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1.
Eur Radiol ; 33(3): 1918-1927, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36305900

RESUMEN

OBJECTIVES: To develop a CT-based algorithm and evaluate its performance for the diagnosis of blunt bowel and/or mesenteric injury (BBMI) in patients with blunt abdominal trauma. METHODS: This retrospective study included a training cohort of 79 patients (29 with BBMI and 50 patients with blunt abdominal trauma without BBMI) and a validation cohort of 37 patients (13 patients with BBMI and 24 patients with blunt abdominal trauma without BBMI). CT examinations were blindly analyzed by two independent radiologists. For each CT sign, the kappa value, sensitivity, specificity, and accuracy were calculated. A diagnostic algorithm was built using a recursive partitioning model on the training cohort, and its performances were assessed on the validation cohort. RESULTS: CT signs with kappa value > 0.6 were extraluminal gas, hemoperitoneum, no or moderate bowel wall enhancement, and solid organ injury. CT signs yielding best accuracies in the training cohort were extraluminal gas (98%; 95% CI: 91-100), bowel wall defect (97%; 95% CI: 91-100), irregularity of mesenteric vessels (97%; 95% CI: 90-99), and mesenteric vessel extravasation (97%; 95% CI: 90-99). Using a recursive partitioning model, a decision tree algorithm including extraluminal gas and no/moderate bowel wall enhancement was built, achieving 86% sensitivity (95% CI: 74-99) and 96% specificity (95% CI: 91-100) in the training cohort and 92% sensitivity (95% CI: 78-97) and 88% specificity (95% CI: 74-100) in the validation cohort for the diagnosis of BBMI. CONCLUSIONS: An effective diagnostic algorithm was built to identify BBMI in patients with blunt abdominal trauma using only extraluminal gas and no/moderate bowel wall enhancement on CT examination. KEY POINTS: • A CT diagnostic algorithm that included extraluminal gas and no/moderate bowel wall enhancement was built for the diagnosis of surgical blunt bowel and/or mesenteric injury. • A decision tree combining only two reproducible CT signs has high diagnostic performance for the diagnosis of surgical blunt bowel and/or mesenteric injury.


Asunto(s)
Traumatismos Abdominales , Heridas no Penetrantes , Humanos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Intestinos/lesiones , Heridas no Penetrantes/diagnóstico por imagen , Traumatismos Abdominales/diagnóstico por imagen , Mesenterio/lesiones , Algoritmos
2.
J Magn Reson Imaging ; 50(5): 1514-1525, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-30989761

RESUMEN

BACKGROUND: Although several studies have evaluated dynamic contrast-enhanced (DCE) MRI in the orbit, showing its utility when detecting and diagnosing orbital lesions, none have evaluated the pharmacokinetic models. PURPOSE: To provide a quality-based pharmacokinetic model selection for characterizing orbital lesions using DCE-MRI at 3.0T. STUDY TYPE: Prospective. POPULATION: From December 2015 to April 2017, 151 patients with an orbital lesion underwent MRI prior to surgery, including a high temporal resolution DCE sequence, divided into one training and one test dataset with 100 and 51 patients, respectively. FIELD STRENGTH/SEQUENCE: 3T/DCE. ASSESSMENT: Six different pharmacokinetic models were tested. STATISTICAL TESTS: Univariate and multivariate analyses were performed using Wilcoxon-2-sample tests and a logistic regression to compare parameters between malignant and benign tumors for each pharmacokinetic model for the whole cohort. Receiver operating characteristic (ROC) curve analyses were performed on the training dataset to determine area under curve (AUC) and optimal cutoff values for each pharmacokinetic model, then validated on the test dataset to calculate sensitivity, specificity, and accuracy. RESULTS: Regardless of the model, tissue blood flow and tissue blood volume values were significantly higher in malignant vs. benign lesions: 103.8-195.1 vs. 65-113.8, P [<10-4 -2.10-4 ] and 21.3-36.9 vs. 15.6-33.6, P [<10-4 -0.03] respectively. Extracellular volume fraction and permeability-surface area product or transfer constant appeared to be less relevant: 17.3-27.5 vs. 22.8-28.2, P [0.01-0.7], 1.7-4.9, P [0.2-0.9] and 9.5-38.8 vs. 8.1-22.8, P [<10-4 -0.6], respectively. ROC curves showed no significant differences in AUC between the different models. The two-compartment exchange (2CX) model ranked first for quality. DATA CONCLUSION: DCE MRI pharmacokinetic model-derived parameters appeared to be useful for discriminating benign from malignant orbital lesions. The 2CX model provided the best quality of modeling and should be recommended. Perfusion-related DCE parameters appeared to be significantly more relevant to the diagnostic process. Level of Evidence 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1514-1525.


