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1.
J Clin Med ; 12(8)2023 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-37109291

RESUMEN

Renal fibrosis is an important marker in the progression of chronic kidney disease, and renal biopsy is the current reference standard for detecting its presence. Currently, non-invasive methods have only been partially successful in detecting renal fibrosis. Magnetization transfer imaging (MTI) allows estimates of renal fibrosis but may vary with scanning conditions. We hypothesized that MTI-derived renal fibrosis would be reproducible at 1.5T and 3T MRI and over time in fibrotic kidneys. Fifteen pigs with unilateral renal artery stenosis (RAS, n = 9) or age-matched sham controls (n = 6) underwent MTI-MRI at both 1.5T and 3T 6 weeks post-surgery and again 4 weeks later. Magnetization transfer ratio (MTR) measurements of fibrosis in both kidneys were compared between 1.5T and 3T, and the reproducibility of MTI at the two timepoints was evaluated at 1.5T and 3T. MTR at 3T with 600 Hz offset frequency successfully distinguished between normal, stenotic, and contralateral kidneys. There was excellent reproducibility of MTI at 1.5T and 3T over the two timepoints and no significant differences between MTR measurements at 1.5T and 3T. Therefore, MTI is a highly reproducible technique which is sensitive to detect changes in fibrotic compared to normal kidneys in the RAS porcine model at 3T.

2.
Radiol Case Rep ; 18(3): 1324-1328, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36704366

RESUMEN

Ganglioneuromas are benign neuroblastic tumors seen most in pediatric population. The most common locations are mediastinal, retroperitoneal and adrenal regions. Ganglioneuromas rarely occur in presacral space. We present one such case of an incidentally diagnosed presacral ganglioneuroma in an asymptomatic 71-year-old male who initially presented with hematuria.

4.
Invest Radiol ; 57(5): 334-342, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-34935650

RESUMEN

OBJECTIVES: Quantitative magnetization transfer (qMT) is useful for measurement of murine renal fibrosis at high and ultrahigh field strengths. However, its utility at clinical field strengths and in human-like kidneys remains unknown. We tested the hypothesis that qMT would successfully detect fibrosis in swine kidneys with unilateral renal artery stenosis (RAS) at 3.0 T. METHODS: The qMT protocol is composed of MT scans with variable flip angles and offset frequencies, and of B0, B1, and T1 mapping. Pigs were scanned 10 weeks after RAS or control. A 2-pool model was used to fit the bound pool fraction f of the renal cortex (CO) and outer medulla (OM). Then qMT-derived f in 5 normal and 10 RAS pigs was compared with histological fibrosis determined using Masson's trichrome staining and to renal perfusion assessed with computed tomography. RESULTS: The qMT 2-pool model provided accurate fittings of data collected on swine kidneys. Stenotic kidneys showed significantly elevated f in both the CO (9.8% ± 2.7% vs 6.4% ± 0.9%, P = 0.002) and OM (7.6% ± 2.2% vs 4.7% ± 1.1%, P = 0.002), as compared with normal kidneys. Histology-measured renal fibrosis and qMT-derived f correlated directly in both the cortex (Pearson correlation coefficient r = 0.93, P < 0.001) and OM (r = 0.84, P = 0.002), and inversely with stenotic kidney perfusion (r = 0.85, P = 0.002). CONCLUSIONS: This study demonstrates the feasibility of qMT for measuring fibrosis in human-like swine kidneys, and the association between tissue macromolecule content and renal perfusion. Therefore, qMT may be useful as a tool for noninvasive assessment of renal fibrosis in subjects with RAS at clinical field strengths.


