MR microimaging of articular cartilage and contrast enhancement by manganese ions

Abstract

Saline solutions of manganese ions (Mn2+) were used as articular contrast agents in magnetic resonance microscopy (9.4 T) of cartilage of chicken femoral condyles and pig temporomandibular joints. The diffusion of Mn2+ from the articular surface into the cartilage matrix led to a strong contrast enhancement in the cartilage. The combination of the high spatial resolution and the contrast enhancement allowed the visualization of fine structures (tissue types) in the cartilage, which correlate with the tissue zones in histological sections stained with cationic dyes. We assume that the electrostatic interactions between the negatively charged groups of the proteoglycans and Mn2+ are most important for the mechanism of contrast enhancement. Hence, the different signal intensities of the various zones of cartilage indicate differences in density of proteoglycans. The intraarticular injection of the cationic contrast agent could improve the possibility of an early diagnosis of cartilage dysfunction and degeneration.

Short TE MR Microscopy: Accurate measurement and zonal differentiation of normal hyaline cartilage

“…6 is probably due to increase hydration o f the cartilagt: surface rather than any anatomical feature. Variation i n rngional T , was not more than 20.05 s over tho entire cartilage region, hence inversion recovery mothods are not likely t o lead to good regional contrast with in cartilage.…”

The morphology of articular cartilage assessed by magnetic resonance imaging (MRI)

“…Intraarticular contrast agents, which greatly enhance the delineation of the articular surface [6,10,21,22], are invasive and cause patient discomfort. Therefore other techniques have been developed to improve contrast, such as MTC (magnetic transfer contrast) [39,[42][43][44], MPRAGE (magnetization-prepared rapid gradient echo) [29], DESS (dual echo at steady state) [24] and fat suppression [30,37].…”

Observation of sGAG content of human hip joint cartilage in different old age groups based on EPIC micro-CT

“…However, these traditional methods are destructive and time consuming. Nondestructive techniques, including ultrasound (US) and magnetic resonance imaging (MRI), have also been used to study sGAG content in AC (15–19). US, a less expensive imaging technique, has been given much attention in the research of sGAG loss during AC degeneration.…”

“…MRI, together with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), can provide information about 3D images of the cartilage, sGAG content in vitro and in clinical applications. However, its high cost, relative long imaging time and low resolution limit its application in small specimens in the lab (18,19). …”