RESUMEN
BACKGROUND: Changes in T2 relaxation time (T2-TR) and apparent diffusion coefficients (ADC) have been suggested to appear in the intervertebral disc before morphological changes. Such sensitive imaging methods could be beneficial in the targeting and follow-up of intradiscal gene therapy. PURPOSE: To investigate the sensitivity of quantitative magnetic resonance (MR) imaging methods (T2-TR and ADC) in early disc degeneration, using an experimental porcine intervertebral disc injury model, and to investigate their sensitivity in depicting biochemically controlled degenerative changes in the disc. MATERIAL AND METHODS: Six juvenile pigs underwent experimental annular stab incisions, one superficial and one reaching the nucleus pulposus. The animals underwent repeated 1.5T MR imaging and were sacrificed 4 or 8 weeks after operation. Presence of degenerative changes was controlled with biochemical analysis. RESULTS: Discs with full-thickness annular incisions lost 30% of their sagittal mid-slice nucleus pulposus area in 2 weeks (P<0.05). T2-TRs of the respective discs were on average 73% of the control discs (P<0.05). Discs with full-thickness annular lesions showed increased ADC values 4 weeks and reduced ADC values 8 weeks after the operation, compared to control discs (P<0.05). Biochemical analysis showed changes consistent with early degeneration. CONCLUSION: Early traumatic or degenerative changes are detectable with both T2-TR and ADC. The ADC in the early phase after experimental trauma seems to initially increase before decreasing.
Asunto(s)
Imagen de Difusión por Resonancia Magnética/métodos , Disco Intervertebral/lesiones , Disco Intervertebral/patología , Enfermedades de la Columna Vertebral/diagnóstico , Enfermedades de la Columna Vertebral/patología , Animales , Modelos Animales de Enfermedad , Femenino , Procesamiento de Imagen Asistido por Computador/métodos , Sensibilidad y Especificidad , Enfermedades de la Columna Vertebral/etiología , Porcinos , Factores de Tiempo , Heridas PunzantesRESUMEN
The series consisted of 200 patients on whom lumbar myelography was performed for sciatica. After myelography, a disc operation was carried out on 95 patients. The episode of sciatica was the first for 90 patients. Objective neurologic signs were present in 185 patients, while 15 had only subjective symptoms. Definite or possible disc herniation was revealed by myelography in 66%. Most positive findings were located at the L4-L5 interspace. The clinical diagnostic accuracy rate was assessed from the patients' histories. As confirmed by operation, the accuracy of the clinical diagnostics was 52%, and the accuracy rate of myelography was 90%. The rate of false positive findings in myelography was 4%, that of false negative findings 6%. When the clinical or myelographic diagnosis was definitive, a disc herniation or protrusion was always found at operation. Almost one fourth of the clinically diagnosed definite herniations were not treated surgically because myelography proved negative. One fifth of those patients in whom myelography revealed an unequivocal disc herniation were not operated on because these patients had clinically improved before being admitted to myelography. The results of this study justify the following conclusions: the clinical level diagnostics of a disc herniation is rather unreliable, and myelography is therefore always indicated before operation; myelography should only be performed in those cases in which there is a clear clinical indication for surgery; myelography ought to be performed within 1 week; an unequivocal positive finding in myelography predicts a good operative result.
Asunto(s)
Desplazamiento del Disco Intervertebral/diagnóstico , Vértebras Lumbares/diagnóstico por imagen , Mielografía , Adolescente , Adulto , Anciano , Errores Diagnósticos , Femenino , Humanos , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Desplazamiento del Disco Intervertebral/cirugía , Masculino , Persona de Mediana EdadRESUMEN
Reports on 217 arthrographies of the knee joint with operative control. Partly or entirely erroneous roentgen diagnoses were made in 4.8-16.3% of the cases, depending upon the technique by which the patients had been examined. Lateral meniscus lesion was wrongly diagnosed three times as often as the medial lesion. The lowest incidence of wrong diagnoses occurred when examining via the medium format technique.