Asunto(s)
Medios de Contraste/farmacología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética , Neoplasias Orbitales/diagnóstico por imagen , Adulto , Algoritmos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Perfusión , Permeabilidad , Estudios Prospectivos , Garantía de la Calidad de Atención de Salud , Curva ROC , Reproducibilidad de los Resultados
3.
Fetal Diagn Ther ; 44(4): 277-284, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29689556

RESUMEN

PURPOSE: To evaluate placental function and perfusion in a rat model of preeclampsia infused with L-nitro-arginine methyl ester (L-NAME) by dynamic contrast-enhanced (DCE) MRI using gadolinium chelates. METHODS: Pregnant female Sprague-Dawley rats were fitted on embryonic day 16 (E16) with subcutaneous osmotic minipumps loaded to deliver, continuously, L-NAME (50 mg/day per rat; case group) or saline solution (control group). DCE MRI was performed on E19 using gadolinium chelates and a 4.7-T MRI apparatus for small animals. Quantitative analysis was performed using an image software program: placental blood flow (perfusion in mL/min/100 mL of placenta) and fractional volume of the maternal vascular placental compartment (ratio between the placental blood volume and the placental volume, Vb in %) were calculated by compartmental analysis. RESULTS: A total of 176 placentas (27 rats) were analyzed by DCE MRI (97 cases and 79 controls). The model was effective, inducing intrauterine growth retardation, as there was a significant difference between the two groups for placental weight (p < 0.01), fetal weight (p = 0.019), and fetal length (p < 0.01). There was no significant difference in placental perfusion between the L-NAME and control groups (140.1 ± 74.1 vs. 148.9 ± 97.4, respectively; p = 0.496). There was a significant difference between the L-NAME and control groups for Vb (53 ± 12.9 vs. 46.7 ± 9%, respectively; p < 0.01). CONCLUSION: In the L-NAME preeclampsia model, placental perfusion is normal and the fractional blood volume is increased, suggesting that preeclampsia is not always expressed as a result of decreased placental perfusion. This highlights the usefulness of MRI for investigating the physiopathology of preeclampsia.


Asunto(s)
Placenta/fisiopatología , Preeclampsia/fisiopatología , Animales , Volumen Sanguíneo , Femenino , Imagen por Resonancia Magnética , Placenta/irrigación sanguínea , Embarazo , Ratas , Ratas Sprague-Dawley , Flujo Sanguíneo Regional
4.
J Magn Reson Imaging ; 46(6): 1776-1785, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28370815

