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1.
Genetics ; 226(4)2024 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-38290049

RESUMO

Mutations in SETD2 are among the most prevalent drivers of renal cell carcinoma (RCC). We identified a novel single nucleotide polymorphism (SNP) in SETD2, E902Q, within a subset of RCC patients, which manifests as both an inherited or tumor-associated somatic mutation. To determine if the SNP is biologically functional, we used CRISPR-based genome editing to generate the orthologous mutation within the Drosophila melanogaster Set2 gene. In Drosophila, the homologous amino acid substitution, E741Q, reduces H3K36me3 levels comparable to Set2 knockdown, and this loss is rescued by reintroduction of a wild-type Set2 transgene. We similarly uncovered significant defects in spindle morphogenesis, consistent with the established role of SETD2 in methylating α-Tubulin during mitosis to regulate microtubule dynamics and maintain genome stability. These data indicate the Set2 E741Q SNP affects both histone methylation and spindle integrity. Moreover, this work further suggests the SETD2 E902Q SNP may hold clinical relevance.


Assuntos
Carcinoma de Células Renais , Proteínas de Drosophila , Neoplasias Renais , Animais , Humanos , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Histonas/genética , Histonas/metabolismo , Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Polimorfismo de Nucleotídeo Único , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Fuso Acromático/genética , Fuso Acromático/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo
2.
Invest Radiol ; 59(8): 569-576, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38265058

RESUMO

OBJECTIVES: The Centers for Medicare and Medicaid Services funded the development of a computed tomography (CT) quality measure for use in pay-for-performance programs, which balances automated assessments of radiation dose with image quality to incentivize dose reduction without compromising the diagnostic utility of the tests. However, no existing quantitative method for assessing CT image quality has been validated against radiologists' image quality assessments on a large number of CT examinations. Thus to develop an automated measure of image quality, we tested the relationship between radiologists' subjective ratings of image quality with measurements of radiation dose and image noise. MATERIALS AND METHODS: Board-certified, posttraining, clinically active radiologists rated the image quality of 200 diagnostic CT examinations from a set of 734, representing 14 CT categories. Examinations with significant distractions, motion, or artifact were excluded. Radiologists rated diagnostic image quality as excellent, adequate, marginally acceptable, or poor; the latter 2 were considered unacceptable for rendering diagnoses. We quantified the relationship between ratings and image noise and radiation dose, by category, by analyzing the odds of an acceptable rating per standard deviation (SD) increase in noise or geometric SD (gSD) in dose. RESULTS: One hundred twenty-five radiologists contributed 24,800 ratings. Most (89%) were acceptable. The odds of an examination being rated acceptable statistically significantly increased per gSD increase in dose and decreased per SD increase in noise for most categories, including routine dose head, chest, and abdomen-pelvis, which together comprise 60% of examinations performed in routine practice. For routine dose abdomen-pelvis, the most common category, each gSD increase in dose raised the odds of an acceptable rating (2.33; 95% confidence interval, 1.98-3.24), whereas each SD increase in noise decreased the odds (0.90; 0.79-0.99). For only 2 CT categories, high-dose head and neck/cervical spine, neither dose nor noise was associated with ratings. CONCLUSIONS: Radiation dose and image noise correlate with radiologists' image quality assessments for most CT categories, making them suitable as automated metrics in quality programs incentivizing reduction of excessive radiation doses.


Assuntos
Doses de Radiação , Tomografia Computadorizada por Raios X , Humanos , Tomografia Computadorizada por Raios X/métodos , Radiologistas , Estados Unidos , Melhoria de Qualidade
3.
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
4.
Eur Radiol ; 34(4): 2416-2425, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37798408

