Publications by authors named "Michael Y Chen"

57 Publications

Challenges targeting cancer neoantigens in 2021: a systematic literature review.

Expert Rev Vaccines 2021 Jun 9:1-11. Epub 2021 Jun 9.

Department of Surgery, Washington University and Siteman Cancer Center in St. Louis, St Louis, Missouri, USA.

: Cancer neoantigens represent important targets of cancer immunotherapy. The goal of cancer neoantigen vaccines is to induce neoantigen-specific immune responses and antitumor immunity while minimizing the potential for autoimmune toxicity. Advances in sequencing technologies, neoantigen prediction algorithms, and other technologies have dramatically improved the ability to identify and prioritize cancer neoantigens. Unfortunately, results from preclinical studies and early phase clinical trials highlight important challenges to the successful clinical translation of neoantigen cancer vaccines.: In this review, we provide an overview of current strategies for the identification and prioritization of cancer neoantigens with a particular emphasis on the two most common strategies used for neoantigen identification: (1) direct identification of peptide ligands eluted from peptide-MHC complexes, and (2) next-generation sequencing combined with neoantigen prediction algorithms. We highlight the limitations of current neoantigen prediction pipelines, and discuss broader challenges associated with cancer neoantigen vaccines including tumor purity/heterogeneity and the immunosuppressive tumor microenvironment.: Despite current limitations, neoantigen prediction is likely to improve rapidly based on advances in sequencing, machine learning, and information sharing. The successful development of robust cancer neoantigen prediction strategies is likely to have a significant impact, with the potential to facilitate cancer neoantigen vaccine design.
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http://dx.doi.org/10.1080/14760584.2021.1935248DOI Listing
June 2021

Staging of the Axilla in Breast Cancer and the Evolving Role of Axillary Ultrasound.

Breast Cancer (Dove Med Press) 2021 17;13:311-323. Epub 2021 May 17.

Department of Surgery, Washington University, St Louis, MS, USA.

Axillary lymph nodes have long been recognized as a route for breast cancer to spread systemically. As a result, staging of the axilla has always played a central role in the treatment of breast cancer. Anatomic staging was believed to be important for two reasons: 1) it predicts prognosis and guides medical therapy, and 2) it is a potential therapy for removal of disease in the axilla. This paradigm has now been called into question. Prognostic information is driven increasingly by tumor biology, and trials such as the ACOSOG Z0011 demonstrates removal of axillary disease is not therapeutic. Staging of the axilla has undergone a dramatic de-escalation; however, sentinel lymph node biopsy (SLNB) is still an invasive surgery and represents a large economic burden on the healthcare system. In this review, we outline the changing paradigms of axillary staging in breast cancer from emphasis on anatomic staging to tumor biology, and the evolving role of axillary ultrasound, bringing patients less invasive and more personalized therapy.
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http://dx.doi.org/10.2147/BCTT.S273039DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8139849PMC
May 2021

3D Printing Improved Testicular Prostheses: Using Lattice Infill Structure to Modify Mechanical Properties.

Front Surg 2021 20;8:626143. Epub 2021 Apr 20.

Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia.

Patients often opt for implantation of testicular prostheses following orchidectomy for cancer or torsion. Recipients of testicular prostheses report issues regarding firmness, shape, size, and position, aspects of which relate to current limitations of silicone materials used and manufacturing methods for soft prostheses. We aim to create a 3D printable testicular prosthesis which mimics the natural shape and stiffness of a human testicle using a lattice infill structure. Porous testicular prostheses were engineered with relative densities from 0.1 to 0.9 using a repeating cubic unit cell lattice inside an anatomically accurate testicle 3D model. These models were printed using a multi-jetting process with an elastomeric material and compared with current market prostheses using shore hardness tests. Additionally, standard sized porous specimens were printed for compression testing to verify and match the stiffness to human testicle elastic modulus (E-modulus) values from literature. The resulting 3D printed testicular prosthesis of relative density between 0.3 and 0.4 successfully achieved a reduction of its bulk compressive E-modulus from 360 KPa to a human testicle at 28 Kpa. Additionally, this is the first study to quantitatively show that current commercial testicular prostheses are too firm compared to native tissue. 3D printing allows us to create metamaterials that match the properties of human tissue to create customisable patient specific prostheses. This method expands the use cases for existing biomaterials by tuning their properties and could be applied to other implants mimicking native tissues.
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http://dx.doi.org/10.3389/fsurg.2021.626143DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8093764PMC
April 2021

Rapid Segmentation of Renal Tumours to Calculate Volume Using 3D Interpolation.

J Digit Imaging 2021 Feb 9. Epub 2021 Feb 9.

Department of Urology, Redcliffe Hospital, Redcliffe, QLD, Australia.

Small renal masses are commonly diagnosed with modern medical imaging. Renal tumour volume has been explored as a prognostic tool to help decide when intervention is needed and appears to provide additional prognostic information for smaller tumours compared with tumour diameter. However, the current method of calculating tumour volume in clinical practice uses the ellipsoid equation (π/6 × length × width × height) which is an oversimplified approach. Some research groups trace the contour of the tumour in every image slice which is impractical for clinical use. In this study, we demonstrate a method of using 3D segmentation software and the 3D interpolation method to rapidly calculate renal tumour volume in under a minute. Using this method in 27 patients that underwent radical or partial nephrectomy, we found a 10.07% mean absolute difference compared with the traditional ellipsoid method. Our segmentation volume was closer to the calculated histopathological tumour volume than the traditional method (p = 0.03) with higher Lin's concordance correlation coefficient (0.79 vs 0.72). 3D segmentation has many uses related to 3D printing and modelling and is becoming increasingly common. Calculation of tumour volume is one additional benefit it provides. Further studies on the association between segmented tumour volume and prognosis are needed.
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http://dx.doi.org/10.1007/s10278-020-00416-zDOI Listing
February 2021

COVID-19 in pregnancy: a systematic review of chest CT findings and associated clinical features in 427 patients.

Clin Imaging 2021 Jul 13;75:75-82. Epub 2021 Jan 13.

Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, United States of America; Department of Radiology, Los Angeles, CA 90033, United States of America. Electronic address:

Purpose: Our purpose was to conduct a comprehensive systematic review of all existing literature regarding imaging findings on chest CT and associated clinical features in pregnant patients diagnosed with COVID-19.

Materials & Methods: A literature search was conducted on April 21, 2020 and updated on July 24, 2020 using PubMed, Embase, World Health Organization, and Google Scholar databases. Only studies which described chest CT findings of COVID-19 in pregnant patients were included for analysis.

