scholarly journals Optimisation of T2 and T2* sequences in MRI for better quantification of iron on transfused dependent sickle cell patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Azza Ahmed ◽  
Amani Baldo ◽  
A. Sulieman ◽  
Hind Mirghani ◽  
Fouad A. Abolaban ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Acquisition Time ◽  
Thickness Variation ◽  
Slice Thickness ◽  
Pixel Size ◽  
Significant Difference ◽  
Repetition Time

AbstractThis work aimed to investigate the effect of different shim techniques, voxel sizes, and repetition time (TR) on using theT2 and T2* sequences to determine their optimum settings to investigate the quantification of iron in transfused dependent sickle cell patients. The effect of each of these parameters was investigated on phantoms of different Gadolinium (Gd) concentrations, on 10 volunteers and 25 patients using a1 5T MRI Philips scanner. No significant difference between the three shim techniques was noticed in either T2 or T2* sequence measurements. Pixel sizes of 1 × 1 and 2 × 2 mm provided optimum results for T2 measurements. At 1 × 1 mm pixel size the T2* measurements experienced less error in measurements than the size of 2.5 × 2.5 mm used in the literature. Even though the slice thickness variation did not provide any changes in T2 measurements, the 12 mm provided optimum T2* measurements. TR variation did not yield significant changes on either T2 or T2* measurements. These results indicate that both T2 and T2* sequences can be further improved by providing more reliable measurements and reducing acquisition time.

scholarly journals Analisis Variasi Slice Thickness Terhadap Informasi Anatomi Potongan Axial Pada Pemeriksaan MSCT Cervical Pada Kasus Trauma

2020 ◽  
Vol 6 (2) ◽  
pp. 91-95
Author(s):  
Rizki Aditya Nugroho ◽  
Jeffri Ardiyanto ◽  
Sigit Wijokongko
Keyword(s):  
Cervical Spine ◽  
Spinous Process ◽  
Transverse Process ◽  
Thickness Variation ◽  
Slice Thickness ◽  
Trauma Patients ◽  
Significant Difference ◽  
One Step ◽  
The Difference ◽  
Anatomic Information

Background: One step to create a good image is by doing slice thickness reconstruction. Slice thickness is thick slices or pieces of the object checked out. The examination procedure of MSCT in case of Cervical trauma in Radiology Installation RSUD Tugurejo Semarang using slice thickness 3 mm. This contrasts with Seeram (2016), which explained that the examination of adult MSCT Cervical Spine using slice thickness between 1-2 mm. This research aims to know the difference of anatomic information resulted by 5 slice thickness variation in MSCT Cervical Spine and to find out which slice thickness can provide optimum anatomic information.Methods: The type of this research is quantitative with an experimental approach. Data is performed by reconstructing the 5 images of MSCT cervical of trauma patients using 5 slice thickness variation which is 1 mm, 1.5 mm, 2 mm, 2.5 mm and 3 mm. The final images are evaluated by two Respondents to see the differences in anatomic information and then analyzed by using a different test (Friedman Test) from the SPSS version 24.0.Results: The results showed there is a  significant difference in anatomic information on the corpus, lamina, spinous process, transverse process and fragment fracture between variations in slice thickness of 1 mm, 1.5 mm, 2 mm, 2.5 mm, and 3 mm on the MSCT Cervical examination with a significance value of 0,000 or p 0.05.Conclusion: The most optimal slice thickness to provide anatomic information on the cervical MSCT examination is 1 mm slice thickness with a mean rank value of 3.64.

Some Quantification Problems in Parallel EELS Images

1990 ◽  
Vol 48 (2) ◽  
pp. 36-37
Author(s):  
G. Botton ◽  
G. L’Espérance ◽  
M.D. Ball ◽  
C.E. Gallerneault
Keyword(s):  
Electron Microscope ◽  
Imaging System ◽  
Signal To Noise Ratio ◽  
Scanning Transmission Electron Microscope ◽  
Acquisition Time ◽  
Thickness Variation ◽  
Transmission Electron ◽  
Distribution Of Elements ◽  
Scanning Transmission ◽  
Present Distribution

The recently developed parallel electron energy loss spectrometers (PEELS) have led to a significant reduction in spectrum acquisition time making EELS more useful in many applications in material science. Dwell times as short as 50 msec per spectrum with a PEELS coupled to a scanning transmission electron microscope (STEM), can make quantitative EEL images accessible. These images would present distribution of elements with the high spatial resolution inherent to EELS. The aim of this paper is to briefly investigate the effect of acquisition time per pixel on the signal to noise ratio (SNR), the effect of thickness variation and crystallography and finally the energy stability of spectra when acquired in the scanning mode during long periods of time.The configuration of the imaging system is the following: a Gatan PEELS is coupled to a CM30 (TEM/STEM) electron microscope, the control of the spectrometer and microscope is performed through a LINK AN10-85S MCA which is interfaced to a IBM RT 125 (running under AIX) via a DR11W line.

