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PURPOSE: We evaluated the prognostic value of 18F-sodium fluoride (NaF) PET/CT in patients with urological malignancies treated with cabozantinib and nivolumab with or without ipilimumab. METHODS: We prospectively recruited patients with advanced urological malignancies into a phase I trial of cabozantinib plus nivolumab with or without ipilimumab. NaF PET/CT scans were performed pre- and 8 weeks post-treatment. We measured the total volume of fluoride avid bone (FTV) using a standardized uptake value (SUV) threshold of 10. We used Kaplan-Meier analysis to predict the overall survival (OS) of patients in terms of SUVmax, FTV, total lesion fluoride (TLF) uptake at baseline and 8 weeks post-treatment, and percent change in FTV and TLF. RESULT: Of 111 patients who underwent NaF PET/CT, 30 had bone metastases at baseline. Four of the 30 patients survived for the duration of the study period. OS ranged from 0.23 to 34 months (m) (median 6.0 m). The baseline FTV of all 30 patients ranged from 9.6 to 1570 ml (median 439 ml). The FTV 8 weeks post-treatment was 56-6296 ml (median 448 ml) from 19 available patients. Patients with higher TLF at baseline had shorter OS than patients with lower TLF (3.4 vs 14 m; p = 0.022). Patients with higher SUVmax at follow-up had shorter OS than patients with lower SUVmax (5.6 vs 24 m; p = 0.010). However, FTV and TLF 8 weeks post-treatment did not show a significant difference between groups (5.6 vs 17 m; p = 0.49), and the percent changes in FTV (12 vs 14 m; p = 0.49) and TLF (5.6 vs 17 m; p = 0.54) also were not significant. CONCLUSION: Higher TLF at baseline and higher SUVmax at follow-up NaF PET/CT corresponded with shorter survival in patients with bone metastases from urological malignancies who underwent treatment. NaF PET/CT may be a useful predictor of OS in this population.
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Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias Urogenitales , Anilidas , Fluoruros , Humanos , Ipilimumab , Nivolumab/uso terapéutico , Piridinas , Fluoruro de SodioRESUMEN
Purpose To investigate whether photon-counting detector (PCD) technology can improve dose-reduced chest computed tomography (CT) image quality compared with that attained with conventional energy-integrating detector (EID) technology in vivo. Materials and Methods This was a HIPAA-compliant institutional review board-approved study, with informed consent from patients. Dose-reduced spiral unenhanced lung EID and PCD CT examinations were performed in 30 asymptomatic volunteers in accordance with manufacturer-recommended guidelines for CT lung cancer screening (120-kVp tube voltage, 20-mAs reference tube current-time product for both detectors). Quantitative analysis of images included measurement of mean attenuation, noise power spectrum (NPS), and lung nodule contrast-to-noise ratio (CNR). Images were qualitatively analyzed by three radiologists blinded to detector type. Reproducibility was assessed with the intraclass correlation coefficient (ICC). McNemar, paired t, and Wilcoxon signed-rank tests were used to compare image quality. Results Thirty study subjects were evaluated (mean age, 55.0 years ± 8.7 [standard deviation]; 14 men). Of these patients, 10 had a normal body mass index (BMI) (BMI range, 18.5-24.9 kg/m2; group 1), 10 were overweight (BMI range, 25.0-29.9 kg/m2; group 2), and 10 were obese (BMI ≥30.0 kg/m2, group 3). PCD diagnostic quality was higher than EID diagnostic quality (P = .016, P = .016, and P = .013 for readers 1, 2, and 3, respectively), with significantly better NPS and image quality scores for lung, soft tissue, and bone and with fewer beam-hardening artifacts (all P < .001). Image noise was significantly lower for PCD images in all BMI groups (P < .001 for groups 1 and 3, P < .01 for group 2), with higher CNR for lung nodule detection (12.1 ± 1.7 vs 10.0 ± 1.8, P < .001). Inter- and intrareader reproducibility were good (all ICC > 0.800). Conclusion Initial human experience with dose-reduced PCD chest CT demonstrated lower image noise compared with conventional EID CT, with better diagnostic quality and lung nodule CNR. © RSNA, 2017 Online supplemental material is available for this article.
