Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
1.
Eur Radiol ; 34(4): 2394-2404, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37735276

RESUMO

OBJECTIVE: To characterize the use and impact of radiation dose reduction techniques in actual practice for routine abdomen CT. METHODS: We retrospectively analyzed consecutive routine abdomen CT scans in adults from a large dose registry, contributed by 95 hospitals and imaging facilities. Grouping exams into deciles by, first, patient size, and second, size-adjusted dose length product (DLP), we summarized dose and technical parameters and estimated which parameters contributed most to between-protocols dose variation. Lastly, we modeled the total population dose if all protocols with mean size-adjusted DLP above 433 or 645 mGy-cm were reduced to these thresholds. RESULTS: A total of 748,846 CTs were performed using 1033 unique protocols. When sorted by patient size, patients with larger abdominal diameters had increased dose and effective mAs (milliampere seconds), even after adjusting for patient size. When sorted by size-adjusted dose, patients in the highest versus the lowest decile in size-adjusted DLP received 6.4 times the average dose (1680 vs 265 mGy-cm) even though diameter was no different (312 vs 309 mm). Effective mAs was 2.1-fold higher, unadjusted CTDIvol 2.9-fold, and phase 2.5-fold for patients in the highest versus lowest size-adjusted DLP decile. There was virtually no change in kV (kilovolt). Automatic exposure control was widely used to modulate mAs, whereas kV modulation was rare. Phase was the strongest driver of between-protocols variation. Broad adoption of optimized protocols could result in total population dose reductions of 18.6-40%. CONCLUSION: There are large variations in radiation doses for routine abdomen CT unrelated to patient size. Modification of kV and single-phase scanning could result in substantial dose reduction. CLINICAL RELEVANCE: Radiation dose-optimization techniques for routine abdomen CT are routinely under-utilized leading to higher doses than needed. Greater modification of technical parameters and number of phases could result in substantial reduction in radiation exposure to patients. KEY POINTS: • Based on an analysis of 748,846 routine abdomen CT scans in adults, radiation doses varied tremendously across patients of the same size and optimization techniques were routinely under-utilized. • The difference in observed dose was due to variation in technical parameters and phase count. Automatic exposure control was commonly used to modify effective mAs, whereas kV was rarely adjusted for patient size. Routine abdomen CT should be performed using a single phase, yet multi-phase was common. • kV modulation by patient size and restriction to a single phase for routine abdomen indications could result in substantial reduction in radiation doses using well-established dose optimization approaches.


Assuntos
Exposição à Radiação , Tomografia Computadorizada por Raios X , Adulto , Humanos , Doses de Radiação , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Abdome
2.
Mil Med ; 188(9-10): e2909-e2915, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-36394286

RESUMO

INTRODUCTION: Teleophthalmology has a natural role in the military due to the inherent organization of its medical system, which provides care to patients in remote locations around the world. Improving access to ophthalmic care enhances force readiness because ocular trauma and disease can cause vision impairment or blindness and can occur anywhere service members are located. Recently, a secure, Health Insurance Portability and Accountability Act-compliant mobile phone application (app) for teleophthalmology called Forward Operating Base Expert Telemedicine Resource Utilizing Mobile Application for Trauma (FOXTROT) was beta tested in Afghanistan and demonstrated that this solution can improve and extend ophthalmic care in a deployed environment. There are few civilian or military teleophthalmology solutions for ocular trauma and disease in an urgent or emergent ophthalmic care setting. Civilian teleophthalmology solutions have largely been developed for disease-specific models of care. In this work, we address this gap by testing the FOXTROT app in a non-deployed, emergent care setting. MATERIALS AND METHODS: We evaluated the use of the teleophthalmology mobile phone app (FOXTROT) in a non-deployed military setting at the Malcolm Grow Medical Clinics and Surgery Center at Joint Base Andrews in Maryland. Consults from the emergent care center were placed by providers using the app, and the on-call ophthalmologist responded with treatment and management recommendations. The primary outcomes were response within the requested time, visual acuity tested in both eyes, agreement between the teleophthalmology and the final diagnosis, and the number of communication or technical errors that prevented the completion of consults. The secondary outcomes were average response time and the number of consults uploaded to the medical record. RESULTS: From October 2020 to January 2022, 109 consults were received. Ten consults had communication or technical errors that prevented the completion of consults within the app and were excluded from the analysis of completed consults. Of the 99 completed consults, responses were given within the requested time in 95 (96.0%), with the average response time in 11 minutes 48 seconds (95% confidence interval, 8 minutes 57 seconds to 14 minutes 41 seconds). Visual acuity was tested in both eyes in 56 (56.6%). There was agreement between the teleophthalmology diagnosis and the final diagnosisin 40 of 50 (80.0%) consults with both a teleophthalmology and final diagnosis. Ninety-eight (99.0%) consults were uploaded to the patient's medical record. CONCLUSIONS: Beta testing of a teleophthalmology mobile phone app (FOXTROT) in a noncombat emergent care setting demonstrated that this solution can extend ophthalmic care in this environment at a military treatment facility. However, improvements in the reliability of the platform are needed in future developments to reduce communication and technical errors.


