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2.
BMC Med Res Methodol ; 24(1): 78, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38539117

RESUMO

BACKGROUND: The screening process for systematic reviews and meta-analyses in medical research is a labor-intensive and time-consuming task. While machine learning and deep learning have been applied to facilitate this process, these methods often require training data and user annotation. This study aims to assess the efficacy of ChatGPT, a large language model based on the Generative Pretrained Transformers (GPT) architecture, in automating the screening process for systematic reviews in radiology without the need for training data. METHODS: A prospective simulation study was conducted between May 2nd and 24th, 2023, comparing ChatGPT's performance in screening abstracts against that of general physicians (GPs). A total of 1198 abstracts across three subfields of radiology were evaluated. Metrics such as sensitivity, specificity, positive and negative predictive values (PPV and NPV), workload saving, and others were employed. Statistical analyses included the Kappa coefficient for inter-rater agreement, ROC curve plotting, AUC calculation, and bootstrapping for p-values and confidence intervals. RESULTS: ChatGPT completed the screening process within an hour, while GPs took an average of 7-10 days. The AI model achieved a sensitivity of 95% and an NPV of 99%, slightly outperforming the GPs' sensitive consensus (i.e., including records if at least one person includes them). It also exhibited remarkably low false negative counts and high workload savings, ranging from 40 to 83%. However, ChatGPT had lower specificity and PPV compared to human raters. The average Kappa agreement between ChatGPT and other raters was 0.27. CONCLUSIONS: ChatGPT shows promise in automating the article screening phase of systematic reviews, achieving high sensitivity and workload savings. While not entirely replacing human expertise, it could serve as an efficient first-line screening tool, particularly in reducing the burden on human resources. Further studies are needed to fine-tune its capabilities and validate its utility across different medical subfields.


Assuntos
Benchmarking , Pesquisa Biomédica , Humanos , Revisões Sistemáticas como Assunto , Simulação por Computador , Consenso
3.
Cardiovasc Intervent Radiol ; 47(4): 416-431, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38528173

RESUMO

PURPOSE: This study aims to provide a comprehensive review of the clinical benefits, complications, and safety profile associated with preoperative embolization in Glomus jugulare tumors (GJTs). MATERIALS AND METHODS: A comprehensive search in PubMed, Embase, and Web of Science was conducted for English articles published up to March 2023, focusing on GJTs and preoperative embolization. Included studies involved patients over 18 with GJTs. We excluded studies that explored embolization methods other than the standard endovascular approach, as well as studies involving paragangliomas that did not provide specific data related to GJTs. Key variables such as hemorrhage volume and surgical time, as well as clinical outcomes, were analyzed. Data were analyzed using a random-effects model meta-analysis, assessing heterogeneity with the I2 statistic. RESULTS: This review encompasses 19 studies with a total of 328 patients. The studies incorporated into our meta-analysis display considerable differences and inconsistencies in their data. The findings of the meta-analysis show a mean hemorrhage volume of 636 ml (95% confidence interval (CI) 473-799) following preoperative embolization, and a mean surgical duration of 487 min (95% CI 350-624). The study also notes potential complications: facial nerve deficits occurred in 20% of cases (95% CI 11-32%), and vagal nerve deficits in 22% (95% CI 13-31%). CONCLUSION: This study suggests that preoperative embolization could decrease surgery duration and blood loss, but emphasizes the importance of evaluating risks like nerve damage. However, the generalizability of these findings is restricted due to the diversity of available data.


