title: Comparison Between Prospectively Electrocardiogram-Gated High-Pitch Mode and Retrospectively Electrocardiogram-Gated Mode for Dual-Source CT Coronary Angiography.
abstract: BACKGROUND
  We aimed to report the image quality, relationship between heart rate and image quality, amount of contrast agent given to the patients and radiation doses in coronary CT angiography (CTA) obtained by using high-pitch prospectively ECG-gated "Flash Spiral" technique (method A) or retrospectively ECG-gated technique (method B) using 128×2-slice dual-source CT.
  
  
  METHODS
  A total of 110 patients who were evaluated with method A and method B technique with a 128×2-detector dual-source CT device were included in the study. Patients were divided into three groups based on their heart rates during the procedure, and a relationship between heart rate and image quality were evaluated. The relationship between heart rate, gender and radiation dose received by the patients was compared.
  
  
  RESULTS
  A total of 1760 segments were evaluated in terms of image quality. Comparison of the relationship between heart rate and image quality revealed a significant difference between heart rate <60 beats/min group and >75 beats/min group whereas <60 beats/min and 60-75 beats/min groups did not differ significantly. The average effective dose for coronary CTA was calculated as 1.11 mSv (0.47-2.01 mSv) for method A and 8.22 mSv (2.19-12.88 mSv) for method B.
  
  
  CONCLUSIONS
  Method A provided high quality images with doses as low as <1 mSv in selected patients who have low heart rates with a high negative predictive value to rule out coronary artery disease. Although method B increases the amount of effective dose, it provides high diagnostic quality images for patients who have a high heart rate and arrhythmia which makes it is difficult to obtain images.
authors.affiliation: Department of Radiology, Medical Faculty of Selcuk University, Konya, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Koplay
authors.affiliation: Department of Radiology, Medical Faculty of Selcuk University, Konya, Turkey.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Celik
authors.affiliation: Department of Cardiology, Medical Faculty of Selcuk University, Konya, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Avcı
authors.affiliation: Department of Radiology, Medical Faculty of Selcuk University, Konya, Turkey.
authors.forename: Hasan
authors.initials: H
authors.lastname: Erdogan
authors.affiliation: Department of Cardiology, Medical Faculty of Selcuk University, Konya, Turkey.
authors.forename: Kenan
authors.initials: K
authors.lastname: Demir
authors.affiliation: Department of Radiology, Medical Faculty of Selcuk University, Konya, Turkey.
authors.forename: Mesut
authors.initials: M
authors.lastname: Sivri
authors.affiliation: Department of Radiology, Medical Faculty of Selcuk University, Konya, Turkey.
authors.forename: Alaaddin
authors.initials: A
authors.lastname: Nayman
keywords: Coronary Angiography; Heart Rate; Image Enhancement; Multidetector Computed Tomography; Radiation Dosage; Radiology