Assuntos
Traumatismos Oculares , Militares , Aplicativos Móveis , Oftalmologia , Telemedicina , Humanos , Reprodutibilidade dos Testes
3.
Int J Surg Pathol ; 31(4): 419-426, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35651303

RESUMO

Hemangioblastoma, one of the characteristic tumors associated with Von Hippel-Lindau (VHL) disease, most often presents in the central nervous system (CNS) but can uncommonly arise in extraneuraxial, or previously referred to as peripheral, locations. Without the clinical context of known VHL disease, hemangioblastoma may not enter the differential for a soft tissue mass outside the CNS. Here, we present two patients with diagnostically challenging extraneuraxial hemangioblastoma to highlight the importance of considering this entity within the differential diagnosis of soft tissue neoplasms containing clear cells and delicate vasculature. We review the relevant diagnostic features, including a suggested immunohistochemical panel, along with the potential associated clinical implications of making this diagnosis. It is recommended that affected patients be offered genetic counseling to assess for underlying VHL disease.


Assuntos
Hemangioblastoma , Neoplasias de Tecidos Moles , Doença de von Hippel-Lindau , Humanos , Hemangioblastoma/diagnóstico , Hemangioblastoma/patologia , Doença de von Hippel-Lindau/complicações , Doença de von Hippel-Lindau/diagnóstico , Doença de von Hippel-Lindau/genética , Neoplasias de Tecidos Moles/diagnóstico
4.
Radiology ; 302(2): 380-389, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34751618

RESUMO

Background Lack of standardization in CT protocol choice contributes to radiation dose variation. Purpose To create a framework to assess radiation doses within broad CT categories defined according to body region and clinical imaging indication and to cluster indications according to the dose required for sufficient image quality. Materials and Methods This was a retrospective study using Digital Imaging and Communications in Medicine metadata. CT examinations in adults from January 1, 2016 to December 31, 2019 from the University of California San Francisco International CT Dose Registry were grouped into 19 categories according to body region and required radiation dose levels. Five body regions had a single dose range (ie, extremities, neck, thoracolumbar spine, combined chest and abdomen, and combined thoracolumbar spine). Five additional regions were subdivided according to dose. Head, chest, cardiac, and abdomen each had low, routine, and high dose categories; combined head and neck had routine and high dose categories. For each category, the median and 75th percentile (ie, diagnostic reference level [DRL]) were determined for dose-length product, and the variation in dose within categories versus across categories was calculated and compared using an analysis of variance. Relative median and DRL (95% CI) doses comparing high dose versus low dose categories were calculated. Results Among 4.5 million examinations, the median and DRL doses varied approximately 10 times between categories compared with between indications within categories. For head, chest, abdomen, and cardiac (3 266 546 examinations [72%]), the relative median doses were higher in examinations assigned to the high dose categories than in examinations assigned to the low dose categories, suggesting the assignment of indications to the broad categories is valid (head, 3.4-fold higher [95% CI: 3.4, 3.5]; chest, 9.6 [95% CI: 9.3, 10.0]; abdomen, 2.4 [95% CI: 2.4, 2.5]; and cardiac, 18.1 [95% CI: 17.7, 18.6]). Results were similar for DRL doses (all P < .001). Conclusion Broad categories based on image quality requirements are a suitable framework for simplifying radiation dose assessment, according to expected variation between and within categories. © RSNA, 2021 See also the editorial by Mahesh in this issue.


