VOLUME CT DOSE INDEX AND DOSE-LENGTH PRODUCT VALUES ACCORDING TO FACILITY SIZE IN JAPAN

Abstract The aim of this study was to investigate differences in volume computed tomography dose index (CTDIvol) and dose-length product (DLP) values according to facility size in Japan. A questionnaire survey was sent to 3000 facilities throughout Japan. Data from each facility were collected including bed number, computed tomography (CT) scan parameters employed and the CTDIvol and/or DLP values displayed on the CT scanner during each examination. The CTDIvol and DLP for 11 adult and 6 paediatric CT examinations were surveyed. Comparison of CTDIvol and DLP values of each examination according to facility size revealed key differences in CT dose between small and large facilities. This study highlights the importance of lowering the dose of coronary artery examination with contrast agent in smaller facilities and of lowering the dose of adult and paediatric head CT without contrast agent in larger facilities. The results of this study are valid in Japan.

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Optimization of head computed tomography scan in a tertiary institution in Edo State, South-South Nigeria

Medical Science and Discovery ◽

10.36472/msd.v8i4.521 ◽

2021 ◽

Vol 8 (4) ◽

pp. 225-230

Author(s):

Chikezie Chukwuemeka Udo ◽

Akintayo Daniel Omojola ◽

Chukwuemeka Christian Nzotta

Keyword(s):

Computed Tomography ◽

Ct Scanner ◽

Tertiary Institution ◽

Dose Length Product ◽

Volume Computed Tomography ◽

The United Kingdom ◽

Ct Protocol ◽

Tube Current ◽

Edo State ◽

Computed Tomography Dose Index

Objective: The study is aimed at optimizing the existing CT protocol for head scans in a Specialist Teaching Hospital in Edo State with a 16-slice Siemens Somatom Emotion scanner. Also, the study determined the volume computed tomography dose index (CTDIvol) and Dose Length Product (DLP) from the patient's dose profiles. The results from this study were compared with relevant studies. Materials and Methods: The scanner was used to acquire head CT of 160 patients retrospectively. Also, a locally designed head phantom was used to simulate individual patients using a similar protocol by changing the tube current (mA) and total scan width (TSW) only from the existing protocol. Results: Percentage dose reduction (PDR) for the CTDIvol and DLP ranged 42.00-46.80% and 37.13-43.54% respectively. The optimized CTDIvol and DLP were lowest compared to studies in the United Kingdom (UK), Italy, India, Ireland, Sudan, Nigeria, European Commission (EC), United States of America (USA) and Japan. Only the DLP for India was lower than our optimized value. Conclusion: The need to understudy CT configuration is necessary, this will allow end-users to optimize certain parameters in the CT scanner, which will reduce the patient dose without compromising image quality

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

Radiation Protection Dosimetry ◽

10.1093/rpd/ncaa100 ◽

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.

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Validation of a Locally Designed Computed Tomography Dose Phantom: A Comparison Study with a Standard Acrylic Phantom in South-South, Nigeria

Journal of Global Radiology ◽

10.7191/jgr.2021.1118 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Anwuli Christiana Tobi ◽

Chukwuka Emmanuel Mokobia ◽

Joyce Ekeme Ikubor ◽

Akintayo Daniel Omojola

Keyword(s):

Computed Tomography ◽

Cylindrical Shape ◽

Correction Factors ◽

Energy Agency ◽

Dose Length Product ◽

Ct Dose ◽

Volume Computed Tomography ◽

The Mean ◽

Computed Tomography Dose Index ◽

Dose Measurements

Purpose: The aim of this study was to determine the mean volume computed tomography dose index (CTDIvol) for the standard head and body phantoms and locally designed head and body phantoms respectively. Similarly, this study determined and compared the displayed mean CTDIvol and Dose Length Product (DLP) for the above phantoms from the CT monitor. In addition, the percentage deviations of both phantoms were compared with the recommended limits from the International Atomic Energy Agency (IAEA) and the American College of Radiologists (ACR). Materials and Methods: Dose measurements were made using a standard polymethymethacrylate (PMMA) phantom for head and body as well as a locally designed phantom with four CT scanners using thermoluminescence dosimeters (TLDs). The locally designed phantoms were made using a PMMA sheet, which was bent to give the desired cylindrical shape and was made like the standard phantoms. The constructed phantom was filled with water and the TLD chips were inserted into the center and peripheries of the phantoms to obtain the absorbed doses. Results: The CTDIvol for the standard head and body phantom for center A was 66.97 and 21.85mGy and for B was 23.39 and 6.29mGy respectively. Similarly, the CTDIvol for the constructed head and body phantom for center A was 63.91 and 19.84mGy and for B was 24.67 and 6.30mGy respectively. The uncertainty between the standard and constructed head phantoms for centers A and B was 4.6 and 5.5% respectively, while that of the standard and constructed body phantoms for centers A and B was 9.2 and 0.0% respectively. The maximum percent deviation from the console CTDIvol and DLP values with the four phantoms for centers A and B was within ±20%. The mean correction factors for the head and body were 0.998 and 1.05 respectively. Conclusion: The uncertainties obtained in this study were within the IAEA and ACR recommended value of ±20%. The constructed phantom proved useful for CT dose measurements.

