Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Clin Radiol ; 71(9): 889-95, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27210245

RESUMEN

AIM: To examine the interpretive performance of digital breast tomosynthesis (DBT) as an adjunct to digital mammography (DM) compared to DM alone in a series of invasive lobular carcinomas (ILCs) and to assess whether DBT can be used to characterise ILC. MATERIALS AND METHODS: A retrospective, multi-reader study was conducted of 83 mammographic examinations of women with 107 newly diagnosed ILCs ascertained at histology. Consenting women underwent both DM and DBT acquisitions. Twelve radiologists, with varying mammography experience, interpreted DM images alone, reporting lesion location, mammographic features, and malignancy probability using the Breast Imaging-Reporting and Data System (BI-RADS) categories 1-5; they then reviewed DBT images in addition to DM, and reported the same parameters. Statistical analyses compared sensitivity, false-positive rates (FPR), and interpretive performance using the receiver operating characteristics (ROC) curve and the area under the curve (AUC), for reading with DM versus DM plus DBT. RESULTS: Multi-reader pooled ROC analysis for DM plus DBT yielded AUC=0.89 (95% confidence interval [CI]: 0.88-0.91), which was significantly higher (p<0.0001) than DM alone with AUC=0.84 (95% CI: 0.82-0.86). DBT plus DM significantly increased pooled sensitivity (85%) compared to DM alone (70%; p<0.0001). FPR did not vary significantly with the addition of DBT to DM. Interpreting with DBT (compared to DM alone) increased the correct identification of ILCs depicted as architectural distortions (84% versus 65%, respectively) or as masses (89% versus 70%), increasing interpretive performance for both experienced and less-experienced readers; larger gains in AUC were shown for less-experienced radiologists. Multifocal and/or multicentric and bilateral disease was more frequently identified on DM with DBT. CONCLUSION: Adding DBT to DM significantly improved the accuracy of mammographic interpretation for ILCs and contributed to characterising disease extent.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Carcinoma Lobular/diagnóstico por imagen , Carcinoma Lobular/patología , Mamografía/métodos , Intensificación de Imagen Radiográfica/métodos , Anciano , Detección Precoz del Cáncer/métodos , Femenino , Humanos , Imagenología Tridimensional/métodos , Persona de Mediana Edad , Imagen Multimodal/métodos , Invasividad Neoplásica , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/métodos
2.
Med Phys ; 39(4): 1704-15, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22482596

RESUMEN

PURPOSE: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a radiological tool for the detection and discrimination of breast lesions. The aim of this study is to evaluate a computer-aided diagnosis (CAD) system for discriminating malignant from benign breast lesions at DCE-MRI by the combined use of morphological, kinetic, and spatiotemporal lesion features. METHODS: Fifty-four malignant and 19 benign breast lesions in 51 patients were retrospectively evaluated. Images were acquired at two centers at 1.5 T. Mass-like lesions were automatically segmented after image normalization and elastic coregistration of contrast-enhanced frames. For each lesion, a set of 28 3D features were extracted: ten morphological (related to shape, margins, and internal enhancement distribution); nine kinetic (computed from signal-to-time curves); and nine spatiotemporal (related to the variation of the signal between adjacent frames). A support vector machine (SVM) was trained with feature subsets selected by a genetic search. Best subsets were composed of the most frequent features selected by majority rule. The performance was measured by receiver operator characteristics analysis with a stratified tenfold cross-validation and bootstrap method for confidence intervals. RESULTS: SVM training by the three separated classes of features resulted in an area under the curve (AUC) of 0.90 ± 0.04 (mean ± standard deviation), 0.87 ± 0.06, and 0.86 ± 0.06 for morphological, kinetic, and spatiotemporal feature, respectively. Combined training with all 28 features resulted in AUC of 0.96 ± 0.02 obtained with a selected feature subset composed by two morphological, one kinetic, and two spatiotemporal features. CONCLUSIONS: Quantitative combination of morphological, kinetic, and spatiotemporal features is feasible and provides a higher discriminating power than using the three different classes of features separately.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Gadolinio DTPA , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Modelos Biológicos , Reconocimiento de Normas Patrones Automatizadas/métodos , Algoritmos , Simulación por Computador , Medios de Contraste , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Máquina de Vectores de Soporte
3.
J Exp Clin Cancer Res ; 21(3 Suppl): 115-24, 2002 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-12585665

