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1.
Kidney Int ; 101(4): 804-813, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35031327

RESUMO

Kidney cortical interstitial fibrosis is highly predictive of kidney prognosis and is currently assessed by evaluation of a biopsy. Diffusion-weighted magnetic resonance imaging is a promising non-invasive tool to evaluate kidney fibrosis. We recently adapted diffusion-weighted imaging sequence for discrimination between the kidney cortex and medulla and found that the cortico-medullary difference in apparent diffusion coefficient (ΔADC) correlated with histological interstitial fibrosis. Here, we assessed whether ΔADC as measured with diffusion-weighted magnetic resonance imaging is predictive of kidney function decline and dialysis initiation in chronic kidney disease (CKD) and patients with a kidney allograft in a prospective study encompassing 197 patients. We measured ΔADC in 43 patients with CKD (estimated GFR (eGFR) 55ml/min/1.73m2) and 154 patients with a kidney allograft (eGFR 53ml/min/1.73m2). Patients underwent a kidney biopsy and diffusion-weighted magnetic resonance imaging within one week of biopsy; median follow-up of 2.2 years with measured laboratory parameters. The primary outcome was a rapid decline of kidney function (eGFR decline over 30% or dialysis initiation) during follow up. Significantly, patients with a negative ΔADC had 5.4 times more risk of rapid decline of kidney function or dialysis (95% confidence interval: 2.29-12.58). After correction for kidney function at baseline and proteinuria, low ADC still predicted significant kidney function loss with a hazard ratio of 4.62 (95% confidence interval 1.56-13.67) independent of baseline age, sex, eGFR and proteinuria. Thus, low ΔADC can be a predictor of kidney function decline and dialysis initiation in patients with native kidney disease or kidney allograft, independent of baseline kidney function and proteinuria.


Assuntos
Rim , Insuficiência Renal Crônica , Aloenxertos/diagnóstico por imagem , Aloenxertos/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Fibrose , Taxa de Filtração Glomerular , Humanos , Rim/patologia , Masculino , Estudos Prospectivos , Proteinúria/diagnóstico por imagem , Proteinúria/etiologia , Proteinúria/patologia , Insuficiência Renal Crônica/diagnóstico por imagem , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/cirurgia
2.
J Hepatol ; 74(3): 742-747, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33276028

RESUMO

Portopulmonary hypertension is a rare but serious complication of portal hypertension or portosystemic shunting. Portopulmonary hypertension is an indication for liver transplantation or shunt closure. However, liver transplantation is contraindicated in patients with severe pulmonary arterial hypertension. Reported mortality rates are high in children with portopulmonary hypertension and there are scarce recommendations on its management. Our aim was to report on our real-world experience of managing portopulmonary hypertension in a specialised centre. We describe a series of 6 children with portopulmonary hypertension. Their median age at diagnosis was 13 years (range 10-15). The underlying liver conditions were cirrhosis of unknown origin (1), congenital portocaval shunts (3), biliary atresia (1), and portal vein cavernoma with surgical mesenterico-caval shunt (1). Median mean pulmonary arterial pressure was 47 mmHg (range 32-70), and median pulmonary vascular resistance was 6.6 Wood units (range 4.3-15.4). All patients except one were treated with a combination of pulmonary arterial hypertension-specific therapy (phosphodiesterase type 5 inhibitors and/or endothelin receptor antagonists and/or prostacyclin analogues). Three patients then benefited from shunt closure and the others underwent liver transplantation. Five patients showed improvement or stabilisation of pulmonary arterial hypertension with no deaths after a mean follow-up of 39 months. Based on our limited experience, early and aggressive treatment with a combination of pulmonary arterial hypertension-specific therapy significantly improves patients' haemodynamic profile and enables the performance of liver transplantation and shunt closure with satisfactory outcomes.


