Assessment of Ultrasound Elastography for Orthopedic Applications

Ultrasound imaging is emerging as an attractive alternative modality to standard x-ray and CT methods for bone assessment applications. The high reflectivity at the bone/soft tissue interface that occurs due to high acoustic impedance mismatch presents an important diagnostic opportunity affording the detection of abnormalities at bone surfaces with high accuracy and contrast-to-noise ratios. Furthermore, the mechanical properties of the soft tissue surrounding the bones undergo changes depending on the integrity of the underlying bone, viz. intact, fractured or healing. Unlike other imaging modalities, ultrasound elastography techniques, with their sensitivity to variations in soft tissue stiffness, are able to assist with monitoring bone regrowth. However, there is presently a lack of systematic studies that investigate the performance of diagnostic ultrasound techniques in bone imaging applications. This dissertation aims at understanding the performance limitations of new ultrasound techniques for assessing intact and fractured bones in vitro as well as in vivo. Ultrasound based 2D, 3D and elastography imaging experiments were performed on in vitro and in vivo samples of mammalian as well as non-mammalian bones. Ultrasound measurements of controlled defects were statistically compared with those obtained from the same samples using alternate imaging modalities. The performance of axial strain elastograms and axial shear strain elastograms at the soft tissue/bone interface was also studied in intact and fractured bones, and statistical analysis was carried out using elastographic image quality tools. The results of this study demonstrate that it is feasible to use diagnostic ultrasound imaging techniques to assess bone defects in real time and with high accuracy and precision. The relative strength of the axial strains and the axial shear strains at the bone/soft tissue interface with respect to the background soft tissue reduce in the presence of a fracture. Consequently, the study concluded that a combination of these imaging modalities might provide information regarding the integrity of the underlying bone and also an insight into the severity of the fractures, alignment of bone fragments and the progress of bone healing. In the future, ultrasound imaging techniques might provide a cost-effective, real-time, safe and portable diagnostic tool for bone imaging applications

Real-time edge-enhanced optical correlator

The performance of five symbol lock detectors are compared. They are the square-law detector with overlapping (SQOD) and non-overlapping (SQNOD) integrators, the absolute value detectors with overlapping and non-overlapping (AVNOD) integrators and the signal power estimator detector (SPED). The analysis considers various scenarios when the observation interval is much larger or equal to the symbol synchronizer loop bandwidth, which has not been considered in previous analyses. Also, the case of threshold setting in the absence of signal is considered. It is shown that the SQOD outperforms all others when the threshold is set in the presence of signal, independent of the relationship between loop bandwidth and observation period. On the other hand, the SPED outperforms all others when the threshold is set in the presence of noise only

Molecular Branching Topology & Quantum Mechanical Quantities

183-18

Intensive sanitation project, Kamrup: an experience

Intensive sanitation project, Kamrup: an experienc

A praxis and Research Agenda for Multicultural Human Services Organizations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98268/1/1468-2397.00107.pd

A rare case of para-testicular dedifferentiated liposarcoma: a diagnostic dilemma

Paratesticular dedifferentiated liposarcoma (DD-LPS) are rare neoplasms. It has been estimated that 12% of DD-LPS occur in the paratesticular region, while the retroperitoneum is the most common site for this tumor. Herein, we presented a case of a 66-year-old male with a history of pedal edema and right scrotal swelling, CT scan shows a solid mass arising from the right side of the scrotum. Following this, a radical orchiectomy of the right testis with mass was performed, and after thorough microscopic and immunohistochemistry positive for MDM2 and CDK4, the diagnosis of low-grade dedifferentiated liposarcoma was given. This case report expands the morphologic spectrum of dedifferentiated liposarcoma and emphasizes the need to consider these tumours in the differential diagnosis of other neoplasms

BLDS Pressure Belt

Dr. Westphal has a Boundary Layer Data System (BLDS) that is used to take pressure measurements on the surface of the aircraft. Our team has created a design and manufacturing method for producing the corresponding pressure belt that attaches to Dr. Westphal\u27s system to obtain pressure data