[Reflections on good manufacturing practice and quality control system of personalized traditional Chinese medicine preparations].

Personalized traditional Chinese medicine(TCM) preparations have entered a stage of rapid development. The key to the healthy development of this industry is to establish a sound manufacturing standard and quality control system. This paper analyzed the characteristics of personalized TCM preparations and drew reference from the quality management standards in the production of commissioned decoctions and oral pastes, on the basis of which the production quality management scheme and cautions for the safe production of personalized TCM preparations was put forward with consideration to various problems that may exist and occur in the production of such preparations. It provided references for formulating the production standards and quality management system of personalized TCM preparations. The production standards and quality control system should develop with the times. In the future, modern technologies such as big data and artificial intelligence should be employed to achieve the automated and intelligent production and establish a sound quality traceability system, online control strategy, and safety management mode of personalized TCM preparations, which will ensure the healthy development of this industry under requirement of good manufacturing practice(GMP).

[Research practice and development direction of intelligent manufacturing of presonalized traditional Chinese medicine preparations].

In recent years, as people's living standards continue to improve, and the pace of life accelerates dramatically, the demand and quality of traditional Chinese medicine(TCM) services from patients continue to rise. As an essential supplement to the existing forms of TCM application, such as Chinese patent medicine, decoction, and formulated granules, presonalized TCM preparations is facing an increasing market demand. Currently, manual and semi-mechanized production are the primary production ways in presonalized TCM preparations. However, the production process control level is low, and digitalization and informatization need to be improved, which restricts the automated and intelligent development of presonalized TCM preparations. Presonalized TCM preparations faces a significant opportunity and challenge in integrating with intelligent manufacturing through research and development of intelligent equipment and core technology. This paper overviews the connotation and characteristics of intelligent manufacturing and summarizes the application of intelligent manufacturing technologies such as "Internet of things" "big data", and "artificial intelligence" in the TCM industry. Based on the innovative research and development model of "intelligent classification of TCM materials, intelligent decision making of prescription and process, and online control and intelligent production" of presonalized TCM preparations, the research practice and achievements from our research group in the field of intelligent manufacturing of presonalized TCM preparations are introduced. Ultimately, the paper proposes the direction for developing intelligent manufacturing of presonalized TCM preparations, which will provide a reference for the research and application of automation and intelligence of presonalized TCM preparations.

[Application and development of electronic sensing technologies represented by electronic nose in modern traditional Chinese medicine preparations].

Odor is one of the important indicators evaluating the quality of traditional Chinese medicines. Research data has shown that there are increasing methods available for evaluating the odors of traditional Chinese medicines. Compared with conventional odor sensing techniques, electronic noses stand out for their convenience, high speed, and objectivity. The progress in the pharmaceutical technology of traditional Chinese medicines has provided new formulas and dosage forms for the innovative development in this field. The electronic nose with versatility can be customized to be equipped with a variety of cross-sensors, which can well satisfy the needs of the traditional Chinese medicine preparation technology. This study summarizes the characteristics, application status, and representative products of the current electronic nose, and analyzes the application and feasibility of electronic nose in the production of traditional Chinese medicine preparations based on the current status of odor evaluation. This review is expected to provide new methods, techno-logies, and ideas for electronic nose to play its unique role in the whole-process quality control and pharmaceutical process of traditional Chinese medicine preparations.

[Critical influencing factors on quality of traditional Chinese medicine preparations from perspective of process and equipment].

The quality of traditional Chinese medicine preparations is directly related to the safety of patients. Among the various factors, the process and corresponding critical equipment are critical factors influencing the quality of the preparations. To improve the quality of traditional Chinese medicine preparations, this article summarizes and analyzes the problems in the process links and corresponding critical equipment in the manufacturing process of traditional Chinese medicine preparations. Furthermore, a critical quality attribute evaluation system is established based on safety and effectiveness combined with the drug properties, preparation process, and preparation characteristics, providing a basis for the process and equipment improvements aimed at quality enhancement.

[Quality control of Tianwang Buxin Pills based on UPLC fingerprint and multi-component quantification].

