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PURPOSE: The purpose of this work was to determine the water-equivalent thickness of Superflab bolus material for narrow and broad field-of-view (FOV) x-ray geometries at diagnostic x-ray energies. METHODS: Transmission measurements were performed for incremental thicknesses of Superflab bolus material and water in narrow and broad FOV x-ray geometries. The transmission data was fit to a non-linear model for x-ray transmission - the Archer model. Water-equivalent thickness of Superflab was calculated based upon fitting parameters to transmission curves for 75, 95, and 115 kV x-ray tube voltages. Measured x-ray transmission factors for water and Superflab were used to determine the water equivalence of Superflab. RESULTS: For all x-ray tube voltages and geometries, the water equivalence of Superflab was greater than one, indicating that Superflab is more attenuating than water. This effect was stronger for broad FOV geometries. At 95 kV, 30 cm of Superflab corresponded to 32.0 cm of water in the narrow FOV geometry, and 34.3 cm of water in the broad FOV geometry. The Archer model fitting parameters and Superflab water equivalence are reported for all x-ray beam conditions explored in this work. CONCLUSIONS: Superflab bolus material is more attenuating than water at diagnostic x-ray energies. The Archer model and its respective fitting parameters reported in this work may be used to estimate the water-equivalent thickness of Superflab for diagnostic x-ray spectra.
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Agua , Radiografía , Rayos XRESUMEN
RATIONALE AND OBJECTIVES: The purpose of this study was to develop and evaluate a patient thickness-based protocol specifically for the confirmation of enteric tube placements in bedside abdominal radiographs. Protocol techniques were set to maintain image quality while minimizing patient dose. MATERIALS AND METHODS: A total of 226 pre-intervention radiographs were obtained to serve as a baseline cohort for comparison. After the implementation of a thickness-based protocol, a total of 229 radiographs were obtained as part of an intervention cohort. Radiographs were randomized and graded for diagnostic quality by seven expert radiologists based on a standardized conspicuity scale (grades: 0 non-diagnostic to 3+). Basic patient demographics, body mass index, ventilatory status, and enteric tube type were recorded and subgroup analyses were performed. Effective dose was estimated for both cohorts. RESULTS: The dedicated thickness-based protocol resulted in a significant reduction in effective dose of 80% (p-value < 0.01). There was no significant difference in diagnostic quality between the two cohorts with 209 (92.5%) diagnostic radiographs in the baseline and 221 (96.5%) diagnostic radiographs in the thickness-based protocol (p-value 0.06). CONCLUSION: A protocol optimized for the confirmation of enteric tube placements was developed. This protocol results in lower patient effective dose, without sacrificing diagnostic accuracy. The technique chart is provided for reference. The protocol development process outlined in this work could be readily generalized to other imaging clinical tasks.
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Reducción Gradual de Medicamentos , Radiografía Abdominal , Humanos , Dosis de Radiación , Radiografía , RadiólogosRESUMEN
Venous thromboembolism is a significant source of morbidity and mortality worldwide. Catheter-directed thrombolytics is the primary treatment used to relieve critical obstructions, though its efficacy varies based on the thrombus composition. Non-responsive portions of the specimen often remain in situ, which prohibits mechanistic investigation of lytic resistance or the development of diagnostic indicators for treatment outcomes. In this study, thrombus samples extracted from venous thromboembolism patients were analyzed ex vivo to determine their histological properties, susceptibility to lytic therapy, and imaging characteristics. A wide range of thrombus morphologies were observed, with a dependence on age and etymology of the specimen. Fibrinolytic inhibitors including PAI-1, alpha 2-antiplasmin, and TAFI were present in samples, which may contribute to the response venous thrombi to catheter-directed thrombolytics. Finally, a weak but significant correlation was observed between the response of the sample to lytic drug and its magnetic microstructure assessed with a quantitative MRI sequence. These findings highlight the myriad of changes in venous thrombi that may promote lytic resistance, and imaging metrics that correlate with treatment outcomes.
