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1.
Quant Imaging Med Surg ; 14(2): 2060-2068, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38415160

RESUMO

The importance of virtual reality (VR) has been emphasized by many medical studies, yet it has been relatively under-applied to surgical operation. This study characterized how VR has been applied in clinical education and evaluated its tutorial utility by designing a surgical model of tumorous resection as a simulator for preoperative planning and medical tutorial. A 36-year-old male patient with a femoral tumor who was admitted to the Affiliated Jiangmen Traditional Chinese Medicine Hospital was randomly selected and scanned by computed tomography (CT). The data in digital imaging and communications in medicine (*.DICOM) format were imported into Mimics to reconstruct a femoral model, and were generated to the format of *.stl executing in the computer-aided design (CAD) software SenSable FreeForm Modeling (SFM). A bony tumor was simulated by adding clay to the femur, the procedure of tumorous resection was virtually performed with a toolkit called Phantom, and its bony defect was filled with virtual cement. A 3D workspace was created to enable the individual multimodality manipulation, and a virtual operation of tumorous excision was successfully carried out with indefinitely repeated running. The precise delineation of surgical margins was shown to be achieved with expert proficiency and inexperienced hands among 43 of 50 participants. This simulative educator presented an imitation of high definition, those trained by VR models achieved a higher success rate of 86% than the rate of 74% achieved by those trained by conventional methods. This tumorous resection was repeatably handled by SFM, including the establishment of surgical strategy, whereby participants felt that respondent force feedback was beneficial to surgical teaching programs, enabling engagement of learning experiences by immersive events which mimic real-world circumstances to reinforce didactic and clinical concepts.

2.
Psychol Aging ; 39(1): 1-13, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37883011

RESUMO

Happiness can be experienced differently in young as compared to older adulthood, possibly due to shifts in temporal focus and differences in preferences for high- versus low-arousal affective states. The current project aimed to replicate initial evidence on age-related differences in the experience of happiness by investigating the positive affective correlates of everyday happiness; we further explored the role of thinking about the future in moderating such associations. We used daily life assessments from 257 participants (Mage = 48.3, SDage = 24.6; 68% female; 77% Asian [East Asian, South Asian, and Southeast Asian]; 73% postsecondary educated), combining four data sets collected at two locations (Vancouver, Canada; Hong Kong) with different age samples (older and younger adults). Participants provided up to 30 repeated daily life assessments of momentary affective states and thoughts about the future, over 10 days. Results replicate previous findings by showing that happiness was more strongly associated with low-arousal positive affect and more weakly associated with high-arousal positive affect among older compared to younger adults. Engagement in thinking about the future was higher among younger compared to older adults in general, but its role in moderating the association between happiness and positive affect varying in arousal levels was confounded by the age moderation. Separate analyses conducted for each age group indicate different roles of everyday thinking about the future in shaping happiness experiences for different age groups. Age and future thinking-related contours of happiness are discussed in the context of emotional aging theories. (PsycInfo Database Record (c) 2024 APA, all rights reserved).


Assuntos
Envelhecimento , Felicidade , Idoso , Feminino , Humanos , Masculino , Envelhecimento/psicologia , Nível de Alerta , Povo Asiático , Emoções , Afeto
3.
Int J Med Robot ; 19(5): e2552, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37489032

RESUMO

OBJECTIVE: To design a virtual operation of joint replacement for surgical drills using a haptic device, SenSable_FreeForm_Modelling (SFM), to enhance surgeons' efficiency and enable "Virtual tutorial without reality" for interns. METHOD: A patient with hip joint osteoarthritis is randomly selected to perform Total Hip Replacement (THR). The hip images were input into Mimics in the format of *.dicom after CT scan and then exported to SFM using the stereolithographic (*.stl) format. A surgical toolkit can be created virtually with Computer Aided Design software such as Pro-E or Ghost SDK and a visual drill scenario of THR directed by a force-respondent stick, namely Phantom. RESULT: 3D models of the hip joint were rebuilt illustrating clearly that the geometrical shapes of the surgical equipment created are similar to real instruments, and the THR operation is emulated distinctly in novelty. CONCLUSION: In obedience to an ancient maxim, so called 'genuine knowledge originated from practice', this simulative operation offers hands-on experience for students in the orthopaedics field with remarkable effects, contributing not only teaching cases for medical courses but also a planning basis for physical surgery.


