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Skeletal alterations in the head and neck region, such as midfacial hypoplasia, foramen magnum stenosis and spinal canal stenosis, are commonly observed in patients with mucopolysaccharidosis (MPS). However, enzyme replacement therapy (ERT), one of the major treatment approaches for MPS, shows limited efficacy for skeletal conditions. In this study, we analysed the craniofacial morphology of mice with MPS type VII, and investigated the underlying mechanisms promoting jaw deformities in these animals. Furthermore, we investigated the effects of C-type natriuretic peptide (CNP), a potent endochondral ossification promoter, on growth impairment of the craniofacial region in MPS VII mice when administered alone or in combination with ERT. MPS VII mice exhibited midfacial hypoplasia caused by impaired endochondral ossification, and histological analysis revealed increased number of swelling cells in the resting zone of the spheno-occipital synchondrosis (SOS), an important growth centre for craniomaxillofacial skeletogenesis. We crossed MPS VII mice with transgenic mice in which CNP was expressed in the liver under the control of the human serum amyloid-P component promoter, resulting in elevated levels of circulatory CNP. The maxillofacial morphological abnormalities associated with MPS VII were ameliorated by CNP expression, and further prevented by a combination of CNP and ERT. Histological analysis showed that ERT decreased the swelling cell number, and CNP treatment increased the width of the proliferative and hypertrophic zones of the SOS. Furthermore, the foramen magnum and spinal stenoses observed in MPS VII mice were significantly alleviated by CNP and ERT combination. These results demonstrate the therapeutic potential of CNP, which can be used to enhance ERT outcome for MPS VII-associated head and neck abnormalities.

X-ray-induced acoustic computed tomography (XACT) is a unique hybrid imaging modality that combines high X-ray absorption contrast with high ultrasonic resolution. X-ray radiography and computerized tomography (CT) are currently the gold standards for 2-D and 3-D imaging of skeletal tissues though there are important properties of bone, such as elasticity and speed of sound (SOS), that these techniques cannot measure. Ultrasound is capable of measuring such properties though current clinical ultrasound scanners cannot be used to image the interior morphology of bones because they fail to address the complicated physics involved for exact image reconstruction; bone is heterogeneous and composed of layers of both cortical and trabecular bone, which violates assumptions in conventional ultrasound imaging of uniform SOS. XACT, in conjunction with the time-reversal algorithm, is capable of generating precise reconstructions, and by combining elements of both X-ray and ultrasound imaging, XACT is potentially capable of obtaining more information than any single of these techniques at low radiation dose. This article highlights X-ray-induced acoustic detection through linear scanning of an ultrasound transducer and the time-reversal algorithm to produce the first-ever XACT image of a bone sample. The results of this study should prove to enhance the potential of XACT imaging in the evaluation of bone diseases for future clinical use.

Ultra-short echo time (UTE) MRI with post-processing is a promising technique in bone imaging that produces a similar contrast to computed tomography (CT). Here, we propose a 3D slab-selective ultrashort echo time (UTE) sequence together with image post-processing to image bone structures in the lumbar spine. We also explore the intermodality agreement between the UTE and CT images. The lumbar spines of two healthy volunteers were imaged with 3D UTE using five different resolutions to determine the best imaging protocol. Then, four patients with low back pain were imaged with both the 3D UTE sequence and CT to investigate agreement between the imaging methods. Two other patients with low back pain were then imaged with the 3D UTE sequence and clinical conventional T1-weighted and T2-weighted fast spin-echo (FSE) MRI sequences for qualitative comparison. The 3D UTE sequence together with post-processing showed high contrast images of bone and high intermodality agreement with CT images. In conclusion, post-processed slab-selective UTE imaging is a feasible approach for highlighting bone structures in the lumbar spine and demonstrates significant anatomical correlation with CT images.

