An imaging system, wherein the imaging system is a medical computed tomography scanner comprising: a radiation source, including an anode, that is adapted to rotate around an examination region about a longitudinal axis and adapted to emit radiation from a focal spot on the anode; said anode having an anode angle characterised by a source collimator that is adapted to collimate the emitted radiation to produce a conically shaped radiation beam that traverses the examination region, wherein the conically shaped radiation beam has an extended cone angle along the longitudinal axis that is greater than an effective maximum cone angle defined by a limitation of the cone angle by the heel effect, wherein, as the cone angle increases beyond the effective maximum cone angle, the intensity of rays falls off and the rays are attenuated due to the heel effect, which attenuates and hardens the rays emanating from the focal spot on the anode side of an axis (204, 510) which extends perpendicularly from the focal spot through the longitudinal axis, wherein the collimator is positioned to collimate the emitted radiation emanating from the focal spot such that said extended cone angle on the heel side is greater than the anode angle; a detector array that is adapted to detect radiation that traverses the examination region and generate signals indicative thereof; and a reconstructor that is adapted to reconstruct the signals to generate volumetric image data indicative of the examination region; wherein the medical computed tomography scanner further comprises a data corrector that is adapted to correct the signal for the heel effect, wherein the data corrector is adapted to correct for both increased attenuation and beam hardening. a radiation source, including an anode, that is adapted to rotate around an examination region about a longitudinal axis and adapted to emit radiation from a focal spot on the anode; said anode having an anode angle characterised by a source collimator that is adapted to collimate the emitted radiation to produce a conically shaped radiation beam that traverses the examination region, wherein the conically shaped radiation beam has an extended cone angle along the longitudinal axis that is greater than an effective maximum cone angle defined by a limitation of the cone angle by the heel effect, wherein, as the cone angle increases beyond the effective maximum cone angle, the intensity of rays falls off and the rays are attenuated due to the heel effect, which attenuates and hardens the rays emanating from the focal spot on the anode side of an axis (204, 510) which extends perpendicularly from the focal spot through the longitudinal axis, wherein the collimator is positioned to collimate the emitted radiation emanating from the focal spot such that said extended cone angle on the heel side is greater than the anode angle; a detector array that is adapted to detect radiation that traverses the examination region and generate signals indicative thereof; and a reconstructor that is adapted to reconstruct the signals to generate volumetric image data indicative of the examination region; wherein the medical computed tomography scanner further comprises a data corrector that is adapted to correct the signal for the heel effect, wherein the data corrector is adapted to correct for both increased attenuation and beam hardening.