RESUMEN

PURPOSE: To evaluate the value of quantifying dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) heterogeneity to characterize adnexal masses. MATERIALS AND METHODS: Our database was retrospectively queried to identify all surgically proven adnexal masses characterized with a 1.5T DCE-MRI between January 1st 2008 and February 28th 2010 (n = 113 masses, including 52 benign, 11 borderline, and 50 invasive malignant tumors). The solid component of the adnexal mass was segmented. Quantitative analysis with a compartmental model was performed to calculate microvascular parameters, including tissue blood flow (FT ), blood volume fraction (Vb ), lag time (DAT ), interstitial volume fraction (Ve ), permeability-surface area product (PS), and relative area under curve (r AUC), were calculated. Then heterogeneity parameters were evaluated using the analysis of the evolution of the standard deviation (SD) of signal intensities on DCE-MRI series. The area under the receiver operating characteristic (AUROC) curve was calculated to assess the overall discrimination of parameters. RESULTS: Malignant tumors displayed higher FT , Vb , and r AUC and lower DAT than benign tumors (P = 0.01, P < 0.0001, and P < 0.0001, respectively). Invasive malignant tumors displayed lower Vb and r AUC than borderline tumors (P < 0.01). After injection, whenever the heterogeneity parameter was considered, malignant tumors were more heterogeneous than benign tumors, invasive tumors were more heterogeneous than borderline ovarian tumors, and malignant tumors with carcinomatosis were more heterogeneous than tumors without carcinomatosis (P < 0.001). The most discriminant parameter was the SD during the 90 seconds after injection related to arterial input function (ΔSDEARLY/AIF ) with an AUROC between 0.715 and 0.808. CONCLUSION: This study proposes heterogeneity parameters as a new tool with a potential for clinical application, given that the technique uses routine imaging sequences. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1776-1785.


Asunto(s)
Enfermedades de los Anexos/diagnóstico por imagen , Medios de Contraste , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Neoplasias Ováricas/irrigación sanguínea , Neoplasias Ováricas/diagnóstico por imagen , Anexos Uterinos/irrigación sanguínea , Anexos Uterinos/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Diferencial , Femenino , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Adulto Joven
5.
Radiology ; 277(3): 773-83, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26131910

RESUMEN

PURPOSE: To correlate intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters with the enhancement patterns of bone marrow and focal lesion obtained on whole-body (WB) dynamic contrast agent-enhanced (DCE) magnetic resonance (MR) images in patients with stage-III multiple myeloma (MM) before and after systemic therapy. MATERIALS AND METHODS: Twenty-seven patients with MM were retrospectively included in this institutional review board-approved study. Requirement for written informed consent was waived. All patients underwent WB DCE MR imaging before treatment and 18 patients underwent repeat MR imaging 3 months after treatment. A transverse IVIM DWI sequence with 10 b values (0, 10, 20, 30, 50, 80, 100, 200, 400, and 800 sec/mm(2)) was acquired within bone marrow and focal lesions. The IVIM parameters (perfusion fraction [f], molecular diffusion coefficient [D], and perfusion-related D [D*]) and apparent diffusion coefficient (ADC) were extracted for both focal lesions and bone marrow and correlated with focal lesions and maximal bone marrow enhancement (BMEmax) (Spearman correlation coefficient) at baseline and at follow-up (Wilcoxon signed-rank test). RESULTS: D and ADC values positively correlated with BMEmax (r = 0.7, P < .001; and r = 0.455, P = .0435, respectively). Patients with increased BMEmax showed significantly increased ADC and D within bone marrow versus patients who did not have increased BMEmax (ADC, 0.67 × 10(-3) mm(2)/sec vs 0.54 × 10(-3) mm(2)/sec, P = .03; D, 0.58 × 10(-3) mm(2)/sec vs 0.42 × 10(-3) mm(2)/sec, P < .001). Within focal lesions, f was the maximum in lesions that showed enhancement followed by washout. After treatment in good responders, the significant decrease in maximal enhancement value of focal lesions (baseline vs after treatment, 213.9% ± 78.7 [standard deviation] vs 131% ± 53.6, respectively; P < .001) was accompanied by a significant decrease in f (baseline vs after treatment, 11% ± 3.8 vs 5.8% ± 4.7, respectively; P < .001). CONCLUSION: Diffuse bone marrow involvement is associated with increased D. Hypervascular focal lesions with high maximal enhancement value of focal lesions also show high f value. Likewise, the decreased maximal enhancement value of focal lesions after treatment is accompanied by decreased f.


