Speckled pertains to spots that are mottled, variegated--spots of a different colour from that of the main body. It is uncommonly used in neurology as it is clinically inapplicable.

Nor was there any indication of an infection in the source text.

The correct target phrase is thus: spotty areas of enhancement (in the left cerebellum) on imaging, of course.

EG.:
1)An ill-defined non-enhancing tumor (yellow arrows) is seen in the left parietal lobe with spotty areas of enhancement (red arrows). ... [http://www.meddean.luc.edu/LUMEN/MedEd/Radio/curriculum/Neur...]
2) "there was a spotty enhancement of the capsule. around the 4th ventricle (Fig. .... Large cerebellar cyst. (c). showing tu-. moural enhancement on the left ... [http://www.springerlink.com/index/w34q67443v00726v.pdf]
3) "Melanoma in a 58-year-old woman with a left cerebellar syndrome. ..... (c) Contrast-enhanced sagittal MR image shows a spotty, solid intraaxial enhancement [http://radiographics.rsnajnls.org/cgi/content/figsonly/21/2/...]