title: [CT manifestation in comparison with histopathological findings of radiation-induced liver disease in pigs: a pilot study].
abstract: OBJECTIVE
  To study the pathological basis of radiological reaction types of radiation-induced liver disease on multiphasic CT scans.
  
  
  METHODS
  Three pigs (tagged with A, B, and C) were subjected to single-dose radiation of 40, 40 and 30 Gy on the right or left lobe of the liver, respectively. At 42, 56, 133, and 168 days after irradiation, all pigs were examined with non-enhanced scan and contrast-enhanced scans at different time points after contrast injection. Hounsfield units (HU) were measured in each CT study to evaluate the density of irradiated and non-irradiated liver tissue to determine the reaction type. Liver tissues in the irradiation area obtained by needle biopsy with CT guidance were examined with electron microscopy, and specimens of the tissue corresponding to the region of interest on CT were obtained from necropsies for pathological examination.
  
  
  RESULTS
  Radiologically, the 3 pig models presented with 3 reaction types on the multiphasic CT scans on days 133, 56, and 168 after radiation, respectively. Type 1 presented constant low-density change in all phases, the pathological basis of which was radiation hepatitis; type 2 showed pre-contrast phase isodense, arterial phase hyperdense, portal phase isodense and later phase hyperdense changes; type 3 was characterized by pre-contrast phase isodense, arterial phase hyperdense, portal phase hypodense and later phase hyperdense changes. The pathological basis of the last two radiological reaction types was radiation cirrhosis (postnecrotic cirrhosis).
  
  
  CONCLUSIONS
  Different radiological reaction types of radiation liver injury on multiphase CT have different pathological basis, and multiphase contrast-enhanced CT may help distinguish the radiation reactions from tumor recurrence.
authors: Department of Radiation Oncology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. guoyu@fimmu.com
authors: Xiao-Xia
authors: XX
authors: Zhu
authors: Long-Hua
authors: LH
authors: Chen
authors: De-Hua
authors: DH
authors: Wu
mesh_terms: D000818:Animals; D005260:Female; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D010865:Pilot Projects; D011833:Radiation Injuries, Experimental / Q000000981:diagnostic imaging* / Q000473:pathology*; D013194:Staining and Labeling; D013552:Swine; D014057:Tomography, X-Ray Computed