Apparent diffusion coefficients for differentiation of cerebellar tumors in children.

TLDR

Diffusion‑weighted imaging and apparent diffusion coefficient maps provide MR information that reflects cellular attenuation and integrity. The study aimed to determine whether pediatric cerebellar tumors can be differentiated by their ADC values. A retrospective review of 32 children with histologically confirmed cerebellar neoplasms (17 juvenile pilocytic astrocytomas, 8 medulloblastomas, 5 ependymomas, 2 AT/RT) compared absolute ADC values and ADC ratios of solid tumor to normal white matter using t‑tests and ANOVA. ADC values were significantly higher in juvenile pilocytic astrocytomas (1.65 ± 0.27 × 10³ mm²/s) than in ependymomas (1.10 ± 0.11 × 10³ mm²/s) and medulloblastomas (0.66 ± 0.15 × 10³ mm²/s), showing that an ADC threshold of >1.4 × 10³ mm²/s can reliably distinguish JPA from other cerebellar tumors preoperatively.

Abstract

BACKGROUND AND PURPOSE: Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps provide information at MR imaging that may reflect cell attenuation and integrity. We hypothesized that cerebellar tumors in children can be differentiated by their ADC values. METHODS: Brain MR imaging studies that included ADC maps were retrospectively reviewed in 32 patients with histologically proved cerebellar neoplasm. There were 17 juvenile pilocytic astrocytomas (JPA), 8 medulloblastomas, 5 ependymomas, and 2 rhabdoid (atypical teratoid/rhabdoid tumor [AT/RT]) tumors. Absolute ADC values of contrast-enhancing solid tumor regions and ADC ratios (ADC of solid tumor to ADC of normal-appearing white matter) were compared with the histologic diagnosis. ADC values and ratios of JPAs, medulloblastomas, and ependymomas were compared by using a 2-tailed t test and one-way analysis of variance (ANOVA). RESULTS: ADC values were significantly higher in pilocytic astrocytomas (1.65 ± 0.27) (mean ± SD) than in ependymomas (1.10 ± 0.11) (P = .0003) and medulloblastomas (0.66 ± 0.15) (P CONCLUSION: Assessment of ADC values of enhancing solid tumor is a simple and reliable technique for preoperative differentiation of cerebellar tumors in pediatric patients. Our cutoff values of >1.4 × 103 mm2/s for JPA and