Isogeometric Analysis of Hyperelastic Material Characteristics for Calcified Aortic Valve

This study explores the implementation of computed tomography(CT)reconstruction and simulation techniques for patient-specific valves,aiming to dissect the mechanical attributes of calcified valves within transcatheter heart valve replacement(TAVR)procedures.In order to facilitate this exploration,it derives pertinent formulas for 3D multi-material isogeometric hyperelastic analysis based on Hounsfield unit(HU)values,thereby unlocking foundational capabilities for isogeometric analysis in calcified aortic valves.A series of uniaxial and biaxial tensile tests is executed to obtain an accurate constitutive model for calcified active valves.To mitigate discretization errors,methodologies for reconstructing volumetric parametric models,integrating both geometric and material attributes,are introduced.Applying these analytical formulas,constitutive models,and precise analytical models to isogeometric analyses of calcified valves,the research ascertains their close alignment with experimental results through the close fit in displacement-stress curves,compellingly validating the accuracy and reliability of the method.This study presents a step-by-step approach to analyzing themechanical characteristics of patient-specific valves obtained fromCT images,holding significant clinical implications and assisting in the selection of treatment strategies and surgical intervention approaches in TAVR procedures.

Nucleus Pulposus Cells from Calcified Discs Promote the Degradation of the Extracellular Matrix through Upregulation of the GATA3 Expression

Objective Disc calcification is strongly associated with disc degeneration;however,the underlying mechanisms driving its pathogenesis are poorly understood.This study aimed to provide a gene expression profile of nucleus pulposus cells(NPCs)from calcified discs,and clarify the potential mechanism in disc degeneration.Methods Primary NPCs were isolated from calcified and control discs(CAL-NPC and CON-NPC),respectively.The proliferation and extracellular matrix(ECM)metabolism capacities of the cells were evaluated using MTT and Western blotting,respectively.RNA sequencing was used to identify differentially expressed genes(DEGs)in the CAL-NPCs.The biological functions of the DEGs were analyzed using the Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)databases.The transcription factor database and Cytoscape software were used to construct the transcription factor-DEGs regulatory network.The role of the verified transcription factor in NPC proliferation and ECM metabolism was also investigated.Results The CAL-NPCs exhibited a lower proliferation rate and higher ECM degradation capacity than the CON-NPCs.In total,375 DEGs were identified in the CAL-NPCs.The GO and KEGG analyses showed that the DEGs were primarily involved in the regulation of ribonuclease activity and NF-kappa B and p53 signaling pathways.GATA-binding protein 3(GATA3)with the highest verified levels was selected for further studies.Overexpression of GATA3 in the CON-NPCs significantly inhibited their proliferation and promoted their ECM degradation function,while the knockdown of GATA3 in the CAL-NPCs resulted in the opposite phenotypes.Conclusion This study provided a comprehensive gene expression profile of the NPCs from the calcified discs and supported that GATA3 could be a potential target for reversing calcification-associated disc degeneration.

Ankle and toe weakness caused by calcified ligamentum flavum cyst: A case report

BACKGROUND Ligamentum flavum cysts,which are most common in mobile junctional levels of the spine,can be a rare cause of spinal stenosis.There have been several case reports of ligamentum flavum cysts.However,there is yet to be a documented case report of a calcified ligamentum flavum cyst.Herein,we report the first case of a calcified ligamentum flavum cyst causing ankle and toe weakness.CASE SUMMARY A 66-year-old male visited our hospital complaining of claudication as well as thigh and calf pain in his left leg,all beginning two weeks prior.Physical examination revealed motor weakness of the left ankle dorsiflexion and great toe dorsiflexion.Lumbar spinal computed tomography scans showed spinal stenosis combined with a calcified mass at the left side of the L4-5 level.Magnetic reso-nance imaging showed dural sac compression caused by the calcified mass at the left ligamentum flavum of the L4-5 level.We performed decompressive laminectomy and excision of the calcified mass combined with posterior lumbar interbody fusion at the L4-5 level.Intra-operatively,we found a firm and nodule like mass originating from the ventral surface of ligamentum flavum.Pathological examination suggested a calcified pseudocyst without a capsular lining.After the operation,the patient’s motor weakness in the ankle and great toe improved gradually.CONCLUSION The patient’s ankle and great toe weakness were improved successfully after surgical removal of the calcified cyst.

