Establishment of national diagnostic reference levels (NDRL) for computed tomographic (CT) procedures in Sri Lanka: first nation-wide dose survey

2021 ◽  
Author(s):  
T Amalaraj ◽  
Duminda Satharasinghe ◽  
Aruna Pallewatte ◽  
Jeyasingam Jeyasugiththan
Keyword(s):  
Sri Lanka ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Standard Size ◽  
Dose Length Product ◽  
Computed Tomographic ◽  
Ct Dose ◽  
Contrast Enhanced ◽  
Ct Dose Index ◽  
First Time

Abstract The main purpose of this study was to establish the national diagnostic reference levels (NDRLs) for common CT procedures for the first time in Sri Lanka. Patient morphometric, exposure parameters, and dose data such as volume CT dose index (CTDIvol) and dose length product (DLP) were collected from 5666 patients who underwent 22 procedure types. The extreme dose values were filteblue before analysis to ensure that the data comes from standard size patients. The median of the dose distribution was calculated for each institution, and the third quartile value of the median distribution was consideblue as the NDRL. Based on the inclusion and exclusion criteria, 4592 patients data from 17 procedure types were consideblue for NDRL establishment covering 41\% of the country's total CT machines. The proposed NDRLs based on CTDIvol and DLP for non-contrast (NC) head:82.2 mGy/1556 mGy.cm, contrast-enhanced (CE) head: 82.2 mGy/1546 mGy.cm, chest-NC:7.4 mGy/350 mGy.cm, chest-CE:8.3 mGy/464 mGy.cm, abdomen NC:10.5 mGy/721 mGy.cm, abdomen arterial (A) phase:13.4 mGy/398 mGy.cm, abdomen venous (V) phase:10.8 mGy/460 mGy.cm, abdomen delay (D) phase:12.6 mGy/487 mGy.cm, sinus NC:30.2 mGy/452 mGy.cm, lumbar spine--NC:24.1 mGy/1123 mGy.cm, neck-NC:27.5 mGy/670 mGy.cm, high resolutions CT (HRCT) of chest:10.3 mGy/341 mGy.cm, kidney, ureter and bladder (KUB) NC:19.4 mGy/929 mGy.cm, chest to pelvis (CAP) NC:10.8 mGy/801 mGy.cm, CAP-A:10.4 mGy/384 mGy.cm, CAP-V:10.5 mGy/534 mGy.cm and CAP-D:16.8 mGy/652 mGy.cm. Although the proposed NDRLs are comparable with other countries, the observed broad dose distributions between the CT machines within the country indicate that dose optimisation strategies for Sri Lanka should be implemented for most of the CT facilities.

OPTIMIZATION OF RADIATION DOSE IN CT IMAGING: ESTABLISHING THE INSTITUTIONAL DIAGNOSTIC REFERENCE LEVELS AND PATIENT DOSE AUDITING

2019 ◽  
Vol 188 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Mohd Amir Syahmi Mat Razali ◽  
Muhamad Zabidi Ahmad ◽  
Ibrahim Lutfi Shuaib ◽  
Noor Diyana Osman
Keyword(s):  
Dose Distribution ◽  
Population Characteristics ◽  
Contrast Study ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Dose Length Product ◽  
Ct Dose ◽  
Dose Metrics ◽  
Ct Technology ◽  
Ct Dose Index

Abstract The aim of this study was to propose local diagnostic reference levels (LDRLs) for the most common computed tomography (CT) examinations (including contrast and non-contrast scan phase) performed at Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia (USM), Malaysia. A retrospective CT dose survey of 1488 subjects from January 2015 until December 2018 was performed at AMDI USM, Malaysia. The proposed DRLs were established at 50th and 75th percentile of dose distribution for all dose metrics (CT dose index [CTDI]; CTDIvol, CTDIw and dose–length product). The proposed LDRLs were compared with national DRLs and other established DRLs. The 10 most common CT examinations at AMDI were thorax–abdomen–pelvis (TAP) CT (46%), followed by pelvis CT (17%), abdomen–pelvis CT (10%), brain/head CT (9%) and other CT protocols. The local DRLs were established using the third quartile values of dose distribution and were categorized based on CT region protocols. Most of the proposed DRLs were exceeded the national DRLs (63%) and other international DRLs (67%). From the dose auditing, almost half of the recent dose data (for year 2018) exceeded the proposed local DRLs and the unusual dose were observed in TAP, brain/head and pelvis CT examinations. The unusual higher dose could be due to higher mAs settings, higher number of scan phase for contrast study and higher pitch factor. The local DRLs should be established for dose optimization and reduction of the occurrence of excessive radiation exposure to the patients. The establishment of the Ads and LDRLs should also consider all the factors that affect the variation in DRLs such as CT technology, scanning protocols and population characteristics. The local dose distribution should always be revised for improvement of the current local practice.