RESUMO

OBJECTIVES: The most accurate method for estimating patient effective dose (a principal metric for tracking patient radiation exposure) from computed tomography (CT) requires time-intensive Monte Carlo simulation. A simpler method multiplies a scalar coefficient by the widely available scanner-reported dose length product (DLP) to estimate effective dose. We developed new adult effective dose coefficients using actual patient scans and assessed their agreement with Monte Carlo simulation. METHODS: A multicenter sample of 216,906 adult CT scans was prospectively assembled in 2015-2020 from the University of California San Francisco International CT Dose Registry and the University of Florida library of computational phantoms. We generated effective dose coefficients for eight body regions, stratified by patient sex, diameter, and scanner manufacturer. We applied the new coefficients to DLPs to calculate effective doses and assess their correlations with Monte Carlo radiation transport-generated effective dose. RESULTS: Effective dose coefficients varied by body region and decreased in magnitude with increasing patient diameter. Coefficients were approximately twofold higher for torso scans in smallest compared with largest diameter categories. For example, abdomen and pelvis coefficients decreased from 0.027 to 0.013 mSv/mGy-cm between the 16-20 cm and 41+ cm categories. There were modest but consistent differences by sex and manufacturer. Diameter-based coefficients used to estimate effective dose produced strong correlations with the reference standard (Pearson correlations 0.77-0.86). The reported conversion coefficients differ from previous studies, particularly in neck CT. CONCLUSIONS: New effective dose coefficients derived from empirical clinical scans can be used to easily estimate effective dose using scanner-reported DLP. CLINICAL RELEVANCE STATEMENT: Scalar coefficients multiplied by DLP offer a simple approximation to effective dose, a key radiation dose metric. New effective dose coefficients from this study strongly correlate with gold standard, Monte Carlo-generated effective dose, and differ somewhat from previous studies. KEY POINTS: • Previous effective dose coefficients were derived from theoretical models rather than real patient data. • The new coefficients (from a large registry/phantom library) differ from previous studies. • The new coefficients offer reasonably reliable values for estimating effective dose.


Assuntos
Modelos Teóricos , Radiometria , Adulto , Humanos , Simulação por Computador , Método de Monte Carlo , Imagens de Fantasmas , Doses de Radiação , Radiometria/métodos , Tomografia Computadorizada por Raios X/métodos , Masculino , Feminino
5.
Eur Radiol ; 34(3): 1605-1613, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37646805

RESUMO

OBJECTIVE: Quantify the relationship between CT acquisition parameters and radiation dose, how often parameters are adjusted in real-world practice, and their degree of contribution to real-world dose distribution. Identify discrepancies between parameters that are impactful in theory and impactful in practice. METHODS: This study analyses 1.3 million consecutive adult routine abdomen exams performed between November 2015 and Jan 2021 included in the University of California, San Francisco International CT Dose Registry of 155 institutions. We calculated geometric standard deviation (gSD) for five parameters (kV, mAs, spiral pitch, number of phases, scan length) to assess variation in practice. A Gaussian mixed regression model was performed to predict the radiation dose-length product (DLP) using the parameters. Three conceptualizations of "impact" were computed for each parameter. To reflect the theoretical impact, we predict the increase in DLP per 10% (and 15%) increase in the parameter. To reflect the real-world practical impact, we predict the increase in DLP per gSD increase in the parameter. RESULTS: Among studied examinations, mAs, number of phases, and scan length were frequently manipulated (gSD 1.52-1.70); kV was rarely manipulated (gSD 1.07). Theoretically, kV is the most impactful parameter (29% increase in DLP per 10% increase in kV, versus 5-9% increase for other parameters). In real-world practice, kV is less impactful; for each gSD increase in kV, the DLP increases by 20%, versus 22-69% for other parameters. CONCLUSION: Despite the potential impact of kV on radiation dose, this parameter is rarely manipulated in common practice and this potential remains untapped. CLINICAL RELEVANCE STATEMENT: CT beam energy (kV) modulation has the potential to strongly reduce radiation over-dosage to the patient, theoretically more so than similar degrees of modulation in other CT acquisition parameters. Despite this, beam energy modulation rarely occurs in practice, leaving its potential untapped. KEY POINTS: • The relationship between CT acquisition parameter selection and radiation dose roughly coincided with established theoretical understanding. • CT acquisition parameters differ from each other in frequency and magnitude of manipulation, with beam energy (kV) being rarely manipulated. • Beam energy (kV) has the potential to substantially impact radiation dose, but because it is rarely manipulated, it is the least impactful CT acquisition parameter affecting radiation dose in practice.


