scholarly journals Radiation exposure of computed tomography imaging for the assessment of acute stroke

2020 ◽  
Author(s):  
Sebastian Zensen ◽  
Nika Guberina ◽  
Marcel Opitz ◽  
Martin Köhrmann ◽  
Cornelius Deuschl ◽  
...  

Abstract Purpose To assess suspected acute stroke, the computed tomography (CT) protocol contains a non-contrast CT (NCCT), a CT angiography (CTA), and a CT perfusion (CTP). Due to assumably high radiation doses of the complete protocol, the aim of this study is to examine radiation exposure and to establish diagnostic reference levels (DRLs). Methods In this retrospective study, dose data of 921 patients with initial CT imaging for suspected acute stroke and dose monitoring with a DICOM header–based tracking and monitoring software were analyzed. Between June 2017 and January 2020, 1655 CT scans were included, which were performed on three different modern multi-slice CT scanners, including 921 NCCT, 465 CTA, and 269 CTP scans. Radiation exposure was reported for CT dose index (CTDIvol) and dose-length product (DLP). DRLs were set at the 75th percentile of dose distribution. Results DRLs were assessed for each step (CTDIvol/DLP): NCCT 33.9 mGy/527.8 mGy cm and CTA 13.7 mGy/478.3 mGy cm. Radiation exposure of CTP was invariable and depended on CT device and its protocol settings with CTDIvol 124.9–258.2 mGy and DLP 1852.6–3044.3 mGy cm. Conclusion Performing complementary CT techniques such as CTA and CTP for the assessment of acute stroke increases total radiation exposure. Hence, the revised DRLs for the complete protocol are required, where our local DRLs may help as benchmarks.

2013 ◽  
Vol 64 (2) ◽  
pp. 119-129 ◽  
Author(s):  
Aaron Sodickson

Many tools and strategies exist to enable reduction of radiation exposure from computed tomography (CT). The common CT metrics of x-ray output, the volume CT dose index and the dose-length product, are explained and serve as the basis for monitoring radiation exposure from CT. Many strategies to dose-optimize CT protocols are explored that, in combination with available hardware and software tools, allow robust diagnostic quality CT to be performed with a radiation exposure appropriate for the clinical scenario and the size of the patient. Specific emergency department example protocols are used to demonstrate these techniques.


Author(s):  
Denise Bos ◽  
Britta König ◽  
Sebastian Blex ◽  
Sebastian Zensen ◽  
Marcel Opitz ◽  
...  

Abstract The aim of this phantom study is to examine radiation doses of dual- and single-energy computed tomography (DECT and SECT) in the chest and upper abdomen for three different multi-slice CT scanners. A total of 34 CT protocols were examined with the phantom N1 LUNGMAN. Four different CT examination types of different anatomic regions were performed both in single- and dual-energy technique: chest, aorta, pulmonary arteries for suspected pulmonary embolism and liver. Radiation doses were examined for the CT dose index CTDIvol and dose-length product (DLP). Radiation doses of DECT were significantly higher than doses for SECT. In terms of CTDIvol, radiation doses were 1.1–3.2 times higher, and in terms of DLP, these were 1.1–3.8 times higher for DECT compared with SECT. The third-generation dual-source CT applied the lowest dose in 7 of 15 different examination types of different anatomic regions.


2020 ◽  
Vol 188 (2) ◽  
pp. 261-269
Author(s):  
Yuta Matsunaga ◽  
Yuya Kondo ◽  
Kenichi Kobayashi ◽  
Masanao Kobayashi ◽  
Kazuyuki Minami ◽  
...  

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.


2020 ◽  
Vol 190 (4) ◽  
pp. 446-451
Author(s):  
Ayşegül Yurt ◽  
İsmail Özsoykal ◽  
Recep Kandemir ◽  
Emel Ada

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.


Dose-Response ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 155932582097313
Author(s):  
Dario Baldi ◽  
Liberatore Tramontano ◽  
Vincenzo Alfano ◽  
Bruna Punzo ◽  
Carlo Cavaliere ◽  
...  

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.