Assuntos
Embolização Terapêutica , Tumor do Glomo Jugular , Humanos , Tumor do Glomo Jugular/terapia , Tumor do Glomo Jugular/irrigação sanguínea , Tumor do Glomo Jugular/patologia , Embolização Terapêutica/métodos , Hemorragia , Resultado do Tratamento , Estudos Retrospectivos
4.
Int J Vasc Med ; 2024: 6829868, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38356738

RESUMO

Introduction: This study investigates the long-term effectiveness and safety of endovenous laser treatment (EVLT) for chronic venous insufficiency (CVI), a condition commonly caused by dysfunctional valves in the venous circulation system. Materials and Methods: In this retrospective cohort study, patients underwent EVLT and were followed up for successive short intervals and one last time after a median duration of 9-year postprocedural. Pre- and postprocedure duplex ultrasound was used to assess changes in the great saphenous vein (GSV) diameter, reflux, and saphenofemoral junction incompetence. Quality of life was evaluated using the SF-36 and Aberdeen Varicose Vein Questionnaire (AVVQ). Results: Sixty-eight patients with a mean age of 52.4 ± 12.4 years were enrolled in the study. The mean follow-up time was 8.9 ± 2.1 years, ranging from 5 to 12 years. The mean GSV diameter significantly decreased in all patients (whole group) across proximal (from 5.8 ± 2.3 mm to 4.2 ± 2.1 mm), middle (from 4.7 ± 1.6 mm to 2.8 ± 2.2 mm), and distal (from 4.5 ± 2.3 mm to 2.2 ± 2.2 mm) segments, with P < 0.001. A disease recurrence rate of 33.8% was noted, predominantly in male patients and those with larger middle GSV diameters (OR = 5.2 (95%CI = 1.3-20.4) and OR = 1.5 (95%CI = 1-2.1), respectively). The average follow-up time for patients without recurrence was 8.8 ± 2.1 years. Almost half of the patients without recurrence were followed up for 10 years or more (49%). Conclusion: The efficacy of EVLT in managing varicose veins is demonstrated by its relatively low recurrence rate over a 10-year follow-up period, highlighting EVLT as a viable long-term treatment strategy.

5.
Indian J Radiol Imaging ; 33(4): 514-521, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37811185

RESUMO

Background High-grade gliomas (HGGs) are the most prevalent primary malignancy of the central nervous system. The tumor results in vasogenic and infiltrative edema . Exact anatomical differentiation of these edemas is so important for surgical planning. Multimodal imaging could be used to differentiate the edema type. Purpose The aim of this study was to investigate the role of multimodal imaging in the differentiation of vasogenic edema from infiltrative edema in patients with HGG (grade III and grade IV). Data Sources A search on PubMed, EMBASE, Scopus, and ISI Web of Science Core Collection up to June 2022 using terms related to (a) multimodal imaging AND (b) HGG AND (c) edema. (PROSPERO registration number: CRD42022336131) Study Selection Two reviewers screened the articles and independently extracted the data. We included original articles assessing the role of multimodal imaging in differentiating vasogenic from infiltrative edema in patients with HGG. Six high-quality articles remained for the narrative synthesis. Data Synthesis Dynamic susceptibility contrast imaging showed that relative cerebral blood volume and relative cerebral blood flow were higher in the infiltrative edema component than in the vasogenic edema component. Diffusion tensor imaging revealed a dispute on fractional anisotropy. The apparent diffusion coefficient was comparable between the two edematous components. Magnetic resonance spectroscopy exhibited an increment in choline/creatinine ratio and choline/N-acetyl aspartate ratio in the infiltrative edema component. Limitations Strict study selection, low sample size of relevant published studies, and heterogeneity in endpoint variables were the major drawbacks. Conclusions Multimodal imaging, including dynamic susceptibility contrast and magnetic resonance spectroscopy, might help differentiate between vasogenic and infiltrative edema.

6.
J Vasc Interv Radiol ; 34(7): 1184-1191.e2, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36972845

RESUMO

PURPOSE: To systematically review published studies on the pregnancy rate and outcomes after uterine artery embolization (UAE) for uterine arteriovenous malformations (UAVMs). MATERIALS AND METHODS: International medical databases were searched for all English-language studies published between 2000 and 2022 on patients with UAVMs who had undergone embolization and had a subsequent pregnancy. Data on the pregnancy rate, pregnancy complications, and physiologic status of newborns were extracted from the articles. Ten case series were included in the meta-analysis, and 18 case reports on pregnancy following UAE were reviewed. RESULTS: In the case series, 44 pregnancies were reported in 189 patients. The pooled estimate of pregnancy rate was 23.3% (95% confidence interval [CI], 17.3%-29.3%). The pregnancy rate was higher in studies of women with a mean age of ≤30 years (50.6% vs 22.2%; P < .05). The pooled estimate of live birth rate was 88.6% (95% CI, 78.6%-98.7%). CONCLUSIONS: All published series report preservation of fertility and successful pregnancies after embolization of UAVMs. The live birth rate in these series does not differ substantially from that of the general population.


