RESUMO
No brain abnormalities are usually detected on conventional magnetic resonance imaging (MRI) in benign hereditary chorea (BHC); there are currently no studies with advanced techniques in literature. We investigated whether conventional and advanced MRI techniques could depict regional brain abnormalities in two familial BHC patients and 24 healthy controls. No brain abnormalities on conventional scans were detectable; also, no significant differences in fractional anisotropy of the basal nuclei were observed. Volumetric analysis showed a decreased volume of the striatum bilaterally compared with controls, whereas spectroscopy demonstrated a significant increased myoinositol/creatine ratio bilaterally, a reduction of choline/creatine ratio bilaterally, and of N-acetyl-aspartate/creatine in the right putamen. With the limits of the small sample size in the patient group, these data show that, despite the absence of macroscopic changes on conventional MRI, volumetric and metabolic abnormalities are present in the basal nuclei of BHC patients.
Assuntos
Coreia/patologia , Corpo Estriado/patologia , Putamen/patologia , Adolescente , Adulto , Anisotropia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Tamanho do ÓrgãoRESUMO
Extramedullary haematopoiesis is the production of blood elements outside the bone marrow cavity. In our case computed tomography and magnetic resonance imaging revealed the presence of a rare localization of extramedullary haematopoiesis with encasement of the biliary system in a 59 years-old male Caucasian patient, with chronic myelofibrosis and hepatic failure's symptomatology. Computed tomography detected the presence of homogeneous hypodense tissue around intra-hepatic bile ducts with minimal contrast enhancement, strongly suggestive for extramedullary haematopoiesis. Magnetic resonance confirmed the presence of a solid tissue surrounding the biliary tree, showing late enhancement after gadolinium administration suggestive for non-active lesion of extramedullary haematopoiesis. Final diagnosis was established by percutaneous biopsy.
RESUMO
The field of application of magnetic resonance spectroscopy (MRS) in biomedical research is expanding all the time and providing opportunities to investigate tissue metabolism and function. The data derived can be integrated with the information on tissue structure gained from conventional and non-conventional magnetic resonance imaging (MRI) techniques. Clinical MRS is also strongly expected to play an important role as a diagnostic tool. Essential for the future success of MRS as a clinical and research tool in biomedical sciences, both in vivo and in vitro, is the development of an accurate, biochemically relevant and physically consistent and reliable data analysis standard. Stable and well established analysis algorithms, in both the time and the frequency domain, are already available, as is free commercial software for implementing them. In this study, we propose an automatic algorithm that takes into account anatomical localisation, relative concentrations of white matter, grey matter, cerebrospinal fluid and signal abnormalities and inter-scan patient movement. The endpoint is the collection of a series of covariates that could be implemented in a multivariate analysis of covariance (MANCOVA) of the MRS data, as a tool for dealing with differences that may be ascribed to the anatomical variability of the subjects, to inaccuracies in the localisation of the voxel or slab, or to movement, rather than to the pathology under investigation. The aim was to develop an analysis procedure that can be consistently and reliably applied in the follow up of brain tumour. In this study, we demonstrate that the inclusion of such variables in the data analysis of quantitative MRS is fundamentally important (especially in view of the reduced accuracy typical of MRS measures compared to other MRI techniques), reducing the occurrence of false positives.
