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1.
AJNR Am J Neuroradiol ; 45(5): 581-587, 2024 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-38548307

RESUMO

BACKGROUND AND PURPOSE: Spontaneous intracerebral hemorrhage is a serious stroke subtype with high mortality and morbidity. Minimally invasive surgery plus thrombolysis is a promising treatment option, but it requires accurate catheter placement and real-time monitoring. The authors introduced IV flat detector CT angiography (ivFDCTA) into the minimally invasive surgery procedure for the first time, to provide vascular information and guidance for hematoma evacuation. MATERIALS AND METHODS: Thirty-six patients with hypertensive intracerebral hemorrhage were treated with minimally invasive surgery under the guidance of ivFDCTA and flat detector CT (FDCT) in the angiography suite. The needle path and puncture depth were planned and calculated using software on the DSA workstation. The hematoma volume reduction, operation time, complications, and clinical outcomes were recorded and evaluated. RESULTS: The mean preoperative hematoma volume of 36 patients was 35 (SD, 12) mL, the mean intraoperative volume reduction was 19 (SD, 11) mL, and the mean postoperative residual hematoma volume was 15 (SD, 8) mL. The average operation time was 59 (SD, 22) minutes. One patient had an intraoperative epidural hematoma, which improved after conservative treatment. The mean Glasgow Outcome Scale score at discharge was 4.3 (SD, 0.8), and the mean mRS score at 90 days was 2.4 (SD, 1.1). CONCLUSIONS: The use of ivFDCTA in the evacuation of an intracerebral hemorrhage hematoma could improve the safety and efficiency of minimally invasive surgery and has shown great potential in hemorrhagic stroke management in selected patients.


Assuntos
Angiografia por Tomografia Computadorizada , Hemorragia Intracraniana Hipertensiva , Procedimentos Cirúrgicos Minimamente Invasivos , Cirurgia Assistida por Computador , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/instrumentação , Hemorragia Intracraniana Hipertensiva/cirurgia , Hemorragia Intracraniana Hipertensiva/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Cirurgia Assistida por Computador/métodos , Resultado do Tratamento , Angiografia Cerebral/métodos , Adulto , Idoso de 80 Anos ou mais
2.
Front Endocrinol (Lausanne) ; 14: 1196935, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37396163

RESUMO

Background: Abnormally changed steroid hormones during pregnancy are closely related to the pathological process of gestational diabetes mellitus (GDM). Our aim was to systematically profile the metabolic alteration of circulating steroid hormones in GDM women and screen for risk factors. Methods: This study was a case-control study with data measured from 40 GDM women and 70 healthy pregnant women during their 24-28 gestational weeks. 36 kinds of steroid hormones, including 3 kinds of corticosteroids, 2 kinds of progestins, 5 kinds of androgens and 26 kinds of downstream estrogens in serum were systematically measured using a combined sensitive UPLC-MS/MS method. The flux of different metabolic pathways of steroid hormones was analyzed. Logistic regression and ROC curve model analyses were performed to identify potential steroid markers closely associated with GDM development. Results: Serum corticosteroids, progestins and almost all the estrogen metabolites via 16-pathway from parent estrogens were higher in GDM women compared with healthy controls. Most of the estrogen metabolites via 4-pathway and more than half of the metabolites via 2-pathway were not significantly different. 16α-hydroxyestrone (16OHE1), estrone-glucuronide/sulfate (E1-G/S) and the ratio of total 2-pathway estrogens to total estrogens were screened as three indicators closely related to the risk of GDM development. The adjusted odds ratios of GDM for the highest quartile compared with the lowest were 72.22 (95% CI 11.27-462.71, P trend <0.001) for 16OHE1 and 6.28 (95% CI 1.74-22.71, P trend <0.05) for E1-G/S. The ratio of 2-pathway estrogens to total estrogens was negatively associated with the risk of GDM. Conclusion: The whole metabolic flux from cholesterol to downstream steroid hormones increased in GDM condition. The most significant changes were observed in the 16-pathway metabolism of estrogens, rather than the 2- or 4-pathway or other types of steroid hormones. 16OHE1 may be a strong marker associated with the risk for GDM.


