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1.
Biomedicines ; 11(6)2023 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-37371626

RESUMEN

PURPOSE: The existing tools to quantify lung function in interstitial lung diseases have significant limitations. Lung MRI imaging using inhaled hyperpolarized xenon-129 gas (129Xe) as a contrast agent is a new technology for measuring regional lung physiology. We sought to assess the utility of the 129Xe MRI in detecting impaired lung physiology in usual interstitial pneumonia (UIP). MATERIALS AND METHODS: After institutional review board approval and informed consent and in compliance with HIPAA regulations, we performed chest CT, pulmonary function tests (PFTs), and 129Xe MRI in 10 UIP subjects and 10 healthy controls. RESULTS: The 129Xe MRI detected highly heterogeneous abnormalities within individual UIP subjects as compared to controls. Subjects with UIP had markedly impaired ventilation (ventilation defect fraction: UIP: 30 ± 9%; healthy: 21 ± 9%; p = 0.026), a greater amount of 129Xe dissolved in the lung interstitium (tissue-to-gas ratio: UIP: 1.45 ± 0.35%; healthy: 1.10 ± 0.17%; p = 0.014), and impaired 129Xe diffusion into the blood (RBC-to-tissue ratio: UIP: 0.20 ± 0.06; healthy: 0.28 ± 0.05; p = 0.004). Most MRI variables had no correlation with the CT and PFT measurements. The elevated level of 129Xe dissolved in the lung interstitium, in particular, was detectable even in subjects with normal or mildly impaired PFTs, suggesting that this measurement may represent a new method for detecting early fibrosis. CONCLUSION: The hyperpolarized 129Xe MRI was highly sensitive to regional functional changes in subjects with UIP and may represent a new tool for understanding the pathophysiology, monitoring the progression, and assessing the effectiveness of treatment in UIP.

2.
Radiology ; 307(5): e221608, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37158720

RESUMEN

Background Traumatic brain injury (TBI) is the leading cause of disability in young adults. Recurrent TBI is associated with a range of neurologic sequelae, but the contributing factors behind the development of such chronic encephalopathy are poorly understood. Purpose To quantify early amyloid ß deposition in the brain of otherwise healthy adult men exposed to repeated subconcussive blast injury using amyloid PET. Materials and Methods In this prospective study from January 2020 to December 2021, military instructors who were routinely exposed to repeated blast events were evaluated at two different points: baseline (before blast exposure from breacher or grenade) and approximately 5 months after baseline (after blast exposure). Age-matched healthy control participants not exposed to blasts and without a history of brain injury were evaluated at similar two points. Neurocognitive evaluation was performed with standard neuropsychologic testing in both groups. Analysis of PET data consisted of standardized uptake value measurements in six relevant brain regions and a whole-brain voxel-based statistical approach. Results Participants were men (nine control participants [median age, 33 years; IQR, 32-36 years] and nine blast-exposed participants [median age, 33 years; IQR, 30-34 years]; P = .82). In the blast-exposed participants, four brain regions showed significantly increased amyloid deposition after blast exposure: inferomedial frontal lobe (P = .004), precuneus (P = .02), anterior cingulum (P = .002), and superior parietal lobule (P = .003). No amyloid deposition was observed in the control participants. Discriminant analysis on the basis of regional changes of amyloid accumulation correctly classified the nine healthy control participants as healthy control participants (100%), and seven of the nine blast-exposed participants (78%) were correctly classified as blast exposed. Based on the voxel-based analysis, whole-brain parametric maps of early abnormal early amyloid uptake were obtained. Conclusion Early brain amyloid accumulation was identified and quantified at PET in otherwise healthy adult men exposed to repetitive subconcussive traumatic events. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Haller in this issue.


Asunto(s)
Traumatismos por Explosión , Lesiones Traumáticas del Encéfalo , Personal Militar , Masculino , Adulto Joven , Humanos , Adulto , Femenino , Traumatismos por Explosión/diagnóstico por imagen , Traumatismos por Explosión/complicaciones , Traumatismos por Explosión/psicología , Personal Militar/psicología , Péptidos beta-Amiloides/metabolismo , Estudios Prospectivos , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Amiloide/metabolismo , Lesiones Traumáticas del Encéfalo/complicaciones
3.
Semin Nucl Med ; 52(6): 797-805, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35738911

RESUMEN

Diseases of pleura are not only common but also have a significant impact on patients' outcomes. While early detection and treatment are imperative in reducing this burden, many pleural entities present similarly, thus posing a diagnostic dilemma for radiologists requiring critical further workup. While chest radiography, CT, and image-guided thoracentesis are primarily utilized as the initial imaging techniques for the workup of pleural diseases, MRI, and FDG-PET/CT are also frequently employed to investigate the root cause of pleural abnormalities. By elucidating the common imaging features of neoplastic, inflammatory, and infectious pleural pathologies, clinicians can quickly and easily differentiate the various pleural diseases, rapidly reach the correct diagnosis, and ultimately improve patient outcomes.