Assuntos
Anti-Hipertensivos/uso terapêutico , Antagonistas dos Receptores de Endotelina/uso terapêutico , Epoprostenol/uso terapêutico , Hipertensão Portal/complicações , Hipertensão Portal/tratamento farmacológico , Cirrose Hepática/complicações , Transplante de Fígado/métodos , Inibidores da Fosfodiesterase 5/uso terapêutico , Derivação Portossistêmica Cirúrgica/métodos , Hipertensão Arterial Pulmonar/complicações , Hipertensão Arterial Pulmonar/tratamento farmacológico , Adolescente , Criança , Feminino , Seguimentos , Humanos , Hipertensão Portal/cirurgia , Masculino , Veia Porta/fisiopatologia , Hipertensão Arterial Pulmonar/cirurgia , Resultado do Tratamento
3.
Nephrol Dial Transplant ; 35(6): 937-945, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30608554

RESUMO

BACKGROUND: Kidney cortical interstitial fibrosis (IF) is highly predictive of renal prognosis and is currently assessed by the evaluation of a biopsy. Diffusion magnetic resonance imaging (MRI) is a promising tool to evaluate kidney fibrosis via the apparent diffusion coefficient (ADC), but suffers from inter-individual variability. We recently applied a novel MRI protocol to allow calculation of the corticomedullary ADC difference (ΔADC). We here present the validation of ΔADC for fibrosis assessment in a cohort of 164 patients undergoing biopsy and compare it with estimated glomerular filtration rate (eGFR) and other plasmatic parameters for the detection of fibrosis. METHODS: This monocentric cross-sectional study included 164 patients undergoing renal biopsy at the Nephrology Department of the University Hospital of Geneva between October 2014 and May 2018. Patients underwent diffusion-weighted imaging, and T1 and T2 mappings, within 1 week after biopsy. MRI results were compared with gold standard histology for fibrosis assessment. RESULTS: Absolute cortical ADC or cortical T1 values correlated poorly to IF assessed by the biopsy, whereas ΔADC was highly correlated to IF (r=-0.52, P < 0.001) and eGFR (r = 0.37, P < 0.01), in both native and allograft patients. ΔT1 displayed a lower, but significant, correlation to IF and eGFR, whereas T2 did not correlate to IF nor to eGFR. ΔADC, ΔT1 and eGFR were independently associated with kidney fibrosis, and their combination allowed detection of extensive fibrosis with good specificity. CONCLUSION: ΔADC is better correlated to IF than absolute cortical or medullary ADC values. ΔADC, ΔT1 and eGFR are independently associated to IF and allow the identification of patients with extensive IF.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Fibrose/diagnóstico , Córtex Renal/patologia , Nefropatias/diagnóstico , Medula Renal/patologia , Estudos Transversais , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Curva ROC
5.
MAGMA ; 33(1): 177-195, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31676990

RESUMO

OBJECTIVES: Standardization is an important milestone in the validation of DWI-based parameters as imaging biomarkers for renal disease. Here, we propose technical recommendations on three variants of renal DWI, monoexponential DWI, IVIM and DTI, as well as associated MRI biomarkers (ADC, D, D*, f, FA and MD) to aid ongoing international efforts on methodological harmonization. MATERIALS AND METHODS: Reported DWI biomarkers from 194 prior renal DWI studies were extracted and Pearson correlations between diffusion biomarkers and protocol parameters were computed. Based on the literature review, surveys were designed for the consensus building. Survey data were collected via Delphi consensus process on renal DWI preparation, acquisition, analysis, and reporting. Consensus was defined as ≥ 75% agreement. RESULTS: Correlations were observed between reported diffusion biomarkers and protocol parameters. Out of 87 survey questions, 57 achieved consensus resolution, while many of the remaining questions were resolved by preference (65-74% agreement). Summary of the literature and survey data as well as recommendations for the preparation, acquisition, processing and reporting of renal DWI were provided. DISCUSSION: The consensus-based technical recommendations for renal DWI aim to facilitate inter-site harmonization and increase clinical impact of the technique on a larger scale by setting a framework for acquisition protocols for future renal DWI studies. We anticipate an iterative process with continuous updating of the recommendations according to progress in the field.


