scholarly journals Development and implementation of an ultralow-dose CT protocol for the assessment of cerebrospinal shunts in adult hydrocephalus

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
David J. Ryan ◽  
Richard G. Kavanagh ◽  
Stella Joyce ◽  
Mika O’Callaghan Maher ◽  
Niamh Moore ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Radiation Dose ◽  
Shunt Malfunction ◽  
Whole Body ◽  
Anthropomorphic Phantom ◽  
Ultralow Dose ◽  
Ct Protocol ◽  
Ethical Approval ◽  
Cumulative Radiation Dose ◽  
Shunt Series

Abstract Background Cerebrospinal fluid shunts in the treatment of hydrocephalus, although associated with clinical benefit, have a high failure rate with repeat computed tomography (CT) imaging resulting in a substantial cumulative radiation dose. Therefore, we sought to develop a whole-body ultralow-dose (ULD) CT protocol for the investigation of shunt malfunction and compare it with the reference standard, plain radiographic shunt series (PRSS). Methods Following ethical approval, using an anthropomorphic phantom and a human cadaveric ventriculoperitoneal shunt model, a whole-body ULD-CT protocol incorporating two iterative reconstruction (IR) algorithms, pure IR and hybrid IR, including 60% filtered back projection and 40% IR was evaluated in 18 adult patients post new shunt implantation or where shunt malfunction was suspected. Effective dose (ED) and image quality were analysed. Results ULD-CT permitted a 36% radiation dose reduction (median ED 0.16 mSv, range 0.07–0.17, versus 0.25 mSv (0.06–1.69 mSv) for PRSS (p = 0.002). Shunt visualisation in the thoracoabdominal cavities was improved with ULD-CT with pure IR (p = 0.004 and p = 0.031, respectively) and, in contrast to PRSS, permitted visualisation of the entire shunt course (p < 0.001), the distal shunt entry point and location of the shunt tip in all cases. For shunt complications, ULD-CT had a perfect specificity. False positives (3/22, 13.6%) were observed with PRSS. Conclusions At a significantly reduced radiation dose, whole body ULD-CT with pure IR demonstrated diagnostic superiority over PRSS in the evaluation of cerebrospinal fluid shunt malfunction.

scholarly journals Effects of exposure to low-dose ionizing radiation on changing platelets: a prospective cohort study

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Ning Liu ◽  
Yang Peng ◽  
Xinguang Zhong ◽  
Zheng Ma ◽  
Suiping He ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Dose Response ◽  
Low Dose ◽  
Linear Trend ◽  
Hematological Parameters ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Spline Models ◽  
Cumulative Radiation Dose

Abstract Background Numerous studies have concentrated on high-dose radiation exposed accidentally or through therapy, and few involve low-dose occupational exposure, to investigate the correlation between low-dose ionizing radiation and changing hematological parameters among medical workers. Methods Using a prospective cohort study design, we collected health examination reports and personal dose monitoring data from medical workers and used Poisson regression and restricted cubic spline models to assess the correlation between changing hematological parameters and cumulative radiation dose and determine the dose-response relationship. Results We observed that changing platelet of 1265 medical workers followed up was statistically different among the cumulative dose groups (P = 0.010). Although the linear trend tested was not statistically significant (Ptrend = 0.258), the non-linear trend tested was statistically significant (Pnon-linear = 0.007). Overall, there was a correlation between changing platelets and cumulative radiation dose (a change of βa 0.008 × 109/L during biennially after adjusting for gender, age at baseline, service at baseline, occupation, medical level, and smoking habits; 95% confidence interval [CI] = 0.003,0.014 × 109/L). Moreover, we also found positive first and then negative dose-response relationships between cumulative radiation dose and changing platelets by restricted cubic spline models, while there were negative patterns of the baseline service not less than 10 years (− 0.015 × 109/L, 95% CI = − 0.024, − 0.007 × 109/L) and radiation nurses(− 0.033 × 109/L, 95% CI = − 0.049, − 0.016 × 109/L). Conclusion We concluded that although the exposure dose was below the limit, medical workers exposed to low-dose ionizing radiation for a short period of time might have increased first and then decreased platelets, and there was a dose-response relationship between the cumulative radiation dose and platelets changing.

scholarly journals Simulated Radiation Dose Reduction in Whole-Body CT on a 3rd Generation Dual-Source Scanner: An Intraindividual Comparison