Asunto(s)
Pleura , Enfermedades Pleurales , Humanos , Pleura/patología , Fluorodesoxiglucosa F18 , Tomografía Computarizada por Tomografía de Emisión de Positrones/efectos adversos , Tomografía Computarizada por Rayos X , Enfermedades Pleurales/diagnóstico por imagen , Enfermedades Pleurales/etiología , Enfermedades Pleurales/patología
5.
Radiographics ; 41(2): 380-398, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33544664

RESUMEN

The digitization of radiographic studies along with high-speed transmission of images has formed the basis of teleradiology, which has become an integral component in the workflow of a contemporary radiology practice. It is with this advent and growing utilization of teleradiology that the significance of the source location of images has gained importance. Specifically, the importance of where the patient resides and what endemic fungi occur in that location cannot be underestimated. In the United States, histoplasmosis, coccidioidomycosis, blastomycosis, and cryptococcosis are caused by endemic fungi occurring in the Ohio and Mississippi river valleys, the Southwest, the Upper Midwest, and the Pacific Northwest, respectively. All of these organisms enter the body through the respiratory system and have the potential to cause significant morbidity and mortality. Patients infected with these fungi are often asymptomatic but may present with acute flulike symptoms such as fever, cough, or dyspnea. Patients may also present with vague chronic symptoms including cough, fever, malaise, and weight loss. Thoracic manifestations at radiography and CT include consolidation, nodules, cavities, lymphadenopathy, and pleural disease. PET may show fluorine 18-fluorodeoxyglucose uptake with active acute or chronic infections, and it is difficult to distinguish infections from malignancy. Imaging findings may be nonspecific and can be confused with other disease processes, including malignancy. The patient demographics, clinical history, and location are clues that may lead to a proper diagnosis of endemic fungal disease. The radiologist should be cognizant of the patient location to provide a correct and timely radiologic diagnosis that helps guide the clinician to initiate appropriate therapy. ©RSNA, 2021.


Asunto(s)
Blastomicosis , Coccidioidomicosis , Histoplasmosis , Micosis , Coccidioidomicosis/diagnóstico por imagen , Coccidioidomicosis/epidemiología , Hongos , Humanos , Estados Unidos/epidemiología
7.
J Thorac Imaging ; 35(3): 153-166, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32073541

RESUMEN

Tetrallogy of Fallot (TOF) is the most frequent form of cyanotic congenital heart disease. Despite advances in surgical and medical treatment, mortality remains high. Residual dysfunction of the pulmonary valve (PV) after correction of right ventricular outflow tract obstruction is an important cause of morbidity, leading to irreversible right ventricular dysfunction, arrhythmias, heart failure and occasionally, death. The strategies for PVR have evolved over the last decades, and the timing of the intervention remains the foundation of the decision-making process. Symptoms of heart failure are unreliable indicators for optimal timing of repair. Imaging plays an essential role in the assessment of PV integrity and dysfunction. The identification of the best timing for PVR requires a multimodality approach. Transthoracic echocardiography is the most commonly used imaging modality for the initial assessment and follow-up of TOF patients, although its utility has technical limitations, especially in adults. Cardiac computed tomography and magnetic resonance imaging are now routinely used for preoperative and postoperative evaluation of these patients, and provide highly valuable information about the anatomy and pathophysiology. Imaging evidence of disease progression is now part of the major guidelines to define the best timing for reintervention. The purpose of this article is to review the pathophysiology after TOF repair, identify the main imaging anatomic and physiologic features, describe the indications for PVR and recognize the role of imaging in the assessment of these patients to define the appropriate timing of PVR.