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The comparison of Size-Specific Dose Estimate (SSDE) in chest CT examination calculated based on volumetric CT Dose Index (CTDIvol) reference phantom and Dose Length Product (DLP)

Journal of Physics Conference Series ◽

10.1088/1742-6596/1763/1/012065 ◽

2021 ◽

Vol 1763 (1) ◽

pp. 012065

Author(s):

Y I Binta ◽

S Suryani ◽

B Abdullah

Keyword(s):

Chest Ct ◽

Dose Length Product ◽

Dose Estimate ◽

Ct Examination ◽

Ct Dose ◽

Reference Phantom ◽

Ct Dose Index ◽

Volumetric Ct ◽

Dose Index

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Radiation Dose from Diagnostic Computed Tomography in Saskatchewan

Canadian Association of Radiologists Journal ◽

10.1016/j.carj.2009.02.035 ◽

2009 ◽

Vol 60 (2) ◽

pp. 71-78 ◽

Cited By ~ 5

Author(s):

David A. Leswick ◽

Nida S. Syed ◽

Chance S. Dumaine ◽

Hyun J. Lim ◽

Derek A. Fladeland

Keyword(s):

Computed Tomography ◽

Significant Variation ◽

Ct Scans ◽

Dose Length Product ◽

Volume Computed Tomography ◽

The United Kingdom ◽

Canadian Data ◽

Effective Doses ◽

Computed Tomography Dose Index ◽

Dose Levels

Objective To calculate the effective dose from diagnostic computed tomography (CT) scans in Saskatchewan, Canada, and compare with other reported dose levels. Methods Data from CT scans were collected from 12 scanners in 7 cities across Saskatchewan. The patient age, scan type, and selected technique parameters including the dose length product and the volume computed tomography dose index were collected for a 2-week period. This information then was used to calculate effective doses patients are exposed to during CT examinations. Data from 2,061 clinically indicated CT examinations were collected, and of them 1,690 were eligible for analysis. Every examination during a 2-week period was recorded without selection. Results The average provincial estimated patient dose was as follows: head, 2.7 mSv (638 scans; standard deviation [SD], ±1.6); chest, 11.3 mSv (376 scans; SD, ±8.9); abdomen-pelvis, 15.5 mSv (578 scans; SD, ±10.0); abdomen, 11.7 mSv (80 scans; SD, ±11.48), and pelvis, 8.6 mSv (18 scans; SD, ±6.04). Significant variation in dose between the CT scanners was observed ( P = .049 for head, P = .001 for chest, and P = .034 for abdomen-pelvis). Conclusions Overall, the estimated dose from diagnostic CT examinations was similar to other previously published Canadian data from British Columbia. This dose varied slightly from some other published standards, including being higher than those found in a review conducted in the United Kingdom in 2003.

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The comparison of bolus tracking and test bolus techniques for computed tomography thoracic angiography in healthy beagles

Journal of the South African Veterinary Association ◽

10.4102/jsava.v84i1.930 ◽

2013 ◽

Vol 84 (1) ◽

Cited By ~ 6

Author(s):

Nicolette Cassel ◽

Ann Carstens ◽

Pieter Becker

Keyword(s):

