title: Significant perturbation in renal functional magnetic resonance imaging parameters and contrast retention for iodixanol compared with iopromide: an experimental study using blood-oxygen-level-dependent/diffusion-weighted magnetic resonance imaging and computed tomography in rats.
abstract: OBJECTIVE
  The objective of this study was to investigate the renal changes after intravenous administration of a high dose of either iodixanol or iopromide using functional magnetic resonance imaging (MRI) and computed tomography (CT).
  
  
  METHODS
  The study was approved by the institutional committee on animal research. Seventy-two male Sprague-Dawley rats were divided into 5 cohorts, comprising normal saline (NS), iopromide, iopromide + NS, iodixanol, and iodixanol + NS. Intravenous contrast was administrated at 8 g iodine/kg of body weight. Renal CT, quantitative functional MRI of blood-oxygen-level-dependent (BOLD) imaging and diffusion-weighted imaging (DWI), and histologic examinations were performed for 18 days after contrast administration. Statistical analysis was performed by using 1-way analysis of variance, Mann-Whitney test, and regression analysis.
  
  
  RESULTS
  In the renal cortex, BOLD showed persistent elevation of R2* and DWI showed persistent suppression of apparent diffusion coefficient after iodixanol administration for 18 days. Compared with iopromide, adjusted ΔR2* (ΔR2*adj) was significantly higher in the iodixanol group from 1 hour to 18 days (P < 0.04) after contrast; adjusted ΔADC (ΔADCadj) was significantly more pronounced at day 6 (P = 0.01) after contrast. The iodixanol cohort also exhibited persistently higher attenuation in the renal cortex on CT and more severe microscopic renal cortical vacuolization up to 18 days. Intravenous hydration decreased the magnetic resonance changes in both groups but more markedly with iodixanol.
  
  
  CONCLUSIONS
  At high doses, iodixanol induced greater changes in renal functional MRI (BOLD and DWI) relative to iopromide. Combined with longer contrast retention within the kidney, this suggests that iodixanol may produce more severe and longer-lasting contrast-induced renal damage.
authors.affiliation: From the *Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Medical School of Southeast University, Nanjing, China; and †Department of Radiology, Macclesfield District General Hospital, Cheshire, United Kingdom.
authors.forename: Yuan-Cheng
authors.initials: YC
authors.lastname: Wang
authors.forename: Adrian
authors.initials: A
authors.lastname: Tang
authors.forename: Di
authors.initials: D
authors.lastname: Chang
authors.forename: Shi-Jun
authors.initials: SJ
authors.lastname: Zhang
authors.forename: Shenghong
authors.initials: S
authors.lastname: Ju
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced*; D000704:Analysis of Variance; D000818:Animals; D003287:Contrast Media / Q000633:toxicity*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004195:Disease Models, Animal; D007089:Image Enhancement / Q000379:methods; D007472:Iohexol / Q000031:analogs & derivatives* / Q000633:toxicity; D007668:Kidney / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D008297:Male; D010100:Oxygen; D051381:Rats; D017207:Rats, Sprague-Dawley; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014283:Triiodobenzoic Acids / Q000633:toxicity*
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D007472:Iohexol; C038192:iopromide; C044834:iodixanol; D010100:Oxygen