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Fotometría/instrumentación , Exposición a la Radiación/prevención & control , Protección Radiológica/instrumentación , Radiografía Torácica/instrumentación , Tomografía Computarizada por Rayos X/instrumentación , Anciano , Diseño de Equipo , Análisis de Falla de Equipo , Estudios de Factibilidad , Humanos , Persona de Mediana Edad , Fotometría/métodos , Proyectos Piloto , Dosis de Radiación , Protección Radiológica/métodos , Radiografía Torácica/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/métodosRESUMEN
Purpose To determine reader and computed tomography (CT) scan variability for measurement of coronary plaque volume. Materials and Methods This HIPAA-compliant study followed Standards for Reporting of Diagnostic Accuracy guidelines. Baseline coronary CT angiography was performed in 40 prospectively enrolled subjects (mean age, 67 years ± 6 [standard deviation]) with asymptomatic hyperlipidemia by using a 320-detector row scanner (Aquilion One Vision; Toshiba, Otawara, Japan). Twenty of these subjects underwent coronary CT angiography repeated on a separate day with the same CT scanner (Toshiba, group 1); 20 subjects underwent repeat CT performed with a different CT scanner (Somatom Force; Siemens, Forchheim, Germany [group 2]). Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to assess interreader, intrareader, and interstudy reproducibility. Results Baseline and repeat coronary CT angiography scans were acquired within 19 days ± 6. Interreader and intrareader agreement rates were high for total, calcified, and noncalcified plaques for both CT scanners (all ICCs ≥ 0.96) without bias. Scanner variability was ±18.4% (coefficient of variation) with same-vendor follow-up. However, scanner variability increased to ±29.9% with different-vendor follow-up. The sample size to detect a 5% change in noncalcified plaque volume with 90% power and an α error of .05 was 286 subjects for same-CT scanner follow-up and 753 subjects with different-vendor follow-up. Conclusion State-of-the-art coronary CT angiography with same-vendor follow-up has good scan-rescan reproducibility, suggesting a role of coronary CT angiography in monitoring coronary artery plaque response to therapy. Differences between coronary CT angiography vendors resulted in lower scan-rescan reproducibility. © RSNA, 2016 Online supplemental material is available for this article.
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Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Placa Aterosclerótica/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Angiografía por Tomografía Computarizada/normas , Enfermedad de la Arteria Coronaria/patología , Humanos , Persona de Mediana Edad , Variaciones Dependientes del Observador , Placa Aterosclerótica/patología , Tomógrafos Computarizados por Rayos X/normasRESUMEN
PURPOSE: To evaluate the performance of a prototype photon-counting detector (PCD) computed tomography (CT) system for abdominal CT in humans and to compare the results with a conventional energy-integrating detector (EID). MATERIALS AND METHODS: The study was HIPAA-compliant and institutional review board-approved with informed consent. Fifteen asymptomatic volunteers (seven men; mean age, 58.2 years ± 9.8 [standard deviation]) were prospectively enrolled between September 2 and November 13, 2015. Radiation dose-matched delayed contrast agent-enhanced spiral and axial abdominal EID and PCD scans were acquired. Spiral images were scored for image quality (Wilcoxon signed-rank test) in five regions of interest by three radiologists blinded to the detector system, and the axial scans were used to assess Hounsfield unit accuracy in seven regions of interest (paired t test). Intraclass correlation coefficient (ICC) was used to assess reproducibility. PCD images were also used to calculate iodine concentration maps. Spatial resolution, noise-power spectrum, and Hounsfield unit accuracy of the systems were estimated by using a CT phantom. RESULTS: In both systems, scores were similar for image quality (median score, 4; P = .19), noise (median score, 3; P = .30), and artifact (median score, 1; P = .17), with good interrater agreement (image quality, noise, and artifact ICC: 0.84, 0.88, and 0.74, respectively). Hounsfield unit values, spatial resolution, and noise-power spectrum were also similar with the exception of mean Hounsfield unit value in the spinal canal, which was lower in the PCD than the EID images because of beam hardening (20 HU vs 36.5 HU; P < .001). Contrast-to-noise ratio of enhanced kidney tissue was improved with PCD iodine mapping compared with EID (5.2 ± 1.3 vs 4.0 ± 1.3; P < .001). CONCLUSION: The performance of PCD showed no statistically significant difference compared with EID when the abdomen was evaluated in a conventional scan mode. PCD provides spectral information, which may be used for material decomposition.