Results: A total of 67 articles and 427 pregnant patients diagnosed with COVID-19 were analyzed. The most frequently encountered pulmonary findings on chest CT were ground-glass opacities (77.2%, 250/324), posterior lung involvement (72.5%, 50/69), multilobar involvement (71.8%, 239/333), bilateral lung involvement (69.4%, 231/333), peripheral distribution (68.1%, 98/144), and consolidation (40.9%, 94/230). Pregnant patients were also found to present more frequently with consolidation (40.9% vs. 21.0-31.8%) and pleural effusion (30.0% vs. 5.0%) in comparison to the general population. Associated clinical features included antepartum fever (198 cases), lymphopenia (128 cases), and neutrophilia (97 cases). Of the 251 neonates delivered, 96.8% had negative RT-PCR and/or IgG antibody testing for COVID-19. In the eight cases (3.2%) of reported neonatal infection, tests were either conducted on samples collected up to 72 h after birth or were found negative on all subsequent RT-PCR tests.

Conclusion: Pregnant patients appear to present more commonly with more advanced COVID-19 CT findings compared to the general adult population. Furthermore, characteristic laboratory abnormalities found in pregnant patients tended to mirror those found in the general patient population. Lastly, results from neonatal testing suggest a low risk of vertical transmission.
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http://dx.doi.org/10.1016/j.clinimag.2021.01.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7804384PMC
July 2021

Variability in accuracy of prostate cancer segmentation among radiologists, urologists, and scientists.

Cancer Med 2020 10 18;9(19):7172-7182. Epub 2020 Aug 18.

Science and Engineering Faculty, Queensland University of Technology, Brisbane, Queensland, Australia.

Background: There is increasing research in using segmentation of prostate cancer to create a digital 3D model from magnetic resonance imaging (MRI) scans for purposes of education or surgical planning. However, the variation in segmentation of prostate cancer among users and potential inaccuracy has not been studied.

Methods: Four consultant radiologists, four consultant urologists, four urology trainees, and four nonclinician segmentation scientists were asked to segment a single slice of a lateral T3 prostate tumor on MRI ("Prostate 1"), an anterior zone prostate tumor MRI ("Prostate 2"), and a kidney tumor computed tomography (CT) scan ("Kidney"). Time taken and self-rated subjective accuracy out of a maximum score of 10 were recorded. Root mean square error, Dice coefficient, Matthews correlation coefficient, Jaccard index, specificity, and sensitivity were calculated using the radiologists as the ground truth.

Results: There was high variance among the radiologists in segmentation of Prostate 1 and 2 tumors with mean Dice coefficients of 0.81 and 0.58, respectively, compared to 0.96 for the kidney tumor. Urologists and urology trainees had similar accuracy, while nonclinicians had the lowest accuracy scores for Prostate 1 and 2 tumors (0.60 and 0.47) but similar for kidney tumor (0.95). Mean sensitivity in Prostate 1 (0.63) and Prostate 2 (0.61) was lower than specificity (0.92 and 0.93) suggesting under-segmentation of tumors in the non-radiologist groups. Participants spent less time on the kidney tumor segmentation and self-rated accuracy was higher than both prostate tumors.

Conclusion: Segmentation of prostate cancers is more difficult than other anatomy such as kidney tumors. Less experienced participants appear to under-segment models and underestimate the size of prostate tumors. Segmentation of prostate cancer is highly variable even among radiologists, and 3D modeling for clinical use must be performed with caution. Further work to develop a methodology to maximize segmentation accuracy is needed.
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http://dx.doi.org/10.1002/cam4.3386DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7541146PMC
October 2020

Three-dimensional printing versus conventional machining in the creation of a meatal urethral dilator: development and mechanical testing.

Biomed Eng Online 2020 Jul 1;19(1):55. Epub 2020 Jul 1.

Science and Engineering Faculty, Queensland University of Technology, Brisbane, Australia.

Background: Three-dimensional (3D) printing is a promising technology, but the limitations are often poorly understood. We compare different 3D printing methods with conventional machining techniques in manufacturing meatal urethral dilators which were recently removed from the Australian market.

Methods: A prototype dilator was 3D printed vertically orientated on a low-cost fused deposition modelling (FDM) 3D printer in polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). It was also 3D printed horizontally orientated in ABS on a high-end FDM 3D printer with soluble support material, as well as on an SLS 3D printer in medical nylon. The dilator was also machined in stainless steel using a lathe. All dilators were tested mechanically in a custom rig by hanging calibrated weights from the handle until the dilator snapped.

Results: The horizontally printed ABS dilator experienced failure at a greater load than the vertically printed PLA and ABS dilators, respectively (503 g vs 283 g vs 163 g, p < 0.001). The SLS nylon dilator and machined steel dilator did not fail. The steel dilator is the most expensive with a quantity of five at 98 USD each, but this decreases to 30 USD each for a quantity of 1000. In contrast, the cost for the SLS dilator is 33 USD each for five and 27 USD each for 1000.

Conclusions: Low-cost FDM 3D printing is not a replacement for conventional manufacturing. 3D printing is best used for patient-specific parts, prototyping or manufacturing complex parts that have additional functionality that cannot otherwise be achieved.
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http://dx.doi.org/10.1186/s12938-020-00799-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7329536PMC
July 2020

Solitary rib lesions showing prostate-specific membrane antigen (PSMA) uptake in pre-treatment staging Ga-PSMA-11 positron emission tomography scans for men with prostate cancer: benign or malignant?

BJU Int 2020 09 28;126(3):396-401. Epub 2020 Jul 28.

Wesley Hospital, Brisbane, Qld, Australia.

Objectives: To determine the proportion of solitary rib lesions on pre-treatment Gallium-labelled prostate-specific membrane antigen (PSMA)/computed tomography (CT) scans in men with prostate cancer that are malignant and examine any predictive factors.

Patients And Methods: This retrospective single tertiary referral institution cohort study of men reviewed the results of Ga-PSMA-11 positron emission tomography (PET)/CT scans performed for primary staging prior to treatment of prostate cancer from July 2014 to September 2019. Men with PSMA uptake outside the prostate in only the rib lesion were included. A solitary rib lesion was considered to be malignant if it increased in size on follow-up imaging. A lesion was considered benign if the prostate-specific antigen (PSA) level remained <0.1 µg/L following a radical prostatectomy (RP), <2 µg/L above nadir following radiotherapy (RT) as per the Phoenix criteria, histology was benign on rib biopsy, or follow-up imaging showed no growth of the rib lesion. If a lesion did not meet these criteria it was considered indeterminate.

