Finding the best clearing approach - Towards 3D wide-scale multimodal imaging of aged human brain tissue.

The accessibility of new wide-scale multimodal imaging techniques led to numerous clearing techniques emerging over the last decade. However, clearing mesoscopic-sized blocks of aged human brain tissue remains an extremely challenging task. Homogenizing refractive indices and reducing light absorption and scattering are the foundation of tissue clearing.

Measuring the iron content of dopaminergic neurons in substantia nigra with MRI relaxometry.

In Parkinson's disease, the depletion of iron-rich dopaminergic neurons in nigrosome 1 of the substantia nigra precedes motor symptoms by two decades. Methods capable of monitoring this neuronal depletion, at an early disease stage, are needed for early diagnosis and treatment monitoring. Magnetic resonance imaging (MRI) is particularly suitable for this task due to its sensitivity to tissue microstructure and in particular, to iron.

Biophysically motivated efficient estimation of the spatially isotropic component from a single gradient-recalled echo measurement.

Purpose: To propose and validate an efficient method, based on a biophysically motivated signal model, for removing the orientation-dependent part of using a single gradient-recalled echo (GRE) measurement.

Methods: The proposed method utilized a temporal second-order approximation of the hollow-cylinder-fiber model, in which the parameter describing the linear signal decay corresponded to the orientation-independent part of . The estimated parameters were compared to the classical, mono-exponential decay model for in a sample of an ex vivo human optic chiasm (OC).