Whiplash-related injuries and manifestations, typically neck pain, following car collisions are known to potentially disable individuals with a high and increasing cost to society. There is limited knowledge regarding the temporomandibular joint (TMJ) sequelae following whiplash trauma. Previous studies are typically based on retrospective data and few follow-ups are prospective and controlled in design. Furthermore, previous follow-ups have not included magnetic resonance (MR) imaging, which is a prerequisite for verification of TMJ status. The aims of this prospective long-term study were (i) to determine frequency of inaccurate recall of TMJ symptoms in patients with a history of whiplash trauma, and (ii) to evaluate incidence, prevalence and progression of TMJ pathology, verified with MR imaging, and TMJ symptoms in patients after whiplash trauma, compared with the natural course in matched volunteers. We studied 60 consecutive patients who had neck symptoms following a rear-end car collision and were seen at a hospital emergency department. Bilateral TMJ MR imaging and clinical examination were performed at inception and at follow-up on average 15 years later. A self-administered questionnaire regarding TMJ symptoms (pain, dysfunction, or both) and a subsequent interview were performed at inception, at the one-year, and 15-year follow-up. Fifty-seven patients (95%) participated in all three examinations (85% for MR imaging examinations). Concurrently, 53 volunteers matched by age and sex followed the same protocol. Fifty volunteers (94%) participated in all three examinations (89% for MR imaging examinations). Ethics approval of the study protocol and informed consent from all participants was obtained. The calculated agreement between each patient’s inceptive and retrospective reports on TMJ symptoms yielded a kappa value of 0.41 (95% CI 0.18-0.64). Sixteen patients (40%) had inaccurate recall one year after whiplash trauma. There was no statistically significant difference in TMJ symptoms reported by the patients to be present before whiplash trauma compared with matched volunteers at inception. Prevalence of TMJ symptoms increased significantly with whiplash trauma and the increase remained stable throughout the 15-year study period, which contrasted to the natural course in volunteers. After one year the difference in prevalence between patients and volunteers was 54% versus 21% (p=0.0003) and after 15 years 49% versus 18% (p=0.0017). There was no statistically significant difference between patients and volunteers in prevalence of TMJ disc displacement either at inception (63% versus 53%) or at 15-year follow-up (63% versus 55%). TMJ disc displacement was significantly more prevalent in symptomatic volunteers compared with asymptomatic volunteers (89% versus 31%, p=0.0002). Incidence or progression of MR imaging verified TMJ pathology did not differ between patients and volunteers. This prospective 15-year follow-up concludes - that future studies on TMJ sequelae following whiplash trauma should be prospective in study design with examinations conducted in close proximity to whiplash trauma. This allows for reliable baseline status and potential bias of inaccurate recall of symptoms is minimized. - that future controlled studies on TMJ pathology in patients should include control groups of not only asymptomatic but also symptomatic volunteers in order to avoid potentially biased conclusions. - that one of three patients exposed to whiplash trauma can be expected to develop TMJ symptoms beyond that which corresponds to the natural course in volunteers. This finding and previously reported impairment of jaw function in patients with symptoms after whiplash trauma points to the need for including TMJs and related muscles in routine medical examinations of patients with symptoms following whiplash trauma. - that adult individuals presenting with no or mild TMJ symptoms seldom show development or aggravation of TMJ pathology and there is no or little indication for TMJ treatment of these adult individuals. This is in contrast to the higher progression of TMJ pathology previously reported for adult patients with TMJ symptoms, which requires treatment.

A novel framework for quantitative analysis of shape and function in magnetic resonance imaging (MRI) of the brain is proposed. First, an efficient method to compute invariant spherical harmonics (SPHARM) based feature representation for real valued 3D functions was developed. This method addressed previous limitations of obtaining unique feature representations using a radial transform. The scale, rotation and translation invariance of these features enables direct comparisons across subjects. This eliminates need for spatial normalization or manually placed landmarks required in most conventional methods [1-6], thereby simplifying the analysis procedure while avoiding potential errors due to misregistration. The proposed approach was tested on synthetic data to evaluate its improved sensitivity. Application on real clinical data showed that this method was able to detect clinically relevant shape changes in the thalami and brain ventricles of Parkinson's disease patients. This framework was then extended to generate functional features that characterize 3D spatial activation patterns within ROIs in functional magnetic resonance imaging (fMRI). To tackle the issue of intersubject structural variability while performing group studies in functional data, current state-of-the-art methods use spatial normalization techniques to warp the brain to a common atlas, a practice criticized for its accuracy and reliability, especially when pathological or aged brains are involved [7-11]. To circumvent these issues, a novel principal component subspace was developed to reduce the influence of anatomical variations on the functional features. Synthetic data tests demonstrate the improved sensitivity of this approach over the conventional normalization approach in the presence of intersubject variability. Furthermore, application to real fMRI data collected from Parkinson's disease patients revealed significant differences in patterns of activation in regions undetected by conventional means. This heightened sensitivity of the proposed features would be very beneficial in performing group analysis in functional data, since potential false negatives can significantly alter the medical inference. The proposed framework for reducing effects of intersubject anatomical variations is not limited to functional analysis and can be extended to any quantitative observation in ROIs such as diffusion anisotropy in diffusion tensor imaging (DTI), thus providing researchers with a robust alternative to the controversial normalization approach.

Multi-echo T2 relaxation measurements of the human spinal cord (SC) reveal a short T2 pool of water believed to arise from water trapped between myelin bilayers, where the proportion of this water to the total water signal is called the myelin water fraction (MWF). In the present study, MWF were measured in the healthy human cervical spine at the C4-C6 vertebral levels in vivo using a 3D modified 32 echo CPMG sequence to acquire axial slices perpendicular to the cord. Volunteers were recruited in two age ranges, under 30 years old and over 50 years old, and a subset of both groups were scanned twice to test reproducibility. Mean MWF in the dorsal and lateral column WM of the group under 30 years of age was 0.29 (0.01) (mean(SE)), which agrees with previously reported MWF values in the cervical spine. The mean absolute difference between two scans was 0.06 or 26%. A negative correlation between WM MWF and age was hinted at in these findings, however more subjects are required to improve statistical power. This study paves the way for the use of 3D myelin water imaging in the cervical spine at 3.0T for the assessment of SC WM pathology.

Thesis (Ph.D.)--Tufts University, 2002. / Adviser: David Weaver. Submitted to the Dept. of Physics. Includes bibliographical references (leaves 218-243). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: Biomedical Engineering; Collage remodelling; MRI. Includes bibliographical references (leaves 83-87).

Diss. Linköping : Univ., 2003.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). "October 2007." Includes bibliographical references (leaves 159-171). Also available via the World Wide Web.

Thesis (Ph.D.)--University of Western Sydney, Nepean, 2000. / "Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy University of Western Sydney, Nepean March 2000." Bibliography : leaves 164-181.