CT value of the intestine is useful predictor for differentiate irreversible ischaemic changes in strangulated ileus

Real-time RT-PCR is considered the gold standard confirmatory test for coronavirus disease 2019 (COVID-19). However, many scientists disagree, and it is essential to understand that several factors and variables can cause a false-negative test. In this context, cycle threshold (Ct) values are being utilized to diagnose or predict SARS-CoV-2 infection. This practice has a significant clinical utility as Ct values can be correlated with the viral load. In addition, Ct values have a strong correlation with multiple haematological and biochemical markers. However, it is essential to consider that Ct values might be affected by pre-analytic, analytic, and post-analytical variables such as collection technique, specimen type, sampling time, viral kinetics, transport and storage conditions, nucleic acid extraction, viral RNA load, primer designing, real-time PCR efficiency, and Ct value determination method. Therefore, understanding the interpretation of Ct values and other influential factors could play a crucial role in interpreting viral load and disease severity. In several clinical studies consisting of small or large sample sizes, several discrepancies exist regarding a significant positive correlation between the Ct value and disease severity in COVID-19. In this context, a revised review of the literature has been conducted to fill the knowledge gaps regarding the correlations between Ct values and severity/fatality rates of patients with COVID-19. Various databases such as PubMed, Science Direct, Medline, Scopus, and Google Scholar were searched up to April 2021 by using keywords including “RT-PCR or viral load”, “SARS-CoV-2 and RT-PCR”, “Ct value and viral load”, “Ct value or COVID-19”. Research articles were extracted and selected independently by the authors and included in the present review based on their relevance to the study. The current narrative review explores the correlation of Ct values with mortality, disease progression, severity, and infectivity. We also discuss the factors that can affect these values, such as collection technique, type of swab, sampling method, etc.

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Lack of correlation between the SARS‐CoV‐2 cycle threshold (Ct) value and clinical outcomes in patients with COVID‐19

Journal of Medical Virology ◽

10.1002/jmv.27171 ◽

2021 ◽

Author(s):

Jose F Camargo ◽

Rick Y Lin ◽

Krishna V Komanduri

Keyword(s):

Clinical Outcomes ◽

Cycle Threshold ◽

Ct Value

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414. Association of SARS-CoV-2 Genomic Load Trends with Clinical Status in COVID-19:A Retrospective Analysis from an Academic Hospital Center in New York City

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa439.608 ◽

2020 ◽

Vol 7 (Supplement_1) ◽

pp. S275-S275

Author(s):

Ioannis Zacharioudakis ◽

Fainareti Zervou ◽

Prithiv Prasad ◽

Yongzhao Shao ◽

Atreyee Basu ◽

...

Keyword(s):

New York ◽

Sofa Score ◽

Research Question ◽

Clinical Status ◽

Inverse Correlation ◽

Duration Of Symptoms ◽

Cycle Threshold ◽

Ct Value ◽

Failure Assessment ◽

Polymerase Chain

Abstract Background The Infectious Diseases Society of America has identified the potential use of SARS-CoV-2 genomic load for prognostication purposes as a key research question. Methods We designed a retrospective cohort study that included adult patients with COVID-19 pneumonia who had at least 2 positive nasopharyngeal tests at least 24 hours apart to study the correlation between the change in the genomic load of SARS-CoV-2 in nasopharyngeal samples, as reflected by the Cycle threshold (Ct) value of the real-time Polymerase Chain Reaction (PCR) assay, with change in clinical status. The Sequential Organ Failure Assessment (SOFA) score was used as a surrogate for patients’ clinical status. A linear mixed-effects regression analysis was performed. Results Among 457 patients who presented to the emergency department between 3/31/2020- 4/10/2020, we identified 42 patients who met the inclusion criteria. The median initial SOFA score was 2 (IQR 2–3). 20 out of 42 patients had a lower SOFA score on their subsequent tests. We identified a statistically significant inverse correlation between the change in SOFA score and change in the Ct value with a decrease in SOFA score by 0.05 (SE 0.02; p < 0.05) for an increase in Ct values by 1. This correlation was independent of the duration of symptoms. Flow chart A graph of the Cycle Threshold (Ct) values of the of Cepheid Xpert® Xpress SARS-CoV-2 assay measured on repeat screening of the 42 included patients. Graph of the fitted SOFA scores based on the Cycle Threshold values per patient. Conclusion Our findings suggest that an increasing Ct value in sequential tests may be of prognostic value for patients diagnosed with COVID-19 pneumonia. Before repeat testing can be recommended routinely in clinical practice as a predictor of disease outcomes, prospective studies with a standardized interval between repeat tests should confirm our findings. Disclosures All Authors: No reported disclosures