2015 ◽  
Vol 6 (3) ◽  
pp. ar.2015.6.0134 ◽  
Author(s):  
Joseph M. Hoxworth ◽  
Devyani Lal

Background Sinus computed tomography (CT) is performed for the diagnosis of paranasal sinus disease and to assess response to medical therapy. In addition, sinus CT is used for intraoperative imaging guidance. Multiple CTs increase cost and radiation exposure. Objective To determine potential cost savings and radiation dose reduction that result from the use of a single universal sinus CT protocol for diagnostic imaging and intraoperative navigation. Materials and Methods For sinus CT at the authors' institution, a single imaging protocol was begun and deemed acceptable by neuroradiologists and surgeons for diagnostic imaging and intraoperative guidance. The electronic medical record was queried over a 4-year period to determine the number of sinus CTs performed, dose-length products, referring providers' specialties, percentage of CTs used for intraoperative navigation, and the elapsed time between CT and surgery. Results A total of 6187 sinus CTs were performed by using a 64-detector scanner during the study period (2759 women and 3428 men; 53.6 ± 16.7 years [mean ± SD]), and 596 endoscopic sinus surgery cases used imaging guidance, for which all the CTs were deemed technically adequate. The mean dose-length product for the CTs was 338.4 ± 31.9 mGy-cm (mean ± SD). Of the 3702 sinus CTs ordered by nonotolaryngology providers, 167 surgeries with intraoperative navigation (4.5%) were performed. A higher percentage of CT referrals from sinus surgeons (23.9%) and other otolaryngology providers (11.4%) was used for imaging guidance (p < 0.0001). The time interval between sinus CT and surgery was greatest for nonotolaryngology providers (63.1 days, p < 0.01). Based on Medicare reimbursement, the total estimated saving was $147,628. Conclusions Adopting a single universal sinus CT protocol for diagnostic imaging and intraoperative navigation can be an effective means of decreasing cost and radiation exposure. However, successful implementation must take into account multiple practice-based considerations.


2021 ◽  
Vol 8 (4) ◽  
pp. 225-230
Author(s):  
Chikezie Chukwuemeka Udo ◽  
Akintayo Daniel Omojola ◽  
Chukwuemeka Christian Nzotta

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


Author(s):  
Mohammed Ahmed Ali Omer

Background: A retrospective study presenting the endemic orbital infection (cellulitis) that breakout during dusty storm season; aiming to ascertain and showing the precedence of MRI for diagnosis of orbital infection rather than CT and revealing the diagnostic abilities of cross-sectional matrices spectrum.Methods: Based on retrospective collection of diagnostics (CT and MRI) information for randomly selected patients with cellulitis and the targeting the relevant data (image interpretation, exposure dose (DLP and CTDIvol), age, BMI and matrix cross-section spectrum findings).Results: The exposure dose of orbital CT exam was 59.4 (mGy) as CT dose index (CTDIvol) and 917.3 (mGy/cm) as dose length product (DLP) that increase by increment of age and BMI. The obese patients only exposed to dose exceeding the National Diagnostic Reference by 2.8%. MRI confirmed the inflammation around the optic nerve and extension to posterio-inferior portion of the globe and affecting the optic nerve with left sided proptosis (0.5cm) better than CT. The cross-sectional matrix successfully revealed that: the Lt optic nerve’s gray value (density) increases by a factor of 17.7 (a u) and enlarged by 5 pixels greater than the Rt optic nerve. Thickening, rough surface increased gray value by 30.5 (a u), muco-thickening and choncheal enlargement at the medial boarder of Lt orbit as 10.0 pixel and Lt eye ball enlarged by a factor of 10.9 pixels.Conclusions: MRI wisely diagnose orbital infection with more details and overcoming patient radiation exposure and usage of image spectrum gives detailed characterization of lesion morphology.


2021 ◽  
Vol 17 (3) ◽  
pp. 216-221
Author(s):  
Fawad Yasin ◽  
Anum Rasheed ◽  
Muhammad Nauman Malik ◽  
Farheen Raza ◽  
Ramish Riaz ◽  
...  

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


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