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Pulmonary Bone Cement Embolism: CT Angiographic Evaluation with Material Decomposition Using Gemstone Spectral Imaging
摘要： We report a case of pulmonary bone cement embolism in a female who presented with dyspnea following multiple sessions of vertebroplasty. She underwent spectral CT pulmonary angiography and the diagnosis was made based on enhanced visualization of radiopaque cement material in the pulmonary arteries and a corresponding decrease in the parenchymal iodine content. Here, we describe the CT angiography findings of bone cement embolism with special emphasis on the potential benefits of spectral imaging, providing additional information on the material composition.
关键词： Bone cement,Spectral imaging,Pulmonary embolism,Dual-energy CT
更新于2025-09-23 15:21:01
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Reference Module in Biomedical Sciences || X-Ray Based Imaging Methods to Assess Bone Quality
摘要： Dual X-ray absorptiometry (DXA) is one of the best-researched quantitative imaging modalities in medicine. Its physical basis, technical features and limitations have been addressed in hundreds of papers and summarized in a report on bone densitometry of the International Commission on Radiation Units (ICRU) that also covers quantitative computed tomography (QCT) and describes performance measures used in densitometry (Kalender et al., 2009). The primary output of DXA is areal bone mineral density (aBMD). Its clinical relevance for the diagnosis of osteoporosis, fracture prediction, and monitoring of treatment and age related changes has been investigated in multiple very large epidemiological and pharmaceutical studies of more than 2,00,000 subjects worldwide. aBMD is the basis of the WHO working definition of osteoporosis (Kanis and WHO Study Group, 1994). It is a strong predictor of fracture risk, but even in combination with other risk factors it cannot predict whether an individual subject eventually will fracture or not. Today, about 50–100 patients with osteoporosis must be treated to prevent one fracture (Albert and Reddy, 2017); vice versa, about 50% subjects who fracture do not have osteoporosis (Schuit et al., 2004; Siris et al., 2004).
关键词： TBS,QCT,FEA,Bone Quality,Imaging Methods,X-Ray,HSA,DXA,HR-pQCT
更新于2025-09-23 15:21:01
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Indirect selective laser sintering printed microporous biphasic calcium phosphate scaffold promotes endogenous bone regeneration via activation of ERK1/2 signaling
摘要： Fabrication technique determines the physicochemical and biological properties of scaffold, including porosity, mechanical strength, osteoconductivity, and bone regenerative potential. Biphasic calcium phosphate (BCP)-based scaffolds are superior in bone tissue engineering due to their suitable physicochemical and biological properties. We developed an indirect selective laser sintering (SLS) printing strategy to fabricate 3D microporous BCP scaffolds for bone tissue engineering purposes. The green part of BCP scaffold was fabricated by SLS at relevantly low temperature in the presence of epoxy resin (EP) and the remaining EP was decomposed, and eliminated by a subsequent sintering process to obtain the microporous BCP scaffolds. Physicochemical properties, cell adhesion, biocompatibility, in vitro osteogenic potential and rabbit critical size cranial bone defect healing potential of the scaffolds were extensively evaluated. This indirect SLS printing eliminated the drawbacks of conventional direct SLS printing at high working temperatures, i.e., wavy deformation of the scaffold, hydroxyapatite decomposition, and conversion of β-TCP to α-TCP. Among the scaffolds printed with various binder ratios (by weight) of BCP and EP, the scaffold with 50/50 binder ratio (S4) showed the highest mechanical strength and porosity with the smallest pore size. Scaffold S4 showed the highest effect on osteogenic differentiation of precursor cells in vitro, and this effect was ERK1/2 signaling dependent. Scaffold S4 robustly promoted precursor cells homing, endogenous bone regeneration, and vascularization in rabbit critical-size cranial defect. In conclusion, BCP scaffold fabricated by indirect SLS printing maintains the physicochemical properties of BCP and possess the capacity to recruit host precursor cells to the defect site and promote the endogenous bone regeneration possibly via activation of ERK1/2 signaling.