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Andreas S. Brendlin ◽  
Moritz T. Winkelmann ◽  
Phuong Linh Do ◽  
Vincent Schwarze ◽  
Felix Peisen ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Dose Reduction ◽  
Whole Body ◽  
Reference Standard ◽  
Diagnostic Confidence ◽  
Effective Radiation Dose ◽  
Intraindividual Comparison ◽  
Dual Source ◽  
Effective Radiation

To evaluate the effect of radiation dose reduction on image quality and diagnostic confidence in contrast-enhanced whole-body computed tomography (WBCT) staging. We randomly selected March 2016 for retrospective inclusion of 18 consecutive patients (14 female, 60 ± 15 years) with clinically indicated WBCT staging on the same 3rd generation dual-source CT. Using low-dose simulations, we created data sets with 100, 80, 60, 40, and 20% of the original radiation dose. Each set was reconstructed using filtered back projection (FBP) and Advanced Modeled Iterative Reconstruction (ADMIRE®, Siemens Healthineers, Forchheim, Germany) strength 1–5, resulting in 540 datasets total. ADMIRE 2 was the reference standard for intraindividual comparison. The effective radiation dose was calculated using commercially available software. For comparison of objective image quality, noise assessments of subcutaneous adipose tissue regions were performed automatically using the software. Three radiologists blinded to the study evaluated image quality and diagnostic confidence independently on an equidistant 5-point Likert scale (1 = poor to 5 = excellent). At 100%, the effective radiation dose in our population was 13.3 ± 9.1 mSv. At 20% radiation dose, it was possible to obtain comparably low noise levels when using ADMIRE 5 (p = 1.000, r = 0.29). We identified ADMIRE 3 at 40% radiation dose (5.3 ± 3.6 mSv) as the lowest achievable radiation dose with image quality and diagnostic confidence equal to our reference standard (p = 1.000, r > 0.4). The inter-rater agreement for this result was almost perfect (ICC ≥ 0.958, 95% CI 0.909–0.983). On a 3rd generation scanner, it is feasible to maintain good subjective image quality, diagnostic confidence, and image noise in single-energy WBCT staging at dose levels as low as 40% of the original dose (5.3 ± 3.6 mSv), when using ADMIRE 3.

Hematologic Toxicity of High-Dose Iodine-131–Metaiodobenzylguanidine Therapy for Advanced Neuroblastoma

2004 ◽  
Vol 22 (12) ◽  
pp. 2452-2460 ◽  
Author(s):  
Steven G. DuBois ◽  
Julia Messina ◽  
John M. Maris ◽  
John Huberty ◽  
David V. Glidden ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Radiation Dose ◽  
Red Cells ◽  
Whole Body ◽  
High Dose ◽  
Hematologic Toxicity ◽  
Severe Thrombocytopenia ◽  
Hematopoietic Stem ◽  
Iodine 131 ◽  
Mibg Therapy

Purpose Iodine-131–metaiodobenzylguanidine (131I-MIBG) has been shown to be active against refractory neuroblastoma. The primary toxicity of 131I-MIBG is myelosuppression, which might necessitate autologous hematopoietic stem-cell transplantation (AHSCT). The goal of this study was to determine risk factors for myelosuppression and the need for AHSCT after 131I-MIBG treatment. Patients and Methods Fifty-three patients with refractory or relapsed neuroblastoma were treated with 18 mCi/kg 131I-MIBG on a phase I/II protocol. The median whole-body radiation dose was 2.92 Gy. Results Almost all patients required at least one platelet (96%) or red cell (91%) transfusion and most patients (79%) developed neutropenia (< 0.5 × 103/μL). Patients reached platelet nadir earlier than neutrophil nadir (P < .0001). Earlier platelet nadir correlated with bone marrow tumor, more extensive bone involvement, higher whole-body radiation dose, and longer time from diagnosis to 131I-MIBG therapy (P ≤ .04). In patients who did not require AHSCT, bone marrow disease predicted longer periods of neutropenia and platelet transfusion dependence (P ≤ .03). Nineteen patients (36%) received AHSCT for prolonged myelosuppression. Of patients who received AHSCT, 100% recovered neutrophils, 73% recovered red cells, and 60% recovered platelets. Failure to recover red cells or platelets correlated with higher whole-body radiation dose (P ≤ .04). Conclusion These results demonstrate the substantial hematotoxicity associated with high-dose 131I-MIBG therapy, with severe thrombocytopenia an early and nearly universal finding. Bone marrow tumor at time of treatment was the most useful predictor of hematotoxicity, whereas whole-body radiation dose was the most useful predictor of failure to recover platelets after AHSCT.