Assuntos
Doses de Radiação , Tomografia Computadorizada por Raios X , Adulto , Idoso , Feminino , Humanos , Masculino , Metadados , Pessoa de Meia-Idade , Estudos Retrospectivos
5.
J Neurosurg Case Lessons ; 2(10): CASE21361, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-35855183

RESUMO

BACKGROUND: Juvenile psammomatoid ossifying fibroma (JPOF) is an uncommon benign fibro-osseous lesion that only rarely presents in the calvaria. OBSERVATIONS: The authors reported a case of JPOF in the left parietal bone of a 20-year-old patient and reviewed the 27 other cases of JPOF occurring in the calvaria as reported in the literature. LESSONS: JPOF rarely presents in the calvaria, and because diagnosis is a histopathologic one, clinicians should consider this entity when presented with a lytic, expansile mass on imaging. Little is known about the molecular mechanisms driving development of JPOF. MDM2 amplification may play a role, although this was not seen in the case presented herein.

6.
JAMA Intern Med ; 180(5): 666-675, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32227142

RESUMO

Importance: Computed tomography (CT) radiation doses vary across institutions and are often higher than needed. Objective: To assess the effectiveness of 2 interventions to reduce radiation doses in patients undergoing CT. Design, Setting, and Participants: This randomized clinical trial included 864 080 adults older than 18 years who underwent CT of the abdomen, chest, combined abdomen and chest, or head at 100 facilities in 6 countries from November 1, 2015, to September 21, 2017. Data analysis was performed from October 4, 2017, to December 14, 2018. Interventions: Imaging facilities received audit feedback alone comparing radiation-dose metrics with those of other facilities followed by the multicomponent intervention, including audit feedback with targeted suggestions, a 7-week quality improvement collaborative, and best-practice sharing. Facilities were randomly allocated to the time crossing from usual care to the intervention. Main Outcomes and Measures: Primary outcomes were the proportion of high-dose CT scans and mean effective dose at the facility level. Secondary outcomes were organ doses. Outcomes after interventions were compared with those before interventions using hierarchical generalized linear models adjusting for temporal trends and patient characteristics. Results: Across 100 facilities, 864 080 adults underwent 1 156 657 CT scans. The multicomponent intervention significantly reduced proportions of high-dose CT scans, measured using effective dose. Absolute changes in proportions of high-dose scans were 1.1% to 7.9%, with percentage reductions in the proportion of high-dose scans of 4% to 30% (abdomen: odds ratio [OR], 0.82; 95% CI, 0.77-0.88; P < .001; chest: OR, 0.92; 95% CI, 0.86-0.99; P = .03; combined abdomen and chest: OR, 0.49; 95% CI, 0.41-0.59; P < .001; and head: OR, 0.71; 95% CI, 0.66-0.76; P < .001). Reductions in the proportions of high-dose scans were greater when measured using organ doses. The absolute reduction in the proportion of high-dose scans was 6.0% to 17.2%, reflecting 23% to 58% reductions in the proportions of high-dose scans across anatomical areas. Mean effective doses were significantly reduced after multicomponent intervention for abdomen (6% reduction, P < .001), chest (4%, P < .001), and chest and abdomen (14%, P < .001) CT scans. Larger reductions in mean organ doses were 8% to 43% across anatomical areas. Audit feedback alone reduced the proportions of high-dose scans and mean dose, but reductions in observed dose were smaller. Radiologist's satisfaction with CT image quality was unchanged and high during all periods. Conclusions and Relevance: For imaging facilities, detailed feedback on CT radiation dose combined with actionable suggestions and quality improvement education significantly reduced doses, particularly organ doses. Effects of audit feedback alone were modest. Trial Registration: ClinicalTrials.gov Identifier: NCT03000751.


Assuntos
Abdome/diagnóstico por imagem , Doses de Radiação , Tórax/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Cabeça , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
BMJ ; 364: k4931, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30602590

RESUMO

OBJECTIVE: To determine patient, institution, and machine characteristics that contribute to variation in radiation doses used for computed tomography (CT). DESIGN: Prospective cohort study. SETTING: Data were assembled and analyzed from the University of California San Francisco CT International Dose Registry. PARTICIPANTS: Standardized data from over 2.0 million CT examinations of adults who underwent CT between November 2015 and August 2017 from 151 institutions, across seven countries (Switzerland, Netherlands, Germany, United Kingdom, United States, Israel, and Japan). MAIN OUTCOME MEASURES: Mean effective doses and proportions of high dose examinations for abdomen, chest, combined chest and abdomen, and head CT were determined by patient characteristics (sex, age, and size), type of institution (trauma center, care provision 24 hours per day and seven days per week, academic, private), institutional practice volume, machine factors (manufacturer, model), country, and how scanners were used, before and after adjustment for patient characteristics, using hierarchical linear and logistic regression. High dose examinations were defined as CT scans with doses above the 75th percentile defined during a baseline period. RESULTS: The mean effective dose and proportion of high dose examinations varied substantially across institutions. The doses varied modestly (10-30%) by type of institution and machine characteristics after adjusting for patient characteristics. By contrast, even after adjusting for patient characteristics, wide variations in radiation doses across countries persisted, with a fourfold range in mean effective dose for abdomen CT examinations (7.0-25.7 mSv) and a 17-fold range in proportion of high dose examinations (4-69%). Similar variation across countries was observed for chest (mean effective dose 1.7-6.4 mSv, proportion of high dose examinations 1-26%) and combined chest and abdomen CT (10.0-37.9 mSv, 2-78%). Doses for head CT varied less (1.4-1.9 mSv, 8-27%). In multivariable models, the dose variation across countries was primarily attributable to institutional decisions regarding technical parameters (that is, how the scanners were used). CONCLUSIONS: CT protocols and radiation doses vary greatly across countries and are primarily attributable to local choices regarding technical parameters, rather than patient, institution, or machine characteristics. These findings suggest that the optimization of doses to a consistent standard should be possible. STUDY REGISTRATION: Clinicaltrials.gov NCT03000751.