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Biomarcadores/metabolismo , Diagnóstico por Imagen de Elasticidad/métodos , Activador de Tejido Plasminógeno/administración & dosificación , Ultrasonografía/métodos , Trombosis de la Vena/patología , Fibrinolíticos/administración & dosificación , Humanos , Trombosis de la Vena/tratamiento farmacológico , Trombosis de la Vena/metabolismoRESUMEN
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education and professional practice of medical physics. The AAPM has more than 8,000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: (1) Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. (2) Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances.
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Física Sanitaria , Oncología por Radiación , Humanos , Sociedades , Estados UnidosRESUMEN
We propose a novel framework for determining radiomics feature robustness by considering the effects of both biological and noise signals. This framework is preliminarily tested in a study predicting the epidermal growth factor receptor (EGFR) mutation status in non-small cell lung cancer (NSCLC) patients. Pairs of CT images (baseline, 3-week post therapy) of 46 NSCLC patients with known EGFR mutation status were collected and a FDA-customized anthropomorphic thoracic phantom was scanned on two vendors' scanners at four different tube currents. Delta radiomics features were extracted from the NSCLC patient CTs and reproducible, non-redundant, and informative features were identified. The feature value differences between EGFR mutant and EGFR wildtype patients were quantitatively measured as the biological signal. Similarly, radiomics features were extracted from the phantom CTs. A pairwise comparison between settings resulted in a feature value difference that was quantitatively measured as the noise signal. Biological signals were compared to noise signals at each setting to determine if the distributions were significantly different by two-sample t-test, and thus robust. Four optimal features were selected to predict EGFR mutation status, Tumor-Mass, Sigmoid-Offset-Mean, Gabor-Energy and DWT-Energy, which quantified tumor mass, tumor-parenchyma density transition at boundary, line-like pattern inside tumor and intratumoral heterogeneity, respectively. The first three variables showed robustness across the majority of studied CT acquisition parameters. The textual feature DWT-Energy was less robust. The proposed framework was able to determine robustness of radiomics features at specific settings by comparing biological signal to noise signal. Identification of robust radiomics features may improve the generalizability of radiomics models in future studies.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/genética , Humanos , Pulmón , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/genética , Fantasmas de ImagenRESUMEN
BACKGROUND: We describe our diagnostic sacroiliac joint (SIJ) injection technique under the guidance of three-dimensional cone beam computed tomography (3D-CBCT) fused with real-time fluoroscopy. METHODS: A retrospective review of 17 patients (mean age 55.4 (range 40-74) years) who received a total of 23 diagnostic SIJ injections between March 2016 and November 2017 were performed. Pre- and post-procedure pain scores were reviewed from the medical records and then these findings were correlated with which patients were and were not diagnosed with SIJ pain by clinical management. The final diagnosis of SIJ-related pain was made in cases with at least 50% symptomatic improvement following SIJ-specific pain treatments. RESULTS: Some 87% (n=20/23) of injections achieved more than 50% pain relief after the diagnostic SIJ injection. The final diagnosis of the target SIJ-related pain after follow-up and management was found in 90% (n=18/20) of cases. There were two cases with positive tests diagnosed as non-SIJ pain including one with the diagnosis of femuroacetabular impingement and one with pain related to loosening of knee hardware. The sensitivity, specificity, positive predictive value, and negative predicative value of diagnostic SIJ injections were 100%, 60%, 89%, and 100%, respectively, with a 40% false-positive rate. There were no procedure-related complications. CONCLUSION: 3D-CBCT fused with real-time fluoroscopy for SIJ injection is accurate and safe.