Assuntos
Artroplastia de Quadril , Osteoartrite do Quadril , Humanos , Imageamento Tridimensional/métodos , Interface Usuário-Computador , Software , Simulação por Computador , Artroplastia de Quadril/métodos , Osteoartrite do Quadril/diagnóstico por imagem , Osteoartrite do Quadril/cirurgia
4.
Int J Med Robot ; 17(6): e2323, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34405530

RESUMO

OBJECTIVE: This study attempts to analyse the biomechanical effect of internal fixation (plated in parallel or plated vertically) on the basis of distal humeral fractures on musculoskeletal multibody dynamics using AnyBody in Finite Element Method. METHOD: Humeral 3D models were reconstructed by MIMICS after volunteers' CT image input in *.dicom format, and processed by Geomagic Studio for surfaces, while locking plates and screws were then designed by Pro-E. A humeral model of T-type fracture was created and assembled in Hypermesh, to integrate fixtures (e.g., MPL/PML/ML), to grid the mesh and then assign materials. A musculoskeletal model of the upper limb was established by AnyBody to simulate elbow flexion and extension. They were finally imported to Abaqus for boundary conditions and dynamic analysis. RESULT: In terms of Von Mises stress, its maximum increased and then decreased gradually during the joint motion, but p > 0.05 in SPSS suggests no significant difference for all three fixtures. In terms of displacement, when the elbow was at 90°, each motional pattern reached its peak as follows: ML180° = 0.28 mm, MPL90° = 0.49 mm & PML90° = 0.54 mm during flexion; ML180° = 0.073 mm, MPL90° = 0.10 mm & PML90° = 0.12 mm during extension. p < 0.05 suggests a significant difference for the displacements of all three fixations. p = 0.007 < 0.01667 suggests the significant difference between the two fixations, for example, PML90° and ML180°, indicating that the peak displacement of ML180° is less than that of PML90°. CONCLUSION: After generally analysed in musculoskeletal dynamics, the biomechanical property of the fixtures was presented as follows: the displacement of the parallel plate was less than that of the vertical, and the parallel plate may optimise the clinical reduction anatomically.


Assuntos
Fraturas do Úmero , Fenômenos Biomecânicos , Placas Ósseas , Parafusos Ósseos , Análise de Elementos Finitos , Fixação Interna de Fraturas , Humanos , Fraturas do Úmero/cirurgia
5.
Int J Med Robot ; 17(6): e2321, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34390524

RESUMO

PURPOSE: Little is known about how biomechanics governs the biological nature for humeral motion dynamically. Elbow motion ought to be investigated based on a musculoskeletal model and evidence the physiologic principle of upper limbs. METHOD: A humeral model was reconstructed by MIMICS after CT images input in *.dicom format, it was processed by Geomagic Studio for Surfaces, then gridded mesh and assigned materials by Hypermesh. On the other hand, a musculoskeletal model was built by AnyBody, physical motions were then simulated to export boundary condition and myodynamia during flexion and extension. Finally, all the humeral model and boundary were imported to Abaqus for finite element analysis. RESULT: During the simulative motion of flexion, the primary muscles are brachii biceps, brachialis anticus and teretipronator, their myodynamia increased and then decreased gradually, and reached its peak value at 30°; During extension, the main muscles are triceps brachii and brachialis anticus, their myodynamia increased and then decreased gradually too, and reached peak at 50°; In these two cases, their strain and displacement distributed at the middle of humerus. CONCLUSION: AnyBody is a novel modelling system to simulate physical motion, for example flexion and extension. Biceps brachii and brachialis anticus are functional for flexion, and triceps brachii plays a key role in extension critically. This simulation confirms the physiologic rule for sport event, humeral fixation and postoperative healing with clinical significance that minimizing joint forces from injury onset may promote pain-free ways.