Results: A total of 62 men had PSMA uptake in a solitary rib lesion; 54 went on to have RPs and eight underwent RT. In all, 61 of the men (98.4%) met the criteria for a benign rib lesion. Only one man had a false-negative malignant lesion. This man had a rib lesion with a low maximum standardised uptake value (SUV ) of 2.21 reported as benign, but the postoperative PSA level was 0.67 µg/L and the rib lesion progressed on follow-up imaging, with development of widespread metastases. Of the benign rib lesions, there were four false positives reported as possible metastases. Three had percutaneous rib biopsies, two of which came back with benign histology and one was indeterminate. The indeterminate biopsy patient had a RP and his postoperative PSA level was <0.1 µg/L. A total of 43 (69.4%) men with benign rib lesions had a SUV greater than the SUV of the malignant lesion.

Conclusion: To our knowledge, this is the first cohort study of men with PSMA-avid solitary rib lesions on pre-treatment Ga-PSMA PET/CT staging scans for prostate cancer. Our results indicate that the vast majority of these lesions have low-intensity uptake and are benign. Intervention to confirm this is not usually required.
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http://dx.doi.org/10.1111/bju.15152DOI Listing
September 2020

Multi-colour extrusion fused deposition modelling: a low-cost 3D printing method for anatomical prostate cancer models.

Sci Rep 2020 06 19;10(1):10004. Epub 2020 Jun 19.

Redcliffe Hospital, Metro North Hospital Health Service, Queensland, Australia.

Three-dimensional (3D) printed prostate cancer models are an emerging adjunct for urological surgical planning and patient education, however published methods are costly which limits their translation into clinical practice. Multi-colour extrusion fused deposition modelling (FDM) can be used to create 3D prostate cancer models of a quality comparable to more expensive techniques at a fraction of the cost. Three different 3D printing methods were used to create the same 3D prostate model: FDM, colour jet printing (CJP) and material jetting (MJ), with a calculated cost per model of USD 20, USD 200 and USD 250 respectively. When taking into account the cost, the FDM prostate models are the most preferred 3D printing method by surgeons. This method could be used to manufacture low-cost 3D printed models across other medical disciplines.
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http://dx.doi.org/10.1038/s41598-020-67082-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7305153PMC
June 2020

Current applications of three-dimensional printing in urology.

BJU Int 2020 01 6;125(1):17-27. Epub 2019 Nov 6.

Redcliffe Hospital, Metro North Hospital and Health Service, Brisbane, Queensland, Australia.

Three-dimensional (3D) printing or additive manufacturing is a new technology that has seen rapid development in recent years with decreasing costs. 3D printing allows the creation of customised, finely detailed constructs. Technological improvements, increased printer availability, decreasing costs, improved cell culture techniques, and biomaterials have enabled complex, novel and individualised medical treatments to be developed. Although the long-term goal of printing biocompatible organs has not yet been achieved, major advances have been made utilising 3D printing in biomedical engineering. In this literature review, we discuss the role of 3D printing in relation to urological surgery. We highlight the common printing methods employed and show examples of clinical urological uses. Currently, 3D printing can be used in urology for education of trainees and patients, surgical planning, creation of urological equipment, and bioprinting. In this review, we summarise the current applications of 3D-printing technology in these areas of urology.
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http://dx.doi.org/10.1111/bju.14928DOI Listing
January 2020

Frailty, Implantable Cardioverter Defibrillators, and Mortality: a Systematic Review.

J Gen Intern Med 2019 10 1;34(10):2224-2231. Epub 2019 Jul 1.

New England Geriatric Research, Education, and Clinical Center (GRECC), VA Boston Healthcare System, 150 South Huntington St, Boston, MA, 02130, USA.

Background: Evidence for the benefit of implantable cardioverter defibrillators (ICD) in preventing sudden cardiac death (SCD) in older adults is mixed; age alone may not predict benefit. Frailty may help identify patients in whom an ICD does not improve overall mortality risk.

Methods: Structured search of PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials on 1/31/2019, without language restriction, with terms for ICD, frailty, and mortality. Frailty was defined broadly using any validated single component (e.g., walking speed, weight loss) or multi-component tool (e.g., cumulative deficit index). Each study was assessed for quality and risk of bias.

Results: We identified and screened 2649 titles, reviewed 280 abstracts, and extracted 71 articles. Nine articles, including two RCTs, one prospective cohort, and six retrospective cohort studies met all criteria. The most common reason for exclusion was a lack of frailty definition. Frailty definitions were heterogeneous, including cumulative deficit models, low weight, and walking speed. Follow-up time for mortality differed: from days to > 6 years. All studies indicated that mortality was higher amongst individuals identified as frail, regardless of definition. In one RCT, slow walkers did not benefit from ICD therapy after 3 years. A cohort of 83,792 Medicare beneficiaries in an ICD registry reported higher 1-year mortality following ICD in those with frailty or dementia. Four studies reported an association between being underweight and increased mortality following ICD placement.

Conclusion: Existing literature suggests that individuals with frailty may not benefit from ICD placement for primary prevention of SCD.
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http://dx.doi.org/10.1007/s11606-019-05100-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6816602PMC
October 2019

Hospice utilization in advanced cervical malignancies: An analysis of the National Inpatient Sample.

Gynecol Oncol 2019 03 23;152(3):594-598. Epub 2018 Dec 23.

Division of Gynecologic Oncology, SUNY Downstate Medical Center, United States of America.

Objective: Hospice services improve quality of life and outcomes for patients and caretakers, compared to inpatient mortality. This study identifies factors that exert the strongest influence on end-of-life care modalities in patients with cervical cancer.

Methods: Admissions with a diagnosis of cervical cancer that were discharged to hospice or died in-hospital were identified in the National Inpatient Sample years 2007-2011, excluding admissions coded for hysterectomy. Logistic regression models were used to examine differences in age, race, length of stay, primary payer, hospital region, admission type, hospital bedsize, hospital teaching status, income quartile, and Elixhauser comorbidity index score between the groups.

Results: 2073 admissions with a diagnosis of cervical cancer resulting in hospice discharge (n = 1290) or inpatient death (n = 783) were identified. Age (P = 0.01), hospital region (P = 0.01), length of hospitalization (P < 0.01), Elixhauser comorbidity index score (P = 0.03), and urban vs. rural location (P = 0.01) had a significant impact on disposition in univariate analysis. Admissions of patients categorized as Asian/Pacific Islander (OR = 2.24, 95% CI 1.11-4.49), hospitalizations lasting 0-3 days (OR = 1.57, 95% CI 1.21-2.03), and admissions in rural areas (OR = 1.62, 95% CI 1.12-2.36) had higher rates of in-hospital death compared to the reference groups. Patients aged 18-45 years (OR = 0.69, 95% CI 0.52-0.90) and those treated in the South (OR 0.59, 95% CI 0.45-0.77) and West (OR = 0.50, 95% CI 0.30-0.81) had lower odds ratios of inpatient mortality.