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Baseline Xpert MTB/RIF ct values predict sputum conversion during the intensive phase of anti-TB treatment in HIV infected patients in Kampala, Uganda: a retrospective study

BMC Infectious Diseases ◽

10.1186/s12879-021-06220-6 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Juliet Namugenyi ◽

Joseph Musaazi ◽

Achilles Katamba ◽

Joan Kalyango ◽

Emmanuel Sendaula ◽

...

Keyword(s):

Bacterial Load ◽

Sputum Smear ◽

People Living With Hiv ◽

Cd4 Cell Count ◽

Cut Point ◽

Ct Value ◽

Tb Treatment ◽

Drug Concentrations ◽

Unit Increase ◽

Sputum Conversion

Abstract Background In resource-limited settings, sputum smear conversion is used to document treatment response. Many People living with HIV (PLHIV) are smear-negative at baseline. The Xpert MTB/RIF test can indirectly measure bacterial load through cycle threshold (ct) values. This study aimed to determine if baseline Xpert MTB/RIF could predict time to culture negativity in PLHIV with newly diagnosed TB. Methods A subset of 138 PLHIV from the ‘SOUTH’ study on outcomes related to TB and antiretroviral drug concentrations were included. Bacterial load was estimated by Mycobacterium Growth Indicator Tubes (MGIT) culture time-to-positivity (TTP) and Lowenstein Jensen (LJ) colony counts. Changes in TTP and colony counts were analyzed with Poisson Generalised Estimating Equations (GEE) and multilevel ordered logistic regression models, respectively, while time to culture negativity analysed with Cox proportional hazard models. ROC curves were used to explore the accuracy of the ct value in predicting culture negativity. Results A total of 81 patients (58.7%) were males, median age 34 (IQR 29 ̶ 40) years, median CD4 cell count of 180 (IQR 68 ̶ 345) cells/μL and 77.5% were ART naive. The median baseline ct value was 25.1 (IQR 21.0 ̶ 30.1). A unit Increase in the ct value was associated with a 5% (IRR = 1.05 95% CI 1.04 ̶ 1.06) and 3% (IRR = 1.03 95% CI 1.03 ̶ 1.04) increase in TTP at week 2 and 4 respectively. With LJ culture, a patient’s colony grade was reduced by 0.86 times (0R = 0.86 95% CI 0.74 ̶ 0.97) at week 2 and 0.84 times (OR = 0.84 95% CI 0.79 ̶ 0.95 P = 0.002) at week 4 for every unit increase in the baseline ct value. There was a 3% higher likelihood of earlier conversion to negativity for every unit increase in the ct value. A ct cut point ≥28 best predicted culture negativity at week 4 with a sensitivity of 91. 7% & specificity 53.7% while a cut point ≥23 best predicted culture negativity at week 8. Conclusion Baseline Xpert MTB/RIF ct values predict sputum conversion in PLHIV on anti-TB treatment. Surrogate biomarkers for sputum conversion in PLHIV are still a research priority.