Asunto(s)
Imagen de Difusión por Resonancia Magnética/métodos , Mieloma Múltiple/diagnóstico , Adulto , Anciano , Médula Ósea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mieloma Múltiple/terapia , Variaciones Dependientes del Observador , Estudios Retrospectivos
7.
Radiology ; 273(3): 801-12, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25102294

RESUMEN

PURPOSE: To evaluate if measurement of split renal function ( SRF split renal function ) with dynamic contrast material-enhanced ( DCE dynamic contrast enhanced ) magnetic resonance (MR) urography is equivalent to that with renal scintigraphy ( RS renal scintigraphy ) in patients suspected of having chronic urinary obstruction. MATERIALS AND METHODS: The study protocol was approved by the institutional ethics committee of the coordinating center on behalf of all participating centers. Informed consent was obtained from all adult patients or both parents of children. This prospective, comparative study included 369 pediatric and adult patients from 14 university hospitals who were suspected of having chronic or intermittent urinary obstruction, and data from 295 patients with complete data were used for analysis. SRF split renal function was measured by using the area under the curve and the Patlak-Rutland methods, including successive review by a senior and an expert reviewer and measurement of intra- and interobserver agreement for each technique. An equivalence test for mean SRF split renal function was conducted with an α of 5%. RESULTS: Reproducibility was substantial to almost perfect for both methods. Equivalence of DCE dynamic contrast enhanced MR urography and RS renal scintigraphy for measurement of SRF split renal function was shown in patients with moderately dilated kidneys (P < .001 with the Patlak-Rutland method). However, in severely dilated kidneys, the mean SRF split renal function measurement was underestimated by 4% when DCE dynamic contrast enhanced MR urography was used compared with that when RS renal scintigraphy was used. Age and type of MR imaging device had no significant effect. CONCLUSION: For moderately dilated kidneys, equivalence of DCE dynamic contrast enhanced MR urography to RS renal scintigraphy was shown, with a standard deviation of approximately 12% between the techniques, making substitution of DCE dynamic contrast enhanced MR urography for RS renal scintigraphy acceptable. For severely dilated kidneys, a mean underestimation of SRF split renal function of 4% should be expected with DCE dynamic contrast enhanced MR urography, making substitution questionable.


Asunto(s)
Hidronefrosis/diagnóstico , Imagen por Resonancia Magnética/métodos , Obstrucción Uretral/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Enfermedad Crónica , Medios de Contraste , Femenino , Hospitales Universitarios , Humanos , Hidronefrosis/etiología , Imagenología Tridimensional , Lactante , Recién Nacido , Síntomas del Sistema Urinario Inferior/diagnóstico , Masculino , Persona de Mediana Edad , Radiofármacos , Reproducibilidad de los Resultados , Obstrucción Uretral/etiología
8.
Urol Int ; 92(2): 250-2, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24457980

RESUMEN

We report on a 32-year-old man with a history of chronic lower abdominal pain and urogenital symptoms, leading to the diagnosis of coloseminal fistula complicating diverticular disease. We reviewed the literature on this rare clinical entity and would like to stress the role of pelvic imaging with rectal contrast to investigate complicated forms of diverticular disease.


Asunto(s)
Colon Sigmoide/patología , Colon Sigmoide/cirugía , Diverticulitis/complicaciones , Diverticulitis/cirugía , Fístula/complicaciones , Fístula/cirugía , Adulto , Medios de Contraste/química , Humanos , Litotricia , Masculino , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Vejiga Urinaria/diagnóstico por imagen
9.
Radiology ; 269(1): 277-82, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23687173

