title: Risk of clot formation with ionic and nonionic contrast media in cerebral angiography. Tama Contrast Media Study Group.
abstract: OBJECTIVE
  The introduction of low-osmolality contrast media has improved patient tolerance to angiographic procedures. However, nonionic contrast media may be associated with an increase in the risk of clot formation. The objective of this study was to test whether there is more clotting with nonionic agents than with ionic agents.
  
  
  METHODS
  Ninety-eight patients undergoing transfemoral cerebral angiography were randomly assigned to receive ionic (ioxaglate) (n = 62) or nonionic (iopamidol or iohexol) (n = 36) contrast material. Incidence of clot formation was examined by observation of catheters.
  
  
  RESULTS
  Clot formation was found in 4.8% of patients in the ionic contrast material group and 22.2% of patients in the nonionic contrast material group (P < .05).
  
  
  CONCLUSIONS
  Nonionic contrast media resulted in a statistically significantly higher incidence of clot formation than ionic media during cerebral catheter angiography. These results suggest that ionic contrast media are preferable in patients with risk of thrombosis.
authors.affiliation: Department of Neurosurgery, Kyorin University School of Medicine, Tokyo, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Sato
authors.forename: I
authors.initials: I
authors.lastname: Saito
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects; D002533:Cerebral Angiography; D003287:Contrast Media / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007472:Iohexol / Q000009:adverse effects; D007479:Iopamidol / Q000009:adverse effects; D007485:Ioxaglic Acid / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D011446:Prospective Studies; D012307:Risk Factors; D013927:Thrombosis / Q000139:chemically induced* / Q000453:epidemiology
chemical_list: D003287:Contrast Media; D007472:Iohexol; D007479:Iopamidol; D007485:Ioxaglic Acid