In this series a pictorial quiz pertaining to identification of normal anatomical structures and landmarks at a given level on the computed tomography (CT) is presented. An image depicting normal anatomy is followed by a series of images showing different pathologies. Readers are expected to identify and appreciate variation and changes in the normal anatomy in presence of a given pathology. Th...

The problem of finding an energy conserving norm for the solution of the hyperbolic system of partial differential equations du/dt = Adu/dx, subject to boundary conditions, is reduced to the problem of characterizing those matrices appearing in the boundary conditions which satisfy two specific matrix equations. Necessary and sufficient conditions on the coefficient matrix A and the matrices ap...