Tianwang Buxin Pills have demonstrated therapeutic effects in clinical practice, whereas there is a serious lack of comprehensive quality control to ensure the safety and effectiveness of clinical medication. In this study, ultra-performance liquid chromatography(UPLC) was employed to establish the fingerprint and the method for simultaneously determining the content of seven components of Tianwang Buxin Pills. Furthermore, chemometrics was employed to identify the key factors for the stable quality, which provided a reference for the comprehensive quality control and evaluation of this preparation. There were 25 common peaks in the UPLC fingerprints of 15 batches of Tianwang Buxin Pills, from which thirteen compounds were identified. A quantitation method was established for seven pharmacological components(α-linolenic acid, salvianolic acid B, glycyrrhetinic acid, schisandrin A, ß-asarone, 3,6'-disinapoylsucrose, and ligustilide). The principal component analysis(PCA) and partial least square discriminate analysis(PLS-DA) were performed to determine the key pharmacological components for controlling the quality stability of Tianwang Buxin Pills, which included 3,6'-disinapoylsucrose, α-linolenic acid, and ß-asarone. The established fingerprint and multi-component content determination method have strong specificity, stability, and reliability. In addition, 3,6'-disinapoylsucrose, α-linolenic acid, and ß-asarone are the key pharmacological components that ensure the quality stability between batches and can be used to comprehensively control the quality of Tianwang Buxin Pills. The findings provide a scientific basis for the quality evaluation and standard establishment of Tianwang Buxin Pills.

Result of a Pilot External Quality Assessment Scheme for Clinical Diagnosis of Inherited Metabolic Disorders in China.

BACKGROUND: We aimed to evaluate the diagnostic capabilities of Chinese laboratories for inherited metabolic disorders (IMDs) using gas chromatography-mass spectrometry (GC-MS) on urine samples. Meanwhile, based on the result of the pilot external quality assessment (EQA) scheme, we hope to establish a standardized and reliable procedure for future EQA practice. METHODS: We recruited laboratories that participated in the EQA of quantitative analysis of urinary organic acids with GC-MS before joining the surveys. In each survey, a set of five real urine samples was distributed to each participant. The participants should analyze the sample by GC-MS and report the "analytical result", "the most likely diagnosis", and "recommendation for further tests" to the NCCL before the deadline. RESULTS: A total of 21 laboratories participated in the scheme. The pass rates were 94.4% in 2020 and 89.5% in 2021. For all eight IMDs tested, the analytical proficiency rates ranged from 84.7% - 100%, and the interpretational performance rate ranged from 88.2% - 97.0%. The performance on hyperphenylalaninemia (HPA), 3-methylcrotonyl-CoA carboxylase deficiency (MCCD), and ethylmalonic encephalopathy (EE) samples were not satisfactory. CONCLUSIONS: In general, the participants of this pilot EQA scheme are equipped with the basic capability for qualitative organic acid analysis and interpretation of the results. Limited by the small size of laboratories and samples involved, this activity could not fully reflect the state of clinical practice of Chinese laboratories. NCCL will improve the EQA scheme and implement more EQA activities in the future.

Analysis of Imprecision for Internal Quality Control of Newborn Screening by Tandem Mass Spectrometry in China, 2015 - 2021.

BACKGROUND: This study aimed to assess the performance of the newborn screening laboratories in China through retrospective analysis of the coefficient of variation (CV) of the internal quality control (IQC) data in the national tandem mass spectrometry screening for inherited metabolic disorders in newborns. METHODS: From 2015 to 2021, the IQC data of amino acid and acylcarnitine test were collected twice each year. CVmonthly in-control was calculated by excluding outliers for the current month and its discrete distribution and changes in trend were comprehensively evaluated for both normal and high concentration levels. The proportion of laboratories meeting both 1/3 and 1/4 quality criteria of the total error allowable (TEa), based on the CVmonthly in-control for each testing item, was calculated. RESULTS: The analysis of CVmonthly in-control for the two concentration levels for the amino acids and acylcarnitine parameters showed that CVmonthly in-control for the normal concentration levels were more discrete before 2018, while CVmonthly in-control for the high concentration levels were less discrete than the normal concentration levels, but there were relatively more outliers. More than 80% of laboratories were able to meet the 1/3 TEa standard for each test at the high concentration level, while the pass rate for the 1/4 TEa standard was significantly lower than 80% (except for C2). CONCLUSIONS: According to the current status of testing in China, it is recommended to use 1/3TEa as the imprecision level standard; for laboratories with relatively high precision, the 1/4TEa standard can be used.

Recent Advances and Future Perspectives in the E-Nose Technologies Addressed to the Wine Industry.

