Segmentation of the quadratus lumborum muscle using statistical shape modeling.

Purpose: To compare automated segmentation of the quadratus lumborum (QL) based on statistical shape modeling (SSM) with conventional manual processing of magnetic resonance (MR) images for segmentation of this paraspinal muscle.

Materials And Methods: The automated SSM scheme for QL segmentation was developed using an MR database of 7 mm axial images of the lumbar region from 20 subjects (cricket fast bowlers and athletic controls). Specifically, a hierarchical 3D-SSM scheme for segmentation of the QL, and surrounding psoas major (PS) and erector spinae+multifidus (ES+MT) musculature, was implemented after image preprocessing (bias field correction, partial volume interpolation) followed by image registration procedures to develop average and probabilistic MR atlases for initializing and constraining the SSM segmentation of the QL.

Quadratus lumborum asymmetry and L4 pars injury in fast bowlers: a prospective MR study.

Purpose: This prospective study examined the association between quadratus lumborum (QL) asymmetry and the development of symptomatic pars interarticularis lesions in the lumbar spine of adolescent cricket fast bowlers.

Methods: Annual magnetic resonance imaging was used to measure QL volume asymmetry and for identifying pars lesions of the lumbar vertebrae in fast bowlers (N=51) and a control group of swimmers (N=18). Manual segmentation of axial images spanning the lumbar spine was performed to calculate percent QL asymmetry relative to the bowling- or throwing- (swimmers) arm side.

Pars interarticularis stress lesions in the lumbar spine of cricket fast bowlers.

Purpose: This prospective magnetic resonance (MR) imaging study investigated the development of symptomatic pars lesions in the lumbar spine of adolescent cricket fast bowlers.

Methods: Annual MR examinations of the lumbar spine in male fast bowlers (N = 51) and swimmers (N = 20) without a prestudy history of symptomatic back injury were conducted to identify stress-induced pars injuries over 4 and 2 yr periods, respectively.

Results: Symptomatic L4 and L5 pars lesions developed in 11 of 51 and 1 of 51 of the bowlers, respectively.

MR morphometry of posterior tibialis muscle in adult acquired flat foot.

We conducted magnetic resonance imaging of the posterior tibial (PT) and flexor digitorum longus (FDL) muscle bellies in 12 patients undergoing surgical treatment for unilateral posterior tibial tendon (PTT) dysfunction. All patients had atrophy of the PT muscle compared to the normal leg (mean 10.7%, p = 0.