RESUMEN

PURPOSE: To demonstrate that strandlike hypointense signals seen in the myocardium of normal rat hearts correspond to myocardial microvessels with high-spatial-resolution susceptibility-weighted (SW) magnetic resonance (MR) imaging without injection of contrast medium. MATERIALS AND METHODS: Animal experiments were performed with institutional animal care committee approval. Ex vivo cardiac MR imaging was performed in 10 normal Wistar rats with a 4.7-T imager and a cryogenic probe. The hypothesis that thin tubular hypointense signals in the myocardium of rat hearts at SW MR imaging sequences (group 1, n = 6; in-plane resolution, 39 µm) represent intramyocardial microvessels was tested. A superparamagnetic intravascular contrast agent (ferumoxsil; Lumirem) was used to explore the distribution of the intramyocardial microvessels (group 2, n = 4; three-dimensional fast imaging with steady-state free precession sequences). Nonparametric Mann-Whitney tests were performed to compare groups 1 and 2 both for microvascular densities (MVD) on histologic sections and for MR imaging signal intensities (SIs). Wilcoxon signed rank tests were used for paired comparison of subepicardial and subendocardial MVD and SI within groups. RESULTS: Ferumoxsil opacified the coronary microvasculature (group 2) on MR-matched histologic sections. No statistically significant difference was found between groups 1 and 2 for either MVD or MR imaging SI expressed as ratios between subendocardium and subepicardium (P = .40 and P = .46, respectively). The comparison of mean subendocardial and subepicardial SI within groups revealed significantly more microvessels in the subepicardium with MR (group 1: P = .01; group 2: P = .004). CONCLUSION: Myocardial microvessels appear as strandlike structures on high-spatial-resolution SW MR images without the aid of contrast medium injection.


Asunto(s)
Algoritmos , Vasos Coronarios/anatomía & histología , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Angiografía por Resonancia Magnética/métodos , Microvasos/anatomía & histología , Animales , Femenino , Microcirculación , Ratas , Ratas Wistar , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
10.
Rev Prat ; 63(4): 529-34, 2013 Apr.
Artículo en Francés | MEDLINE | ID: mdl-23682485

RESUMEN

Since the development of the new imaging techniques, such as ultrasonography and computed tomography, the attitude over acute appendicitis syndrome has drastically evolved, and the rate of negative appendectomies has noticeably decreased. These techniques allow, not only to improve the performance of the diagnosis of appendicitis, but also to assess the severity and the complications prior to surgery. Furthermore they are useful for establishing alternative diagnoses of the many diseases that may mimic acute appendicitis.


Asunto(s)
Apendicitis/diagnóstico , Adulto , Diagnóstico Diferencial , Diagnóstico por Imagen , Humanos
11.
Radiology ; 258(2): 435-45, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21177386

RESUMEN

PURPOSE: To develop a new automated filtering technique and to evaluate its ability to compensate for the known low contrast-to-noise ratio (CNR) in dynamic contrast material-enhanced (DCE) magnetic resonance (MR) and computed tomographic (CT) data, without substantial loss of information. MATERIALS AND METHODS: Clinical data acquisition for this study was approved by the institutional review board. Principal component analysis (PCA) was combined with the fraction of residual information (FRI) criterion to optimize the balance between noise reduction efficiency and information conservation. The PCA FRI filter was evaluated in 15 DCE MR imaging data sets and 15 DCE CT data sets by two radiologists who performed visual analysis and quantitative assessment of noise reduction after filtering. RESULTS: Visual evaluation revealed a substantial noise reduction while conserving information in 90% of MR imaging cases and 87% of CT cases for image analysis and in 93% of MR imaging cases and 90% of CT cases for signal analysis. Efficient denoising enabled improvement in structure characterization in 60% of MR imaging cases and 77% of CT cases. After filtering, CNR was improved by 2.06 ± 0.89 for MR imaging (P < .01) and by 5.72 ± 4.82 for CT (P < .01). CONCLUSION: This PCA FRI filter demonstrates noise reduction efficiency and information conservation for both DCE MR data and DCE CT data. FRI analysis enabled automated optimization of the parameters for the PCA filter and provided an optional visual control of residual information losses. The robust and fast PCA FRI filter may improve qualitative or quantitative analysis of DCE imaging in a clinical context. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.10100231/-/DC1.