Electronic nose devices stand out as pioneering innovations in contemporary technological research, addressing the arduous challenge of replicating the complex sense of smell found in humans. Currently, sensor instruments find application in a variety of fields, including environmental, (bio)medical, food, pharmaceutical, and materials production. Particularly the latter, has seen a significant increase in the adoption of technological tools to assess food quality, gradually supplanting human panelists and thus reshaping the entire quality control paradigm in the sector. This process is happening even more rapidly in the world of wine, where olfactory sensory analysis has always played a central role in attributing certain qualities to a wine. In this review, conducted using sources such as PubMed, Science Direct, and Web of Science, we examined papers published between January 2015 and January 2024. The aim was to explore prevailing trends in the use of human panels and sensory tools (such as the E-nose) in the wine industry. The focus was on the evaluation of wine quality attributes by paying specific attention to geographical origin, sensory defects, and monitoring of production trends. Analyzed results show that the application of E-nose-type sensors performs satisfactorily in that trajectory. Nevertheless, the integration of this type of analysis with more classical methods, such as the trained sensory panel test and with the application of destructive instrument volatile compound (VOC) detection (e.g., gas chromatography), still seems necessary to better explore and investigate the aromatic characteristics of wines.

Generating Homogeneous Brain Organoids from Human iPSCs.

There is a high demand for the development of in vitro models for human brain development and diseases due to the inaccessibility of human brain tissues. The human iPSC-derived brain organoids provide a promising in vitro model for studying human brain development and disorders. However, it is challenging to generate a large number of brain organoids with high consistency for modeling human neurological diseases. Here, we describe a method for generating high-yield brain organoids with high consistency by combining large-scale embryoid body (EB) generation and incorporating a quality control screening step during differentiation. The method described in this chapter provides a robust way to generate brain organoids for studying human brain development and modeling neurological diseases.

A Highly Sensitive and Rapid Colloidal Gold Immunoassay for Puerarin Detection.

Radix Puerariae is a traditional Chinese medicinal material with a rich history of use in East and Southeast Asia. Puerarin, a unique component of the Pueraria genus, serves as a quality control marker for herbal medicines like Pueraria lobata and Pueraria thomsonii in China, displaying diverse pharmacological properties. This study developed puerarin colloidal gold immunoassay dipsticks utilizing an anti-puerarin monoclonal antibody, resulting in a fast and sensitive detection method with a limit of 500-1000 ng·mL-1. Evaluation using tap water-extracted P. lobata and P. thomsonii samples showed consistent results compared to LC-MS analysis. Cross-reactivity assessments of puerarin analogs revealed minimal interference, affirming the dipstick's reliability for distinguishing between the two species.

Application of quality control circle in the management of early ambulation after cesarean section: An observational study.

BACKGROUND: The quality control circle (QCC) model has achieved good results in clinical applications in many hospitals in China and has gained popularity. This study aims to explore the application of QCC activities on early ambulation after cesarean section. METHODS: A QCC management group was established following standardized methods and techniques. The theme of the group was identified as "to enhance the implementation rate of the patient early ambulation after the cesarean section" through a matrix graph. The early ambulation rates after surgery of patients who received cesarean section were compared before and after QCC managements. RESULTS: Our data suggested that the early ambulation rates after cesarean section increased from 37.5% to 81.25% after applying QCC management. The biggest factor influencing the ambulation activities 24 ±â€…4 hours after the surgery was patients and family members do not cooperate. In addition, outstanding improvements in terms of nurses' sense of responsibility and self-confidence, communication and teamwork capacity in the problem-solving process were observed after the establishment of QCC. CONCLUSION: The application of QCC management had not only increase the early ambulation rates after cesarean section but also improved the quality of nursery care in general.

Biosensing-based quality control monitoring of the higher-order structures of therapeutic antibody domains.

Advanced biopharmaceutical manufacturing requires novel process analytical technologies for the rapid and sensitive assessment of the higher-order structures of therapeutic proteins. However, conventional physicochemical analyses of denatured proteins have limitations in terms of sensitivity, throughput, analytical resolution, and real-time monitoring capacity. Although probe-based sensing can overcome these limitations, typical non-specific probes lack analytical resolution and provide little to no information regarding which parts of the protein structure have been collapsed. To meet these analytical demands, we generated biosensing probes derived from artificial proteins that could specifically recognize the higher-order structural changes in antibodies at the protein domain level. Biopanning of phage-displayed protein libraries generated artificial proteins that bound to a denatured antibody domain, but not its natively folded structure, with nanomolar affinity. The protein probes not only recognized the higher-order structural changes in intact IgGs but also distinguished between the denatured antibody domains. These domain-specific probes were used to generate response contour plots to visualize the antibody denaturation caused by various process parameters, such as pH, temperature, and holding time for acid elution and virus inactivation. These protein probes can be combined with established analytical techniques, such as surface plasmon resonance for real-time monitoring or plate-based assays for high-throughput analysis, to aid in the development of new analytical technologies for the process optimization and monitoring of antibody manufacturing.

