higher negative likelihood ratio compared to UDS. (5) The NB group's BC was (19.67 ± 12.57) mL/cmH2O, and DLPP was (43.13 ± 15.48) cmH2O. BC showed a negative correlation with emptying VV, mean BWT, filling SWV, and emptying SWV, and a positive correlation with ΔC and VI (P<0.05). DLPP was positively correlated with emptying VV, mean BWT, filling SWV, and emptying SWV, and negatively correlated with ΔC and VI (P<0.05).
CONCLUSIONS: MMU serves as a viable imaging technique for the comprehensive evaluation of NB in pediatric patients. Filling SWV, among other MMU parameters, shows the highest diagnostic capability for NB. The constructed diagnostic model based on filling SWV, ΔC, and VI holds substantial diagnostic merit and may facilitate the development of an alternative to UDS.