Conclusion: Modalities of care in terminal cervical cancer vary among sociodemographic and clinical factors. This data underscores the continued push for improved end-of-life care among cervical cancer patients and can guide clinicians in appropriate targeted counseling to increase utilization of hospice resources.
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http://dx.doi.org/10.1016/j.ygyno.2018.12.016DOI Listing
March 2019

Epithelial-Myoepithelial Carcinoma of the Base of Tongue with Possible Lung Metastases.

Case Rep Otolaryngol 2017 20;2017:4973573. Epub 2017 Sep 20.

Royal Brisbane and Women's Hospital, Herston, QLD, Australia.

Background: Epithelial-myoepithelial carcinomas are rare neoplasms usually arising from the salivary glands. There is limited evidence in the literature on their prognosis in the base of the tongue but other cases have resolved without recurrence.

Methods: The patient underwent biopsies demonstrating the diagnosis of epithelial-myoepithelial carcinoma of the base of tongue and a PET scan showed multiple bilateral rounded pulmonary nodules.

Results: The patient declined chemotherapy and radiotherapy to maximise his quality of life and passed away under management from palliative care several months later.

Discussion: This is the only case in the literature of this type of carcinoma in the base of the tongue resulting in metastases and a poor prognosis. The case highlights the importance of checking for metastases in such lesions and their potentially serious outcomes if left untreated.
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http://dx.doi.org/10.1155/2017/4973573DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5632446PMC
September 2017

New quantitative classification of the anatomical relationship between impacted third molars and the inferior alveolar nerve.

BMC Med Imaging 2015 Dec 7;15:59. Epub 2015 Dec 7.

School of Dentistry, College of Medicine, China Medical University, 91 Hsueh-Shih Road, Taichung, 40402, Taiwan.

Background: Before extracting impacted lower third molars, dentists must first identify the spatial relationship between the inferior alveolar nerve (IAN) and an impacted lower third molar to prevent nerve injury from the extraction. Nevertheless, the current method for describing the spatial relationship between the IAN and an impacted lower third molar is deficient. Therefore, the objectives of this study were to: (1) evaluate the relative position between impacted lower third molars and the IAN; and (2) investigate the relative position between impacted lower third molars and the IAN by using a cylindrical coordinate system.

Methods: From the radiology department's database, we selected computed tomography images of 137 lower third molars (from 75 patients) requiring removal and applied a Cartesian coordinate system by using Mimics, a medical imaging software application, to measure the distribution between impacted mandibular third molars and the IAN. In addition, the orientation of the lower third molar to the IAN was also measured, but by using a cylindrical coordinate system with the IAN as the origin.

Results: According to the Cartesian coordinate system, most of the IAN runs through the inferior side of the third molar (78.6 %), followed by the lingual side (11.8 %), and the buccal side (8.9 %); only 0.7 % is positioned between the roots. Unlike the Cartesian coordinate system, the cylindrical coordinate system clearly identified the relative position, r and θ, between the IAN and lower third molar.

Conclusions: Using the cylindrical coordinate system to present the relationship between the IAN and lower third molar as (r, θ) might provide clinical practitioners with a more explicit and objective description of the relative position of both sites. However, comprehensive research and cautious application of this system remain necessary.
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http://dx.doi.org/10.1186/s12880-015-0101-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4672479PMC
December 2015

Biomechanical analysis of a temporomandibular joint condylar prosthesis during various clenching tasks.

J Craniomaxillofac Surg 2015 Sep 2;43(7):1194-201. Epub 2015 May 2.

School of Dentistry, College of Medicine, China Medical University, Taichung 404, Taiwan. Electronic address:

The objective of this study was to evaluate the effect of clenching tasks on the stress and stability of a temporomandibular joint (TMJ) condylar prosthesis, as well as on the stress and strain in the whole mandible and bone surrounding three screws. Three-dimensional finite element models of the mandible and a TMJ condylar prosthesis using three screws were established. Six static clenching tasks were simulated in this study: incisal clench (INC), intercuspal position (ICP), right unilateral molar clench (RMOL), left unilateral molar clench (LMOL), right group function (RGF), and left group function (LGF). Based on the simulation of the six clenching tasks, none of the inserted screws or the TMJ condylar prosthesis were broken. In addition, the stability of the TMJ condylar prosthesis was sufficiently high for bone ongrowth. For the whole mandibular bone, the maximum von Mises stress and von Mises strain observed in the cortical bone and cancellous bone were yielded by the ICP and RMOL, respectively. For the bone surrounding the inserted screws, the maximum von Mises stress and von Mises strain in both the cortical bone and cancellous bone were yielded by the LMOL. Clenching tasks had significant effects on the stress distribution of the TMJ condylar prosthesis, as well as on the stress and strain distribution of the whole mandible and the bone surrounding the inserted screws.
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http://dx.doi.org/10.1016/j.jcms.2015.04.016DOI Listing
September 2015

MicroRNA-20a regulates autophagy related protein-ATG16L1 in hypoxia-induced osteoclast differentiation.

Bone 2015 Apr 5;73:145-53. Epub 2014 Dec 5.

Graduate Institute of Clinical Medical Science, China Medical University, No. 91 Hsueh-Shih Rd., Taichung, Taiwan; Department of Anesthesiology, China Medical University Hospital, No. 2 Yu-Der Rd., Taichung, Taiwan. Electronic address:

Autophagy and autophagy-related proteins (ATGs) play decisive roles in osteoclast differentiation. Emerging lines of evidence show the deregulation of miRNA in autophagic responses. However, the role of hypoxia and involvement of miRNA in osteoclast differentiation are unclear. In the present study, we demonstrate that hypoxia caused induction of autophagy and osteoclast differentiation markers in RAW264.7 cells stimulated with M-CSF and RANKL. In addition, miR-20a was significantly repressed during hypoxia and identified as the prime candidate involved in hypoxia-induced osteoclast differentiation. The results from dual luciferase reporter assay revealed that miR-20a directly targets Atg16l1 by binding to its 3'UTR end. Further, miR-20a transfection studies showed significant down regulation of autophagic proteins (LC3-II and ATG16L1) and osteoclast differentiation markers (Nfatc1, Traf6, and Trap) thus confirming the functional role of miR-20a under hypoxic conditions. Results of chromatin immunoprecipitation assay showed that HIF-1α binds to miRNA-20a. From miRNA Q-PCR results, we confirmed that shRNA HIF-1α knockdown significantly downregulated both autophagy (LC3, p62, Atg5, Atg12, Atg16l1, Atg7, Becn1, Atg9a) and osteoclast markers (Traf6, Nfatc1, Ctsk, cFos, Mmp9, Trap) in RAW264.7 cells. Thus, our findings suggest that the regulatory axis of HIF-1α-miRNA-20a-Atg16l1 might be a critical mechanism for hypoxia-induced osteoclast differentiation.
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http://dx.doi.org/10.1016/j.bone.2014.11.026DOI Listing
April 2015

[Not Available].

Acta Cardiol Sin 2014 Sep;30(5):485-9

Department of Cardiology, Buddhist Tzu Chi General Hospital; ; Buddhist Tzu Chi University, Hualien, Taiwan.

Unlabelled: Saphenous vein graft (SVG) failure secondary to degeneration can cause significant problems after coronary artery bypass surgery (CABG). Repeat revascularization by percutaneous coronary intervention can be performed after SVG failure but is often associated with less favourable clinical outcome. Treatment for chronic total occlusion (CTO) of native vessels after SVG failure among patients with prior CABG is frequently performed. However, revascularization of CTO vessels in patients with prior CABG may be more complex and require more frequent use of the retrograde approach. Good septal or epicardial collateral channels are usually needed for the retrograde CTO approach. However, suitable native collateral channels may be absent and alternative retrograde routes should be considered. In this case report, we described a patient who had prior CABG and developed recurrent angina after SVG failure. His native CTO lesion was successfully revascularized by using a totally occluded vein graft as a retrograde conduit.

Key Words: Chronic total occlusions; Coronary artery bypass grafts; Percutaneous coronary intervention; Saphenous vein graft.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4834962PMC
September 2014

Delayed Infective Endocarditis with Mycotic Aneurysm Rupture below the Mechanical Valved Conduit after the Bentall Procedure.

Acta Cardiol Sin 2014 Jul;30(4):341-5

Department of Cardiology, Buddhist Tzu Chi General Hospital; ; Buddhist Tzu Chi University, Hualien;

Unlabelled: The Bentall procedure is the gold standard for treating aortic dissection complicated with valvular and ascending aorta disease. Recent results for this procedure have been excellent; nearly 100% of patients remain free of infective endocarditis in long-term follow-up. We report a case of delayed Streptococcus agalactiae infective endocarditis complicated by mycotic aneurysm in a man who had undergone the Bentall procedure with a mechanical valve conduit 15 years previously. The mycotic aneurysm was located in the remnant aortic root, below the mechanical valve conduit, and later ruptured into the right atrium. The patient was treated conservatively and survived the acute period. Later, the aortic root defect was repaired successfully by means of a hybrid technique using a Amplatzer duct occluder.

Key Words: Amplatzer duct occluder; Aortic dissection; Bentall technique; Infective endocarditis; Mycotic aneurysm.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4804998PMC
July 2014

Computed tomography demonstrates abnormalities of contralateral ear in subjects with unilateral sensorineural hearing loss.

Int J Pediatr Otorhinolaryngol 2014 Feb 25;78(2):268-71. Epub 2013 Nov 25.

Department of Otolaryngology, Wake Forest™ School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, United States. Electronic address:

Purpose: Prior studies have associated gross inner ear abnormalities with pediatric sensorineural hearing loss (SNHL) using computed tomography (CT). No studies to date have specifically investigated morphologic inner ear abnormalities involving the contralateral unaffected ear in patients with unilateral SNHL. The purpose of this study is to evaluate contralateral inner ear structures of subjects with unilateral SNHL but no grossly abnormal findings on CT.

Materials And Methods: IRB-approved retrospective analysis of pediatric temporal bone CT scans. 97 temporal bone CT scans, previously interpreted as "normal" based upon previously accepted guidelines by board certified neuroradiologists, were assessed using 12 measurements of the semicircular canals, cochlea and vestibule. The control-group consisted of 72 "normal" temporal bone CTs with underlying SNHL in the subject excluded. The study-group consisted of 25 normal-hearing contralateral temporal bones in subjects with unilateral SNHL. Multivariate analysis of covariance (MANCOVA) was then conducted to evaluate for differences between the study and control group.

Results: Cochlea basal turn lumen width was significantly greater in magnitude and central lucency of the lateral semicircular canal bony island was significantly lower in density for audiometrically normal ears of subjects with unilateral SNHL compared to controls.

Conclusion: Abnormalities of the inner ear were present in the contralateral audiometrically normal ears of subjects with unilateral SNHL. These data suggest that patients with unilateral SNHL may have a more pervasive disease process that results in abnormalities of both ears. The findings of a cochlea basal turn lumen width disparity >5% from "normal" and/or a lateral semicircular canal bony island central lucency disparity of >5% from "normal" may indicate inherent risk to the contralateral unaffected ear in pediatric patients with unilateral sensorineural hearing loss.
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http://dx.doi.org/10.1016/j.ijporl.2013.11.020DOI Listing
February 2014

Trabecular bone structural parameters evaluated using dental cone-beam computed tomography: cellular synthetic bones.

Biomed Eng Online 2013 Nov 9;12:115. Epub 2013 Nov 9.

School of Dentistry, College of Medicine, China Medical University, Taichung 404, Taiwan.

Objective: This study compared the adequacy of dental cone beam computed tomography (CBCT) and micro computed tomography (micro-CT) in evaluating the structural parameters of trabecular bones.

Methods: The cellular synthetic bones in 4 density groups (Groups 1-4: 0.12, 0.16, 0.20, and 0.32 g/cm3) were used in this study. Each group comprised 8 experimental specimens that were approximately 1 cm3. Dental CBCT and micro-CT scans were conducted on each specimen to obtain independent measurements of the following 4 trabecular bone structural parameters: bone volume fraction (BV/TV), specific bone surface (BS/BV), trabecular thickness (Tb.Th.), and trabecular separation (Tb.Sp.). Wilcoxon signed ranks tests were used to compare the measurement variations between the dental CBCT and micro-CT scans. A Spearman analysis was conducted to calculate the correlation coefficients (r) of the dental CBCT and micro-CT measurements.

Results And Conclusion: Of the 4 groups, the BV/TV and Tb.Th. measured using dental CBCT were larger compared with those measured using micro-CT. By contrast, the BS/BV measured using dental CBCT was significantly less compared with those measured using micro-CT. Furthermore, in the low-density groups (Groups 1 and 2), the Tb.Sp. measured using dental CBCT was smaller compared with those measured using micro-CT. However, the Tb.Sp. measured using dental CBCT was slightly larger in the high-density groups (Groups 3 and 4) than it was in the low density groups. The correlation coefficients between the BV/TV, BS/BV, Tb.Th., and Tb.Sp. values measured using dental CBCT and micro-CT were 0.9296 (p < .001), 0.8061 (p < .001), 0.9390 (p < .001), and 0.9583 (p < .001), respectively. Although the dental CBCT and micro-CT approaches exhibited high correlations, the absolute values of BV/TV, BS/BV, Tb.Th., Tb.Sp. differed significantly between these measurements. Additional studies must be conducted to evaluate using dental CBCT in clinical practice.
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http://dx.doi.org/10.1186/1475-925X-12-115DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3826852PMC
November 2013

Imaging-guided radiofrequency ablation of cystic renal neoplasms.

AJR Am J Roentgenol 2013 Jun;200(6):1365-9

Department of Radiology, Wake Forest Baptist Medical Center, Medical Center Blvd, 3rd Fl MRI, Winston-Salem, NC 27157-1088, USA.

Objective: The purpose of this article is to determine whether percutaneous radiofrequency ablation (RFA) is effective and safe for the treatment of cystic renal neoplasms.

Materials And Methods: This is a retrospective review of imaging-guided RFA of Bosniak III and IV cysts from one institution. Thirty-eight subjects (19 men and 19 women; mean age, 71 years; age range, 46-95 years) underwent RFA of 40 cystic neoplasms (Bosniak III, n = 25; Bosniak IV, n = 15). Percutaneous biopsy was performed in 90% (36/40) of lesions. For patients with imaging follow-up of at least 1 year (n = 21), the mean duration of surveillance was 2.8 years (range, 1-6.5 years). The electronic medical record was reviewed for complications related to the procedure. Estimated glomerular filtration rate (GFR) was measured before RFA and at the last follow-up visit more than 6 months after the RFA session.

Results: According to percutaneous biopsy, 61.1% (22/36) of lesions were malignant, and 38.9% (14/36) of biopsies were inconclusive. There was no local tumor progression, and no subjects developed metastatic disease. One subject developed a new solid renal mass during the course of follow-up. Minor complications occurred in 5.3% (2/38) of ablations and included dysuria and mild hydronephrosis related to a blood clot in the ureter. There was one major complication (2.6%), a case of flash pulmonary edema. On average, estimated GFR decreased by 2.5 mL/min/1.73 m(2).

Conclusion: Imaging-guided RFA is an effective and safe treatment of Bosniak III and IV cystic renal neoplasms with outcomes comparable to those of surgical therapies.
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http://dx.doi.org/10.2214/AJR.12.9336DOI Listing
June 2013

Computed tomography supports histopathologic evidence of vestibulocochlear sexual dimorphism.

Int J Pediatr Otorhinolaryngol 2013 Jul 17;77(7):1118-22. Epub 2013 May 17.

Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, United States.

Objective: To investigate whether the effects of sex (male/female) that have been demonstrated in the pathology literature using 0.1 mm histopathologic slices are measurable and statistically significant using high-resolution (0.625 mm slice) computed tomography (CT).

Methods: IRB-approved retrospective analysis of high-resolution "normal" CT temporal bone images in pediatric subjects (0-18 years) using comparative anatomic measurements between males and females obtained from the semicircular canals, cochlea and vestibule as follows: (1) lateral semicircular canal (LSCC) bony island width, (2) superior semicircular canal (SSCC) bony island width, (3) central lucency of the LSCC bony island, (4) coronal cochlear height, (5) axial cochlear height, (6) cochlear length, (7) cochlea basal turn lumen width, (8) cochlear aperture width, (9) cochlear aperture height, (10) vestibular length, (11) vestibular width, and (12) coronal vestibule oblique diameter.

Results: Eighteen females (36 ears) and twenty males (36 ears) were included in the study. Independent-samples t-tests revealed statistically significant differences in measurements for females and males as follows (differences reported as a percentage and as an absolute difference (AD) in mm): (1) vestibular width was 4.2% (0.13 mm AD) smaller in females (mean ± SD; 3.0 ± 0.27) compared to males (mean ± SD; 3.2 ± 0.25) [t(70) = 2.083, p = 0.041]; (2) cochlear length was 3.9% (.23 mm AD) smaller in females (mean ± SD; 5.8 ± 0.32) compared to males (mean ± SD; 6.0 ± 0.40) [t(70)=2.660, p = 0.010]; (3) cochlear aperture height was 11.6% (0.13 mm AD) smaller in females (mean ± SD; 1.0 ± 0.18) compared to males (mean ± SD; 1.2 ± 0.22) [t(70)=2.549, p = 0.013]; and (4) coronal cochlear height was 11.4% (0.55 mm AD) smaller in females (mean ± SD; 4.8 ± 0.58) compared to males (mean ± SD; 5.4 ± 0.48) [t(68) = 4.270, p < 0.005].

Conclusion: Sexual dimorphism of inner ear structures may contribute to variability in reported normative and pathologic measurements of inner ear structures. This variability must be taken into consideration when designing future research studies to investigate inner ear structures and for drawing accurate conclusions about possible inner ear morphologic abnormalities associated with SNHL compared to controls.
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http://dx.doi.org/10.1016/j.ijporl.2013.04.013DOI Listing
July 2013

Biomechanical investigation of thread designs and interface conditions of zirconia and titanium dental implants with bone: three-dimensional numeric analysis.

Int J Oral Maxillofac Implants 2013 Mar-Apr;28(2):e64-71

School of Dentistry, China Medical University, Taichung, Taiwan.

Purpose: Bone stress and interfacial sliding at the bone-implant interface (BII) were analyzed in zirconia and titanium implants with various thread designs and interface conditions (bonded BII and contact BIIs with different frictional coefficients) for both conventional and immediately loaded treatments.

Materials And Methods: A total of 18 finite element models comprising two implant materials (zirconia and titanium), three thread designs (different shapes and pitches), and three interface conditions (bonded and contact BIIs) were analyzed to assess the effects on bone stresses and on sliding at the BII. The material properties of the bone model were anisotropic, and a lateral force of 130 N was applied as the loading condition.