SEAOP: a statistical ensemble approach for outlier detection in quantitative proteomics data.

Quality control in quantitative proteomics is a persistent challenge, particularly in identifying and managing outliers. Unsupervised learning models, which rely on data structure rather than predefined labels, offer potential solutions. However, without clear labels, their effectiveness might be compromised. Single models are susceptible to the randomness of parameters and initialization, which can result in a high rate of false positives. Ensemble models, on the other hand, have shown capabilities in effectively mitigating the impacts of such randomness and assisting in accurately detecting true outliers. Therefore, we introduced SEAOP, a Python toolbox that utilizes an ensemble mechanism by integrating multi-round data management and a statistics-based decision pipeline with multiple models. Specifically, SEAOP uses multi-round resampling to create diverse sub-data spaces and employs outlier detection methods to identify candidate outliers in each space. Candidates are then aggregated as confirmed outliers via a chi-square test, adhering to a 95% confidence level, to ensure the precision of the unsupervised approaches. Additionally, SEAOP introduces a visualization strategy, specifically designed to intuitively and effectively display the distribution of both outlier and non-outlier samples. Optimal hyperparameter models of SEAOP for outlier detection were identified by using a gradient-simulated standard dataset and Mann-Kendall trend test. The performance of the SEAOP toolbox was evaluated using three experimental datasets, confirming its reliability and accuracy in handling quantitative proteomics.

IMPATIENT-qPCR: monitoring SELEX success during in vitro aptamer evolution.

SELEX (Systematic Evolution of Ligands by Exponential enrichment) processes aim on the evolution of high-affinity aptamers as binding entities in diagnostics and biosensing. Aptamers can represent game-changers as constituents of diagnostic assays for the management of instantly occurring infectious diseases or other health threats. Without in-process quality control measures SELEX suffers from low overall success rates. We present a quantitative PCR method for fast and easy quantification of aptamers bound to their targets. Simultaneous determination of melting temperatures (Tm) of each SELEX round delivers information on the evolutionary success via the correlation of increasing GC content and Tm alone with a round-wise increase of aptamer affinity to the respective target. Based on nine successful and published previous SELEX processes, in which the evolution/selection of aptamer affinity/specificity was demonstrated, we here show the functionality of the IMPATIENT-qPCR for polyclonal aptamer libraries and resulting individual aptamers. Based on the ease of this new evolution quality control, we hope to introduce it as a valuable tool to accelerate SELEX processes in general. IMPATIENT-qPCR SELEX success monitoring. Selection and evolution of high-affinity aptamers using SELEX technology with direct aptamer evolution monitoring using melting curve shifting analyses to higher Tm by quantitative PCR with fluorescence dye SYBR Green I. KEY POINTS: • Fast and easy analysis. • Universal applicability shown for a series of real successful projects.

Manufacturing, quality control, and GLP-grade preclinical study of nebulized allogenic adipose mesenchymal stromal cells-derived extracellular vesicles.

BACKGROUND: Human adipose stromal cells-derived extracellular vesicles (haMSC-EVs) have been shown to alleviate inflammation in acute lung injury (ALI) animal models. However, there are few systemic studies on clinical-grade haMSC-EVs. Our study aimed to investigate the manufacturing, quality control (QC) and preclinical safety of clinical-grade haMSC-EVs. METHODS: haMSC-EVs were isolated from the conditioned medium of human adipose MSCs incubated in 2D containers. Purification was performed by PEG precipitation and differential centrifugation. Characterizations were conducted by nanoparticle tracking analysis, transmission electron microscopy (TEM), Western blotting, nanoflow cytometry analysis, and the TNF-α inhibition ratio of macrophage [after stimulated by lipopolysaccharide (LPS)]. RNA-seq and proteomic analysis with liquid chromatography tandem mass spectrometry (LC-MS/MS) were used to inspect the lot-to-lot consistency of the EV products. Repeated toxicity was evaluated in rats after administration using trace liquid endotracheal nebulizers for 28 days, and respiratory toxicity was evaluated 24 h after the first administration. In vivo therapeutic effects were assessed in an LPS-induced ALI/ acute respiratory distress syndrome (ARDS) rat model. RESULTS: The quality criteria have been standardized. In a stability study, haMSC-EVs were found to remain stable after 6 months of storage at - 80°C, 3 months at - 20 °C, and 6 h at room temperature. The microRNA profile and proteome of haMSC-EVs demonstrated suitable lot-to-lot consistency, further suggesting the stability of the production processes. Intratracheally administered 1.5 × 108 particles/rat/day for four weeks elicited no significant toxicity in rats. In LPS-induced ALI/ARDS model rats, intratracheally administered haMSC-EVs alleviated lung injury, possibly by reducing the serum level of inflammatory factors. CONCLUSION: haMSC-EVs, as an off-shelf drug, have suitable stability and lot-to-lot consistency. Intratracheally administered haMSC-EVs demonstrated excellent safety at the tested dosages in systematic preclinical toxicity studies. Intratracheally administered haMSC-EVs improved the lung function and exerted anti-inflammatory effects on LPS-induced ALI/ARDS model rats.

