Predictive value of FLAIR signal intensity ratio in onset time≤4.5 h in acute ischemic stroke patients with poor collateral circulation / 中华神经医学杂志

Objective:To investigate the predictive value of fluid-attenuated inversion recovery (FLAIR) signal strength ratio (SIR) in onset time≤4.5 h in patients with acute ischemic stroke.Methods:A retrospective analysis was performed; 180 acute ischemic stroke patients admitted to Department of Neurology, Nanjing Hospital Affiliated to Nanjing Medical University from January 2020 to June 2023 were chosen. Hypoperfusion intensity ratio (HIR) was used to evaluate the collateral circulation (poor collateral circulation: HIR≤0.4; good collateral circulation: HIR>0.4); clinical data and imaging indexes between poor collateral circulation and good collateral circulation groups were compared. Univariate and multivariate Logistic regressions were used to analyze the influencing factors for onset time≤4.5 h in patients with acute ischemic stroke. Correlation between SIR and onset time was analyzed in patients with acute ischemic stroke. Role of HIR as agency between SIR and onset time was explored. Receiver operating characteristic (ROC) curve was used to analyze the predictive efficacy of SIR and diffusion weighted imaging (DWI)-FLAIR mismatch in onset time≤4.5 h in acute ischemic stroke patients.Results:Of the 180 patients, 100 were into the good collateral circulation group and 80 were into the poor collateral circulation group; compared with the good collateral circulation group, the poor collateral circulation group had significantly higher percentage of patients with hyperlipidemia, larger DWI infarction volume before treatment, larger perfusion weighted imaging (PWI)-DWI mismatch volume and higher SIR ( P<0.05). In these 180 patients, 76 had onset time≤4.5 h and 104 had onset time>4.5 h. Univariate Logistic regression analysis showed that hyperlipidemia, DWI infarct volume before treatment, DWI-FLAIR mismatch, HIR and SIR were influencing factors for onset time≤4.5 h in acute ischemic stroke patients ( P<0.05). Multivariate Logistic regression analysis showed that hyperlipidemia ( OR=6.654, 95% CI: 5.751-8.824, P<0.001), HIR ( OR=0.724, 95% CI: 0.521-1.321, P=0.041) and SIR ( OR=739.881, 95% CI: 383.296-14 258.065, P<0.001) were independent influencing factors for onset time≤4.5 h in acute ischemic stroke patients. Pearson correlation analysis showed that SIR was positively correlated to onset time in patients with acute ischemic stroke ( r=0.420, P<0.05), and SIR was positively correlated to onset time in patients from poor collateral circulation group ( r=0.781, P<0.05). ROC curve showed that AUC of SIR in predicting onset time≤4.5 h was 0.917 (95% CI: 0.814-1.000, P<0.001) and that of DWI-FLAIR mismatch in predicting onset time≤4.5 h was 0.530 (95% CI: 0.509-0.757, P=0.075) in poor collateral circulation group, enjoying significant difference in predictive efficacy. Conclusion:Acute ischemic stroke patients with low HIR and SIR have higher odds of onset time≤4.5 h; SIR can more accurately predict the onset time in these patients with poor collateral circulation.

Inmunoensayo quimioluminiscente para sífilis en donantes de sangre: ¿Los valores de lectura se correlacionan con el estado de la infección? / Chemiluminescent immunoassay for syphilis in blood donors: do signal strength values correlate with the infection status? / Imunoensaio quimioluminescente para sífilis em doadores de sangue: os valores de leitura estão correlacionados com o estado da infecção?

Resumen El objetivo del trabajo fue comparar el desempeño del tamizaje treponémico y no treponémico en dos períodos próximos en el tiempo en donantes de sangre y analizar la asociación de la intensidad de la señal de la prueba quimioluminiscente (QL) con la reactividad del enzimoinmunoanálisis (ELISA) y la reagina plasmática rápida (RPR). Se realizó el tamizaje con pruebas treponémicas. Se analizó la distribución de los valores de señal/valor de corte (S/CO) obtenidos por QL en función del ELISA y RPR y se evaluó su asociación entre dos grupos de resultados de laboratorio (1) ELISA+/RPR+ y (2): ELISA+/RPR-. Se procesaron 76 794 donaciones voluntarias. Al comparar las medianas entre grupos, se encontró que la relación S/CO de QL fue significativamente mayor para los donantes del Grupo 1 (19,5 vs. 8,10; p<0,001). Se concluye que la intensidad de la señal de la prueba cualitativa QL estaría asociada con la reactividad de la RPR y guardaría relación con el curso de la infección.