Automatic Calcified Plaques Detection in the OCT Pullbacks Using Convolutional Neural Networks

Background Coronary artery calcification is a well-known marker of atherosclerotic plaque burden.High-resolution intravascular optical coherence tomography(OCT)imaging has shown the potential to characterize the details of coronary calcification in vivo.In routine clinical practice,it is a time-consuming and laborious task for clinicians to review the over 250 images in a single pullback.Besides,the imbalance label distribution within the entire pullbacks is another problem,which could lead to the failure of the classifier model.Given the success of deep learning methods with other imaging modalities,a thorough understanding of calcified plaque detection using Convolutional Neural Networks(CNNs)within pullbacks for future clinical decision was required.Methods All 33 IVOCT clinical pullbacks of 33 patients were taken from Affiliated Drum Tower Hospital,Nanjing University between December 2017 and December 2018.For ground-truth annotation,three trained experts determined the type of plaque that was present in a B-Scan.The experts assigned the labels'no calcified plaque','calcified plaque'for each OCT image.All experts were provided the all images for labeling.The final label was determined based on consensus between the experts,different opinions on the plaque type were resolved by asking the experts for a repetition of their evaluation.Before the implement of algorithm,all OCT images was resized to a resolution of 300×300,which matched the range used with standard architectures in the natural image domain.In the study,we randomly selected 26 pullbacks for training,the remaining data were testing.While,imbalance label distribution within entire pullbacks was great challenge for various CNNs architecture.In order to resolve the problem,we designed the following experiment.First,we fine-tuned twenty different CNNs architecture,including customize CNN architectures and pretrained CNN architectures.Considering the nature of OCT images,customize CNN architectures were designed that the layers were fewer than 25 layers.Then,three with good performance were selected and further deep fine-tuned to train three different models.The difference of CNNs was mainly in the model architecture,such as depth-based residual networks,width-based inception networks.Finally,the three CNN models were used to majority voting,the predicted labels were from the most voting.Areas under the receiver operating characteristic curve(ROC AUC)were used as the evaluation metric for the imbalance label distribution.Results The imbalance label distribution within pullbacks affected both convergence during the training phase and generalization of a CNN model.Different labels of OCT images could be classified with excellent performance by fine tuning parameters of CNN architectures.Overall,we find that our final result performed best with an accuracy of 90%of'calcified plaque'class,which the numbers were less than'no calcified plaque'class in one pullback.Conclusions The obtained results showed that the method is fast and effective to classify calcific plaques with imbalance label distribution in each pullback.The results suggest that the proposed method could be facilitating our understanding of coronary artery calcification in the process of atherosclerosis andhelping guide complex interventional strategies in coronary arteries with superficial calcification.

Excimer laser coronary atherectomy for a severe calcified coronary ostium lesion:A case report

BACKGROUND Percutaneous coronary intervention can be challenging for ostial coronary artery lesions due to calcium burden and elastic fiber content.Excimer laser coronary atherectomy(ELCA)is a less common treatment for severe calcified coronary ostium lesions.CASE SUMMARY An 81-year-old male presented to the Cardiology Department of Qingdao Municipal Hospital with a 1-year history of chest pain.Coronary angiography showed severe calcific stenosis(approximately 90%)in the right coronary artery ostium.The right coronary artery ostium was unable to be advanced using a 2.5 mm×12.0 mm balloon(NC Sprinter,Medtronic,United States)or dilated using a 2.0 mm×12.0 mm balloon(Sprinter,Medtronic,United States).The patient underwent successful ELCA and balloon dilation of the calcified coronary ostium lesion.CONCLUSION ELCA appears to be a safe and effective treatment for the management of severe calcified coronary ostium lesions.