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Rapid switching kVp dual energy CT: Value of reconstructed dual energy CT images and organ dose assessment in multiphasic liver CT exams

European Journal of Radiology ◽

10.1016/j.ejrad.2018.02.022 ◽

2018 ◽

Vol 102 ◽

pp. 102-108 ◽

Cited By ~ 11

Author(s):

Usman Mahmood ◽

Natally Horvat ◽

Joao Vicente Horvat ◽

Davinia Ryan ◽

Yiming Gao ◽

...

Keyword(s):

Organ Dose ◽

Ct Images ◽

Dual Energy ◽

Dose Assessment ◽

Dual Energy Ct ◽

Liver Ct ◽

Ct Value ◽

Rapid Switching

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Randomized response surface pathway design with skewed starting point and stochastic dose window

International Journal of Clinical Trials ◽

10.18203/2349-3259.ijct20200202 ◽

2020 ◽

Vol 7 (1) ◽

pp. 18

Author(s):

Trond Holand ◽

Øystein Evensen ◽

Sagita Dewi ◽

Stig Larsen

Keyword(s):

Atlantic Salmon ◽

Response Surface ◽

Initial Dose ◽

Salt Water ◽

Lower Boundary ◽

Response Variable ◽

Ct Value ◽

Starting Point ◽

Starting Dose ◽

The Mean

Background: The aim was to introduce response surface pathway (RSP)-design with skewed starting value and stochastic dose-window to estimate optimal efficacy dose (OED) of BP-C2 after IL-1β stimulation in Atlantic salmon.Methods: 54 healthy smolt of Atlantic salmon between 50 and 100 g before habituated to salt water were included. The study was conducted as a one-dimensional, randomized between-patient three-level RSP designed trial with one interventional- and one response variable and odd outcomes. The interventional variable was intraperitoneal injected BPC2 with skewed starting dose of 0.10 mg/100 g related to the initial dose-window <0.02-0.5 mg/100 g. The response variable was the Ct-value of mRNA IL-1β expression 24 hours after injection.Results: Skewed starting value of 0.10 mg/100 g was chosen in the first design-level with a dose-window of <0.0-0.20]. The three smolt obtained a reduction in Ct-value above 15%, and the dose-window adjusted with the lower boundary equals the previous dose. The five smolt at second design-level received 0.16 mg/100g with a dose-window [0.10-0.22]. Four smolt obtained above 15% and one of 0.5% reduction in cycle threshold (Ct)-value. Six smolt in the third design-level received 0.21 mg/100 g and one 0.16 mg/100 g. The mean Ct-value was reduced from 30.0 in the unstimulated situation to 25.0, 24.8 and 26.4 after BP-C2 stimulation of 0.10, 0.16 and 0.21 mg/100 g, respectively. The OED of BP-C2 related to IL-1β was estimated to 0.14 mg/100 g.Conclusions: Skewed starting value in the initial dose-window made the K-adjustment factor and dose-window stochastic. The RSP-procedure works in accordance to the expectation and estimated OED of BP-C2 sufficiently.

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111 In-pentetreotide SPECT CT Value in Follow-up of Patients with Neuro-Endocrine Tumors

Oman Medical Journal ◽

10.5001/omj.2014.95 ◽

2014 ◽

Vol 29 (5) ◽

pp. 362-364 ◽

Cited By ~ 2

Author(s):

Badriya Al-Suqri

Keyword(s):

Endocrine Tumors ◽

Ct Value

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Exploring the best monochromatic energy level in dual energy spectral imaging for coronary stents after percutaneous coronary intervention

Scientific Reports ◽

10.1038/s41598-021-97035-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Qian Liu ◽

Yajuan Wang ◽

Haicheng Qi ◽

Yaohui Yu ◽

Yan Xing

Keyword(s):