关键词： endogenous bone regeneration,ERK1/2 signaling,biphasic calcium phosphate,selective laser sintering,bone tissue engineering
更新于2025-09-23 15:19:57
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Multiple miliary osteoma cutis treatment response to Q-switched Nd:YAG laser: A case report
摘要： Facial multiple miliary osteoma cutis is a variant of osteoma cutis usually occurring in women with a previous history of acne vulgaris. Successful ablative laser treatment has been reported using both CO2 and Er:YAG lasers among other invasive treatment modalities, like surgical removal. We report a patient with biopsy-proven facial multiple miliary osteoma cutis responding to non-ablative Q-switched Nd:YAG laser therapy. The patient had excellent cosmesis without textural changes or hypopigmentation despite her Asian background after three sessions over 6 months. Multiple miliary osteoma cutis is therefore now amenable to non-surgical non-ablative therapy by using Q-switched Nd:YAG laser therapy reducing the risk of textural changes and hypopigmentation, especially in dark complexion and high-risk individuals. To our knowledge, this treatment approach has not been previously reported.
关键词： non-ablative,laser,acne,Osteoma cutis,Nd:YAG,bone,skin,therapy
更新于2025-09-23 15:19:57
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A minimally invasive technique for serial intraosseous perfusion measurements in the murine tibia using laser Doppler flowmetry
摘要： In biomedical and preclinical research, the current standard method for measuring blood perfusion inside murine bone, radiolabeled microspheres, is a terminal procedure that cannot be used to monitor longitudinal perfusion changes. Laser Doppler ?owmetry (LDF) can assess perfusion within the proximal tibial metaphysis of mice in vivo but requires a surgical procedure to place the measurement probe directly onto the bone surface. Sustained in?ammation for over a month following this technique was previously reported, and previous studies have used LDF as an endpoint-only procedure. We developed a modi?ed, minimally invasive LDF procedure to measure intraosseous perfusion in the murine tibia without stimulating local or systemic in?ammation or inducing gait abnormalities. This modi?ed technique can be used to measure perfusion weekly for up to at least a month in the murine tibia.
关键词： Vascular supply,In vivo,Bone blood ?ow
更新于2025-09-23 15:19:57
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Is low level laser therapy or ozone therapy more effective for bone healing? Understanding the mechanisms of HIF-1?±, RANKL and OPG
摘要： Periodontitis is a common chronic infection of dental tissues. Ozone therapy (OT) and low level laser therapy (LLLT) are useful treatments for periodontitis. We investigated the effects of OT and LLLT on periodontal disease-induced bone destruction in rats with experimentally induced periodontitis (EP). We used 30 male Wistar rats divided into three groups: control, OT and LLLT. EP was induced by placing a 3.0 silk suture around the cervix of the left mandibular first molar tooth. OT was performed using an ozone generator at 80% concentration. LLLT was applied using a diode laser. Both OT and LLLT were performed for two weeks at two day intervals. Histomorphometric and immunohistochemical analyses also were performed. Alveolar bone loss was significantly less in the LLLT group compared to the control group. The number of HIF-1α positive cells was significantly less in the LLLT group compared to the control group. We found significantly fewer RANKL-positive cells in the OT group compared to the control group. The number of osteoprotegerin (OPG) positive cells was significantly greater for the LLLT group than for the control group. Although both treatments produced positive effects, LLLT appears to be more effective for increasing alveolar bone formation.
关键词： Bone healing,ozone therapy,RANKL,laser therapy,osteoprotegerin,periodontitis,rat,HIF-1α
更新于2025-09-23 15:19:57
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Silica/polycaprolactone Nanofiber Scaffold Variants for Human Periosteal Cell Growth
摘要： Polycaprolactone (PCL) nanofiber scaffolds with attached cadaveric human periosteum or its cells were investigated in this study as a tissue-engineering approach to repair non-union injuries of bone. Addition of silica nanoparticles (silica or nSiO2) to PCL scaffolds was examined for effects on the growth of human periosteal cells in vitro and in vivo. Electrospun PCL nanofiber (nanoPCL) scaffolds were fabricated with different silica content (0, 0.5 and 1.0 wt%) and utilized as substrates on which periosteal cells were seeded. Human periosteal cell growth analyzed in vitro over 21 days with a PrestoBlue? viability assay increased as a function of culture time on each of the three different silica/nanoPCL scaffolds. Cadaveric periosteum attached to nanoPCL scaffolds with or without silica was wrapped around allograft bone and implanted for 10 or 20 weeks in athymic (nude) mice. Histological and immunohistochemical analyses of these experiments in vivo confirmed the presence of viable cells populating the constructs after their retrieval from host mice. Osterix, a marker for osteoblasts, increased in retrieved constructs over time and indicated remodeling of the underlying allograft bone. Summary results suggest that silica/nanoPCL scaffolds may be utilized as substrates for periosteal cell and tissue expansion to augment and support clinical applications for treatment and healing of bone defects, including segmental bone injuries and non-unions.
