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1.
Ann Surg ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39258375

RESUMO

OBJECTIVE: To investigate the long-term outcomes of patients with combined primary sclerosing cholangitis/inflammatory bowel disease (PSC-IBD) undergoing both liver transplantation (LT) and total abdominal colectomy (TAC). SUMMARY BACKGROUND DATA: The fraction of patients with PSC-IBD that require both LT and TAC is small, thereby limiting significant conclusions regarding long-term outcomes. METHODS: Adult and pediatric patients from nine centers from the US IBD Surgery Collaborative who underwent staged LT and TAC for PSC-IBD were included. Long-term outcomes, including survival, were assessed. RESULTS: Among 127 patients, 66 underwent TAC-before-LT, with a median time from TAC to LT of 7.9 yrs, while 61 underwent LT-before-TAC, with a median time from LT to TAC of 4.4 years. Median patient survival post TAC was significantly worse in those undergoing LT-before-TAC (16.0 yrs vs. 42.6 yrs, P=0.007), while post LT survival was not impacted by the order of TAC and LT (21.6 yrs vs. 22.0 yrs, P=0.81). Patients undergoing TAC for medically refractory disease had a higher incidence of recurrent PSC (rPSC) (P=0.02) and biliary complications (0.09) compared to those undergoing TAC for oncologic indications. Definitive TAC reconstruction with either end ileostomy or ileal-pouch anal anastomosis (IPAA) did not impact post-LT or post-TAC outcomes. CONCLUSIONS: Long term survival in PSC-IBD was contingent upon progression to LT and was not impacted by the need for TAC. PSC-IBD patients undergoing TAC for medically refractory disease had a higher incidence of rPSC and biliary complications. The use of IPAA in PSC-IBD was a viable alternative to end ileostomy.

2.
J Gastrointest Surg ; 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39181234

RESUMO

BACKGROUND: Failure to rescue after elective surgery is associated with increased healthcare costs. These costs are poorly understood and have not been reported for colorectal surgery. This study aimed to assess the incremental costs of failure to rescue after elective colorectal surgery. METHODS: This was a retrospective study of adult patients identified in the National Inpatient Sample from 2016 to 2019 who underwent an elective colectomy or proctectomy. Patients were stratified into 4 groups: uneventful recovery, successfully rescued, failure to rescue, and died without rescue attempts. "Rescue" was defined as admissions with ≥1 procedure code ≥1 day after the initial procedure. The primary outcome was total admission costs. RESULTS: Of 451,490 admissions for elective colorectal resection, 94.6% had an uneventful recovery, 4.8% were successfully rescued, 0.4% were failure to rescue, and 0.3% died without rescue attempts. The median total hospital cost for the uneventful recovery cohort was $16,751 (IQR, $12,611-$23,116), for the successfully rescued cohort was $42,295 (IQR, $27,959-$67,077), for the failure-to-rescue cohort was $53,182 (IQR, $30,852-$95,615), and for the died without attempted rescue cohort was $29,296 (IQR, $19,812-$45,919). When comparing cost quantiles by regression analysis, failure-to-rescue patients had significantly higher costs than the successfully rescued patients for the last 3 quantiles (fifth quantile [90th percentile], $163,963 vs $106,521; P < .001). CONCLUSION: Across a nationally representative cohort, the median total hospital costs for patients who failed to be rescued were $10,887 more than for those who were successfully rescued. These findings emphasize the importance of shared decision making and medical futility and highlight opportunities for resource optimization after postoperative complications.

3.
Ann Surg Oncol ; 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39138773

RESUMO

Social media has become omnipresent in society, especially given that it enables the rapid and widespread communication of news, events, and information. Social media platforms have become increasingly used by numerous surgical societies to promote meetings and surgical journals to increase the visibility of published content. In September 2020, Annals of Surgical Oncology (ASO) established its Social Media Committee (SMC), which has worked to steadily increase the visibility of published content on social media platforms, namely X (formerly known as Twitter). The purpose of this review is to highlight the 10 ASO original articles with the most engagement on X, based on total number of mentions, since the founding of the SMC. These articles encompass a wide variety of topics from various oncologic disciplines including hepatopancreatobiliary, breast, and gynecologic surgery.