Assuntos
Diabetes Gestacional , Feminino , Gravidez , Humanos , Progestinas , Estudos de Casos e Controles , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem , Fatores de Risco , Estrogênios
3.
J Pharm Biomed Anal ; 221: 115044, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36126614

RESUMO

Gestational diabetes mellitus (GDM) is not only a threat to the health of pregnant women, but also has profound effects on the health of offspring. Studies have shown that the imbalance of estrogen metabolism is associated with an increased risk of GDM. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established and validated for simultaneous quantification of thirteen estrogens in the urine of GDM women, including estrone (E1), estradiol (E2), estriol (E3), and their hydroxylated and methylated metabolites. The method was achieved on a Waters CORTECS C18 column (2.1 mm × 150 mm, 1.6 µm) within 8.5 min. The linear range of thirteen estrogens in urine was 2-1000 pg·mL-1. Both intra- and inter-day precision for each analyte were less than 15%, with accuracies ranging from 8.3% to 7.3%. The extraction recoveries rate were between 86% and 111%, and stability verification results met the requirements for determination of biological samples. The results suggested that the concentrations of estrogens in all urine samples range from 0.08 to 134.06 (pg·mg-1 creatinine). The mean levels of E1, E2 and most estrogen metabolites in the urine of GDM women were higher than those in healthy pregnant women. Notably, the mean level of 2-hydroxyestrone (2-OHE1) in GDM women was 13.2-fold lower than that in healthy pregnant women. The types of estrogens with the highest mean levels in the urine of GDM and healthy pregnant women were obviously different, which are 2-methoxyestrone (2MeOE1) and E3, respectively. Our results demonstrated that this specific and sensitive method is suitable for quantifying estrogens in human urine and could provide support for further research on estrogen-related pathological mechanisms in GDM and other diseases.


Assuntos
Diabetes Gestacional , Estrogênios , Cromatografia Líquida/métodos , Creatinina , Estradiol , Estriol , Estrogênios/química , Estrona , Feminino , Humanos , Hidroxiestronas , Gravidez , Espectrometria de Massas em Tandem/métodos
4.
Reprod Sci ; 29(12): 3449-3458, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35835901

RESUMO

The purpose of this study is to explore the differences in the steroid metabolic network between hyperandrogenic and non-hyperandrogenic women with polycystic ovary syndrome (PCOS). A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the quantification of 36 kinds of serum steroids in 80 PCOS women during their follicular phase. Compared with those in non-hyperandrogenemia PCOS women (NA-PCOS), the levels of 17-hydroprogesterone (P = 0.009), androstenedione (P < 0.001), total testosterone (P < 0.001), dihydrotestosterone (P = 0.025), estrone (P = 0.007), and estradiol (P < 0.001) were increased in hyperandrogenemia PCOS (HA-PCOS) women. It was suggested that HA-PCOS may have increased activity of P450c17 (17-hydropregnenolone/pregnenolone, P = 0.008), 3ßHSD2 (androstenedione/dehydroepiandrosterone, P = 0.004), and 17ßHSD3 (testosterone/dehydroepiandrosterone, P = 0.01) and decreased activity of 5α reductase (dihydrotestosterone/testosterone, P = 0.008). Moreover, the ratio of luteinizing hormone (LH) to follicle stimulating hormone (FSH) was found to be related to these increased steroids and enzyme activities. In conclusion, the HA-PCOS and the NA-PCOS women showed different steroid profiles, and the different enzyme activities in steroidogenic pathway may be the main reason for the difference.


Assuntos
Hiperandrogenismo , Síndrome do Ovário Policístico , Feminino , Humanos , Síndrome do Ovário Policístico/complicações , Cromatografia Líquida , Espectrometria de Massas em Tandem , Hiperandrogenismo/complicações , Androstenodiona , Hormônio Luteinizante , Testosterona , Esteroides
5.
Biomed Res Int ; 2022: 8644356, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35036441