关键词： nanoPCL,bone defects,silica,Periosteum,tissue engineering
更新于2025-09-23 15:19:57
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Precise differential diagnosis of acute bone marrow edema and hemorrhage and trabecular microfractures using na?ve and gamma correction pinhole bone scans
摘要： Objective: To analyze the performance of sequential na?ve pinhole bone scan (nPBS) and gamma correction pinhole bone scan (GCPBS), reinforced by ImageJ densitometry and pixelized micro-fracture measurement, for making specific diagnoses of bone marrow edema (BME), bone marrow hemorrhage (BMH), and trabecular microfractures (TMF). Methods: We prospectively examined BME, BMH, TMF, and normal trabeculae in 10 patients using sequential nPBS and GCPBS. The intensity of 99mtechnetium-hydroxydiphosphonate (99mTc-HDP) uptake was measured using a pixelized method and calculated using ImageJ densitometry in terms of arbitrary units (AU). This overall method was termed a visuospatial-mathematic assay (VSMA). We analyzed the ability of the calculated AU values to discriminate between the four states using GraphPad Prism software, with reference to previous morphological data. Results: The calculated values were categorized as ≤50 AU for normal trabecula, 51–100 AU for BME, 101–150 AU for BMH, and ≥151 AU for TMF. The difference in uptake between normal trabecula and BME was significant and the differences among BME, BMH, and TMF were highly significant. Conclusion: VSMA is a useful technique for refining objective individual diagnoses and for differentiating and quantitating BME, BMH, and TMF.
关键词： ImageJ densitometry,trabecular microfracture,bone marrow hemorrhage,bone marrow edema,visuospatial-mathematic assay,Bone scintigraphy
更新于2025-09-19 17:15:36
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Feasibility of three-dimensional reconstruction and automated measurement of fetal long bones using 5D Long Bone
摘要： To evaluate the feasibility of five-dimensional Long Bone (5D LB), a new technique that automatically archives, reconstructs images, and measures lengths of fetal long bones, to assess whether the direction of volume sweep influences fetal long bone measurements in three-dimensional (3D) ultrasound and 5D LB, and to compare measurements of fetal long bone lengths obtained with 5D LB and those obtained with conventional two-dimensional (2D) and manual 3D techniques.
关键词： Fetal biometry,Fetal long bone,Two-dimensional ultrasound,Three-dimensional ultrasound,5D Long Bone
更新于2025-09-19 17:15:36
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Improvements and reproducibility of an optimal grazing-incidence position method to L-shell x-ray fluorescence measurements of lead in bone and soft tissue phantoms
摘要： L-shell x-ray ?uorescence (LXRF) is a non-invasive approach to lead (Pb) concentration measurements in human bone. The method is based on the detection of the characteristic x-ray photons of Pb at 10.5 and 12.6 keV and experimental studies were designed to perform in vivo human bone Pb measurements. In later studies, however, the initial LXRF methodology was shown to have poor accuracy and precision. In a recent publication, we investigated an optimal grazing-incidence position (OGIP) approach using a sub-millimeter x-ray beam from an integrated x-ray tube and polycapillary x-ray lens table-top system. The OGIP method effectively reduced the x-ray scatter and produced a Pb detection limit of ～5 μg/g for a 2 mm soft tissue phantom thickness. In this study, the OGIP methodology was improved by using 10 s x-ray spectra acquisitions at sequential positions 0.5 mm apart. The measured Sr Kα peak height versus position data was used to spectroscopically identify the bone phantom and the OGIP. The data was ?tted with the analytical convolution between a Gaussian and an exponential decay. The position corresponding to the maximum of the ?tted convolution function was then selected as the OGIP. Four phantom sets were used. A cylindrical plaster-of-Paris bone phantom doped with Pb in a concentration of 74 μg/g was used as a bare bone phantom or with one of the three overlying polyoxymethylene cylindrical shell soft tissue phantoms of 1, 2, and 3 mm thickness. The reproducibility of the OGIP method was assessed in ?ve independent trials using each of the four phantom sets. The coef?cient of variation (COV) percentage values of the Sr Kα peak height measurements were below 5%. The new procedure decreased by more than threefold the duration and radiation dose of the earlier approach.
关键词： bone lead,reproducibility,LXRF
更新于2025-09-19 17:15:36