Asunto(s)
Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X/métodos , Medios de Contraste/administración & dosificación , Humanos , Meglumina/administración & dosificación , Neoplasias/diagnóstico , Neoplasias/diagnóstico por imagen , Compuestos Organometálicos/administración & dosificación , Análisis de Componente Principal , Estadísticas no Paramétricas
12.
BMC Cancer ; 11: 361, 2011 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-21854572

RESUMEN

BACKGROUND: To illustrate that Breast-MRI performed in high spatial resolution and low temporal resolution (1 minute) allows the measurement of kinetic parameters that can assess the final pathologic response to neoadjuvant chemotherapy in breast cancer. METHODS: Breast-MRI was performed in 24 women before and after treatment. Eight series of 1.11 minute-duration were acquired with a sub-millimeter spatial resolution. Transfer constant (K(trans)) and leakage space (V(e)) were calculated using measured and theoretical Arterial Input Function (AIF). Changes in kinetic parameters after treatment obtained with both AIFs were compared with final pathologic response graded in non-responder (< 50% therapeutic effect), partial-responder (> 50% therapeutic effect) and complete responder. Accuracies to identify non-responders were compared with receiver operating characteristic curves. RESULTS: With measured-AIF, changes in kinetic parameters measured after treatment were in agreement with the final pathological response. Changes in V(e) and K(trans) were significantly different between non-(N = 11), partial-(N = 7), and complete (N = 6) responders, (P = 0.0092 and P = 0.0398 respectively). A decrease in V(e) of more than -72% and more than -84% for K(trans) resulted in 73% sensitivity for identifying non-responders (specificity 92% and 77% respectively). A decrease in V(e) of more than -87% helped to identify complete responders (Sensitivity 89%, Specificity 83%). With theoretical-AIF, changes in kinetic parameters had lower accuracy. CONCLUSION: There is a good agreement between pathological findings and changes in kinetic parameters obtained with breast-MRI in high spatial and low temporal resolution when measured-AIF is used. Further studies are necessary to confirm whether MRI contrast kinetic parameters can be used earlier as a response predictor to neoadjuvant chemotherapy.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Angiografía por Resonancia Magnética/métodos , Adulto , Neoplasias de la Mama/irrigación sanguínea , Femenino , Humanos , Angiografía por Resonancia Magnética/normas , Microcirculación , Persona de Mediana Edad , Terapia Neoadyuvante , Clasificación del Tumor , Curva ROC , Flujo Sanguíneo Regional , Estudios Retrospectivos , Estadísticas no Paramétricas
13.
Magn Reson Imaging ; 80: 39-49, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33905829

RESUMEN

Dynamic-Contrast-Enhanced (DCE) Imaging has been widely studied to characterize microcirculatory disorders associated with various diseases. Although numerous studies have demonstrated its diagnostic interest, the physiological interpretation using pharmacokinetic models often remains debatable. Indeed, to be interpretable, a model must provide, at first instance, an accurate description of the DCE data. However, the evaluation and optimization of this accuracy remain rather limited in DCE. Here we established a non-linear Free-Time-Point-Hermite (FTPH) data-description model designed to fit DCE data accurately. Its performance was evaluated on data generated using two contrasting pharmacokinetic microcirculatory hypotheses (MH). The accuracy of data description of the models was evaluated by calculating the mean squared error (QE) from initial and assessed tissue impulse responses. Then, FTPH assessments were provided to blinded observers to evaluate if these assessments allowed observers to identify MH in their data. Regardless of the initial pharmacokinetic model used for data generation, QE was lower than 3% for the noise-free datasets and increased up to 10% for a signal-to-noise-ratio (SNR) of 20. Under SNR = 20, the sensitivity and specificity of the MH identification were over 80%. The performance of the FTPH model was higher than that of the B-Spline model used as a reference. The accuracy of the FTPH model regardless of the initial MH provided an opportunity to have a reference to check the accuracy of other pharmacokinetic models.


