Neuroimaging Pearls For The Primary Care Provider Praveen Dayalu, MD Clinical Associate Professor Department of Neurology University of Michigan

Themes in this talk Neuroradiology is often misused Pre-test clinical assessment is critical Think about “treatable causes” Incidental findings are extremely common Age associated changes are extremely common Radiologists lack clinical information before, and feedback after, their reports

Neuroimaging Modalities CT (x-ray, ionizing radiation, with or without contrast) MRI (magnetic field and radio pulses, with or without contrast) Ultrasound– rarely used PET and SPECT imaging (radioactive tracer)

“Enhancement” Implies that contrast is visible Can be normal (e.g., blood vessels) Often pathologic– implies blood-brain barrier breakdown

Pre-contrast.

Post-contrast. Lesion enhances.

Case year old woman had cyclic vomiting as a child, and frequent headaches. Two CT’s and an MRI in her teens were normal. Now she has a new severe headache with a sparkling C- shaped scotoma moving across her vision Exam Re-image? If so, which modality?

Brain CT’s: low but measureable risk The lifetime excess risk for a head CT scan is about 1 incident cancer (any) per 1000 head CT scans for young children (<5 years) 1/2000 for exposure at age 15 years. Mathews JD et al BMJ 2013; 346: f2360 Miglioretti, DL et al JAMA Pediatr. 2013;167(8):

“Choosing Wisely”: AHS on non-emergent neuroimaging Don't neuroimage patients with stable headaches that meet criteria for migraine Don't CT for headache when MRI is available, except in emergency settings. (This matters most for young people) Loder E et al, Headache 2013; 53:

Case year old woman has chronic low back pain, depression, HTN, smoking. MRI read: “L4-5 disk bulge causing mild canal stenosis with disk-osteophyte complex narrowing the left neural foramen. Disk bulge at L5-S1 causing moderate canal stenosis. Impression: Degenerative Disk Disease” - What do you tell patient? - What do you do?

A bulging disk… but that’s life

Case -3 A 55 y/o dentist develops slurred speech, then difficulty swallowing, then left arm weakness, then progressive difficulty with walking. 7 months after onset he has a passive personality with judgment problems, and exam shows 35 lb weight loss with muscle wasting, hyperreflexia, and severe weakness in all limbs except his right arm. Neuroimage? If so, where and what modality?

Case -3 His MRI results are… (to be discussed) What did we learn about neuroimaging in this major category of neurologic disease?

Case -4 A 79 year old woman has had 3 years of walking slower, and has occasional difficulty coming up with names of acquaintances or celebrities.

Her brain MRI

MRI brain report: “ 1. Moderate enlargement of lateral ventricles. Some sulcal widening is also present. Suspicious for NPH. 2. Mild to moderate chronic small vessel ischemia in periventricular white matter and basal ganglia.” What do you tell patient What do you do?

Head and neck angiography Assess vessels (usually arteries) of neck and head CT, MR, or conventional Carotid duplex is ultrasound based, and limited Why would we do this?

Reasons for head & neck angiography Stroke workup; for acute treatment (thrombolysis, clot removal) Stroke workup for secondary prevention Evaluating for cerabral aneurysms Evaluate for other vascular problems (malformations, inflammation)

Case y/o man with history of diabetes, peripheral neuropathy, occasional fall, and recent DVT/ PE has several days of confusion and somnolence Meds: gabapentin, lisinopril, metformin, warfarin Workup?

Subdural hematoma

Emergent neuroimaging? You practice in a remote part of the UP. A small local ER is debating whether to keep emergent neuroradiology services open 24/7. For which scenarios would you like emergent neuroimaging? What modality would you need? Discuss

DWI

Cord compression