Asunto(s)
Implantación de Prótesis de Válvulas Cardíacas , Complicaciones Posoperatorias/diagnóstico por imagen , Cuidados Preoperatorios/métodos , Válvula Pulmonar/diagnóstico por imagen , Válvula Pulmonar/cirugía , Tetralogía de Fallot/cirugía , Ecocardiografía/métodos , Humanos , Imagen por Resonancia Magnética/métodos , Complicaciones Posoperatorias/cirugía , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento
8.
Respir Res ; 20(1): 216, 2019 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-31604436

RESUMEN

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease involving progressive degeneration of lung capacity. Current diagnosis of IPF heavily relies on visual evaluation of fibrotic features in high-resolution computed tomography (HRCT) images of the lungs. Although the characteristics of this disease have been studied at the molecular and cellular levels, little is known about the mechanical characteristics of IPF lungs inferred from HRCT images. To this end, we performed a pilot study to investigate the radiographic and volumetric characteristics of lungs in subjects with IPF. METHODS: We collected HRCT images of healthy (N = 13) and IPF (N = 9) lungs acquired at breath-holds after full inspiration (expanded state) and full expiration (contracted state). We performed statistical analyses on Hounsfield unit (HU) histograms, lobar volumes (V: lobe volume normalized by the lung volume), and lobar flows (Q: the difference in lobe volume divided by the difference in lung volume between the expanded and contracted states). RESULTS: Parameters characterizing the HU histograms (i.e., mean, median, skewness, and kurtosis) significantly differed between healthy and IPF subjects, for all lobes in both expanded and contracted states. The distribution of V across lobes differed significantly between the groups in both states. The distribution of Q also differed significantly between the groups: Q values of the lower lobes for the IPF group were 33% (right) and 22% (left) smaller than those for the healthy group, consistent with the observation that radiographic scores were highest in the lower lung section in IPF. Notably, the root-mean-squared difference (RMSD) of Q, a measure of distance from the mean value of the healthy group, clearly distinguished the IPF subjects (RMSD of Q > 1.59) from the healthy group (RMSD of Q < 0.67). CONCLUSION: This study shows that lung volume and flow distribution change heterogeneously across the lung lobes of IPF subjects, with reduced capacity in the lower lobes. These volumetric changes may improve our understanding of the pathophysiology in IPF lungs.


Asunto(s)
Fibrosis Pulmonar Idiopática/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Pulmón/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Anciano , Femenino , Humanos , Fibrosis Pulmonar Idiopática/fisiopatología , Mediciones del Volumen Pulmonar , Masculino , Persona de Mediana Edad , Proyectos Piloto , Pruebas de Función Respiratoria , Mecánica Respiratoria
9.
Mayo Clin Proc Innov Qual Outcomes ; 3(1): 86-93, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30899912

RESUMEN

OBJECTIVE: To describe the clinical characteristics and outcomes of patients diagnosed with obliterative bronchiolitis (OB) not associated with transplantation or point-source exposures to inhaled toxins. PATIENTS AND METHODS: We compiled all confirmed diagnoses of OB at our institution and analyzed their demographic characteristics, treatments, and outcomes as defined by pulmonary function tests (PFTs) and transplant-free mortality. The study period ranged from July 2007 to August 2017. Histological diagnosis was confirmed by a pathologist, and high-resolution chest computed tomography (CT) scans were reviewed and scored by chest radiologists. We also performed a systematic literature review of sporadic OB series. RESULTS: We identified 19 confirmed cases at our institution and 9 publications in the literature containing 104 patients. In both our series and the literature, patients were disproportionately middle-aged Caucasian women. The disease was idiopathic in 42% and was associated with connective tissue diseases and inhalational exposures in 31% and 15%, respectively. Chest CT showed expiratory air trapping in all patients. Patients were treated with corticosteroids, steroid-sparing agents, and macrolides in 77%, 46%, and 22%, respectively. Over a median follow-up in our series of 1703 days (range, 11-3206 days), PFTs did not change significantly. In all series combined, mortality incidence from any cause was 82/1000 patient-years (95% CI, 65-102). Of 14 patients who died, 3 deaths were due to respiratory failure and 5 were potentially related to complications of immunosuppressive therapy. CONCLUSION: Sporadic OB is a rare disease that is uniformly associated with air trapping on high-resolution chest CT. The diagnosis should be established with surgical biopsy if possible. The illness is not typically progressive.