RESUMO

The aim of the present study was to investigate the effects and mechanism of oxymatrine (OMT) combined with compound yinchen granules (CYG) on the apoptosis of hepatocytes through the Akt/FoxO3a/Bim pathway in rats with acute liver failure. The rat model of acute liver failure was established using lipopolysaccharide/D-galactosamine (LPS/D-GalN). The expression of proteins in rat liver tissues was detected by western blot analysis. The mRNA expression of FoxO3a, Bim, Bax, Bcl-2, and caspase-3 in rat liver tissues was detected by RT-qPCR. The apoptosis rate of rat hepatocytes was determined by flow cytometry. Western blots showed that when compared with the normal group, the expression of p-Akt and p-FoxO3a in the model group was decreased (P < 0.05), while the expression of Bim was increased (P < 0.01). Compared with the model group, the expression of p-Akt and p-FoxO3a in the OMT group and the OMT combined with CYG groups was increased (P < 0.05 or P < 0.01), while the expression of Bim was decreased (P < 0.05). The Bax/Bcl-2 ratio and caspase-3 protein expression in the model group were significantly higher than those in the normal group (P < 0.01). The Bax/Bcl-2 ratio and the expression of caspase-3 protein in the OMT group and the OMT combined with CYG groups were significantly lower than those in the model group (P < 0.01). The results of RT-qPCR were consistent with those of western blot. The results of flow cytometry showed that the apoptosis rate of hepatocytes in the OMT group and the OMT combined with CYG groups was significantly lower than that in the model group (P < 0.05 or P < 0.01). We concluded that LPS/D-GalN can induce apoptosis of hepatocytes in rats with acute liver failure through the Akt/FoxO3a/Bim pathway. OMT combined with CYG inhibits apoptosis of hepatocytes in rats with acute liver failure via the Akt/FoxO3a/Bim pathway.


Assuntos
Alcaloides/farmacologia , Apoptose/efeitos dos fármacos , Proteína 11 Semelhante a Bcl-2/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Proteína Forkhead Box O3/metabolismo , Hepatócitos/metabolismo , Falência Hepática Aguda/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Quinolizinas/farmacologia , Transdução de Sinais , Animais , Artemisia , Hepatócitos/patologia , Falência Hepática Aguda/tratamento farmacológico , Masculino , Ratos , Ratos Sprague-Dawley
6.
Phys Med Biol ; 61(6): 2552-61, 2016 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-26954591

RESUMO

In radiation therapy, fiducial markers are often implanted near tumors and used for patient positioning and respiratory gating purposes. These markers are then used to manually align the patients by matching the markers in the cone beam computed tomography (CBCT) reconstruction to those in the planning CT. This step is time-intensive and user-dependent, and often results in a suboptimal patient setup. We propose a fully automated, robust method based on dynamic programming (DP) for segmenting radiopaque fiducial markers in CBCT projection images, which are then used to automatically optimize the treatment couch position and/or gating window bounds. The mean of the absolute 2D segmentation error of our DP algorithm is 1.3 ± 1.0 mm for 87 markers on 39 patients. Intrafraction images were acquired every 3 s during treatment at two different institutions. For gated patients from Institution A (8 patients, 40 fractions), the DP algorithm increased the delivery accuracy (96 ± 6% versus 91 ± 11%, p < 0.01) compared to the manual setup using kV fluoroscopy. For non-gated patients from Institution B (6 patients, 16 fractions), the DP algorithm performed similarly (1.5 ± 0.8 mm versus 1.6 ± 0.9 mm, p = 0.48) compared to the manual setup matching the fiducial markers in the CBCT to the mean position. Our proposed automated patient setup algorithm only takes 1-2 s to run, requires no user intervention, and performs as well as or better than the current clinical setup.


Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Posicionamento do Paciente/métodos , Algoritmos , Tomografia Computadorizada de Feixe Cônico/normas , Marcadores Fiduciais , Humanos , Posicionamento do Paciente/normas
7.
Invest Ophthalmol Vis Sci ; 55(12): 7848-61, 2014 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-25406277

RESUMO

PURPOSE: To identify differential changes in proteins and metabolites underlying "fast" type 1 (T1DC) and "slow" type 2 (T2DC) diabetic cataract (DC) formation in rat. METHODS: Rat models of types 1 and 2 diabetes consisted of streptozotocin injection without and with high-fat diet, respectively. Cataract progression was examined weekly. At week 6, total protein changes were comparatively and quantitatively assessed by two-dimensional differential in-gel electrophoresis (2-D DIGE) coupled with mass spectrometry, and relevant metabolic changes were examined. Differences in high molecular weight (HMW) crystallin species between diabetic and control lenses were similarly identified. RESULTS: Cataracts were morphologically different and progressed more slowly in T2DC versus T1DC. αA-crystallin, ßB2-crystallin, and ßA4-crystallin were significantly decreased in both DC types versus control. αB-crystallin was increased while ßB1-crystallin was markedly decreased in T2DC. In T1DC, γB-crystallin and γS-crystallin fragmentation were increased. High-fat diet by itself had little impact, except for lowering γS-crystallin fragmentation. Despite significantly decreased opacity, a greater decrease in intermediate filaments (IFs) and more HMW crystallin species were observed in T2DC versus T1DC. However, aldose reductase expression and activity and sorbitol levels were increased to a greater extent in T1DC, while reduced glutathione (GSH) and reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) levels were decreased to a greater extent and adenosine triphosphate (ATP) level was much lower in T1DC versus T2DC. CONCLUSIONS: The results suggest that osmotic damage, GSH loss, and decreased ATP production might be important pathological mechanisms in T1DC formation, whereas crystallin modification and cross-linking/aggregation as well as IF degradation may play more crucial roles in T2DC formation.