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Medios de Contraste , Radiografía Abdominal/instrumentación , Tomografía Computarizada por Rayos X/instrumentación , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fotones , Estudios Prospectivos , Interpretación de Imagen Radiográfica Asistida por Computador , Semiconductores , Sensibilidad y EspecificidadRESUMEN
Purpose To assess the relationship between total, calcified, and noncalcified coronary plaque burdens throughout the entire coronary vasculature at coronary computed tomographic (CT) angiography in relationship to cardiovascular risk factors in asymptomatic individuals with low-to-moderate risk. Materials and Methods This HIPAA-compliant study had institutional review board approval, and written informed consent was obtained. Two hundred two subjects were recruited to an ongoing prospective study designed to evaluate the effect of HMG-CoA reductase inhibitors on atherosclerosis. Eligible subjects were asymptomatic individuals older than 55 years who were eligible for statin therapy. Coronary CT angiography was performed by using a 320-detector row scanner. Coronary wall thickness and plaque were evaluated in all epicardial coronary arteries greater than 2 mm in diameter. Images were analyzed by using dedicated software involving an adaptive lumen attenuation algorithm. Total plaque index (calcified plus noncalcified plaque) was defined as plaque volume divided by vessel length. Multivariable regression analysis was performed to determine the relationship between risk factors and plaque indexes. Results The mean age of the subjects was 65.5 years ± 6.9 (standard deviation) (36% women), and the median coronary artery calcium (CAC) score was 73 (interquartile range, 1-434). The total coronary plaque index was higher in men than in women (42.06 mm(2) ± 9.22 vs 34.33 mm(2) ± 8.35; P < .001). In multivariable analysis controlling for all risk factors, total plaque index remained higher in men than in women (by 5.01 mm(2); P = .03) and in those with higher simvastatin doses (by 0.44 mm(2)/10 mg simvastatin dose equivalent; P = .02). Noncalcified plaque index was positively correlated with systolic blood pressure (ß = 0.80 mm(2)/10 mm Hg; P = .03), diabetes (ß = 4.47 mm(2); P = .03), and low-density lipoprotein (LDL) cholesterol level (ß = 0.04 mm(2)/mg/dL; P = .02); the association with LDL cholesterol level remained significant (P = .02) after additional adjustment for the CAC score. Conclusion LDL cholesterol level, systolic blood pressure, and diabetes were associated with noncalcified plaque burden at coronary CT angiography in asymptomatic individuals with low-to-moderate risk. (©) RSNA, 2015 Online supplemental material is available for this article.
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Enfermedades Asintomáticas , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Placa Aterosclerótica/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Anciano , Enfermedades Cardiovasculares/complicaciones , Enfermedades Cardiovasculares/epidemiología , Enfermedad de la Arteria Coronaria/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Placa Aterosclerótica/complicaciones , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Statin treatment is a potent lipid-lowering therapy associated with decreased cardiovascular risk and mortality. Recent studies including the PARADIGM trial have demonstrated the impact of statins on promoting calcified coronary plaque. HYPOTHESIS: The degree of systemic inflammation impacts the amount of increase in coronary plaque calcification over 2 years of statin treatment. METHODS: A subgroup of 142 participants was analyzed from the Risk Stratification with Image Guidance of HMG CoA Reductase Inhibitor Therapy (RIGHT) study (NCT01212900), who were on statin treatment and underwent cardiac computed tomography angiography (CCTA) at baseline and 2-year follow-up. This cohort was stratified by baseline median levels of high-sensitivity hs-CRP and analyzed with linear regressions using Stata-17 (StataCorp). RESULTS: In the high versus low hs-CRP group, patients with higher baseline median hs-CRP had increased BMI (median [IQR]; 29 [27-31] vs. 27 [24-28]; p < .001), hypertension (59% vs. 41%; p = .03), and LDL-C levels (97 [77-113] vs. 87 [75-97] mg/dl; p = .01). After 2 years of statin treatment, the high hs-CRP group had significant increase in dense-calcified coronary burden versus the low hs-CRP group (1.27 vs. 0.32 mm2 [100×]; p = .02), beyond adjustment (ß = .2; p = .03). CONCLUSIONS: Statin treatment over 2 years associated with a significant increase in coronary calcification in patients with higher systemic inflammation, as measured by hs-CRP. These findings suggest that systemic inflammation plays a role in coronary calcification and further studies should be performed to better elucidate these findings.