Calcified plaque: the Achilles' Heel of present computed tomography coronary angiography for the elderly?

Nine percent to 27% of cardiac catheterizations today showed either angiographic normal coronary arteries or minimal atherosclerosis. 1,2 Given the expense of cardiac catheterization and the desire to use this valuable resource for therapeutic rather than diagnostic purpose, there is a strong impetus to develop non-invasive means of accurately detecting significant coronary artery stenosis.……

Bone Mineral “Quality”: Differing Characteristics of Calcified Microsphere Populations at the Osteoporotic and Osteoarthritic Femoral Articulation Front

The mineral front consists of large populations of organically enshrouded calcified microspheres (filamentous clusters) about 1 micron in diameter and associated smaller numbers of variably dense nanospheres, 30 - 40 nm in diameter. The discrete objects persist and modulate in maturity, and may constitute a variable “qualitative” factor in the skeletal inorganic phase, exemplified by the biomechanically contrasting pathologies of osteoporosis (OP;fracture, low stress condition) and osteoarthritis (OA;non fracture, high stress condition). The aim was to compare the articulation front material for morphological and trace element diversity using fresh female femoral head discards (from Dewsbury District Hospital NHS Mid-Yorkshire Trust). These were prepared for histology of the cartilage/bone interface region by immersion in hydrazine hydrate to expose the anorganic mineral topography for microscopy and FEGSEM microanalysis. 1) Mineral microsphere morphology (compared to animals as arbitrary controls) suggested that calcified microspheres from OP (n = 19) tended to be small (0.5 - 0.7 microns), smooth and compacted;those from OA (n = 19) were large (0.5 - 4.0 microns), uneven and irregularly dispersed. Respective calcified nanospheres from OP were similarly smaller (30 - 50 nm) than those from OA (>100 nm). In subchondral bone a proportion of the filamentous microspheres had fused into a fine-textured phase in OP and a coarse-textured phase in OA. 2) Trace element analysis (compared to positive porcine Si and Mg and other peaks) suggested a diminution with mineral maturity, and also with age effecting OP and OA similarly, with minor differences detected between them. It was concluded that calcified objects constituting the inorganic phase vary regionally with age and in fracture and nonfracture, being diminished in size (not number) in weak OP and enlarged (compared to porcine control) in stronger OA, with Si or Mg “doping” diminishing with time, perhaps influencing their individual bioactivity and matrix dynamics.

Calcified Nodule Formation <i>in Vitro</i>Using Rat Mandibular Incisor Pulp Cells

One great advantage of bone marrow is that a large number of stem cells can be obtained. However, stem cells cannot be taken from the bone marrow of a patient for the purpose of regenerating teeth. In dental practice, it may not be practical to obtain mesenchymal stem cells for the regeneration of the tooth from iliac bone marrow, as in orthopedics. Therefore, establishment of a cell source for tooth regeneration is one of the important problems in the field of regenerative medicine. Although the isolation of undifferentiated mesenchymal stem cells or odontoblasts from dental pulp may be difficult, dental pulp may be a favorable source for stem cells to regenerate a tooth via tissue engineering. As a fundamental study for tooth regeneration, this study was performed in order to clarify the culture periods for proliferation and differentiation using rat dental pulp-derived cells. The results of this study were as follows: Primary culture of the dental pulp cells does not require a long period of time. However, for sufficient proliferation of dental pulp cells to form a calcified nodule in the secondary culture, a long culture period is required. Dexamethasone was essential for the formation of calcified nodules by dental pulp-derived cells. Calcified nodule formation by dental pulp-derived cells in vitro required more than one month. The duration of the secondary culture for the dental pulp-derived cells will be much longer.