Abstract The objective of this work was to compare the performance of treponemal and non-treponemal screening in two periods close in time in blood donors and to analyse the association of the signal strength (signal-to-cutoff, S/ CO) of the chemiluminescent immunoassay (CIA) with the reactivity of the enzymeimmunoassay (EIA) and the rapid plasma reagin (RPR). Donors were screened with treponemal tests. The distribution of the S/CO values obtained by CIA was analysed based on EIA and RPR, and its association was evaluated. Group 1: ELISA+/RPR+ donors and Group 2: ELISA+/RPR-. A total of 76,794 voluntary donations were processed. Comparing the means between groups, it was found that the CIA S/CO ratio was significantly higher for Group 1 donors (19.5 vs. 8.10; p<0.001). In conclusion, the signal strength of the qualitative CIA test would be associated with the reactivity of the RPR and would be related to the course of the infection.

Resumo O objetivo do trabalho foi comparar o desempenho da triagem treponêmica e não treponêmica em dois períodos próximos no tempo em doadores de sangue e analisar a associação da intensidade do sinal da prova quimioluminescente (QL) com a reatividade da análise imunoenzimática (ELISA) e a reagina plasmática rápida (RPR). Foi realizada uma triagem com provas treponêmicas. Foi analisada a distribuição dos valores de sinal/valor de corte (S/CO) obtidos por QL em função da ELISA e RPR, e também a associação entre dois grupos de resultados laboratoriais (1): ELISA+/RPR+ e (2) ELISA+/ RPR-). Foram procesadas 76 794 doações de sangue voluntárias. Ao comparar as medianas entre os grupos, obteve-se que a relação S/CO de QL foi significativamente maior para os doadores de sangue do grupo 1 (19,5 vs. 8,10; p<0,001). Em conclusão, a intensidade do sinal da prova qualitativa QL estaria associada com a reatividade da RPR e guardaria relação com o curso da infecção.

Comparison of retinal nerve fiber layer thickness under low and moderate signal strength / 实用医学杂志

Objective To investigate the difference of retinal nerve fiber layer thickness(RNFL)in opti-cal coherence tomography(OCT)under low and moderate signal strength. Methods Four hundred eyes of people aged 46~75 with clear fundus image,no obvious fundus diseases,and satisfactory optical coherence tomography were classified according to their ages and signal strength. The peripapillary and 4 quadrants of RNFL were detect-ed with OCT. Results In satisfactory OCT images ,the signal strength that reached 4/10 and 7/10 was 1.5% and 27% respectively. Under low and moderate signal strength ,the maximum thickness of RNFL was at the superior and inferior,and the minimum thickness of RNFL was at the nasal and temporal. There were no significant differ-ences in RNFL thickness under low or moderate signal strength. Conclusion RNFL results are reliable under low and moderate signal strength.

The Effect of Machine Aging on the Measurements of Optical Coherency Tomography

PURPOSE: To evaluate the effect of instrument aging on optical coherence tomography (OCT) measurements. METHODS: Single eyes of 60 healthy participants (60 eyes) aged 20-30 years were examined twice using a 5-year-old OCT instrument and a new OCT instrument (Carl Zeiss Meditec, Dublin, CA, USA). The measurements and changes in signal strength were investigated using both instruments. RESULTS: The signal strengths of the new and aged instruments were 8.6 ± 0.8 and 5.0 ± 1.0, respectively, which was a statistically significant difference (p < 0.001). In addition, the central macular thicknesses (CMT) of the new and aged instruments were 201.1 ± 16.1 µm and 210.3 ± 16.0 µm, respectively. The thickness was significantly greater using the aged instrument (p < 0.001). Repeated measurements within the same eye were compared, and the difference in CMT was 3.2 using the new instrument and 10.5 using the aged instrument (p < 0.05). The intraclass correlation coefficient (ICC) was compared to evaluate the reproducibility of each instrument. The ICC values of nine areas of Early Treatment Diabetic Retinopathy Study in the aged instrument were 0.371-0.872, indicating low reproducibility. However, the new instrument showed high reproducibility with values of 0.806-0.947. CONCLUSIONS: Higher signal strength and lower CMT were observed using the new instrument compared to the aged instrument. Additionally, there were no differences in signal strength errors between the instruments. However, the error in CMT measured using the new instrument was significantly smaller compared to that using the aged instrument. Therefore, the effect of instrument aging should be accounted for in analyses of OCT measurements.