Assuntos
Biomarcadores/metabolismo , Imagem de Difusão por Ressonância Magnética , Rim/diagnóstico por imagem , Pesquisa Translacional Biomédica , Algoritmos , Consenso , Técnica Delphi , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Rim/metabolismo , Modelos Estatísticos , Movimento (Física) , Reprodutibilidade dos Testes , Inquéritos e Questionários
6.
Magn Reson Med ; 81(1): 583-593, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30146728

RESUMO

PURPOSE: To demonstrate that diffusion-weighted images should be acquired at the instant of maximum blood velocity in kidneys to extract the perfusion fraction (PF) by the bi-exponential intravoxel incoherent motion model. METHODS: The PF values were measured in Monte-Carlo simulations corresponding to different blood velocities with a constant known PF. The distribution of the measured PF values (PF-distribution) was characterized quantitatively by 3 markers highlighting the deviation of the measurement from the true PF. Diffusion-weighted images of kidneys were acquired in 10 healthy volunteers at the instant of maximal respectively minimal blood velocity in the renal artery (Vmax versus Vmin acquisition). The PF-distributions measured from the Vmax and Vmin acquisitions were compared mutually and with simulated PF-distributions using the 3 markers. A radiologist evaluated the quality of the PF maps. RESULTS: The PF-distributions measured in the simulations were spread around the true PF value, and spreading was reduced as blood velocity increased. A comparison between simulated and in vivo PF-distributions suggests that a similar phenomenon is plausible in vivo. The quality of the PF maps of the Vmax -acquisition was scored higher by the radiologist than those of the Vmin -acquisition in 95% of cases (19 of 20). CONCLUSIONS: The PF maps are of better quality when the Vmax -acquisition is used. We show evidence supporting the hypothesis that the variation of PF along the cardiac cycle is due to oscillations between a poor estimation when the blood velocity is low, and a better estimation when blood velocity is higher.


Assuntos
Velocidade do Fluxo Sanguíneo , Imagem de Difusão por Ressonância Magnética , Processamento de Imagem Assistida por Computador/métodos , Rim/diagnóstico por imagem , Movimento (Física) , Adulto , Algoritmos , Simulação por Computador , Feminino , Voluntários Saudáveis , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Método de Monte Carlo , Perfusão , Adulto Jovem
7.
Eur Radiol ; 29(1): 251-258, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29948082

RESUMO

OBJECTIVES: Correct device sizing for left atrial appendage (LAA) closure remains challenging due to complex LAA shapes. The aim of our study was to investigative the utility of personalized 3D-printed models (P3DPM) of the LAA to guide device size selection. METHODS: Fifteen patients (75.4 ±8.5years) scheduled for LAA closure using an Amulet device underwent cardiac computed tomography (CT). The LAA was segmented by semiautomatic algorithms using Vitrea® software. A 1.5-mm LAA thick shell was exported in stereolithography format and printed using TangoPlus flexible material. Different Amulet device sizes on the P3DPM were tested. New P3DPM-CT with the device was acquired in order to appreciate the proximal disc sealing the LAA ostium and the compression of the distal lobe within the LAA. We predicted the device size with P3DPM and compared this with the device sizes predicted by transesophageal echocardiography (TEE) and CT as well as the device size implanted in patients. RESULTS: The device size predicted by 3D-TEE and CT corresponded to the implanted device size in 8/15 (53%) and 10/15 (67%), respectively. The predicted device size from the P3DPM was accurate in all patients, obtaining perfect contact with the LAA wall, without device instability or excessive compression. P3DPM-CT with the deployed device showed device deformation and positioning of the disk in relation to the pulmonary veins, allowing us to determine the best device size in all 15 cases. CONCLUSION: P3DPM allowed us to simulate the LAA closure procedure and thus helped to identify the best Amulet size and position within the LAA. KEY POINTS: • A 3D-printed heart model allows to simulate the LAA closure procedure. • A 3D-printed heart model allowed to identify the optimal Amulet size and position. • 3D-printed heart models may contribute to reduce the Amulet implantation learning curve.