T1 Relaxation Time of Achilles Tendon at 3 Tesla with Special Reference to Relevant Clinical Score: A Preliminary Study

2020 ◽  
Vol 16 (2) ◽  
pp. 164-173
Author(s):  
Zeineb Tbini ◽  
Mokhtar Mars ◽  
Mouna Bouaziz
Keyword(s):  
Relaxation Time ◽  
Achilles Tendon ◽  
Clinical Score ◽  
3 Tesla ◽  
Acquisition Time ◽  
Short Term ◽  
T1 Relaxation Time ◽  
T1 Relaxation ◽  
Spin Echo Sequence ◽  
Significant Difference

Purpose: The purpose of this study was to investigate T1 relaxation time of the human Achilles tendon, to test its short-term repeatability as well as the minimal detectable change, and to assess the extent that correlate with clinical symptoms. Methods: Twenty asymptomatic volunteers and eighteen patients with clinically and sonographically confirmed tendinopathy were scanned for ankle using a 3 Tesla (T) MR scanner. T1 maps were calculated from a variable flip angle gradient echo Ultra-short echo time sequence (VFA-GE UTE) and inversion recovery spin echo sequence (IR-SE) using a self-developed matlab algorithm in three regions of interest of Achilles Tendon (AT). Signal to Noise Ratio (SNR) between the two sequences was evaluated. INTRA-class Correlation Coefficient (ICC), Coefficient of Variation (CV) and the Least Significant Change (LSC) were calculated, to test short-term repeatability of T1. Subjects were assessed by the VISA-A clinical score. P values less than 0.005 were considered statistically significant. Results: Mean T1 values were 427.09 ± 53.37 ms and 528.70 ± 103.50 ms using IR-SE sequence and 575.43 ± 110.60 ms and 875.81 ± 425.77 ms with VFA-GE UTE sequence in the whole AT for volunteers and patients, respectively. : T1 values showed a significant difference between volunteers and patients (P=0.001). Regional variation of T1 in healthy and tendinopathic AT were greater for VFA-GE UTE sequence than for IR-SE sequence. VFA-GE UTE sequence showed clearly higher SNR compared to IR-SE sequence. Short-term repeatability of T1 values for volunteers showed an LSC of 22% and 14% for IR-SE sequence and VFA-GE UTE sequence, respectively. For patients, LSC was 14% and 5% for IR-SE sequence and VFA-GE UTE sequence, respectively. There was no correlation between T1 and VISA-A clinical score (p>0.005). Conclusion: VFA-GE UTE sequence used for T1 mapping calculation demonstrated short acquisition time and clearly high SNR. Results revealed that T1 relaxation time can be used as a biomarker to differentiate between healthy and pathologic Achilles tendon. However, T1 showed no correlation with the VISA-A clinical score.

scholarly journals Image Quality Differences In CT Scan Thorax By Using Slice Thickness Variation

2017 ◽  
Vol 8 (2) ◽  
pp. 87-91
Author(s):  
Samsun Samsun ◽  
Legia Prananto ◽  
Novita Wulandari
Keyword(s):  
Image Quality ◽  
Ct Scan ◽  
Spatial Resolution ◽  
Optimal Parameter ◽  
Thickness Variation ◽  
Slice Thickness ◽  
Picture Quality ◽  
Thorax Ct ◽  
Research Show ◽  
Selection Of

The picture quality get from CT Scan of Thorax which required optimal parameter selection that’s right, one of them the selection of slice thickness. The method taken from theses that have been publish in the year 2013. The results of the research show the percentage of the value of the average spatial resolution of 2.5 mm slice thickness is (33.3%), noise (17.8%), artefact (1%). On the thickness of the slices 5 mm spatial resolution is (17%), noise (8.9%), artefacts (0%). On the thickness of slices of 7.5 mm spatial resolution is (8.9%), noise (11.1%), artefacts (53.3%). While the thickness of the slices the spatial resolution is 10 mm (8.9%), noise (22.2%), artefacts (68.9%). Based on the research results obtained the conclusion that thickness 2.5 mm slices on Thorax CT-Scan images produce better picture quality than with the thickness of the slices 5 mm, 7.5 mm, 10 mm, because the spatial resolution is more clear so as to reduce noise and artifacts.

scholarly journals Pregnancies and Neonatal Outcomes in Patients with Sickle Cell Disease (SCD): Still a (High-)Risk Constellation?