Asunto(s)
Imagen por Resonancia Magnética , Obstrucción de la Arteria Renal , Animales , Fibrosis , Humanos , Riñón/diagnóstico por imagen , Riñón/patología , Imagen por Resonancia Magnética/métodos , Ratones , Obstrucción de la Arteria Renal/diagnóstico por imagen , Obstrucción de la Arteria Renal/patología , Porcinos
5.
Acta Radiol Open ; 10(9): 20584601211044989, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34603747

RESUMEN

IgG4-related disease was originally discovered in patients with autoimmune pancreatitis accompanied by elevated serum IgG4 levels and has subsequently been described in almost every organ system. IgG4-related disease presents with a variety of symptoms according to the organ affected and may be accompanied by serious complications such as organ dysfunction associated with IgG4-positive cell proliferation. We report a case of IgG4-related abdominal disease in a patient who also had involvement of the coronary artery.

6.
Invest Radiol ; 56(2): 86-93, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33405430

RESUMEN

MATERIALS AND METHODS: Stenotic kidney (STK) and contralateral kidney magnetization transfer ratios (MTRs; Mt/M0) were measured at 3.0-T magnetic resonance imaging, at offset frequencies of 600 and 1000 Hz, before and 1 month post-PTRA in 7 RVD pigs. Stenotic kidney MTR was correlated to renal perfusion, renal blood flow (RBF), and glomerular filtration rate (GFR), determined using multidetector computed tomography and with ex vivo renal fibrosis (trichrome staining). Untreated RVD (n = 6) and normal pigs (n = 7) served as controls. RESULTS: Renovascular disease induced hypertension and renal dysfunction. Blood pressure and renal perfusion were unchanged post-PTRA, but GFR and RBF increased. Baseline cortical STK-MTR predicted post-PTRA renal perfusion and RBF, and MTR changes associated inversely with changes in perfusion and normalized GFR. Stenotic kidney MTR at 600 Hz showed closer association with renal parameters, but both frequencies predicted post-PTRA cortical fibrosis. CONCLUSIONS: Renal STK-MTR, particularly at 600 Hz offset, is sensitive to hemodynamic changes after PTRA in swine RVD and capable of noninvasively predicting post-PTRA kidney perfusion, RBF, and fibrosis. Therefore, STK-MTR may be a valuable tool to predict renal hemodynamic and functional recovery, as well as residual kidney fibrosis after revascularization in RVD.


Asunto(s)
Obstrucción de la Arteria Renal , Animales , Tasa de Filtración Glomerular , Riñón/diagnóstico por imagen , Riñón/cirugía , Imagen por Resonancia Magnética , Obstrucción de la Arteria Renal/diagnóstico por imagen , Obstrucción de la Arteria Renal/cirugía , Circulación Renal , Porcinos
7.
J Inherit Metab Dis ; 44(2): 502-514, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-32677106

RESUMEN

BACKGROUND: (+)-Epicatechin (EPI) induces mitochondrial biogenesis and antioxidant metabolism in muscle fibers and neurons. We aimed to evaluate safety and efficacy of (+)-EPI in pediatric subjects with Friedreich's ataxia (FRDA). METHODS: This was a phase II, open-label, baseline-controlled single-center trial including 10 participants ages 10 to 22 with confirmed FA diagnosis. (+)-EPI was administered orally at 75 mg/d for 24 weeks, with escalation to 150 mg/d at 12 weeks for subjects not showing improvement of neuromuscular, neurological or cardiac endpoints. Neurological endpoints were change from baseline in Friedreich's Ataxia Rating Scale (FARS) and 8-m timed walk. Cardiac endpoints were changes from baseline in left ventricular (LV) structure and function by cardiac magnetic resonance imaging (MRI) and echocardiogram, changes in cardiac electrophysiology, and changes in biomarkers for heart failure and hypertrophy. RESULTS: Mean FARS/modified (m)FARS scores showed nonstatistically significant improvement by both group and individual analysis. FARS/mFARS scores improved in 5/9 subjects (56%), 8-m walk in 3/9 (33%), 9-peg hole test in 6/10 (60%). LV mass index by cardiac MRI was significantly reduced at 12 weeks (P = .045), and was improved in 7/10 (70%) subjects at 24 weeks. Mean LV ejection fraction was increased at 24 weeks (P = .008) compared to baseline. Mean maximal septal thickness by echocardiography was increased at 24 weeks (P = .031). There were no serious adverse events. CONCLUSION: (+)-EPI was well tolerated over 24 weeks at up to 150 mg/d. Improvement was observed in cardiac structure and function in subset of subjects with FRDA without statistically significant improvement in primary neurological outcomes. SYNOPSIS: A (+)-epicatechin showed improvement of cardiac function, nonsignificant reduction of FARS/mFARS scores, and sustained significant upregulation of muscle-regeneration biomarker follistatin.