RESUMEN

This report presents the preliminary results of the first phase (21 months) of a multi-centre, non-randomised, prospective study, aimed at evaluating the effectiveness of contrast-enhanced magnetic resonance imaging (MRI), X-ray mammography (XM) and ultrasound (US) in early diagnosis of breast cancer (BC) in subjects at high genetic risk. This Italian national trial (coordinated by the Istituto Superiore di Sanità, Rome) so far recruited 105 women (mean age 46.0 years; median age 51.0; age range 25-77 years), who were either proven BRCA1 or BRCA2 mutation carriers or had a 1 in 2 probability of being carriers (40/105 with a previous personal history of BC). Eight cases of breast carcinomas were detected in the trial (mean age 55.3 years, median age 52.5; age range 35-70 years; five with previous personal history of BC). All trial-detected BC cases (8/8) were identified by MRI, while XM and US correctly classified only one. MRI had one false positive case, XM and US none. Seven "MRI-only" detected cancers (4 invasive, 3 in situ) occurred in both pre- (n = 2) and post-menopausal (n = 5) women. With respect to the current XM screening programmes addressed to women in the age range 50-69 years, the global incidence of BC in the trial (7.6%) was over ten-fold higher. The cost per "MRI-only" detected cancer in this particular category of subjects at high genetic risk was substantially lower than that of an XM-detected cancer in the general women population. These preliminary results confirmed that MRI is a very useful tool to screen subjects at high genetic risk for breast carcinoma, not only in pre-, but also in post-menopausal age, with a low probability of false positive cases.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Imagen por Resonancia Magnética , Tamizaje Masivo , Adulto , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Reacciones Falso Positivas , Femenino , Gadolinio , Genes BRCA1 , Genes BRCA2 , Predisposición Genética a la Enfermedad , Humanos , Mamografía , Tamizaje Masivo/economía , Persona de Mediana Edad , Mutación , Estudios Prospectivos , Intensificación de Imagen Radiográfica , Ultrasonografía Mamaria
4.
Comput Methods Programs Biomed ; 117(3): 482-8, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25262335

RESUMEN

BACKGROUND AND OBJECTIVE: Vascularity evaluation on breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has a potential diagnostic value, but it represents a time consuming procedure, affected by intra- and inter-observer variability. This study tests the application of a recently published method to reproducibly quantify breast vascularity, and evaluates if the vascular volume of cancer-bearing breast, calculated from automatic vascular maps (AVMs), may correlate with pathologic tumor response after neoadjuvant chemotherapy (NAC). METHODS: Twenty-four patients with unilateral locally advanced breast cancer underwent DCE-MRI before and after NAC, 8 responders and 16 non-responders. A validated algorithm, based on multiscale 3D Hessian matrix analysis, provided AVMs and allowed the calculation of vessel volume before the initiation and after the last NAC cycle for each breast. For cancer bearing breast, the difference in vascular volume before and after NAC was compared in responders and non-responders using the Wilcoxon two-sample test. A radiologist evaluated the vascularity on the subtracted images (first enhanced minus unenhanced), before and after treatment, assigning a vascular score for each breast, according to the number of vessels with length ≥30mm and maximal transverse diameter ≥2mm. The same evaluation was repeated with the support of the simultaneous visualization of the AVMs. The two evaluations were compared in terms of mean number of vessels and mean vascular score per breast, in responders and non-responders, by use of Wilcoxon two sample test. For all the analysis, the statistical significance level was set at 0.05. RESULTS: For breasts harboring the cancer, evidence of a difference in vascular volume before and after NAC for responders (median=1.71cc) and non-responders (median=0.41cc) was found (p=0.003). A significant difference was also found in the number of vessels (p=0.03) and vascular score (p=0.02) before or after NAC, according to the evaluation supported by the AVMs. CONCLUSIONS: The encouraging, although preliminary, results of this study suggest the use of AVMs as new biomarker to evaluate the pathologic response after NAC, but also support their application in other breast DCE-MRI vessel analysis that are waiting for a reliable quantification method.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Mama/patología , Imagen por Resonancia Magnética/métodos , Adulto , Algoritmos , Biomarcadores/metabolismo , Neoplasias de la Mama/terapia , Quimioterapia Adyuvante/métodos , Medios de Contraste/química , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Mamografía/métodos , Persona de Mediana Edad , Terapia Neoadyuvante/métodos , Reproducibilidad de los Resultados , Ultrasonografía Mamaria/métodos
5.
Eur J Surg Oncol ; 37(3): 199-204, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21237612