Assuntos
Malformações Arteriovenosas , Embolização da Artéria Uterina , Gravidez , Humanos , Recém-Nascido , Feminino , Adulto , Embolização da Artéria Uterina/efeitos adversos , Taxa de Gravidez , Fertilidade , Malformações Arteriovenosas/diagnóstico por imagem , Malformações Arteriovenosas/terapia
7.
Br J Neurosurg ; 37(5): 1031-1039, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33263433

RESUMO

OBJECTIVE: To determine the border of glial tumors by diffusion weighted imaging (DWI), apparent diffusion co-efficient (ADC), magnetic resonance spectroscopy (MRS) and perfusion brain MRI. PATIENTS AND METHODS: Ten patients with brain gliomas were enrolled [mean age: 35.3 ± 13.2, range: 20-62]. Conventional MRI was performed for all patients. Besides, tumor mapping based on Choline (Cho)/Creatine (Cr) color map in MRS, perfusion and diffusion color maps, were gathered. Different tumoral and peritumoral regions [normal tissue, reactive edema, infiltrative edema, and tumor core] were defined. MRI criteria were evaluated in areas targeted for biopsy and histopathologic evaluation was determined. RESULTS: Tumor cell positive samples [one necrosis, 26 infiltrative and nine tumor cores] composed 36 (75%) of the 48 samples. Seven (19.4%) of the positive samples were interpreted as not tumor on MRI. Five were identified as reactive edema and two as normal tissue] [kappa: .67, p-value < .001]. Mean of ADC, median of N-acetylaspartate (NAA) and NAA/Cho were statistically different between positive and negative samples (p = .02 and p < .001, respectively). Mean ADC and median Cho/NAA were statistically different in missed tumor containing tissue presented as reactive edema compared to normal and correctly diagnosed reactive edema samples together (p-values < .05). CONCLUSIONS: Multimodal MRI could define infiltrated borders of brain gliomas.


Assuntos
Neoplasias Encefálicas , Glioma , Humanos , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Glioma/complicações , Glioma/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Edema/diagnóstico por imagem , Edema/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia
8.
J Otol ; 17(3): 123-129, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35847569

RESUMO

Purpose: To investigate the correlation between vestibular hydrops (VH), cochlearhydrops (CH), vestibular aqueduct non-visibility (VANV), and visually increased perilymphatic enhancement (VIPE) with the findings of pure-tone audiometry (PTA) in Meniere's disease (MD) patients. Methods: In this cross-sectional study, 53 ears belonging to 48 patients were divided into two groups and evaluated. In group "MD patients," there were 24 ears of 19 patients diagnosed with the definite MD (14 patients with unilateral and 5 patients withbilateral involvements). The "control group" consisted of 29 non-symptomatic ears belonging to patients diagnosed with unilateral sudden sensory-neural hearing loss or unilateral schwannoma. All the patients underwent 2 sessions of temporal bone MRI using the same 3T system: an unenhanced axial T1, T2, and 3D-FLAIR MRI, an intravenous gadolinium-enhanced axial T1 fat-sat, and 4 h after the injection, an axial 3D-T2 cube and 3D-FLAIR session. VH, CH, VANV, and VIPE were assessed. Subsequently, the correlation between EH indices and PTA findings (in three frequency domains of low, middle, and high) were evaluated, and the predictive value of MRI was calculated. Results: VH was significantly correlated with the hearing threshold in the low, middle, and high-frequency domains. CH was also correlated with the hearing threshold in the low and middle domains. Contrarily, VIPE was not associated with hearing thresholds, and VANV was only correlated with the hearing threshold in low frequencies. Conclusion: The grade of VH, CH, and VANV were significantly correlated with the hearing thresholds in PTA.