Asunto(s)
Antioxidantes/administración & dosificación , Catequina/administración & dosificación , Ataxia de Friedreich/tratamiento farmacológico , Corazón/diagnóstico por imagen , Adolescente , Niño , Ecocardiografía , Femenino , Ataxia de Friedreich/fisiopatología , Humanos , Imagen por Resonancia Magnética , Masculino , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Caminata
9.
Sci Rep ; 10(1): 16300, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-33004888

RESUMEN

Tissue fibrosis is an important index of renal disease progression. Diffusion-weighted magnetic resonance imaging's (DWI-MRI) apparent diffusion coefficient (ADC) reveals water diffusion is unobstructed by microstructural alterations like fibrosis. We hypothesized that ADC may indicate renal injury and response to therapy in patients with renovascular disease (RVD). RVD patients were treated with medical therapy (MT) and percutaneous transluminal renal angioplasty (MT + PTRA) (n = 11, 3 bilaterally, n = 14 kidneys) or MT (n = 9). ADC and renal hypoxia (R2*) by blood-oxygen-level-dependent MRI were studied before (n = 27) and 3 months after (n = 20) treatment. Twelve patients underwent renal biopsies. Baseline ADC values were correlated with changes in eGFR, serum creatinine (SCr), systolic blood pressure (SBP), renal hypoxia, and renal vein levels of pro-inflammatory marker tumor necrosis-factor (TNF)-α. Renal oxygenation, eGFR, and SCr improved after MT + PTRA. ADC inversely correlated with the histological degree of renal fibrosis, but remained unchanged after MT or MT + PTRA. Basal ADC values correlated modestly with change in SBP, but not in renal hypoxia, TNF-α levels, or renal function. Lower ADC potentially reflects renal injury in RVD patients, but does not change in response to medical or interventional therapy over 3 months. Future studies need to pinpoint indices of kidney recovery potential.


Asunto(s)
Riñón/patología , Obstrucción de la Arteria Renal/patología , Anciano , Angioplastia , Biopsia , Imagen de Difusión por Resonancia Magnética , Femenino , Fibrosis , Humanos , Riñón/diagnóstico por imagen , Masculino , Obstrucción de la Arteria Renal/diagnóstico por imagen , Obstrucción de la Arteria Renal/terapia , Resultado del Tratamiento
10.
Clin J Am Soc Nephrol ; 15(9): 1267-1278, 2020 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-32843370

RESUMEN

BACKGROUND AND OBJECTIVES: We assessed safety and efficacy of another somatostatin receptor analog, pasireotide long-acting release, in severe polycystic liver disease and autosomal dominant polycystic kidney disease. Pasireotide long-acting release, with its broader binding profile and higher affinity to known somatostatin receptors, has potential for greater efficacy. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Individuals with severe polycystic liver disease were assigned in a 2:1 ratio in a 1-year, double-blind, randomized trial to receive pasireotide long-acting release or placebo. Primary outcome was change in total liver volume; secondary outcomes were change in total kidney volume, eGFR, and quality of life. RESULTS: Of 48 subjects randomized, 41 completed total liver volume measurements (n=29 pasireotide long-acting release and n=12 placebo). From baseline, there were -99±189 ml/m absolute and -3%±7% change in annualized change in height-adjusted total liver volume (from 2582±1381 to 2479±1317 ml/m) in the pasireotide long-acting release group compared with 136±117 ml/m absolute and 6%±7% increase (from 2387±759 to 2533±770 ml/m) in placebo (P<0.001 for both). Total kidney volumes decreased by -12±34 ml/m and -1%±4% in pasireotide long-acting release compared with 21±21 ml/m and 4%±5% increase in the placebo group (P=0.05 for both). Changes in eGFR were similar between groups. Among the n=48 randomized, adverse events included hyperglycemia (26 of 33 [79%] in pasireotide long-acting release versus four of 15 [27%] in the placebo group; P<0.001), and among the 47 without diabetes at baseline, 19 of 32 (59%) in the pasireotide long-acting release group versus one of 15 (7%) in the placebo group developed diabetes (P=0.001). CONCLUSIONS: Another somatostatin analog, pasireotide long-acting release, slowed progressive increase in both total liver volume/total kidney volume growth rates without affecting GFR decline. Participants experienced higher frequency of adverse events (hyperglycemia and diabetes). CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Pasireotide LAR in Severe Polycystic Liver Disease, NCT01670110 PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2020_08_28_CJN13661119.mp3.


