Normal pressure hydrocephalus

A 69-year-old woman comes to the clinic with her daughter because of memory loss and increased falls. Her daughter notes that these symptoms have been gradually worsening over the last year. She has had several falls within the past 6 months, but has had no major injuries. Her only other symptom is urinary urgency, with occasional urinary incontinence. Her past medical history includes hypertension, hyperlipidemia, and hypothyroidism, all of which are well-controlled on medications. Physical examination shows a shuffling, magnetic gait. The patient scores a 23 on a 30-point scale on the mini-mental status examination. TSH and free T4 are within normal limits and urinalysis is negative. Which of the following would most likely be seen on a brain MRI?