Learn to master subtle stroke cases on CT and MRI! Gain experience detecting strokes on CT by reviewing the 25 cases of subtle strokes presented in this module. The purpose is not to comprehensively explain the role of imaging in the evaluation of acute stroke or to teach a junior physician how to approach a CT scan of the brain. Instead, by reviewing these difficult cases, the reader will become better at detecting the subtle CT findings of acute stroke. Some of these cases were initially interpreted correctly. Many were not.

Some may say that stroke is a clinical diagnosis and that the role of non-contrast CT is to exclude hemorrhage so that treatment can commence. This may be true given the increased availability of CTA, CT perfusion, and MRI perfusion. So why look at difficult cases? While it is valuable to diagnose a stroke on CT when the findings are present, there are instances where stroke is not considered clinically. This is particularly true in cases with clinical histories of confusion or altered mental status, or in young patients with suspected severe migraines. Making the diagnosis in these situations could significantly impact the treatment approach. In addition, identifying the subtle changes in acute stroke is necessary for grading early stroke severity (such as creating an ASPECTS score) which can affect treatment options.

Instructions:

Each case contains a non-contrast CT scan and either a follow-up CT or MRI. Review the initial exam and try to find the infarct, then look at the follow-up exams to see if you were correct. After answering a quiz question, review the images in the study, a sample report, case discussion, and specific teaching points relevant to the case.

With each case you complete, you’ll receive an updated  Mastery Score to monitor your ongoing performance! Challenge yourself today and improve your confidence reading and reporting on subtle stroke cases.