Asunto(s)
Medios de Contraste , Imagen por Resonancia Magnética , Humanos , Microcirculación , Sensibilidad y Especificidad , Relación Señal-Ruido
15.
Therap Adv Gastroenterol ; 13: 1756284820934314, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32774463

RESUMEN

BACKGROUND AND AIMS: The role of small bowel neoplasia (SBN) screening in asymptomatic patients with Lynch syndrome (LS) is uncertain. The aim of our study was to assess the effectiveness of screening by capsule endoscopy (CE) in these patients. METHODS: This study was an observational, analytical, and retrospective single-center study within the PRED-IdF network. All consecutive asymptomatic patients older than 35 years-old with confirmed LS and no personal history of SBN who started the screening from 2010-2015 were included. The baseline screening and 24 months follow-up were performed by CE. The CE diagnostic yield (positive tumor or polyp) and accuracy, using the follow-up as gold standard, were evaluated. RESULTS: A total of 150 patients underwent the SBN screening program and 135 (52.7 ± 11.2 years-old, 37.8% male) met the inclusion criteria. The baseline CE diagnostic yield was 4.4% (3 polyps, 3 tumors) and the proximal small bowel was the most common location (n = 4, 66.7%). In total, 87 patients underwent follow-up and the diagnostic yield was 4.6%.Four patients were considered positive at follow-up (2 adenomas, 2 adenocarcinomas). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CE were 60%, 100%, 100%, 96.9%, and 97%, respectively. CONCLUSIONS: CE is an accurate procedure for baseline screening of SBN in LS patients and may be efficient for follow-up procedures. However, the optimal starting age of screening and intervals of follow-up must be clarified.

16.
Med Image Anal ; 51: 125-143, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30419490

RESUMEN

Dynamical contrast enhanced (DCE) imaging allows non invasive access to tissue micro-vascularization. It appears as a promising tool to build imaging biomarkers for diagnostic, prognosis or anti-angiogenesis treatment monitoring of cancer. However, quantitative analysis of DCE image sequences suffers from low signal to noise ratio (SNR). SNR may be improved by averaging functional information in a large region of interest when it is functionally homogeneous. We propose a novel method for automatic segmentation of DCE image sequences into functionally homogeneous regions, called DCE-HiSET. Using an observation model which depends on one parameter a and is justified a posteriori, DCE-HiSET is a hierarchical clustering algorithm. It uses the p-value of a multiple equivalence test as dissimilarity measure and consists of two steps. The first exploits the spatial neighborhood structure to reduce complexity and takes advantage of the regularity of anatomical features, while the second recovers (spatially) disconnected homogeneous structures at a larger (global) scale. Given a minimal expected homogeneity discrepancy for the multiple equivalence test, both steps stop automatically by controlling the Type I error. This provides an adaptive choice for the number of clusters. Assuming that the DCE image sequence is functionally piecewise constant with signals on each piece sufficiently separated, we prove that DCE-HiSET will retrieve the exact partition with high probability as soon as the number of images in the sequence is large enough. The minimal expected homogeneity discrepancy appears as the tuning parameter controlling the size of the segmentation. DCE-HiSET has been implemented in C++ for 2D and 3D image sequences with competitive speed.


Asunto(s)
Medios de Contraste , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Algoritmos , Humanos , Modelos Estadísticos , Relación Señal-Ruido
17.
Placenta ; 77: 39-45, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30827354

RESUMEN

INTRODUCTION: Non-invasive assessment of placental perfusion is of great interest to characterize placental function in clinical practice. This article proposes a strictly non-invasive MRI technique using ASL to quantify placental blood flow in vivo. The aim of this study was to develop a fMRI tool to quantify placental blood flow (PBF) in rat, by using arterial spin labeling (ASL) MRI at 4.7 T. MATERIALS AND METHODS: MRI was performed with a dedicated magnet for small animals, in pregnant rats on day 20 of the 22-day gestation period. A Look-Locker flow-sensitive alternating inversion recovery gradient echo sequence was developed as ASL technique (TE: 1.55 ms; TR: 3.5 ms, TI: 56 ms, deltaTI: 56 ms, FA: 20°, Matrix: 128 × 128, 8 segments, 4 Nex). Labeling was performed with global and slice-selective inversions, and T1 map was obtained for each mode of inversion. PBF was then derived from a compartmental model of the variation of T1 between global and slice-selective inversions. RESULTS: The full protocol was completed and ASL image post-processing was successful in 18 rats. Forty-seven placentas were analyzed, with a mean PBF of 147 ±â€¯70 ml/min/100 g of placenta, consistent with published values of placental perfusion using invasive techniques. CONCLUSION: ASL MRI is feasible for the quantification of PBF in rats at 4.7 T. This technique, which requires no administration of contrast media, could have implications for non-invasive longitudinal and in vivo animal studies and may be useful for the management of human pregnancies.