LOCAL STUDY OF DIAGNOSTIC REFERENCE LEVELS FOR COMPUTED TOMOGRAPHY EXAMINATIONS OF ADULT PATIENTS IN İZMIR, TURKEY

2020 ◽  
Vol 190 (4) ◽  
pp. 446-451
Author(s):  
Ayşegül Yurt ◽  
İsmail Özsoykal ◽  
Recep Kandemir ◽  
Emel Ada
Keyword(s):  
Computed Tomography ◽  
Index Volume ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Dose Length Product ◽  
Local Study ◽  
Ct Dose ◽  
International Data ◽  
Ct Dose Index ◽  
Head Neck

Abstract Purpose This study aims to develop local diagnostic reference levels (DRLs) for the most common computed tomography (CT) examinations carried out around Izmir, Turkey. Methods Five common CT examinations (head, neck, chest, abdomen–pelvis (AP), chest–abdomen–pelvis (CAP)) from four different radiology centres have been included in the study. CT dose index-volume (CTDIvol) and dose length product (DLP) values were recorded for 50 patients per exam in each centre. Third quartiles of CTDIvol and DLP values were determined as DRLs and compared with international findings. Results 51.3% of the patients were male and 48.7% were female, with a mean age of 57 (between 18 and 93). DRLs for CTDIvol were recorded as 70, 16, 15, 23 and 16 for head, neck, chest, AP and CAP examinations, respectively, while the corresponding DLPs were 1385, 604, 567, 998 and 1180 mGy.cm. Conclusion Results are mostly comparable to the latest international data, except for the head examinations, which were observed to slightly exceed the DRLs established by other countries.

Comparison of Radiation Dose in CT Examinations At PIMS with European Commission Reference Doses

2021 ◽  
Vol 17 (3) ◽  
pp. 216-221
Author(s):  
Fawad Yasin ◽  
Anum Rasheed ◽  
Muhammad Nauman Malik ◽  
Farheen Raza ◽  
Ramish Riaz ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Dose ◽  
European Commission ◽  
Large Scale ◽  
Radiology Department ◽  
Radiation Doses ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Dose Length Product ◽  
Ct Dose

OBJECTIVE - The purpose of this study was to assess the radiation dose levels from common computed tomography (CT) examinations performed in Radiology Department of Pakistan Institute of Medical Sciences (PIMS), and evaluate these according to diagnostic reference levels (DRLs) proposed by European Commission (EC) guidelines, and thus contributing towards the establishment of local and national DRLs. To the best of our knowledge, this is the first study of its kind to explore radiation doses from CT examinations in Pakistan. STUDY DESIGN - This was a quantitative study conducted at PIMS, Islamabad, spanning a duration of eight weeks. Scan parameters and dose profile data of 1506 adults undergoing examinations of head, neck, chest and abdomen-pelvis regions, comprising of single- and multi-phase, contrast-enhanced and unenhanced studies. Dose indicators utilized by EC guidelines for DRLs include volume CT dose index (CTDIvol) and Dose Length Product (DLP) for single slice and complete examination radiation doses, respectively. METHOD - Values of CTDIvol, DLP and scan lengths were extracted from the CT operators console. Other control variables included gender, contrast enhancement and phasicity of study. IBM SPSS package was used to obtain descriptive statistics such as mean and quartiles. RESULTS - DRLs calculated as 75th percentile of CTDIvol, DLP for various anatomical regions are by and far comparable to European DRLs. CONCLUSION – This study describes institutional diagnostic reference levels for common CT exams in Islamabad and provides benchmark values for future reference. Our DRL values are mostly comparable to European and international DRLs. Similar, albeit large scale, surveys are recommended for establishment of local and national DRLs, eventually contributing towards development of regional DRLs. KEYWORDS: CTDIvol, DLP, Diagnostic Reference Levels, Computed Tomography, Radiation Monitoring, Scan length

