RESUMEN
Recently, a fiber visualization method for high-angular resolution diffusion-weighted magnetic resonance imaging (MRI) data was proposed using a multiple-kernel line integral convolution (LIC) algorithm and an anisotropic spot pattern. This processing routine leads to high contrast color-coded LIC maps that are capable of visualizing local anisotropy information and regional fiber architecture. In this paper, we evaluate and validate this method by applying it to simulated datasets and to in vivo diffusion MRI data of children and adults with different disease conditions and healthy volunteers. Compared to routine clinical fiber visualization (color-coded fractional anisotropy, FA maps, and fiber tractography), it has the advantage of visualizing complex local fiber architecture in a fully automated way. The results indicate that this method is capable of reliably delineating normal fiber architecture and fibers infiltrated, displaced, or disrupted by lesions and is therefore a promising tool in the clinical context.
Asunto(s)
Algoritmos , Encéfalo/diagnóstico por imagen , Imagen de Difusión Tensora , Adolescente , Adulto , Anisotropía , Niño , Imagen de Difusión por Resonancia Magnética , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Fibras Nerviosas MielínicasAsunto(s)
Encéfalo/patología , Enfermedades por Almacenamiento Lisosomal/diagnóstico , Imagen por Resonancia Magnética , Adolescente , Niño , Preescolar , Femenino , Gangliosidosis/diagnóstico , Humanos , Lactante , Leucodistrofia de Células Globoides/diagnóstico , Leucodistrofia Metacromática/diagnóstico , Masculino , Mucopolisacaridosis/diagnóstico , Lipofuscinosis Ceroideas Neuronales/diagnóstico , Enfermedades de Niemann-Pick/diagnóstico , Adulto JovenRESUMEN
Metachromatic leukodystrophy (MLD) is a rare inborn error of metabolism leading to severe neurological symptoms and early death. Hematopoietic SCT (HSCT) is considered a treatment option, but results are inconsistent and comparison with natural history is practically missing. We compare a girl with juvenile MLD 10 years after allogeneic HSCT not only with her untreated sister, but also with a large cohort of untreated patients. The girl received HSCT at the age of 5 years when first motor signs appeared. Over 10 years she was stable with respect to her clinical course and gained cognitive abilities. Magnetic resonance imaging (MRI) showed clear regression of white matter changes and magnetic resonance spectroscopy (MRS) demonstrated a reversal of the initial choline increase and N-acetyl-aspartate (NAA) decrease. Only axonal demyelinating neuropathy showed some progression. Her gross motor function and MRI-scores were clearly better compared with her sister and the cohort of untreated patients. Difference to her sister became apparent only 4 years after HSCT. We conclude that HSCT, early in the course of disease, can lead to stabilization of juvenile MLD with a course clearly different from the natural history. HSCT may prevent disease progression, if performed sufficient time before loss of walking, which typically initiates rapid deterioration.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Leucodistrofia Metacromática/patología , Leucodistrofia Metacromática/cirugía , Adolescente , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Humanos , Leucodistrofia Metacromática/diagnóstico , Masculino , Resultado del TratamientoRESUMEN
In order to quantify human brain development in vivo, high resolution magnetic resonance images of 158 normal subjects from infancy to young adulthood were studied (age range 3 months-30 years, 71 males, 87 females). Data were analysed using algorithms based on voxel-based morphometry (VBM) (an objective whole brain processing technique) to generate global volume measures of whole brain, grey matter (GM) and white matter (GM). Gender-specific development of WM and GM volumes is characterised using a piecewise polynomial growth curve model to account for the non-linear nature of human brain development, implemented using Markov chain Monte Carlo simulation. The statistical method employed in this study proved to be successful and robust in the characterisation of brain development. The resulting growth curve parameter estimates lead to the following observations: total brain volume is demonstrated to undergo an initial rapid spurt. The total GM volume peaks during childhood and decreases thereafter, whereas total WM volume increases up to young adulthood. Relative to brain size, GM decreases and WM increases markedly over this age range in a non-linear manner, resulting in an increasing WM-to-GM ratio over much of the observed age range. In addition, significant gender differences are found. In general, brain volume and total white and grey matter volume are larger in males than in females, with a time-dependent difference over the age range studied. Over part of the observed age range females tend to have more GM volume relative to brain size and lower WM-to-GM ratio than males. The presented findings should be taken into account when investigating physiological and pathological changes during brain development.