Diagnostic Imaging's Weekly Scan: Jan. 29, 2021

January 29, 2021
Whitney J. Palmer

Perivascular Spaces & Dementia; COVID-19 Loss of Smell and Taste; NAFLD & Multi-parametric CT; Plus, Point-of-Care Ultrasound in the Pandemic Era

Welcome to Diagnostic Imaging’s Weekly Scan. I’m senior editor, Whitney Palmer.

Before we get to this week’s featured interview with Dr. Andre Kumar from Stanford University about his use of point-of-care ultrasound during the COVID-19 pandemic, here are the top stories of the week.

The past few months have revealed much about the development of dementia and cognitive decline. This week, in the journal Neurology, investigators from Australia shared their findings that large fluid-filled spaces around the small blood vessels in the brain appear more often in patients who go on to experience these neurological problems. Seen on MRI, these spaces, called perivascular spaces, clear the brain of waste and toxins, and it is thought that they also play a role in aging-associated brain changes. In a study with 414 patients with an average age of 80 years, the team captured MRI scans at baseline and every two years, as well as conducted cognitive tests along the same schedule, for eight years. They determined 31 people have severe perivascular cases and 12 individuals – 39 percent of the group – were diagnosed with dementia. These patients were more likely to experience greater cognitive decline over four years, indicating that large perivascular spaces may be biomarkers for impaired waste clearing in the brain.

Have you been wondering about how patients lose their sense of smell and taste during COVID-19 infection? Researchers from Kuwait have provided an answer in their recent publication in JAMA Neurology. And, it lies in the orbitofrontal cortex. When they examined a 25-year-old COVID-19-positive woman, they created a task-based fMRI study that alternated blocks of pleasant smells and rest. They fused these T1-weighted multi-planar images with blood-oxygen level dependent – or BOLD – maps. The images, they said, revealed a nearly consistent pattern of BOLD activation of primary and secondary olfactory areas, but the patient had no activation in the orbitofrontal cortex. The BOLD signal was strong in the right uncus/piriform cortex, though, falling in line with what is consistently being seen with COVID-19 patients.

Roughly 25 percent of adults across the globe are living with non-alcoholic fatty liver disease, but being able to identify it is difficult. MR and ultrasound elastography can successfully pinpoint liver stiffness – a surrogate condition for fibrosis – but they can require more expertise and they aren’t widely used clinically. This is where multi-parametric CT comes in, according to researchers from the University of Wisconsin. In an American Journal of Roentgenology study – and during an ARRS annual meeting – they outlined how CT parameters can enable NAFLD detection. By looking at CT images captured on 16-to-64 MDCT scanners for 186 patients with NAFLD, they determined that Fibrosis-4 index scores correlated with fibrosis to identify high-risk NAFLD. Other parameters – specifically liver segmental volume ratio and splenic volume – also performed well for detection.

And, finally this week, Diagnostic Imaging spoke with Dr. Andre Kumar, a hospitalist at Stanford University Division of Hospital Medicine. Kumar is also the co-president of the Society of Hospital Medicine Bay Area Chapter and the director of the medicine consult and procedure service. Given his particular interest in the use of point-of-care ultrasound during the pandemic era, we spoke with him about how he is using the modality, what benefits it has provided over the past year, and what the future holds for implementing the technology both with COVID-19-positive patients and individuals with other medical conditions. Here’s what he had to say.

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