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1.
BMC Gastroenterol ; 24(1): 186, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38807055

RESUMO

BACKGROUND: Egypt faces a significant public health burden due to chronic liver diseases (CLD) and peptic ulcer disease. CLD, primarily caused by Hepatitis C virus (HCV) infection, affects over 2.9% of the population nationwide, with regional variations. Steatotic liver disease is rapidly emerging as a significant contributor to CLD, especially in urban areas. Acid-related disorders are another widespread condition that can significantly impact the quality of life. These factors and others significantly influence the indications and findings of gastrointestinal endoscopic procedures performed in Egypt. AIM: We aimed to evaluate the clinico-demographic data, indications, and endoscopic findings in Egyptian patients undergoing gastrointestinal endoscopic procedures in various regions of Egypt. METHODS: This study employed a retrospective multicenter cross-sectional design. Data was collected from patients referred for gastrointestinal endoscopy across 15 tertiary gastrointestinal endoscopy units in various governorates throughout Egypt. RESULTS: 5910 patients aged 38-63 were enrolled in the study; 75% underwent esophagogastroduodenoscopy (EGD), while 25% underwent a colonoscopy. In all studied patients, the most frequent indications for EGD were dyspepsia (19.5%), followed by hematemesis (19.06%), and melena (17.07%). The final EGD diagnoses for the recruited patients were portal hypertension-related sequelae (60.3%), followed by acid-related diseases (55%), while 10.44% of patients had a normally apparent endoscopy. Male gender, old age, and the presence of chronic liver diseases were more common in patients from upper than lower Egypt governorates. Hematochezia (38.11%) was the most reported indication for colonoscopy, followed by anemia of unknown origin (25.11%). IBD and hemorrhoids (22.34% and 21.86%, respectively) were the most prevalent diagnoses among studied patients, while normal colonoscopy findings were encountered in 18.21% of them. CONCLUSION: This is the largest study describing the situation of endoscopic procedures in Egypt. our study highlights the significant impact of regional variations in disease burden on the utilization and outcomes of GI endoscopy in Egypt. The high prevalence of chronic liver disease is reflected in the EGD findings, while the colonoscopy results suggest a potential need for increased awareness of colorectal diseases.


Assuntos
Endoscopia Gastrointestinal , Humanos , Masculino , Feminino , Egito/epidemiologia , Estudos Transversais , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto , Endoscopia Gastrointestinal/estatística & dados numéricos , Gastroenteropatias/epidemiologia , Gastroenteropatias/diagnóstico , Endoscopia do Sistema Digestório/estatística & dados numéricos , Hepatopatias/epidemiologia , Dispepsia/epidemiologia , Dispepsia/etiologia , Colonoscopia/estatística & dados numéricos , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/epidemiologia
2.
Int Nurs Rev ; 2024 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-38217403

RESUMO

AIM: This study aims to explore the relationship between collaborative leadership and nurses' productive work performance as well as the mediating role of nurses' innovative behavior in this relationship. BACKGROUND: Collaborative leadership is an imperative necessity in the contemporary turbulent healthcare environment as it provides a collaborative atmosphere where innovative behavior and productive performance of nurses are fostered, hence moving healthcare organizations toward competitiveness and sustainability. METHOD: A cross-sectional descriptive correlational exploratory research design was used to conduct the study. Data were collected from 550 nurses recruited from three large university hospitals in Alexandria, Egypt, using three instruments, namely, interprofessional collaborative leadership in healthcare teams scale, productive work performance questionnaire, and innovative behavior inventory. The instruments of the study are Likert-type questionnaires through which nurses' perspectives regarding study variables were investigated. We used descriptive statistics, inferential statistics as well as structured equation modeling (SEM). RESULTS: SEM revealed that collaborative leadership accounted for 83% of the variance of individual productive work performance and 77% of the variance of nurses' innovative behavior. Moreover, nurses' innovative behavior partially mediates the relationship between collaborative leadership and their productive work performance. CONCLUSION: Collaborative leadership practices are powerful strategies to enhance the innovative behavior of nurses and sustain their productive work performance. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Fostering a collaborative atmosphere in workplace is mandatory for nurses' innovativeness. Replacing hierarchal leadership styles with collaborative ones is a promising strategy to enhance the productive performance of nurses. Healthcare managers and leaders could cultivate an interprofessional collaborative culture in the workplace in order to sustain productivity and eradicate counterproductive work behaviors among healthcare providers.

3.
J Mol Cell Cardiol ; 185: 1-12, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37839656

RESUMO

We recently described a subgroup of autopsied COVID-19 subjects (∼40%), termed 'profibrotic phenotype,' who exhibited clusters of myofibroblasts (Mfbs), which were positive for the collagen-specific chaperone heat shock protein 47 (HSP47+) in situ. This report identifies increased, localized (hot spot restricted) expression of αSMA, COLα1, POSTN and FAP supporting the identity of HSP47+ cells as myofibroblasts and characterizing a profibrotic extracellular matrix (ECM) phenotype. Coupled with increased GRP78 in COVID-19 subjects, these data could reflect induction of the unfolded protein response for mitigation of proteostasis (i.e., protein homeostasis) dysfunction in discrete clusters of cells. ECM shifts in selected COVID-19 subjects occur without significant increases in either global trichrome positive staining or myocardial injury based quantitively on standard H&E scoring. Our findings also suggest distinct mechanism(s) for ECM remodeling in the setting of SARS-CoV-2 infection. The ratio of CD163+/CD68+ cells is increased in hot spots of profibrotic hearts compared with either controls or outside of hot spots in COVID-19 subjects. In sum, matrix remodeling of human COVID-19 hearts in situ is characterized by site-restricted profibrotic mediated (e.g., HSP47+ Mfbs, CD163+ Mφs) modifications in ECM (i.e., COLα1, POSTN, FAP), with a strong correlation between COLα1 and HSP47+cells within hot spots. Given the established associations of viral infection (e.g., human immunodeficiency virus; HIV), myocardial fibrosis and sudden cardiac death, early screening tools (e.g., plasma biomarkers, noninvasive cardiac magnetic resonance imaging) for diagnosis, monitoring and treatment of fibrotic ECM remodeling are warranted for COVID-19 high-risk populations.


Assuntos
COVID-19 , Miofibroblastos , Humanos , Miofibroblastos/metabolismo , COVID-19/patologia , SARS-CoV-2 , Coração , Proteínas de Choque Térmico HSP47/genética , Proteínas de Choque Térmico HSP47/metabolismo , Fibrose
4.
BMC Nurs ; 22(1): 429, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37964275

RESUMO

BACKGROUND: Mentorship is a vital part of the nursing profession to improve role transition, job satisfaction, and job retention while facilitating socialization, emotional well-being, and the acquisition of new skills. AIM: The present study aimed to evaluate the effect of an educational program about mentorship competencies on nurse mentors' performance at Port Said Healthcare Authority hospitals. METHODS: A quasi-experimental study design (pre-test and post-test one group) was used to conduct the study at seven Healthcare Authority hospitals in Port Said Governorate, Egypt. The study subjects were consisted of a purposive sample of 30 nurse mentors and 60 intern nursing students. Data were collected using three tools consisted of the Mentor Knowledge Questionnaire, Mentor Competencies Instrument (MCI), and Nurse Mentor Performance Assessment. Data analysis was performed using SPSS version 20, Student's t-test was used to measure differences between the pretest and post-test, and Qualitative categorical variables were compared using the chi-square test. A significant level value was considered when the p-value ≤ 0.05, and Cohen's d was used to measure the effect size. RESULTS: the post-test scores of mentorship competencies and performance after implementation of the educational program significantly improved in the studied nurse mentors 56.1 ± 13.2, 60.5 ± 4.9 compared with pre-test scores with 37.1 ± 4.1, 49.7 ± 6.9 (P < 0.001). As determined by Cohen's d test, the effect size of an educational program is quite large on the nurse mentors' performance. CONCLUSION: The educational program about mentorship competencies was significantly improve mentorship performance of the studied nurse mentors. The study recommended dissemination and generalization of the new and innovative mentorship program to the different stages of nursing education to foster the continued growth and development of nurse mentors and nurse students. Also, recommended developing a valid mentor assessment instrument consisting of and specific to the Egyptian context to assess the Egyptian mentorship model. TRIAL REGISTRATION NUMBER (TRN): The study protocol was approved by the Research Ethics Committee of the Faculty of Nursing, Port Said University (code number: NUR 13/2/2022) [10].

