Diagnostic Imaging Weekly Scan: Oct. 2, 2020

October 2, 2020

MRI and PET Reveal Parkinson's disease Duality; MRI Shows More Aggressive MS in Hispanic Patients; Radiation Dose Misconceptions; and Challenges for Racial and Ethnic Minorities in Cancer Screening

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

Before we get to our featured interview this week with Dr. Shalom Kalnicki about the challenges racial and ethnic minorities face in accessing cancer screening services and the impact of COVID-19, here are the top stories of the week.

Radiology answered a long-standing neurology question this week. Is Parkinson’s, in fact, two diseases? The answer is yes. Based on MRI and PET scans, investigators from Denmark determined Parkinson’s can either begin in the brain and move to the body or vice versa. They also hypothesized – correctly – that isolated REM sleep disorder could be directly associated with body-first disease. The published their results in the journal Brain. In their study, the team examined 37 patients – some with the isolated sleep disorder and some without it – who underwent both PET and MRI scans that were repeated after three and six years. Based on these scans, the team determined for patients with body-first disease, examining the composition of intestinal bacteria could be beneficial because Parkinson’s patients are known to have a different microbiome. Although brain-first disease is more difficult to detect because it is not picked up until movement disorders appear, the team said they hope these results add to the body of knowledge that can lead to more personalized treatment.

According to brain MRI scans, Hispanic patients are at high risk for developing more aggressive cases of multiple sclerosis. Because of that, say researchers from the University of Texas Health Sciences Center, they face a greater likelihood of clinical disability and lob loss. The team published their findings in the Journal of Neuroimaging. There has been little research into how MS affects Hispanics, but this study revealed Hispanic patients have overall lower normalized total brain, cortex, basal ganglia, corpus callosum, and white matter volumes, as well as higher lateral ventricular and T2 lesion volumes at baseline than their white counterparts, potentially indicating differential rates of neurodegeneration or inherent race-dependent brain volume differences. These measures also correlated with the higher baseline Expanded Disability Status Scale scores Hispanics had. Everything taken together, they said, points to race-dependent mechanisms that lead to the accumulation of irreversible clinical impairment in MS among this patient group.

Common misconceptions about radiation dose could be making it harder for emergency radiologists to capture the best CT images with some patients. That’s according to radiology, physics, and biomedical engineering professor Tim Szczykutowicz at the University of Wisconsin. He spoke at the American Society of Emergency Radiology annual meeting this week, highlighting how dose worries could be impacting pregnant patients, as well as those who have had several scans in the past. According to Szczykutowicz, radiologists do not need to worry about dose levels when imaging a pregnant woman suspected of pulmonary embolism. The CT levels are already so low, they do not impact the fetus, and going lower renders exams insufficient for diagnosing a condition that could kill the mother. In addition, he said, radiologists can proceed without worry with head CT in this group because there is very little leakage outside of the beam used to image the head. It would take 200 scans to impact the unborn child, he said. And, lastly, be careful how much weight you place on cumulative effective dose. Currently, there is no literature that links cumulative dose to cancer increases, nor is there a consensus about how far back to sum the exposure. Besides, he said, if you forego an exam and leave a patient with undiagnosed chest pain because you might increase their cancer risk by 0.001 percent, that patient could be dead within 24 hours from something you could have helped avoid.

And, finally this week, Diagnostic Imaging spoke with Dr. Shalom Kalnicki, chair of radiation oncology at Montefiore and Albert Einstein College of Medicine, about the challenges racial and ethnic minorities face in accessing cancer screening services, as well as the impact COVID-19 has had on this existing problem. Dr. Kalnicki also shared with us steps institutions can take to improve this situation. Here’s what he had to say.

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