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Calcinosis , Enfermedad de la Arteria Coronaria , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Placa Aterosclerótica , Proteína C-Reactiva , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Progresión de la Enfermedad , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Inflamación/tratamiento farmacológico , Estudios Prospectivos , Medición de RiesgoRESUMEN
PURPOSE: Circulating tumor cells (CTC) are under investigation as a minimally invasive liquid biopsy that may improve risk stratification and treatment selection. CTCs uniquely allow for digital pathology of individual malignant cell morphology and marker expression. We compared CTC features and T-cell counts with survival endpoints in a cohort of patients with metastatic genitourinary cancer treated with combination immunotherapy. EXPERIMENTAL DESIGN: Markers evaluated included pan-CK/CD45/PD-L1/DAPI for CTCs and CD4/CD8/Ki-67/DAPI for T cells. ANOVA was used to compare CTC burden and T-cell populations across timepoints. Differences in survival and disease progression were evaluated using the maximum log-rank test. RESULTS: From December 2016 to January 2019, 183 samples from 81 patients were tested. CTCs were found in 75% of patients at baseline. CTC burden was associated with shorter overall survival (OS) at baseline (P = 0.022), but not on-therapy. Five morphologic subtypes were detected, and the presence of two specific subtypes with unique cellular features at baseline and on-therapy was associated with worse OS (0.9-2.3 vs. 28.2 months; P < 0.0001-0.013). Increasing CTC heterogeneity on-therapy had a trend toward worse OS (P = 0.045). PD-L1+ CTCs on-therapy were associated with worse OS (P < 0.01, cycle 2). Low baseline and on-therapy CD4/CD8 counts were also associated with poor OS and response category. CONCLUSIONS: Shorter survival may be associated with high CTC counts at baseline, presence of specific CTC morphologic subtypes, PD-L1+ CTCs, and low %CD4/8 T cells in patients with metastatic genitourinary cancer. A future study is warranted to validate the prognostic utility of CTC heterogeneity and detection of specific CTC morphologies.
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Biomarcadores de Tumor/análisis , Inmunoterapia/métodos , Células Neoplásicas Circulantes/patología , Linfocitos T/inmunología , Neoplasias Urogenitales/patología , Adulto , Anciano , Anciano de 80 o más Años , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Linfocitos T/clasificación , Neoplasias Urogenitales/inmunología , Neoplasias Urogenitales/terapia , Adulto JovenRESUMEN
Clinical use of cardiac cine CT imaging is limited by high radiation dose and low temporal resolution. To evaluate a low radiation dose, high temporal resolution cardiac cine CT protocol in human cardiac CT and phantom scans. CT scans of a circulating iodine target were reconstructed using the conventional single heartbeat half-scan (HS, approx. 175 ms temporal resolution) and the 3-heartbeat multi-segment (MS, approx. 58 ms) algorithms. Motion artifacts were quantified by the root-mean-square error (RMSE). Low-dose cardiac cine CT scans were performed in 55 subjects at a tube potential of 80 kVp and current of 80 mA. Image quality of HS and MS scans was assessed by blinded reader quality assessment, left ventricular (LV) free wall motion, and LV ejection rate. Motion artifacts in phantom scans were higher in HS than in MS reconstructions (RSME 188 and 117 HU, respectively; p = 0.001). Median radiation dose in human scans was 1.2 mSv. LV late diastolic filling was observed more frequently in MS than in HS images (42 vs. 26 subjects, respectively; p < 0.001). LV free wall systolic motion was more physiologic and had less error in MS than in HS reconstructions (sum-of-squared errors 34 vs. 45 mm2, respectively; p < 0.001), and LV peak ejection rate was higher in MS than in HS reconstructions (166 vs. 152 mL/s, respectively; p < 0.001). Cardiac cine CT imaging is feasible at a low radiation dose of 1.2 mSv. MS reconstruction showed improved imaging of rapid motion in phantom studies and human cardiac CTs.