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Manejo del Dolor/métodos , Articulación Sacroiliaca/efectos de los fármacos , Articulación Sacroiliaca/diagnóstico por imagen , Tomografía Computarizada de Haz Cónico Espiral/métodos , Adulto , Anciano , Dipirona/administración & dosificación , Femenino , Fluoroscopía/métodos , Humanos , Inyecciones Intraarticulares/métodos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
PURPOSE: To evaluate the radiation dose differences for intraprocedural computed tomography (CT) imaging between cone-beam CT and angio-CT acquired during transarterial radioembolization (TARE) therapies for hepatocellular carcinoma. MATERIALS AND METHODS: A retrospective cohort of 22 patients who underwent 23 TARE procedures were selected. Patients were imaged in both cone-beam CT and angio-CT rooms as a part of their conventional treatment plan. Effective dose contributions from individual CT acquisitions as well as the cumulative dose contributions from procedural 3D imaging were evaluated. Angiography dose contributions were omitted. Cone-beam CT images were acquired on a C-arm Philips Allura system. Effective doses were evaluated by coupling previously published conversion factors (effective dose per dose-area product) to patient's dose-area product meter readings after the procedure. Angio-CT images were acquired on a hybrid Canon Infinix-i Aquilion PRIME system. Effective doses from angio-CT scans were estimated using Radimetrics. Comparisons of a single patient's dose differential between the 2 technologies were made. RESULTS: The mean effective dose from a single CT scan was 6.42 mSv and 5.99 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .3224), despite the greater field of view and average craniocaudal scan coverage in angio-CT. The mean effective dose summed across all CTs in a procedure was 12.89 mSv and 34.35 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .0018). CONCLUSIONS: The mean effective dose per CT scan is comparable between cone-beam CT and angio-CT when considered in direct comparison for a single patient.
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Carcinoma Hepatocelular/terapia , Angiografía por Tomografía Computarizada , Tomografía Computarizada de Haz Cónico , Embolización Terapéutica , Neoplasias Hepáticas/terapia , Dosis de Radiación , Radiofármacos/administración & dosificación , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/patología , Angiografía por Tomografía Computarizada/efectos adversos , Tomografía Computarizada de Haz Cónico/efectos adversos , Embolización Terapéutica/efectos adversos , Humanos , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/patología , Valor Predictivo de las Pruebas , Radiofármacos/efectos adversos , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del TratamientoRESUMEN
AIMS: To determine whether ginsenoside Rg1 is involved in scratch wound healing through altered expression of related molecules in astrocytes and improved functional recovery after spinal cord injury (SCI). MATERIALS AND METHODS: Astrocytes were isolated from rats, followed by Rg1 treatment. The wound healing test was performed to observe the scratch wound healing in different groups. The expression of nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), basic fibroblast growth factor (bFGF), and components of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway were detected by western blot. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the altered expression of laminin (LN) and fibronectin (FN). A revised Allen's method for the SCI model was performed, followed by Rg1 treatment. Then, functional scoring was conducted to evaluate the functional recovery. Hematoxylin-eosin (HE) staining showed changes in the void area. Finally, western blot assessed the expression of glial fibrillary acidic protein (GFAP) and chondroitin sulfate proteoglycans (CSPGs). KEY FINDINGS: Rg1 mediated scratch wound healing through inducing an increased release of LN, FN, NGF, GDNF, and bFGF in vitro. Additionally, Rg1 activated the PI3K/Akt signaling pathway and promoted the functional recovery of hindlimb movement in rats. Furthermore, Rg1 significantly reduced the void area and downregulated the expression of GFAP and CSPGs. SIGNIFICANCE: Rg1 not only enhanced the scratch wound repair in vitro through the release of astroglial neurotrophic factors, adhesion factors, and inhibitory factors, but it also improved the functional recovery in vivo following SCI.