Assuntos
Catarata/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Proteínas do Olho/metabolismo , Trifosfato de Adenosina/metabolismo , Aldeído Redutase/metabolismo , Análise de Variância , Animais , Catarata/patologia , Progressão da Doença , Glutationa/metabolismo , Cristalino/metabolismo , Masculino , NADP/metabolismo , Proteoma , Ratos , Ratos Wistar , Sorbitol/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
8.
Phys Med Biol ; 59(8): 1935-46, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24651525

RESUMO

Fiducial markers are used in a wide range of medical imaging applications. In radiation therapy, they are often implanted near tumors and used as motion surrogates that are tracked with fluoroscopy. We propose a novel and robust method based on dynamic programming (DP) for retrospectively localizing radiopaque fiducial markers in fluoroscopic images. Our method was compared to template matching (TM) algorithms on 407 data sets from 24 patients. We found that the performance of TM varied dramatically depending on the template used (ranging from 47% to 92% of data sets with a mean error <1 mm). DP by itself requires no template and performed as well as the best TM method, localizing the markers in 91% of the data sets with a mean error <1 mm. Finally, by combining DP and TM, we were able to localize the markers in 99% of the data sets with a mean error <1 mm, regardless of the template used. Our results show that DP can be a powerful tool for analyzing tumor motion, capable of accurately locating fiducial markers in fluoroscopic images regardless of marker type, shape, and size.


Assuntos
Algoritmos , Marcadores Fiduciais , Fluoroscopia/normas
9.
Int J Radiat Oncol Biol Phys ; 85(4): 999-1005, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23102840

RESUMO

PURPOSE: To evaluate whether planning 4-dimensional computed tomography (4DCT) can adequately represent daily motion of abdominal tumors in regularly fractionated and stereotactic body radiation therapy (SBRT) patients. METHODS AND MATERIALS: Intrafractional tumor motion of 10 patients with abdominal tumors (4 pancreas-fractionated and 6 liver-stereotactic patients) with implanted fiducials was measured based on daily orthogonal fluoroscopic movies over 38 treatment fractions. The needed internal margin for at least 90% of tumor coverage was calculated based on a 95th and fifth percentile of daily 3-dimensional tumor motion. The planning internal margin was generated by fusing 4DCT motion from all phase bins. The disagreement between needed and planning internal margin was analyzed fraction by fraction in 3 motion axes (superior-inferior [SI], anterior-posterior [AP], and left-right [LR]). The 4DCT margin was considered as an overestimation/underestimation of daily motion when disagreement exceeded at least 3 mm in the SI axis and/or 1.2 mm in the AP and LR axes (4DCT image resolution). The underlying reasons for this disagreement were evaluated based on interfractional and intrafractional breathing variation. RESULTS: The 4DCT overestimated daily 3-dimensional motion in 39% of the fractions in 7 of 10 patients and underestimated it in 53% of the fractions in 8 of 10 patients. Median underestimation was 3.9 mm, 3.0 mm, and 1.7 mm in the SI axis, AP axis, and LR axis, respectively. The 4DCT was found to capture irregular deep breaths in 3 of 10 patients, with 4DCT motion larger than mean daily amplitude by 18 to 21 mm. The breathing pattern varied from breath to breath and day to day. The intrafractional variation of amplitude was significantly larger than intrafractional variation (2.7 mm vs 1.3 mm) in the primary motion axis (ie, SI axis). The SBRT patients showed significantly larger intrafractional amplitude variation than fractionated patients (3.0 mm vs 2.1 mm, P<.05). CONCLUSIONS: It may not be appropriate to use 4DCT without monitoring of patient motion on a regular basis for patients with abdominal tumors, especially SBRT patients.