Asunto(s)
Quistes/tratamiento farmacológico , Riñón/efectos de los fármacos , Hepatopatías/tratamiento farmacológico , Hígado/efectos de los fármacos , Riñón Poliquístico Autosómico Dominante/tratamiento farmacológico , Somatostatina/análogos & derivados , Adulto , Quistes/patología , Progresión de la Enfermedad , Método Doble Ciego , Femenino , Tasa de Filtración Glomerular/efectos de los fármacos , Humanos , Riñón/patología , Riñón/fisiopatología , Hígado/patología , Hepatopatías/patología , Masculino , Persona de Mediana Edad , Minnesota , Tamaño de los Órganos , Riñón Poliquístico Autosómico Dominante/patología , Riñón Poliquístico Autosómico Dominante/fisiopatología , Calidad de Vida , Índice de Severidad de la Enfermedad , Somatostatina/efectos adversos , Somatostatina/uso terapéutico , Factores de Tiempo , Resultado del Tratamiento
11.
Hypertension ; 76(2): 497-505, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32507040

RESUMEN

The significance of peristenotic collateral circulation (PCC) development around a stenotic renal artery is unknown. We tested the hypothesis that PCC is linked to loss of kidney function and recovery potential in patients with atherosclerotic renovascular disease (ARVD). Thirty-four patients with ARVD were assigned to medical-therapy with or without revascularization based on clinical indications. The PCC was visualized using multidetector computed tomography and defined relative to segmental arteries in patients with essential hypertension. PCC number before and 3 months after treatment was correlated with various renal parameters. Thirty-four stenotic kidneys from 30 patients were analyzed. PCC number correlated inversely with kidney volume. ARVD-stenotic kidneys with baseline PCC (collateral ARVD [C-ARVD], n=13) associated with elevated 24-hour urine protein and stenotic kidney vein level of tumor necrosis factor-α, lower single-kidney volume and blood flow, and greater hypoxia than in stenotic kidneys with no PCC (no collateral ARVD [NC-ARVD], n=17). Revascularization (but not medical-therapy alone) improved stenotic kidney function and reduced inflammation in both NC-ARVD and C-ARVD. In C-ARVD, revascularization also increased stenotic kidney volume, blood flow, and oxygenation to levels comparable to NC-ARVD, and induced PCC regression. However, revascularization improved systolic blood pressure, plasma renin activity, and filtration fraction only in NC-ARVD. Therefore, patients with C-ARVD have greater kidney dysfunction, atrophy, hypoxia, and inflammation compared with patients with NC-ARVD, suggesting that PCC does not effectively protect the stenotic kidney in ARVD. Renal artery revascularization improved in C-ARVD stenotic kidney function, but not hypertension or renin-angiotensin system activation. These observations may help direct management of patients with ARVD.