10.
J Clin Ultrasound ; 50(9): 1288-1296, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35635295

RESUMO

BACKGROUND: This study aimed to investigate the additional advantages of magnetic resonance imaging (MRI), particularly diffusion-weighted imaging (DWI) over fetal ultrasound in the detection of acute ischemic cerebral injuries in complicated monochorionic (MC) pregnancies that underwent selective reduction by radiofrequency ablation (RFA). METHODS: This prospective cohort study was conducted on 40 women with complicated MC pregnancies who were treated by RFA. Fetal brain imaging by DWI and conventional MRI was performed either in the early (within 10 days after RFA) or late phase (after 3-6 weeks) in the surviving fetuses to detect both acute and chronic ischemic injuries. The presence of anemia after RFA was also evaluated by Doppler ultrasound. RESULTS: Overall, 13 of the total 43 fetuses (30.23%) demonstrated MRI abnormalities with normal brain ultrasound results including germinal matrix hemorrhage (GMH), extensive cerebral ischemia, and mild ventriculomegaly. Although seven fetuses with GMH eventually survived, fetuses that demonstrated ischemic lesions and ventriculomegaly on MRI died in the uterus. CONCLUSION: The absence of abnormal cerebral lesions or anemia on ultrasound and Doppler exams does not necessarily rule out fetal brain ischemia. Performing early MRI, particularly DWI seems to be a reasonable option for detection of early intracranial ischemic changes and better management of complicated multiple pregnancies which were treated by RFA.


Assuntos
Lesões Encefálicas , Isquemia Encefálica , Ablação por Cateter , Doenças Fetais , Hidrocefalia , Gravidez , Feminino , Humanos , Redução de Gravidez Multifetal/métodos , Estudos Prospectivos , Hemorragia Cerebral , Lesões Encefálicas/diagnóstico por imagem , Lesões Encefálicas/cirurgia , Estudos Retrospectivos
11.
Cardiovasc Intervent Radiol ; 45(7): 983-991, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35296933

RESUMO

PURPOSE: To describe the clinical and fertility outcomes after uterine artery embolization (UAE) for symptomatic uterine arteriovenous malformations (AVMs). MATERIALS AND METHODS: This single-center retrospective study included 33 patients with uterine AVMs who underwent UAE at our institution between May 2013 and May 2021. The inclusion criteria were diagnostic features of uterine AVM as detection of the nidus and early venous drainage on angiography. The exclusion criteria were high levels of beta-human chorionic gonadotropin indicative of gestational trophoblastic neoplasia. Polyvinyl alcohol (PVA) with a diameter of 500-700 µm (with or without Gelfoam/Glue) was used in 32 procedures and, Glue (with lipiodol) was used in one. The patients were followed up for 31 months (range, 6-90 months). Angiograms, medical records, and phone interviews were used to describe the technical and clinical success, complications, and pregnancy outcomes. RESULTS: Thirty-three patients with a mean age of 31.2 ± 5.4 years (range, 21-42 years) were included in this case series. Technical success was reported in all patients (100%). Bleeding control was also achieved in 32 (96%) patients. Pelvic and puncture site pain and groin hematoma were reported as minor complications (grade 1 according to CIRSE classification). Six pregnancies (33%) occurred after uterine artery embolization. Four women had full-term pregnancies without complications and delivered healthy newborns. Another two women were in the second trimester of pregnancy with a favorable fetal condition. No post-embolization miscarriage was reported. CONCLUSION: The UAE is safe and effective in controlling vaginal bleeding caused by uterine AVMs, allowing successful future pregnancies.


