RESUMEN
PURPOSE: To determine inter-scan, inter-reader and intra-reader variability of trabecular structure analysis using flat-panel volume computed tomography (fp-VCT) in cadaver knee specimens. METHODS: Five explanted knee specimens were imaged at three different time points using fp-VCT. Four parameters that quantify trabecular bone structure of the proximal tibia were measured by two observers at two different time points. Bland-Altman analysis was used to compute the inter-scan, inter-observer and intra-observer variability. RESULTS: Inter-scan variability was low, with a mean difference of 0% and a standard deviation less than 8.4% for each of the four parameters. The inter-observer and intra-observer variability was less than 2.8% +/- 8.5%. CONCLUSION: Fp-VCT is a method for assessing trabecular structure parameters with low inter-scan, inter-reader and intra-reader variability.
Asunto(s)
Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Sistemas de Información Radiológica , Tibia/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Humanos , Aumento de la Imagen/instrumentación , Aumento de la Imagen/métodos , Imagenología Tridimensional/instrumentación , Técnicas In Vitro , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/instrumentaciónRESUMEN
Flat-panel volume computed tomography (CT) systems have an innovative design that allows coverage of a large volume per rotation, fluoroscopic and dynamic imaging, and high spatial resolution that permits visualization of complex human anatomy such as fine temporal bone structures and trabecular bone architecture. In simple terms, flat-panel volume CT scanners can be thought of as conventional multidetector CT scanners in which the detector rows have been replaced by an area detector. The flat-panel detector has wide z-axis coverage that enables imaging of entire organs in one axial acquisition. Its fluoroscopic and angiographic capabilities are useful for intraoperative and vascular applications. Furthermore, the high-volume coverage and continuous rotation of the detector may enable depiction of dynamic processes such as coronary blood flow and whole-brain perfusion. Other applications in which flat-panel volume CT may play a role include small-animal imaging, nondestructive testing in animal survival surgeries, and tissue-engineering experiments. Such versatility has led some to predict that flat-panel volume CT will gain importance in interventional and intraoperative applications, especially in specialties such as cardiac imaging, interventional neuroradiology, orthopedics, and otolaryngology. However, the contrast resolution of flat-panel volume CT is slightly inferior to that of multidetector CT, a higher radiation dose is needed to achieve a comparable signal-to-noise ratio, and a slower scintillator results in a longer scanning time.
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Imagenología Tridimensional/instrumentación , Imagenología Tridimensional/métodos , Tomografía Computarizada por Rayos X/instrumentación , Tomografía Computarizada por Rayos X/métodos , Pantallas Intensificadoras de Rayos X , Diseño de Equipo , Análisis de Falla de Equipo , Evaluación de la Tecnología BiomédicaRESUMEN
OBJECTIVE: A systematic approach to the consideration of various factors on outcome demands a comprehensive grading system for patients with intracranial aneurysms. We have previously identified potential patient- and lesion-specific factors that correlate strongly with outcome after treatment for intracranial aneurysms, and we have developed a comprehensive grading system based on these factors. In this study, we evaluate this grading system in a large series of aneurysm patients treated by surgery and endovascular therapy. METHODS: Between January 1998 and January 2003, ruptured and unruptured aneurysm patients were prospectively entered into a database. Based on our previous study that showed which factors correlated strongly with outcome, data were collected on patient age, aneurysm size, Hunt and Hess grade, and Fisher scale (if presenting with subarachnoid hemorrhage), and a Massachusetts General Hospital grade was then applied. The modified Glasgow Outcome Scale was used for clinical assessment at follow-up, and a binary analysis classified patients into favorable versus unfavorable outcome. Univariate and multivariate analyses for the predictor variables were performed. RESULTS: One thousand forty-nine aneurysms in 914 patients were identified. Fifty-eight percent (n = 608) of the lesions were unruptured, and 25% (n = 261) were treated endovascularly. For patients treated either surgically or endovascularly, worsening outcome was demonstrated for higher Hunt and Hess grade (surgery, P < 0.001; endovascular, P < 0.001), Fisher scale (surgery, P < 0.001; endovascular, P < 0.001) and for older patients (surgery, P < 0.001; endovascular, P = 0.004). Size of aneurysm had a significant effect on outcome after surgery (P = 0.04), but not after endovascular therapy (P = 0.3). Overall, there was a greater proportion of favorable outcomes for anterior circulation compared with posterior circulation lesions (P < 0.0001). For both the surgical and endovascular subgroups, MGH grade correlated well with clinical outcomes. CONCLUSION: The MGH grade is a comprehensive grading system that is easily applied and that allows separation of patients with aneurysms into groups with markedly different outcomes. This information can potentially be helpful in making treatment decisions and when discussing projected outcome before surgical or endovascular intervention of both unruptured and ruptured aneurysms.