Assuntos
Doses de Radiação , Tomografia Computadorizada por Raios X/normas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta à Radiação , Feminino , Saúde Global , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de Registros , Tomografia Computadorizada por Raios X/efeitos adversos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Adulto Jovem
8.
Breast Cancer Res Treat ; 129(2): 607-16, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21597921

RESUMO

Breast cancer has a long natural history. Established and emerging biologic markers address overall risk but not necessarily timing of recurrence. 346 adjuvant naïve breast cancer cases from Guy's Hospital with 23 years minimum follow-up and archival blocks were recut and reassessed for hormone-receptors (HR), HER2-receptor and grade. Disease-specific survival (DSS) was analyzed by recursive partitioning. To validate insights from this analysis, gene-signatures (proliferative and HR-negative) were evaluated for their ability to predict early versus late metastatic risk in 683 node-negative, adjuvant naïve breast cancers annotated with expression microarray data. Risk partitioning showed that adjuvant naïve node-negative outcome risk was primarily partitioned by tumor receptor status and grade but not tumor size. HR-positive and HER2-negative (HRpos) risk was partitioned by tumor grade; low grade cases have very low early risk but a 20% fall-off in DSS 10 or more years after diagnosis. Higher grade HRpos cases have risk over >20 years. Triple-negative (Tneg) and HER2-positive (HER2pos) cases DSS events occurred primarily within the first 5 years. Among node-positive cases, only low grade conferred late risk, suggesting that proliferative gene signatures that identify proliferation would be important for predicting early but not late recurrence. Using pooled data from four publicly available data sets for node-negative tumors annotated with gene expression and outcome data, we evaluated four prognostic gene signatures: two proliferation-based and two immune function-based. Tumor proliferative capacity predicted early but not late metastatic risk for HRpos cases. The immune function or HRneg specific signatures predicted only early metastatic risk in Tneg and HER2pos cases. Breast cancer prognostic signatures need to inform both risk and timing of metastatic events and may best be applied within subsets. Current signatures predict for outcome risk within 5 years of diagnosis. Predictors of late risk for HR positive disease are needed.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/terapia , Recidiva Local de Neoplasia , Adulto , Idoso , Neoplasias da Mama/química , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Neoplasias da Mama/secundário , Proliferação de Células , Intervalo Livre de Doença , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Londres , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Modelos de Riscos Proporcionais , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
9.
Compr Psychiatry ; 50(5): 471-6, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19683618

RESUMO

OBJECTIVE: The objective of the study was to determine the reliability and validity of a Chinese version of the Mood Disorder Questionnaire (MDQ) in the general population in Hong Kong. METHODS: One thousand five hundred eighteen adults aged at least 18 years were randomly drawn from the general population and interviewed using a lay-administered version of the MDQ. A subsample of 114 randomly selected participants received a telephone-based Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorder, Fourth Edition. Six subjects were diagnosed to have bipolar disorder (bipolar I = 1, bipolar II = 4, and bipolar not otherwise specified = 1), 13 had substance/alcohol use disorder, and 95 had neither bipolar nor substance/alcohol use disorder. We determined the internal consistency, factor structure, and concurrent validity of the Chinese MDQ. RESULTS: The Cronbach alpha coefficient of the Chinese MDQ was 0.78. Principal component analysis with varimax rotation indicated a "euphoria-irritability-racing thoughts" factor, an "energized-activity" factor, and a "risky behavior" factor, which explained 46.6% of the rotated variance. There were significant differences in MDQ scores between the bipolar and non-bipolar non-substance/alcohol use disorder groups. The performance of the Chinese MDQ for detecting bipolar disorder was limited by a low sensitivity. Using the original cutoff criterion, defined as clustering of 7 or more symptoms that caused moderate or severe problems, the sensitivity was 0%, whereas the overall specificity was 95.4%. Lowering the cutoff criterion to a symptom score of at least 7 that caused minor or more problems yielded the best sensitivity (0.50) and specificity (0.92). CONCLUSION: The Chinese MDQ is a reliable and valid measure of bipolar disorder in the community.