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Corazón/diagnóstico por imagen , Interpretación de Imagen Radiográfica Asistida por Computador , Volumen Sistólico , Tomografía Computarizada por Rayos X , Función Ventricular Izquierda , Anciano , Artefactos , Estudios de Factibilidad , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Fantasmas de Imagen , Valor Predictivo de las Pruebas , Estudios Prospectivos , Dosis de Radiación , Exposición a la Radiación , Reproducibilidad de los Resultados , Factores de Tiempo , Tomografía Computarizada por Rayos X/instrumentaciónRESUMEN
PURPOSE: We assessed the safety and efficacy of cabozantinib and nivolumab (CaboNivo) and CaboNivo plus ipilimumab (CaboNivoIpi) in patients with metastatic urothelial carcinoma (mUC) and other genitourinary (GU) malignances. PATIENTS AND METHODS: Patients received escalating doses of CaboNivo or CaboNivoIpi. The primary objective was to establish a recommended phase II dose (RP2D). Secondary objectives included objective response rate (ORR), progression-free survival (PFS), duration of response (DoR), and overall survival (OS). RESULTS: Fifty-four patients were enrolled at eight dose levels with a median follow-up time of 44.6 months; data cutoff was January 20, 2020. Grade 3 or 4 treatment-related adverse events (AEs) occurred in 75% and 87% of patients treated with CaboNivo and CaboNivoIpi, respectively, and included fatigue (17% and 10%, respectively), diarrhea (4% and 7%, respectively), and hypertension (21% and 10%, respectively); grade 3 or 4 immune-related AEs included hepatitis (0% and 13%, respectively) and colitis (0% and 7%, respectively). The RP2D was cabozantinib 40 mg/d plus nivolumab 3 mg/kg for CaboNivo and cabozantinib 40 mg/d, nivolumab 3 mg/kg, and ipilimumab 1 mg/kg for CaboNivoIpi. ORR was 30.6% (95% CI, 20.0% to 47.5%) for all patients and 38.5% (95% CI, 13.9% to 68.4%) for patients with mUC. Median DoR was 21.0 months (95% CI, 5.4 to 24.1 months) for all patients and not reached for patients with mUC. Median PFS was 5.1 months (95% CI, 3.5 to 6.9 months) for all patients and 12.8 months (95% CI, 1.8 to 24.1 months) for patients with mUC. Median OS was 12.6 months (95% CI, 6.9 to 18.8 months) for all patients and 25.4 months (95% CI, 5.7 to 41.6 months) for patients with mUC. CONCLUSION: CaboNivo and CaboNivoIpi demonstrated manageable toxicities with durable responses and encouraging survival in patients with mUC and other GU tumors. Multiple phase II and III trials are ongoing for these combinations.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Células Transicionales/tratamiento farmacológico , Neoplasias Urogenitales/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Anilidas/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Antígeno B7-H1/metabolismo , Carcinoma de Células Transicionales/secundario , Colitis/inducido químicamente , Diarrea/inducido químicamente , Molécula de Adhesión Celular Epitelial/metabolismo , Fatiga/inducido químicamente , Femenino , Hepatitis/etiología , Humanos , Hipertensión/inducido químicamente , Ipilimumab/administración & dosificación , Masculino , Persona de Mediana Edad , Células Neoplásicas Circulantes/metabolismo , Nivolumab/administración & dosificación , Supervivencia sin Progresión , Proteínas Proto-Oncogénicas c-met/metabolismo , Piridinas/administración & dosificación , Receptores CXCR4/metabolismo , Criterios de Evaluación de Respuesta en Tumores Sólidos , Tasa de Supervivencia , Adulto JovenRESUMEN