Assuntos
Articulação do Cotovelo , Braço , Fenômenos Biomecânicos , Humanos , Músculo Esquelético , Amplitude de Movimento Articular
7.
Comput Methods Programs Biomed ; 198: 105775, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33130494

RESUMO

BACKGROUND AND OBJECTIVES: To compare mechanical properties of femoral tumor treatments so that better operative strategy for limb tumors surgery is optimized. METHODS: Fourteen femoral CT images were randomly selected to rebuild 3D models by MIMICS. They were then executed by reverse engineering softwares for simulative modes. Mode #1: Intralesional curettage with cement filled plus fixator; Mode #2: Distal femur resection with tumorous prosthesis replaced. Finally, the mechanical aspects such as stress and displacement were compared by finite element analysis. RESULTS: Analyzed by AnSys, the observation indexes were measured as follows: for displacement of femurs, d=1.4762 (< a=3.9042 < c=3.9845 < b=4.1159) in mm is the most staple of all models; for displacement of implants (fixators or prostheses), it's similar to the behavior of femurs and with no significant difference; for stresses of femurs, no significant difference was found among all models; the stresses of implants (fixations and prostheses) were observed as d=39.6334 (< a=58.6206 < c=61.8150 < b=62.6626) in MPa correspondently, which is the least; for stresses of the general system, the average of peak values for integrated devices of all models are: d=40.8072 (< a=58.6206 < c=61.7831< b=62.6626) in MPa, which is also the least. As a final result, both maximum values for displacement and stress of mode 2 are lower than those of mode 1. CONCLUSIONS: Our finite element analysis of limb salvage simulation in biomechanics proved that, to treat distal femoral bone tumors, prosthetic replacement is more efficient than intralesional curettage.


Assuntos
Neoplasias Ósseas , Salvamento de Membro , Fenômenos Biomecânicos , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/cirurgia , Curetagem , Análise de Elementos Finitos , Humanos , Estresse Mecânico
8.
Comput Methods Programs Biomed ; 193: 105491, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32388067

RESUMO

BACKGROUND AND OBJECTIVES: There are many fixation methods for Pauwels- III fracture, the most common implants are Locking Plate (LP), Dynamic Hip Screw (DHS), Multiple Lag Screw (MLS), and mixed fixture (DHS+MLS) implants, the common procedure is HemiArthroplasty (HA). However, how these fixtures biomechanically function is not clear. The aims of this study are to compare the mechanical behaviors of these five implants by finite element modeling and determinate the most suitable procedure for individuals with Pauwels- III fractures. METHODS: We gathered 20 sets of femur images from CT scans in the *.dicom format first, and then processed them by using reverse engineering software programs, such as Mimics, Geomagic Studio, UG-8, Pro-Engineer and HyperMesh. Finally, we assembled and analyzed the five types of fixture models, the LP, DHS, MLS, DHS+LS and HA models, by AnSys. RESULTS: These numerical models of Pauwels III fractures, including fixators and a simulative HA, were validated by a previous study and a cadaver test. Our analytical findings include the following: the displacements of all fixtures were between 0.3801 and 1.0834 mm, and the differences were not statistically significantly different; the resulting average peaks in stress were e(Ha) = 43.859 ≤ d(LP) = 60.435 ≤ b(MLS) = 68.678 < c(LS+DHS) = 98.478 < a(DHS) = 248.595 in Mpa, indicating that the stress of DHS and DHS+LS are greater than those of LP, HA and MLS, while the last 3 models were not significantly different. CONCLUSIONS: To optimize the treatment for Pauwels III factures clinically, HA and LP should be proposed.


Assuntos
Fraturas do Colo Femoral , Fenômenos Biomecânicos , Parafusos Ósseos , Fêmur , Análise de Elementos Finitos , Fixação Interna de Fraturas , Humanos
9.
Bone ; 136: 115351, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32276154

RESUMO

BACKGROUND: Standard of care metabolic bone disease assessment relies on changes to bone quantity, which can only be detected after structural changes occur. PURPOSE: To investigate the usefulness of Bone Metabolism Score (BMS), derived from fluorine 18 labeled sodium fluoride (18F-NaF) PET/CT imaging as a biomarker of localized metabolic changes at the femoral neck. METHODS: In this retrospective study, 139 participants (68 females and 71 males, ages 21-75 years) that had undergone 18F-NaF PET/CT were included. BMS was calculated as the ratio of standard uptake value (SUV) in the bone region to that of the total region. Correlations and linear regressions of BMS with age, CT-derived bone mineral density (BMD), body mass index (BMI), height, and weight were conducted. Differences in BMS between women younger and older than the age of 50 years were assessed. Inter- and intra-operator reproducibility was evaluated by coefficient of variation (CV) and intra-class correlation coefficient (ICC). RESULTS: Among females, age was negatively correlated with left and right whole BMS (5.61% and 4.90% drop in BMS per decade of life) and left and right cortical BMS (10.50% and 10.09% drop in BMS per decade of life). BMS of women older than 50 years was lower than BMS of women younger than 50 years (P < .0001). Among males, age was negatively correlated with left and right whole BMS (4.29% and 4.25% drop in BMS per decade of life) and left and right cortical BMS (9.13% and 10.30% drop in BMS per decade of life). BMD was positively correlated with whole (r = 0.80, P < .0001) and cortical (r = 0.92, P < .0001) BMS. CONCLUSIONS: BMS could provide functional insight regarding bone metabolism in the femoral neck to complement bone health status assessed through conventional structural imaging. The methodology described herein could be potentially useful for assessing hip fracture risk in individuals when BMD tests provide borderline determination of bone disease.