Results: In the immediately loaded implant, the stress was highly concentrated at one site of the peri-implant bone. The peak bone stress was more than 20% lower in zirconia implants than in titanium implants for a bonded BII and 14% to 20% lower for a contact BII. The bone stresses did not differ significantly between implants with V-shaped threads and square threads. However, sliding at the BII was more than 25% lower with square-thread implants than with V-shaped-thread implants for titanium implants and 36% lower for zirconia implants. Reducing the thread size and pitch in cortical bone (via two V-shaped threads with different pitches) decreased the bone stress by 13%. Increasing the frictional coefficient reduced sliding at the BII in both zirconia and titanium implants.

Conclusions: As an implant material, zirconia can reduce the bone stress in the crestal cortical region. Bone stress and sliding at the BII are heavily dependent on the thread design and the frictional coefficient at the BII of immediately loaded implants.
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http://dx.doi.org/10.11607/jomi.2131DOI Listing
February 2014

Renal function outcomes for multifocal renal neoplasms managed by radiofrequency ablation.

Cardiovasc Intervent Radiol 2013 Oct 30;36(5):1329-35. Epub 2013 Jan 30.

Department of Radiology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC, 27157, USA,

Purpose: To evaluate renal function changes related to radiofrequency ablation (RFA) for the treatment of multifocal renal neoplasms.

Methods: This is an institutional review board-approved, Health Insurance Portability and Accountability Act compliant retrospective study of all patients treated with computed tomography guided RFA for multifocal renal neoplasms at one institution. Fifty-seven subjects, mean age 70 (range 37-88) years, underwent RFA of 169 renal neoplasms (average size 2.0 cm). Subjects had between 2 and 8 (mean 2.96) neoplasms ablated. Estimated glomerular filtration rate (eGFR) was measured before and after RFA. Complications related to RFA were recorded.

Results: eGFR decreased on average of 4.4 % per tumor treated and 6.7 % per ablation session (average 1.76 tumors treated per session). For subjects with the largest neoplasm measuring >3 cm, eGFR decreased an average of 14.5 % during the course of their treatment. If the largest neoplasm measured 2-3 cm, eGFR decreased an average of 7.7 %, and if the largest neoplasm measured <2 cm, eGFR decreased an average of 3.8 %. Subjects with reduced baseline renal function were more likely to have a greater decline in eGFR after RFA. There was a minor complication rate of 6.3 % (6 of 96 sessions), none of which required treatment, and a major complication rate of 4.2 % (4 of 96 sessions).

Conclusion: RFA for the treatment of multifocal renal neoplasms results in mild decline of renal function.
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http://dx.doi.org/10.1007/s00270-013-0563-9DOI Listing
October 2013

Predicting cortical bone strength from DXA and dental cone-beam CT.

PLoS One 2012 30;7(11):e50008. Epub 2012 Nov 30.

School of Dentistry, College of Medicine, China Medical University, Taichung, Taiwan.

Objective: This study compared the capabilities of dual-energy X-ray absorptiometry (DXA) and dental cone-beam computed tomography (CBCT) for predicting the cortical bone strength of rat femurs and tibias.

Materials And Methods: Specimens of femurs and tibias obtained from 14 rats were first scanned with DXA to obtain the areal bone mineral density (BMD) of the midshaft cortical portion of the bones. The bones were then scanned using dental CBCT to measure the volumetric cortical bone mineral density (vCtBMD) and the cross-sectional moment of inertia (CSMI) for calculating the bone strength index (BSI). A three-point bending test was conducted to measure the fracture load of each femur and tibia. Bivariate linear Pearson analysis was used to calculate the correlation coefficients (r values) among the CBCT measurements, DXA measurements, and three-point bending parameters.

Results: The correlation coefficients for the associations of the fracture load with areal BMD (measured using DXA), vCtBMD (measured using CBCT), CSMI (measured using CBCT), and BSI were 0.585 (p = 0.028) and 0.532 (p = 0.050) (for the femur and tibia, respectively), 0.638 (p = 0.014) and 0.762 (p = 0.002), 0.778 (p = 0.001) and 0.792 (p<0.001), and 0.822 (p<0.001) and 0.842 (p<0.001), respectively.

Conclusions: CBCT was found to be superior to DXA for predicting cortical bone fracture loads in rat femurs and tibias. The BSI, which is a combined index of densitometric and geometric parameters, was especially useful. Further clinical studies are needed to validate the predictive value of BSI obtained from CBCT and should include testing on human cadaver specimens.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0050008PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3511426PMC
May 2013

Incidence and clinical significance of zygomaticomaxillary complex fracture involving the temporomandibular joint with emphasis on trismus.

Kaohsiung J Med Sci 2012 Jun 3;28(6):336-40. Epub 2012 Apr 3.

Department of Oral and Maxillofacial Surgery, China Medical University Hospital, Taichung, Taiwan.

Trismus is frequently a sequel of temporomandibular joint (TMJ) involvement in a zygomaticomaxillary complex (ZMC) fracture. Although trismus is commonly observed in patients with ZMC fracture, continuous follow-up examinations of their degree of mouth opening have rarely been documented. The aim of this retrospective study was to determine the incidence and clinical significance of ZMC fracture involving the glenoid fossa or articular eminence of the TMJ with an emphasis on trismus. The medical and computed tomography (CT) imaging data of 28 patients with ZMC fracture treated by oral and maxillofacial surgeons (OMFSs) (OMFS group) and 174 patients with ZMC fracture treated by surgeons other than OMFSs (non-OMFS group) between May 2002 and May 2006 were reviewed. Maximal interincisal opening (MIO) less than 35 mm or three-finger width was considered limited mouth opening and indicative of trismus. Preoperative CT imaging data indicated that about 64% (18/28) and 50% (87/174) of the patients in the OMFS and non-OMFS groups, respectively, had a ZMC fracture involving the TMJ. Among these OMFS patients, 17 (94.40%) patients had limited mouth opening (MIO range, 7-33 mm) preoperatively, which improved markedly postoperatively. Among the non-OMFS patients with such fractures, 42 (48.3%) patients had trismus preoperatively and two retained trismus postoperatively. Lack of proper preoperative CT images, inadequate postoperative follow-up protocol, and/or neglect by patients and medical staff could influence the outcomes of ZMC fracture involving the TMJ. We make recommendations for reducing the risk of complications subsequent to ZMC fracture involving the TMJ.
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http://dx.doi.org/10.1016/j.kjms.2011.11.016DOI Listing
June 2012

Adnexal masses in female pediatric patients.

AJR Am J Roentgenol 2012 May;198(5):W426-31

Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.

