CASE
A 28-year-old female with a history of migraines and hepatitis B infection presented to the emergency department (ED) for evaluation of a left-sided headache that began approximately 12 hours earlier. She described the headache as a squeezing sensation that had begun gradually on the left side of her neck, jaw, and left ear, with radiation to the anterior aspect of her head and nausea. The headache was intermittently relieved with OTC analgesics and rest. Within the past several months, her primary care physician had diagnosed migraines but had not ordered any imaging studies. According to the patient, this headache was different from previous headaches because it was localized to the left neck and ear and had an intensity of 4 on a 10-point scale. She denied any sick contacts, recent travel, trauma, fever, chills, photophobia, visual changes, sinus congestion, numbness, or tingling. The patient reported using oral contraceptives (OCs) for the past 2 months and ibuprofen for her headaches. The remainder of her medical history was unremarkable.
Physical examination The patient appeared well and was in no distress. Her vital signs were temperature, 36.2°C (97.2°F); heart rate, 95 beats per minute; BP 133/85 mm Hg; respirations, 16 breaths per minute; oxygen saturation was 98% on room air. Findings on the physical examination, including a detailed neurologic assessment, were unremarkable. Her laboratory test results were as follows: WBC count, 8.9×103/µL, with a normal differential; hemoglobin, 14.4 g/dL; hematocrit, 40.4%; platelets, 192×103/µL. Results of a basic metabolic panel, liver panel, and coagulation studies were normal; a urine pregnancy test was negative. The patient was given IV fluids and analgesics.
Because this headache was different from previous headaches, a CT scan of the head without contrast was ordered (Figure 1). What does the image show?