Assuntos
Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Fluoreto de Sódio , Adulto , Idoso , Densidade Óssea , Feminino , Colo do Fêmur/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Adulto Jovem
10.
J Invest Surg ; 33(5): 428-437, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30516078

RESUMO

Background: Little is known about how biomechanics govern the five fixtures such as DHS, MLS, DHS + LS, LP, and HA are accepted as common therapeutic techniques. Aims and objectives: A series of numerical models for a femoral neck fracture of Pauwels-I will be constructed by innovative approach of finite element in order to determine the most optimized option in comparison with biomechanical performance. Method: Twenty sets of computer tomography scanned femora were imported onto Mimics to extract 3 D models; these specimens were transferred to Geomagic-Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; 5 sorts of fixture were then expressed by Pro-Engineer virtually. After processing with HyperMesh, all compartments (fracture model + internal implant) were assembled onto 5 systems: "Dynamic Hip Screw (DHS), Multiple Lag screw (MLS), DHS + LS, femoral Locking Plate (LP) and HemiArthroplasty (HA)." Eventually, numerical models of the finite-elemental analysis were exported to AnSys to determine the solution. Result: Four models of fixation and a simulation of HA for Pauwels-I were established, validated, and analyzed with the following findings: In term of displacement, these 5 fixtures ranged between 0.3801 and 0.7536 mm have no significant difference; in term of stress, the averages of peaks for integral assemblage are b(MLS) = 43.5766 ≈< d(LP) = 43.6657 ≈< e(Ha) = 43.6657 < c(DHS + LS) = 66.5494 < a(DHS) = 105.617 in MPa indicate that MLS, LP and HA are not significantly different, but less than DHS + LS or DHS in each. Conclusion: A fixture of MLS or LP with optional HA should be recommended to clinically optimize a Pauwels-I facture.


Assuntos
Fraturas do Colo Femoral/cirurgia , Fixação Interna de Fraturas/métodos , Hemiartroplastia/métodos , Modelos Biológicos , Osteotomia/métodos , Adulto , Fenômenos Biomecânicos , Placas Ósseas , Parafusos Ósseos , Módulo de Elasticidade , Fraturas do Colo Femoral/classificação , Fraturas do Colo Femoral/diagnóstico , Fêmur/diagnóstico por imagem , Fêmur/lesões , Fêmur/cirurgia , Análise de Elementos Finitos , Fixação Interna de Fraturas/instrumentação , Hemiartroplastia/instrumentação , Prótese de Quadril , Humanos , Imageamento Tridimensional , Teste de Materiais , Osteotomia/instrumentação , Desenho de Prótese , Tomografia Computadorizada por Raios X
11.
Eur J Nucl Med Mol Imaging ; 47(7): 1678-1687, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31734781