To evaluate the performance of photon-counting detector (PCD) computed tomography (CT) for coronary artery calcium (CAC) score imaging at standard and reduced radiation doses compared to conventional energy-integrating detector (EID) CT. A dedicated cardiac CT phantom, ten ex vivo human hearts, and ten asymptomatic volunteers underwent matched EID and PCD CT scans at different dose settings without ECG gating. CAC score, contrast, and contrast-to-noise ratio (CNR) were calculated in the cardiac CT phantom. CAC score accuracy and reproducibility was assessed in the ex vivo hearts. Standard radiation dose (120 kVp, reference mAs = 80) in vivo CAC scans were compared against dose-reduced CAC scans (75% dose reduction; reference mAs = 20) for image quality and CAC score reproducibility. Interstudy agreement was assessed by using intraclass correlation (ICC), linear regression, and Bland-Altman analysis with 95% confidence interval limits of agreement (LOA). Calcium-soft tissue contrast and CNR were significantly higher for the PCD CAC scans in the cardiac CT phantom (all P < 0.01). Ex vivo hearts: CAC score reproducibility was significantly higher for the PCD scans at the lowest dose setting (50 mAs) (P = 0.002); score accuracy was similar for both detector systems at all dose settings. In vivo scans: the agreement between standard dose and low dose CAC score was significantly better for the PCD than for the EID with narrower LOA in Bland-Altman analysis, linear regression slopes closer to 1 (0.96 vs. 0.84), and higher ICC values (0.98 vs. 0.93, respectively). Phantom and in vivo human studies showed PCD may significantly improve CAC score image quality and/or reduce CAC score radiation dose while maintaining diagnostic image quality.
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Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Fotones , Calcificación Vascular/diagnóstico por imagen , Anciano , Angiografía por Tomografía Computarizada/instrumentación , Angiografía Coronaria/instrumentación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fantasmas de Imagen , Valor Predictivo de las Pruebas , Estudios Prospectivos , Dosis de Radiación , Exposición a la Radiación/prevención & control , Reproducibilidad de los Resultados , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: To optimize spectral coronary computed tomography angiography (CTA) for quantification of coronary artery plaque components. MATERIALS AND METHODS: Fifty-one subjects were prospectively enrolled (88.2% male) (NCT02740699). Dual energy coronary CTA was performed at 90/Sn150â¯kVp using a 3rd generation dual-source CT scanner (SOMATOM Force, Siemens Healthcare). Dual energy images were reconstructed with a) linear mixed blending of 90 and Sn150â¯kVp data, b) virtual monoenergetic algorithm from 40 to 150â¯keV (at 10- keV intervals), and c) noise-optimized virtual monoenergetic algorithm from 40 to 150â¯keV. Image noise, iodine signal-to-noise-ratio (SNR), and contrast-to-noise ratio (CNR) for calcified and non-calcified plaque were measured. Qualitative readings of image quality were performed. Semi-automated software (QAngioCT, Medis) was used to quantify coronary plaque. Linear mixed-models that account for within-subject correlation of plaques were used to compare the results. RESULTS: 100-150â¯keV noise-optimized virtual monoenergetic images had lower image noise than linear mixed images (all Pâ¯<â¯0.05). The highest iodine SNR was achieved in 40â¯keV noise-optimized virtual monoenergetic images (33.3⯱â¯0.6 vs 23.3⯱â¯0.7 for linear mixed images, Pâ¯<â¯0.001). 40-70â¯keV noise-optimized virtual monoenergetic images and 70â¯keV virtual monoenergetic images had superior coronary plaque CNR versus linear mixed images (all Pâ¯<â¯0.01) with a maximum improvement of 20.1% and 22.7% for calcified plaque and non-calcified plaque (38.8⯱â¯2.2 vs 32.3⯱â¯2.3 and 17.3⯱â¯1.3 vs 14.1⯱â¯1.4, respectively). Using 90/Sn150â¯kVp linear mixed images as a reference, the plaque quantity was similar for 70â¯keV noise-optimized virtual monoenergetic images whereas low keV images (e.g. 40â¯keV) yielded significantly higher coronary plaque volumes (all Pâ¯<â¯0.001). CONCLUSION: Spectral coronary CTA with low energy (40-70â¯keV) post-processing can improve the CNR of coronary plaque components. However, low energies (such as 40â¯keV) resulted in different absolute volumes of coronary plaque compared to "conventional" mixed 90/Sn150â¯kVp images.