A comprehensive performance evaluation, comparison, and integration of computational methods for detecting and estimating cross-contamination of human samples in cancer next-generation sequencing analysis.

Cross-sample contamination is one of the major issues in next-generation sequencing (NGS)-based molecular assays. This type of contamination, even at very low levels, can significantly impact the results of an analysis, especially in the detection of somatic alterations in tumor samples. Several contamination identification tools have been developed and implemented as a crucial quality-control step in the routine NGS bioinformatic pipeline. However, no study has been published to comprehensively and systematically investigate, evaluate, and compare these computational methods in the cancer NGS analysis. In this study, we comprehensively investigated nine state-of-the-art computational methods for detecting cross-sample contamination. To explore their application in cancer NGS analysis, we further compared the performance of five representative tools by qualitative and quantitative analyses using in silico and simulated experimental NGS data. The results showed that Conpair achieved the best performance for identifying contamination and predicting the level of contamination in solid tumors NGS analysis. Moreover, based on Conpair, we developed a Python script, Contamination Source Predictor (ConSPr), to identify the source of contamination. We anticipate that this comprehensive survey and the proposed tool for predicting the source of contamination will assist researchers in selecting appropriate cross-contamination detection tools in cancer NGS analysis and inspire the development of computational methods for detecting sample cross-contamination and identifying its source in the future.

Force-induced tail-autotomy mitochondrial fission and biogenesis of matrix-excluded mitochondrial-derived vesicles for quality control.

Mitochondria constantly fuse and divide for mitochondrial inheritance and functions. Here, we identified a distinct type of naturally occurring fission, tail-autotomy fission, wherein a tail-like thin tubule protrudes from the mitochondrial body and disconnects, resembling autotomy. Next, utilizing an optogenetic mitochondria-specific mechanostimulator, we revealed that mechanical tensile force drives tail-autotomy fission. This force-induced fission involves DRP1/MFF and endoplasmic reticulum tubule wrapping. It redistributes mitochondrial DNA, producing mitochondrial fragments with or without mitochondrial DNA for different fates. Moreover, tensile force can decouple outer and inner mitochondrial membranes, pulling out matrix-excluded tubule segments. Subsequent tail-autotomy fission separates the matrix-excluded tubule segments into matrix-excluded mitochondrial-derived vesicles (MDVs) which recruit Parkin and LC3B, indicating the unique role of tail-autotomy fission in segregating only outer membrane components for mitophagy. Sustained force promotes fission and MDV biogenesis more effectively than transient one. Our results uncover a mechanistically and functionally distinct type of fission and unveil the role of tensile forces in modulating fission and MDV biogenesis for quality control, underscoring the heterogeneity of fission and mechanoregulation of mitochondrial dynamics.

Establishment of a multi-strategy platform for quality control and quality markers screen of Mailuoshutong pill.