11.
AJR Am J Roentgenol ; 212(2): 425-430, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30422717

RESUMEN

OBJECTIVE: The purpose of this study was to determine whether relative standardized uptake value (SUV) measurements at FDG PET/MRI coregistration are predictive of local tumor control in patients with brain metastases treated with stereotactic radiosurgery (SRS). MATERIALS AND METHODS: A retrospective review was conducted of the images and clinical characteristics of a cohort of patients with brain metastases from non-CNS neoplasms treated with gamma knife radiosurgery (GKRS) who underwent posttherapy FDG PET because of MRI findings concerning for progression. The PET and contrast-enhanced MR images were fused. Relative SUV measurements were calculated from ROIs placed in the area of highest FDG uptake within the enhancing lesion and in the contralateral normal-appearing white matter. Relative SUV was defined as the ratio of maximum SUV in the tumor to maximum SUV in healthy white matter. Two independent readers evaluated response to GKRS using serial posttherapy MRI performed at least 3 months after GKRS completion. The relation between relative SUV and local tumor progression was evaluated with respect to treatment effect. RESULTS: Eighty-five patients (48 [56.5%] women, 37 [43.5%] men; mean age at diagnosis, 60.5 ± 11.3 years) met the inclusion criteria. Thirty-three (38.8%) lesions progressed after SRS. There was a significant association between relative SUV and local tumor control (p = 0.035). Relative SUV provided a diagnostic ROC AUC of 0.67 (95% CI, 0.55-0.79). CONCLUSION: Quantitative relative SUV at posttherapy FDG PET serves as a biomarker of response to SRS in patients with brain metastases in cases in which lesion growth is identified at follow-up MRI. This prognostic data may affect management, supporting the need for further therapeutic actions for selected patients.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/cirugía , Fluorodesoxiglucosa F18 , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Radiofármacos , Radiocirugia , Neoplasias Encefálicas/secundario , Femenino , Humanos , Masculino , Persona de Mediana Edad , Imagen Multimodal , Neuroimagen , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Resultado del Tratamiento
12.
Acad Radiol ; 26(3): 412-423, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30195415

RESUMEN

RATIONALE AND OBJECTIVES: We propose an automated segmentation pipeline based on deep learning for proton lung MRI segmentation and ventilation-based quantification which improves on our previously reported methodologies in terms of computational efficiency while demonstrating accuracy and robustness. The large data requirement for the proposed framework is made possible by a novel template-based data augmentation strategy. Supporting this work is the open-source ANTsRNet-a growing repository of well-known deep learning architectures first introduced here. MATERIALS AND METHODS: Deep convolutional neural network (CNN) models were constructed and trained using a custom multilabel Dice metric loss function and a novel template-based data augmentation strategy. Training (including template generation and data augmentation) employed 205 proton MR images and 73 functional lung MRI. Evaluation was performed using data sets of size 63 and 40 images, respectively. RESULTS: Accuracy for CNN-based proton lung MRI segmentation (in terms of Dice overlap) was left lung: 0.93 ± 0.03, right lung: 0.94 ± 0.02, and whole lung: 0.94 ± 0.02. Although slightly less accurate than our previously reported joint label fusion approach (left lung: 0.95 ± 0.02, right lung: 0.96 ± 0.01, and whole lung: 0.96 ± 0.01), processing time is <1 second per subject for the proposed approach versus ∼30 minutes per subject using joint label fusion. Accuracy for quantifying ventilation defects was determined based on a consensus labeling where average accuracy (Dice multilabel overlap of ventilation defect regions plus normal region) was 0.94 for the CNN method; 0.92 for our previously reported method; and 0.90, 0.92, and 0.94 for expert readers. CONCLUSION: The proposed framework yields accurate automated quantification in near real time. CNNs drastically reduce processing time after offline model construction and demonstrate significant future potential for facilitating quantitative analysis of functional lung MRI.