Assuntos
Tomografia Computadorizada por Raios X , Adulto , Humanos , Doses de Radiação
7.
Pulm Circ ; 13(3): e12282, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37614831

RESUMO

Pediatric patients with pulmonary hypertension (PH) receive imaging studies that use ionizing radiation (radiation) such as computed tomography (CT) and cardiac catheterization to guide clinical care. Radiation exposure is associated with increased cancer risk. It is unknown how much radiation pediatric PH patients receive. The objective of this study is to quantify radiation received from imaging and compute associated lifetime cancer risks for pediatric patients with PH. Electronic health records between 2012 and 2022 were reviewed and radiation dose data were extracted. Organ doses were estimated using Monte Carlo modeling. Cancer risks for each patient were calculated from accumulated exposures using National Cancer Institute tools. Two hundred and forty-nine patients with PH comprised the study cohort; 97% of patients had pulmonary arterial hypertension, PH due to left heart disease, or PH due to chronic lung disease. Mean age at the time of the first imaging study was 2.5 years (standard deviation [SD] = 4.9 years). Patients underwent a mean of 12 studies per patient per year, SD = 32. Most (90%) exams were done in children <5 years of age. Radiation from CT and cardiac catheterization accounted for 88% of the total radiation dose received. Cumulative mean effective dose was 19 mSv per patient (SD = 30). Radiation dose exposure resulted in a mean increased estimated lifetime cancer risk of 7.6% (90% uncertainty interval 3.0%-14.2%) in females and 2.8% (1.2%-5.3%) in males. Careful consideration for the need of radiation-based imaging studies is warranted, especially in the youngest of children.

8.
Pharmaceutics ; 15(4)2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37111759

RESUMO

Chordomas account for approximately 1-4% of all malignant bone tumors and 20% of primary tumors of the spinal column. It is a rare disease, with an incidence estimated to be approximately 1 per 1,000,000 people. The underlying causative mechanism of chordoma is unknown, which makes it challenging to treat. Chordomas have been linked to the T-box transcription factor T (TBXT) gene located on chromosome 6. The TBXT gene encodes a protein transcription factor TBXT, or brachyury homolog. Currently, there is no approved targeted therapy for chordoma. Here, we performed a small molecule screening to identify small chemical molecules and therapeutic targets for treating chordoma. We screened 3730 unique compounds and selected 50 potential hits. The top three hits were Ribociclib, Ingenol-3-angelate, and Duvelisib. Among the top 10 hits, we found a novel class of small molecules, including proteasomal inhibitors, as promising molecules that reduce the proliferation of human chordoma cells. Furthermore, we discovered that proteasomal subunits PSMB5 and PSMB8 are increased in human chordoma cell lines U-CH1 and U-CH2, confirming that the proteasome may serve as a molecular target whose specific inhibition may lead to better therapeutic strategies for chordoma.

9.
BMC Med Res Methodol ; 23(1): 90, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-37041459

RESUMO

Indirect standardization, and its associated parameter the standardized incidence ratio, is a commonly-used tool in hospital profiling for comparing the incidence of negative outcomes between an index hospital and a larger population of reference hospitals, while adjusting for confounding covariates. In statistical inference of the standardized incidence ratio, traditional methods often assume the covariate distribution of the index hospital to be known. This assumption severely compromises one's ability to compute required sample sizes for high-powered indirect standardization, as in contexts where sample size calculation is desired, there are usually no means of knowing this distribution. This paper presents novel statistical methodology to perform sample size calculation for the standardized incidence ratio without knowing the covariate distribution of the index hospital and without collecting information from the index hospital to estimate this covariate distribution. We apply our methods to simulation studies and to real hospitals, to assess both its capabilities in a vacuum and in comparison to traditional assumptions of indirect standardization.


Assuntos
Hospitais , Humanos , Tamanho da Amostra , Simulação por Computador , Padrões de Referência
10.
Pediatr Radiol ; 53(8): 1659-1668, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36922419

RESUMO

BACKGROUND: The most accurate method for estimating effective dose (the most widely understood metric for tracking patient radiation exposure) from computed tomography (CT) requires time-intensive Monte Carlo simulation. A simpler method multiplies a scalar coefficient by the widely available scanner-reported dose length product (DLP) to estimate effective dose. OBJECTIVE: Develop pediatric effective dose coefficients and assess their agreement with Monte Carlo simulation. MATERIALS AND METHODS: Multicenter, population-based sample of 128,397 pediatric diagnostic CT scans prospectively assembled in 2015-2020 from the University of California San Francisco International CT Dose Registry and the University of Florida library of highly realistic hybrid computational phantoms. We generated effective dose coefficients for seven body regions, stratified by patient age, diameter, and scanner manufacturer. We applied the new coefficients to DLPs to calculate effective doses and assessed their correlations with Monte Carlo radiation transport-generated effective doses. RESULTS: The reported effective dose coefficients, generally higher than previous studies, varied by body region and decreased in magnitude with increasing age. Coefficients were approximately 4 to 13-fold higher (across body regions) for patients <1 year old compared with patients 15-21 years old. For example, head CT (54% of scans) dose coefficients decreased from 0.039 to 0.003 mSv/mGy-cm in patients <1 year old vs. 15-21 years old. There were minimal differences by manufacturer. Using age-based conversion coefficients to estimate effective dose produced moderate to strong correlations with Monte Carlo results (Pearson correlations 0.52-0.80 across body regions). CONCLUSIONS: New pediatric effective dose coefficients update existing literature and can be used to easily estimate effective dose using scanner-reported DLP.