6.
Ann Surg Oncol ; 31(8): 5168-5179, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38717543

RESUMO

BACKGROUND: Many women eligible for breast conservation therapy (BCT) elect unilateral mastectomy (UM) with or without contralateral prophylactic mastectomy (CPM) and cite a desire for "peace of mind." This study aimed to characterize how peace of mind is defined and measured and how it relates to surgical choice. METHODS: Nine databases were searched for relevant articles through 8 October 2023, and data were extracted from articles meeting the inclusion criteria. RESULTS: The inclusion criteria were met by 20 studies. Most were prospective cohort studies (65%, 13/20). In the majority of the studies (72%, 13/18), Non-Hispanic white/Caucasian women comprised 80 % or more of the study's sample. Almost half of the studies used the phrase "peace of mind" in their publication (45%, 9/20), and few directly defined the construct (15%, 3/20). Instead, words representing an absence of peace of mind were common, specifically, "anxiety" (85%, 17/20), "fear" (75%, 15/20), and "concern" (75%, 15/20). Most of the studies (90%, 18/20) measured peace of mind indirectly using questionnaires validated for anxiety, fear, worry, distress, or concern, which were administered at multiple postoperative time points (55%, 11/20). Most of the studies (95%, 18/19) reported at least one statistically significant result showing no difference in peace of mind between BCT, UM, and/or CPM at their latest time of assessment. CONCLUSION: Peace of mind is largely framed around concepts that suggest its absence, namely, anxiety, fear, and concern. Existing literature suggests that peace of mind does not differ among average-risk women undergoing BCT, UM, or CPM. Shared surgical decisions should emphasize at least comparable emotional and/or psychosocial well-being between CPM and breast conservation.


Assuntos
Neoplasias da Mama , Mastectomia , Humanos , Feminino , Neoplasias da Mama/cirurgia , Neoplasias da Mama/psicologia , Mastectomia/psicologia , Ansiedade/psicologia , Ansiedade/prevenção & controle , Medo/psicologia , Mastectomia Profilática/psicologia , Prognóstico
7.
Cancers (Basel) ; 15(24)2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38136397

RESUMO

The modern rectal cancer treatment paradigm offers additional opportunities for organ preservation, most notably via total neoadjuvant therapy (TNT) and consideration for a watch-and-wait (WW) surveillance-only approach. A major barrier to widespread implementation of a WW approach to rectal cancer is the potential discordance between a clinical complete response (cCR) and a pathologic complete response (pCR). In the pre-TNT era, the identification of predictors of pCR after neoadjuvant therapy had been previously studied. However, the last meta-analysis to assess the summative evidence on this important treatment decision point predates the acceptance and dissemination of TNT strategies. The purpose of this systematic review was to assess preoperative predictors of pCR after TNT to guide the ideal selection criteria for WW in the current era. An exhaustive literature review was performed and the electronic databases Embase, Ovid, MEDLINE, PubMed, and Cochrane were comprehensively searched up to 27 June 2023. Search terms and their combinations included "rectal neoplasms", "total neoadjuvant therapy", and "pathologic complete response". Only studies in English were included. Randomized clinical trials or prospective/retrospective cohort studies of patients with clinical stage 2 or 3 rectal adenocarcinoma who underwent at least 8 weeks of neoadjuvant chemotherapy in addition to chemoradiotherapy with pCR as a measured study outcome were included. In this systematic review, nine studies were reviewed for characteristics positively or negatively associated with pCR or tumor response after TNT. The results were qualitatively grouped into four categories: (1) biochemical factors; (2) clinical factors; (3) patient demographics; and (4) treatment sequence for TNT. The heterogeneity of studies precluded meta-analysis. The level of evidence was low to very low. There is minimal data to support any clinicopathologic factors that either have a negative or positive relationship to pCR and tumor response after TNT. Additional data from long-term trials using TNT is critical to better inform those considering WW approaches following a cCR.