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Angiografía por Tomografía Computarizada , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Placa Aterosclerótica , Anciano , Enfermedad de la Arteria Coronaria/patología , Vasos Coronarios/patología , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Interpretación de Imagen Radiográfica Asistida por Computador , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/patologíaRESUMEN
INTRODUCTION: 18Fluorodeoxyglucose (FDG) positron emission tomography (PET) uptake in the artery wall correlates with active inflammation. However, in part due to the low spatial resolution of PET, variation in the apparent arterial wall signal may be influenced by variation in blood FDG activity that cannot be fully corrected for using typical normalization strategies. The purpose of this study was to evaluate the ability of the current common methods to normalize for blood activity and to investigate alternative methods for more accurate quantification of vascular inflammation. MATERIALS AND METHODS: The relationship between maximum FDG aorta wall activity and mean blood activity was evaluated in 37 prospectively enrolled subjects aged 55 years or more, treated for hyperlipidemia. Target maximum aorta standardized uptake value (SUV) and mean background reference tissue activity (blood, spleen, liver) were recorded. Target-to-background ratios (TBR) and arterial maximum activity minus blood activity were calculated. Multivariable regression was conducted, predicting uptake values based on variation in background reference and target tissue FDG uptake; adjusting for gender, age, lean body mass (LBM), blood glucose, blood pool activity, and glomerular filtration rate (GFR), where appropriate. RESULTS: Blood pool activity was positively associated with maximum artery wall SUV (ß = 5.61, P<0.0001) as well as mean liver (ß = 6.23, P<0.0001) and spleen SUV (ß = 5.20, P<0.0001). Artery wall activity divided by blood activity (TBRBlood) or subtraction of blood activity did not remove the statistically significant relationship to blood activity. Blood pool activity was not related to TBRliver and TBRspleen (ß = -0.36, P = NS and ß = -0.58, P = NS, respectively). CONCLUSIONS: In otherwise healthy individuals treated for hyperlipidemia, blood FDG activity is associated with artery wall activity. However, variation in blood activity may mask artery wall signal reflective of inflammation, which requires normalization. Blood-based TBR and subtraction do not sufficiently adjust for blood activity. Warranting further investigation, background reference tissues with cellular uptake such as the liver and spleen may better adjust for variation in blood activity to improve assessment of vascular activity.
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Ensayos Clínicos como Asunto , Fluorodesoxiglucosa F18/administración & dosificación , Radiofármacos/administración & dosificación , Vasculitis/diagnóstico por imagen , Anciano , Aterosclerosis/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Imagen Multimodal , Tomografía de Emisión de Positrones , Estudios Prospectivos , Tomografía Computarizada por Rayos XRESUMEN
BACKGROUND: This study aimed to determine the relationship of statin therapy and cardiovascular risk factors to changes in atherosclerosis in the carotid artery. METHODS AND RESULTS: Carotid magnetic resonance imaging was used to evaluate 106 hyperlipidemic participants at baseline and after 12 months of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) treatment. Multivariable logistic regression was used to determine factors associated with progression (change in carotid wall volume >0) or regression (change ≤0) of carotid atherosclerosis. Computed tomography coronary calcium scores were obtained at baseline for all participants. The median age was 65 years (interquartile range 60-69 years), and 63% of the participants were male. Body mass index >30, elevated C-reactive protein, and hypertension were associated with increased carotid wall volume (obesity: odds ratio for progression 4.6, 95% CI 1.8-12.4, P<0.01; C-reactive protein: odds ratio for progression 2.56, 95% CI 1.17-5.73, P=0.02; hypertension: odds ratio 2.4, 95% CI 1.1-5.3, P<0.05). Higher statin dose was associated with regression of carotid wall volume (P<0.05). In multivariable analysis, obesity remained associated with progression (P<0.01), whereas statin use remained associated with regression (P<0.05). Change in atheroma volume in obese participants was +4.8% versus -4.2% in nonobese participants (P<0.05) despite greater low-density lipoprotein cholesterol reduction in obese participants. CONCLUSIONS: In a population with hyperlipidemia, obese patients showed atheroma progression despite optimized statin therapy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01212900.