RESUMEN

AIMS: The role of magnetic resonance imaging (MRI) in the local staging of breast cancer is currently uncertain. The purpose of this prospective study is to evaluate the accuracy of preoperative MRI compared to conventional imaging in detecting breast cancer and the effect of preoperative MRI on the surgical treatment in a subgroup of women with dense breasts, young age, invasive lobular cancer (ILC) or multiple lesions. METHODS: Between January 2006 and October 2007, 91 patients with newly diagnosed breast cancer underwent preoperative clinical breast examination, mammography, bilateral breast ultrasonography and high-resolution breast MRI. All patients had histologically verified breast cancer. The imaging techniques were compared using the final pathological report as gold standard. RESULTS: The sensitivity of MRI for the main lesion was 98.9%, while for multiple lesions sensitivity was 90.7% and specificity 85.4%. After preoperative MRI, 13 patients (14.3%) underwent additional fine needle/core biopsies, 9 of whom had specimen positive for cancer. Preoperative MRI changed the surgical plan in 26 patients: in 19.8% of the cases breast conservative surgery was converted to mastectomy and in 7.7% of the patients a wider excision was performed. At a mean follow-up of 48 months, 2 local recurrences occurred (local failure rate = 2.5%). CONCLUSIONS: Enhanced sensitivity of breast MRI may change the surgical approach, by increasing mastectomy rate or suggesting the need of wider local excision. MRI can play an important role in preoperative planning if used in selected patients with high risk of multifocal/multicentric lesions. However, the histologic confirmation of all suspicious findings detected by MRI is mandatory prior to definite surgery.


Asunto(s)
Neoplasias de la Mama/patología , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Anciano de 80 o más Años , Biopsia , Neoplasias de la Mama/cirugía , Distribución de Chi-Cuadrado , Medios de Contraste , Femenino , Gadolinio DTPA , Humanos , Interpretación de Imagen Asistida por Computador , Mamografía , Persona de Mediana Edad , Invasividad Neoplásica , Recurrencia Local de Neoplasia , Estadificación de Neoplasias , Estudios Prospectivos , Sensibilidad y Especificidad , Estadísticas no Paramétricas , Ultrasonografía Mamaria
6.
Radiol Med ; 113(8): 1085-95, 2008 Dec.
Artículo en Inglés, Italiano | MEDLINE | ID: mdl-18953635

RESUMEN

The clinical use of breast magnetic resonance (MR) imaging is increasing, especially for applications requiring paramagnetic contrast-agent injection. This document presents a synthetic list of acceptable indications with potential advantages for women according to evidence from the literature and the expert opinion of the panel that developed this statement. We generally recommend that breast MR imaging be performed in centres with experience in conventional breast imaging [mammography and ultrasonography (US)] and needle-biopsy procedures (under stereotactic or US guidance) as well as in breast MR imaging and second-look US for findings not revealed by conventional imaging performed before MR imaging. In our opinion, there is no evidence in favour of breast MR imaging as a diagnostic tool to characterise equivocal findings at conventional imaging when needle-biopsy procedures can be performed, nor for the study of asymptomatic, non-high-risk women with negative conventional imaging. After a description of technical and methodological requirements, we define the indications and limitations of breast MR imaging for surveillance of high-risk women, local staging before surgery, evaluation of the effect of neoadjuvant chemotherapy, breast previously treated for carcinoma, carcinoma of unknown primary syndrome, nipple discharge and breast implants.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Imagen por Resonancia Magnética , Femenino , Humanos
7.
Artículo en Inglés | MEDLINE | ID: mdl-18001887

RESUMEN

DCE-MRI is a diagnostic method that can visualize neoangiogenic-induced vascular changes. Typically, the analysis of these data is time-consuming and the visualization of the quantitative information on tumor vasculature, derivable from DCE-MRI, is not easy and comfortable. In this study, we propose a method to accelerate computation and analysis of DCE-MRI data, while making easy to use the functional information obtained from model-based functional analysis.