5.
Radiographics ; 42(4): 968-990, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35622493

RESUMO

Myocardial strain is a measure of myocardial deformation, which is a more sensitive imaging biomarker of myocardial disease than the commonly used ventricular ejection fraction. Although myocardial strain is commonly evaluated by using speckle-tracking echocardiography, cardiovascular MRI (CMR) is increasingly performed for this purpose. The most common CMR technique is feature tracking (FT), which involves postprocessing of routinely acquired cine MR images. Other CMR strain techniques require dedicated sequences, including myocardial tagging, strain-encoded imaging, displacement encoding with stimulated echoes, and tissue phase mapping. The complex systolic motion of the heart can be resolved into longitudinal strain, circumferential strain, radial strain, and torsion. Myocardial strain metrics include strain, strain rate, displacement, velocity, torsion, and torsion rate. Wide variability exists in the reference ranges for strain dependent on the imaging technique, analysis software, operator, patient demographics, and hemodynamic factors. In anticancer therapy cardiotoxicity, CMR myocardial strain can help identify left ventricular dysfunction before the decline of ejection fraction. CMR myocardial strain is also valuable for identifying patients with left ventricle dyssynchrony who will benefit from cardiac resynchronization therapy. CMR myocardial strain is also useful in ischemic heart disease, cardiomyopathies, pulmonary hypertension, and congenital heart disease. The authors review the physics, principles, and clinical applications of CMR strain techniques. Online supplemental material is available for this article. ©RSNA, 2022.


Assuntos
Cardiomiopatias , Imagem Cinética por Ressonância Magnética , Cardiomiopatias/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Imagem Cinética por Ressonância Magnética/métodos , Contração Miocárdica , Física , Reprodutibilidade dos Testes , Função Ventricular Esquerda
6.
J Nurs Adm ; 52(10): 519-524, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36166630

RESUMO

AIM: The aim of this study was to investigate the effect of career plateau as a mediating factor on nurses' job satisfaction and promotability. BACKGROUND: A nurse's career, as well as other professionals, may arrive at a point where further hierarchical development is limited. Nurses may remain longer than expected in the same position within an organization and may be plateaued, resulting in career dissatisfaction, job dissatisfaction, and turnover. METHODS: This is a descriptive correlational study. Two hundred twenty-one nurses were recruited from 1 university hospital in Egypt. Respondents completed the self-administered, printed questionnaires. Measures included career plateau, job satisfaction, and promotability questionnaires. Findings were investigated via descriptive and inferential statistics as well as structured equation modeling to examine the mediating effect of career plateauing on job satisfaction and promotability. RESULTS: The mean scores of job satisfaction, career plateauing, and promotability were 3.09 ± 0.71, 3.75 ± 0.43, and 3.70 ± 0.53, respectively. Data revealed that nurses' career plateauing accounted for 34% and 18% of the variance of their job satisfaction and promotability, respectively. CONCLUSION: Career plateauing is a significant determinant of nurses' job satisfaction and promotability.


Assuntos
Enfermeiras e Enfermeiros , Recursos Humanos de Enfermagem Hospitalar , Atitude do Pessoal de Saúde , Humanos , Satisfação no Emprego , Análise de Mediação , Reorganização de Recursos Humanos , Inquéritos e Questionários
7.
J Viral Hepat ; 28(2): 279-287, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33098209

RESUMO

Oral Direct-acting antivirals (DAAs) are safe, highly effective altering disease burden and prognosis in hepatitis C patients. Sustained virologic response (SVR) is achieved nowadays in more than 90% of the treated patients and related to the improvements in functions of the liver, fibrosis plus survival. Furthermore, portal hypertension is thought to be improved with achievement of virological response, parallel to the improvements in hepatic inflammation and fibrosis. We aimed to assess the recurrence rate of oesophageal varices by long-term follow-up in patients treated with different DAAs regimens who had achieved SVR. We studied 176 Child A cirrhotic HCV patients who achieved SVR after DAAs treatment and had a history of endoscopic oesophageal varices obliteration and were on maximum tolerated propranolol dose. They were subjected to follow-up upper gastrointestinal endoscopy repeated every 6 months for 4 years. Fifty-two patients (29.5%) had recurrence of oesophageal varices observed during the 4-years follow-up upper GIT endoscopy. On multivariate analysis, platelet count was the only significant variable, P-value = .007*. HbA1C, HOMA IR, BMI 1 and BMI 2 showed non-significant differences between the studied groups. By ROC analysis, we identified baseline platelet count of 96 000/µL with 100% sensitivity (95% confidence interval [CI] [91%-100%]) and 74% specificity (95% CI [65%-81%]). Spearman correlation showed a positive correlation between AFP, age, AST, Bilirubin, creatinine, INR. Patients who achieved SVR post DAAs showed a significant decrease in oesophageal varices recurrence post endoscopic obliteration. Baseline platelet count was found to be a strong independent predictor for oesophageal varices recurrence.


Assuntos
Varizes Esofágicas e Gástricas , Hepatite C Crônica , Antivirais/uso terapêutico , Criança , Endoscopia , Varizes Esofágicas e Gástricas/tratamento farmacológico , Varizes Esofágicas e Gástricas/epidemiologia , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Humanos , Cirrose Hepática/tratamento farmacológico , Resposta Viral Sustentada
8.
Radiographics ; 41(4): E126-E137, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34143712

RESUMO

The number of implanted devices such as orthopedic hardware and cardiac implantable devices continues to increase with an increase in the age of the patient population, as well as an increase in the number of indications for specific devices. Many patients with these devices have or will develop clinical conditions that are best depicted at MRI. However, implanted devices containing paramagnetic or ferromagnetic substances can cause significant artifact, which could limit the diagnostic capability of this modality. Performing imaging with MRI when an implant is present may be challenging, and there are numerous techniques the radiologist and technologist can use to help minimize artifacts related to implants. First, knowledge of the presence of an implant before patient arrival is critical to ensure safety of the patient when the device is subjected to a strong magnetic field. Once safety is ensured, the examination should be performed with the MRI system that is expected to provide the best image quality. The selection of the MRI system includes multiple considerations such as the effects of field strength and availability of specific sequences, which can reduce metal artifact. Appropriate patient positioning, attention to MRI parameters (including bandwidth, voxel size, and echo), and appropriate selection of sequences (those with less metal artifact and advanced metal reduction sequences) are critical to improve image quality. Patients with implants can be successfully imaged with MRI with appropriate planning and understanding of how to minimize artifacts. This improves image quality and the diagnostic confidence of the radiologist. ©RSNA, 2021.


Assuntos
Artefatos , Imageamento por Ressonância Magnética , Próteses e Implantes , Humanos , Metais
9.
J Immunoassay Immunochem ; 42(6): 1954947, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34355651

RESUMO

In this study, we aimed to investigate whether serum and urinary levels of kidney injury molecule 1 (KIM-1) are increased in type 2 diabetes mellitus (DM) patients with albuminuria. While the correlation of urinary KIM-1 with renal impairment has been well established, the association with serum KIM-1 has not yet been so well documented. The present pilot study included Egyptian patients with type 2 diabetes (T2D): A total of 84 patients with T2D (age 49-64 years; 20 men) were included in the analysis of the present study. They were divided into two groups according to Alb/Cr ratio: the first group included 32 patients (38.1%) with abnormal Alb/Cr ratio (38.6 mg/g·Cr), and the second group included 52 patients with normal Alb/Cr ratio (17.9 mg/g·Cr). Serum and urinary KIM-1 were measured using enzyme-linked immunoassays. There was a significant difference between both serum and urine KIM-1 and Alb/Cr ratio. Patients with abnormal Alb/Cr ratio had significantly higher serum and urinary KIM-1. These results yielded sensitivity (75.0%) and specificity (96.2%) regarding serum KIM-1 with a cut-off point of 37.5 pg/mL, and sensitivity (93.8%) and specificity (88.5%) regarding urinary KIM1 with a cut-off point of 32.00 ng/g.Cr. Serum KIM-1 and urinary KIM-1 were significantly correlated with eGFR and Alb/Cr ratio. In this pilot study, we found that urinary, serum, and urinary levels of KIM-1 are associated with significant impairments in renal function among diabetic patients. Our results also showed that serum and urine KIM-1 can be used as potential biomarkers for diabetic kidney disease.


Assuntos
Diabetes Mellitus Tipo 2 , Albuminas , Biomarcadores , Creatinina , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Humanos , Rim , Masculino , Pessoa de Meia-Idade , Projetos Piloto
11.
AJR Am J Roentgenol ; 214(3): 546-556, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31967503

RESUMO

OBJECTIVE. A spectrum of pathophysiologic mechanisms can lead to the development of myocardial disorders including ischemia, genetic abnormalities, and systemic disorders. Cardiac MRI identifies different myocardial disorders, provides prognostic information, and directs therapy. In comparison with other imaging modalities, cardiac MRI has the advantage of allowing both functional assessment and tissues characterization in a single examination without the use of ionizing radiation. Newer cardiac MRI techniques including mapping can provide additional information about myocardial disease that may not be detected using conventional techniques. Emerging techniques including MR spectroscopy and finger printing will likely change the way we understand the pathophysiology mechanisms of the wide array of myocardial disorders. CONCLUSION. Imaging of myocardial disorders encompasses a large variety of conditions including both ischemic and nonischemic diseases. Cardiac MRI sequences, such as balanced steady-state free precession and late gadolinium enhancement, play a critical role in establishing diagnosis, determining prognosis, and guiding therapeutic management. Additional sequences-including perfusion imaging, T2*, real-time cine, and T2-weighted sequences-should be performed in specific clinical scenarios. There is emerging evidence for the use of mapping in imaging of myocardial disease. Multiple other new techniques are currently being studied. These novel techniques will likely change the way myocardial disorders are understood and diagnosed in the near future.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Cardiomiopatias/fisiopatologia , Meios de Contraste , Humanos , Interpretação de Imagem Assistida por Computador , Espectroscopia de Ressonância Magnética , Prognóstico
12.
AJR Am J Roentgenol ; 215(2): 374-381, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32374663

RESUMO

OBJECTIVE. Patients with cardiac implantable electronic devices (CIEDs) require cardiac MRI (CMRI) for a variety of reasons. The purpose of this study is to review and evaluate the value and safety of CMRI for patients with in situ CIEDs. CONCLUSION. Late gadolinium enhancement CMRI is the reference standard for assessing myocardial viability in patients with ventricular tachycardia before ablation of arrhythmogenic substrates. The use of late gadolinium enhancement CMRI for patients with CIEDs is safe as long as an imaging protocol is in place and precaution measures are taken.


Assuntos
Técnicas de Imagem Cardíaca , Meios de Contraste , Desfibriladores Implantáveis , Gadolínio , Coração/diagnóstico por imagem , Imageamento por Ressonância Magnética/efeitos adversos , Marca-Passo Artificial , Taquicardia Ventricular/diagnóstico por imagem , Taquicardia Ventricular/cirurgia , Idoso , Técnicas de Imagem Cardíaca/métodos , Feminino , Humanos
13.
AJR Am J Roentgenol ; 213(3): 555-561, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31120781

RESUMO

OBJECTIVE. An important application of late gadolinium enhancement (LGE) cardiac MRI is accurate assessment of myocardial scar before ablation. However, this is often limited in patients with cardiac implantable electronic devices (CIEDs) because of metal device-induced artifacts. The purpose of this study was to determine whether a modified wideband inversion recovery (IR) LGE MRI technique decreases artifact volume to allow the assessment of myocardial scar. SUBJECTS AND METHODS. Fifty patients (17 women and 33 men; mean age ± SD, 61 ± 12 years; mean ejection fraction ± SD, 35.9% ± 13.3%) with CIEDs underwent cardiac MRI using conventional and modified wideband IR LGE techniques before ablation. The volume of device-induced artifact was quantified and stratified by tertiles on mild, moderate, and severe. Ordinal logistic regression analysis assessed the association between artifact volume on conventional and wideband images adjusted for patients' demographics. RESULTS. Conventional LGE MRI resulted in device-induced hyperintense artifacts that obscured ventricular segments in 32 of 50 (64%) cases. Wideband LGE MRI significantly reduced severe artifact volume (p < 0.0001) and completely resolved all mild and most moderate artifacts. Overall, wideband techniques resulted in a 56% reduction in total artifact volume for the cohort (p < 0.0001). The wideband LGE MRI sequence minimized artifacts in the most commonly obscured segments on the conventional LGE MRI sequence, with persistent artifacts in seven, eight, and four of 32 cases at the basal anterior, midventricular anterior, and midventricular anteroseptal segments, respectively. CONCLUSION. The modified wideband IR technique completely resolves mild and moderate device-induced hyperintense artifacts and significantly reduces the volume of severe artifact to allow accurate identification of myocardial scar in patients with CIEDs before ablation.


Assuntos
Artefatos , Cicatriz/diagnóstico por imagem , Desfibriladores Implantáveis , Imageamento por Ressonância Magnética/métodos , Miocárdio/patologia , Marca-Passo Artificial , Meios de Contraste , Feminino , Humanos , Masculino , Metais , Pessoa de Meia-Idade , Estudos Prospectivos
15.
Europace ; 19(5): 812-817, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-27256419

RESUMO

AIMS: Magnetic resonance imaging (MRI) has been reported to be safe in patients with cardiac implantable electronic devices (CIED) provided a specific protocol is followed. The objective of this study was to assess whether this is also true for patients excluded from published protocols. METHODS AND RESULTS: A total of 160 MRIs were obtained in 142 consecutive patients with CIEDs [106 patients had an implantable cardioverter defibrillator (ICD) and 36 had a pacemaker implanted] using an adapted, pre-specified protocol. A cardiac MRI was performed in 95 patients, and a spinal/brain MRI was performed in 47 patients. Forty-six patients (32%) had either abandoned leads (n = 10), and/or were pacemaker dependent with an implanted ICD (n = 19), had recently implanted CIEDs (n = 1), and/or had a CIED device with battery depletion (n = 2), and/or a component of the CIED was recalled or on advisory (n = 32). No major complications occurred. Some device parameters changed slightly, but significantly, right after or at 1-week post-MRI without requiring any reprogramming. In one patient with an ICD on advisory, the pacing rate changed inexplicably during one of his two MRIs from 90 to 50 b.p.m. CONCLUSION: Using a pre-specified protocol, cardiac and non-cardiac MRIs were performed in CIED patients with pacemaker dependency, abandoned leads, or depleted batteries without occurrence of major adverse events. Patients with devices on advisory need to be monitored carefully during MRI, especially if they are pacemaker dependent.


Assuntos
Queimaduras por Corrente Elétrica/etiologia , Contraindicações , Desfibriladores Implantáveis/efeitos adversos , Falha de Equipamento/estatística & dados numéricos , Reação a Corpo Estranho/etiologia , Imageamento por Ressonância Magnética/efeitos adversos , Marca-Passo Artificial/efeitos adversos , Queimaduras por Corrente Elétrica/prevenção & controle , Feminino , Reação a Corpo Estranho/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
J Magn Reson Imaging ; 44(6): 1448-1455, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27240936

RESUMO

PURPOSE: To investigate the effect of the analysis technique on estimating hepatic iron content using MRI. MATERIALS AND METHODS: We evaluated the influences of single-exponential (EXP), bi-exponential (BEXP), and exponential-plus-constant (CEXP) models; and pixel-wise (MAP), average (AVG), and median (MED) signal calculation methods on T2* measurement using numerical simulations, calibrated phantoms, and nine patients scanned on 3 Tesla MRI, based on regression, correlation, and t-test statistical analysis. RESULTS: The T2* measurement error varied from 9 to 51% in the numerical simulations (T2*: 5-20 ms), depending on signal-to-noise ratio (SNR; range: 8-233) with significant (P < 0.05) difference between actual and predicted values. The MAP method performed well (error < 10%) at high SNR (>100), but resulted in severe estimation errors at low SNR (<50). The EXP model resulted in significant measurement differences (P < 0.05) compared with all other methods, irrespective of SNR. In vivo T2* values ranged from 3.1 to 53.6 ms, depending on the amount of iron overload and implemented analysis method. The BEXP (range: 3.7-50 ms) and CEXP (range: 3.8-53.6 ms) models, and the AVG (range: 3.2-38.8 ms) and MED (range: 3.1-38.5 ms) methods provided more accurate measurements than the EXP model (range: 3.1-18.3 ms) and MAP (range: 3.8-53.6 ms) method, respectively (P < 0.05). The BEXP and CEXP models provided very similar measurements (P > 0.87). Similarly, the AVG and MED methods provided very similar results (P > 0.97), with slightly better performance of the AVG method. CONCLUSION: Different analysis techniques show different performances based on the fitting model and signal calculation method. Based on this study, the CEXP model and AVG method are recommended due to simpler implementation and less influence by the selected analysis region. J. Magn. Reson. Imaging 2016;44:1448-1455.


Assuntos
Anemia Falciforme/diagnóstico por imagem , Anemia Falciforme/metabolismo , Interpretação de Imagem Assistida por Computador/métodos , Ferro/metabolismo , Fígado/diagnóstico por imagem , Fígado/metabolismo , Imageamento por Ressonância Magnética/métodos , Adulto , Algoritmos , Feminino , Humanos , Masculino , Imagem Molecular/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
J Magn Reson Imaging ; 44(2): 463-70, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26788935

RESUMO

PURPOSE: To assess the effects of cerebrospinal fluid (CSF) bidirectional motion in Chiari malformation type I (CMI), we monitored CSF velocity amplitudes on phase contrast MRI (PC-MRI) in patients before and after surgery; and in healthy volunteers. MATERIALS AND METHODS: 10 pediatric volunteers and 10 CMI patients participated in this study. CMI patients underwent PC-MRI scans before and approximately 14 months following surgery. Two parameters-amplitude of mean velocity (AMV) and amplitude of peak velocity (APV) of CSF-were derived from the data. Measurements were made at the mid-portion of the cerebral aqueduct, and anterior and posterior compartments of the spinal canal at the craniovertebral junction (CVJ). RESULTS: AMV and APV within the cerebral aqueduct were greater in preoperative assessments of the CMI patients compared to normal volunteers. Statistical significance was noted when comparing aqueductal AMV between the preoperative values and normal controls (P = 0.03), and before and after surgery in the CMI patients (P = 0.02). Lower values of AMV (P = 0.02) were noted in the anterior CVJ compartment in the patients before and after surgery when compared to the normal volunteers. There were no significant correlations (P = 0.06) noted for the APV at the CVJ between the normal control and patients, before or after surgery. CONCLUSION: In pediatric CMI patients, AMV for CSF within the cerebral aqueduct and anterior CVJ subarachnoid space are significantly elevated preoperatively and normalize following surgery. Given the biphasic CSF motion, measuring amplitude accounts for cranial and caudal flow. It may offer an alternative parameter to assess postsurgical outcome. J. Magn. Reson. Imaging 2016;44:463-470.


Assuntos
Malformação de Arnold-Chiari/diagnóstico por imagem , Malformação de Arnold-Chiari/cirurgia , Aqueduto do Mesencéfalo/diagnóstico por imagem , Líquido Cefalorraquidiano/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Malformação de Arnold-Chiari/líquido cefalorraquidiano , Aqueduto do Mesencéfalo/patologia , Líquido Cefalorraquidiano/citologia , Descompressão Cirúrgica , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Reologia/métodos , Sensibilidade e Especificidade , Resultado do Tratamento
19.
J Nucl Cardiol ; 23(5): 960-969, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27146882

RESUMO

BACKGROUND: In type I diabetes (T1DM), alterations in LV function may occur due to changes in innervation, metabolism, and efficiency. OBJECTIVES: We evaluated the association between sympathetic nerve function, oxidative metabolism, resting blood flow, LV efficiency and function in healthy diabetics, and assessed gender differences. METHODS: Cross-sectional study of 45 subjects with T1DM, 60% females, age 34 ± 13 years, and 10 age-matched controls. Positron emission tomography (PET) imaging with [(11)C]acetate and [(11)C]meta-hydroxyephedrine was performed, in addition to cardiac magnetic resonance imaging. RESULTS: There were no significant differences in LV function, innervation, or oxidative metabolism between T1DM and controls. Cardiac oxidative metabolism was positively associated with higher levels of sympathetic activation, particularly in women. Diabetic women had significantly lower efficiency compared with diabetic men. Resting flow was significantly higher in diabetic women compared with diabetic men, and tended to be higher in female controls as well. CONCLUSIONS: Measures of myocardial function, metabolism, blood flow, and sympathetic activation were preserved in young, otherwise healthy, T1DM patients. However, T1DM women presented with greater myocardial oxidative metabolism requirements than men. Ongoing studies are evaluating changes over time.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Cardiomiopatias Diabéticas/fisiopatologia , Efedrina/farmacocinética , Ventrículos do Coração/fisiopatologia , Volume Sistólico , Sistema Nervoso Simpático/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Adulto , Velocidade do Fluxo Sanguíneo , Circulação Coronária , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/diagnóstico por imagem , Cardiomiopatias Diabéticas/diagnóstico por imagem , Cardiomiopatias Diabéticas/etiologia , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Caracteres Sexuais , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia
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