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Astrocitos/efectos de los fármacos , Ginsenósidos/farmacología , Traumatismos de la Médula Espinal/tratamiento farmacológico , Cicatrización de Heridas/efectos de los fármacos , Animales , Astrocitos/metabolismo , Femenino , Masculino , Factores de Crecimiento Nervioso/metabolismo , Fosfatidilinositol 3-Quinasa/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Sprague-Dawley , Recuperación de la Función , Transducción de Señal/efectos de los fármacos , Traumatismos de la Médula Espinal/fisiopatologíaRESUMEN
BACKGROUND: Default pediatric protocols on many digital radiography systems are configured based on patient age. However, age does not adequately characterize patient size, which is the principal determinant of proper imaging technique. Use of default pediatric protocols by inexperienced technologists can result in patient overexposure, inadequate image quality, or repeated examinations. OBJECTIVE: To ensure diagnostic image quality at a well-managed patient radiation exposure by transitioning to thickness-based protocols for pediatric portable abdomen radiography. MATERIALS AND METHODS: We aggregated patient thickness data, milliamperes (mAs), kilovoltage peak (kVp), exposure index (EI), source-to-detector distance, and grid use for all portable abdomen radiographs performed in our pediatric hospital in a database with a combination of automated and manual data collection techniques. We then analyzed the database and used it as the basis to construct thickness-based protocols with consistent image quality across varying patient thicknesses, as determined by the EI. RESULTS: Retrospective analysis of pediatric portable exams performed at our adult-focused hospitals demonstrated substantial variability in EI relative to our pediatric hospital. Data collection at our pediatric hospital over 4 months accumulated roughly 800 portable abdomen exams, which we used to develop a thickness-based technique chart. CONCLUSION: Through automated retrieval of data in our systems' digital radiography exposure logs and recording of patient abdomen thickness, we successfully developed thickness-based techniques for portable abdomen radiography.
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Abdomen/anatomía & histología , Abdomen/diagnóstico por imagen , Sistemas de Atención de Punto , Radiografía Abdominal/instrumentación , Niño , Protocolos Clínicos , Femenino , Humanos , Masculino , Mejoramiento de la Calidad , Estudios RetrospectivosRESUMEN
The aim of this study was to determine the effects of ginsenoside Rg1 on the migration of olfactory ensheathing cells (OECs) in vitro, and its influence on the therapeutic efficacy of OECs transplanted in vivo for the treatment of spinal cord injury (SCI). Primary cultured and purified OECs (prepared from rats) were treated with ginsenoside Rg1. The wound healing test indicated that ginsenoside Rg1 promoted the migration of OECs. Real-time RT-PCR demonstrated that ginsenoside Rg1 upregulated the expression of migration-related factors of OECs, including matrix metalloproteinases-2 (MMP-2), MMP-9, and neural cell adhesion molecule 1 (NCAM1). Moreover, Western blot analysis indicated that ginsenoside Rg1 significantly promoted the migration of OECs via the phosphatidylinositol 3-kinase (PI3K)/Akt pathway. An SCI rat model was induced in vivo using a revised Allen's method. The Basso, Beattie, and Bresnahan (BBB) scores and histological analysis demonstrated that OECs, which were treated with ginsenoside Rg1, exhibited significant improvement in SCI compared with both the control group and the OEC group. Thus, ginsenoside Rg1 may represent a novel treatment target for SCI.
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Ginsenósidos/farmacología , Neuroglía/efectos de los fármacos , Neuroglía/trasplante , Traumatismos de la Médula Espinal/terapia , Animales , Antígeno CD56/genética , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Femenino , Masculino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Neuroglía/fisiología , Fosfatidilinositol 3-Quinasa/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Transducción de Señal , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Artifacts are frequently encountered at clinical US, and while some are unwanted, others may reveal valuable information related to the structure and composition of the underlying tissue. They are essential in making ultrasonography (US) a clinically useful imaging modality but also can lead to errors in image interpretation and can obscure diagnoses. Many of these artifacts can be understood as deviations from the assumptions made in generating the image. Therefore, understanding the physical basis of US image formation is critical to understanding US artifacts and thus proper image interpretation. This review is limited to gray-scale artifacts and is organized into discussions of beam- and resolution-related, location-related (ie, path and speed), and attenuation-related artifacts. Specifically, artifacts discussed include those related to physical mechanisms of spatial resolution, speckle, secondary lobes, reflection and reverberation, refraction, speed of sound, and attenuation. The underlying physical mechanisms and appearances are discussed, followed by real-world strategies to mitigate or accentuate these artifacts, depending on the clinical application. Relatively new US modes, such as spatial compounding, tissue harmonic imaging, and speckle reduction imaging, are now often standard in many imaging protocols; the effects of these modes on US artifacts are discussed. The ability of a radiologist to understand the fundamental physics of ultrasound, recognize common US artifacts, and provide recommendations for altering the imaging technique is essential for proper image interpretation, troubleshooting, and utilization of the full potential of this modality. ©RSNA, 2017.