8.
Surg Open Sci ; 16: 148-154, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38026825

RESUMO

Background: Successful rescue after elective surgery is associated with increased healthcare costs, but costs vary widely. Treating all rescue events the same may overlook targeted opportunities for improvement. The purpose of this study was to predict high-cost rescue after elective colorectal surgery. Methods: We identified adult patients in the National Inpatient Sample (2016-2021) who underwent elective colectomy or proctectomy. Rescued patients were defined as those who underwent additional major procedures. Three groups were stratified: 1) uneventful recovery; 2) Low-cost rescue; 3) High-cost rescue. Multivariable Poisson regression was used to identify preoperative clinical predictors of high-cost versus low-cost rescue. Results: We identified 448,590 elective surgeries, and rescued patients composed 4.8 %(21,635) of the total sample. The median increase in costs in rescued patients was $25,544(p < 0.001). Median total inpatient costs were $95,926 in the most expensive rescued versus $34,811 in the less expensive rescued versus $16,751 in the uneventfully discharged(p < 0.001). When comparing the secondary procedures between the less expensive and most expensive rescued groups, the most expensive had an increased proportion of reoperation (73.4 % versus 53.0 %,p < 0.001). When controlling for other factors and stratification by congestive heart failure due to an interaction effect, a reoperation was independently associated with high-cost rescue (RR with CHF = 3.29,95%CI:2.69-4.04; RR without CHF = 2.29,95%CI:1.97-2.67). Conclusions: High-cost rescue after colorectal surgery is associated with disproportionately greater healthcare utilization and reoperation. For cost-conscious care, preemptive strategies that reduce reoperation-related complications can be prioritized.

9.
Artigo em Inglês | MEDLINE | ID: mdl-35990197

RESUMO

Purpose: Intracranial hemorrhage (ICH) is characterized as bleeding into the brain tissue, intracranial space, and ventricles and is the second most disabling form of stroke. Hematoma expansion (HE) following ICH has been correlated with significant neurological decline and death. For early detection of patients at risk, deep learning prediction models were developed to predict whether hematoma due to ICH will expand. This study aimed to explore the feasibility of HE prediction using a radiomic approach to help clinicians better stratify HE patients and tailor intensive therapies timely and effectively. Materials and Methods: Two hundred ICH patients with known hematoma evolution, were enrolled in this study. An open-source python package was utilized for the extraction of radiomic features from both non-contrast computed tomography (NCCT) and magnetic resonance imaging (MRI) scans through characterization algorithms. A total of 99 radiomic features were extracted and different features were selected for network inputs for the NCCT and MR models. Seven supervised classifiers: Support Vector Machine, Naïve Bayes, Decision Tree, Random Forest, Logistic Regression, K-Nearest Neighbor and Multilayer Perceptron were used to build the models. A training:testing split of 80:20 and 20 iterations of Monte Carlo cross validation were performed to prevent overfitting and assess the variability of the networks, respectively. The models were fed training datasets from which they learned to classify the data based on pre-determined radiomic categories. Results: The highest sensitivity among the NCCT classifier models was seen with the support vector machine (SVM) and logistic regression (LR) of 72 ± 0.3% and 73 ± 0.5%, respectively. The MRI classifier models had the highest sensitivity of 68 ± 0.5% and 72 ± 0.5% for the SVM and LR models, respectively. Conclusions: This study indicates that the NCCT radiomics model is a better predictor of HE and that SVM and LR classifiers are better predictors of HE due to their more cautious approach indicated by a higher sensitivity metric.