Primitive Peritoneal Hydatic Calcified Cyst —A Case Report

It is a cosmopolitan disease, due to the embryonic shape of taenia of the dog Ecchinococcosis granulosis. The peritoneal hydatidosis is the sowing of this serous in a primitive or secondary way. It can be caused by the massive break of a visceral hydatid cyst realizing the anaphylactic shock. Somewhere else, the discreet fissuring is the most usual realizing peritoneum cysts. So the peritoneal hydatidosis appears under polymorphic clinical painting according to the anatomical location of cysts. The disease puts a real problem of public health in our country. The primitive peritoneal localization is rare. We report a case of a primitive intra-peritoneal hydatid cyst.

A 20-Year-Old Contraceptive Device Transformed into a Calcified Mass

Case: A 52-year-old female who was presented to accident and emergency felt unwell;she reported that she had an IUCD inserted over 20 years ago. On examination she had a large calcified mass occupying the vagina. CT scan confirmed a calcified IUCD. Conclusion: Serious complication secondary to IUCD is rare but well recorded, extensive calcification as in this case is very rare and has not been previously reported.

Calcified Chronic Subdural Haematoma Mimic Meningioma

Background: The calcified chronic subdural haematoma is rare. The first case description is in 1884 [1]. The incidence of calcified chronic subdural haematoma has been reported to be 0.3% to 2.7% of all chronic subdural haematoma. Case Description: We reported a case of 27 year-old male presenting with deterioration of motor function in his right limbs since 1 month before admission, and brain imaging C-T scan and MRI were done;pathological lesion was successfully and completely removed, with good improvement post-surgery.

A Giant Calcified Subdural Empyema, a Complication of Ventriculo Peritoneal Shunt: Surgical Management and Revue of Literature

Subdural empyema is not a usual complication of ventriculo peritoneal shunt and the discovery of his calcified form is much exceptional in young adults. We report the case of a female patient of 17 years old carrying a shunt since 16 years who was received for retro auricular suppuration facing the intra ventricular drain and whom cerebral CT-Scan shows a right hemispheric calcified empyema. A large craniotomy was realized in the same time than an external ventricular drain. Evolution was marked by minor right body motor troubles and seizures. Difficulties we have faced during the management are a reminder about morbidity due to the insertion of a ventriculo peritoneal shunt and the need of and long term follow up for the carriers.

Magnetic resonance imaging of the zone of calcified cartilage in the knee joint using 3-dimensional ultrashort echo time cones sequences

Background: The zone of calcified cartilage (ZCC) plays an important role in the pathogenesis of osteoarthritis (OA) but has never been imaged in vivo with magnetic resonance (MR) imaging techniques. We investigated the feasibility of direct imaging of the ZCC in both cadaveric whole knee specimens and in vivo healthy knees using a 3-dimensional ultrashort echo time cones (3D UTE-Cones) sequence on a clinical 3T scanner. Methods: In all, 12 cadaveric knee joints and 10 in vivo healthy were collected. At a 3T MR scanner with an 8-channel knee coil, a fat-saturated 3D dual-echo UTE-Cones sequence was used to image the ZCC, following with a short rectangular pulse excitation and 3D spiral sampling with conical view ordering. The regions of interests (ROIs) were delineated by a blinded observer. Singlecomponent T2* and T2 values were calculated from fat-saturated 3D dual-echo UTE-Cones and a Carr-Purcell-Meiboom-Gill (T2 CPMG) data using a semi-automated MATLAB code. Results: The single-exponential fitting curve of ZCC was accurately obtained with R2 of 0.989. For keen joint samples, the ZCC has a short T2* ranging from 0.62 to 2.55 ms, with the mean ±standard deviation (SD) of 1.49 ±0.66 ms, and with 95% confidence intervals (CI) of 1.20-1.78 ms. For volunteers, the short T2* ranges from 0.93 to 3.52ms, with the mean±SD of 2.09±0.56 ms, and the 95% CI is 1.43 to 2.74ms in ZCC. Conclusions: The high-resolution 3D UTE-Cones sequence might be used to directly image ZCC in the human knee joint on a clinical 3T scanner with a scan time of more than 10 min. Using this non-invasive technique, the T2* relaxation time of the ZCC can be further detected.