Assuntos
Radiometria , Tomografia Computadorizada por Raios X , Lactente , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Doses de Radiação , Radiometria/métodos , Tomografia Computadorizada por Raios X/métodos , Simulação por Computador , Imagens de Fantasmas , Método de Monte Carlo
12.
Front Immunol ; 13: 899975, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35757726

RESUMO

Regulatory T cells (Tregs) have shown great promise as a means of cellular therapy in a multitude of allo- and auto-immune diseases-due in part to their immunosuppressive potency. Nevertheless, the clinical efficacy of human Tregs in patients has been limited by their poor in vivo homeostasis. To avert apoptosis, Tregs require stable antigenic (CD3ζ/T-cell-receptor-mediated), co-stimulatory (CD28-driven), and cytokine (IL-2-dependent) signaling. Notably, this sequence of signals supports an activated Treg phenotype that includes a high expression of granzymes, particularly granzyme B (GrB). Previously, we have shown that aside from the functional effects of GrB in lysing target cells to modulate allo-immunity, GrB can leak out of the intracellular lysosomal granules of host Tregs, initiating pro-apoptotic pathways. Here, we assessed the role of inhibiting mechanistic target of rapamycin complex 1 (mTORC1), a recently favored drug target in the transplant field, in regulating human Treg apoptosis via GrB. Using ex vivo models of human Treg culture and a humanized mouse model of human skin allotransplantation, we found that by inhibiting mTORC1 using rapamycin, intracytoplasmic expression and functionality of GrB diminished in host Tregs; lowering human Treg apoptosis by in part decreasing the phosphorylation of S6K and c-Jun. These findings support the already clinically validated effects of mTORC1 inhibition in patients, most notably their stabilization of Treg bioactivity and in vivo homeostasis.


Assuntos
Apoptose , Linfócitos T Reguladores , Animais , Granzimas/metabolismo , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Receptores de Antígenos de Linfócitos T/metabolismo
13.
J Am Coll Radiol ; 19(4): 534-541, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35227651

RESUMO

BACKGROUND: Advances in CT have facilitated widespread use of medical imaging while increasing patient lifetime exposure to ionizing radiation. PURPOSE: To describe dose optimization strategies used by health care organizations to optimize radiation dose and image quality. MATERIALS AND METHODS: A qualitative study of semistructured interviews conducted with 26 leaders from 19 health care systems in the United States, Europe, and Japan. Interviews focused on strategies that were used to optimize radiation dose at the organizational level. A directed content analysis approach was used in data analysis. RESULTS: Analysis identified seven organizational strategies used by these leaders for optimizing CT dose: (1) engaging radiologists and technologists, (2) establishing a CT dose committee, (3) managing organizational change, (4) providing leadership and support, (5) monitoring and benchmarking, (6) modifying CT protocols, and (7) changes in equipment and work rules. CONCLUSIONS: Leaders in these health systems engaged in specific strategies to optimize CT dose within their organizations. The strategies address challenges health systems encounter in optimizing CT dose at the organizational level and offer an evolving framework for consideration in dose optimization efforts for enhancing safety and use of medical imaging.


Assuntos
Atenção à Saúde , Liderança , Diagnóstico por Imagem , Europa (Continente) , Humanos , Inovação Organizacional , Estados Unidos
14.
Otol Neurotol ; 43(4): e408-e413, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35239618

