Assessment of thermal sensitivity of CT during heating of liver: an ex vivo study.
OBJECTIVE
The purpose of this study was to assess the thermal sensitivity of CT during heating of ex-vivo animal liver.


METHODS
Pig liver was indirectly heated from 20 to 90 °C by passage of hot air through a plastic tube. The temperature in the heated liver was measured using calibrated thermocouples. In addition, image acquisition was performed with a multislice CT scanner before and during heating of the liver sample. The reconstructed CT images were then analysed to assess the change of CT number as a function of temperature.


RESULTS
During heating, a decrease in CT numbers was observed as a hypodense area on the CT images. In addition, the hypodense area extended outward from the heat source during heating. The analysis showed a linear decrease of CT number as a function of temperature. From this relationship, we derived a thermal sensitivity of CT for pig liver tissue of -0.54±0.03 HU °C(-1) with an r(2) value of 0.91.


CONCLUSIONS
The assessment of the thermal sensitivity of CT in ex-vivo pig liver tissue showed a linear dependency on temperature ≤90 °C. This result may be beneficial for the application of isotherms or thermal maps in CT images of liver tissue.
Department of Radiology, UMC Groningen, University of Groningen, Groningen, The Netherlands. g.d.pandeya@rad.umcg.nl
G D
GD
Pandeya
M J W
MJ
Greuter
B
B
Schmidt
T
T
Flohr
M
M
Oudkerk
D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D066298:In Vitro Techniques; D008099:Liver / Q000000981:diagnostic imaging* / Q000502:physiology*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D013817:Thermography / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*