Imaging the dome of the liver can be a very challenging area to image by Ultrasound. Due to its position inside the ribcage there can be difficulty with rib shadowing artifacts causing the sonographer to miss small lesions. The X6–1 Matrix transducer is one of the newest of its kind and claims to be the better multi-use transducer. Its larger aperture reduces rib artifacts and is composed of PureWave Crystal Technology. A phantom will serve as a great approach in this abdominal study to visually compare the lesions between MRI (gold standard) and the new X6–1 Matrix Ultrasound transducer. The X6–1 transducers did reveal minimal rib shadowing and the small lesions were identified.

AIMS: Multiple studies have shown that arthrocentesis is an effective treatment for internal derangement of the temporomandibular joint. However, it is not known which patient groups will respond to this procedure. It is often difficult for surgeons to preoperatively the outcome of athrocentesis. This had led some researchers to analyze and evaluate specific variables which could possibly be used as prognostic factors to predict the outcome of arthrocentesis. None of those studies used the amount of disc displacement as a prognostic factor to assess the treatment outcome of arthrocentesis. Therefore, our study objective was to evaluate the amount of disc displacement as a prognostic factor for the outcome of arthrocentesis in patients with Internal derangement of the tempromandibular joint. MATERIALS AND METHODS: The study involved a retrospective review of the treatment records of 46 patients who underwent arthrocentesis of the TMJ by a single surgeon between 2010 and 2013. A prognostic factor evaluated for its effect on the treatment outcome of TMJ arthrocentesis in this study was the degree of disc displacement. For study purposes, patients were divided into two groups: 1) Success group, and, 2) Failure group. Patients were categorized as successful if they met the success criteria prescribed by the American Association of Oral and Maxillofacial Surgeons in 1995. MRI of TMJ was performed in two steps. Initially, oblique parasagittal sections were scanned with a 1.5 T MRI machine. The amount of disc displacement was analyzed from sagittal oblique views of the MRI scans in closed mouth positions by measuring the angle between the posterior band of the articular disc and the center of the condylar head. The disc is considered to be in its normal position when the thicker portion of its posterior band lies within ±10° on the 12 o'clock position. First, the condylar head was identified, and a circle was established to describe the outline of the anterior, posterior, and superior surfaces of the condylar head; this allowed separation of the condylar head from the neck region. Second, the center of the circle was identified and a vertical line was drawn from the center of the circle. The last step was to measure the degree of displacement from this vertical line to the posterior band of the disc. Findings were compared for patients in the two groups for the following variables: age (continuous), disc displacement (continuous), and gender (female or male). P-value were calculated for differences in continuous or categorical variables using a T-test or Pearson's chi-squared test, respectively. The mean MMO, pain and diet scores were also reported in the preoperative group and 12 months postoperative group by outcome status. Statistical significance was set at p < .05 based on a two-tailed test. SPSS was used for all statistical analyses (SPSS Inc, Chicago, IL, 1997). RESULTS: 46 patients with 46 joints were evaluated in the present study. Average age of patients was 31 years with arrange of 24 to 46 years. 35 cases (76.1%) were classified as successful and 11 cases (23.9%) were classified as unsuccessful based on the criteria described earlier. In the successful group, the mean MMO score was found to be greater at the 12 months postoperative interval when compared to the preoperative examination. In the unsuccessful group, the mean MMO score was also greater than preoperatively at the 12 months postoperative group but to a lesser extent than seen in the successful group. Pain level improved more in the successful group compared to the unsuccessful group. Diet scores showed improvement in chewing ability in the successful group but remain unchanged in the unsuccessful group There was a statistically significant difference between the two groups in the degree of anteriorly disc displacement. CONCLUSION: In summary, it has been shown that the degree of disc displacement, preoperative pain level, diet score, and MMO can be used as prognostic factors for the outcome of TMJ arthrocentesis. Future investigations should more carefully evaluate the validity of other variables. Identifying prognostic factors for the outcome on arthrocentesis will help with guiding surgeons in the planned evaluation of TMJ cases. More specifically, clinicians will be able to create tailored treatment modalities based upon prognostic factors.