Diagnostic challenges in neoplastic meningitis presenting as intracranial hypertension

2021 ◽  
Vol 14 (3) ◽  
pp. e238808
Author(s):  
Santosh Sriram Andugulapati ◽  
Akash Chheda ◽  
Karan Desai ◽  
Sangeeta Hasmukh Ravat
Keyword(s):  
Cerebrospinal Fluid ◽  
Intracranial Hypertension ◽  
Neoplastic Meningitis ◽  
Whole Body ◽  
Csf Cytology ◽  
Csf Analysis ◽  
Pet Ct ◽  
Pet Ct Scan ◽  
Systemic Malignancy

A diagnosis of idiopathic intracranial hypertension should be considered only after careful exclusion of all possible aetiologies. We report a case of neoplastic meningitis presenting as intracranial hypertension with inconclusive repeated cerebrospinal fluid (CSF) cytology and MRI of brain, emphasising the importance of meticulous CSF analysis and role of early whole-body PET–CT scan for diagnosis of systemic malignancy.

Neonatal digital chest radiography– should we be using additional copper filtration?

2021 ◽  
Author(s):  
Jenna Ruth Tugwell-Allsup ◽  
Rhys Wyn Morris ◽  
Kate Thomas ◽  
Richard Hibbs ◽  
Andrew England
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Detrimental Effect ◽  
Chest Imaging ◽  
Anthropomorphic Phantom ◽  
Visual Grading ◽  
X Ray ◽  
Visual Grading Analysis ◽  
Designed Experiment ◽  
Digital Chest

Objectives: Copper filtration removes lower energy X-ray photons, which do not enhance image quality but would otherwise contribute to patient dose. This study explores the use of additional copper filtration for neonatal mobile chest imaging. Methods: A controlled factorial-designed experiment was used to determine the effect of independent variables on image quality and radiation dose. These variables included: copper filtration (0Cu, 0.1Cu and 0.2Cu), exposure factors, SID and image receptor position (direct +tray). Image quality was evaluated using absolute visual grading analysis (VGA) and contrast-to-noise ratio (CNR) and entrance surface dose (ESD) was derived using an ionising chamber within the central X-ray beam. Results: VGA, CNR and ESD significantly reduced (p < 0.01) when using added copper filtration. For 0.1Cu, the percentage reduction was much greater for ESD (60%) than for VGA (14%) and CNR (20%), respectively. When compared to the optimal combinations of parameters for incubator imaging using no copper filtration, an increase in kV and mAs when using 0.1mmCu resulted in better image quality at the same radiation dose (direct) or, equal image quality at reduced dose (in-tray). The use of 0.1mmCu for neonatal chest imaging with a corresponding increase in kV and mAs is therefore recommended. Conclusions: Using additional copper filtration significantly reduces radiation dose (at increased mAs) without a detrimental effect on image quality. Advances in knowledge: This is the first study, using an anthropomorphic phantom, to explore the use of additional Cu for DR neonatal chest imaging and therefore helps inform practice to standardise and optimise this imaging examination.

scholarly journals Is nuclear medicine really safe?

2002 ◽  
Vol 45 (spe) ◽  
pp. 115-118
Author(s):  
Nicole Colas-Linhart
Keyword(s):  
Nuclear Medicine ◽  
Human Serum Albumin ◽  
Radiation Dose ◽  
Serum Albumin ◽  
Human Serum ◽  
Absorbed Dose ◽  
Cellular Level ◽  
Whole Body ◽  
Absorbed Doses ◽  
Standard Models

In nuclear medicine, radiation absorbed dose estimates calculated by standard models at the whole body or organ are very low. At cellular level, however, the heterogeneity of radionuclide distributions of radiation dose patterns may be significant. We present here absorbed doses at cellular level and evaluate their possible impact on the usually assumed risk/benefit relationships in nuclear medicine studies. The absorbed dose values calculated are surprisingly high, and are difficult to interpret. In the present study, we show calculated doses at the cellular level and discuss possible biological consequences, for two radiopharmaceuticals labelled with technetium-99m: human serum albumin microspheres used for pulmonary scintigrapies and HMPAO used to labelled leukocytes.

