Hicham T Abada MD, Presenter: Nothing to Disclose

Jean-Francois Paul MD, Abstract Co-Author: Nothing to Disclose

To demonstrate the feasibility of coronary CT imaging using low kilovoltage (100 kV or 80 kV) combined with ECG-pulsed tube current modulation in selected patients.

: 22 consecutive slim patients (group 1:< 60 kg, group 2: 60-70 kg; mean age: 40 years old; range, 13-77) requiring coronary CT examination were investigated by using a low kV protocol. Indications for coronary CT imaging were: atypical chest pain, heart transplant, suspicion of anomalous coronary artery. Exams were performed with 64-slice CT detector (Sensation 64, Siemens, Erlangen, Germany), rotation time of 330 ms, collimation: 0.75. Group 1: tube voltage 80 kV and tube current: 520 mAs; group 2: tube voltage 100 kV and tube current 650 mAs. Computed tomography dose index and dose length product (DLP) were recorded.

CTDIw: 15 mGy in group 1. CTDIw: 26 mGy in group 2. Mean values of (DLP), in group 1, were 122 (+/- 28 SD) corresponding to a radiation exposure of 2 mSv. Mean values of DLP, in group 2, were 246 (+/- 21 SD) corresponding to a radiation dose exposure to 4 mSv. Mean noise values were respectively 11 (+/- 2 SD) in group 1 and 9 (+/- 2 SD) in group 2.

This study demonstrated the cumulation of the beneficial effects of combination KV lowering (100 kV or 80 kV) and an automatic modulation technique (ECG-pulsed tube current modulation) for coronary CT. Substantial lowering of radiation exposure, by up to 88%, was achieved without impairment of image quality

To demonstrate the effectiveness of radiation dose reduction in a weighted adapted protocol using kV lowering approach

Abada, H, Paul, J, Optimization of Radiation Dose Exposure: The kV Lowering Approach in Cardiac CT.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4431130.html