Currently, the world population is aging. People over 75 is one of the fastest growing age groups. This is the group most affected by Alzheimer's disease. Reliable early diagnosis and tracking methods are essential to assist therapy and prevention. This research aims to study anisotropy texture in tomographic brain scans to diagnose and quantify the severity of Alzheimer's disease. A full methodology to study computer tomography, magnetic resonance imaging and multispectral magnetic resonance imaging is presented in this thesis. Before applying any texture method to the tomographic brain images, a segmentation technique has to be used to extract the different regions of interest. We propose the use of connected filters and iterative region merging to perform the segmentation. Gradient vector histogram is applied to study the texture anisotropy of computer tomography scans. Computer tomography scans present evidence of texture changes in demented subjects compare to normal subjects. The overlap between these groups is considerable, so anisotropy texture using computer tomography does not seem to add more useful information to the diagnosis of Alzheimer's disease than other clinical criteria. Another method to study texture anisotropy is grey-level dependance histogram, which is based in a 3D generalisation for arbitrary orientation of the 2D co-occurrence matrices. This texture technique is applied to magnetic resonance imaging scans, where features extracted from the grey matter component have a strong correlation with the mini mental state examination1 scores. Finally, Multispectral Grey-Level Dependence Histogram (MGLDH), Absolute Difference Histogram (ADH) and spatial correlations are texture techniques designed to study multispectral images. These techniques are applied to multispectral magnetic resonance images. We evaluate the performance of the different multispectral texture methods, and compare them with single channel texture methods.

<b>Background:</b> Sport is an important form of physical activity and has been shown to have many health benefits. Cricket is a popular sport in the UK and internationally, but little is known about the short- and long-term health effects of a career in elite cricket. This thesis will describe the long-term physical and mental health of former elite cricketers compared to the general population, explore the association of cricket-related factors with their long-term musculoskeletal health, and evaluate the effect of elite fast bowling on the knee cartilage of current elite fast bowlers. <b>Methods:</b> A sample of male former elite English cricketers was recruited for a cross-sectional retrospective questionnaire study of the long-term health of former cricketers. Chronic conditions in the former cricketers were compared to a general population sample and cricket-related factors including playing position and injury were tested for their association with musculoskeletal outcomes. A sample of male and female current elite fast bowlers was recruited for a biomechanics and cross-sectional MRI study of their knee cartilage. The knee cartilage was compared between the bowlers' trailing leg versus the higher loaded leading leg, and was tested for associations with bowling kinematic and kinetic parameters. <b>Results:</b> The former elite cricketers reported a higher prevalence of osteoarthritis, total hip replacement, total knee replacement, anxiety and depression than the general population sample and a lower prevalence of heart problems than the general population. Injury was the only cricket-related factor analysed to be associated with the musculoskeletal outcomes of joint pain, osteoarthritis, and joint replacement in the former cricketers. The current elite fast bowlers did not demonstrate a statistically significant difference between the compartmental knee cartilage volume in the trailing leg versus the higher loaded leading leg. A clinically significantly greater cartilage volume was found in the lateral tibia compartment of the leading leg than the trailing leg. The lateral tibia cartilage of the leading leg was also found to be significantly associated with the knee flexion/extension moment and abduction/adduction moment at leading leg strike of the bowling action. <b>Conclusions:</b> This research identifies risks and benefits of a career in elite cricket, providing targets for prevention and resource provision for chronic conditions in current cricketers and cricketers transitioning out of elite cricket. These results also suggest that cartilage may be sensitive to bowling loads in current elite fast bowlers, providing evidence that increased physical activity and loading is associated with increased cartilage volume.