The origin of terrestrial tetrapods was a key event in vertebrate evolution, yet how and when it occurred remains obscure, due to scarce fossil evidence. Here, we show that the study of palaeopathologies, such as broken and healed bones, can help elucidate poorly understood behavioural transitions such as this. Using high-resolution finite element analysis, we demonstrate that the oldest known broken tetrapod bone, a radius of the primitive stem tetrapod Ossinodus pueri from the mid-Viséan (333 million years ago) of Australia, fractured under a high-force, impact-type loading scenario. The nature of the fracture suggests that it most plausibly occurred during a fall on land. Augmenting this are new osteological observations, including a preferred directionality to the trabecular architecture of cancellous bone. Together, these results suggest that Ossinodus, one of the first large (>2m length) tetrapods, spent a significant proportion of its life on land. Our findings have important implications for understanding the temporal, biogeographical and physiological contexts under which terrestriality in vertebrates evolved. They push the date for the origin of terrestrial tetrapods further back into the Carboniferous by at least two million years. Moreover, they raise the possibility that terrestriality in vertebrates first evolved in large tetrapods in Gondwana rather than in small European forms, warranting a re-evaluation of this important evolutionary event.

Diagnosis of new bone growth in patients with compound tibia fractures or deformities treated using a Taylor spatial frame is difficult with conventional radiography because the frame obstructs the images and creates artifacts. The use of Na(18)F PET studies may help to eliminate this difficulty. METHODS: Patients were positioned on the pallet of a clinical PET/CT scanner and made as comfortable as possible with their legs immobilized. One bed position covering the site of the fracture, including the Taylor spatial frame, was chosen for the study. A topogram was performed, as well as diagnostic and attenuation correction CT. The patients were given 2 MBq of Na(18)F per kilogram of body weight. A 45-min list-mode acquisition was performed starting at the time of injection, followed by a 5-min static acquisition 60 min after injection. The patients were examined 6 wk after the Taylor spatial frame had been applied and again at 3 mo to assess new bone growth. RESULTS: A list-mode reconstruction sequence of 1 × 1,800 and 1 × 2,700 s, as well as the 5-min static scan, allowed visualization of regional bone turnover. CONCLUSION: With Na(18)F PET/CT, it was possible to confirm regional bone turnover as a means of visualizing bone remodeling without the interference of artifacts from the Taylor spatial frame. Furthermore, dynamic list-mode acquisition allowed different sequences to be performed, enabling, for example, visualization of tracer transport from blood to the fracture site., QC 20150629

Many applications in medical research and development require virtual three dimensional (3D) models of bones. The current gold standard for the acquisition of such data is Computer Tomography (CT) scanning. Due to the amount of radiation involved, CT scanning is generally limited to the imaging of clinical cases and cadaver specimens [Messmer, 2007]. Magnetic Resonance Imaging (MRI) is not routinely used for the imaging of bones because of difficulties in precise segmentation between bone and certain soft tissue types as well as higher costs compared to CT. As MRI does not involve ionising radiation it is ideally suited for the imaging of volunteers, who can be recruited according to study specific requirements. This study aimed to develop a MRI scanning protocol suitable to image the legs of volunteers and to provide an initial validation of the geometrical accuracy of the reconstructed 3D models.

The typical giant cell tumor (GCT) is a solitary neoplams that occurs in the epiphysis or epimetaphysis of long bones. GCT is seen with a slightly increased frequency in females, and 70% of patients are between 20 and 40 years of age at the time of presentation. Multicentric giant cell tumor (MGCT; two or more centers) is an unusual variant of GCT. Patients with MGCT are likely to be younger than those with a solitary lesion. The multicentric variety is often of a higher stage at diagnosis and is more often associated with a pathological fracture than the unifocal tumor. We are reporting five new cases of MGCT, with a total of 21 tumors seen over a period of 25 years from 1967 to 1992.

The typical giant cell tumor (GCT) is a solitary neoplams that occurs in the epiphysis or epimetaphysis of long bones. GCT is seen with a slightly increased frequency in females, and 70% of patients are between 20 and 40 years of age at the time of presentation. Multicentric giant cell tumor (MGCT; two or more centers) is an unusual variant of GCT. Patients with MGCT are likely to be younger than those with a solitary lesion. The multicentric variety is often of a higher stage at diagnosis and is more often associated with a pathological fracture than the unifocal tumor. We are reporting five new cases of MGCT, with a total of 21 tumors seen over a period of 25 years from 1967 to 1992.