RESUMO
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.
Assuntos
Atlas Cervical/anormalidades , Atlas Cervical/lesões , Fraturas da Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Acidentes de Trânsito , Adolescente , Adulto , Atlas Cervical/diagnóstico por imagem , Diagnóstico Diferencial , Feminino , Seguimentos , Futebol Americano/lesões , Humanos , Masculino , Ferimentos não Penetrantes/diagnóstico por imagemRESUMO
In recent years MR has been the major advancement in the imaging of lumbar disc disease. Its advantages include multiplanar imaging, excellent resolution, and absence of ionizing radiation. Although CT remains an efficient and accurate method of evaluating the spine, we currently recommend MR imaging as the best initial examination. Myelography with follow-up CT scans should be reserved for specific patients in whom additional information is needed after MR images or CT scans.
Assuntos
Deslocamento do Disco Intervertebral/diagnóstico , Vértebras Lombares , Estenose Espinal/diagnóstico , Humanos , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia , Imageamento por Ressonância Magnética , Mielografia , Estenose Espinal/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
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.