Computed Tomography ◽

Contrast Agent ◽

Test Dose ◽

Dose Length Product ◽

Bolus Tracking ◽

Iodinated Contrast ◽

Iodinated Contrast Agent ◽

Test Bolus ◽

The Mean ◽

Computed Tomography Dose Index

Computed tomography thoracic angiography studies were performed on five adult beagles using the bolus tracking (BT) technique and the test bolus (TB) technique, which were performed at least two weeks apart. For the BT technique, 2 mL/kg of 300 mgI/mL iodinated contrast agent was injected intravenously. Scans were initiated when the contrast in the aorta reached 150 Hounsfield units (HU). For the TB technique, the dogs received a test dose of 15% of 2 mL/kg of 300 mgI/mL iodinated contrast agent, followed by a series of low dose sequential scans. The full dose of the contrast agent was then administered and the scans were conducted at optimal times as identified from time attenuation curves. Mean attenuation in HU was measured in the aorta (Ao) and right caudal pulmonary artery (rCPA). Additional observations included the study duration, milliAmpere (mA), computed tomography dose index volume (CTDI[vol]) and dose length product (DLP). The attenuation in the Ao (BT = 660 52 HU ± 138 49 HU, TB = 469 82 HU ± 199 52 HU, p = 0.13) and in the rCPA (BT = 606 34 HU ± 143 37 HU, TB = 413 72 HU ± 174.99 HU, p = 0.28) did not differ significantly between the two techniques. The BT technique was conducted in a significantly shorter time period than the TB technique (p = 0.03). The mean mA for the BT technique was significantly lower than the TB technique (p = 0.03), as was the mean CTDI(vol) (p = 0.001). The mean DLP did not differ significantly between the two techniques (p = 0.17). No preference was given to either technique when evaluating the Ao or rCPA but the BT technique was shown to be shorter in duration and resulted in less DLP than the TB technique.

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Does gantry rotation time influence accuracy of volume computed tomography dose index (CTDI vol ) in modern CT?

Physica Medica ◽

10.1016/j.ejmp.2017.04.008 ◽

2017 ◽

Vol 37 ◽

pp. 43-48 ◽

Cited By ~ 5

Author(s):

Atsushi Fukuda ◽

Nao Ichikawa ◽

Yoshiharu Fujita ◽

Pei-Jan Paul Lin ◽

Kosuke Matsubara ◽

...

Keyword(s):

Computed Tomography ◽

Rotation Time ◽

Volume Computed Tomography ◽

Computed Tomography Dose Index ◽

Dose Index

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Development of indigenous cost effective pediatric head and body computed tomography dose index (CTDI) phantom for pediatric CT dose measurement

Physica Medica ◽

10.1016/j.ejmp.2014.07.156 ◽

2014 ◽

Vol 30 ◽

pp. e51

Author(s):

A. Saravanakumar ◽

K. Vaideki ◽

K.N. Govindarajan ◽

S. Jayakumar

Keyword(s):

Computed Tomography ◽

Cost Effective ◽

Dose Measurement ◽

Pediatric Ct ◽

Ct Dose ◽

Computed Tomography Dose Index ◽

Dose Index

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Establishment of diagnostic reference levels arising from common CT examinations in Semnan County, Iran

Polish Journal of Medical Physics and Engineering ◽

10.2478/pjmpe-2019-0008 ◽

2019 ◽

Vol 25 (1) ◽

pp. 51-55 ◽

Cited By ~ 3

Author(s):

Daryoush Khoramian ◽

Soroush Sistani ◽

Peyman Hejazi

Keyword(s):

Cervical Spine ◽

The Other ◽

Reference Level ◽

Ct Scanner ◽

Dose Length Product ◽

Ct Dose ◽

Patient Doses ◽

Ct Dose Index ◽

Ct Scanners ◽

Dose Levels

Abstract Objective: The literature has approved that the use of the concept of diagnostic reference level (DRL) as a part of an optimization process could help to reduce patient doses in diagnostic radiology comprising the Computed Tomography (CT) examinations. There are four public/governmental CT centers in the province (Semnan, Iran) and, to our knowledge, after about 12 years since the launch of the first CT scanner in the province there is no dosimetry information on those CT scanners. The aim of this study was to evaluate CT dose indices with the aim of the establishment of the DRL for head, chest, cervical spine, and abdomen-pelvis examinations. Methods: Scan parameters of 381 patients were collected during two months from 4 CT scanners. The CT dose index (CTDI) was measured using a calibrated ionization chamber on two cylindrical poly methyl methacrylate (PMMA) phantoms. For each sequences, weighted CTDI (CTDIw), volumetric CTDI (CTDIv) and dose length product (DLP) were calculated. The 75th percentile was proposed as the criterion for DRL values. Results: Proposed DRL (CTDIw, CTDIv, DLP) for the head, chest, cervical spine, and abdomen-pelvis were (46.1 mGy, 46.1 mGy, 723 mGy × cm), (13.8 mGy, 12.0 mGy, 377 mGy × cm), (40.0 mGy, 40.0 mGy, 572 mGy × cm) and (14.9 mGy, 12.1 mGy, 524 mGy × cm), respectively. Conclusion: Comparison with the others results from the other countries indicates that the head, chest and abdomen-pelvis scans in our region are lower or in the range of the other studies investigated in terms of dose. In the case of cervical spine scanning it’s necessary to review and regulate scan protocols to reach acceptable dose levels.

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