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ABSTRACT: Oncocytomas in the parotid gland are a rare benign neoplasm composed of mitochondrial-rich oncocytes. Here we present the case of an 85-year-old man with a history of biopsy-proven right parotid gland oncocytoma who underwent 99mTc-sestamibi scintigraphy and SPECT/CT in the context of primary hyperparathyroidism. Focal intense uptake of radiotracer is detected within the right parotid gland on sestamibi scintigraphy. SPECT/CT confirms the localization of sestamibi uptake to the hyperattenuating parotid gland oncocytoma.
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Adenoma Oxifílico/diagnóstico por imagen , Glándula Parótida/diagnóstico por imagen , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Tecnecio Tc 99m Sestamibi , Adenoma Oxifílico/patología , Anciano de 80 o más Años , Biopsia , Humanos , Masculino , Glándula Parótida/patologíaRESUMEN
Renal cell carcinoma (RCC) accounts for 2-3% of all adult malignancies. Clear-cell type RCC is the most common type, accounting for approximately 75% of all renal cancer cases. The most common sites of metastasis include the lung, bone, and liver. Ovarian metastasis of RCC is an exceptionally rare occurrence with only 41 cases reported in the literature with only 11 of these cases involving the bilateral ovaries. Here we present a case of clear-cell RCC arising from the left kidney with metastatic involvement of bilateral ovaries in a 48-year-old woman.
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Carcinoma de Células Renales , Neoplasias Renales , Neoplasias Ováricas , Adulto , Carcinoma de Células Renales/diagnóstico por imagen , Femenino , Humanos , Neoplasias Renales/diagnóstico por imagen , Persona de Mediana Edad , Neoplasias Ováricas/diagnóstico por imagenRESUMEN
Hibernoma is a rare benign neoplasm of brown adipose tissue most frequently involving the thigh, shoulder, back, and neck. Differentiating this benign entity from other lipomatous tumors such as well-differentiated liposarcoma is essential, given the different surgical approaches and prognosis associated with each diagnosis. It is helpful for the radiologist to recognize the uncommon locations of hibernoma, as well as characteristic imaging features, in order to properly include it in the differential considerations. Here we present a rare case of symptomatic vulvar hibernoma in a 25-year-old woman treated with surgical excision.
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A 48-y-old man with a history of colon cancer presented with recurrent hepatic metastasis along a prior microwave ablation bed. Split-bolus, intraprocedural 18F-FDG PET was performed to guide repeat microwave ablation and immediately confirm complete treatment. PET-guided ablation is highly accurate for targeting and treating malignant hepatic lesions and feasible for nonspecialized tertiary care hospitals without an onsite cyclotron.
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Técnicas de Ablación , Fluorodesoxiglucosa F18 , Neoplasias Hepáticas/cirugía , Microondas , Tomografía Computarizada por Tomografía de Emisión de Positrones , Dosis de Radiación , Cirugía Asistida por Computador , Neoplasias del Colon/patología , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , RecurrenciaRESUMEN
Traumatic brain injury (TBI) is a significant problem worldwide and neuroimaging plays a critical role in diagnosis and management. Recently, perfusion neuroimaging techniques have been explored in TBI to determine and characterize potential perfusion neuroimaging biomarkers to aid in diagnosis, treatment, and prognosis. In this article, computed tomography (CT) bolus perfusion, MR imaging bolus perfusion, MR imaging arterial spin labeling perfusion, and xenon CT are reviewed with a focus on their applications in acute TBI. Future research directions are also discussed.