Assuntos
Malformações Arteriovenosas , Embolização da Artéria Uterina , Adulto , Malformações Arteriovenosas/diagnóstico por imagem , Malformações Arteriovenosas/terapia , Feminino , Fertilidade , Humanos , Recém-Nascido , Gravidez , Estudos Retrospectivos , Resultado do Tratamento , Artéria Uterina/diagnóstico por imagem , Embolização da Artéria Uterina/métodos , Hemorragia Uterina/terapia
12.
NPJ Digit Med ; 4(1): 11, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33514852

RESUMO

The Coronavirus disease 2019 (COVID-19) presents open questions in how we clinically diagnose and assess disease course. Recently, chest computed tomography (CT) has shown utility for COVID-19 diagnosis. In this study, we developed Deep COVID DeteCT (DCD), a deep learning convolutional neural network (CNN) that uses the entire chest CT volume to automatically predict COVID-19 (COVID+) from non-COVID-19 (COVID-) pneumonia and normal controls. We discuss training strategies and differences in performance across 13 international institutions and 8 countries. The inclusion of non-China sites in training significantly improved classification performance with area under the curve (AUCs) and accuracies above 0.8 on most test sites. Furthermore, using available follow-up scans, we investigate methods to track patient disease course and predict prognosis.

13.
Cardiovasc Intervent Radiol ; 43(8): 1122-1133, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32458009

RESUMO

Uterine artery embolization (UAE) has been introduced for uterine fibroid treatment for two decades. Most of the patients are in reproductive age and many want future pregnancy. In this study, we will assess fertility, pregnancy and its outcomes in patients who have undergone UAE. In this systematic review, a systematic search was performed on important databases including PubMed and Medline, Web of Knowledge, Google Scholar, EMBASE and Scopus. Studies reported enough data about pregnancy after UAE were considered to be enrolled in the review. We assessed obstetric indices (pregnancy and delivery rates, pregnancy losses, complications and fetal outcomes). Study evaluation was done based on STROBE checklist by two reviewers. Totally, 24 original papers were included. Data were analyzed by Stata and MedCalc softwares. Among women wishing fertility, totally 40.5% experienced at least one pregnancy after UAE (95% confidence interval [CI]: 33.3%-48.2%). Pooled estimate of pregnancy loss rate was 33.5% (95% CI: 26.3-41%). Most pregnancy losses were due to spontaneous abortion (81.3% of all losses (95% CI = 76%-86.1%)). Rate of obstetrical complications was 25.4% (95% CI = 13-40.2%) among all finished pregnancies. Pooled estimate of preterm labor was 12.8% (95% CI = 8.7%-17.5%), and pooled estimate of low birth weight (LBW) was 10% (95% CI = 6.2-14.6%). Considering the findings of the study, a safe pregnancy after UAE is obviously possible resulting to a healthy and normal baby delivery. In addition, pooled obstetrical complication rates, pregnancy losses, preterm labor and LBW seem to be mostly similar to the general population. Registration: The study was registered in International Prospective Register of Systematic Reviews (PROSPERO) on Nov 3, 2017, and was confirmed with a registration code of CRD42017076074.


Assuntos
Leiomioma/terapia , Resultado da Gravidez , Embolização da Artéria Uterina/métodos , Neoplasias Uterinas/terapia , Adulto , Feminino , Humanos , Gravidez
14.
J Clin Imaging Sci ; 8: 2, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29441225