Assuntos
Tomografia Computadorizada Quadridimensional , Neoplasias Hepáticas/diagnóstico por imagem , Movimento , Neoplasias Pancreáticas/diagnóstico por imagem , Planejamento da Radioterapia Assistida por Computador/métodos , Respiração , Fracionamento da Dose de Radiação , Humanos , Neoplasias Hepáticas/radioterapia , Neoplasias Pancreáticas/radioterapia , Estudos Retrospectivos
10.
Int J Radiat Oncol Biol Phys ; 85(3): 854-61, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22717241

RESUMO

PURPOSE: To evaluate respiratory gating accuracy and intrafractional consistency for abdominal cancer patients treated with respiratory gated treatment on a regular linear accelerator system. METHODS AND MATERIALS: Twelve abdominal patients implanted with fiducials were treated with amplitude-based respiratory-gated radiation therapy. On the basis of daily orthogonal fluoroscopy, the operator readjusted the couch position and gating window such that the fiducial was within a setup margin (fiducial-planning target volume [f-PTV]) when RPM indicated "beam-ON." Fifty-five pre- and post-treatment fluoroscopic movie pairs with synchronized respiratory gating signal were recorded. Fiducial motion traces were extracted from the fluoroscopic movies using a template matching algorithm and correlated with f-PTV by registering the digitally reconstructed radiographs with the fluoroscopic movies. Treatment was determined to be "accurate" if 50% of the fiducial area stayed within f-PTV while beam-ON. For movie pairs that lost gating accuracy, a MATLAB program was used to assess whether the gating window was optimized, the external-internal correlation (EIC) changed, or the patient moved between movies. A series of safety margins from 0.5 mm to 3 mm was added to f-PTV for reassessing gating accuracy. RESULTS: A decrease in gating accuracy was observed in 44% of movie pairs from daily fluoroscopic movies of 12 abdominal patients. Three main causes for inaccurate gating were identified as change of global EIC over time (∼43%), suboptimal gating setup (∼37%), and imperfect EIC within movie (∼13%). CONCLUSIONS: Inconsistent respiratory gating accuracy may occur within 1 treatment session even with a daily adjusted gating window. To improve or maintain gating accuracy during treatment, we suggest using at least a 2.5-mm safety margin to account for gating and setup uncertainties.


Assuntos
Neoplasias Abdominais/radioterapia , Técnicas de Imagem de Sincronização Respiratória/normas , Neoplasias Abdominais/diagnóstico por imagem , Algoritmos , Fracionamento da Dose de Radiação , Marcadores Fiduciais , Fluoroscopia/métodos , Humanos , Movimento , Posicionamento do Paciente , Radioterapia Guiada por Imagem/métodos , Radioterapia Guiada por Imagem/normas , Técnicas de Imagem de Sincronização Respiratória/métodos
11.
Rev Sci Instrum ; 81(2): 023702, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20192497

RESUMO

Near-infrared optical imaging holds a promise as a noninvasive technology toward cancer diagnostics and other tissue imaging applications. In recent years, hand-held based imagers are of great interest toward the clinical translation of the technology. However hand-held imagers developed to date are typically designed to obtain surface images and not tomography information due to lack of coregistration facilities. Herein, a recently developed hand-held probe-based optical imager in our Optical Imaging Laboratory has been implemented with novel coregistration facilities toward real-time and tomographic imaging of tissue phantoms. Continuous-wave fluorescence-enhanced optical imaging studies were performed using an intensified charge coupled device camera based imaging system in order to demonstrate the feasibility of automated coregistered imaging of flat phantom surfaces, using a flexible probe that can also contour to curvatures. Three-dimensional fluorescence tomographic reconstructions were also demonstrated using coregistered frequency-domain measurements obtained using the hand-held based optical imager. It was also observed from preliminary studies on cubical phantoms that multiple coregistered scans differentiated deeper targets (approximately 3 cm) from artifacts that were not feasible from a single coregistered scan, demonstrating the possibility of improved target depth detectability in the future.