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Lesiones Encefálicas/diagnóstico por imagen , Diagnóstico por Imagen/métodos , Imagen de Perfusión/métodos , Encéfalo/diagnóstico por imagen , Humanos , Neuroimagen/métodosRESUMEN
INTRODUCTION: Epidermal growth factor receptor (EGFR) protein expression in non-small cell lung cancer (NSCLC) is not recommended for predicting response to EGFR tyrosine kinase inhibitors (TKI) due to conflicting results, all using antibodies detecting EGFR external domain (ED). We tested the predictive value of EGFR protein expression for response to an EGFR TKI with an antibody that detects the intracellular domain (ID) and compared fluorescence-based Automated QUantitative Analysis (AQUA) technology to immunohistochemistry (IHC). METHODS: Specimens from 98 gefitinib-treated NSCLC Japanese patients were evaluated by IHC (n = 98 of 98) and AQUA technology (n = 70 of 98). EGFR ID (5B7)- and ED-specific antibodies (3C6 and 31G7) were compared. RESULTS: EGFR expression evaluated with 5B7 was significantly higher in responders versus nonresponders to gefitinib both with IHC and with AQUA. ED-specific antibodies did not significantly predict response. Using AQUA and ID-specific antibody resulted in the best prediction performance with a positive and negative predictive value (PPV/NPV) for responders of 50% and 87%, respectively. EGFR expression with ID-specific antibody and AQUA also predicted responders in EGFR-mutated patients. Increased EGFR expression with the ID antibody is associated with increased median progression free survival (PFS; 11.7 months vs. 5.0, log rank, P = 0.034) and overall survival (OS; 38.6 vs. 14.9, P = 0.040) from gefitinib therapy. CONCLUSIONS: EGFR protein expression using an ID-specific antibody specifically predicts response to gefitinib in NSCLC patients, including in EGFR-mutated patients, and increased PFS/OS from gefitinib. These data suggest that the choice of diagnostic antibody and methodology matters to predict response and outcome to specific therapies. The potential clinical application needs further validation. Clin Cancer Res; 17(24); 7796-807. ©2011 AACR.
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Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Receptores ErbB/antagonistas & inhibidores , Neoplasias Pulmonares/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Sitios de Unión , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Receptores ErbB/biosíntesis , Receptores ErbB/genética , Femenino , Técnica del Anticuerpo Fluorescente/métodos , Gefitinib , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Inmunohistoquímica/métodos , Estimación de Kaplan-Meier , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Persona de Mediana Edad , Análisis Multivariante , Mutación , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Pronóstico , Modelos de Riesgos Proporcionales , Quinazolinas/uso terapéutico , Análisis de Matrices TisularesRESUMEN
Vascular-space-occupancy (VASO) MRI is a novel technique that uses blood signal nulling to detect blood volume alterations through changes in tissue signal. VASO has relatively low signal to noise ratio (SNR) because only 10-20% of tissue signal remain at the time of blood nulling. Here, it is shown that by adding a magnetization transfer (MT) prepulse it is possible to increase SNR either by attenuating the initial tissue magnetization when the MT pulse is placed before inversion, or, accelerating the recovery process when the pulse is applied after the inversion. To test whether the MT pulse would affect the blood nulling time in VASO, MT effects in blood were measured both ex vivo in a bovine blood phantom and in vivo in human brain. Such effects were found to be sufficiently small (<2.5%) under a saturation power
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Algoritmos , Velocidad del Flujo Sanguíneo/fisiología , Mapeo Encefálico/métodos , Circulación Cerebrovascular/fisiología , Potenciales Evocados Visuales/fisiología , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Corteza Visual/fisiología , Humanos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Corteza Visual/irrigación sanguíneaRESUMEN
Liposome-based chemical exchange saturation transfer (lipoCEST) agents have shown great sensitivity and potential for molecular magnetic resonance imaging (MRI). Here we demonstrate that the size of liposomes can be exploited to enhance the lipoCEST contrast. A concise analytical model is developed to describe the contrast dependence on size for an ensemble of liposomes. The model attributes the increased lipoCEST contrast in smaller liposomes to their larger surface-to-volume ratio, causing an increased membrane water exchange rate. Experimentally measured rates correlate with size, in agreement with the model. The water permeability of liposomal membrane is found to be 1.11 +/- 0.14 microm/s for the specific lipid composition at 22 degrees C. Availability of the model allows rational design of the size of liposomes and quantification of their properties. These new theoretical and experimental tools are expected to benefit applications of liposomes to sensing the cellular environment, targeting and imaging biological processes, and optimizing drug delivery properties.
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Liposomas/químicaRESUMEN
Knowledge of the transverse relaxation rates R2 and R2* of blood is relevant for quantitative assessment of functional MRI (fMRI) results, including calibration of blood oxygenation and measurement of tissue oxygen extraction fractions (OEFs). In a temperature controlled circulation system, these rates were measured for blood in vitro at 3T under conditions akin to the physiological state. Single spin echo (SE) and gradient echo (GRE) sequences were used to determine R2 and R2*, respectively. Both rates varied quadratically with deoxygenation, and changes in R2* were found to be due predominantly to changes in R2. These data were used to estimate intravascular blood oxygenation level dependent (BOLD) contributions during visual activation. Due to the large R2* in venous blood, intravascular SE BOLD signal changes were larger than GRE effects at echo times above 30 ms. When including extravascular effects to estimate the total BOLD effect, GRE BOLD dominated due to the large tissue volume fraction.