11.
PM R ; 14(7): 786-792, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34181824

RESUMO

BACKGROUND: Falls are the leading cause of fatal injury, and the most common cause of nonfatal trauma, among older adults. However, patient perspectives on preferences for obtaining fall education are not well reported. OBJECTIVE: To identify components of successful fall prevention education. DESIGN: Prospective qualitative study. SETTING: Tertiary care center; institutional. PARTICIPANTS: Adults aged 65 years or older with a history of falls who received services from inpatient trauma or outpatient geriatric services. INTERVENTIONS: One-hour face-to-face semistructured interview. MAIN OUTCOME MEASURE: Semistructured interviews sought to determine participants' history of fall education and perceived strengths and weaknesses of various formats of fall education. RESULTS: Nearly all participants (9/10) indicated they had not received fall prevention education of any kind. Many participants (6/10) reported that, despite not receiving any formal education about falls, they had either given or received information about falls from other older adults in their communities. Participants indicated that framing fall education as a part of healthy aging would be more desirable and mentioned involving participants' families as part of the education. The majority of participants (7/10) suggested fall education be delivered through in-person discussion with providers, and most (9/10) indicated this would provide a personalized approach with opportunity for questions. Participants specified fall education should consist of both environmental modifications (5/10) and awareness of one's surroundings (4/10). CONCLUSIONS: Despite histories of falls, nearly all participants reported they had not received formal fall education. However, many indicated they received fall information informally through their communities. Participants agreed successful fall prevention education would be delivered in an empowering way by a trusted member of the care team.


Assuntos
Pacientes Internados , Poder Psicológico , Idoso , Humanos , Estudos Prospectivos , Pesquisa Qualitativa
12.
J Surg Educ ; 78(2): 405-411, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32863175

RESUMO

OBJECTIVES: Surgery residents have few opportunities to work closely with attending surgeons or conduct research during clinical time. We hypothesized that a mentorship elective with a required research project would benefit residents' career development, including their personal connections with faculty mentors, and would help them build their academic portfolio. DESIGN: We created a mentorship elective designed as a one-on-one apprenticeship. Completion of a scholarly project was a core component of the elective. Residents, faculty, and the most senior resident ('non-mentee') on the same service as the elective resident were interviewed after the completion of their rotation. SETTING: University-based surgery residency at Boston Medical Center, Boston, MA. PARTICIPANTS: All 5 residents in postgraduate year 4 (PGY-4) participated in the mentorship elective during the 2019 to 2020 academic year. Residents identified their faculty mentor. All mentees (5/5), most mentors (4/5), and all non-mentees (4/4) were interviewed. RESULTS: All mentees reported interacting with their mentor daily, performing clinical duties or discussing their research project. For mentees, the top factor when selecting their mentor was the mentor's clinical expertise, and the most valuable aspect of the rotation was developing a relationship with their mentor. All mentors responded that their mentee gained an understanding of running an academic surgical practice and developed research skills. Four of 5 mentees completed critical portions of their scholarly project during the elective with one publishing in a peer-reviewed journal, 2 having their work accepted to a national conference, and one creating vascular surgery educational videos. All stated the elective was valuable. CONCLUSIONS: A structured apprenticeship rotation allowed for closer relationships with attending surgeons and increased the scholarly achievement of PGY-4 surgery residents. We provide an example of how to incorporate a successful elective rotation into the surgery curriculum that strengthens resident career development and research productivity.


Assuntos
Internato e Residência , Cirurgiões , Boston , Currículo , Humanos , Mentores , Procedimentos Cirúrgicos Vasculares
13.
Am J Surg ; 221(1): 155-161, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32758359

RESUMO

BACKGROUND: The purpose of this study was to determine whether racial or other demographic characteristics were associated with declining surgery for early stage gastric cancer. METHODS: Patients with clinical stage I-II gastric adenocarcinoma were identified from the NCDB. Multivariable logistic models identified predictors for declining resection. Patients were stratified based on propensity scores, which were modeled on the probability of declining. Overall survival was evaluated using the Kaplan-Meier method. RESULTS: Of 11,326 patients, 3.68% (n = 417) declined resection. Patients were more likely to refuse if they were black (p < 0.001), had Medicaid or no insurance (p < 0.001), had shorter travel distance to the hospital (p < 0.001) or were treated at a non-academic center (p = 0.001). After stratification, patients who declined surgery had worse overall survival (all strata, p < 0.001). CONCLUSIONS: Racial and sociodemographic disparities exist in the treatment of potentially curable gastric cancer, with patients who decline recommended surgery suffering worse overall survival.