Asunto(s)
Angiografía por Resonancia Magnética/métodos , Placenta/irrigación sanguínea , Placenta/diagnóstico por imagen , Circulación Placentaria/fisiología , Animales , Femenino , Interpretación de Imagen Asistida por Computador , Modelos Animales , Embarazo , Ratas , Ratas Sprague-Dawley , Marcadores de Spin
19.
Ann Coloproctol ; 34(3): 152-156, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29991204

RESUMEN

PURPOSE: Primary anal actinomycosis of cryptoglandular origin, a rare cause of anal suppurative disease, requires specific management to be cured. The aims of this retrospective study were to describe clinical, morphological, and microbiological features of this entity and to evaluate management practices for new cases observed since 2001. METHODS: This was a retrospective case series conducted at the Diaconesses-Croix Saint-Simon Hospital in Paris. RESULTS: From January 2001 to July 2016, 7 patients, 6 males and 1 female (median, 49 years), presenting with an actinomycotic abscess with a cryptoglandular anal fistula were included for study. The main symptom was an acute painful ischioanal abscess. One patient exhibited macroscopic small yellow granules ("sulfur granules"), another "watery pus" and a third subcutaneous gluteal septic metastasis. All patients were overweight (body mass index ≥ 25 kg/m2). Histological study of surgically excised tissue established the diagnosis. All the patients were managed with a combination of classical surgical treatment and prolonged antibiotic therapy. No recurrence was observed during follow-up, the median follow-up being 3 years. CONCLUSION: Actinomycosis should be suspected particularly when sulfur granules are present in the pus, patients have undergone multiple surgeries or suppuration has an unusual aspect. Careful histological examination and appropriate cultures of pus are needed to achieve complete eradication of this rare, but easily curable, disease.

20.
Obes Surg ; 28(12): 3910-3915, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30074143

RESUMEN

BACKGROUND AND STUDY AIMS: Post-laparoscopic sleeve gastrectomy (LSG) fistula is a major complication, responsible for high morbidity. Endoscopic treatment represents an alternative to surgical management, with variable approaches and success rates. In this study, we aimed to evaluate the efficacy of endoscopic treatment in a tertiary care center. PATIENTS AND METHODS: Between March 2010 and March 2015, all patients referred to our center for endoscopic treatment of fistula related to laparoscopic sleeve gastrectomy were included. The primary endpoint was defined as a complete closure of the fistula without recurrence within the 2 months. RESULTS: A total of 26 patients were retrospectively included (73% female). The mean time between fistula diagnosis and first endoscopy was 27.4 days (± 22). Twenty-three (88.4%) patients had a complete fistula closure after endoscopic treatment. The healing delay was 76.4 days (± 42.8), and an average of 3.5 (± 1.4) endoscopic procedures were required. Clinical efficacy was 100% when the endoscopic treatment was performed within the first 3 weeks, or 70% afterwards (p = 0.046). The fistula closure rate was similar between patients with endoscopic drainage (with or without other endoscopic techniques) and patient with closing techniques alone (85.7% vs. 89.5%, respectively). CONCLUSION: Endoscopic treatment of fistula after LSG is efficient but requires early procedures within the first 3 weeks. Endoscopic strategies involving closing procedure or drainage procedure seem to be similar, but these data must be confirmed in large prospective clinical studies.


Asunto(s)
Fístula del Sistema Digestivo/cirugía , Endoscopía , Gastrectomía/efectos adversos , Obesidad Mórbida/cirugía , Complicaciones Posoperatorias/cirugía , Adulto , Fístula del Sistema Digestivo/etiología , Drenaje , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Centros de Atención Terciaria , Resultado del Tratamiento
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