Asunto(s)
Aprendizaje Profundo , Pulmón/diagnóstico por imagen , Pulmón/fisiología , Imagen por Resonancia Magnética , Simulación por Computador , Conjuntos de Datos como Asunto , Humanos , Protones , Ventilación Pulmonar
14.
AJR Am J Roentgenol ; 210(4): 869-875, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29446671

RESUMEN

OBJECTIVE: The purpose of this study was to determine whether unenhanced MRI without sedation is a feasible substitute for dimercaptosuccinic acid (DMSA) scintigraphy in the detection of renal scars in pediatric patients. SUBJECTS AND METHODS: Patients scheduled for 99mTc-labeled DMSA scintigraphy for assessment of possible renal scars were recruited to undergo unenhanced MRI (free-breathing fat-suppressed T2-weighted single-shot turbo spin-echo and T1-weighted gradient-echo imaging, 13 minutes' total imaging time). Scintigraphic and MRI studies were evaluated by two independent blinded specialty-based radiologists. For each imaging examination, readers identified scars in upper, middle, and lower kidney zones and rated their diagnostic confidence and the quality of each study. The scintigraphic readers' consensus score opinion for the presence of scars was considered the reference standard. RESULTS: DMSA scintigraphy showed scarring in 19 of the 78 (24.4%) evaluated zones and MRI in 18 of the 78 (23.1%). The two MRI readers found mean sensitivities of 94.7% and 89.5%, identical specificities of 100%, and diagnostic accuracies of 98.7% and 97.4%. Interobserver agreement was 98.7% for MRI and 92.3% for DMSA scintigraphy. The MRI readers were significantly more confident in determining the absence rather than the presence of scars (p = 0.02). MRI readers were more likely to rate study quality as excellent (84.6%) than were the scintigraphic readers (57.7%) (p = 0.024). CONCLUSION: Unenhanced MRI has excellent sensitivity, specificity, diagnostic accuracy, and interobserver agreement for detecting renal scars in older children who do not need sedation. It may serve as a substitute modality, especially when DMSA is not available.


Asunto(s)
Cicatriz/diagnóstico por imagen , Enfermedades Renales/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Cintigrafía/métodos , Radiofármacos/administración & dosificación , Ácido Dimercaptosuccínico de Tecnecio Tc 99m/administración & dosificación , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Sensibilidad y Especificidad
15.
Epilepsy Res ; 138: 105-109, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29100172

RESUMEN

OBJECTIVE: To study the relationship of glucose metabolism and volume of the temporal lobes with age at epilepsy onset, epilepsy duration, and seizure frequency in patients with mesial temporal sclerosis (MTS). METHODS: We evaluated the pre-surgical 18F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) and magnetic resonance imaging (MRI) of 18 patients with epilepsy and MRI findings of MTS, who were seizure-free for at least 2-years after temporal lobectomy. We calculated the volume of the hippocampi and amygdalae on MRI. On PET we studied their mean standard uptake values (SUV), and relative metabolic activity as compared to normal subjects in terms of Z-scores. We compared the PET and MRI metrics in the bilateral structures using the Wilcoxon sign rank test. We studied the relationship between the imaging metrics and age of epilepsy onset, epilepsy duration, and seizure frequency via Spearman correlation analyses. RESULTS: Younger age at onset correlated with decreased hippocampal glucose metabolism (rs=0.64, p=0.008). Longer epilepsy duration correlated with decreased hippocampal glucose metabolism (rs=-0.55, p=0.024). There was no correlation between age at onset of epilepsy, epilepsy duration, or seizure frequency and volumetrics. Z-score in the sclerotic hippocampus (-3.51±2.2vs -0.7±1.7) and amygdala (-3.26±2.3 vs -0.68±1.8) was smaller than the contralateral (p<0.001). The diseased hippocampus (2.84±0.49 vs 3.52±0.4ml) and ipsilateral amygdala (1.49±0.24 vs 1.72±0.3ml) were significantly smaller than the contralateral (p<0.02). SIGNIFICANCE: Earlier epilepsy onset correlated with hippocampal hypometabolism. Longer epilepsy duration correlated with amygdalar hypometabolism suggesting an ongoing progressive disease in MTLE.


Asunto(s)
Epilepsia del Lóbulo Temporal/complicaciones , Epilepsia del Lóbulo Temporal/patología , Hipocampo/diagnóstico por imagen , Enfermedades Metabólicas/etiología , Adulto , Edad de Inicio , Amígdala del Cerebelo/diagnóstico por imagen , Amígdala del Cerebelo/patología , Electroencefalografía , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Fluorodesoxiglucosa F18/farmacología , Glucosa/metabolismo , Hipocampo/metabolismo , Humanos , Imagen por Resonancia Magnética , Masculino , Enfermedades Metabólicas/diagnóstico por imagen , Persona de Mediana Edad , Tomografía de Emisión de Positrones , Estudios Retrospectivos , Esclerosis/etiología , Esclerosis/patología , Estadísticas no Paramétricas , Factores de Tiempo
16.
J Thorac Imaging ; 32(5): 323-332, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28221241