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Artefactos , Ultrasonografía/métodos , Humanos , FísicaRESUMEN
Reject rate analysis has been part of radiography departments' quality control since the days of screen-film radiography. In the era of digital radiography, one might expect that reject rate analysis is easily facilitated because of readily available information produced by the modality during the examination procedure. Unfortunately, this is not always the case. The lack of an industry standard and the wide variety of system log entries and formats have made it difficult to implement a robust multivendor reject analysis program, and logs do not always include all relevant information. The increased use of digital detectors exacerbates this problem because of higher reject rates associated with digital radiography compared with computed radiography. In this article, the authors report on the development of a unified database for vendor-neutral reject analysis across multiple sites within an academic institution and share their experience from a team-based approach to reduce reject rates.
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Sistemas de Administración de Bases de Datos/organización & administración , Bases de Datos Factuales , Diagnóstico por Imagen , Registros Electrónicos de Salud/organización & administración , Registro Médico Coordinado/métodos , Sistemas de Información Radiológica/organización & administración , Procedimientos Innecesarios , Errores Diagnósticos/prevención & control , Errores Diagnósticos/estadística & datos numéricos , Almacenamiento y Recuperación de la Información/métodos , Integración de SistemasRESUMEN
INTRODUCTION: Whitlow is a common disease in clinic, characterized by pain and swelling of finger. However, few articles had reported on extensive infection in the forearm caused by whitlow infected by mycobacterium tuberculosis (MTB). PATIENT CONCERNS: A 70-year-old Chinese female complained of fester in back of left hand for 5 days. She had a history of recurrent whitlow for 14 months and pulmonary tuberculosis (TB). She received treatment in another hospital due to whitlow on July 2016. Then she was treated with incision and drainage. However, whitlow presented again several times before coming to our hospital. She came to our hospital on September 7, 2017 and x-ray of forearm showed that radius, ulna, and carpal were eroded. DIAGNOSES: She was diagnosed with left extensive infection in the forearm caused by whitlow infection by MTB. INTERVENTIONS: Considering her serious and extensive condition, we performed left forearm amputation on September 12, 2017. We collected some soft tissue cut down during surgery and conducted pathological examination. Finally, pathological result showed MTB infection. Then that patient was treated with antituberculosis therapy. OUTCOMES: Up to now, illness condition has not progressed. A recent x-ray of forearm showed no osteolysis in humerus. CONCLUSIONS: Extensive infection in the forearm after recurrent whitlow infection by MTB is rare. So when we face recurrent whitlow, a rapid diagnosis and treatment are required to prevent complications. This case reminds us that recurrent whitlow is dangerous. Attention must be paid to recurrent whitlow. If necessary, amputation should be considered.
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Antebrazo , Dermatosis de la Mano/diagnóstico , Tuberculosis Cutánea/diagnóstico , Tuberculosis/diagnóstico , Anciano , Antituberculosos/uso terapéutico , Femenino , Dedos , Antebrazo/diagnóstico por imagen , Antebrazo/patología , Antebrazo/cirugía , Dermatosis de la Mano/tratamiento farmacológico , Humanos , Tuberculosis/tratamiento farmacológico , Tuberculosis/patología , Tuberculosis Cutánea/tratamiento farmacológicoRESUMEN
The past decade has seen a significant growth in diagnostic CT imaging as a direct result of the clinical value provided by CT imaging. At the same time, many new techniques and resources are now available to make CT imaging safe. This article presents the basics of CT dosimetry and their usage in clinical practices, methods to implement CT dose reduction, followed by a summary of legislation, and guidelines related to patient safety in diagnostic CT imaging. Also, CT radiation dose diagnostic reference levels from published regional and national surveys are reviewed and applied in a CT dose tracking and monitoring program.