RESUMO

AIMS: To investigate the benefit of utilizing 18F-sodium fluoride (NaF) PET/CT over calcium and Framingham scoring for potential preventative coronary artery disease (CAD) intervention. METHODS AND RESULTS: This retrospective study included 136 participants (ages 21-75, BMI 18-43 kg/m2): 86 healthy controls and 50 patients. CT heart segmentations were superimposed onto PET images and standard uptake values (SUV) were calculated by a semi-auto segmentation method of drawing volumes of interest around the heart. Intergroup comparisons were made matching 37 patient/control pairs based on age, gender, and BMI. ROC curves were generated to determine how well SUV and Framingham methods predicted patient status. Regressions including all 136 participants were performed between SUV, age, and BMI. Patients exhibited higher average SUV (SUVmean; P = 0.006) and Framingham scores (P = 0.02) than controls. However, ROC curves indicated that SUVmean could discriminate patients from controls (AUC = 0.63, P = 0.049), but Framingham scores could not (AUC = 0.44, P = 0.38). Calcium scores and maximum SUV (SUVmax) did not differ between patients and controls. SUVmean correlated with age and BMI among females (age, partial R2 = 0.16, P = 0.001; BMI, partial R2 = 0.12, P = 0.004) and males (age, partial R2 = 0.28, P < 0.0001; BMI, partial R2 = 0.22, P < 0.0001). CONCLUSION: Unlike calcium scores, NaF PET/CT-derived values differed between patients and controls. Framingham risk score patterns echoed those of SUVmean, but were not sensitive enough to predict patient status. SUVmean values increased with age and BMI. Therefore, incorporation of NaF PET/CT into routine prognostic CAD assessment might prove beneficial for assessing early stage plaque calcification in coronary arteries. TRIAL REGISTRATION: ClinicalTrials.gov (NCT01724749).


Assuntos
Vasos Coronários , Radioisótopos de Flúor , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Calcificação Vascular , Adulto , Idoso , Cálcio , Vasos Coronários/diagnóstico por imagem , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fluoreto de Sódio , Calcificação Vascular/diagnóstico por imagem , Adulto Jovem
12.
BMC Musculoskelet Disord ; 18(1): 295, 2017 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-28693543

RESUMO

BACKGROUND: There is no universal hip implant suitably fills all femoral types, whether prostheses of porous short-stem suitable for Hip Arthroplasty is to be measured scientifically. METHODS: Ten specimens of femurs scanned by CT were input onto Mimics to rebuild 3D models; their *stl format dataset were imported into Geomagic-Studio for simulative osteotomy; the generated *.igs dataset were interacted by UG to fit solid models; the prosthesis were obtained by the same way from patients, and bored by punching bears designed by Pro-E virtually; cements between femora and prosthesis were extracted by deleting prosthesis; in HyperMesh, all compartments were assembled onto four artificial joint style as: (a) cemented long-stem prosthesis; (b) porous long-stem prosthesis; (c) cemented short-stem prosthesis; (d) porous short-stem prosthesis. Then, these numerical models of Finite Element Analysis were exported to AnSys for numerical solution. RESULTS: Observed whatever from femur or prosthesis or combinational femora-prostheses, "Kruskal-Wallis" value p > 0.05 demonstrates that displacement of (d) ≈ (a) ≈ (b) ≈ (c) shows nothing different significantly by comparison with 600 N load. If stresses are tested upon prosthesis, (d) ≈ (a) ≈ (b) ≈ (c) is also displayed; if upon femora, (d) ≈ (a) ≈ (b) < (c) is suggested; if upon integral joint, (d) ≈ (a) < (b) < (c) is presented. CONCLUSIONS: Mechanically, these four sorts of artificial joint replacement are stabilized in quantity. Cemented short-stem prostheses present the biggest stress, while porous short-stem & cemented long-stem designs are equivalently better than porous long-stem prostheses and alternatives for femoral-head replacement. The preferred design of those two depends on clinical conditions. The cemented long-stem is favorable for inactive elders with osteoporosis, and porously punched cementless short-stem design is suitable for patients with osteoporosis, while the porously punched cementless short-stem is favorable for those with a cement allergy. Clinically, the strength of this study is to enable preoperative strategy to provide acute correction and decrease procedure time.


Assuntos
Artroplastia de Quadril/instrumentação , Análise de Elementos Finitos , Prótese de Quadril , Imageamento Tridimensional/métodos , Desenho de Prótese/métodos , Realidade Virtual , Adulto , Artroplastia de Quadril/métodos , Feminino , Fêmur/diagnóstico por imagem , Fêmur/cirurgia , Prótese de Quadril/normas , Humanos , Porosidade , Desenho de Prótese/normas , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
13.
Cleft Palate Craniofac J ; 53(1): 22-9, 2016 01.
Artigo em Inglês | MEDLINE | ID: mdl-25531739