scholarly journals FREQUENCY OF INFECTION AFTER CEREBROSPINAL FLUID SHUNTING PROCEDURES

2020 ◽  
Author(s):  
Kashif Ramooz ◽  
Eesha Yaqoob ◽  
Nadeem Akhtar ◽  
Fraz Mehmood ◽  
Saad Javed
Keyword(s):  
Cerebrospinal Fluid ◽  
Age Distribution ◽  
Age Groups ◽  
Csf Shunts ◽  
Ethical Approval ◽  
The Central Nervous System ◽  
Rate Study ◽  
Cerebrospinal Fluid Shunting ◽  
Prolonged Hospital

ABSTRACTHydrocephalus is routinely treated by surgical procedures. Cerebrospinal fluid shunt placement is a critical therapeutic intervention for hydrocephalus.CSF shunting has multiple complications among which infection is very common. The major cause of morbidity and mortality in patients with CSF shunts is theinfection of the central nervous system (CNS).It can lead to prolonged hospital stay, increase the number of operative procedures 03 times more than then none infected cases and has twice the fatality rate. Study of such type of complication will help the patients to improve their health and also improve our sterilization techniques and reduce burden of hospital and patients expenditures. The objective of the study was to determine the frequency of infection after cerebrospinal fluid shunting procedures.Case series study was used as study design.Study was conducted from 10-2010 to 10-06-2011.One hundred and forty four patients with both genders of all age groups undergoing cerebrospinal fluid shunting, meeting inclusion and exclusion criteria, were selected for the present study after informed consent of patient or guardian and approval by the hospital ethical committee. Follow up was ensured by taking the telephonic contact and address of patient.Total no of patients were 144 among which, 89 were males and 55 were females. Age distribution was from 01 month to 75 years with the mean age of 15.280 and standard deviation was ± 20.450. Post-operative infection was present in 20(13.9%) patients.Author’s approvalAll the authors have seen the manuscript and approved it.Declaration of interestNoneConflict/Competing of InterestNone.Disclosure of FundingNone.Ethical ApprovalAttached

Triple rule-out CT angiography protocol with restricting field of view for detection of pulmonary thromboembolism and aortic dissection in emergency department patients: simulation of modified CT protocol for reducing radiation dose

2016 ◽  
Vol 58 (5) ◽  
pp. 521-527 ◽  
Author(s):  
Hyun Su Kim ◽  
Sung Mok Kim ◽  
Min Jae Cha ◽  
Yoo Na Kim ◽  
Hae Jin Kim ◽  
...  
Keyword(s):  
Emergency Department ◽  
Radiation Dose ◽  
Aortic Dissection ◽  
Ct Angiography ◽  
Pulmonary Thromboembolism ◽  
Acute Chest Pain ◽  
Field Of View ◽  
Ct Protocol ◽  
Triple Rule Out ◽  
Rule Out

Background Triple rule-out computed tomography (TRO CT) is a CT protocol designed to simultaneously evaluate the coronary, aorta, and pulmonary arteries. Purpose To evaluate potential diagnostic performance of TRO CT with restricted volume coverage for detection of pulmonary thromboembolism (PTE) and aortic dissection (AD). Material and Methods This study included 1224 consecutive patients with acute chest pain who visited the emergency department and underwent TRO CT using a 128-slice dual-source CT. Image data were reconstructed according to the display field of view (DFOV) of coronary CT angiography (CCTA) and TRO CT protocols in each patient. The presence of PTE and AD was evaluated by independent observers in each DFOV. The radiation dose was calculated to evaluate the potential benefits by restricting z-axis coverage to cardiac scan range instead of the whole thorax. Results Among all patients, 22 cases with PTE (1.9%) and nine cases with AD (0.8%) were found. Except for one PTE case, all cases were detected on both DFOV of TRO CT and CCTA. Mean effective dose for evaluation of entire thorax and cardiac scan coverage were 5.9 ± 1.1 mSv and 3.5 ± 0.7 mSv, respectively. Conclusion Isolated PTE and AD outside the CCTA DFOV rarely occur. Therefore, modified TRO CT protocol using cardiac scan coverage can be adopted to detect PTE and AD with reduced radiation dose.

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