Assuntos
Apêndice Atrial/cirurgia , Fibrilação Atrial/cirurgia , Modelos Cardiovasculares , Impressão Tridimensional , Idoso , Apêndice Atrial/diagnóstico por imagem , Fibrilação Atrial/diagnóstico por imagem , Cateterismo Cardíaco , Ecocardiografia Tridimensional , Ecocardiografia Transesofagiana/métodos , Feminino , Átrios do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Modelagem Computacional Específica para o Paciente , Próteses e Implantes , Desenho de Prótese
8.
Nephrol Dial Transplant ; 33(suppl_2): ii29-ii40, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30137580

RESUMO

Diffusion-weighted magnetic resonance imaging (DWI) is a non-invasive method sensitive to local water motion in the tissue. As a tool to probe the microstructure, including the presence and potentially the degree of renal fibrosis, DWI has the potential to become an effective imaging biomarker. The aim of this review is to discuss the current status of renal DWI in diffuse renal diseases. DWI biomarkers can be classified in the following three main categories: (i) the apparent diffusion coefficient-an overall measure of water diffusion and microcirculation in the tissue; (ii) true diffusion, pseudodiffusion and flowing fraction-providing separate information on diffusion and perfusion or tubular flow; and (iii) fractional anisotropy-measuring the microstructural orientation. An overview of human studies applying renal DWI in diffuse pathologies is given, demonstrating not only the feasibility and intra-study reproducibility of DWI but also highlighting the need for standardization of methods, additional validation and qualification. The current and future role of renal DWI in clinical practice is reviewed, emphasizing its potential as a surrogate and monitoring biomarker for interstitial fibrosis in chronic kidney disease, as well as a surrogate biomarker for the inflammation in acute kidney diseases that may impact patient selection for renal biopsy in acute graft rejection. As part of the international COST (European Cooperation in Science and Technology) action PARENCHIMA (Magnetic Resonance Imaging Biomarkers for Chronic Kidney Disease), aimed at eliminating the barriers to the clinical use of functional renal magnetic resonance imaging, this article provides practical recommendations for future design of clinical studies and the use of renal DWI in clinical practice.


Assuntos
Biomarcadores/análise , Imagem de Difusão por Ressonância Magnética/métodos , Rim/patologia , Guias de Prática Clínica como Assunto/normas , Insuficiência Renal Crônica/fisiopatologia , Humanos
9.
Nephrol Dial Transplant ; 33(suppl_2): ii4-ii14, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30137584

RESUMO

Functional renal magnetic resonance imaging (MRI) has seen a number of recent advances, and techniques are now available that can generate quantitative imaging biomarkers with the potential to improve the management of kidney disease. Such biomarkers are sensitive to changes in renal blood flow, tissue perfusion, oxygenation and microstructure (including inflammation and fibrosis), processes that are important in a range of renal diseases including chronic kidney disease. However, several challenges remain to move these techniques towards clinical adoption, from technical validation through biological and clinical validation, to demonstration of cost-effectiveness and regulatory qualification. To address these challenges, the European Cooperation in Science and Technology Action PARENCHIMA was initiated in early 2017. PARENCHIMA is a multidisciplinary pan-European network with an overarching aim of eliminating the main barriers to the broader evaluation, commercial exploitation and clinical use of renal MRI biomarkers. This position paper lays out PARENCHIMA's vision on key clinical questions that MRI must address to become more widely used in patients with kidney disease, first within research settings and ultimately in clinical practice. We then present a series of practical recommendations to accelerate the study and translation of these techniques.


