What is shown at the arrow? (The area not white matter)

What is shown at the blue arrow?(Green)

Calculate the effective field size for a 20 x 18 cm field with a triangular corner block measuring 7 cm x 3 cm. 

If the dose at Dmax is 275 cGy, what is the dose at a depth of 13 cm, where the percent depth dose is 53.3%? 

Which of the following functions is o(n2) ?

If  f(n) = Theta(A(n))  and  g(n) = Theta(B(n)),  and B(n) is not equal to 0, what can you say about the following: f(n) + g(n) = f(n) g(n) = f(n)/g(n) =

Write the following sum in the Sum notation and then compute it 1 + 6 + 11 + 16 + … + 1001 =

Lead aprons are worn during fluoroscopy procedures to protect the radiographer from which of the following?

Which factor determines the types of target interactions that occur in the production of x-ray photons in the diagnostic range?

Which of the following primarily involves loosely bound outer-shell electrons?