Level III, case-control.

The 3D modeling allows for a more accurate evaluation of coronal alignment compared to 2D, eliminating bias due to wrong knee positioning.

No abstract

Intraarticular concentration of gadolinium tetraazacyclododecanetetraacetic acid (DOTA) after intravenous injection and the diagnostic contribution of the subsequent arthrographic effect were assessed for meniscal lesions in the knee. Kinetics were studied in three healthy volunteers. Passage of contrast material into the synovial fluid of the joint was evaluated in 53 knees by measuring the signal intensity on T1-weighted images before, immediately after, and 1 hour after injection. Synovial fluid enhancement was 1.46-fold greater than the unenhanced value after 10 minutes, plateaued after 30 minutes, and was 1.95-fold greater after 1 hour. In articular fluid samples from four patients 1 hour after intravenous injection, the average intraarticular concentration was 141 mumol +/- 47 (1 standard deviation) at atomic absorption spectrophotometry. Knee mobilization improved the passage of contrast material into the synovial fluid by approximately 120% at 10 minutes and 25% at 1 hour. In eight of 39 tears, unenhanced standard sequences were equivocal. In seven of these uncertain cases, delayed contrast-enhanced images permitted adequate interpretation. Intraarticular concentration of Gd-DOTA produces a sufficient arthrographic effect for meniscus evaluation.

Tumours of the nail apparatus are often the subject of diagnostic dilemma. Until now, no reliable imaging methods have been available to assess these lesions correctly. We report the results of high and very high-resolution magnetic resonance imaging (MRI), which have been correlated with the anatomical findings in 14 cases of nail apparatus pathology, and discuss the possible contribution of MRI to diagnosis. With very high-resolution MRI, accurate analysis of the anatomy of the nail apparatus is possible, and lesions as small as 1 mm can be detected. An expansive process can be excluded when results are negative. Glomus tumour, mucoid pseudocyst, fibrokeratoma, and exostosis can be differentiated because of their different MRI characteristics. This is of importance when the exact nature of a subungual tumour cannot be determined by clinical findings alone. Measurement, determination of the exact localization of the tumour, and the study of its relationship to the other structures, can provide guidance for subsequent surgical procedures. MRI is reliable and accurate in the delineation of lesions, and provides a new tool for the investigation of pathology of the nail apparatus.