Introduction A conventional X-ray examination is particularly useful in diagnosing conditions or diseases that affect the bone and chest. The dose of radiation from an X-ray tube depends on the voltage of X- ray tube (kVp, peak kilo voltage) and exposure time. These parameters define the radiation dose. It is important to limit the level of exposure parameters because it helps radiographers to create the best quality images as safely as possible. The current study was conducted on 150 patients in three different age groups (age range: 10-70 years). X-ray parameters such as the tube voltage, tube current, and exposure time were presented in the tables according to the age of patients. X-rays are ionizing radiation waves emitted as a result of differences in energy levels of electrons in atoms of X-ray anode. X-ray with high energy beam is used for medical diagnostic and therapeutic purposes. Nowadays, modern and digital medical imaging equipment improve the quality of images and reduce patient’s radiation dose. To protect the patient from unnecessary radiation dose, several technical factors should be considered (1, 2). ALARA (as low as reasonably achievable) is a principle of radioprotection that is based on minimizing radiation doses as the application of X-ray in medicine for diagnosis purposes represents the highest amount of exposure to ionizing radiation. The main technical factors are measured by applying high voltage X-ray tube, tube current, and duration of diagnoses. These factors can impact the level of radiation dose delivered to the patient (3-5). In addition, these factors can lead to the accumulation of doses and are important parameters to evaluate the quality of imaging at hospitals for subjects undergoing medical X-ray examinations. The optimization of radiation dose depends on the tube voltage (kVp), tube current (mA) of X-ray tube, exposure time of the patient to the radiation (s), and focus to detector distance (cm). The voltage of X-ray tube is an important factor which controls the amount of energy differences of electrons emitted from the X-ray tube (6, 7). The greater voltage and current increase the penetration of radiation inside the organs. The number of electrons at cathode coil is also high. While the kVp controls the quality of the Assessment of X-Ray Tube Technical Factors: Tube Voltage and Exposure Time in Erbil Medical Imaging Centers Fatiheea F Hassan 1 ID 1 Department of Basic Sciences, College of Medicine, Hawler Medical University, Kurdistan Region, Erbil, Iraq. © 2020 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (http:// creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: An evaluation of certain radiographic factors affecting patient exposure during medical imaging was carried out. Factors considered included selection of tube kilovoltage and time exposure combination. An increase in X-ray tube voltage increases the amount of radiation coming out of the X-ray tube, as well as the amount of skin dose in the image. This study aimed to assess the possibility of reducing the voltage and exposure time in medical imaging centers. The study indeed intended to protect patients from the risk of developing cancer with excessive radiation dose. Materials and Methods: This study was performed in Erbil hospitals, Iraq. NOMEX multimeter (Finland, PTW) was used to measure radiation dose (mGy), total voltage, current (mA), exposure time (s), and total filtration in 150 patients undergoing different X-ray examinations. Results: The results showed that the highest output was obtained in the age group of 42-70 years (dose range: 52.43–19.46 mGy), followed by the age group of 50-70 years (dose range: 39.9–25.63 mGy) and the age group of 10–40 years (dose range: 30.35–10.55 mGy). Conclusion: The high voltage (kVp) and high exposure time to be important factors to increase patient doses via increasing the exposure dose. Thus, optimization of exposure time and voltage is recommended for all cancer patients undergoing medical imaging with high voltage and long exposure time. Keywords: X-ray output, Voltage (Kvp), Exposure time, Radiographic projection *Correspondence to Fatiheea Fatihalla Hassan, Assistant Professor in Department of Basic Sciences, Biophysics Unit, College of Medicine, Hawler Medical University (HMU), Kurdistan Region, Erbil, Iraq. Tel: +964-7503148390; Email: fatiheea.fatihalla@ hmu.edu.krd Received: October 31, 2020, Accepted: December 9, 2020, ePublished: December 30, 2020 Open Access Scan to access more free content Disease and Diagnosis Original Article 10.34172/ddj.2020.03 Dis Diagn. 2020; 9(4):144-147 doi