Quick'n'dirty: create a LOR for referenced graphics, then sort it in a text editor and check by eye? I don't have an example or the necessary information to hand, but I vaguely remember making a custom LOR that included the filename to make it even easier to get back to any instance of a referenced graphic.
T:/graphics/xen_iconEthernet.eps 13
T:/graphics/yn_connector_6.eps 13
T:/10_Yoneo/graphics/yn_iconSerial.eps 13
T:/_commonGraphics/WEEE_symbol_vectors.svg 6
T:/_commonGraphics/_wlBlue_2018pantone.eps i
T:/_commonGraphics/_wlBlue_2018pantone.eps i
T:/_commonGraphics/_wlBlue_2018pantone.eps iii
T:/_commonGraphics/_wlBlue_2018pantone.eps 1
T:/_commonGraphics/_wlBlue_2018pantone.eps 1
T:/_commonGraphics/_wlBlue_2018pantone.eps 7
T:/_commonGraphics/_wlBlue_2018pantone.eps 9
T:/_commonGraphics/_wlBlue_2018pantone.eps 23
T:/_commonGraphics/_wlBlue_2018pantone.eps 27
T:/_commonGraphics/_wlBlue_2018pantone.eps 35
T:/_commonGraphics/_wlBlue_2018pantone.eps 39
T:/_commonGraphics/tip.eps 1
T:/_commonGraphics/tip.eps 5
T:/_commonGraphics/tip.eps 7
T:/_commonGraphics/tip.eps 9
T:/_commonGraphics/tip.eps 12
T:/_commonGraphics/tip.eps 15
T:/_commonGraphics/tip.eps 16
T:/_commonGraphics/tip.eps 17
T:/_commonGraphics/tip.eps 23
T:/_commonGraphics/tip.eps 27
T:/_commonGraphics/tip.eps 40
T:/_commonGraphics/usb_Trident.eps 13
T:/_commonGraphics/usb_Trident.eps 13
T:/_commonGraphics/warning.eps 10
T:/_commonGraphics/warning.eps 14