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Escala de Consecuencias de Glasgow , Aneurisma Intracraneal/clasificación , Aneurisma Intracraneal/cirugía , Procedimientos Neuroquirúrgicos/métodos , Evaluación de Resultado en la Atención de Salud/métodos , Procedimientos Quirúrgicos Vasculares/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Aneurisma Intracraneal/diagnóstico , Masculino , Persona de Mediana Edad , Pronóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad , Resultado del TratamientoRESUMEN
OBJECTIVE AND IMPORTANCE: The coexistence of spinal arteriovenous malformation (AVM) with congenital abnormalities is relatively common. However, the association of a spinal AVM and lipoma is rare. We present an adult patient with this combined anomaly and discuss the clinical relevance of this case. CLINICAL PRESENTATION: A 42-year-old Caucasian man with progressive paraparesis initially underwent surgery for a tethered spinal cord. Postoperatively, he became paraplegic. He improved gradually over an interval of 8 months and, at that point, worsened again. Subsequent angiographic study revealed a spinal dural arteriovenous fistula located at S1-S2. Additionally, an occipital dural AVM was discovered near the transverse sinus. INTERVENTION: The spinal arteriovenous fistula was excised along with the sacral lipoma. The occipital arteriovenous fistula was embolized successfully at a later time. CONCLUSION: The patient had immediate improvement in sensory symptoms after surgery. At a 9 month follow-up examination, he had regained the ability to walk with crutches, but his bladder dysfunction persisted. Recognition of co-existing vascular anomalies, such as spinal AVMs, is important in patients with tethered cords. The mechanisms involved in this patient's worsening neurological condition after release of the tethered cord are discussed.
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Fístula Arteriovenosa/complicaciones , Laminectomía/efectos adversos , Lipoma/complicaciones , Paraplejía/etiología , Enfermedades de la Médula Espinal/complicaciones , Neoplasias de la Médula Espinal/complicaciones , Adulto , Fístula Arteriovenosa/patología , Fístula Arteriovenosa/cirugía , Angiografía Cerebral/métodos , Humanos , Lipoma/cirugía , Imagen por Resonancia Magnética/métodos , Masculino , Enfermedades de la Médula Espinal/cirugía , Neoplasias de la Médula Espinal/cirugíaRESUMEN
Reflectance confocal microscopy (RCM) allows non-invasive visualization of human skin in vivo. It has been used to describe the histopathological features of acute contact dermatitis (CD). This work was designed to investigate the kinetics of both allergic and irritant CD (ACD and ICD) in vivo. Eighteen subjects with a prior diagnosis of ACD were patch tested with the specific allergen sodium lauryl sulfate as an irritant, and appropriate controls. RCM, transepidermal water loss (TEWL), and fluorescence excitation spectroscopy (FES) were performed at several time points within 2 wk after patch removal. After removal of the Finn chambers at 48 h, superficial epidermal changes, primarily involving the stratum corneum, and increased epidermal thickness were mainly present in ICD. ACD, on the other hand, showed microvesicle formation peaking at 96 h following patch removal. Both ACD and ICD showed exocytosis and similar degrees of spongiosis on RCM. TEWL and FES demonstrated a significant difference between ACD and ICD. RCM, TEWL, and FES are valuable non-invasive tools to quantitatively study the kinetics of the pathophysiology of acute CD reactions in vivo and monitor the changes at a cellular level.
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Dermatitis Alérgica por Contacto/patología , Dermatitis Irritante/patología , Microscopía Confocal/métodos , Adulto , Anciano , Humanos , Persona de Mediana Edad , Pruebas del Parche , Índice de Severidad de la Enfermedad , Piel/inmunología , Piel/metabolismo , Piel/patología , Agua/metabolismoRESUMEN
OBJECTIVE: At many centers, patients undergo both computed tomographic angiography (CTA) and digital subtraction angiography (DSA). This practice negates most of the advantages of CTA, and it renders the risks and disadvantages of the two techniques additive. Previous reports in the literature have assessed the sensitivity and specificity of CTA compared with DSA; however, these investigations have not analyzed the clinical implications of a protocol that replaces DSA with CTA as the only diagnostic and pretreatment planning study for patients with cerebral aneurysms. METHODS: Since late 2001/early 2002, the combined neurovascular unit of the Massachusetts General Hospital has adopted a prospective protocol of CTA in place of DSA as the only diagnostic and pretreatment planning study for patients with cerebral aneurysms (ruptured and unruptured). We report the results obtained during the 12-month period from January 2002 to January 2003. RESULTS: During the study period, 223 patients with cerebral aneurysms underwent initial diagnostic evaluation for cerebral aneurysm by the combined neurovascular team of Massachusetts General Hospital. Of the 223 patients, 109 patients had confirmed subarachnoid hemorrhage (Group A) and 114 patients did not have SAH (Group B). All of these patients were included in the prospective CTA protocol. Cerebral aneurysm treatment was initiated on the basis of CTA alone in 93 Group A patients (86%), in 89 Group B patients (78%), and in 182 patients (82%) overall. Treatment consisted of surgical clipping in 152 patients (68%), endovascular coiling in 56 patients (25%), endovascular parent artery balloon occlusion in 4 patients (2%), and external carotid artery to internal carotid artery bypass and carotid artery surgical occlusion in 2 patients (1%). Nine patients (4%) did not undergo treatment. The cerebral aneurysm detection rate by CTA was 100% for the presenting aneurysm (ruptured aneurysm in Group A or symptomatic/presenting aneurysm in Group B) in both groups. The detection rate by CTA for total cerebral aneurysms, including incidental multiple aneurysms, was 95.3% in Group A, 98.3% in Group B, and 97% overall. The overall morbidity associated with DSA (pretreatment or as intraoperative or postoperative clip evaluation) was one patient (1.3%) with a minor nonneurological complication, one patient (1.3%) with a minor neurological complication, and no patients (0%) with a major neurological complication. CONCLUSION: We have demonstrated promising results with a prospective protocol of CTA in place of DSA as the only diagnostic and pretreatment planning study for patients with ruptured and unruptured cerebral aneurysms. It seems safe and effective to make decisions regarding treatment on the basis of CTA, without performing DSA, in the majority of patients with ruptured and unruptured cerebral aneurysms.