Assuntos
Adenocarcinoma/cirurgia , Asiático/estatística & dados numéricos , Negro ou Afro-Americano/estatística & dados numéricos , Neoplasias Gástricas/cirurgia , Recusa do Paciente ao Tratamento/estatística & dados numéricos , População Branca/estatística & dados numéricos , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Demografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Retrospectivos , Fatores Socioeconômicos , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Taxa de Sobrevida , Estados Unidos
14.
Gerontol Geriatr Med ; 6: 2333721420967884, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33173805

RESUMO

BACKGROUND: Falls are the leading cause of fatal injury, and most common cause of non-fatal trauma, among older adults. We sought to elicit older patient's perspectives on fall risks for the general population as well as contributions to any personal falls to identify opportunities to improve fall education. METHODS: Ten patients with a history of falls from inpatient trauma and outpatient geriatric services were interviewed. Transcripts were analyzed independently by five individuals using triangulation and constant comparison (NVivo11, QSR International) to compare fall risks to fall causes. RESULTS: All patients reported that either they (9/10 participants) or someone they knew (8/10) had fallen. Despite this, only two personally worried about falling. Patient perceptions of fall risks fell into seven major themes: physiologic decline (8/10); underestimating limitations (7/10); environmental hazards (7/10), lack of awareness/rushing (4/10), misuse/lack of walking aids (3/10); positional transitions (2/10), and improper footwear (1/10). In contrast, the most commonly reported causes of personal falls were lack of awareness/rushing (7/10), environmental hazards (3/10), misuse/lack of walking aids (2/10), improper footwear (2/10), physiologic decline (2/10), underestimating limitations (1/10) and positional transitions (1/10). In general tended to attribute their own falls to their surroundings and were less likely to attribute physical or psychological limitations. CONCLUSION: Despite participants identifying falls as a serious problem, they were unlikely to worry about falling themselves. Participants were able to identify common fall risks. However, when speaking about personal experience, they were more likely to blame environmental hazards or rushing, and minimized the role of physiologic decline and personal limitations.

15.
J Hand Surg Am ; 45(11): 1091.e1-1091.e4, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32238279

RESUMO

Aeromonas veronii, a bacterium found in freshwater, is an unusual pathogen in healthy patients. We present a case report of a rare, aggressive subtype in a young, immunocompetent individual. History of injury in an aquatic environment and culture data are key for identification of the causal agent and should dictate acute clinical management and antibiotic therapy. Coverage should include cephalosporins, quinolones, or sulfas if Aeromonas is suspected, and adjusted depending on culture and sensitivity. Early surgical exploration, incision and drainage, and appropriate antimicrobial therapy are the cornerstones for successful treatment of these aggressive, sometimes life-threatening infections.


Assuntos
Aeromonas , Infecções por Bactérias Gram-Negativas , Infecções dos Tecidos Moles , Aeromonas veronii , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Humanos , Infecções dos Tecidos Moles/diagnóstico , Infecções dos Tecidos Moles/tratamento farmacológico , Extremidade Superior
16.
Neurobiol Learn Mem ; 155: 208-215, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30081153

RESUMO

Sleep benefits memory in young adults, and this effect may be particularly strong for representations associated with negative emotion. Many aspects of sleep important for memory consolidation change with aging, particularly by middle age, suggesting that sleep-related consolidation may be reduced. However, the influence of sleep on memory has rarely been investigated in a middle-aged population. In the current study, young and middle-aged adults viewed negative and neutral pictures and underwent a recognition test after sleep or wake. Subjective emotional reactivity was also measured. Compared to waking, sleep benefited memory in young adults. Performance did not differ between sleep and wake groups in middle-aged adults, and it matched the level of young adults who slept. The effect of sleep versus wake was not influenced by memory valence in either age group. These results suggest the relative influence of sleep compared to wake on memory declines with aging, specifically by middle age, and that this decline extends to negative memory.