Assuntos
Biomarcadores/análise , Imageamento por Ressonância Magnética/métodos , Insuficiência Renal Crônica/classificação , Insuficiência Renal Crônica/patologia , Progressão da Doença , Humanos , Insuficiência Renal Crônica/terapia
10.
Kidney Int ; 101(5): 1083-1084, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35461596
11.
J Magn Reson Imaging ; 46(6): 1631-1640, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28295820

RESUMO

PURPOSE: To compare readout-segmented echo-planar imaging (EPI) (RESOLVE) to single-shot EPI (ss-EPI) diffusion-weighted imaging (DWI) for the assessment of renal interstitial fibrosis. MATERIALS AND METHODS: A phantom, eight healthy volunteers (under 30 years to avoid age-fibrosis related) and 27 chronic kidney disease (CKD) patients (scheduled for kidney biopsy) were scanned (at 3T) with ss-EPI and 5-shot RESOLVE DWI (resolution: 2 × 2 × 5 mm3 , 10 b-values). The cortico-medullary difference for each DW parameter from a monoexponential fit (ΔADC) or, segmented biexponential fit (ΔD, ΔD*, ΔFp ) were compared between both sequences. A fibrosis threshold of 40% was defined to separate all 35 subjects into low and high fibrosis groups. The linear relationship between DW parameters and percentage fibrosis (up to 80%) from Masson trichrome was assessed with the Pearson product-moment correlation coefficient. Fisher Z-transform was used for R2 correlation comparison. RESULTS: A coefficient of variation between ADCs of 3% was measured between both sequences in the phantom. In healthy volunteers, no significant difference was measured for all DW parameters. Both sequences separated low to high level of fibrosis with a significant decrease of ΔADC (RESOLVE P = 3.1 × 10-6 , ss-EPI P = 0.003) and ΔD (RESOLVE P = 8.2 × 10-5 , ss-EPI P = 0.02) in the high level of fibrosis. However, RESOLVE ΔADC had a stronger negative correlation (P = 0.04 for R2 comparison) with fibrosis than ss-EPI ΔADC (RESOLVE R2 = 0.65, P = 5.9 × 10-9 , ss-EPI R2 = 0.29, P = 8.9 × 10-4 ). ΔD (RESOLVE) was correlated (moderately) with fibrosis (R2 = 0.29, P = 9.2 × 10-4 ); however, ΔD* and ΔFp did not show, in our population, a significant correlation with interstitial fibrosis (0.01 < R2 < 0.08). CONCLUSION: ΔADC derived from both sequences correlated with fibrosis. ΔADC from RESOLVE showed better correlation with fibrosis than ΔADC from ss-EPI and therefore has potential to monitor CKD. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1631-1640.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Interpretação de Imagem Assistida por Computador/métodos , Nefropatias/diagnóstico por imagem , Nefropatias/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fibrose , Humanos , Rim/diagnóstico por imagem , Rim/patologia , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Reprodutibilidade dos Testes
12.
Urol Int ; 98(1): 7-14, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27784024

RESUMO

INTRODUCTION: The study aimed to evaluate 3 different modalities of transrectal ultrasound (TRUS)-guided prostate biopsies (PBs; 2D-, 3D- and targeted 3D-TRUS with fusion to MRI - T3D). Primary end point was the detection rate of prostate cancer (PC). Secondary end point was the detection rate of insignificant PC according to the Epstein criteria. PATIENTS AND METHODS: Inclusion of 284 subsequent patients who underwent 2D-, 3D- or T3D PB from 2011 to 2015. All patients having PB for initial PC detection with a serum prostate-specific antigen value ≤20 ng/ml were included. Patients with T4 and/or clinical and/or radiological metastatic disease, so as these under active surveillance were excluded. RESULTS: Patients with T3D PB had a significantly higher detection rate of PC (58 vs. 19% for 2D and 38% for 3D biopsies; p = 0.001), with no difference in Gleason score distribution (p = 0.644), as well as detection rate of low-risk cancers (p = 0.914). Main predictive factor for positive biopsies was the technique used, with respectively a 3- and 8-fold higher detection rate in the 3D- and T3D group. For T3D-PB, there was a significant correlation between radiological cancer suspicion (Prostate Imaging Reporting and Data System Score) and cancer detection rate (p = 0.02). CONCLUSIONS: T3D PB should be preferred over 2D PB and 3D PB in patients with suspected PC as it improves the cancer detection rate.


