title: Cerebral CT Venography Using a 320-MDCT Scanner With a Time-Density Curve Technique and Low Volume of Contrast Agent: Comparison With Fixed Time-Delay Technique.
abstract: OBJECTIVE
  The purpose of this study was to compare a cerebral CT venography (CTV) technique performed on a 320-MDCT scanner with the use of a time-density curve (TDC) and a small volume of IV contrast medium (35 mL, with 15 mL used for the test bolus) with CTV performed using an established reference technique in which scanning is performed at a fixed time delay of 30 seconds with the use of a larger volume of contrast medium (100 mL).
  
  
  METHODS
  The time of peak enhancement was determined from the TDC generated from a scan in which a test bolus dose was used. CTV was performed at the time of peak enhancement. The diagnostic quality of 31 CTV venograms acquired using this technique was compared retrospectively with the diagnostic quality of 29 CTV venograms obtained at a fixed time delay of 30 seconds. The densities in the major venous sinuses and the degree of arterial contamination on the scans acquired using the two techniques were compared using objective and semiobjective methods. The semiobjective assessments were made independently by two neuroradiologists.
  
  
  RESULTS
  Attenuation was higher in the venous structures seen on CTV images acquired using the TDC technique. Of the scans obtained using the TDC technique, the proportion deemed to be of good quality, on the basis of a grading scale, was statistically significantly higher (p < 0.05). Also, the degree of arterial contamination was statistically significantly lower (p < 0.05). The interrater agreement for semiobjective assessments ranged from good to very good.
  
  
  CONCLUSIONS
  We describe a CTV technique performed using a low volume of IV contrast medium and a TDC on a 320-MDCT scanner. This technique provides better venous opacification and lower arterial contamination compared with use of the fixed time-delay technique.
authors.affiliation: 1 All authors: Department of Neuroradiology, The Walton Centre for Neurology and Neurosurgery, Lower Ln, Fazakerley, Liverpool, L9 7LJ, United Kingdom.
authors.forename: Shubhabrata
authors.initials: S
authors.lastname: Biswas
authors.affiliation: 1 All authors: Department of Neuroradiology, The Walton Centre for Neurology and Neurosurgery, Lower Ln, Fazakerley, Liverpool, L9 7LJ, United Kingdom.
authors.forename: Arun
authors.initials: A
authors.lastname: Chandran
authors.affiliation: 1 All authors: Department of Neuroradiology, The Walton Centre for Neurology and Neurosurgery, Lower Ln, Fazakerley, Liverpool, L9 7LJ, United Kingdom.
authors.forename: Sue
authors.initials: S
authors.lastname: Roughley
authors.affiliation: 1 All authors: Department of Neuroradiology, The Walton Centre for Neurology and Neurosurgery, Lower Ln, Fazakerley, Liverpool, L9 7LJ, United Kingdom.
authors.forename: Maneesh
authors.initials: M
authors.lastname: Bhojak
authors.affiliation: 1 All authors: Department of Neuroradiology, The Walton Centre for Neurology and Neurosurgery, Lower Ln, Fazakerley, Liverpool, L9 7LJ, United Kingdom.
authors.forename: Kumar
authors.initials: K
authors.lastname: Das
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002533:Cerebral Angiography / Q000295:instrumentation / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D008297:Male; D008875:Middle Aged; D010690:Phlebography / Q000295:instrumentation / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide
keywords: 320-MDCT; cerebral CT venography; time-density curve