Detection of Repair of the Zone of Calcified Cartilage with Osteoarthritis through Mesenchymal Stem Cells by Ultrashort Echo Time Magnetic Resonance Imaging

Objective：Currently,magnetic resonance imaging （MRI） is the most commonly used imaging modality for observing the growth and development of mesenchymal stem cells （MSCs） after in vivo transplantation to treat osteoarthritis （OA）.However,it is a challenge to accurately monitor the treatment effects of MSCs in the zone of calcified cartilage （ZCC） with OA.This is especially true in the physiological and biochemical views that are not accurately detected by MRI contrast agents.In contrast,ultrashort time echo （UTE） MRI has been shown to be sensitive to the presence of the ZCC,creating the potential for more effectively observing the repair of the ZCC in OA by MSCs.A special focus is given to the outlook of the use ofUTE MRI to detect repair of the ZCC with OA through MSCs.The limitations of the current techniques for clinical applications and future directions are also discussed.Data Sources：Using the combined keywords：＂osteoarthritis＂,＂mesenchymal stem cells＂,＂calcified cartilage＂,and ＂magnetic resonance imaging＂,the PubMed/MEDLINE literature search was conducted up to June 1,2017.Study Selection：A total of 132 published articles were initially identified citations.Of the 132 articles,48 articles were selected after further detailed review.This study referred to all the important English literature in full.Results：In contrast,UTE MRI has been shown to be sensitive to the presence of the ZCC,creating the potential for more effectively observing the repair of the ZCC in OA by MSCs.Conclusions：The current studies showed that the ZCC could be described in terms of its histomorphology and biochemistry by UTE MRI.We prospected that UTE MRI has been shown the potential for more effectively observing the repair of the ZCC in OA by MSCs in vivo.

BMSCs-assisted injectable Col I hydrogel-regenerated cartilage defect by reconstructing superficial and calcified cartilage

The self-healing capacity of cartilage was limited due to absence of vascular,nervous and lymphatic systems.Although many clinical treatments have been used in cartilage defect repair and shown a promising repair result in short term,however,regeneration of complete zonal structure with physiological function,reconstruction cartilage homeostasis and maintaining long-term repair was still an unbridgeable chasm.Cartilage has complex zonal structure and multiple physiological functions,especially,superficial and calcified cartilage played an important role in keeping homeostasis.To address this hurdle of regenerating superficial and calcified cartilage,injectable tissue-induced type I collagen(Col I)hydrogel-encapsulated BMSCs was chosen to repair cartilage damage.After 1 month implantation,the results demonstrated that Col I gel was able to induce BMSCs differentiation into chondrocytes,and formed hyaline-like cartilage and the superficial layer with lubrication function.After 3 months post-surgery,chondrocytes at the bottom of the cartilage layer would undergo hypertrophy and promote the regeneration of calcified cartilage.Six months later,a continuous anatomical tidemark and complete calcified interface were restored.The regeneration of neo-hyaline cartilage was similar with adjacent normal tissue on the thickness of the cartilage,matrix secretion,collagen type and arrangement.Complete multilayer zonal structure with physiological function remodeling indicated that BMSCs-assisted injectable Col I hydrogel could reconstruct cartilage homeostasis and maintain long-term therapeutic effect.

Endoscopic resection for calcifying fibrous tumors of the gastrointestinal tract

BACKGROUND Calcifying fibrous tumors(CFTs)are rare mesenchymal lesions that can occur in various sites throughout the body,including the tubular gastrointestinal(GI)tract.AIM To analyze the clinical findings of 36 patients with GI tract CFTs to provide guidance for diagnosis and treatment.METHODS This retrospective study included 36 patients diagnosed with CFTs of the GI tract.We collected demographic and clinical information and conducted regular follow-ups to assess for local recurrence.RESULTS The stomach was the most commonly involved site,accounting for 72.2%of the 36 CFTs.Endoscopic mucosal resection(n=1,2.8%),endoscopic submucosal dissection(n=14,38.9%),endoscopic full-thickness resection(n=16,44.4%),and submucosal tunneling endoscopic resection(n=5,13.9%)were used to resect calcifying fibrous tumors.Overall,34(94.4%)CFTs underwent complete endoscopic resections with a mean procedure time of 39.8±29.8 min.The average maximum diameter of the tumors was 10.6±4.3 cm.No complications,such as bleeding or perforation,occurred during an average hospital stay of 2.9±1.2 d.In addition,two patients developed new growth of CFTs near the primary tumor sites,and none of the patients developed distant metastases during the follow-up period.CONCLUSION GI tract CFTs are rare and typically benign tumors that can be effectively managed with endoscopic procedures.