RESUMEN

PURPOSE: The aim of the study was to determine whether hyperpolarized He diffusion-weighted magnetic resonance imaging detects abnormalities in the lungs in children with bronchopulmonary dysplasia (BPD) as compared with age-matched normal children. MATERIALS AND METHODS: All experiments were compliant with Health Insurance Portability and Accountability Act (HIPAA) and performed with Food and Drug Administration approval under an IND application. The protocol was approved by our Institutional Review Board, and written informed consent was obtained. Hyperpolarized He diffusion-weighted magnetic resonance imaging was performed in 16 subjects with a history of preterm birth complicated by BPD (age range, 6.8 to 13.5 y; mean, 9.0 y) and in 29 healthy term-birth subjects (age range, 4.5-14.7 y; mean, 9.2 y) using a gradient-echo sequence with bipolar diffusion gradients and with measurements at 2 b values (0 and 1.6 s/cm). Age-related comparison of the whole-lung mean apparent diffusion coefficient (ADC), 90th percentile ADC, and percentage of whole-lung volume with ADC>0.2 cm/s between the 2 groups was examined using ordinary least-squares multiple regression. RESULTS: The mean ADC was significantly greater in subjects with BPD (0.187 vs. 0.152 cm/s, P<0.001). The 90th percentile ADC and mean percentage lung volume with ADC>0.2 cm/s were also higher in the BPD group (0.258 vs. 0.215 cm/s, 30.3% vs. 11.9%, P<0.001 for both). The body surface area-adjusted ventilated lung volume was similar in the 2 groups (1.93 vs. 1.91 L, P=0.90). CONCLUSIONS: Children with BPD had higher ADCs and the same lung volumes when compared with age-matched healthy subjects, suggesting that children with BPD have enlarged alveoli that are reduced in number.


Asunto(s)
Displasia Broncopulmonar/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos , Helio , Isótopos , Pulmón/anomalías , Pulmón/diagnóstico por imagen , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino
17.
Radiology ; 283(2): 508-514, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28234553

RESUMEN

Purpose To determine the correlation between metabolic activity at fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and survival in patients with glioblastoma and suspected progression at posttherapy magnetic resonance (MR) imaging. Materials and Methods The authors retrospectively examined the relationship between metabolic activity at FDG PET in the residual lesion identified at brain MR imaging and survival time in 56 patients with glioblastoma who were treated with postoperative concurrent radiation and temozolomide therapy and who underwent FDG PET/computed tomography because of radiologic deterioration at follow-up MR imaging between 2006 and 2015. A normalized metric of metabolic activity in the residual lesion (standardized uptake value ratio [SUVr]) was calculated as the maximum standardized uptake value (SUVmax) in the tumor relative to that in healthy white matter. The primary end point of the study was survival time from PET. Patients were stratified according to SUVr. Comparisons of risk for death between subgroups were made with the log-hazard ratio of the Cox proportional hazard model. Results There was a significant association between overall survival and SUVr in the residual lesion (P = .006), and a survival benefit was observed in patients with SUVr of less than 1.7, who had a median survival time of 23.1 months (95% confidence interval [CI]: 12.7, 38.9), which was significantly longer than that in patients with an SUVr of 2.0 to less than 2.5 and those with an SUVr of at least 2.5, who had a median survival time of 10.1 (95% CI: 2.4, 15.9; P = .008) and 7.5 (95% CI: 3.9, 9.7; P < .001) months, respectively. Conclusion Patients with glioblastoma whose posttherapy MR images showed a residual lesion with high relative metabolic activity at FDG PET had a shorter survival time than did those with low activity at FDG PET. © RSNA, 2016.


