Determining the effect of lowering the tube voltage from 120 kV to 100 kV in patients with acute chest pain concerning image quality and radiation dose.

MDCT is the method of choice for diagnosis, treatment planning and follow-up of coronary heart disease ,Aortic Dissection and pulmonary embolism . In spite of non stop improvements in CT technology, concerns regarding radiation exposure are still there. When performing 64-slice Coronary CT angiography (CCTA), the effective radiation dose averages usually between 10 and 15 mSv, particularly depending on the CT system, the scanning technique, as well as patient-related factor.

84 patients were included from July 2016 and July 2018. 70 of them underwent the low Kvp Technique (100 Kvp) and the other 14 underwent standard technique (120-140 kvp) Inclusion Criteria:Patients having acute chest pain and suspected to have coronary artery, pulmonary artery or aortic origin mainly. Exclusion Criteria: Known CM allergy Pregnancy Patient preparation: Low-residue diet Fasting for 6 hours Insertion of wide pore IV cannula. Beta Blockers andNitorglycerine to lower the HR below (70-65 b/min) in case of CCTA examinations. Procedure duration:5-10 Minutes....

DISCUSSION The reduction of the X-ray tube voltage, keeping a constant current, can theoretically reduce the radiation exposure exponentially. However, it has to be considered that a lower radiation dose is associated with higher image mottle, and may therefore degrade image quality. Moreover, higher attenuation levels for iodine-based CM are achieved at lower X-ray tube voltages owing to greater photoelectric effect and decreased Compton scattering. The closer the tube voltage approaches the K-edge of iodine (33.2 keV), the greater the inherent attenuation of the iodinated...

Ahmed M. Abdelwahed; Gizah/EG -Souad Kafafi universityHospital-Dar Al Fouad Hospital, Cairo prof.Dr. Mervat El Gohary , Ain shams university hospital , Cairo sherine mohamed ,Ain shams university hospital , Cairo Marwa Adel , Souad Kafafi universityHospital, Cairo Emad Hamed , Ain shams university hospital, Cairo Sherif Mohsen Shalaby, Dar Al Fouad Hospital, Cairo, CA/EG Yasser Selim, Souad Kafafi universityHospital, Cairo/EG

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