Thromboangiitis obliterans (TAO) is a non-atherosclerotic segmental inflammatory occlusive disease with a high recurrence rate, high disability rate, difficulty to cure, and poor prognosis. It has been clinically proven that Mailuoshutong pill (MLSTP) is an effective traditional Chinese medicine for treating TAO. As MLSTP contains hundreds of chemical components, the quality control of which is a challenge in the development of reliable quality evaluation metrics. This study aimed to evaluate the quality uniformity of MLSTP by establishing a multi-strategy platform. In the present study, the key targets and signaling pathways of MLSTP treating TAO were predicted by network pharmacology. It was further shown by in vivo validation experiments that MLSTP exerted therapeutic effects on TAO by modulating the PI3K-AKT signaling pathway, VEGF signaling pathway, and HIF-1 signaling pathway. In addition, UPLC fingerprints of MLSTP were established and screened for potential Q-markers of MLSTP in combination with network pharmacology results. Six components, including chlorogenic acid, liquiritin, paeoniflorin, calycosin-7-glucoside, berberine, and formononetin, were selected as potential quality markers (Q-markers) in MLSTP. Finally, the quantitative analysis of multi-components by single marker (QAMS) method was established to quantitatively analyze the six potential Q-markers, and the results were consistent with those obtained by the external standard method (ESM). Taken together, the multi-strategy platform established in this study would be conducive to the Q-markers screening and quality control of MLSTP, improving the quality standard of MLSTP and providing favorable assurance for the clinical management of TAO.

High throughput AS LNA qPCR method for the detection of a specific mutation in poliovirus vaccine strains.

Sabin Inactivated Poliovirus Vaccine (sIPV) has become one of the preferred vaccination options for the last step in the Poliovirus eradication program. Sequencing of poliovirus samples is needed during the manufacturing of poliovirus vaccines to assure the safety and immunogenicity of these vaccines. Next-generation sequencing analysis is the current costly and time-consuming gold standard for monitoring the manufacturing processes. We developed a low-cost and quick, highly sensitive, and allele-specific locked nucleic acid-probe-based reverse transcription quantitative PCR alternative that can accurately detect mutations in poliovirus vaccine samples during process development, scaling up, and release. Using the frequently in vitro occurring and viral replication-impacting VP1-E295K mutation as a showcase, we show that this technology can accurately detect E295K mutations in poliovirus 2 samples to similar levels as NGS. The qPCR technology was developed employing a synthetic dsDNA fragment-based standard curve containing mixes of E295K-WT (wildtype) and Mut (mutant) synthetic dsDNA fragments ranging from 1 × 107 copies/µL to 1 × 102 copies/µL to achieve a linear correlation with R2 > 0.999, and PCR efficiencies of 95-105 %. Individual standard concentration levels achieved accuracies of ≥92 % (average 96 %) and precisions of ≤17 % (average 3.3 %) RSD. Specificity of locked nucleic acid (LNA)-probes was confirmed in the presence and absence of co-mutations in the probe-binding region. Application of the developed assay to Sabin Poliovirus type 2 production run samples, illustrated a linear relationship with an R2 of 0.994, and an average accuracy of 97.2 % of the variant (allele)-specific AS LNA qPCR result, compared to NGS. The assay showed good sensitivity for poliovirus samples, containing E295K mutation levels between 0 % and 95 % (quantification range). In conclusion, the developed AS LNA qPCR presents a valuable low-cost, and fast tool, suitable for the process development and quality control of polio vaccines.

An automated technique for global noise level measurement in CT image with a conjunction of image gradient.

Automated assessment of noise level in clinical computed tomography (CT) images is a crucial technique for evaluating and ensuring the quality of these images. There are various factors that can impact CT image noise, such as statistical noise, electronic noise, structure noise, texture noise, artifact noise, etc. In this study, a method was developed to measure the global noise index (GNI) in clinical CT scans due to the fluctuation of x-ray quanta. Initially, a noise map is generated by sliding a 10 × 10 pixel for calculating Hounsfield unit (HU) standard deviation and the noise map is further combined with the gradient magnitude map. By employing Boolean operation, pixels with high gradients are excluded from the noise histogram generated with the noise map. By comparing the shape of the noise histogram from this method with Christianson's tissue-type global noise measurement algorithm, it was observed that the noise histogram computed in anthropomorphic phantoms had a similar shape with a close GNI value. In patient CT images, excluding the HU deviation due the structure change demonstrated to have consistent GNI values across the entire CT scan range with high heterogeneous tissue compared to the GNI values using Christianson's tissue-type method. The proposed GNI was evaluated in phantom scans and was found to be capable of comparing scan protocols between different scanners. The variation of GNI when using different reconstruction kernels in clinical CT images demonstrated a similar relationship between noise level and kernel sharpness as observed in uniform phantom: sharper kernel resulted in noisier images. This indicated that GNI was a suitable index for estimating the noise level in clinical CT images with either a smooth or grainy appearance. The study's results suggested that the algorithm can be effectively utilized to screen the noise level for a better CT image quality control.