RESUMO

BACKGROUND: Brain tumor is one of the most common tumors. A successful treatment might be achieved with an early identification. Pathological investigation as the gold standard method for tumor identification has some limitations. Noninvasive assessment of tumor specifications may be possible using perfusion-weighted magnetic resonance imaging (MRI). Cerebral blood volume (CBV) and cerebral blood flow (CBF) could be calculated based on dynamic contrast-enhanced MRI (DCE-MRI) in addition to dynamic susceptibility contrast MRI (DSC-MRI) modality. Each category of the cerebral hemodynamic and permeability indices revealed the specific tumor characteristics and their collection could help for better identification of the tumor. Some mathematical methods were developed to determine both cerebral hemodynamic and permeability indices based on a single-dose DCE perfusion MRI. There are only a few studies available on the comparison of DSC- and DCE-derived cerebral hemodynamic indices such as CBF and CBV. AIM: The objective of the study was to validate first-pass perfusion parameters derived from T1-based DCE method in comparison to the routine T2*-based DSC protocol. MATERIALS AND METHODS: Twenty-nine patients with brain tumor underwent DCE- and DSC-MRIs to evaluate the agreement between DSC- and DCE-derived cerebral hemodynamic parameters. Agreement between DSC- and DCE-derived cerebral hemodynamic indices was determined using the statistical method described by Bland and Altman. The reliability between DSC- and DCE-derived cerebral hemodynamic indices was measured using the intraclass correlation analysis. RESULTS: The achieved magnitudes for DCE-derived CBV (gray matter [GM]: 5.01 ± 1.40 mL/100 g vs. white matter [WM]: 1.84 ± 0.74 mL/100 g) and DCE-derived CBF (GM: 60.53 ± 12.70 mL/100 g/min vs. WM: 32.00 ± 6.00 mL/100 g/min) were in good agreement with other studies. The intraclass correlation coefficients showed that the cerebral hemodynamic indices could accurately be estimated based on the DCE-MRI using a single-compartment model (>0.87), and DCE-derived cerebral hemodynamic indices are significantly similar to the magnitudes achieved based on the DSC-MRI (P < 0.001). Furthermore, an acceptable agreement was observed between DSC- and DCE-derived cerebral hemodynamic indices. CONCLUSION: Based on the measurement of the cerebral hemodynamic and blood-brain barrier permeability using DCE-MRI, a more comprehensive collection of the physiological parameters cloud be achieved for tumor evaluations.

15.
J Magn Reson Imaging ; 48(4): 938-950, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29412496

RESUMO

BACKGROUND: Targeted localized biopsies and treatments for diffuse gliomas rely on accurate identification of tissue subregions, for which current MRI techniques lack specificity. PURPOSE: To explore the complementary and competitive roles of a variety of conventional and quantitative MRI methods for distinguishing subregions of brain gliomas. STUDY TYPE: Prospective. POPULATION: Fifty-one tissue specimens were collected using image-guided localized biopsy surgery from 10 patients with newly diagnosed gliomas. FIELD STRENGTH/SEQUENCE: Conventional and quantitative MR images consisting of pre- and postcontrast T1 w, T2 w, T2 -FLAIR, T2 -relaxometry, DWI, DTI, IVIM, and DSC-MRI were acquired preoperatively at 3T. ASSESSMENT: Biopsy specimens were histopathologically attributed to glioma tissue subregion categories of active tumor (AT), infiltrative edema (IE), and normal tissue (NT) subregions. For each tissue sample, a feature vector comprising 15 MRI-based parameters was derived from preoperative images and assessed by a machine learning algorithm to determine the best multiparametric feature combination for characterizing the tissue subregions. STATISTICAL TESTS: For discrimination of AT, IE, and NT subregions, a one-way analysis of variance (ANOVA) test and for pairwise tissue subregion differentiation, Tukey honest significant difference, and Games-Howell tests were applied (P < 0.05). Cross-validated feature selection and classification methods were implemented for identification of accurate multiparametric MRI parameter combination. RESULTS: After exclusion of 17 tissue specimens, 34 samples (AT = 6, IE = 20, and NT = 8) were considered for analysis. Highest accuracies and statistically significant differences for discrimination of IE from NT and AT from NT were observed for diffusion-based parameters (AUCs >90%), and the perfusion-derived parameter as the most accurate feature in distinguishing IE from AT. A combination of "CBV, MD, T2 _ISO, FLAIR" parameters showed high diagnostic performance for identification of the three subregions (AUC ∼90%). DATA CONCLUSION: Integration of a few quantitative along with conventional MRI parameters may provide a potential multiparametric imaging biomarker for predicting the histopathologically proven glioma tissue subregions. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;48:938-950.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Imageamento por Ressonância Magnética , Adulto , Idoso , Algoritmos , Biópsia , Meios de Contraste , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
16.
Iran J Radiol ; 13(1): e18217, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27110332

