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.

Experimental Examination of Radiation Doses Of Dual- and Single-Energy Computed Tomography in Chest And Upper Abdomen in a Phantom Study

2021 ◽  
Author(s):  
Denise Bos ◽  
Britta König ◽  
Sebastian Blex ◽  
Sebastian Zensen ◽  
Marcel Opitz ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pulmonary Arteries ◽  
Phantom Study ◽  
Radiation Doses ◽  
Experimental Examination ◽  
Dose Length Product ◽  
Ct Dose ◽  
Dual Source ◽  
Ct Dose Index ◽  
Upper Abdomen

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.

Reduced Kilovoltage in Computed Tomography–Guided Intervention in a Community Hospital: Effect on the Radiation Dose

2014 ◽  
Vol 65 (4) ◽  
pp. 345-351 ◽  
Author(s):  
Saman Rezazadeh ◽  
Steven J. Co ◽  
Simon Bicknell
Keyword(s):  
Low Dose ◽  
Effective Diameter ◽  
Tube Voltage ◽  
Dose Length Product ◽  
Ct Guided ◽  
Ct Dose ◽  
Patient Size ◽  
Ct Dose Index ◽  
Volume Ct ◽  
Dose Index

Purpose The purpose of this study was to determine whether low-kilovoltage (80 or 100 kV) computed tomography (CT)-guided interventions performed in a community-based hospital are feasible and to compare radiation exposure incurred with conventional 120 kV potential. Materials and Methods Effective doses (ED) received by patients who underwent CT-guided intervention were analysed before and after a low-dose kilovoltage protocol was instituted in our department. We performed CT-guided procedures of 93 consecutive patients by using conventional 120-kV tube voltage (50 patients) and a low voltage of 80 or 100 kV for the remainder of this cohort. Automatic tube current modulation was enabled to obtain the best image quality. Procedure details were prospectively recorded and included examination site and type, slice width, tube voltage and current, dose length product, volume CT dose index, and size-specific dose estimate. Dose length product was converted to ED to account for radiosensitivity of specific organs. Statistical comparisons with test differences in the ED, volume CT dose index, size-specific dose estimate, and effective diameter (patient size) were made by using the Student t test. Results All but 6 of the procedures performed at 80 kV were successful, for a success rate of 86%. At lower voltages, the ED was significantly ( P < .01) reduced, on average, by 57%, 73%, and 65% for the pelvic, chest, and abdomen procedures, respectively. Conclusion A low-dose radiation technique by using 80 or 100 kV results in a high technical success rate for pelvic, chest, and abdomen CT-guided interventional procedures, although dramatically decreasing radiation exposure. There was no significant difference in effective diameter (patient size) between the conventional and the low-dose groups, which would suggest that dose reduction was indeed a result of kVp change and not patient size.

scholarly journals Preferred characterization of orbital infection (cellulitis) with exposure dose and relative medication

2019 ◽  
Vol 7 (2) ◽  
pp. 605
Author(s):  
Mohammed Ahmed Ali Omer
Keyword(s):  
Optic Nerve ◽  
Image Interpretation ◽  
Exposure Dose ◽  
Dose Length Product ◽  
Cross Sectional ◽  
Ct Dose ◽  
Cross Section Spectrum ◽  
Ct Dose Index ◽  
Patient Radiation Exposure

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.

scholarly journals DIAGNOSTIC IMAGING AND IONIZING RADIATION EXPOSURE IN A LEVEL 1 TRAUMA CENTRE POPULATION MET WITH TRAUMA TEAM ACTIVATION: A ONE-YEAR PATIENT RECORD AUDIT

2020 ◽  
Vol 189 (1) ◽  
pp. 35-47
Author(s):  
Anna Bågenholm ◽  
Pål Løvhaugen ◽  
Rune Sundset ◽  
Tor Ingebrigtsen
Keyword(s):  
Diagnostic Imaging ◽  
Radiation Exposure ◽  
Effective Dose ◽  
Trauma Team ◽  
Trauma Centre ◽  
Whole Body ◽  
Reference Level ◽  
Dose Length Product ◽  
Trauma Team Activation ◽  
X Ray

Abstract This audit describes ionizing and non-ionizing diagnostic imaging at a regional trauma centre. All 144 patients (males 79.2%, median age 31 years) met with trauma team activation from 1 January 2015 to 31 December 2015 were included. We used data from electronic health records to identify all diagnostic imaging and report radiation exposure as dose area product (DAP) for conventional radiography (X-ray) and dose length product (DLP) and effective dose for CT. During hospitalization, 134 (93.1%) underwent X-ray, 122 (84.7%) CT, 92 (63.9%) focused assessment with sonography for trauma (FAST), 14 (9.7%) ultrasound (FAST excluded) and 32 (22.2%) magnetic resonance imaging. One hundred and sixteen (80.5%) underwent CT examinations during trauma admissions, and 73 of 144 (50.7%) standardized whole body CT (SWBCT). DAP values were below national reference levels. Median DLP and effective dose were 2396 mGycm and 20.42 mSv for all CT examinations, and 2461 mGycm (national diagnostic reference level 2400) and 22.29 mSv for a SWBCT.

scholarly journals Value of whole-body low-dose computed tomography in patients with ventriculoperitoneal shunts: a retrospective study

