Image credits

Case-card images illustrate the topics. They are not diagnostic studies from the fictional cases.

• Motorcycle photograph

  Artur Andrzej · Original image · CC0 1.0

  Resized for web delivery and cropped for display.

• Gallbladder and common bile duct ultrasound

  Ptrump16 · Original image · CC BY-SA 4.0

  Original image pixels are unchanged; cropped for display. Any adapted image retains CC BY-SA 4.0.

• Abdominal CT

  Mikael Häggström, M.D. · Original image · CC0 1.0

  Cropped for display.

• 12-lead ECG

  MoodyGroove · Original image · Public domain

  Cropped for display. Original tracing is unchanged.

• Axial brain CT

  Department of Radiology, Uppsala University Hospital; uploaded by Mikael Häggström · Original image · CC0 1.0

  The original image is displayed without retouching.

• Normal posteroanterior chest radiograph

  Mikael Häggström · Original image · CC0 1.0

  Resized for web delivery and cropped for display.