Objective: This article reviews the range of adnexal masses that present in pediatric females. The preferred imaging modalities, the appearance of the normal ovaries, and the epidemiology of ovarian diseases and abnormalities are discussed. The illustrated abnormalities include simple and complex ovarian and paraovarian cysts, neoplasms, ovarian torsion, ectopic pregnancy, and tuboovarian abscess, with attention to the imaging features and vascular flow patterns that help distinguish surgical from nonsurgical cases, malignant from benign lesions, and ovarian abnormalities from mimickers.

Conclusion: The critical clinical questions to the radiologist in the setting of adnexal lesions are the site of origin, benign versus malignant features, and presence of infection or abscess. Pairing clinical presentation and imaging findings will direct appropriate management, whether it is reassurance, follow-up imaging, or surgery.
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http://dx.doi.org/10.2214/AJR.11.7920DOI Listing
May 2012

Microcomputed tomography analysis of particular autogenous bone graft in sinus augmentation at 5 months: differences on bone mineral density and 3D trabecular structure.

Clin Oral Investig 2013 Mar 25;17(2):535-42. Epub 2012 Apr 25.

School of Dentistry, China Medical University, 91 Hsueh-Shih Road, 40402, Taichung, Taiwan.

Objectives: This study investigated the effects of gender on the three-dimensional (3D) bone mineral density (BMD) and micromorphology of the trabeculae of matured autogenous bone grafts after sinus floor augmentation, and compared them to those of adjacent native bone.

Materials And Methods: Ten bone biopsy samples were removed from the implant placement areas of patients who had received second-stage sinus floor augmentation, and analyzed by microcomputed tomography. BMD phantoms with two calcium hydroxyapatite densities (0.25 and 0.75 g/cm(3)) were used to determine the BMD of the grafted and native bone samples. The 3D structural parameters of the trabeculae, including percentage of bone volume (bone volume/tissue volume, BV/TV), trabecular thickness (Tb.Th), trabecular number, trabecular separation, trabecular pattern factor (Tb.Pf), and structure model index, were analyzed between males and females and between grafted bone and native bone.

Results: No significant gender-specific differences in BMD and 3D trabecular structure of either native or grafted bone were found (P > 0.05). Compared to the adjacent native bone, the autogenous grafted bone exhibited lower BV/TV and Tb.Th as well as a higher Tb.Pf (P < 0.05). Additionally, there was a weak positive correlation between the Tb.Th values of grafted and native bone (R (2) = 0.58).

Conclusions: In the maxillary sinus, autogenous grafted bone exhibited lower BV/TV, Tb.Th, and trabecular connectivity than the adjacent native bone. No significant gender-specific differences were found for either the BMD or 3D trabecular structure of grafted bone.

Clinical Relevance: After bone remodeling, autogenous grafted bone revealed different 3D trabecular structure as compared to native bone.
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http://dx.doi.org/10.1007/s00784-012-0725-1DOI Listing
March 2013

Access to radiologic reports via a patient portal: clinical simulations to investigate patient preferences.

J Am Coll Radiol 2012 Apr;9(4):256-63

Department of Radiology, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, USA.

Purpose: The aim of this study was to determine (1) the patient-preferred timing characteristics of a system for online patient access to radiologic reports and (2) patient resource needs and preferences after exposure to reports.

Methods: Adult outpatients from a single imaging center completed researcher-administered electronic questionnaires. Participants were exposed to 3 simulated clinical scenarios and asked to answer questions on the basis of what they thought they would do in each. Scenarios included symptomatology and written radiology reports that were nearly normal, seriously abnormal, and indeterminate, with reports containing typical medical terminology. Participants were asked about preferred timing for online access to reports, communication methods, educational resources, and alternative formats. McNemar's test correlated proportions and generalized estimating equations were used to evaluate responses.

Results: Participants (n = 53) most often preferred immediate access to reports: 32 (60.2%) for the nearly normal scenario, 25 (47.2%) for the seriously abnormal scenario, and 24 (45.3%) for the indeterminate scenario. Three-day delayed access was next most commonly preferred: 15 (28.3%), 19 (35.8%), and 19 (35.8%), respectively. Forty-two participants (79.2%) preferred the portal method of notification over ways they have historically gotten results, with an increased proportion being satisfied with it overall (P < .04). Most would use a variety of educational resources and found alternative lay language conclusions and hyperlinks helpful.

Conclusions: Some outpatients want immediate online access to complete, written radiologic reports and would use multiple resources to understand report contents. Effects of immediate access on provider workflow and on anxiety and autonomy among a diverse population of patients still need to be studied.
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http://dx.doi.org/10.1016/j.jacr.2011.12.023DOI Listing
April 2012

Three-dimensional bone structure and bone mineral density evaluations of autogenous bone graft after sinus augmentation: a microcomputed tomography analysis.

Clin Oral Implants Res 2012 Sep 15;23(9):1098-103. Epub 2011 Aug 15.

School of Dentistry, China Medical University, 91 Hsueh-Shih Road, Taichung, Taiwan.

Objective: The purpose of this study was to determine the relationships and differences in three-dimensional (3D) bone mineral density (BMD) and microtrabecular structures between autogenous bone grafts and their adjacent native bone after a healing period following maxillary sinus augmentation.

Materials And Methods: Nine rod-shaped human bone biopsy samples were taken from patients receiving two-stage sinus augmentation therapy in implantation areas and analyzed using microcomputed tomography (micro-CT). Before micro-CT scanning, two BMD phantoms were placed near to the bone biopsy samples for executing BMD calculations of the grafted and native bone samples. In addition, 3D structural parameters of the trabeculae were analyzed for both the grafted and native bone, including percentage of bone volume [bone volume (BV)/tissue volume (TV)], bone-specific surface [bone surface (BS)/BV], trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), trabecular pattern factor (Tb.Pf), and structure model index (SMI).

Results: No significant correlations with regard to BMD and trabecular-structure parameters were found between native bone and grafted bone; however, BS/BV and Tb.Pf were higher and Tb.Th and Tb.Sp were 37.35% and 12.74% lower in grafted bone than in native bone. For grafted bone, there were significant correlations (P < 0.05) between BMD and BV/TV, and Tb.N.

Conclusions: When using autogenous bone as a graft material, BMD and micromorphological conditions of grafted bone were not influenced by the condition of the native bone in the maxilla. Differences were found in surface complexity, trabecular thickness, trabecular separation, and the connectivity of trabeculae between grafted and native bone. The BMD in grafted bone was affected by the quantity of the trabeculae.
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http://dx.doi.org/10.1111/j.1600-0501.2011.02273.xDOI Listing
September 2012