Asunto(s)
Aterosclerosis/fisiopatología , Circulación Colateral/fisiología , Enfermedades Renales/fisiopatología , Riñón/fisiopatología , Obstrucción de la Arteria Renal/fisiopatología , Circulación Renal/fisiología , Anciano , Aterosclerosis/diagnóstico por imagen , Presión Sanguínea/fisiología , Femenino , Tasa de Filtración Glomerular/fisiología , Humanos , Riñón/diagnóstico por imagen , Enfermedades Renales/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tomografía Computarizada Multidetector , Obstrucción de la Arteria Renal/diagnóstico por imagen
12.
Plast Reconstr Surg Glob Open ; 8(4): e2805, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32440457

RESUMEN

Most magnetic resonance lymphangiography techniques employ intravenous gadolinium-based contrast agents, which carry a US Food and Drug Administration warning about gadolinium retention in the body when used intravenously. Because of this, there may be reluctance to perform intradermal injections of gadolinium-based contrast agents in patients with obstructed lymphatic drainage due to concerns about gadolinium retention in the skin and soft tissues and potential-related toxicity. The aim of this study was to show proof of concept of 2 preoperative lymphangiographic techniques that do not use gadolinium-based contrast agents. One technique used contrast-enhanced ultrasound with intradermal injections of microbubbles (Lumason) in a patient with stage 3, nonpitting left upper extremity edema. Another technique used magnetic resonance imaging with intradermal injections of 0.03 mg/mL or 0.003% ferumoxytol (Feraheme) in a patient with stage 3, nonpitting right lower extremity edema. Both contrast-enhanced ultrasound with microbubbles and magnetic resonance lymphangiogram with ferumoxytol were able to identify candidates for lymphovenous bypass surgery. These candidates were not identified by conventional indocyanine green injections. The authors conclude that (1) low-dose ferumoxytol is a potentially effective non-gadolinium-based contrast alternative to gadolinium-based contrast agent in magnetic resonance lymphangiography and (2) contrast-enhanced ultrasound can identify candidate lymphatic vessels for anastomosis.

13.
Invest New Drugs ; 38(6): 1755-1762, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32328844

RESUMEN

Purpose Combining small-molecule inhibitors of different targets was shown to be synergistic in preclinical studies. Testing this concept in clinical trials is, however, daunting due to challenges in toxicity management and efficacy assessment. This study attempted to evaluate the safety and efficacy of vatalanib plus everolimus in patients with advanced solid tumors and explore the utility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) studies as a predictive biomarker. Patients and Methods This single-center, phase I trial containing 70 evaluable patients consisted of a dose escalation proportion based on the traditional "3 + 3" design (cohort IA and IB) and a dose expansion proportion (cohort IIA and IIB). Toxicity was evaluated using the Common Terminology Criteria of Adverse Events. Antitumor activity was assessed using the Modified Response Evaluation Criteria in Solid Tumors. Results The maximum tolerated doses were determined to be vatalanib 1250 mg once daily or 750 mg twice daily in combination with everolimus 10 mg once daily. No treatment-related death occurred. The most common toxicities were hypertriglyceridemia, hypercholesterolemia, fatigue, vomiting, nausea and diarrhea. There was no complete response. Nine patients (12.9%) had partial response (PR) and 41 (58.6%) had stable disease (SD). Significant antitumor activity was observed in neuroendocrine tumors with a disease-control rate (PR + SD) of 66.7% and other tumor types including renal cancer, melanoma, and non-small-cell lung cancer. Conclusions The combination of vatalanib and everolimus demonstrated reasonable toxicity and clinical activity. Future studies combining targeted therapies and incorporating biomarker analysis are warranted based on this phase I trial.


