Answer

Scar from Chronic Infection Clubbed Calyx or Naked Calyx CT
CT in the excretory phase in the axial projection shows a scar on the medial aspect of the superior pole of the left kidney. The clubbed calyx or naked calyx protrudes into the scar enabling a diagnosis of chronic pyelonephritis to be made
Ashley Davidoff MD TheCommonVein.net 132482