Objective:

To explore the differences in magnetic resonance imaging (MRI) features of children with different molecular subtypes

of medulloblastoma (MB).

Methods:

A retrospective analysis of 55 cases of MB confirmed by surgery wascarriecl

and patients were divided into four groups according to molecular subtypes. Children in each group underwent MRI plain scan

enhancement MRI and diffusion-weighted imaging (DWI) within one week before surgery. The basic signs of MRI of the lesion were compared and analyzed

and the apparent diffusion coefficient (ADC) measured of each molecular subtype

including the maximum ADC (ADCmax)

the minimum ADC (ADCmin)

and the average ADC (ADCmean) and rADC (ADC1mean/ADC2mean) wrer analyzed.

Results:

There were statistically significant differences in tumor location

enhancement manifestation

peritumoral edema

maximum diameter and ADCmax (

P

＜0.05). Among them

100.0% of Group 3 and 86.4% of Group 4 were located in the midline area

while 41.1% of WNT were located in the cerebellar hemisphere

P=0.010. In terms of tumor enhancement manifestation

27.3% of Group 4 had mild or no enhancement

and the vast majority of SHH (76.5%) and Group 3 (88.9%) showed obvious enhancement

P

=0.004; similarly

SHH often accompanied by mild or obvious peritumoral edema

while Group 3 and Group 4 often accompanied by absent or mild peritumoral edema

P

=0.024; the largest diameter showed that WNT was usually smaller than other subtypes; and ADCmax

ADCmean

ADCmin and rADC were compared

only ADCmax had statistical difference (

P

＜0.05).WNT ADCmax was the largest

which was (1.1810.572)10

-3

mm

2

/s

and SHH was the smallest

which was (0.6780.094) 10

-3

mm

2

/s.

Conclusion:

Tumor location and enhanced manifestation are of great value in predicting the molecular subtypes of MB in children. The peritumoral edema and maximum diameter of the tumor have certain auxiliary value. The value of ADCmax is still controversial.