T mapping of the meniscus is a biomarker for early osteoarthritis.

Purpose: To evaluate in vivo T mapping as quantitative, imaging-based biomarker for meniscal degeneration in humans, by studying the correlation between T relaxation time and degree of histological degeneration as reference standard.

Methods: In this prospective validation study, 13 menisci from seven patients with radiographic knee osteoarthritis (median age 67 years, three males) were included. Menisci were obtained during total knee replacement surgery.

Compartmentalization of Gd liposomes: the quenching effect explained.

Cationic liposomes carrying high [Gd] can be used as efficient cell-labeling agents. In a compartmentalized state, Gd can cause signal loss (relaxivity quenching). The contributions of liposomal [Gd], size and compartmentalization state to relaxivity quenching were assessed.

Nanoparticles and clinically applicable cell tracking.

In vivo cell tracking has emerged as a much sought after tool for design and monitoring of cell-based treatment strategies. Various techniques are available for pre-clinical animal studies, from which much has been learned and still can be learned. However, there is also a need for clinically translatable techniques.

T1 mapping in the rat myocardium at 7 tesla using a modified CINE inversion recovery sequence.

Purpose: To evaluate the reproducibility and sensitivity of the modified CINE inversion recovery (mCINE-IR) acquisition on rats for measuring the myocardial T1 at 7 Tesla.

Materials And Methods: The recently published mCINE-IR acquisition on humans was applied on rats for the first time, enabling the possibility of translational studies with an identical sequence. Simulations were used to study signal evolution and heart rate dependency.

In vivo quantitative assessment of cell viability of gadolinium or iron-labeled cells using MRI and bioluminescence imaging.

In cell therapy, noninvasive monitoring of in vivo cell fate is challenging. In this study we investigated possible differences in R₁, R₂ or R₂* relaxation rate as a measure of overall cell viability for mesenchymal stem cells labeled with Gd-liposomes (Gd-MSCs) or iron oxide nanoparticles (SPIO-MSCs). Cells were also transduced with a luciferase vector, facilitating a correlation between MRI findings and cell viability using bioluminescence imaging (BLI).

Cationic Gd-DTPA liposomes for highly efficient labeling of mesenchymal stem cells and cell tracking with MRI.

In the current study cell labeling was performed with water-soluble gadolinium (Gd)-DTPA containing liposomes, to allow for cell tracking by MRI. Liposomes were used to assure a highly concentrated intracellular build up of Gd, aiming to overcome the relatively low MRI sensitivity of Gd (compared to T2 contrast agents). Liposomes were positively charged (cationic) to facilitate uptake by binding to anionic charges in the cell membrane of bone marrow-derived mesenchymal stem cells (MSCs).

Cell tracking in cardiac repair: what to image and how to image.

Stem cell therapies hold the great promise and interest for cardiac regeneration among scientists, clinicians and patients. However, advancement and distillation of a standard treatment regimen are not yet finalised. Into this breach step recent developments in the imaging biosciences.