2021 ◽  
Vol 11 (9) ◽  
pp. 870
Author(s):  
Pia Proske ◽  
Laura Distelmaier ◽  
Carmen Aramayo-Singelmann ◽  
Nikolaos Koliastas ◽  
Antonella Iannaccone ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Neonatal Outcomes ◽  
University Hospital ◽  
High Rate ◽  
Successful Outcome ◽  
Acute Chest Syndrome ◽  
Cell Disease ◽  
Significant Difference ◽  
Tract Infections

Background: This monocentric study conducted at the University Hospital of Essen aims to describe maternal and fetal/neonatal outcomes in sickle cell disease (SCD) documented between 1996 to 2021 (N = 53), reflecting the largest monocentric analysis carried out in Germany. Methods/Results: 46 pregnancies in 22 patients were followed. None of the patients died. In total, 35% (11/31) of pregnancies were preterm. 15 pregnancies in eight patients were conceived on hydroxycarbamide (HC), of which nine had a successful outcome and three were terminated prematurely. There was no difference regarding the rate of spontaneous abortions in patients receiving HC compared to HC-naive patients prior to conception. In patients other than HbS/C disease, pregnancies were complicated by vaso-occlusive crises (VOCs)/acute pain crises (APCs) (96%, 23/24); acute chest syndrome (ACS) (13%, 3/24), transfusion demand (79%, 19/24), urinary tract infections (UTIs) (42%, 10/24) and thromboembolic events (8%, 2/24). In HbS/C patients complications included: VOCs/APCs (43%, 3/7; ACS: 14%, 1/7), transfusion demand (14%, 1/7), and UTIs (14%, 1/7). Independent of preterm deliveries, a significant difference with respect to neonatal growth in favor of neonates from HbS/C mothers was observed. Conclusion: Our data support the results of previous studies, highlighting the high rate of maternal and fetal/neonatal complications in pregnant SCD patients.

Abstract 342: A Description of Cardiac Outcomes in Patients With Sickle Cell Trait and Chronic Kidney Disease: Evaluated in a National Inpatient Data Sample

2020 ◽  
Vol 13 (Suppl_1) ◽  
Author(s):  
Samuel I Ogbuchi ◽  
Temidayo Abe ◽  
Kapil Bhatia ◽  
Leondus S McIver ◽  
Michelle Lee ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Risk Factor ◽  
Kidney Disease ◽  
Sickle Cell ◽  
Sickle Cell Trait ◽  
Sudden Cardiac Arrest ◽  
Protective Role ◽  
Significant Difference ◽  
Inflammatory State ◽  
Overall Mortality

Introduction: Sickle cell trait (SCT) is an independent risk factor for chronic kidney disease (CKD). CKD is a well-established risk factor for progressive cardiovascular dysfunction. Sickle Cell trait has been noted to promote a persistent systemic pro-inflammatory state. This pro-inflammatory state could potentially increase the risk of systemic endothelial dysfunction when accompanied with other cardiotoxic conditions. We aim to investigate cardiovascular outcomes in patients with SCT and CKD, compared to SCT alone. Methods: Patients with CKD were identified in the National Inpatient Sample (NIS) database 2016 using the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), and subsequently were divided into two groups, those with and without SCT. Both population sets were paired using 1:1 propensity score matching based on Age, Sex and co-morbidities to address potential confounding factors. Outcomes of interest were overall mortality, rates of stroke, sudden cardiac arrest (SCA) and cardiomyopathy. Results: Mean age of patients with CKD alone was 72.98 ± 13.2 years, while for CKD and SCT 56.68 ± 17.3 years. There was no significant difference between the two group in the rates of stroke (1.3% vs 1.0%; P= 0.125), and SCA (1.0% vs 1.1%; P= 0.841). Overall mortality (5.7% vs 2.2%; P<0.0001) and rates of cardiomyopathy (10.1% vs 2.9%; P<0.0001) were significantly lower in patients with CKD and SCT, compared to CKD alone. Multivariate logistic regression followed a similar trend, compared to those with CKD alone, the adjusted odds ratio (aOR) for overall mortality aOR; 0.625 (0.372-1.049) and cardiomyopathy aOR; 0.451 (0.293-0.696) were significantly lower in patients with CKD and SCT. Conclusion: Compared to patients with CKD alone, those with CKD and SCT have a lower risk for overall mortality and cardiomyopathy. Further studies are needed to replicate this finding and look at the possible protective role of SCT in patients with CKD.