RESUMO

OBJECTIVE: To evaluate the reproducibility of three nonverbal facial expressions using a three-dimensional motion capture system. DESIGN: Prospective, cross-sectional, controlled study. SETTING: Glasgow Dental Hospital and School, University of Glasgow, United Kingdom. PATIENTS AND PARTICIPANTS: Thirty-two subjects, 16 males and 16 females. METHODS: With a three-dimensional video passive stereophotogrammetry imaging system, maximal smile, cheek puff, and lip purse were captured for each subject. Anatomical facial landmarks were digitized on the first frame and then tracked automatically. The same facial expressions were captured 15 minutes later. MAIN OUTCOME MEASURES: The magnitude of each expression and speed of landmark displacement were calculated. The landmark motion curves were spatially and temporally aligned to calculate the similarity of the dynamic movements of the same landmarks between the captures. RESULTS: There were no significant differences between individuals for magnitude (P = .892) or for speed (P = .456). There were significant differences in landmark movement similarity (P = .011); similarity was more reproducible for maximal smile. There was no significant gender effect on the difference in magnitude. There was a significant gender effect on speed to reach maximal smile (P = .044) and a pursed-lip expression (P = .038). There was a significant gender effect on landmark movement similarities (P = .031) for cheek puff expression. CONCLUSIONS: There were no differences in magnitude and speed for maximal smile, cheek puff, and lip purse between the two captures for all participants. For individual expressions, maximal smile expression had the highest similarity value for individual landmarks.


Assuntos
Expressão Facial , Imageamento Tridimensional/métodos , Fotogrametria/métodos , Adolescente , Adulto , Pontos de Referência Anatômicos , Estudos Transversais , Feminino , Humanos , Masculino , Estudos Prospectivos , Reprodutibilidade dos Testes , Escócia
14.
Med Biol Eng Comput ; 54(2-3): 475-84, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26133282

RESUMO

A multi-view three-dimensional stereophotogrammetry system was developed to capture 3D shape of breasts for breast cancer patients. The patients had received immediate unilateral breast reconstruction after mastectomy by the extended latissimus dorsi flap and without contralateral surgery. In order to capture the whole breast shape including the inframammary fold, the patients were introduced to the imaging room and leaned over the imaging rig to open up the inframammary fold and to expose the entire area of each breast. The imaging system consisted of eight high-resolution ([Formula: see text] pixels) digital cameras and four flash units. The cameras were arranged in four stereo pairs from four different view angles to cover the whole surface of the breasts. The system calibration was carried out ahead of every capture session, and the stereo images were matched to generate four range images to be integrated using an elastic model proposed. A watertight breast mesh model was reconstructed to measure the volume of the breast captured. The accuracy of using the developed multi-view stereophotogrammetry system for breast volume measurement was 11.12cc with SEM 7.74cc, comparing to the measurements of the water displacement method. It was concluded that the 3D stereophotogrammetry image system developed was more reliable than the method of water displacement.


Assuntos
Mamoplastia/métodos , Mastectomia/métodos , Fotogrametria/métodos , Artefatos , Calibragem , Feminino , Humanos , Imageamento Tridimensional
15.
Eur J Radiol ; 82(11): e707-14, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23954015

RESUMO

OBJECTIVE: To explore the feasibility of longitudinally measuring acute traction injury to the sciatic nerve using 1.5 T clinical MRI scanner of diffusion tensor imaging (DTI) and to analyze the associations of the measurements [regarding fractional anisotropy (FA), apparent diffusion coefficient (ADC), eigenvalue (λ|| and λ⊥)] with limb function and pathology. MATERIALS AND METHODS: Acute traction injuries to the sciatic nerve were created in the right hind limbs of 32 New Zealand white rabbits, the left hind limbs were chosen as sham operation nerves. MRI scans were performed at intervals from pre-operation through 8 weeks post-operation follow up. Scanning sequences included T2WI, STIR, and single shot spin echo DTI with single shot EPI acquisition (SE-DTI-SSEPI). Parameters of FA, ADC, axial diffusivity (λ||) and radial diffusivity (λ⊥) were then calculated from the DTI. The limb functions and pathologic changes were evaluated and compared. RESULTS: Diffusion Tensor Tractography (DTT) only revealed the proximal portion of the injured nerves 1-3 days after traction injury but did not reveal the nerve of the distal and traction portions at all. Nerve fibers of the distal and traction portions were not revealed by DTT until after the 1st week. They were elongated gradually and recovered almost to the normal at 8th week. The value of FA and λ⊥of the injured nerves, which varied in different portions, were significantly different between the traction injury nerves and the sham operation nerves, whereas the value of ADC and λ|| were not significantly different. The curve lines of FA value-time for the proximal, traction and distal portions of the injured nerve correlated well to the functional and pathological changes of the limb affected, while the DTI parameters did not change that much in the sham-operated nerves. CONCLUSIONS: DTI obtained on a 1.5 T clinical MRI scanner can demonstrate early abnormal changes following traction injury to the sciatic nerve in rabbits. The curve lines of FA-time and λ⊥-time for nerve traction injury are consistent with the pathological and functional changes of the limb affected. DTI may thus be a sensitive and reliable method to evaluate degeneration and regeneration of the nerve after traction injury.