Asunto(s)
Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/terapia , Glioblastoma/mortalidad , Glioblastoma/terapia , Imagen Multimodal/métodos , Recurrencia Local de Neoplasia/mortalidad , Neoplasias Encefálicas/diagnóstico por imagen , Femenino , Fluorodesoxiglucosa F18 , Glioblastoma/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Imagen Multimodal/estadística & datos numéricos , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/prevención & control , Tomografía de Emisión de Positrones/estadística & datos numéricos , Prevalencia , Pronóstico , Radiofármacos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Medición de Riesgo/métodos , Sensibilidad y Especificidad , Análisis de Supervivencia , Virginia/epidemiología
18.
Neuroradiology ; 58(11): 1135-1141, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27590748

RESUMEN

INTRODUCTION: The aims of the study were to compare the diagnostic performance of a combination of virtual non-contrast (VNC) images and arterial images obtained from a single-phase dual-energy CT (DECT) acquisition and standard non-contrast and arterial images from a biphasic protocol and to study the potential radiation dose reduction of the former approach. METHODS: All DECT examinations performed for evaluation of parathyroid adenomas during a 13-month period were retrospectively reviewed. An initial single-energy unenhanced acquisition was followed by a dual-energy arterial phase acquisition. "Virtual non-contrast images" were generated from the dual-energy acquisition. Two independent and blinded radiologists evaluated three different sets of images during three reading sessions: single arterial phase, single-phase DECT (virtual non-contrast and arterial phase), and standard biphasic protocol (true non-contrast and arterial phase). The accuracy of interpretation in lateralizing an adenoma to the side of the neck and localizing it to a quadrant in the neck was evaluated. RESULTS: Sixty patients (mean age, 65.5 years; age range, 38-87 years) were included in the study. The lateralization and localization accuracy, sensitivity, and positive predicted value (PPV) and negative predicted value (NPV) of the different image datasets were comparable. The combination of VNC and arterial images was more specific than arterial images alone to lateralize a parathyroid lesion (OR = 1.93, p = 0.043). The use of the single-phase protocol resulted in a calculated radiation exposure reduction of 52.8 %. CONCLUSIONS: Virtual non-contrast and arterial images from a single DECT acquisition showed similar diagnostic accuracy than a biphasic protocol, providing a significant dose reduction.


Asunto(s)
Adenoma/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Neoplasias de las Paratiroides/diagnóstico por imagen , Exposición a la Radiación/análisis , Exposición a la Radiación/prevención & control , Protección Radiológica/métodos , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
19.
J Thorac Imaging ; 31(5): 285-95, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27428024

RESUMEN

The assessment of early pulmonary disease and its severity can be difficult in young children, as procedures such as spirometry cannot be performed on them. Computed tomography provides detailed structural images of the pulmonary parenchyma, but its major drawback is that the patient is exposed to ionizing radiation. In this context, magnetic resonance imaging (MRI) is a promising technique for the evaluation of pediatric lung disease, especially when serial imaging is needed. Traditionally, MRI played a small role in evaluating the pulmonary parenchyma. Because of its low proton density, the lungs display low signal intensity on conventional proton-based MRI. Hyperpolarized (HP) gases are inhaled contrast agents with an excellent safety profile and provide high signal within the lung, allowing for high temporal and spatial resolution imaging of the lung airspaces. Besides morphologic information, HP MR images also offer valuable information about pulmonary physiology. HP gas MRI has already made new contributions to the understanding of pediatric lung diseases and may become a clinically useful tool. In this article, we discuss the HP gas MRI technique, special considerations that need to be made when imaging children, and the role of MRI in 2 of the most common chronic pediatric lung diseases, asthma and cystic fibrosis. We also will discuss how HP gas MRI may be used to evaluate normal lung growth and development and the alterations occurring in chronic lung disease of prematurity and in patients with a congenital diaphragmatic hernia.


Asunto(s)
Enfermedades Pulmonares/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Adolescente , Niño , Preescolar , Humanos , Lactante , Adulto Joven
20.
Pediatr Radiol ; 46(3): 422-5, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26515448

RESUMEN

Noonan syndrome is a constellation of congenital malformations including heart defects, facial anomalies and short stature. The cardiovascular defects are variable and extensive, with the most common being pulmonary stenosis and hypertrophic cardiomyopathy. Coronary artery anomalies have only been reported in a few cases. We report a child with Noonan syndrome status post pulmonary stenosis and atrial septal defect repair, who developed bilateral coronary artery aneurysms. The aneurysms were diagnosed with both cardiac magnetic resonance imaging and coronary computed tomography angiography. There had been no evidence of them on a cardiac MR exam 5 years previously.


Asunto(s)
Angiografía por Tomografía Computarizada/métodos , Aneurisma Coronario/diagnóstico por imagen , Angiografía Coronaria/métodos , Angiografía por Resonancia Magnética/métodos , Síndrome de Noonan/diagnóstico por imagen , Niño , Diagnóstico Diferencial , Humanos , Masculino
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