RESUMO

BACKGROUND: Hemodynamics is thought to play an important role in the mechanisms responsible for initiation, growth, and rupture of intracranial aneurysms. Computational fluid dynamic (CFD) analysis is used to assess intra-aneurysmal hemodynamics. OBJECTIVES: This study aimed to investigate the effects of variations in heart rate and internal carotid artery (ICA) flow rate on intra-aneurysmal hemodynamics, in an ICA aneurysm, by using computational fluid dynamics. PATIENTS AND METHODS: Computed tomography angiography (CTA) was performed in a 55 years old female case, with a saccular ICA aneurysm, to create a patient-specific geometrical anatomic model of the aneurysm. The intra-aneurysmal hemodynamic environments for three states with different flow and heart rates were analyzed using patient-specific image-based CFD modeling. RESULTS: Results showed significant changes for the three simulated states. For a proportion of the states examined, results were counterintuitive. Systolic and time-averaged wall shear stress and pressure on the aneurysm wall showed a proportional evolution with the mainstream flow rate. CONCLUSION: Results reinforced the pivotal role of vascular geometry, with respect to hemodynamics, together with the importance of performing patient-specific CFD analyses, through which the effect of different blood flow conditions on the aneurysm hemodynamics could be evaluated.

17.
Iran J Radiol ; 12(3): e10986, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26535107

RESUMO

BACKGROUND: Rupture of the intracranial aneurysms is associated with a high risk of bleeding and a high incidence of mortality if left untreated. OBJECTIVES: The aim of this study is to report our experience in managing intracranial aneurysms using coil embolization and to report the 6-month follow-up outcome of the patients. PATIENTS AND METHODS: From January 2010 to December 2012, a series of 90 nonrandomized consecutive patients (mean age: 44.6 ± 14.9 years) with intracranial aneurysms underwent endovascular coil embolization in our center. We excluded patients with dissecting, blood blister-like, or false aneurysms. All patients were evaluated by four-vessel angiography to determine the shape, size, number and location of the aneurysms. We recommended a six-month follow-up control angiography. However, only 38 of them participated in this follow-up imaging. The data were analyzed by chi-square, fisher exact and t-tests and alpha was considered lower than 5%. RESULTS: Immediately after the procedure, the total occlusion was seen in 76 (86.4%), subtotal occlusion in six (6.8%), and partial occlusion in six patients (6.8%). There was no significant relationship between the aneurysm size, aneurysm neck size, and location of the aneurysm with total or subtotal occlusions. Eleven patients (12.5%) experienced some complication during the procedure including two tears, three focal neurological signs, three vision disturbances, and three bleedings in the aneurysm. Major complications were significantly higher in the posterior aneurysm compared to the anterior ones (55.6% versus 44.4% of the major complications; P value = 0.015). Among patients who underwent control angiography, 34 patients (89.4%) had no change, two (5.3%) had new growth and two (5.3%) had widening of the neck after 6 months follow-up. Although aneurysms that remained unchanged after six months follow-up angiography had total occlusion after the procedure, it was 50% for aneurysms that had any changes in 6 months follow-up angiography (P value = 0.01). CONCLUSION: Coil embolization showed successful outcomes in the treatment of intracranial aneurysms with a low complication rate.

18.
Cardiovasc Intervent Radiol ; 38(4): 977-84, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25944147

RESUMO

BACKGROUND: Renal nerves are a recent target in the treatment of hypertension. Renal sympathetic denervation (RSD) is currently performed using catheter-based radiofrequency ablation (RFA) and because this method has limitations, percutaneous magnetic resonance (MR)-guided periarterial ethanol injection is a suggested alternative. However, few studies have been conducted on the effectiveness of percutaneous ethanol injection for RSD. AIM: To evaluate the feasibility, efficacy, and complications of computed tomography (CT)-guided periarterial ethanol injection. METHODS: Ethanol (10 ml, 99.6%) was injected around the right renal artery in six sheep under CT guidance with the left kidney serving as a control. Before and after the intervention, the sheep underwent MR imaging studies and the serum creatinine level was measured. One month after the intervention, the sheep were euthanized and norepinephrine (NE) concentration in the renal parenchyma was measured to evaluate the efficacy of the procedure. The treated tissues were also examined histopathologically to evaluate vascular, parenchymal, and neural injury. RESULTS: The right kidney parenchymal NE concentration decreased significantly compared with the left kidney after intervention (average reduction: 40%, P = 0.0016). Histologic examination revealed apparent denervation with no other vascular or parenchymal injuries observed in the histological and imaging studies. CONCLUSION: Effective and feasible RSD was achieved using CT-guided periarterial ethanol injection. This technique may be a potential alternative to catheter-based RFA in the treatment of hypertension.


