29 research outputs found
Bone remodeling after MR imaging-guided high-intensity focused ultrasound ablation: evaluation with MR imaging, CT, Na(18)F-PET, and histopathologic examination in a swine model.
Bone remodeling following MR-guided focused ultrasound: Evaluation with HR-pQCT and FTIR.
Voriconazole-induced periostitis in two post-transplant patients.
While drug-related periostitis has been known of for many years, the specific association of diffuse periostitis with voriconazole (most frequently in transplant patients) has only been recently explicitly addressed in the literature. Recognition of the radiologic and clinical manifestations of voriconazole-related periostitis is important for helping to narrow an otherwise broad differential diagnosis. We present two cases that illustrate different radiologic presentations of this painful cause of diffuse periostitis. Case 1 features a 60 year-old woman with a history of orthotopic heart transplant who was hospitalized for "full body pain" with progressively worsening bone tenderness involving the humeri, knees, femurs, hips, and hands. Case 2 describes a 48 year-old man with a history of acute lymphoblastic leukemia status post stem cell transplant who presented with diffuse arthralgias involving bilateral ankles, knees, wrists, and elbows
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Bone remodeling following MR-guided focused ultrasound: Evaluation with HR-pQCT and FTIR.
Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel non-invasive ablation technique that uses focused sound energy to destroy focal tumors, primarily via heat deposition. It is widely used for palliation of pain from bone metastases and has also recently gained popularity as a technique for ablation of benign bone tumors and facet degenerative joint disease (rhizotomy). Clinically, in a subset of patients who have undergone MRgFUS of bone, a variety of treatment responses have been noted on follow-up imaging, including focal sclerosis within the target lesion or more exuberant proliferative changes associated with the periosteum. In this study, high resolution peripheral quantitative CT (HR-pQCT) was used to evaluate remodeling of bone following ablation in a swine model of MRgFUS and compared to samples from a control, non-treated femur. Within each treated femur, two lesions were created: a higher energy focused ultrasound dose was used for one lesion compared to a lower energy dose for the second lesion. Exuberant, extra-cortical bone formation was detected at the higher energy ablation zones, with volumes ranging from 340 mm3 to 1040 mm3. More subtle endosteal and cortical changes were detected in the lower energy ablation zones, however cortical thickness was significantly increased at these sites compared to control bone. For both high and low energy lesions, lower bone mineral density and tissue mineral density was noted in treated regions compared to control regions, consistent with the formation of newly mineralized tissue. Following HR-pQCT analysis, Fourier transform infrared (FTIR) spectroscopy was subsequently used to detect biochemical changes associated with remodeling of bone following MRgFUS, and compared to samples from the control, non-treated femur. Findings were compared with histopathologic examination following hematoxylin-eosin staining. FTIR analysis demonstrated lower mineral/phosphate ratio and increased crystallinity compared to the control samples (p = 0.013). Histopathologic review demonstrated associated areas of endosteal inflammation, scarring, fat necrosis, and new extra-cortical bone formation associated with the ablations. Overall, these findings provide novel characterization of new bone formation following MRgFUS ablation
The impact of technical parameters on ablation volume during MR-guided focused ultrasound of desmoid tumors
Bone Remodeling after MR Imaging–guided High-Intensity Focused Ultrasound Ablation: Evaluation with MR Imaging, CT, Na 18
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3D convolutional neural networks for detection and severity staging of meniscus and PFJ cartilage morphological degenerative changes in osteoarthritis and anterior cruciate ligament subjects.
BackgroundSemiquantitative assessment of MRI plays a central role in musculoskeletal research; however, in the clinical setting MRI reports often tend to be subjective and qualitative. Grading schemes utilized in research are not used because they are extraordinarily time-consuming and unfeasible in clinical practice.PurposeTo evaluate the ability of deep-learning models to detect and stage severity of meniscus and patellofemoral cartilage lesions in osteoarthritis and anterior cruciate ligament (ACL) subjects.Study typeRetrospective study aimed to evaluate a technical development.PopulationIn all, 1478 MRI studies, including subjects at various stages of osteoarthritis and after ACL injury and reconstruction.Field strength/sequence3T MRI, 3D FSE CUBE.AssessmentAutomatic segmentation of cartilage and meniscus using 2D U-Net, automatic detection, and severity staging of meniscus and cartilage lesion with a 3D convolutional neural network (3D-CNN).Statistical testsReceiver operating characteristic (ROC) curve, specificity and sensitivity, and class accuracy.ResultsSensitivity of 89.81% and specificity of 81.98% for meniscus lesion detection and sensitivity of 80.0% and specificity of 80.27% for cartilage were achieved. The best performances for staging lesion severity were obtained by including demographics factors, achieving accuracies of 80.74%, 78.02%, and 75.00% for normal, small, and complex large lesions, respectively.Data conclusionIn this study we provide a proof of concept of a fully automated deep-learning pipeline that can identify the presence of meniscal and patellar cartilage lesions. This pipeline has also shown potential in making more in-depth examinations of lesion subjects for multiclass prediction and severity staging.Level of evidence2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:400-410