Assuntos
Imageamento Tridimensional , Imageamento por Ressonância Magnética , Próstata/diagnóstico por imagem , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Ultrassonografia de Intervenção , Idoso , Humanos , Biópsia Guiada por Imagem/métodos , Masculino , Pessoa de Meia-Idade , Reto , Estudos Retrospectivos
14.
J Mol Cell Cardiol ; 94: 82-94, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27056420

RESUMO

Selective pharmacological treatments targeting reperfusion injury produced modest protective effects and might be associated with immunosuppression. In order to identify novel and better-tolerated approaches, we focused on the neutralization of receptor activator of nuclear factor kappa-B ligand [RANKL], a cytokine recently shown to activate inflammatory cells (i.e. neutrophils) orchestrating post-infarction injury and repair. Myocardial ischemia (60min) and reperfusion injury was surgically induced in C57Bl/6 mice. In hearts and serum, RANKL was early upregulated during reperfusion. A "one-shot" injection with neutralizing anti-RANKL IgG during ischemia ameliorated myocardial infarct size and function, but not adverse remodeling (determined by Magnetic Resonance Imaging [MRI]) as compared to Vehicle or control IgG. These beneficial effects were accompanied in vivo by reduction in cardiac neutrophil infiltration, reactive oxygen species (ROS) and MMP-9 release. Anti-RANKL IgG treatment suppressed sudden peak of neutrophil granule products in mouse serum early after reperfusion onset. In vitro, RANK mRNA expression was detected in isolated mouse neutrophils. Co-incubation with neutralizing anti-RANKL IgG abrogated RANKL-induced mouse neutrophil degranulation and migration, suggesting a critical role of RANKL in neutrophil-mediated injury. Conversely, anti-RANKL IgG did not affect salvage pathways in cardiac cells (i.e. ERK p42/p44, Akt and STAT-3) or macrophage cardiac infiltration. Finally, treatment with anti-RANKL IgG showed no effect on B and T lymphocyte polarization (in serum, spleen and infarcted myocardium) and circulating chemokines as compared with Vehicle or control IgG. In conclusion, acute treatment with anti-RANKL IgG improved cardiac infarct size and function by potentially impacting on neutrophil-mediated injury and repair.


Assuntos
Anticorpos Monoclonais/farmacologia , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Neutrófilos/efeitos dos fármacos , Ligante RANK/antagonistas & inibidores , Disfunção Ventricular/tratamento farmacológico , Animais , Biomarcadores , Degranulação Celular , Citocinas/sangue , Citocinas/metabolismo , Modelos Animais de Doenças , Mediadores da Inflamação/sangue , Mediadores da Inflamação/metabolismo , Subpopulações de Linfócitos/patologia , Macrófagos/patologia , Imageamento por Ressonância Magnética , Masculino , Camundongos , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/etiologia , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Infiltração de Neutrófilos , Neutrófilos/imunologia , Neutrófilos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ligante RANK/metabolismo , Troponina I/sangue , Troponina I/metabolismo
15.
J Magn Reson Imaging ; 44(3): 601-9, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26914964

