Accurate cerebral blood flow (CBF) quantification is essential to diagnose and treat many cerebrovascular diseases, including Moyamoya, carotid stenosis, and stroke. The gold standard for CBF (oxygen-15 water positron emission tomography, PET) is not widely available because of its high cost, use of ionizing radiation, and logistical challenges as compared to magnetic resonance imaging (MRI). In this study, using simultaneous PET/MRI, we propose a multi-task learning framework for brain MRI-to-PET translation and disease classification. The proposed framework comprises two prime networks: (1) an attention-based 3D convolutional encoder-decoder network to synthesize high-quality PET CBF maps from multi-contrast MRI images, and (2) a multi-scale 3D convolutional network to identify the brain disease corresponding to the input MRI images. Our multi-task framework yields promising results on the task of MRI-to-PET translation, achieving an average structural similarity index of 0.94 and peak signal-to-noise ratio of 38dB on a cohort of 120 subjects. In addition, we show that integrating multiple MRI modalities can improve the clinical diagnosis of brain diseases. As such, deep learning offers the possibility to perform high-quality CBF measurements and disease classification for patients with cerebrovascular disease at MRI-only sites, leading to improved and more equitable patient care.
Plantar pressure measurements can provide valuable insight into various health characteristics in patients. In this study, we describe different plantar pressure devices available on the market and their clinical relevance. Current devices are either platform-based or wearable and consist of a variety of sensor technologies: resistive, capacitive, piezoelectric, and optical. The measurements collected from any of these sensors can be utilized for a range of clinical applications including patients with diabetes, trauma, deformity and cerebral palsy, stroke, cervical myelopathy, ankle instability, sports injuries, and Parkinsons disease. However, the proper technology should be selected based on the clinical need and the type of tests being performed on the device. In this review we provide the reader with a simple overview of the existing technologies their advantages and disadvantages and provide application examples for each. Moreover, we suggest new areas in orthopaedic that plantar pressure mapping technology can be utilized for increased quality of care.
Study Design: Retrospective Cohort Objective: This study seeks to establish the normal distribution of the vasculature surrounding the SI joint while also demonstrating associations between distribution and laterality, sex, and ethnicity. Summary of Background Data: Sacroiliac (SI) joint fusion surgery has emerged as a viable treatment option for patients suffering from low back pain due to chronic SI joint dysfunction. Due to potential complications from iatrogenic injury to vasculature, it becomes critical to understand normal anatomy and locations with a high vasculature concentration surrounding the SI joint. Methods: The authors retrieved medical and radiographic records of patients who underwent computed tomography angiography (CTA) of the pelvis. Anterior and posterior compartments of the SI joint were established on the transverse view by creating an even coronal division of the SI joint. The superior, middle, and inferior compartments were established on the coronal view as three equal transverse compartments. The compartments in which vasculature was visualized were recorded. Results: Distribution of vasculature around the right and left hemipelvis concentrated in the inferior compartments and decreased in concentration while moving superiorly. Anterior compartments contain a higher vascularity than posterior compartments. Vasculature was present in less than 3% of the posterior middle, and posterior superior compartments while present in more than 83% of the inferior compartments. There were no significant differences with respect to vascular distribution when comparing the laterality of the right versus left hemipelvis. There were statistically significant relationships between vascular distribution and sex ( P <0.05), as well as across self-reported ethnicity ( P <0.05). Conclusion: SI screw placement in the posterior superior has the lowest risk of iatrogenic vascular injury. Careful consideration should be taken during SI joint fusion surgery in the inferior compartments due to its high vasculature density.
Intussusception in adults is a rare occurrence at approximately 5% and malignancy as the cause comprises half that number. The most common malignancies found are primary adenocarcinoma, metastatic carcinoma, lymphoma, and gastrointestinal stromal tumors. Lymphoma is the second most common. The management of adult intussusception is generally surgical, which is due to the higher likelihood of malignancy being the underlying cause. The patient's history helps to direct management and the most likely underlying diagnosis. This is especially important in patients who are immunosuppressed and with a history of lymphoproliferative disease. Early management and proper surgical intervention allow for the best survival rate. Here we present a case of adult intussusception caused by a rare and aggressive type of non-Hodgkin lymphoma.
<div>AbstractPurpose:<p>Immunotherapy has been demonstrably effective against multiple cancers, yet tumor escape is common. It remains unclear how brain tumors escape immunotherapy and how to overcome this immune escape.</p>Experimental Design:<p>We studied KR158B-luc glioma-bearing mice during treatment with adoptive cellular therapy (ACT) with polyclonal tumor-specific T cells. We tested the immunogenicity of primary and escaped tumors using T-cell restimulation assays. We used flow cytometry and RNA profiling of whole tumors to further define escape mechanisms. To treat immune-escaped tumors, we generated escape variant-specific T cells through the use of escape variant total tumor RNA and administered these cells as ACT. In addition, programmed cell death protein-1 (PD-1) checkpoint blockade was studied in combination with ACT.</p>Results:<p>Escape mechanisms included a shift in immunogenic tumor antigens, downregulation of MHC class I, and upregulation of checkpoint molecules. Polyclonal T cells specific for escape variants displayed greater recognition of escaped tumors than primary tumors. When administered as ACT, these T cells prolonged median survival of escape variant-bearing mice by 60%. The rational combination of ACT with PD-1 blockade prolonged median survival of escape variant glioma-bearing mice by 110% and was dependent upon natural killer cells and T cells.</p>Conclusions:<p>These findings suggest that the immune landscape of brain tumors are markedly different postimmunotherapy yet can still be targeted with immunotherapy.</p></div>
Accurate quantification of cerebral blood flow (CBF) is essential for the diagnosis and assessment of cerebrovascular diseases such as Moyamoya, carotid stenosis, aneurysms, and stroke. Positron emission tomography (PET) is currently regarded as the gold standard for the measurement of CBF in the human brain. PET imaging, however, is not widely available because of its prohibitive costs, use of ionizing radiation, and logistical challenges, which require a co-localized cyclotron to deliver the 2 min half-life Oxygen-15 radioisotope. Magnetic resonance imaging (MRI), in contrast, is more readily available and does not involve ionizing radiation. In this study, we propose a multi-task learning framework for brain MRI-to-PET translation and disease diagnosis. The proposed framework comprises two prime networks: (1) an attention-based 3D encoder-decoder convolutional neural network (CNN) that synthesizes high-quality PET CBF maps from multi-contrast MRI images, and (2) a multi-scale 3D CNN that identifies the brain disease corresponding to the input MRI images. Our multi-task framework yields promising results on the task of MRI-to-PET translation, achieving an average structural similarity index (SSIM) of 0.94 and peak signal-to-noise ratio (PSNR) of 38dB on a cohort of 120 subjects. In addition, we show that integrating multiple MRI modalities can improve the clinical diagnosis of brain diseases.
