ABSTRACT
Abstract Objective: To promote advanced research using magnetic resonance imaging (MRI) in the diagnosis of and screening for osteoporosis by looking for correlations among the T-scores measured by dual-energy X-ray absorptiometry (DEXA), the apparent diffusion coefficient (ADC) values on diffusion-weighted imaging (DWI), and the T1-weighted signal intensity values. Materials and Methods: This was a prospective study of postmenopausal women with no contraindications to MRI and no history of cancer who underwent DEXA within 30 days before or after the MRI examination. A 3.0-T scanner was used in order to acquire sagittal sequences targeting the lumbar spine. Results: Thirteen women underwent DEXA and MRI. In two cases, the MRI was discontinued early. Therefore, the final sample comprised 11 patients. The ADC values and T1-weighted signal intensity were found to be higher in patients with osteoporosis. However, among the patients > 60 years of age with osteoporosis, ADC values were lower and T1-weighted signal intensity was even higher. Conclusion: It is unlikely that MRI will soon replace DEXA for the diagnostic workup of osteoporosis. Although DWI and ADC mapping are useful for understanding the pathophysiology of osteoporosis, we believe that T1-weighted sequences are more sensitive than is DWI as a means of performing a qualitative analysis of vertebral alterations.
Resumo Objetivo: Promover pesquisas avançadas usando ressonância magnética (RM) no diagnóstico e rastreamento de osteoporose, procurando correlações entre os escores T medidos por absorciometria de raios-X de dupla energia (DEXA), valores de coeficiente de difusão aparente (ADC) na difusão e valores de intensidade de sinal ponderado em T1. Materiais e Métodos: Estudo prospectivo de mulheres na pós-menopausa sem contraindicações para RM e sem histórico de câncer que foram submetidas a DEXA 30 dias antes ou após o exame de RM. Um scanner 3.0-T foi utilizado para adquirir sequências sagitais direcionadas à coluna lombar. Resultados: Treze mulheres foram submetidas a DEXA e RM. Em dois casos, a RM foi interrompida precocemente. Portanto, a amostra final foi composta por 11 pacientes. Os valores de ADC e intensidade de sinal ponderado em T1 foram mais elevados nas pacientes com osteoporose. No entanto, no subgrupo de pacientes > 60 anos de idade com osteoporose, os valores de ADC foram menores e a intensidade do sinal ponderado em T1 foi ainda maior. Conclusão: É improvável que a RM substitua DEXA para a investigação diagnóstica da osteoporose no futuro próximo. Embora a difusão e o mapeamento ADC sejam úteis para a compreensão da fisiopatologia da osteoporose, acreditamos que as sequências ponderadas em T1 são mais sensíveis do que a difusão como meio de realizar uma análise qualitativa das alterações vertebrais.
ABSTRACT
Objective To observe the early changes of related indexes after high dose of 60Co γ-ray irradiation on rhesus monkey hematopoietic system.Methods A total of 33 rhesus monkeys were randomly divided into normal control and different irradiation control group,rhesus monkeys in irradiation control group were given different doses(4,8,12 Gy) irradiation to establish acute radiation sickness(ARS) models.XE-2100 automatic blood cell analyzer detected the peripheral blood before and after the irradiation of 3,6,9,12,24,48,80 h.The rhesus monkeys were sacrificed to have a observation of sternum pathological changes at 6,48 and 80 h after 4,8,12 Gy 60Co γ-ray irradiation.Results The number of white blood cell in peripheral blood of the rhesus monkeys after 4 and 8 Gy 60Co γ-ray irradiation were lower than that before irradiation at 3 h after irradiation,as was significant increased at 6 h after irradiation,the highest values were 136.04%.and 221.38% after 9 h(with before irradiation values was 100.00%,the same below),become obviously drooped from 12 h after irradiation,show clearly temporary peak.But the number of white blood cell after 12 Gy 60Co γ-ray irradiation was significant increased at 6 h after irradiation,at the highest of 9 h,become obviously drooped from 12 h after irradiation.Peripheral blood neutrophile count was significant increased at 6 h after irradiation,at the highest of 9 h,become obviously drooped from 12 h after irradiation.Peripheral blood lymphocyte count fell sharply after irradiation,3 h detection value was only 12.02%-25.04% of before irradiation.Sternal bone marrow nucleated cell number decreased sharply after irradiation,the more irradiation dose,the less residual hematopoietic cells.Conclusion In the early stage of BM-ARS,temporary peaktime node of the white blood cell and neutrophil count could be regarded as the best delivery time of hematopoietic cytokine therapy.