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Seguridad del Paciente , Traumatismos por Radiación/prevención & control , Monitoreo de Radiación/métodos , Tomografía Computarizada por Rayos X/efectos adversos , Humanos , Dosis de RadiaciónRESUMEN
OBJECTIVE: To determine whether apoptosis is induced in rat hepatic stellate cells (HSCs) in response to activation of the hepatocyte growth factor (HGF) by hepatocyte growth factor activator (HGFA) by using a co-culture system of bone marrow mesenchymal stem cells (BMSCs) and HSCs. METHODS: In this study, cells were divided into the following five groups: HSC control group: HSCs co-cultured with fibroblast cells; HSCs blank group: HSCs cultured alone; BMSCs blank group: BMSCs cultured alone; Experimental group: BMSCs + HSCs; HGFA intervention group: HSCs treated with 70 ng/mL of HGFA. The culture systems were established in culture plates with transwell inserts, and cells were assessed at 24, 48, and 72 h of growth. Dynamic changes in cell morphology were observed under an inverted phase contrast microscope. The surface markers of BMSCs and the apoptosis rate of HSCs were detected by Annexin-V-FITC/propidium iodide (PI). Expression of a-smooth muscle actin (SMA) in HSCs was evaluated by immunohistochemistry. The presence of activated HGF (HGF-a chain) was determined by immunofluorescent staining. HSC proliferation was measured by MTT assay, and the concentrations of HGF and HGFA were quantified by enzyme-linked immunosorbent assay (ELISA). RESULTS: MTT results indicated that treatment with HGF alone had no effect on HSC proliferation rate (vs. HSC blank group, P more than 0.05), but that 24 h treatment with HGFA significantly inhibited the proliferation rate (0.26 ± 0.00 vs. blank group: 0.13 ± 0.04, P = 0.02); moreover, this effect was concentration-dependent. Expression of HGF-a was lower in the experimental group than in the HGFA intervention group at 72 h (37.24 ± 1.03 vs. 40.44 ± 0.77, P = 0.04), and both of these groups had higher expression than the control group at all time points examined (P less than 0.05). The apoptosis rate was consistently higher in the experimental group than in the HGFA intervention group, but most robustly at 72 h (40.77 ± 1.16% vs. 33.35 ± 2.04%, P = 0.00); moreover, the apoptosis rate was significantly higher than that in the control group at all time points examined (P less than 0.01). The concentration of HGF in the experimental group and the HGFA intervention group showed a time-dependent reduction, and was consistently lower than that in the HSCs control group (P less than 0.05). Finally, the concentration of HGFA was higher in the experimental group than in the blank group at all time points examined (P less than 0.05). CONCLUSION: The BMSC-HSC co-culture system can promote secretion of HGFA from HSCs and HGF activation, thereby inducing apoptosis of HSCs.
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Apoptosis , Células Estrelladas Hepáticas/citología , Factor de Crecimiento de Hepatocito/metabolismo , Animales , Apoptosis/efectos de los fármacos , Células de la Médula Ósea/citología , Células Cultivadas , Técnicas de Cocultivo , Factor de Crecimiento de Hepatocito/farmacología , Masculino , Células Madre Mesenquimatosas/citología , Ratas , Ratas Sprague-Dawley , Serina Endopeptidasas/metabolismoRESUMEN
OBJECTIVE: Radiation exposure from CT studies has increased over the past 30 years in the United States and now constitutes approximately 50% of the radiation dose index administered in the health care setting. Tracking CT dose index (CTDI) is cumbersome because it relies on a manufacturer-generated screen capture, which contains the estimated dose index exposure for the patient. The radiation dose index information is not digital but, rather, is "burned" into the image (i.e., not in numeric form, not as part of the image header or elsewhere associated with the study), making it difficult to automatically share these data with other information systems. The purpose of the dose index reporting application (DIRA) we developed for CT is to extract the radiation dose index information from the CTDI reports to eventually perform automated quality control, promote radiation safety awareness, and provide a longitudinal record of patient-specific health care-related radiation exposure. MATERIALS AND METHODS: A random selection of 518 CTDI reports were processed by the DIRA and the dose index information was extracted. CTDI reports using a standard DICOM C-STORE to the DIRA allow an automated process to compile radiation dose index and patient information in a Web-based framework using a structured query language (SQL) database. RESULTS: Our initial tests showed that the DIRA accurately extracted dose index information from 518 of 518 CTDI reports (100%). Because the extracted CTDI descriptor-dose-length product-is based on standard CTDI measurements obtained using fixed-size cylindric polymethylmethacrylate phantoms, preliminary studies have been performed to correct for patient size by applying correction factors derived from CTDI measurements using a range of phantom sizes from 6 to 32 cm in diameter. Our system provides a way to automatically track CTDI on existing CT scanners and does not rely on the DICOM SR Dose Index Report standard, which is available on only the newest CT scanners. CONCLUSION: A modular and vendor-independent DIRA system can be integrated with any existing CT scanner. This system greatly facilitates digital dose index reporting and makes it possible to provide a longitudinal record of the health care radiation exposure estimate in an individual patient's health record.