Assuntos
Transtorno Bipolar/diagnóstico , Transtorno Bipolar/etnologia , Comparação Transcultural , Manual Diagnóstico e Estatístico de Transtornos Mentais , Idioma , Determinação da Personalidade/estatística & dados numéricos , Adulto , Alcoolismo/diagnóstico , Alcoolismo/etnologia , Alcoolismo/psicologia , Transtorno Bipolar/psicologia , Comorbidade , Feminino , Hong Kong , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria/estatística & dados numéricos , Reprodutibilidade dos Testes , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/etnologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Tradução , Adulto Jovem
10.
J Craniofac Surg ; 16(1): 3-5, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15699636

RESUMO

The aim of the study was to elucidate the precise anatomical detail of the submental perforating artery (SPA) and avoid bleeding during the facelift operation or submental procedures. Latex-injected heads of eight fresh Korean cadavers (6 male, 2 female) were used. After the facial artery was found, the dissection was continued anteriorly, following the submental artery (SMA). When the SMA ran anteriorly about 15.5 mm (15.5 +/- 2.2 mm) from the facial artery and reached about halfway from the gonion to the menton, it gave off one or two perforating branches (SPA, mean number 1.6). The SPA ran upward and forward until it reached the skin. Diameter of the SPA at its beginning was 1.25 +/- 0.36 mm. The point of emergence of the SPA from the SMA was about halfway (49% +/- 14%) from the gonion to the menton, about 6 mm (6.1 +/- 1.9 mm) inferior to the lower border of mandible. The high risk of injuring the vessels during the facelift can be explained by the close vicinity of the SPA to the mandibular inferior border.


Assuntos
Queixo/irrigação sanguínea , Músculos Faciais/irrigação sanguínea , Idoso , Artérias/anatomia & histologia , Perda Sanguínea Cirúrgica/prevenção & controle , Cadáver , Dissecação , Feminino , Humanos , Masculino , Mandíbula/irrigação sanguínea , Pessoa de Meia-Idade , Ritidoplastia/efeitos adversos , Pele/irrigação sanguínea
11.
J Craniofac Surg ; 13(5): 721-3, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12218805

RESUMO

All masks are created by craftspeople. Accordingly, most masks are generally predictable in dimensions, and the portraitures usually depict the faces and heads of humans. The authors found some masks representing the features of craniofacial anomalies, such as hemifacial microsomia and, rarely, cleft lip. Reviewing the legends of wearing masks with a medley of grotesque features, the authors could deduce the tone of society in those days. A mask, "crooked mouth," of Native Americans shows typical lineament of hemifacial microsomia. The deformity of the face was legendarily regarded as resulting from trauma caused by either "one's fault" or a "curse of God." "Yangban" (noblemen of aristocratic class) customarily wore the cleft lip mask in age-old Korean masquerade revels. Laymen ridiculed Yangban by making cleft lip masks for them. The authors presume that the victims of craniofacial deformities were treated contemptuously at that time.


Assuntos
Fenda Labial/história , Etnicidade/história , Assimetria Facial/história , Máscaras/história , Medicina nas Artes , História do Século XVIII , História do Século XIX , Humanos , Indígenas Norte-Americanos/história , Coreia (Geográfico) , México , Estados Unidos
12.
J Craniofac Surg ; 13(2): 202-4, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12000873

RESUMO

Our exploration disclosed 17 (40%) stranded muscles of 42 hemifacial specimens of Korean cadavers. We name this distinct muscle "Orbitozygomatic Muscle (OZM)" that is either an aberrant orbicularis oculi muscle or a separate muscle. A triangular space bounded superiorly by the lowest edge of the orbicularis oculi muscle (OOM), laterally by Zygomaticus Minor, and inferiorly by OMZ gives way to neurovascular bundle and suborbicularis oculi fat pad (SOOF).


Assuntos
Músculos Faciais/anatomia & histologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Órbita , Zigoma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...