No abstract

Three premier research outfits are scaling back ambitions—and struggling to maintain local staffs as funds grow scarce.

No abstract

No abstract

In vivo measurement of lumbar spine configuration is useful for constructing quantitative biomechanical models. Positional magnetic resonance imaging (MRI) accommodates a larger range of movement in most joints than conventional MRI and does not require a supine position. However, this is achieved at the expense of image resolution and contrast. As a result, quantitative research using positional MRI have required long reconstruction times and are sensitive to incorrectly identifying the vertebral boundary due to low contrast between bone and surrounding tissue in the images. We present a semi-automated method used to obtain digitized reconstructions of lumbar vertebrae in any posture of interest. This method combines a high-resolution reference scan with a low-resolution postural scan to provide a detailed and accurate representation of the vertebrae in the posture of interest. Compared to a criterion standard, translational reconstruction error ranged from 0.7 mm to 1.6 mm and rotational reconstruction error ranged from 0.3 degrees to 2.6 degrees. Intraclass correlation coefficients indicated high interrater reliability for measurements within the imaging plane (ICC = 0.97−0.99). Computational efficiency indicates that this method may be used to compile data sets large enough to account for population variance, and potentially expand the use of positional MRI as a quantitative biomechanics research tool.