RESUMO

PURPOSE: To assess the influence of perfusion on apparent coefficient diffusion (ADC) maps, the contribution of b-value images, and the number of b-values needed in prostate cancer detection by diffusion-weighted imaging (DWI). MATERIALS AND METHODS: Patients scheduled for prostatectomy were scanned by 3T magnetic resonance imaging (MRI) with DWI based on b-values 0-500-1000-1500 s/mm(2) . A monoexponential model was fitted to obtain ADC using multiple b-values, with or without b0 (perfusion-sensitive ADC4b-b0-500-1000-1500 , perfusion-insensitive ADC3b-b500-1000-1500 ), or two b-values (ADC2b-b0-500 , ADC2b-b0-1000 , ADC2b-b0-1500 ). Prostate and cancer foci were segmented to label voxels as normal or tumoral, according to histology. Areas under receiver operating characteristic curves (AUC) were calculated for each ADC and b-value, then for multivariate logistic regression models combining them. A threshold of 85 tumoral voxels (=0.5 cm(3) ) was used to stratify AUC analysis. RESULTS: In all, 21 patients were selected. Segmentation collected 143,665 prostatic voxels including 10,069 tumoral voxels. In five patients, tumor segmentation provided fewer than 85 voxels, resulting in an ADC with AUC inferior to 0.52. In 16 patients with larger tumors, perfusion-sensitive ADC4b-b0-500-1000-1500 performed better than perfusion-insensitive ADC3b-b500-1000-1500 and similar to ADC2b-b0-1500 (AUC of 0.840, 0.809, and 0.838, respectively). In comparison to the ADC alone, models combining ADC4b-b0-500-1000-1500 or ADC2b-b0-1500 with b1500 improved performance, leading to similar AUCs of 0.884 and 0.883, respectively. In both models, ADC and b1500 were significant markers (P < 0.001). CONCLUSION: Including b0 in ADC calculation provided superior ADC maps for prostate cancer detection. b1500 images as a combined parameter with ADC also improved performance. Using more than two b-values showed no improvement. J. Magn. Reson. Imaging 2016;44:601-609.


Assuntos
Algoritmos , Imagem de Difusão por Ressonância Magnética/métodos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/patologia , Idoso , Imagem de Difusão por Ressonância Magnética/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Acta Oncol ; 55(7): 834-8, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26796870

RESUMO

Background The dosimetric advantage of prostate-rectum spacers to displace the anterior rectal wall outside of the high-dose radiation regions has been clearly established in prostate cancer radiotherapy (RT). The aim of this study was to assess the impact of hydrogel spacer (HS) in the interfraction prostate motion in patients undergoing RT for prostate cancer. Material and methods Twenty prostate cancer patients implanted with three fiducial markers (FM) with (n = 10) or without (n = 10) HS were analyzed. Displacements between the prostate isocenter based on the FM's position and the bony anatomy were quantified in the left-right (LR), anterior-posterior (AP), superior-inferior (SI) axes by offline analyses of 122 cone beam computed tomography scans. Group systematic (M), systematic (Σ) and random (σ) setup errors were determined. Results In patients with or without HS, the overall mean interfraction prostate displacements were 0.4 versus -0.4 mm (p = 0.0001), 0.6 versus 0.6 mm (p = 0.85), and -0.6 mm versus -0.3 mm (p = 0.48) for the LR, AP, and SI axes, respectively. Prostate displacements >5 mm in the AP and SI directions were similar for both groups. No differences in M, Σ and σ setup errors were observed in the three axes between HS + or HS- patients. Conclusions HS implantation does not significantly influence the interfraction prostate motion in patients treated with RT for prostate cancer. The major expected benefit of HS is a reduction of the high-dose levels to the rectal wall without influence in prostate immobilization.


Assuntos
Marcadores Fiduciais , Hidrogel de Polietilenoglicol-Dimetacrilato/administração & dosagem , Neoplasias da Próstata/radioterapia , Radioterapia Guiada por Imagem/métodos , Idoso , Idoso de 80 Anos ou mais , Fracionamento da Dose de Radiação , Humanos , Injeções , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Neoplasias da Próstata/diagnóstico por imagem , Planejamento da Radioterapia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos
18.
Eur Heart J ; 36(8): 516-26a, 2015 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-25336219

