RESUMEN
AIM: To assess the effect of cine frame rate on the accuracy of the detection of pulmonary nodules at computed tomography (CT). MATERIALS AND METHODS: CT images of 15 consecutive patients with (n = 13) or without (n = 2) pulmonary metastases were identified. Initial assessment by two thoracic radiologists provided the "actual" or reference reading. Subsequently, 10 radiologists [board certified radiologists (n = 4) or radiology residents (n = 6)] used different fixed cine frame rates for nodule detection. Within-subjects analysis of variance (ANOVA) was used to evaluate the data. RESULTS: Eighty-nine nodules were identified by the thoracic radiologists (median 8, range 0-29 per patient; median diameter 9 mm, range 4-40 mm). There was a non-statistically significant trend to reduced accuracy at higher frame rates (p=0.113) with no statistically significant difference between experienced observers and residents (p = 0.79). CONCLUSION: The accuracy of pulmonary nodule detection at higher cine frame rates is reduced, unrelated to observer experience.
Asunto(s)
Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/secundario , Tomografía Computarizada por Rayos X/métodos , Competencia Clínica , Reacciones Falso Positivas , Humanos , Variaciones Dependientes del Observador , Estudios ProspectivosRESUMEN
Extracranial carotid occlusive disease can be evaluated with either intravenous (IV) digital subtraction angiography (DSA) or standard angiography. In a prospective study, complications related to 500 IV DSA examinations occurred in 16.6% of patients, including local complications in 2.0%, systemic complications in 15.0%, and neurologic complications in 3.0%. A permanent neurologic deficit occurred in one patient. Complications related to 150 standard angiograms occurred in 7.3% of patients, including local complications in 4.0%, systemic complications in 3.4%, and neurologic complications in 0.7%. There were no permanent neurologic deficits. Serious systemic and neurologic complications occurred in 8.2% of patients during IV DSA and 2.7% of patients during standard angiography. The rapid injection of high volumes of hypertonic contrast media during IV DSA and the resultant hemodynamic and cardiac electrophysiologic changes account for the higher incidence of complications with IV DSA.
Asunto(s)
Angiografía/efectos adversos , Adolescente , Adulto , Anciano , Arteriopatías Oclusivas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Niño , Femenino , Humanos , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Técnica de SustracciónRESUMEN
The authors' experience using the Debrun detachable balloon catheter system in occluding surgically-created carotid-jugular fistulas is described. Useful technical points in preparing and using the system are outlined. Technical failures were encountered both in creation of the fistula model and in use of the system, and their occurrence is documented. It is concluded that, when familiarization with the system's operation is attained, the detachable balloon catheter system promises to offer a valuable method of treatment of traumatic carotid-cavernous fistulas in humans.
Asunto(s)
Fístula Arteriovenosa/terapia , Arterias Carótidas , Cateterismo/métodos , Embolización Terapéutica/métodos , Venas Yugulares , Animales , Fístula Arteriovenosa/diagnóstico por imagen , Arterias Carótidas/diagnóstico por imagen , Cateterismo/instrumentación , Medios de Contraste , Perros , Venas Yugulares/diagnóstico por imagen , RadiografíaRESUMEN
Vertebral artery injury may occur at the time of cervical fracture or dislocation. Congenital vertebral artery variations, especially a double vertebral artery origin, may be responsible for angiographic findings that mimic vertebral artery dissection. Two cases of cervical spine fracture with ipsilateral double vertebral artery are presented. Conventional cerebral angiography is the easiest and best way to make this diagnosis and to exclude vertebral artery dissection.
Asunto(s)
Disección Aórtica/diagnóstico por imagen , Arteria Vertebral/anomalías , Adulto , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Tomografía Computarizada por Rayos X , Arteria Vertebral/diagnóstico por imagen , Arteria Vertebral/lesionesRESUMEN
The hyperdense middle cerebral artery sign is a CT predictor of the development of a large cerebral infarct. The limits of detectability were tested in a blinded, then unblinded analysis of CT scans from 25 acute stroke patients. In the initial blinded analysis, sign detection exhibited the following mean values: sensitivity, 78.5%; specificity, 93.4%; positive predictive value, 66%; negative predictive value, 96.4%; accuracy, 91.3%. Kappa statistics analysis indicated poor interobserver agreement (k = .38). Results of unblinded analysis were as follows: sensitivity, 69%; specificity, 94.4%; positive predictive value, 82.8%; negative predictive value, 88.7%; accuracy, 87.3%. There was fair unblinded interobserver agreement (k = .53). Unblinded analysis had a lower false-positive frequency and did not increase the number of true-positive determinations. We conclude that detection of the hyperdense middle cerebral artery sign on CT scans by multiple observers is a sensitive, accurate, and predictive indicator of middle cerebral artery thromboembolism.
Asunto(s)
Enfermedades Arteriales Cerebrales/diagnóstico por imagen , Embolia y Trombosis Intracraneal/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Enfermedad Aguda , Reacciones Falso Positivas , Femenino , Humanos , Masculino , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Proyectos de InvestigaciónRESUMEN
The characteristics of various types of collimators have been studied systematically for the EMI Mark I brain scanner. The degree of collimation ranged from the 13-mm adjacent A and B slices to 3-mm separated slices. Multiple phantom studies (including variable density immiscible liquid interfaces) have been performed to evaluate the effect of collimation on (a) the line-spread function, (b) the change in effective absorption number, and (c) volume averaging. Effects associated with the technique settings involving the kVp, the mA, and the scan time were also investigated. The results of TLD dose measurements as a function of collimation are presented. The significance of collimation in specific clinical studies involving small, fairly well-circumscribed lesions is discussed.