DIAGNOSTIC REFERENCE LEVELS FOR PAEDIATRIC HEAD COMPUTED TOMOGRAPHY IN MOROCCO: A NATIONWIDE SURVEY

2020 ◽  
Vol 191 (4) ◽  
pp. 400-408
Author(s):  
M Benmessaoud ◽  
A Dadouch ◽  
M Talbi ◽  
M Tahiri ◽  
Y El-ouardi
Keyword(s):  
Computed Tomography ◽  
Nationwide Survey ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Dose Length Product ◽  
Head Ct ◽  
Ct Dose ◽  
Starting Point ◽  
Effective Doses ◽  
Head Computed Tomography

Abstract The purpose of this study was to establish the diagnostic reference levels (DRLs) for paediatric head computed tomography (CT) in Morocco and to assess the effective doses received during head CT examinations. The data of 1007 patients were collected retrospectively from Moroccan university children’s hospitals. The sample was classified per age group:<1, 1–5, 5–10 and 10–15 years. The proposed DRLs were defined as 75th percentile of the distributions, which were in terms of CT dose index of 26.98, 28.88, 34.00 and 38.20 mGy and dose length product of 461.64, 540.06, 627.20 and 705.98 mGy.cm, respectively. The effective doses estimated were 3.6, 2.9, 2 and 1.79 mSv, respectively. The DRLs reported in Morocco were compared with those of other countries, which were based on the same age grouping method, including Thailand, Switzerland, Japan and the international DRLs. Our initiative via the determination of the first Moroccan diagnostic reference levels for paediatric head CT must be a starting point to spread this investigation towards other examinations and imaging modalities.

scholarly journals Doses from cervical spine computed tomography (CT) examinations in the UK

2018 ◽  
Vol 91 (1085) ◽  
pp. 20170834 ◽  
Author(s):  
John R Holroyd ◽  
Sue Edyvean
Keyword(s):  
Cervical Spine ◽  
Mean Value ◽  
Patient Dose ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Ct Dose ◽  
Spine Ct ◽  
Ct Dose Index ◽  
The Uk ◽  
Dose Index

Objective: To review doses to patients undergoing cervical spine CT examinations in the UK. Methods: A data collection form was developed and distributed to medical physicists and radiographers via e-mail distribution lists. The form requested details of CT scanners, exposure protocols and patient dose index information. Results: Data were received for 73 scanners. It was seen that 97% of scanners used automatic exposure control, and 60% of scanners used an iterative reconstruction technique for cervical spine examinations. The majority of scans were taken at 120 kV. The average patient dose indicators in terms of CT dose index (CTDIvol) ranged from 3.5 to 39.7 mGy (mean value 16.7 mGy), and for the DLP, ranged from 87 to 1030 mGy cm (mean value 379 mGy cm) as quoted for the standard 32 cm phantom. Conclusion: The rounded third quartile value of the mean dose distributions from this study were a CT dose index (CTDIvol) of 20 mGy and a dose–length product of 440 mGy cm as quoted for a 32 cm body phantom. These are significantly higher than those in the 2011 Public Health England CT dose survey when adjusted for phantom size. It is suggested that the existing national diagnostic reference levels for cervical spine CT should be amended, both with the new values and also to quote according to the 32 cm phantom. Advances in knowledge: Proposed new national diagnostic reference levels are presented for cervical spine CT examinations.

TOWARD NATIONAL CT DIAGNOSTIC REFERENCE LEVELS IN THE UNITED ARAB EMIRATES: A MULTICENTER REVIEW OF CT DOSE INDEX AND DOSE LENGTH PRODUCT

2020 ◽  
Vol 190 (3) ◽  
pp. 243-249
Author(s):  
Mohamed M Abuzaid ◽  
Wiam Elshami ◽  
A El Serafi ◽  
T Hussien ◽  
J R McConnell ◽  
...  
Keyword(s):  
Computed Tomography ◽  
United Arab Emirates ◽  
Patient Characteristics ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Dose Length Product ◽  
Ct Dose ◽  
Ct Head ◽  
Computed Tomography Dose Index ◽  
Dose Index