Evaluation of Hearing and Balance Functions of Patients with Sickle Cell Anemia

2018 ◽  
Vol 23 (2) ◽  
pp. 122-125 ◽  
Author(s):  
Elif Tugba Sarac ◽  
Bilgehan Boke ◽  
Semsettin Okuyucu
Keyword(s):  
Hearing Loss ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Pure Tone ◽  
Mixed Type ◽  
Normal Hearing ◽  
Spontaneous Nystagmus ◽  
Control Group ◽  
Hearing Thresholds ◽  
Significant Difference

Introduction: Sickle cell anemia is a disease characterized by a wide vaso-occlusive incident from micro-vascular incident to muscularactivity. The cochlear function can also get affected by this vaso-occlusion. Objective: It is aimed at determining what kind of effects sickle cell anemia has on hearing and balance system. Methods: This study has been conducted on 46 patients with sickle cell anemia and 45 healthy individuals. For all participants, their pure tone hearing thresholds and videonystagmography (VNG) findings have been determined in 17 frequencies between 125–16.000 Hz. Results: All hearing thresholds between 125 and 16,000 Hz, pure tone averages of patients with sickle cell anemia have been found statistically significant to be higher than the corresponding values in the control group(p < 0.05). The normal hearing rate of patients with sickle cell anemia has been determined to be 71.1% conductive hearing loss (CHL) to be 4.4%, sensorineural hearing loss (SNHL) to be 22.2%, and mixed type hearing loss to be 2.2% in right ear; the normal hearing rate has been determined to be 71.1%, CHL to be 2.2%, SNHL to be 22.2%, and mixed type hearing loss to be 4.4% in left ear. Statistically significant difference has not been found between head shake, spontaneous nystagmus, optokinetic, tracking test batteries, static and dynamic positional tests used in VNG, saccade accuracy and saccade peak velocity, which are saccadic test findings of 2 groups. However, saccadic latency, which is a saccadic test finding, has been determined to be longer in patients with sickle cell anemia in comparison to the control group. Conclusion: While sickle cell anemia causes hearing deficits, it does not have any effect on the central or peripheral vestibular system.

Evaluation of Intravenous Diphenhydramine Use in Patients with Sickle Cell Vaso-Occlusive Crisis

2020 ◽  
pp. 001857872095417
Author(s):  
Katherine Rector ◽  
Shelby Merchant ◽  
Rachel Crawford ◽  
Justin R. Arnall ◽  
James Symanowski ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Length Of Stay ◽  
Sickle Cell ◽  
Cell Disease ◽  
Median Length ◽  
Significant Difference ◽  
Oral Group ◽  
Icd 10 ◽  
Secondary Endpoints ◽  
Group 2

Purpose: To compare the incidence of oversedation between oral and parenteral diphenhydramine therapy for treatment of opioid-induced pruritus in patients with sickle cell disease vaso-occlusive crisis (SCD VOC). Methods: This retrospective, single-center, cohort study included patients greater than or equal to 18 years old with sickle cell disease admitted for vaso-occlusive crisis who received either intravenous or oral diphenhydramine for opioid-induced pruritus. Patients were identified through ICD-9 and ICD-10 codes from June 1, 2016 through July 1, 2017. Rates of oversedation were compared between the 2 formulations. Secondary endpoints included length of stay, amount and duration of diphenhydramine, rate of acute chest and indication for IV therapy. Results: Fifty unique patients were included in the analysis representing 121 admissions. Seven patients received both formulations on separate admissions and were included in both groups. Twenty-nine percent of patients in the IV diphenhydramine group experienced oversedation (12/42) versus 13% in the oral diphenhydramine group (2/15, P = .312). The average number of admissions was significantly higher in the IV versus oral group (2.45 vs 1.20; P = .005) with average and median length of stay also significantly higher in the IV versus oral group (30.57, 16.0 vs 10.67, 10.0; P = .003). Conclusion: While there was no statistically significant difference in the rates of oversedation with use of IV versus oral diphenhydramine formulations, patients with SCD VOC who received IV diphenhydramine had more frequent admissions and a longer length of stay. Clinicians may consider oral diphenhydramine preferentially in appropriate patients over IV administration.