Percutaneous Coronary Intervention ◽

Energy Level ◽

Coronary Intervention ◽

Dual Energy ◽

Spectral Ct ◽

Beam Hardening ◽

Subjective Image Quality ◽

Ct Value ◽

Percutaneous Coronary

AbstractIn this study, the optimal monochromatic energy level in dual-energy spectral CT required for imaging coronary stents after percutaneous coronary intervention (PCI) was explored. Thirty-five consecutive patients after PCI were examined using the dual-energy spectral CT imaging mode. The original images were reconstructed at 40–140 keV (10-keV interval) monochromatic levels. The in-stent and out-stent CT values at each monochromatic level were measured to calculate the signal-to-noise ratio(SNR) and contrast-to-noise ratio (CNR) for the vessel and the CT value difference between the in-stent and out-stent lumen (dCT (in–out)), which reflects the artificial CT number increase due to the beam hardening effect caused by the stents. The subjective image quality of the stent and in-stent vessel was evaluated by two radiologists using a 5-point scale. With the increase in energy level, the CT value, SNR, CNR, and dCT (in–out) all decreased. At 80 keV, the mean CT value in-stent reached (345.24 ± 93.43) HU and dCT (in–out) started plateauing. In addition, the subjective image quality of the stents and vessels peaked at 80 keV. The 80 keV monochromatic images are optimal for imaging cardiac patients with stents after PCI, balancing the enhancement and SNR and CNR in the vessels while minimizing the beam hardening artifacts caused by the stents.

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Direct detection of microorganisms responsible for the sexually transmitted infection on the mobile real-time PCR device without treating in advance

10.1101/2021.03.02.21252726 ◽

2021 ◽

Author(s):

Masaaki Muraoka ◽

Kazunori Sohma ◽

Osamu Kawaguchi ◽

Mikio Mizukoshi

Keyword(s):

Real Time ◽

Real Time Pcr ◽

Limit Of Detection ◽

Direct Detection ◽

Treponema Pallidum ◽

Nucleic Acid Amplification ◽

Direct Pcr ◽

Transmitted Infection ◽

Sexually Transmitted ◽

Ct Value

ABSTRACTAs WHO reported, four curable STIs-chlamydia, gonorrhoea, syphilis and trichomoniasis occur more than 1 million per each day globally almond 2016. For this reason, it is important to control these STIs, one of which is “to detect”. The general methods in order to detect STIs are nucleic acid amplification tests (NAATs). One of the reasons why NAATs are utilized in many tests is that it is possibly to be more sensitive than other test. However, there needs to treat extraction of nucleic acids in advance and amplify specific regions by NAATs, and hence it must take much labour and much time. In this work, for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Treponema pallidum (TP) which is each etiological agent of chlamydia, gonorrhoea and syphilis, we evaluate and propose “quicker and simpler” NAATs. Specifically, utilizing mobile real-time PCR device “PCR1100” and PCR reagent kit “KAPA3G Plant PCR Kit”, it was considered whether real-time direct PCR could be performed or not without treating DNA extraction in advance so-called “direct”.As a result, firstly, we established that real-time direct PCR could be performed in all of CT, NG, and TP, and moreover, each Ct value correlated with the concentration of each organism similarly to detection of genome DNA (each correlation coefficient R2 > 0.95). Moreover, each assay demonstrated a limit of detection (LOD) of the follows; CT was 10^0.86 = 7.24 IFU/reaction, NG was 10^-0.19 = 0.65 CFU/reaction, and TP was 10^1.4 = 25.1 organisms/reaction. However, it appeared the sensitivity was a little low, especially for CT and TP.Secondly, we found that even as without treating sample in advance, the time of detection was required more less 15 minutes at any of case, which was very quick compared with other current methods for real-time PCR. Additionally, compared with other commercial devices, it was easier to operate the PCR1100 device, for example, start, analysis of Ct value.In conclusion, the present study has demonstrated that it is possible for real-time direct PCR to perform with combination of the PCR1100 device and the PCR reagent kit in 3 kinds of microorganisms-CT, NG and TP. Furthermore, we propose “quicker and simpler” methods for NAATs, which it would not take labour and time. Further studies are needed in order to contribute to control STIs.

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