MRI Results are in, i'm confused please help!

[kwality]

These are my MRI Results please help me understand this better. My doctor explained it but i would appreciate if some one helped me again so i can better understand before i visit the neurologist. I hope to visit him in a few day's . I've been googling the words trying to understand the whole diagnostic and would appreciate any help i can get ,

Thanking you in advance,

1)
A 1.9 x 1.4 CM EXTRAAXIAL CSF SIGNAL FLUID COLLECTION SEEN IN THE RIGHT CEREBELLOMEDULLARY ANGLE MOST LIKELY REPRESENTING AN ARACHNOID

2)
MILD MUCOSAL THICKENING SEEN IN THE LEFT ETHMOID SINUS AND A 1.0 X 0.4 MUCOSAL POLYP OR RETENTION CYST IN THE SPHENOID SINUS