Whole Blood Tissue Factor Procoagulant Activity Is Elevated in Patients With Sickle Cell Disease

Blood ◽  
1998 ◽  
Vol 91 (11) ◽  
pp. 4216-4223 ◽  
Author(s):  
Nigel S. Key ◽  
Arne Slungaard ◽  
Luke Dandelet ◽  
Stephen C. Nelson ◽  
Christopher Moertel ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Tissue Factor ◽  
Mononuclear Cell ◽  
Sickle Cell ◽  
Whole Blood ◽  
Procoagulant Activity ◽  
Cell Disease ◽  
Blood Samples ◽  
Significant Difference ◽  
Whole Blood Samples

Abstract We developed a simple assay for the measurement of tissue factor procoagulant activity (TF PCA) in whole blood samples that avoids the need for mononuclear cell isolation. This method combines convenience of sample collection and processing with a high degree of sensitivity and specificity for TF. Using this method, we have determined that TF PCA is detectable in whole blood samples from normal individuals, which is itself a novel observation. Essentially all PCA could be shown to be localized in the mononuclear cell fraction of blood. Compared with controls, whole blood TF levels were significantly (P &lt; .000001) elevated in patients with sickle cell disease (SCD), regardless of the subtype of hemoglobinopathy (SS or SC disease). No significant difference in TF PCA was observed between patients in pain crisis compared with those in steady-state disease. Because TF functions as cofactor in the proteolytic conversion of FVII to FVIIa in vitro, it was expected that an increase in circulating TF PCA would lead to an increased in vivo generation of FVIIa. On the contrary, FVIIa levels were actually decreased in the plasma of patients with SCD. Plasma TF pathway inhibitor (TFPI) antigen levels were normal in SCD patients, suggesting that accelerated clearance of FVIIa by the TFPI pathway was not responsible for the reduced FVIIa levels. We propose that elevated levels of circulating TF PCA may play an important role in triggering the activation of coagulation known to occur in patients with SCD. Because TF is the principal cellular ligand for FVIIa, it is possible that increased binding to TF accounts for the diminished plasma FVIIa levels.

scholarly journals Evaluation of the concentration of malondialdehyde and nitrite in patients with sickle cell anemia treated or not with hydroxyurea

2010 ◽  
Vol 8 (4) ◽  
pp. 414-418 ◽  
Author(s):  
Darcielle Bruna Dias Elias ◽  
Rivelilson Mendes de Freitas ◽  
Romélia Pinheiro Gonçalves ◽  
Hemerson Yuri Ferreira Magalhães ◽  
Jacqueline Holanda de Sousa ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Serum Levels ◽  
The Other ◽  
Control Group ◽  
Clinical Variables ◽  
Short Period ◽  
Significant Difference ◽  
Group 2 ◽  
Group 1

ABSTRACT Objective: To determine the serum levels of malondialdehyde and nitrite in patients with sickle cell anemia treated or not with hydroxyurea in outpatient's setting. Methods: Of the 65 patients with sickle cell anemia selected for the study, 51 were not treated with hydroxyurea (Group 1), 14 made chronic use of hydroxyurea (Group 2) and 20 individuals had no hemoglobinopathies (Control Group). Results: The Control Group had a lower and more homogeneous concentration of malondialdehyde levels as compared to the other groups. The results of Groups 1 and 2 showed increased values of malondialdehyde levels when compared to the Control Group. Considering the values of Groups 1 and 2, there were no significant changes in the malondialdehyde levels. There was no significant difference in the serum levels of nitrite between the groups. Group 2 presented a statistically significant correlation between serum malondialdehyde levels and the clinical variables investigated. In turn, Group 1 showed correlation only with occurrence of three or more vaso-occlusive crises. There was no correlation between nitrite levels and the clinical variables. Conclusion: The results revealed that during the pathogenesis of sickle cell anemia, an increase in lipid peroxidation was observed. On the other hand, no changes in oxidative parameters were detected during treatment with hydroxyurea, probably due to the short period of treatment of the patients studied.

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