Abstract This multicenter study evaluated computed tomography dose index volume (CTDIvol) and dose length product (DLP) to contribute to establishing computed tomography (CT) national diagnostic reference levels (NDRLs) in the United Arab Emirates (UAE). Data from 240 patients, who underwent CT head, chest, abdomen–pelvis and urography examinations, were analyzed, including patient age, sex and weight, CTDIvol (mGy) and DLP (mGy cm). The proposed DRLs for each examination were calculated as the third quartile. DRLs are proposed using CTDIvol (mGy) and DLP (mGy cm) for CT head (67 and 1189, respectively), chest (8 and 302, respectively), abdomen–pelvis (28 and 1122, respectively) and urography (20 and 714, respectively). These values are comparable with the initial NDRLs and published international DRLs. Baseline values for International Radiology Center (IRC) CT DRLs were calculated on frequently performed CT examinations. Implementation of DRL values improves dose optimization based on procedures, scanner type and patient characteristics while maintaining acceptable image quality and diagnostic confidence.

scholarly journals Whole Body Low Dose Computed Tomography Using Third-Generation Dual-Source Multidetector With Spectral Shaping: Protocol Optimization and Literature Review

Dose-Response ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 155932582097313
Author(s):  
Dario Baldi ◽  
Liberatore Tramontano ◽  
Vincenzo Alfano ◽  
Bruna Punzo ◽  
Carlo Cavaliere ◽  
...  
Keyword(s):  
Effective Dose ◽  
Low Dose ◽  
Whole Body ◽  
Dose Length Product ◽  
Osteolytic Lesions ◽  
Subjective Image Quality ◽  
Ct Dose ◽  
Dual Source ◽  
Ct Dose Index ◽  
Low Dose Computed Tomography

For decades, the main imaging tool for multiple myeloma (MM) patient’s management has been the conventional skeleton survey. In 2014 international myeloma working group defined the advantages of the whole-body low dose computed tomography (WBLDCT) as a gold standard, among imaging modalities, for bone disease assessment and subsequently implemented this technique in the MM diagnostic workflow. The aim of this study is to investigate, in a group of 30 patients with a new diagnosis of MM, the radiation dose (CT dose index, dose-length product, effective dose), the subjective image quality score and osseous/extra-osseous findings rate with a modified WBLDCT protocol. Spectral shaping and third-generation dual-source multidetector CT scanner was used for the assessment of osteolytic lesions due to MM, and the dose exposure was compared with the literature findings reported until 2020. Mean radiation dose parameters were reported as follows: CT dose index 0.3 ± 0.1 mGy, Dose-Length Product 52.0 ± 22.5 mGy*cm, effective dose 0.44 ± 0.19 mSv. Subjective image quality was good/excellent in all subjects. 11/30 patients showed osteolytic lesions, with a percentage of extra-osseous findings detected in 9/30 patients. Our data confirmed the advantages of WBLDCT in the diagnosis of patients with MM, reporting an effective dose for our protocol as the lowest among previous literature findings.

Establishing local diagnostic reference levels for adult computed tomography in Morocco

2022 ◽  
Author(s):  
M. El Mansouri ◽  
M. Talbi ◽  
A. Choukri ◽  
O. Nhila ◽  
M. Aabid
Keyword(s):  
Computed Tomography ◽  
Adult Patients ◽  
Radiation Doses ◽  
Diagnostic Reference Levels ◽  
Reference Levels ◽  
Dose Length Product ◽  
Head Ct ◽  
Ct Examination ◽  
Japanese Studies ◽  
The Uk

In Morocco, the radiation doses received by adult patients are increasing due to the number of CT examinations performed and the larger number of computed tomography (CT) scanners installed. The aim of this study was to evaluate the radiation doses received by patients for the most common adult CT examinations in order to establish local diagnostic reference levels (DRLs). Data from 1016 adult patients were collected during 3 months from four Moroccan hospitals. Dose length product (DLP) and volumetric computed tomography dose index (CTDIvol) were evaluated by determining the 75th percentile as diagnostic reference levels for the most common examinations including head, chest and abdomen. The DRL for each examination was compared with other studies. The established DRLs in Morocco in terms of CTDIvol were 57.4, 12.3 and 10.9 for CT examinations of the head, chest, abdomen, respectively. For DLP, they were 1020, 632 and 714, respectively. These established DRLs for CTDIvol were almost similar to the UK DRLs at all examinations, higher than the Egyptian DRLs and lower than the Japanese DRLs at the head CT examination, lower than the DRLs from Egypt and Japan at the CT abdomen examination. In terms of DLP, the DRLs were higher than those of the British studies, lower than those of the Egyptian and Japanese studies at the head CT examination were higher at chest CT and lower at abdominal CT than those of all selected studies. The higher level of established DRLs in our study demonstrates the requirement of an optimization process while keeping a good image quality for a reliable diagnosis.

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