Low Limit for Effective Signal Strength in the Stratus OCT in Imperative Low Signal Strength Cases

PURPOSE: To determine the lowest limit of signal strength that is still effective for accurate analysis of optic coherence tomography (OCT) values, we investigated the reproducibility of OCT scans by signal strength (SS). METHODS: A total of 668 subjects were scanned for measurements of retinal nerve fiber layer (RNFL) thickness using the Stratus OCT twice on the same day. The variability of overall RNFL thickness parameters obtained at different SS was analyzed and compared by repeated-measures of ANOVA and Spearman's correlation coefficient. Values of the intraclass correlation coefficient (ICC) and variability (standard deviation) of RNFL thickness were obtained. The false positive ratio was analyzed. RESULTS: When SS was 3, the variability of RNFL thickness was significantly different (low ICC, high variability) in comparison to when SS was 4 or greater. Significant negative correlations were observed between variability in RNFL thickness and signal strength. The difference of variability of average RNFL thickness between SS 4 (4.94 microm) and SS 6 (4.41 microm) was 0.53 microm. CONCLUSIONS: Clinically, the difference of variability of average RNFL thickness between SS 4 and SS 6 was quite small. High SS is important, however, when signal strength is low due to uncorrectable factors in patients in need of OCT for glaucoma and retinal disease. Our results suggest that SS 4 is the lowest acceptable limit of signal strength for obtaining reproducible scanning images.

Analysis of Factors Associated with Variability in Measures Obtained by Spectral Domain Optical Coherence Tomography

PURPOSE: To identify factors associated with variability in measures obtained by spectral domain optical coherence tomography (SD-OCT). METHODS: One hundred ninety-six subjects (370 eyes) with no ophthalmic evidence of retinopathy and with corrected visual acuities better than 0.6 were included. Macular thickness and retinal nerve fiber layer (RNFL) thickness were measured using SD-OCT and were analyzed according to sex, laterality, age, spherical equivalent and signal strength. RESULTS: The central subfield thickness was significantly lower in the female subjects (r = -0.260, p = 0.000). As age increased, average inner and outer macular thickness increased significantly (r = 0.153, p = 0.010; r = 0.193, p = 0.001). Spherical equivalent correlated negatively with central subfield thickness (r = -0.352, p = 0.000) but correlated positively with average inner macular thickness, average outer macular thickness, overall average thickness, overall macular volume, and average RNFL thickness (r = 0.181, p = 0.002; r = 0.287, p = 0.000; r = 0.346, p = 0.000; r = 0.341, p = 0.000; and r = 0.261, p = 0.000, respectively). Signal strength correlated negatively with average inner macular thickness (r = -0.136, p = 0.023). CONCLUSIONS: SD-OCT shows that retinal thickness is related to age, sex, spherical equivalent and signal strength. Analysis of retinal thickness by SD-OCT should be interpreted in the context of these findings.

Factors Associated with the Signal Strengths Obtained by Spectral Domain Optical Coherence Tomography

PURPOSE: The aim of this study was to investigate factors associated with the signal strengths (SS, image quality scores) of optic disc and macular images obtained using Cirrus spectral domain optical coherence tomography (OCT). METHODS: Ninety-two glaucomatous eyes were imaged using the Cirrus OCT macular and optic disc cube modes after pupil dilation. The influences of patient age, spherical equivalent, cataract presence, and cataract and glaucoma severity (visual field mean deviation), on the SS of images obtained using the two cube modes were compared between patients whose images showed high SS (SS > or =7) and low SS (SS <7). RESULTS: The signal strength was significantly higher in images obtained using the macular cube compared to the optic disc cube mode (7.8 +/- 1.3 vs. 6.9 +/- 1.1, respectively; p = 0.001). Age and visual acuity of patients differed significantly between the high- and low-SS groups when data acquired using the optic disc (p = 0.027 and 0.012, respectively) and macular cube modes (p = 0.046 and 0.014, respectively) were analyzed. When the optic disc cube mode was employed, the extent of cataracts was significantly related to SS, whereas when the macular cube mode was used, none of the factors analyzed was significantly associated with SS. CONCLUSIONS: Age, visual acuity, and the extent of cataracts were significantly associated with images of higher SS when the Cirrus OCT optic disc cube mode was employed.

A Study on the Patient Location Monitoring System Based on RFID - RSSI / 대한의료정보학회지

OBJECTIVE: The location services has been an important research area in the U-Healthcare. The location services in medical environment can be implemented by Radio Frequency Identification (RFID), and Received Signal Strength Indication (RSSI) which is the location tracking method by RFID. In this study, we was designed the Patient Location Monitoring System based on RFID using RSSI method. METHODS: The RSSI method is a distance measurement method from reference points to object using the Friis's Principle and the Triangulation. The Patient Location Monitoring System was implemented by XML Data transmitted from the Positioning Server to the application. The Patient Location Monitoring System was designed by C# of Visual Studio 2005 and MS-SQL 2005 Express. RESULTS: The Patient Location Monitoring System had the location-tracking average error of 90.50cm, the standard-deviation of 13.34cm in Open-Space test. And, the designed system had the location-tracking average error of 163.24cm, the standard-deviation of 16.85cm in Closed-Space Test. Also, a patient waiting-list guide performance of the Patient Location Monitoring System had successes of 85~100%. CONCLUSION: In this study, the Patient Location Monitoring System, combined with both patient location-tracking function and patient waiting-list guide function, was validated by experiments in medical environment and this system can be applicable to patient management and further applications.