Assuntos
Imagem de Tensor de Difusão/métodos , Traumatismos dos Nervos Periféricos/diagnóstico , Traumatismos dos Nervos Periféricos/fisiopatologia , Neuropatia Ciática/diagnóstico , Neuropatia Ciática/fisiopatologia , Tração , Doença Aguda , Animais , Feminino , Humanos , Estudos Longitudinais , Masculino , Coelhos , Recuperação de Função Fisiológica , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
Eur J Radiol ; 81(3): e406-13, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22260897

RESUMO

OBJECTIVE: To investigate a registration approach for 2-dimension (2D) based on characteristic localization to achieve 3-dimension (3D) fusion from images of PET, CT and MR one by one. METHOD: A cubic oriented scheme of"9-point & 3-plane" for co-registration design was verified to be geometrically practical. After acquisiting DICOM data of PET/CT/MR (directed by radiotracer 18F-FDG etc.), through 3D reconstruction and virtual dissection, human internal feature points were sorted to combine with preselected external feature points for matching process. By following the procedure of feature extraction and image mapping, "picking points to form planes" and "picking planes for segmentation" were executed. Eventually, image fusion was implemented at real-time workstation mimics based on auto-fuse techniques so called "information exchange" and "signal overlay". RESULT: The 2D and 3D images fused across modalities of [CT+MR], [PET+MR], [PET+CT] and [PET+CT+MR] were tested on data of patients suffered from tumors. Complementary 2D/3D images simultaneously presenting metabolic activities and anatomic structures were created with detectable-rate of 70%, 56%, 54% (or 98%) and 44% with no significant difference for each in statistics. CONCLUSION: Currently, based on the condition that there is no complete hybrid detector integrated of triple-module [PET+CT+MR] internationally, this sort of multiple modality fusion is doubtlessly an essential complement for the existing function of single modality imaging.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Imagem Multimodal , Neoplasias/diagnóstico , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade
17.
Biomed Tech (Berl) ; 57(5): 413-22, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25854668

RESUMO

BACKGROUND AND AIMS: Because there is no complete three-dimensional (3D) hybrid detector integrated PET+MRI internationally, this study aims to investigate a registration approach for a two-dimensional (2D) hybrid based on characteristic localization to achieve a 3D fusion from the images of PET and MRI as a whole. METHODS: A cubic-oriented scheme of "9-point and 3-plane" for a coregistration design was verified to be geometrically practical. Through 3D reconstruction and virtual dissection, human internal feature points were sorted to combine with preselected external feature points for matching process. By following the procedure of feature extraction and image mapping, the processes of "picking points to form planes" and "picking planes for segmentation" were executed. Eventually, the image fusion was implemented at the real-time workstation Mimics based on auto-fuse techniques called "information exchange" and "signal overlay". RESULTS: A complementary 3D image across PET+MRI modalities, which simultaneously present metabolic activities and anatomic structures, was created with a detectable rate of 56%. This is equivalent to the detectable rate of PET+CT or MRI+CT with no statistically significant difference, and it facilitates a 3D vision that is not yet functional for 2D hybrid imaging. CONCLUSIONS: This cross-modality fusion is doubtless an essential complement for the existing toolkit of a 2D hybrid device. Thus, it would potentially improve the efficiency of diagnosis and therapy for oncology.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Imageamento por Ressonância Magnética/métodos , Neoplasias/diagnóstico , Tomografia por Emissão de Pósitrons , Humanos , Imageamento Tridimensional/métodos , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X/métodos
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