Karaciğer Metastazlarinda Düşük Dozlu Perfüzyon BT'nin Değişkenliği ve Tekrarlanabilirliği

Abstract

Hepatic perfusion CT enabling qualitative and quantitative assessment of the regional and global tumoral perfusion, have been used increasingly in recent years. However quite variability of the parameter measurements obtained by the hepatic perfusion CT leads and forces radiologists to make researches on this issue. The most important handicap for hepatic perfusion CT as the other perfusion CT examinations is the high radiation doses. With these backround knowledge the aim of this study is to determine the intra- and interobserver agreement on the perfusion measurements of very low dose hepatic perfusion CT. For this purpose 53 perfusion CT examinations were performed from 22 patients with liver metastasis from various primary cancers. Perfusion CT images obtained with a dual-source 64-row multidetector CT scanner (Definition, Siemens Medical Systems; Erlangen, Germany) in adaptive 4D spiral mode without breath-holding. Obtained perfusion parameters were prospectively analyzed by two different readers independently twice. The least variable parameters between the readers were BF and BV. There was no statistically significant diffence with these measurements. However, permeability, ALP, PVP and HPI were quite variable between readers and between reads. The effective doses of all perfusion CT studies were 2,9 mSv. Very low dose hepatic perfusion CT can be utilized for assessing therapy response in cancer patients requiring multiple recurrent perfusion examinations. However for reliable clinical applications very low dose hepatic perfusion CT should be addressed and interpreted carefully in deciding response to the therapy. Nevertheless if perfusion CT is performed for assessing therapy response, BF and BV measurements seem to be more appropriate for deciding positive or negative response.