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Automatización , Dosis de Radiación , Radiometría/métodos , Tomografía Computarizada por Rayos X , Humanos , Internet , Fantasmas de Imagen , Programas Informáticos , Tomógrafos Computarizados por Rayos X , Estados UnidosRESUMEN
OBJECTIVE: To evaluate the efficacy of posterior instrumentation plus vertebroplasty and posterolateral fusion using calcium sulfate for thoracolumbar burst fractures without neurologic deficits. METHODS: Between July 2005 and January 2008, a total of 45 patients who had been diagnosed as having thoracolumbar burst fractures without neurologic deficits were treated with pedicle screw instrumentation plus vertebroplasty using calcium sulfate in our unit. The Cobb angles and loss rates of anterior-middle columns height at different time intervals were measured on lateral radiographs, and the preoperative and postoperative functional outcomes were evaluated using the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI). RESULTS: The Cobb angles and loss rates of anterior-middle columns height postoperatively period were restored significantly compared with those noted preoperatively. The angles and heights were well maintained for at least two years using this technique. The mean postoperative VAS (back pain) score was 2.1 ± 0.8, which was significantly better (P < 0.001) than the mean preoperative VAS score 7.9 ± 1.1. The average preoperative ODI was 66.6 ± 8.1% and this had improved significantly to 15.5 ± 4.5% by the latest follow-up (P < 0.001). No instrumentation failure was detected in this study. The calcium sulfate had been absorbed completely by 3-6 months postoperatively. CONCLUSION: Pedicle screw instrumentation plus augmentation vertebroplasty with calcium sulfate is an economic, efficient and reliable technique for treating unstable thoracolumbar fractures without neurologic deficits.
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Fijación Interna de Fracturas/métodos , Vértebras Lumbares/lesiones , Fracturas de la Columna Vertebral/cirugía , Vértebras Torácicas/lesiones , Vertebroplastia/métodos , Adulto , Cementos para Huesos/uso terapéutico , Tornillos Óseos , Sulfato de Calcio/uso terapéutico , Evaluación de la Discapacidad , Estudios de Factibilidad , Femenino , Fijación Interna de Fracturas/instrumentación , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/cirugía , Masculino , Persona de Mediana Edad , Dimensión del Dolor/métodos , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fusión Vertebral/métodos , Vértebras Torácicas/diagnóstico por imagen , Vértebras Torácicas/cirugía , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
BACKGROUND/AIMS: In Gamma Knife radiosurgery, T(1) MRI is most commonly used and is generally sufficient for targeting the trigeminal nerve. For patients whose trigeminal nerves are unclear on T(1) MRI, FIESTA MRI supplements anatomical structure visualization and may improve trigeminal nerve delineation. The purpose of this study was to develop a registration strategy for T(1) and FIESTA MRIs. METHODS: We conducted a retrospective study on 54 trigeminal neuralgia patients. All patients were scanned with T(1) and FIESTA MRIs. We evaluated 4 methods of registration: automatic image definition, superior-slice definition, middle-slice definition and inferior-slice definition. Target discrepancies were measured by deviations from an intracranial landmark on T(1) and FIESTA MR images. RESULTS: The overall range in registration error was 0.10-5.19 mm using superior-, 0.10-1.56 mm using middle- and 0.14-2.89 mm using inferior-slice definition. Registration error >2 mm was observed in 11% of the patients using superior-, 4% using middle- and 7% using inferior-slice FIESTA MRI definition. CONCLUSIONS: Among patients for whom FIESTA and T(1) MRI are used, registration based on middle-slice definition reduces registration error and improves targeting of the trigeminal nerve.