2018 ◽  
Vol 129 (6) ◽  
pp. 1598-1603 ◽  
Author(s):  
Andrej Pala ◽  
Fadi Awad ◽  
Michael Braun ◽  
Michal Hlavac ◽  
Arthur Wunderlich ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Radiation Exposure ◽  
Low Dose ◽  
Whole Body ◽  
Consecutive Series ◽  
Dose Length Product ◽  
Shunt System ◽  
Distal Catheter ◽  
Vp Shunt

OBJECTIVEThe gold standard for evaluation of ventriculoperitoneal (VP) shunt position, dislocation, or disconnection is conventional radiography. Yet, assessment with this modality can be challenging because of low image quality and can result in repetitive radiation exposure with high fluctuation in the radiation dose. Recently, CT-based radiation doses have been significantly reduced by using low-dose protocols. Thus, whole-body low-dose CT (LDCT) has become applicable for routine use in VP shunt evaluation. The authors here compared image quality and approximate radiation dose between radiography and LDCT in patients with implanted VP shunt systems.METHODSVentriculoperitoneal shunt systems have been investigated with LDCT scanning at the authors’ department since 2015. A consecutive series of 57 patients (70 investigations) treated between 2015 and 2016 was retrospectively assessed. A historical patient cohort that had been evaluated with radiography was compared with the LDCT patients in terms of radiation dose and image quality. Three independent observers evaluated projection of the valve pressure level and correct intraperitoneal position, as well as complete shunt projection, using a Likert-type scale of 1–5, where 1 indicated “not assessable” and 5 meant “assessable with high accuracy.” Descriptive statistics and the Mann-Whitney U-test were used for analysis.RESULTSTwenty-seven radiographs (38.6%) and 43 LDCT scans (61.4%) were analyzed. The median dose-length product (DLP) of the LDCT scans was 100 mGy·cm (range 59.9–183 mGy·cm). The median total dose-area product (DAP) of the radiographic images was 3177 mGy·cm2 (range 641–13,833 mGy·cm2). The estimated effective dose (EED) was significantly lower with the LDCT scan (p < 0.001). The median EED was 4.93 and 1.90 mSv for radiographs and LDCT, respectively. Significantly better identification of the abdominal position of the distal shunt catheter was achieved with LDCT (p < 0.001). Simultaneously, significantly improved visualization of the entire shunt system was realized with this technique (p < 0.001). On the contrary, identification of the valve settings was significantly worse with LDCT (p < 0.001).CONCLUSIONSWhole-body LDCT scanning allows good visualization of the distal catheter after VP shunt placement. Despite the fact that only a rough estimation of effective doses is possible in a direct comparison of LDCT and radiography, the data showed that shunt assessment via LDCT does not lead to greater radiation exposure. Thus, especially in difficult anatomical conditions, as in patients who have undergone multiple intraabdominal surgeries, have a high BMI, or are immobile, the use of LDCT shunt evaluation has high clinical value. Further data are needed to determine the value of LDCT for the evaluation of complications or radiation dose in pediatric patients.

CT dosimetry at the Australian Synchrotron for 25–100 keV photons and 35–160 mm-diameter biological specimens

2019 ◽  
Vol 26 (2) ◽  
pp. 517-527
Author(s):  
Stewart Midgley ◽  
Nanette Schleich ◽  
Alex Merchant ◽  
Andrew Stevenson
Keyword(s):  
Effective Dose ◽  
Beam Quality ◽  
Absorbed Dose ◽  
Body Region ◽  
Average Dose ◽  
Dose Length Product ◽  
Organ Doses ◽  
Ct Dose ◽  
Radiation Output ◽  
Ct Dosimetry

The dose length product (DLP) method for medical computed tomography (CT) dosimetry is applied on the Australian Synchrotron Imaging and Medical Beamline (IMBL). Beam quality is assessed from copper transmission measurements using image receptors, finding near 100% (20 keV), 3.3% (25 keV) and 0.5% (30–40 keV) relative contributions from third-harmonic radiation. The flat-panel-array medical image receptor is found to have a non-linear dose response curve. The amount of radiation delivered during an axial CT scan is measured as the dose in air alone, and inside cylindrical PMMA phantoms with diameters 35–160 mm for mono-energetic radiation 25–100 keV. The radiation output rate for the IMBL is comparable with that used for medical CT. Results are presented as the ratios of CT dose indices (CTDI) inside phantoms to in air with no phantom. Ratios are compared for the IMBL against medical CT where bow-tie filters shape the beam profile to reduce the absorbed dose to surface organs. CTDI ratios scale measurements in air to estimate the volumetric CTDI representing the average dose per unit length, and the dose length product representing the absorbed dose to the scanned volume. Medical CT dose calculators use the DLP, beam quality, axial collimation and helical pitch to estimate organ doses and the effective dose. The effective dose per unit DLP for medical CT is presented as a function of body region, beam energy and sample sizes from neonate to adult.

scholarly journals Whole-Body Low-Dose Computed Tomography and Advanced Imaging Techniques for Multiple Myeloma Bone Disease

2014 ◽  
Vol 20 (23) ◽  
pp. 5888-5897 ◽  
Author(s):  
Matthew J. Pianko ◽  
Evangelos Terpos ◽  
G. David Roodman ◽  
Chaitanya R. Divgi ◽  
Sonja Zweegman ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Multiple Myeloma ◽  
Bone Disease ◽  
Low Dose ◽  
Imaging Techniques ◽  
Whole Body ◽  
Advanced Imaging ◽  
Myeloma Bone Disease ◽  
Low Dose Computed Tomography

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

2019 ◽  
Vol 25 (1) ◽  
pp. 51-55 ◽  
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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