RESUMO

INTRODUCTION: Intra-operative electrophysiological testing is being increasingly used to determine device functionality. Impedance abnormalities (open or short circuits) measured at time of surgery pose a dilemma: is it likely to resolve or is it a permanent fault? There is little in the literature on how to manage these intraoperative finding and if, at time of surgery, the back-up device should be used. METHODS: We routinely undertake impedance testing twice intraoperatively, as well as at switch on, 1 and 3 months postoperatively. Retrospective impedance thresholds were analysed for one surgeon's cases between January 2018 and December 2019. RESULTS: There were 235 cochlear implants performed for 217 patients (5,020 electrode contacts) analysed. Thirty-three electrodes had abnormal impedance thresholds on first intraoperative cycle of testing, 76% resolving with the second testing cycle electrode contacts that demonstrated abnormal impedance during both intraoperative test cycles were 16.54 times (95%CI 2.55-107.13, p = 0.003) more likely to be abnormal at three months. Fifty percent resolved by switch on. The intraoperative abnormalities made up 26% of electrode abnormalities seen at 3 months postoperatively. DISCUSSION: This study demonstrates the utility of 2 cycles of intraoperative impedance testing, with persistently abnormal electrodes having 16 times the likelihood of persistent abnormalities of impedance, and 50% resolution. These persistent intra-operative abnormal electrodes are responsibly for 26% of electrode abnormalities at 3 months. This information is useful for the surgeon when considering use of the backup cochlear implant device.


Assuntos
Implante Coclear , Implantes Cocleares , Cóclea/cirurgia , Impedância Elétrica , Humanos , Estudos Retrospectivos
15.
Pediatr Radiol ; 52(3): 445-452, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34866159

RESUMO

BACKGROUND: Radiation dose metrics vary by the calibration reference phantom used to report doses. By convention, 16-cm diameter cylindrical polymethyl-methacyrlate phantoms are used for head imaging and 32-cm diameter phantoms are used for body imaging in adults. Actual usage patterns in children remain under-documented. OBJECTIVE: This study uses the University of California San Francisco International CT Dose Registry to describe phantom selection in children by patient age, body region and scanner manufacturer, and the consequent impact on radiation doses. MATERIALS AND METHODS: For 106,837 pediatric computed tomography (CT) exams collected between Jan. 1, 2015, and Nov. 2, 2020, in children up to 17 years of age from 118 hospitals and imaging facilities, we describe reference phantom use patterns by body region, age and manufacturer, and median and 75th-percentile dose-length product (DLP) and volume CT dose index (CTDIvol) doses when using 16-cm vs. 32-cm phantoms. RESULTS: There was relatively consistent phantom selection by body region. Overall, 98.0% of brain and skull examinations referenced 16-cm phantoms, and 95.7% of chest, 94.4% of abdomen and 100% of cervical-spine examinations referenced 32-cm phantoms. Only GE deviated from this practice, reporting chest and abdomen scans using 16-cm phantoms with some frequency in children up to 10 years of age. DLP and CTDIvol values from 16-cm phantom-referenced scans were 2-3 times higher than 32-cm phantom-referenced scans. CONCLUSION: REFERENCE PHANTOM SELECTION IS HIGHLY CONSISTENT, WITH A SMALL BUT SIGNIFICANT NUMBER OF ABDOMEN AND CHEST SCANS (~5%) USING 16-CM PHANTOMS IN YOUNGER CHILDREN, WHICH PRODUCES DLP VALUES APPROXIMATELY TWICE AS HIGH AS EXAMS REFERENCED TO 32-CM PHANTOMS.


Assuntos
Tórax , Tomografia Computadorizada por Raios X , Adulto , Criança , Humanos , Imagens de Fantasmas , Doses de Radiação , Sistema de Registros , Tomografia Computadorizada por Raios X/métodos
16.
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
17.
Eur Radiol ; 32(3): 1971-1982, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34642811

RESUMO

OB JECTIVES: The European Society of Radiology identified 10 common indications for computed tomography (CT) as part of the European Study on Clinical Diagnostic Reference Levels (DRLs, EUCLID), to help standardize radiation doses. The objective of this study is to generate DRLs and median doses for these indications using data from the UCSF CT International Dose Registry. METHODS: Standardized data on 3.7 million CTs in adults were collected between 2016 and 2019 from 161 institutions across seven countries (United States of America (US), Switzerland, Netherlands, Germany, UK, Israel, Japan). DRLs (75th percentile) and median doses for volumetric CT-dose index (CTDIvol) and dose-length product (DLP) were assessed for each EUCLID category (chronic sinusitis, stroke, cervical spine trauma, coronary calcium scoring, lung cancer, pulmonary embolism, coronary CT angiography, hepatocellular carcinoma (HCC), colic/abdominal pain, appendicitis), and US radiation doses were compared with European. RESULTS: The number of CT scans within EUCLID categories ranged from 8,933 (HCC) to over 1.2 million (stroke). There was greater variation in dose between categories than within categories (p < .001), and doses were significantly different between categories within anatomic areas. DRLs and median doses were assessed for all categories. DRLs were higher in the US for 9 of the 10 indications (except chronic sinusitis) than in Europe but with a significantly higher sample size in the US. CONCLUSIONS: DRLs for CTDIvol and DLP for EUCLID clinical indications from diverse organizations were established and can contribute to dose optimization. These values were usually significantly higher in the US than in Europe. KEY POINTS: • Registry data were used to create benchmarks for 10 common indications for CT identified by the European Society of Radiology. • Observed US radiation doses were higher than European for 9 of 10 indications (except chronic sinusitis). • The presented diagnostic reference levels and median doses highlight potentially unnecessary variation in radiation dose.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Adulto , Níveis de Referência de Diagnóstico , Humanos , Doses de Radiação , Valores de Referência , Sistema de Registros , Tomografia Computadorizada por Raios X
19.
Sci Rep ; 11(1): 6014, 2021 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727573