Assuntos
Envelhecimento/psicologia , Emoções/fisiologia , Memória/fisiologia , Sono , Adolescente , Adulto , Fatores Etários , Feminino , Humanos , Masculino , Consolidação da Memória/fisiologia , Pessoa de Meia-Idade , Reconhecimento Psicológico/fisiologia , Adulto Jovem
17.
Quant Imaging Med Surg ; 7(6): 623-635, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29312867

RESUMO

BACKGROUND: To assess the volumetric measurement of small (≤1 cm) nonsolid nodules with computed tomography (CT), focusing on the interaction of state of the art iterative reconstruction (IR) methods and dose with nodule densities, sizes, and shapes. METHODS: Twelve synthetic nodules [5 and 10 mm in diameter, densities of -800, -630 and -10 Hounsfield units (HU), spherical and spiculated shapes] were scanned within an anthropomorphic phantom. Dose [computed tomography scan dose index (CTDIvol)] ranged from standard (4.1 mGy) to below screening levels (0.3 mGy). Data was reconstructed using filtered back-projection and two state-of-the-art IR methods (adaptive and model-based). Measurements were extracted with a previously validated matched filter-based estimator. Analysis of accuracy and precision was based on evaluation of percent bias (PB) and the repeatability coefficient (RC) respectively. RESULTS: Density had the most important effect on measurement error followed by the interaction of density with nodule size. The nonsolid -630 HU nodules had high accuracy and precision at levels comparable to solid (-10 HU) nonsolid, regardless of reconstruction method and with CTDIvol as low as 0.6 mGy. PB was <5% and <11% for the 10- and 5-mm in nominal diameter -630 HU nodules respectively, and RC was <5% and <12% for the same nodules. For nonsolid -800 HU nodules, PB increased to <11% and <30% for the 10- and 5-mm nodules respectively, whereas RC increased slightly overall but varied widely across dose and reconstruction algorithms for the 5-mm nodules. Model-based IR improved measurement accuracy for the 5-mm, low-density (-800, -630 HU) nodules. For other nodules the effect of reconstruction method was small. Dose did not affect volumetric accuracy and only affected slightly the precision of 5-mm nonsolid nodules. CONCLUSIONS: Reasonable values of both accuracy and precision were achieved for volumetric measurements of all 10-mm nonsolid nodules, and for the 5-mm nodules with -630 HU or higher density, when derived from scans acquired with below screening dose levels as low as 0.6 mGy and regardless of reconstruction algorithm.

18.
Neurobiol Aging ; 45: 178-189, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27459938

RESUMO

Age-related memory decline has been proposed to result partially from impairments in memory consolidation over sleep. However, such decline may reflect a shift toward selective processing of positive information with age rather than impaired sleep-related mechanisms. In the present study, young and older adults viewed negative and neutral pictures or positive and neutral pictures and underwent a recognition test after sleep or wake. Subjective emotional reactivity and affect were also measured. Compared with waking, sleep preserved valence ratings and memory for positive but not negative pictures in older adults and negative but not positive pictures in young adults. In older adults, memory for positive pictures was associated with slow wave sleep. Furthermore, slow wave sleep predicted positive affect in older adults but was inversely related to positive affect in young adults. These relationships were strongest for older adults with high memory for positive pictures and young adults with high memory for negative pictures. Collectively, these results indicate preserved but selective sleep-dependent memory processing with healthy aging that may be biased to enhance emotional well-being.