Asunto(s)
Neoplasias de la Mama/patología , Imagen de Difusión por Resonancia Magnética/métodos , Interpretación de Imagen Asistida por Computador , Neoplasias de la Mama/irrigación sanguínea , Medios de Contraste , Femenino , Gadolinio DTPA , Humanos , Estadificación de Neoplasias
8.
Acta Radiol ; 45(1): 71-4, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15164782

RESUMEN

PURPOSE: To study the role of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in monitoring the response of bone metastases to endocrine therapy combined with bisphosphonates in patients with breast cancer. MATERIAL AND METHODS: Ten breast cancer patients with bone metastases who were to receive endocrine therapy and bisphosphonates were investigated prospectively by DCE-MRI. We chose a reference lesion for each patient who was studied at baseline, within 3 weeks from the second administration of bisphosphonates, and after 4 and 8 months from the initiation of medical treatment. Time/intensity curves, representing temporal changes of signal intensity in areas of interest in the context of the target lesions (ROI), were obtained for each DCE-MRI. RESULTS: Changes in the shape of the T/I curves suggesting tumor regression were seen shortly after the initiation of medical treatment in the three patients who had the most durable responses. CONCLUSION: DCE-MRI has the potential to detect early changes related to medical treatment in bone metastases from breast cancer. If confirmed in larger series, these data identify DCE-MRI as a diagnostic tool for evaluating new bone targeting antineoplastic agents.


Asunto(s)
Neoplasias Óseas/patología , Neoplasias Óseas/secundario , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Difosfonatos/uso terapéutico , Imagen por Resonancia Magnética , Adulto , Anciano , Anastrozol , Femenino , Goserelina/uso terapéutico , Humanos , Imidazoles/uso terapéutico , Letrozol , Persona de Mediana Edad , Nitrilos/uso terapéutico , Pamidronato , Proyectos Piloto , Estudios Prospectivos , Tamoxifeno/uso terapéutico , Triazoles/uso terapéutico , Ácido Zoledrónico
9.
Radiol Med ; 99(6): 449-55, 2000 Jun.
Artículo en Italiano | MEDLINE | ID: mdl-11262822

RESUMEN

INTRODUCTION: Aim of this study was to evaluate the sensitivity of virtual colonoscopy (CT colonography) in the identification of colorectal cancer and to define the limitations and the advantages of this imaging modality, as well as indications to the examination. MATERIAL AND METHODS: We examined prospectively 62 symptomatic patients aged 36 to 82 years (28 women and 34 men). All patients underwent both conventional and virtual colonoscopy on the same day; the conventional examination allowed exploration of the entire colon. RESULTS: Conventional colonoscopy identified 89 lesions 3-50 mm in diameter, namely 84 benign and 5 malignant lesions. No lesions were identified in 12 patients. CT colonography identified 52 of the 89 lesions, with 57.1% diagnostic accuracy. There were 11 false positives (82.5% positive predictive value and 52.2% specificity) and 37 false negatives (24.5% negative predictive value and 58.4% sensitivity). Sensitivity was significantly higher (85.7%) for polyps > or = 1 cm. CONCLUSIONS: Virtual colonoscopy is an imaging modality with good diagnostic yield, well tolerated by patients and with great potentials for further development. We suggest that the examination be performed in symptomatic patients who cannot undergo total colonoscopy or refuse the other imaging modalities. Further studies are warranted in larger series of patients, possibly introducing it in screening programs.


Asunto(s)
Colonoscopía/métodos , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/patología , Tomografía Computarizada por Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Interfaz Usuario-Computador
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda