This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuroradiology, Subject name: Radiology
A 45 years old man with AIDS presents with misperception, tiredness and memory loss. Which imaging feature ours a diagnosis of progressive multifocal leukoencephalopathy over HIV encephalopathy? 
Select and explain. 
A. Mass effect present, B. Contrast enhancement, C. Bilateral symmetrical periventricular lesions, D. Bilateral asymmetrical peripheral subcoical lesions.
D: Bilateral asymmetrical peripheral subcoical lesions.
Answer: D: Bilateral asymmetrical peripheral subcoical lesions. 
Explanation: HIV encephalopathy: Mild cerebral atrophy and diffuse symmetrical periventricular and deep white matter T2/FLAIR abnormality. PML: deep white matter altered signals that display low signal in T1, bright signal in T2 and FLAIR without significant enhancement after contrast administration. PML is oured over HIV encephalopathy when- Rapid progression of lesions. Hypointensity on T1 sequence. Involvement of subcoical U fibres Asymmetrical lesions Relative sparing of periventricular white matter