Asunto(s)
Encefalopatías/diagnóstico por imagen , Tomografía Computarizada por Rayos X/instrumentación , Estudios de Evaluación como Asunto , Humanos , Modelos Estructurales , Dosimetría TermoluminiscenteRESUMEN
Using seven illustrative cases, the authors discuss the computerized tomographic (CT) appearance of cranial epidermoid tumors. These tumors are of low density (-2 to +10 EMI units), seldom show calcification, and do not enhance with contrast medium. Their differentiation from dermoid tumors and craniopharyngiomas is also discussed.
Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Quiste Epidérmico/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Encéfalo/diagnóstico por imagen , Quiste Dermoide/diagnóstico por imagen , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
A case of iatrogenic carotid-cavernous fistula secondary to a Fogarty catheter thrombectomy is presented. The literature and seven previously reported cases are reviewed.
Asunto(s)
Fístula Arteriovenosa/etiología , Enfermedades de las Arterias Carótidas/etiología , Trombosis de las Arterias Carótidas/cirugía , Cateterismo/efectos adversos , Seno Cavernoso , Endarterectomía/efectos adversos , Fístula Arteriovenosa/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/cirugía , Humanos , Enfermedad Iatrogénica , Masculino , Persona de Mediana Edad , RadiografíaRESUMEN
Demonstration of traumatic lumbosacral root avulsion is a rare clinical entity because the bony pelvis offers support and protection to the nerve roots against stretching and rupture. Major vehicular trauma producing unstable pelvic fractures allows lumbosacral root avulsion to occur, and the 18th well-documented case is reported. Delay in diagnosis of several months is common. Demonstration of traumatic meningoceles is important, and metrizamide offers better visualization of the root than does iodophendylate. Absence of the root in the meningocele is equated with avulsion.
Asunto(s)
Fracturas Óseas/complicaciones , Plexo Lumbosacro/lesiones , Meningocele/diagnóstico por imagen , Metrizamida , Huesos Pélvicos/lesiones , Adulto , Femenino , Humanos , Meningocele/etiología , Mielografía , Factores de TiempoAsunto(s)
Enfermedades del Sistema Nervioso Central/diagnóstico por imagen , Leucemia/diagnóstico por imagen , Linfoma/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Encéfalo/diagnóstico por imagen , Neoplasias Encefálicas/diagnóstico por imagen , Humanos , Neoplasias Meníngeas/diagnóstico por imagenAsunto(s)
Silla Turca , Adenoma de los Conductos Biliares/secundario , Adolescente , Adulto , Neoplasias Encefálicas/diagnóstico por imagen , Ventrículos Cerebrales , Preescolar , Craneofaringioma/diagnóstico por imagen , Quistes/diagnóstico por imagen , Disgerminoma/diagnóstico por imagen , Femenino , Glioma/diagnóstico por imagen , Humanos , Aneurisma Intracraneal/diagnóstico por imagen , Masculino , Neoplasias Meníngeas/diagnóstico por imagen , Meningioma/diagnóstico por imagen , Pinealoma/diagnóstico por imagen , Neoplasias Hipofisarias/diagnóstico por imagen , Teratoma/diagnóstico por imagen , Tomografía Computarizada por Rayos XAsunto(s)
Cráneo/diagnóstico por imagen , Tuberculosis Meníngea/diagnóstico por imagen , Tuberculosis Osteoarticular/diagnóstico por imagen , Angiografía , Encéfalo/irrigación sanguínea , Hueso Frontal/diagnóstico por imagen , Humanos , Hueso Temporal/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Tuberculoma/diagnóstico por imagenAsunto(s)
Fracturas Craneales/diagnóstico por imagen , Lesiones Encefálicas/diagnóstico por imagen , Lesiones Encefálicas/etiología , Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/etiología , Trastornos Cerebrovasculares/etiología , Niño , Diagnóstico Diferencial , Humanos , Lactante , Recién Nacido , Radiografía , Cráneo/diagnóstico por imagen , Fracturas Craneales/complicaciones , Cicatrización de HeridasAsunto(s)
Encéfalo/irrigación sanguínea , Hemorragia Cerebral/diagnóstico por imagen , Infarto/diagnóstico por imagen , Aneurisma Intracraneal/diagnóstico por imagen , Malformaciones Arteriovenosas Intracraneales/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Anciano , Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/diagnóstico por imagen , Hemorragia Cerebral/inducido químicamente , Hemorragia Cerebral/etiología , Femenino , Glioma/complicaciones , Glioma/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Warfarina/efectos adversosAsunto(s)
Neoplasias Hipofisarias/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adenoma/diagnóstico por imagen , Adolescente , Adulto , Angiografía Cerebral/métodos , Craneofaringioma/diagnóstico por imagen , Síndrome de Silla Turca Vacía/diagnóstico por imagen , Femenino , Glioma/diagnóstico por imagen , Humanos , Aneurisma Intracraneal/diagnóstico por imagen , Masculino , Meningioma/diagnóstico por imagen , Persona de Mediana Edad , Neumoencefalografía/métodosRESUMEN
Anterior atlas clefts (AACs) are rare developmental variants that may mimic fractures. Due to the potential severe implications of craniocervical junction trauma, expeditious differentiation between a Jefferson burst fracture and a congenital cleft is essential in trauma patients. Three cases of AAC are presented. Two cases demonstrated incidental AACs; the third case was associated with a Jefferson burst injury. Computed tomography is most helpful in evaluating the integrity of the atlas; however, plain radiography or pluridirectional tomography are best for evaluating displacement of the lateral masses of C1 in relation to C2.