Assuntos
Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Imagem Molecular/instrumentação , Imagem Molecular/métodos , Fenômenos Ópticos , Automação , Estudos de Viabilidade , Corantes Fluorescentes/química , Imageamento Tridimensional , Imagens de Fantasmas , Fatores de Tempo
12.
Transl Oncol ; 3(1): 16-22, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20165691

RESUMO

Near-infrared (NIR) optical imaging is a noninvasive and nonionizing modality that is emerging as a diagnostic tool for breast cancer. The handheld optical devices developed to date using the NIR technology are predominantly developed for spectroscopic applications. A novel handheld probe-based optical imaging device has been recently developed toward area imaging and tomography applications. The three-dimensional (3D) tomographic imaging capabilities of the device have been demonstrated from previous fluorescence studies on tissue phantoms. In the current work, fluorescence imaging studies are performed on tissue phantoms, in vitro, and in vivo tissue models to demonstrate the fast two-dimensional (2D) surface imaging capabilities of this flexible handheld-based optical imaging device, toward clinical breast imaging studies. Preliminary experiments were performed using target(s) of varying volume (0.23 and 0.45 cm(3)) and depth (1-2 cm), using indocyanine green as the fluorescence contrast agent in liquid phantom, in vitro, and in vivo tissue models. The feasibility of fast 2D surface imaging ( approximately 5 seconds) over large surface areas of 36 cm(2) was demonstrated from various tissue models. The surface images could differentiate the target(s) from the background, allowing a rough estimate of the target's location before extensive 3D tomographic analysis (future studies).

13.
Med Phys ; 35(7): 3354-63, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18697559

RESUMO

Hand-held based optical imaging systems are a recent development towards diagnostic imaging of breast cancer. To date, all the hand-held based optical imagers are used to perform only surface mapping and target localization, but are not capable of demonstrating tomographic imaging. Herein, a novel hand-held probe based optical imager is developed towards three-dimensional (3-D) optical tomography studies. The unique features of this optical imager, which primarily consists of a hand-held probe and an intensified charge coupled device detector, are its ability to; (i) image large tissue areas (5 x 10 sq. cm) in a single scan, (ii) perform simultaneous multiple point illumination and collection, thus reducing the overall imaging time; and (iii) adapt to varying tissue curvatures, from a flexible probe head design. Experimental studies are performed in the frequency domain on large slab phantoms (approximately 650 ml) using fluorescence target(s) under perfect uptake (1:0) contrast ratios, and varying target depths (1-2 cm) and X-Y locations. The effect of implementing simultaneous over sequential multiple point illumination towards 3-D tomography is experimentally demonstrated. The feasibility of 3-D optical tomography studies has been demonstrated for the first time using a hand-held based optical imager. Preliminary fluorescence-enhanced optical tomography studies are able to reconstruct 0.45 ml target(s) located at different target depths (1-2 cm). However, the depth recovery was limited as the actual target depth increased, since only reflectance measurements were acquired. Extensive tomography studies are currently carried out to determine the resolution and performance limits of the imager on flat and curved phantoms.


Assuntos
Fluorescência , Tomografia Óptica/instrumentação , Tomografia Óptica/métodos , Algoritmos , Computadores , Diagnóstico por Imagem , Desenho de Equipamento , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Modelos Estatísticos , Imagens de Fantasmas , Técnica de Subtração , Tomografia Computadorizada por Raios X , Transdutores
14.
J Biomed Opt ; 12(5): 054014, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17994902

RESUMO

Near-infrared optical imaging is an emerging noninvasive technology toward breast cancer diagnosis. The optical imaging systems available to date are limited either by flexibility to image any given breast volume, patient comfort, or instrument portability. Here, a hand-held optical probe is designed and developed, 1. employing a unique measurement scheme of simultaneous multiple point illumination and collection for rapid data acquisition and minimal patient discomfort, and 2. employing a curved probe head such that it allows flexible imaging of tissue curvatures. Simulation studies are carried out on homogeneous slab phantoms (5x10x8 cc) to determine an appropriate source-detector configuration for the probe head. These design features are implemented in the development of the probe, which consisted of six simultaneous illuminating and 165 simultaneous collecting fibers, spaced 0.5 cm apart on a 5x10 sq-cm probe head. Simulation studies on 3-D slab and curved phantoms demonstrate an increase in the total area of predicted fluorescence amplitude and overall signal strength on using simultaneous multiple point sources over a single point source. The probe is designed and developed such that on coupling with a detection system in the future, the hand-held probe based imager can be clinically assessed toward cancer diagnostic imaging.


Assuntos
Tecnologia de Fibra Óptica/instrumentação , Microscopia de Fluorescência/instrumentação , Espectrometria de Fluorescência/instrumentação , Espectrofotometria Infravermelho/instrumentação , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Tecnologia de Fibra Óptica/métodos , Microscopia de Fluorescência/métodos , Miniaturização , Imagens de Fantasmas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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