abstract: Sensitivity is a fundamental challenge for in vivo molecular magnetic resonance imaging (MRI). Here, I improve the sensitivity of metal nanoparticle contrast agents by strategically incorporating pure and doped metal oxides in the nanoparticle core, forming a soluble, monodisperse, contrast agent with adjustable T2 or T1 relaxivity (r2 or r1). I first developed a simplified technique to incorporate iron oxides in apoferritin to form "magnetoferritin" for nM-level detection with T2- and T2* weighting. I then explored whether the crystal could be chemically modified to form a particle with high r1. I first adsorbed Mn2+ ions to metal binding sites in the apoferritin pores. The strategic placement of metal ions near sites of water exchange and within the crystal oxide enhance r1, suggesting a mechanism for increasing relaxivity in porous nanoparticle agents. However, the Mn2+ addition was only possible when the particle was simultaneously filled with an iron oxide, resulting in a particle with a high r1 but also a high r2 and making them undetectable with conventional T1-weighting techniques. To solve this problem and decrease the particle r2 for more sensitive detection, I chemically doped the nanoparticles with tungsten to form a disordered W-Fe oxide composite in the apoferritin core. This configuration formed a particle with a r1 of 4,870mM-1s-1 and r2 of 9,076mM-1s-1. These relaxivities allowed the detection of concentrations ranging from 20nM - 400nM in vivo, both passively injected and targeted to the kidney glomerulus. I further developed an MRI acquisition technique to distinguish particles based on r2/r1, and show that three nanoparticles of similar size can be distinguished in vitro and in vivo with MRI. This work forms the basis for a new, highly flexible inorganic approach to design nanoparticle contrast agents for molecular MRI. / Dissertation/Thesis / Ph.D. Bioengineering 2012

Adverse drug reactions are common causes of medical injuries. Drug-induced hepatotoxicity remains one of the leading causes of emergency room visits, FDA non-approval, and drug withdrawal from the market. We have investigated the ability of endogenous nucleophilic amino acid residues (K, H, and C) to selectively bind to reactive electrophilic drug metabolites, focusing on acetyl-para-aminophenol (APAP, i.e. Tylenol®), for which hepatotoxicity has recently re- emerged as a major health concern for Canadians. Three peptide sequences were synthesized bearing terminal nucleophilic residues, brominated phenylalanine residues, and c-terminal amides. These peptides were coupled to carboxy methyl dextran coated iron oxide nanoparticles (CMX- IONPs) with a hepatocyte targeting group. IONPs are known for their ability to act as T2-weighted MRI contrast agents, giving us the ability to track them in vivo. This study begins to establish a nanotechnology-based method for the in vivo trapping of NAPQI, the reactive metabolite of APAP, using a cysteine bearing IONP.

Abstract Imaging of the head and spine with CT and/or MRI was performed on 125 Northern Finnish NF1 patients to evaluate the CNS lesions in patients of different ages and their role in diagnosis and follow-up. Manifestations of NF1 in the head were more common in children than in adults. 77% of the children and 33% of the adults had T2 hyperintense brain lesions. Optic gliomas were present in 29% of the patients, in 44% of the children and 10 % of the adults. 8% of the patients had other intracranial tumours . Spinal lesions were seen in 75% of the patients. Hyperintense T2 lesions were most common in the age group of 5 to 9 years. During follow-up of the children, the lesions diminished in 25%, remained unchanged in 36%, showed mixed behaviour in 20% and disappeared in 10%. In 15% they increased in size and number. In one patient a malignant tumour developed at the site of a T2 lesion. Optic gliomas were located intraorbitally and/or prechiasmally in 94%, chiasmally and/or at the hypothalamus in 58% and in other optic areas in 14% of the patients. 52 % of the intraorbital gliomas were bilateral. The gliomas remained unchanged in 68% of the children and 50% of the adults. Other lesions included plexiform neurofibromas, sphenoid bone dysplasias and hydrops of the optic sheath. Optic glioma was more common in children with T 2 hyperintense brain lesions than without them. The other brain tumours included six astrocytomas, including an affected mother and her son. In one patient the astrocytoma regressed spontaneously. Hydrocephalus was seen in 5% of the patients. T2 hyperintense brain lesions were more common and numerous in macrocephaly; all macrocephalic children, but only 59% of the normocephalic children were affected. All children without T2 lesions were normocephalic. The brain measurements did not reveal any specific area to be responsible for macrocephaly. Spinal postural changes and dural ectasias were more common in adults. The spinal cord was affected in two patients. Spinal neurofibromas were seen in 19% of the children and 55% of the adults. Even young children may have severe manifestations. In one family a rare familial type of spinal neurofibromatosis (FSNF) was observed in four adults with bilateral spinal neurofibromas at all levels of the spine. Although both CT and MRI were valuable in CNS imaging, MRI proved to be the method of choice in detecting T2 hyperintense brain lesions, in evaluating the intracranial extent of optic gliomas and hydrops of the optic sheath and lesions of the spinal cord and nerves. MR imaging proved necessary for evaluating the extent of NF1 manifestations and helpful in the diagnosis, screening and follow-up of NF1 patients.

