guard that protects the cables from the moving parts the x ray source 14 is arranged to emit a beam of x rays along an axis the u201c x ray axis u201d 33 that is aligned with the center of the x ray source 14 and intersects perpendicularly the gantry axis of rotation 36 of the gantry 28 relative to the frame of the scanner 12 the detector axis 38 fig3 5 a and 5 b is offset horizontally from the x ray axis 33 and is positioned equal distances from the bottom and one end of the rectangular sensor array 22 for an example using numbers in one embodiment the panel has a rectangular sensor array 22 with an operative area 20 cm by 25 cm and the detector axis 38 is then 10 cm from each of the bottom edge 40 and one short edge 42 the left end as seen in fig2 or the right end as seen in fig3 5 a and 5 b of the sensor array 22 then when the x ray detector 20 is rotated 90 u00b0 about the detector axis 38 from the landscape orientation seen in fig5 a to a portrait orientation fig5 b the detector assumes a position where a bottom short edge 42 in portrait orientation is on the same line as the bottom long edge 40 in landscape orientation an additional embodiment also contemplated.