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Imagen por Resonancia Magnética/métodos , Radiocirugia/métodos , Nervio Trigémino/cirugía , Neuralgia del Trigémino/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Radiocirugia/instrumentación , Estudios RetrospectivosRESUMEN
Transplantation of olfactory ensheathing cells (OECs) is currently considered to be one of the most promising repair strategies for human spinal cord injury. However, the factors that regulate OECs are still poorly understood. Ginsenoside Rg1 (Rg1), the phytosterol from Panax ginseng, is a potent neuroprotective agent that promotes axonal regeneration. The aim of this study is to determine whether Rg1 would influence the biological activity of OECs. Primary cultured OECs from the olfactory bulb of neonatal rats were treated with Rg1 of various concentrations and durations. Using MTT and bromodeoxyuridine assays, we found that Rg1 significantly promoted cell proliferation, with an optimal concentration of 40 mug/ml of Rg1 at 72 h. In addition, RT-PCR and ELISA assays showed that Rg1 could upregulate the mRNA expression and secretion of glial cell-derived neurotrophic factor, brain-derived neurotrophic factor, and nerve growth factor. These results suggest that Rg1 may have a great potential in OEC therapy.
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Ginsenósidos/farmacología , Factores de Crecimiento Nervioso/efectos de los fármacos , Regeneración Nerviosa/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Vías Olfatorias/citología , Vías Olfatorias/efectos de los fármacos , Panax/química , Traumatismos de la Médula Espinal/terapia , Animales , Secuencia de Bases , Factor Neurotrófico Derivado del Encéfalo/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ginsenósidos/química , Ginsenósidos/aislamiento & purificación , Estructura Molecular , Factores de Crecimiento Nervioso/metabolismo , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/aislamiento & purificación , RatasRESUMEN
PURPOSE: To investigate the use of advanced ultrasonic imaging to quantitatively evaluate normal-tissue toxicity in breast-cancer radiation treatment. METHODS AND MATERIALS: Eighteen breast cancer patients who received radiation treatment were enrolled in an institutional review board-approved clinical study. Radiotherapy involved a radiation dose of 50.0 to 50.4 Gy delivered to the entire breast, followed by an electron boost of 10.0 to 16.0 Gy delivered to the tumor bed. Patients underwent scanning with ultrasound during follow-up, which ranged from 6 to 94 months (median, 22 months) postradiotherapy. Conventional ultrasound images and radio-frequency (RF) echo signals were acquired from treated and untreated breasts. Three ultrasound parameters, namely, skin thickness, Pearson coefficient, and spectral midband fit, were computed from RF signals to measure radiation-induced changes in dermis, hypodermis, and subcutaneous tissue, respectively. Ultrasound parameter values of the treated breast were compared with those of the untreated breast. Ultrasound findings were compared with clinical assessment using Radiation Therapy Oncology Group (RTOG) late-toxicity scores. RESULTS: Significant changes were observed in ultrasonic parameter values of the treated vs. untreated breasts. Average skin thickness increased by 27.3%, from 2.05 ± 0.22 mm to 2.61 ± 0.52 mm; Pearson coefficient decreased by 31.7%, from 0.41 ± 0.07 to 0.28 ± 0.05; and midband fit increased by 94.6%, from -0.92 ± 7.35 dB to 0.87 ± 6.70 dB. Ultrasound evaluations were consistent with RTOG scores. CONCLUSIONS: Quantitative ultrasound provides a noninvasive, objective means of assessing radiation-induced changes to the skin and subcutaneous tissue. This imaging tool will become increasingly valuable as we continue to improve radiation therapy technique.