Purpose : The purpose of this study is evaluating The CT image quality for pre contrast scan of CT angiography, the usefulness of neuro DSA and figure out the change of DLP with reduction of radiation exposure dose.
Material & method : The cases of CT head angiography patients of Dec. 2013 ~ Dec. 2014 were enrolled. Patients with brain tumors and arteriovenous malformations were excluded. All CT’s were scanned by Somatom Definition AS 64MDCT(Siemens) and reconstructed by Workstation Wizard(siemens). The scan conditions are 120kVp 200mAs, 120kVp 100mAs, 100kVp 100mAS. The euro DSA image of post contrast scans with contrast agent 60ml, normal saline 40ml and Rando phantom were scanned at 120kVp, 200mAs.
Results : The results of Rando Phantom Scan’s DLP at (A) 120kVp 200mAs, (B) 120kVp 100mAs, (C) 100kVp 100mAs were (A)468mGy/cm, (B) 235mGy/cm and (C) 142mGy/cm and The DLP of (B) and (C) were reduced by 49.7% and 69.6%, respectively. The Noise’s were (A) 5.1, (B) 7.1 and (C) 9.7 respectively.
Conclusion : The neuro DSA images of pre contrast scan of CT head angiography in this study were scanned at 100kVp 100mAs that was reduced radiation exposure dose by 69.6% comparing with 120kVp 200mAs and it was concluded that valuable for diagnostic.
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