RESUMO

AIMS: Several intracellular mediators have been implicated as new therapeutic targets against myocardial ischaemia and reperfusion injury. However, clinically effective salvage pathways remain undiscovered. Here, we focused on the potential role of the adaptor protein p66(Shc) as a regulator of myocardial injury in a mouse model of cardiac ischaemia and reperfusion. METHODS AND RESULTS: Adult male p66(Shc) deficient (p66(Shc) (-/-)) and C57Bl/6 wild-type (WT) mice were exposed to 30, 45, or 60 min of ischaemia and reperfusion (5, 15 min, or 24 h). Infarct size, systemic and intracardiac inflammation and oxidants, as well as cytosolic and mitochondrial apoptotic pathways were investigated. Following 30, but not 45 or 60 min of ischaemia, genetic p66(Shc) deficiency was associated with larger infarcts. In WT mice, in vivo p66(Shc) knock down by siRNA with transient protein deficiency confirmed these findings. P66(Shc) inhibition was not associated with any modification in post-infarction inflammation, oxidative burst nor cardiac vessel density or structure. However, in p66(Shc) (-/-) mice activation of the protective and anti-apoptotic Reperfusion Injury Salvage Kinases and Survivor Activating Factor Enhancement pathways were blunted and mitochondrial swelling and cellular apoptosis via the caspase-3 pathway increased compared with WT. CONCLUSIONS: Genetic deletion of p66(Shc) increased susceptibility to myocardial injury in response to short-term ischaemia and reperfusion in mice. Still, additional studies are needed for assessing the role of this pathway in acute coronary syndrome patients.


Assuntos
Deleção de Genes , Traumatismo por Reperfusão Miocárdica/genética , Proteínas Adaptadoras da Sinalização Shc/genética , Animais , Apoptose/genética , Biomarcadores/metabolismo , Técnicas de Silenciamento de Genes , Sistema de Sinalização das MAP Quinases/genética , Masculino , Camundongos Endogâmicos C57BL , Dilatação Mitocondrial/genética , Reperfusão Miocárdica/métodos , Traumatismo por Reperfusão Miocárdica/patologia , Miocárdio/metabolismo , Fator de Transcrição STAT3/genética , Proteínas Adaptadoras da Sinalização Shc/deficiência , Proteínas Adaptadoras da Sinalização Shc/metabolismo , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Troponina I/metabolismo
20.
J Hepatol ; 61(2): 278-85, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24713189

RESUMO

BACKGROUND & AIMS: Liver transplantation from marginal donors is associated with ischemia/reperfusion (I/R) lesions, which may increase the risk of post-transplant hepatocellular carcinoma (HCC) recurrence. Graft reperfusion prior to retrieval (as for extracorporeal membrane oxygenation--ECMO) can prevent I/R lesions. The impact of I/R on the risk of cancer recurrence was assessed on a syngeneic Fischer-rat liver transplantation model. METHODS: HCC cells were injected into the vena porta of all recipients at the end of an orthotopic liver transplantation (OLT). Control donors were standard heart-beating, ischemic ones (ISC), underwent 10 min or 30 min inflow liver clamping prior to retrieval, and ischemic/reperfused (ISC/R) donors underwent 2h liver reperfusion after the clamping. RESULTS: I/R lesions were confirmed in the ISC group, with the presence of endothelial and hepatocyte injury, and increased liver function tests. These lesions were in part reversed by the 2h reperfusion in the ISC/R group. HCC growth was higher in the 10 min and 30 min ISC recipients (p = 0.018 and 0.004 vs. control, as assessed by MRI difference between weeks one and two), and was prevented in the ISC/Rs (p = 0.04 and 0.01 vs. ISC). These observations were associated with a stronger pro-inflammatory cytokine profile in the ISC recipients only, and the expression of hypoxia and HCC growth-enhancer genes, including Hmox1, Hif1a and Serpine1. CONCLUSIONS: This experiment suggests that ischemia/reperfusion lesions lead to an increased risk of post-transplant HCC recurrence and growth. This observation can be reversed by graft reperfusion prior to retrieval.


Assuntos
Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/cirurgia , Transplante de Fígado/efeitos adversos , Fígado/irrigação sanguínea , Recidiva Local de Neoplasia/prevenção & controle , Traumatismo por Reperfusão/complicações , Animais , Carcinoma Hepatocelular/patologia , Heme Oxigenase (Desciclizante)/genética , Interleucina-6/sangue , Neoplasias Hepáticas/patologia , Imageamento por Ressonância Magnética , Masculino , Ratos , Ratos Endogâmicos F344 , Reperfusão , Serotonina/sangue
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