Assuntos
Envelhecimento/fisiologia , Envelhecimento/psicologia , Emoções/fisiologia , Memória/fisiologia , Sono/fisiologia , Idoso , Idoso de 80 Anos ou mais , Demência/etiologia , Feminino , Humanos , Masculino , Consolidação da Memória/fisiologia , Transtornos da Memória/etiologia , Pessoa de Meia-Idade , Transtornos do Humor/etiologia , Fatores de Risco
19.
3D Print Med ; 1(1): 2, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-30050971

RESUMO

BACKGROUND: The effects of reduced radiation dose CT for the generation of maxillofacial bone STL models for 3D printing is currently unknown. Images of two full-face transplantation patients scanned with non-contrast 320-detector row CT were reconstructed at fractions of the acquisition radiation dose using noise simulation software and both filtered back-projection (FBP) and Adaptive Iterative Dose Reduction 3D (AIDR3D). The maxillofacial bone STL model segmented with thresholding from AIDR3D images at 100 % dose was considered the reference. For all other dose/reconstruction method combinations, a "residual STL volume" was calculated as the topologic subtraction of the STL model derived from that dataset from the reference and correlated to radiation dose. RESULTS: The residual volume decreased with increasing radiation dose and was lower for AIDR3D compared to FBP reconstructions at all doses. As a fraction of the reference STL volume, the residual volume decreased from 2.9 % (20 % dose) to 1.4 % (50 % dose) in patient 1, and from 4.1 % to 1.9 %, respectively in patient 2 for AIDR3D reconstructions. For FBP reconstructions it decreased from 3.3 % (20 % dose) to 1.0 % (100 % dose) in patient 1, and from 5.5 % to 1.6 %, respectively in patient 2. Its morphology resembled a thin shell on the osseous surface with average thickness <0.1 mm. CONCLUSION: The residual volume, a topological difference metric of STL models of tissue depicted in DICOM images supports that reduction of CT dose by up to 80 % of the clinical acquisition in conjunction with iterative reconstruction yields maxillofacial bone models accurate for 3D printing.

20.
Int J Cardiovasc Imaging ; 30(6): 1181-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24839136

RESUMO

Coronary computed tomography angiography (CCTA) contrast opacification gradients, or transluminal attenuation gradients (TAG) offer incremental value to predict functionally significant lesions. This study introduces and evaluates an automated gradients software package that can potentially supplant current, labor-intensive manual TAG calculation methods. All 60 major coronary arteries in 20 patients who underwent a clinically indicated single heart beat 320 × 0.5 mm detector row CCTA were retrospectively evaluated by two readers using a previously validated manual measurement approach and two additional readers who used the new automated gradient software. Accuracy of the automated method against the manual measurements, considered the reference standard, was assessed via linear regression and Bland-Altman analyses. Inter- and intra-observer reproducibility and factors that can affect accuracy or reproducibility of both manual and automated TAG measurements, including CAD severity and iterative reconstruction, were also assessed. Analysis time was reduced by 68% when compared to manual TAG measurement. There was excellent correlation between automated TAG and the reference standard manual TAG. Bland-Altman analyses indicated low mean differences (1 HU/cm) and narrower inter- and intra-observer limits of agreement for automated compared to manual measurements (25 and 36% reduction with automated software, respectively). Among patient and technical factors assessed, none affected agreement of manual and automated TAG measurement. Automated 320 × 0.5 mm detector row gradient software reduces computation time by 68% with high accuracy and reproducibility.


Assuntos
Angiografia Coronária/normas , Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Tomografia Computadorizada Multidetectores/normas , Interpretação de Imagem Radiográfica Assistida por Computador/normas , Software/normas , Automação Laboratorial , Meios de Contraste , Angiografia Coronária/métodos , Estudos de Viabilidade , Feminino , Humanos , Iopamidol , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Validação de Programas de Computador
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