Asunto(s)
Antineoplásicos/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Everolimus/administración & dosificación , Neoplasias/tratamiento farmacológico , Ftalazinas/administración & dosificación , Inhibidores de Proteínas Quinasas/administración & dosificación , Piridinas/administración & dosificación , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Everolimus/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ftalazinas/efectos adversos , Inhibidores de Proteínas Quinasas/efectos adversos , Piridinas/efectos adversos , Resultado del Tratamiento , Adulto Joven
14.
Kidney Int ; 97(4): 793-804, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32093917

RESUMEN

Atherosclerotic renovascular disease (ARVD) reduces tissue perfusion and eventually leads to loss of kidney function with limited therapeutic options. Here we describe results of Phase 1a escalating dose clinical trial of autologous mesenchymal stem cell infusion for ARVD. Thirty-nine patients with ARVD were studied on two occasions separated by three months. Autologous adipose-derived mesenchymal stem cells were infused through the renal artery in 21 patients at three different dose levels (1, 2.5 and 5.0 × 105 cells/kg) in seven patients each. We measured renal blood flow, glomerular filtration rate (GFR) (iothalamate and estimated GFR), renal vein cytokine levels, blood pressure, and tissue oxygenation before and three months after stem cell delivery. These indices were compared to those of 18 patients with ARVD matched for age, kidney function and blood pressure receiving medical therapy alone that underwent an identical study protocol. Cultured mesenchymal stem cells were also studied in vitro. For the entire stem cell treated-cohort, mean renal blood flow in the treated stenotic kidney significantly increased after stem cell infusion from (164 to 190 ml/min). Hypoxia, renal vein inflammatory cytokines, and angiogenic biomarkers significantly decreased following stem cell infusion. Mean systolic blood pressure significantly fell (144 to 136 mmHg) and the mean two-kidney GFR (Iothalamate) modestly but significantly increased from (53 to 56 ml/min). Changes in GFR and blood pressure were largest in the high dose stem cell treated individuals. No such changes were observed in the cohort receiving medical treatment alone. Thus, our data demonstrate the potential for autologous mesenchymal stem cell to increase blood flow, GFR and attenuate inflammatory injury in post-stenotic kidneys. The observation that some effects are dose-dependent and related to in-vitro properties of mesenchymal stem cell may direct efforts to maximize potential therapeutic efficacy.


Asunto(s)
Células Madre Mesenquimatosas , Obstrucción de la Arteria Renal , Biomarcadores , Presión Sanguínea , Tasa de Filtración Glomerular , Humanos , Riñón , Obstrucción de la Arteria Renal/terapia , Circulación Renal
15.
J Clin Imaging Sci ; 9: 6, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31448157

RESUMEN

Apparent gadolinium-based contrast enhancement was seen on precontrast-enhanced images on two breast magnetic resonance imaging (MRI) for a patient done 1 week apart. This was caused by ferumoxytol, which is used to treat some anemias. Such nongadolinium-based therapeutics exhibiting unintended MRI contrast-like properties preclude assessment of enhancement kinetics in breast MRI significantly limiting diagnostic interpretation. This case prompted a group discussion and subsequent modification to the patient breast MRI safety screening questionnaire at our institution.

16.
Kidney Int ; 95(4): 948-957, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30904069

RESUMEN

The relationships between renal blood flow (RBF), tissue oxygenation, and inflammatory injury in atherosclerotic renovascular disease (ARVD) are poorly understood. We sought to correlate RBF and tissue hypoxia with glomerular filtration rate (GFR) in 48 kidneys from patients with ARVD stratified by single kidney iothalamate GFR (sGFR). Oxygenation was assessed by blood oxygenation level dependent magnetic resonance imaging (BOLD MRI), which provides an index for the levels of deoxyhemoglobin within a defined volume of tissue (R2*). sGFR correlated with RBF and with the severity of vascular stenosis as estimated by duplex velocities. Higher cortical R2* and fractional hypoxia and higher levels of renal vein neutrophil-gelatinase-associated-lipocalin (NGAL) and monocyte-chemoattractant protein-1 (MCP-1) were observed at lower GFR, with an abrupt inflection below 20 ml/min. Renal vein MCP-1 levels correlated with cortical R2* and with fractional hypoxia. Correlations between cortical R2* and RBF in the highest sGFR stratum (mean sGFR 51 ± 12 ml/min; R = -0.8) were degraded in the lowest sGFR stratum (mean sGFR 8 ± 3 ml/min; R = -0.1). Changes in fractional hypoxia after furosemide were also absent in the lowest sGFR stratum. These data demonstrate relative stability of renal oxygenation with moderate reductions in RBF and GFR but identify a transition to overt hypoxia and inflammatory cytokine release with severely reduced GFR. Tissue oxygenation and RBF were less correlated in the setting of reduced sGFR, consistent with variable oxygen consumption or a shift to alternative mechanisms of tissue injury. Identifying transitions in tissue oxygenation may facilitate targeted therapy in ARVD.


