Journal of Radiology
Open Access

Since Rontgen has taken the first image of his wife's hand on 22nd December 1895, the X-ray radiology system has developed continuously [1]. The Computed Tomography (CT) in 1972 is the greatest developments in medical imaging, it is generally accepted that radiation doses from Computed Tomography is significantly very high compared to X-ray due to continuous output along z-axis during scanning [2].

Radiation protection of patients has been fundamental responsibilities in medical community since have been discovering CT scan, to ensure that radiation dose in line with the concept of The guiding principle of radiation safety is ALARA (As Low As Reasonably Achievable) [3]. Efforts directed towards, accurate reference levels for CT radiation dose [4], for each examination significantly, with multi detector CT (MDCT), which have been recognized as high radiation dose, compare with other imaging techniques [5].

There are three different quantities of CT scan radiation dose, weighted computed tomography dose index (CTDIw), dose length (DLP). These values is used for characterizing radiation output of scanner [6,7], to protect the patients from the risk of ionizing radiation, that need to manage the dose levels in order to reflected the essential process of optimization the technical parameters, which effect doses of CT scan [8]. This study conduct in three medical imaging centres to compare the current radiation doses in Erbil city with other relevant literatures.

The quantities of radiation are significantly high and vary through different scanner and anatomical region. Therefore, the operators should justify, and optimize the amount of ionizing radiation doses of CT scan unnecessary to the patient [9].

This study was conducted in three medical imaging centres, Department of radiology in PAR Hospital, Hawler Hospital, and Cardiac Centre, in Erbil.

The data contain characteristics of patients, who performed CT scan procedure in these hospitals, age, weight, height and body mass index (BMI).

The technical factors of CT equipment was record for each patient tube-potential (Kv), tube current (mAs), slice thickness, and scan range. Radiation output include volume computed tomography Dose Index (CTDIv) or weighted computed tomography Dose Index (CTDIw), dose length product (DLP).

The information obtained for 335 patients that undergoing various CT examinations including head, chest, and abdomen were collected. Volume CT dose index CTDI vol is a measure of amount of energy deposited per unit mass, proportional to absorbed dose; unit is the Gray (Gy). DLP takes into account scan length; it is the product of the CTDIvol . Scan length (in centimetres), unit of DLP is mGy.cm.

Radiation doses of CT system were calculated in the program CTEXPO (Version 2.3.1, Germany), this program provide as with CTDIw and dose length product (DLP) automatically, by scanning parameters as input, which including patient age, weight, height and body mass index (BMI), the results were collected in Microsoft Excel and analysis [10].

The aim of this work was to compare radiation doses from CT scanner in Erbil hospitals with other literatures. There were three CT scanners procedures included in this data are used for diagnostic procedures. CT Expo-software calculated CTDIw, and DLP. The data were in regards to 335 of CT underwent head scanning, chest and abdomen, 120 who underwent head CT scan, 80 who underwent chest, and 140 abdomen CT examinations (Table 1).

Table 1: Patients Characteristics.

The mean age for the patients, who participated in this study ranged from 38 to 68 years old. While the mean values for weight ranged from 68 to 75 kg, and from 1.61 to 1.70 m for height respectively. The slice thickness for patients was ranged between 4.0 to 10.0 mm thicknesses, voltage CT equipment between 110 to 120 Kv for all patients examinations (Tables 2 and 3).

Table 2: CT scan equipment's parameters.

Table 3: CT-dose index volume, CT-dose index weight, and dose length product measurements.

Table 4 describe the comparison between the values of radiation doses in Erbil hospitals CTDIvol, CTDIw, and DLP with other literatures. The values of CT head, chest, and abdomen in lower level doses than Malaysia and United Kingdom.

Table 4: Comparison of CT scans doses with other literatures.

The radiation dose of Computed Tomography, is higher than other diagnostic imaging equipment, CT technique parameters including tube potential (Kvp), current product (mAs), scan length (DLP), pitch (the shift per rotation ratio), which CT dose depended on these factors [11]. The mean doses in this study and CT parameters among radiology department of each hospital, the scanner doses are in agreement with other literatures from previous study, and with National reference measurements (NDR) [12]. Significant variation was shown in tables [13,14] for head, chest, and abdomen radiation doses. Highest dose index was founding head imaging, with value of about 65.9 mGy, whereas the lowest value of 3.5 mGy was recorded for chest examination [15,16]. Variation between these examinations may be due to the use non-optimised exposure factors that deepened on adjusting mAs, or poor knowledge of protocols of scanner procedures, that would increase the risk of cancer to patients examined by CT scan [17,18]. It has been noted that necessary to monitoring the ionizing radiation in medical imaging centres in Erbil the dose must be according to age, weight, and body mass index of the patients. CT doses to recognize that invaluable diagnostic system to protect patients from that amount of radiation should be considered safe [19,20]. This study is a basis in the optimisation techniques particularly for Multislice modern CT scan units, dosage levels from scanners, and number of CT examinations.

The CTDIvol, CTDIw, and DLP for CT scan in Erbil hospitals; these presented doses were lower compared with other literatures. Radiation dose is good estimating by used of CT-Expo software, which is a useful tool for these measurements. Body mass index of patient play important role in radiation dose. Finally, it is awareness that voltage KVp) and pitch may have been affected patient dose. Dose as Low as Reasonably (ALARA), while maintaining the patient outweigh the risk.

Ethical approval was obtained from the Research Ethics Committee of the College of Medicine, Hawler Medical University, meeting Code: 8, Paper Code: 11, Date 13/10/2019.