RESUMO

New Onset Diabetes After Transplantation (NODAT) is a serious metabolic complication. While ß-cell dysfunction is considered the main contributing factor in the development of NODAT, the precise pathogenesis is not well understood. Cytokines are thought to be involved in the inflammation of islet ß-cells in diabetes; however, few studies have investigated this hypothesis in NODAT. A total of 309 kidney transplant recipients (KTRs) were included in this study. An association between kidney transplants, and the development of diabetes after transplant (NODAT) was investigated. Comparison was made between KTRs who develop diabetes (NODAT cases) or did not develop diabetes (control), using key cytokines, IL-6 G (- 174)C, macrophage mediator; IL-4 C (- 490)T, T helper (Th)-2 cytokine profile initiator; Th-1 cytokine profile initiator interferon-γ T (+ 874) A gene and TGF ß1 C (+ 869) T gene polymorphisms were investigated. The genes were amplified using well-established polymerase chain reaction (PCR) techniques in our laboratory. Compared to the AA and AT genotypes of interferon gamma (IFNG), there was a strong association between the TT genotype of IFNG and NODAT kidney transplant recipients (KTRs) versus non-NODAT KTRs (p = 0.005). The AA genotype of IFNG was found to be predominant in the control group (p = 0.004). Also, significant variations of IL6 G (- 174) C, IL-4 C (- 590) T, interferon-γ T (+ 874) A gene and transforming growth factor ß1 C (+ 869) T may contribute to NODAT. Our data is consistent with theTh-1/T-reg pathway of immunity. Further larger pan Arab studies are required to confirm our findings.


Assuntos
Citocinas/genética , Diabetes Mellitus , Transplante de Rim , Polimorfismo de Nucleotídeo Único , Adulto , Diabetes Mellitus/etiologia , Diabetes Mellitus/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
20.
Curr Allergy Asthma Rep ; 21(3): 19, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33666743

RESUMO

PURPOSE OF REVIEW: Ochronosis and alkaptonuria are manifestations of the same condition-a rare autosomal recessive disorder resulting from a constitutional lack of homogentisate 1,2-dioxygenase (HGD) with the consequent accumulation of homogentisic acid (HGA). In ochronosis, HGA undergoes autoxidation as well as enzymatic oxidation to form an ochronotic pigment that accumulates in cartilage and connective tissues. In the beginning, there is homogentisic aciduria and pigmentation of cartilages and other connective tissues. In later years, generalized osteoarthritis of the spine and large joints, termed ochronotic arthropathy, develops. RECENT FINDINGS: The diagnosis is confirmed by quantitative measurement of HGA in urine and mutation analysis of the HGD gene. One of the differential diagnoses for the skin findings is exogenous ochronosis, a limited hyperpigmentation of skin caused by some chemicals. As for the lumbar spine findings, there can be radiographic similarities with ankylosing spondylitis (AS) including reduced intervertebral disc spaces and loss of lumbar lordosis; however, ochronosis will spare the sacroiliac joint, and the lumbar spine will show dense, wafer-like disk calcification with a vacuum disc phenomenon and broad syndesmophytes. Here, we present a case of a patient with probable ochronosis that was treated many years as ankylosing spondylitis without response, and we provide a review of the current literature on ochronosis pathogenesis, diagnosis, and treatment.


Assuntos
Ocronose , Espondilite Anquilosante , Alcaptonúria/diagnóstico , Animais , Ácido Homogentísico , Humanos , Ocronose/diagnóstico , Espondilite Anquilosante/diagnóstico
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