Asunto(s)
Aterosclerosis/complicaciones , Tasa de Filtración Glomerular , Inflamación/fisiopatología , Riñón/patología , Obstrucción de la Arteria Renal/fisiopatología , Anciano , Anciano de 80 o más Años , Aterosclerosis/fisiopatología , Hipoxia de la Célula , Estudios Transversales , Femenino , Humanos , Inflamación/etiología , Inflamación/patología , Riñón/diagnóstico por imagen , Riñón/fisiopatología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Oxígeno/análisis , Oxígeno/sangre , Consumo de Oxígeno , Obstrucción de la Arteria Renal/etiología , Obstrucción de la Arteria Renal/patología , Circulación Renal
17.
Amyloid ; 25(2): 101-108, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29733684

RESUMEN

OBJECTIVES: Cardiac involvement is a major determinate of mortality in light chain (AL) amyloidosis. Cardiac magnetic resonance imaging (MRI) feature tracking (FT) strain is a new method for measuring myocardial strain. This study retrospectively evaluated the association of MRI FT strain with all-cause mortality in AL amyloidosis. MATERIALS AND METHODS: Seventy-six patients with newly diagnosed AL amyloidosis underwent cardiac MRI. 75 had images suitable for MRI FT strain analysis. MRI delayed enhancement, morphologic and functional evaluation, cardiac biomarker staging and transthoracic echocardiography were also performed. Subjects' charts were reviewed for all-cause mortality. Cox proportional hazards analysis was used to evaluate survival in univariate and multivariate analysis. RESULTS: There were 52 deaths. Median follow-up of surviving patients was 1.7 years. In univariate analysis, global radial (Hazard Ratio (HR) = 0.95, p <.01), circumferential (HR = 1.09, p < .01) and longitudinal (HR = 1.08, p < .01) strain were associated with all-cause mortality. In separate multivariate models, radial (HR = 0.96, p = .02), circumferential (HR = 1.09, p = .03) and longitudinal strain (HR = 1.07, p = .04) remained prognostic when combined with presence of biomarker stage 3. CONCLUSIONS: MRI FT strain is associated with all-cause mortality in patients with AL amyloidosis.


Asunto(s)
Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/patología , Imagen por Resonancia Magnética/métodos , Anciano , Ecocardiografía , Femenino , Humanos , Amiloidosis de Cadenas Ligeras de las Inmunoglobulinas/metabolismo , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos
18.
Magn Reson Med ; 80(4): 1556-1567, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29488251

RESUMEN

PURPOSE: Dixon-based fat suppression has recently gained interest for dynamic contrast-enhanced MRI, but multi-echo techniques require longer scan times and reduce temporal resolution compared to single-echo alternatives without fat suppression. The purpose of this work is to demonstrate accelerated single-echo Dixon imaging with high spatial and temporal resolution. THEORY AND METHODS: Real-valued water and fat images can be obtained from a single measurement if the shared initial phase and that due to ΔB0 are assumed known a priori. An expression for simultaneous sensitivity encoding (SENSE) unfolding and fat-water separation is derived for the general undersampling case, and simplified under the special case of uniform Cartesian undersampling. In vivo experiments were performed in extremities and brain with SENSE acceleration factors of up to R = 8. RESULTS: Single-echo Dixon reconstruction of highly undersampled data was successfully demonstrated. Dynamic contrast-enhanced water and fat images provided high spatial and temporal resolution dynamic images with image update times shorter than previous single-echo Dixon work. CONCLUSION: Time-resolved contrast-enhanced MRI with single-echo Dixon fat suppression shows high image quality, improved vessel delineation, and reduced sensitivity to motion when compared to time-subtraction methods.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Angiografía por Resonancia Magnética/métodos , Tejido Adiposo/diagnóstico por imagen , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Medios de Contraste , Mano/irrigación sanguínea , Mano/diagnóstico por imagen , Humanos , Procesamiento de Señales Asistido por Computador , Agua/química
19.
Can Assoc Radiol J ; 69(1): 78-91, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29458957