Calcified chronic subdural hematoma: A case report and literature review

Calcified chronic subdural hematoma(CCSDH) is a rare disease that accounts for approximately 0.3%–2.7% of all chronic subdural hematomas(CSDHs). The clinical features of CCSDH are very similar to those of noncalcified CSDH and include headache,decreased alertness,weakness,numbness,gait disturbance,seizures,memory impairment,confusion,and unconsciousness. All symptomatic CCSDH should be treated surgically. Majority of these patients recover well following surgery. In this report,we present the case of a patient with CCSDH who developed severe cerebral edema following its removal,necessitating decompressive craniectomy. Although there were no abnormal findings in laboratory blood tests,and no signs of brain herniation or epilepsy was found the following day after surgery,the patient's family refused all treatment and a post-operative brain computed tomography(CT) scan. The patient was discharged and died at home. Cerebral hematoma and normal perfusion pressure breakthrough(NPPB) may cause severe cerebral edema following the total removal of a CCSDH.

Direct versus pre- dilated rotational atherectomy for treating calcified coronary lesions

Objective To compare the efficacy of direct and pre-dilated atherectomy(RA)for treating the patients with calcified coronary lesions.Methods A total of 137coronary artery disease(CAD)patients receiving RA treatment in our hospital from 2010-04 to 2014-09were retrospectively studied.The ischemic related

Bronchial glomus tumor with calcification: A case report

BACKGROUND Glomus tumors(GTs),defined by modified smooth cells and normal glomus body cells,usually present with a small mass occurring in the soft tissue or dermis of an extremity,especially in the subungual region.However,other unusual sites,such as the respiratory tract,have also been reported.They are usually sporadic.Their imaging findings are usually nonspecific and likely to appear as a well-delineated round mass that usually lacks calcification.To our knowledge,we report the first case of bronchial GTs with calcification,reminding clinicians and radiologists that GT is one of the differential diagnoses when a calcified nodular mass is found.CASE SUMMARY We report a case of a 33-yr-old Chinese man with cough and sputum for 11 d and hemoptysis for 5 d.Chest computed tomography revealed a calcified nodular lesion on the compressed posterior wall of the lower left main bronchus and bronchiectasis in the lower lobe of the left lung.To confirm the characteristics of calcified nodules,we performed fiberoptic bronchoscopy.The tumor tissue from the biopsy of bronchial mucosal lesions established the diagnosis of GT.Because the patient had no life-threatening symptoms,he was not treated with surgery.Clinical follow-up for 25 mo showed that the patient survived well without any discomfort.CONCLUSION Bronchial GTs are usually not accompanied by calcification on computed tomography scans.To our knowledge,we report the first calcified bronchial GT.We recommend that clinicians consider GT as a possible differential diagnosis when a calcified mass of the bronchi is found.

“One-man” bailout technique for high-speed rotational atherectomy——assisted percutaneous coronary intervention in an octogenarian

Heavily calcified coronary lesions continue to represent a challenge for percutaneous coronary intervention(PCI),as they are difficult to dilate,and it is difficult to deliver and implant drug-eluting stents(DES)properly.Poor stent deployment is associated with high rates of periprocedural complications and suboptimal long-term clinical outcomes.[1]Thanks to the introduction of several adjunctive PCI tools,like cutting and scoring balloons,and to the novel intravascular lithotripsy technology,the treatment of such lesions has become increasingly feasible,predictable and safe.