Assuntos
Etanol/administração & dosagem , Rim/inervação , Radiografia Intervencionista , Artéria Renal/diagnóstico por imagem , Simpatectomia/métodos , Tomografia Computadorizada por Raios X , Animais , Estudos de Viabilidade , Modelos Animais , Ovinos
19.
Iran J Neurol ; 14(1): 22-8, 2015 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-25874053

RESUMO

BACKGROUND: Management of intracranial aneurysms has made debates about the best treatment modality in recent years. The aim of this study was to compare the interventional outcomes between two groups of patients, one treated with endovascular coiling and the other treated with surgical clipping. METHODS: This prospective study included 48 patients with intracranial aneurysms who underwent endovascular coiling (27 patients) or surgical clipping (21 patients) from July 2011 to August 2013. A neurologist examined patients in admission and followed them by phone call 1-year after intervention. RESULTS: Mean modified Rankin Scale (MRS) score at the time of admission in endovascular group was 2.86 ± 0.974 whereas it was 3.81 ± 1.078 in surgical clipping group (P = 0.0040). Focal neurologic signs were higher in clipping during procedures (P = 0.0310). Of 37 patients who followed up for a year, 19 were in endovascular group and 18 in surgical clipping group. At 1 year follow-up, MRS improvement was statistically significant in coiling group (P = 0.0090), but not in clipping group (P = 0.8750). Mean difference of MRS score at the time of admission and at one year later, was 0.947 ± 1.224 in endovascular group and 0.111 ± 2.083 in surgical group (P = 0.3000). CONCLUSION: There was no statistically significant difference at 1 year outcome between two groups. We recommend further interventional studies with larger sample sizes for better evaluation of the modalities.

20.
Neuroimage Clin ; 7: 306-14, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25610795

RESUMO

Neuromyelitis optica (NMO) exhibits substantial similarities to multiple sclerosis (MS) in clinical manifestations and imaging results and has long been considered a variant of MS. With the advent of a specific biomarker in NMO, known as anti-aquaporin 4, this assumption has changed; however, the differential diagnosis remains challenging and it is still not clear whether a combination of neuroimaging and clinical data could be used to aid clinical decision-making. Computer-aided diagnosis is a rapidly evolving process that holds great promise to facilitate objective differential diagnoses of disorders that show similar presentations. In this study, we aimed to use a powerful method for multi-modal data fusion, known as a multi-kernel learning and performed automatic diagnosis of subjects. We included 30 patients with NMO, 25 patients with MS and 35 healthy volunteers and performed multi-modal imaging with T1-weighted high resolution scans, diffusion tensor imaging (DTI) and resting-state functional MRI (fMRI). In addition, subjects underwent clinical examinations and cognitive assessments. We included 18 a priori predictors from neuroimaging, clinical and cognitive measures in the initial model. We used 10-fold cross-validation to learn the importance of each modality, train and finally test the model performance. The mean accuracy in differentiating between MS and NMO was 88%, where visible white matter lesion load, normal appearing white matter (DTI) and functional connectivity had the most important contributions to the final classification. In a multi-class classification problem we distinguished between all of 3 groups (MS, NMO and healthy controls) with an average accuracy of 84%. In this classification, visible white matter lesion load, functional connectivity, and cognitive scores were the 3 most important modalities. Our work provides preliminary evidence that computational tools can be used to help make an objective differential diagnosis of NMO and MS.


Assuntos
Algoritmos , Diagnóstico por Computador/métodos , Esclerose Múltipla/diagnóstico , Neuromielite Óptica/diagnóstico , Adulto , Diagnóstico Diferencial , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Masculino
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