RESUMEN

The atrioventricular (AV) groove constitutes the anatomic space separating the atria and ventricles. The AV groove is often difficult to visualize at echocardiography, and suspected lesions can be further assessed with cardiac computed tomography or magnetic resonance imaging. AV groove lesions may originate from within the AV groove or extend into this space from adjacent structures. The differential diagnosis for AV groove lesions is often wide, but a precise diagnosis can sometimes be made. This pictorial essay illustrates the magnetic resonance imaging and computed tomography appearance of common and uncommon AV groove lesions, and attempts to provide a logical framework for differential diagnosis when confronted with a known or suspected lesion at cross-sectional imaging.


Asunto(s)
Neoplasias Cardíacas/diagnóstico por imagen , Ventrículos Cardíacos/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Femenino , Atrios Cardíacos/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad
20.
Magn Reson Med ; 80(1): 231-238, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29194738

RESUMEN

PURPOSE: To implement a reduced field of view (rFOV) technique for cardiac MR elastography (MRE) and to demonstrate the improvement in image quality of both magnitude images and post-processed MRE stiffness maps compared to the conventional full field of view (full-FOV) acquisition. METHODS: With Institutional Review Board approval, 17 healthy volunteers underwent both full-FOV and rFOV cardiac MRE scans using 140-Hz vibrations. Two cardiac radiologists blindly compared the magnitude images and stiffness maps and graded the images based on several image quality attributes using a 5-point ordinal scale. Fisher's combined probability test was performed to assess the overall evaluation. The octahedral shear strain-based signal-to-noise ratio (OSS-SNR) and median stiffness over the left ventricular myocardium were also compared. RESULTS: One volunteer was excluded because of an inconsistent imaging resolution during the exam. In the remaining 16 volunteers (9 males, 7 females), the rFOV scans outperformed the full-FOV scans in terms of subjective image quality and ghosting artifacts in the magnitude images and stiffness maps, as well as the overall preference. The quantitative measurements showed that rFOV had significantly higher OSS-SNR (median: 1.4 [95% confidence interval (CI): 1.2-1.5] vs. 2.1 [95% CI: 1.8-2.4]), P < 0.05) compared to full-FOV. Although no significant change was found in the median myocardial stiffness between the 2 scans, we observed a decrease in the stiffness variation within the myocardium from 2.1 kPa (95% CI: [1.9, 2.3]) to 1.9 kPa (95% CI: [1.7, 2.0]) for full-FOV and rFOV, respectively (P < 0.05) in a subgroup of 7 subjects with ghosting present in the myocardium. CONCLUSION: This pilot volunteer study demonstrated that rFOV cardiac MRE has the capability to reduce ghosting and to improve image quality in both MRE magnitude images and stiffness maps. Magn Reson Med 80:231-238, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.


Asunto(s)
Imagen Eco-Planar/métodos , Diagnóstico por Imagen de Elasticidad/métodos , Corazón/diagnóstico por imagen , Espectroscopía de Resonancia Magnética/métodos , Adulto , Algoritmos , Artefactos , Femenino , Voluntarios Sanos , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Lípidos , Masculino , Miocardio/patología , Fantasmas de Imagen , Proyectos Piloto , Probabilidad , Ondas de Radio , Radiología , Resistencia al Corte , Relación Señal-Ruido , Estrés Mecánico , Adulto Joven
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