RRx-001 is an anticancer agent that subjects cancer cells to reactive oxygen/nitrogen species (ROS/RNS) and acts as an epigenetic modifier. We have used a thiol-bearing MRI contrast agent, Gd-LC7-SH, to investigate the pharmacodynamics of RRx-001 in CHP-100 Ewing's Sarcoma, HT-29 colorectal carcinoma, and PANC-1 pancreatic carcinoma xenografts in SCID mice. Binding of Gd-LC7-SH to the Cys34 residue on plasma albumin prolongs retention in the tumor microenvironment and increases tumor enhancement on MRI. Mice were imaged by MRI and in vivo T1 maps acquired 50 min (T1(50 min)) after injection of 0.05 mmol/kg Gd-LC7-SH (i.v.) at baseline and 1, 24, and 72 h post-treatment with 10 mg/kg RRx-001 (i.v.). Consistent with an indirect thiol-modifying activity of RRx-001, tumor T150 min at 1 h post-drug was significantly longer than pre-drug tumor T150 min in all three tumor models, with the T150 min remaining significantly longer than baseline through 72 h post-drug in the HT-29 and PANC-1 tumors. The T150 min of CHP-100 tumors recovered to baseline by 24 h post-drug, suggesting a robust anti-oxidant response to the RRx-001 challenge that was presaged by a marked increase in perfusion at 1 h post-drug measured by DCE-MRI. MRI enhanced with Gd-LC7-SH provides a mechanistically rational biomarker of RRx-001 pharmacodynamics.

No description available.

Abstract The fact that the lateral pterygoid muscle (LPM) and related symptoms play an important role in temporomandibular disorders (TMD) is widely recognized. In the study reported here, the LPM was investigated by magnetic resonance imaging (MRI) of patients with TMD. The visibility of the LPM in MRI with different projections was analyzed and a new imaging projection, condyle-the lateral pterygoid muscle projection (CLPM), for the LPM in MRI was introduced. Normal and abnormal findings of the LPM was compared with clinical symptoms of TMD. Compared with sagittal imaging of temporomandibular joint (TMJ), CLPM images and most of the oblique sagittal imaging were able to show the LPM clearly. Hypertrophy, atrophy and contracture of the LPM were found in TMJs either with disc in normal position or with disc displacements. Pathological changes of the superior belly and hypertrophy of the inferior belly combined with various pathological changes of the superior belly were the most frequently observed abnormal imaging findings of the LPM in TMD. The pathological changes of the LPM were associated with the main clinical symptoms of TMD. In patients with symptomatic condyle hypermobility, the pathological changes of the LPM and related symptoms were associated with the clinical symptoms of TMJs with disc in normal position. The imaging abnormalities of the LPM were common in TMJs with disc displacements and seemed to be fewer in condyle hypomobility cases in TMJs with anterior disc displacement with non-reduction (ADDnr). However, normal imaging of the LPM was also found in TMJs with severe osteoarthritic changes and disc displacement. The recognition of muscle alterations may lead to a more specific diagnosis and improve the understanding of the clinical symptoms and disease pathophysiology of TMD.