Adequate knowledge and accurate characterization of root and canal anatomy is an essential prerequisite for successful root canal treatment and endodontic surgery. Over the years, an ever‐increasing body of knowledge related to root and canal anatomy of the human dentition has accumulated. To correct deficiencies in existing systems, a new coding system for classifying root and canal morphology, accessory canals and anomalies has been introduced. In recent years, micro‐computed tomography (micro‐CT) and cone beam computed tomography (CBCT) have been used extensively to study the details of root and canal anatomy in extracted teeth and within clinical settings. This review aims to discuss the application of the new coding system in studies using micro‐CT and CBCT, provide a detailed guide for appropriate characterization of root and canal anatomy and to discuss several controversial issues that may appear as potential limitations for proper characterization of roots and canals.

Introduction. Modern radiation therapy has become an effective method to treat and monitor tumour growth in cancer patients. It has proved to be a successful way to minimise mortality rates. However, the adverse effects of radiation have been historical evidence in the clinical environment involving diminishing the quality and density of bone and causing fragility fracture to the bone in the long run. This systematic review was aimed at identifying and evaluating the effects of irradiation on morphology and mechanical properties of murine model bone in previous publications. Methods. A systematic literature review was undertaken following the Preferred Reporting Items for Systemic Reviews and Meta-analysis (PRISMA) guidelines. A comprehensive literature search was performed using Scopus, Web of Science, and Science Direct databases (English only studies published between 2015 and 2020). The selected studies were evaluated according to three criteria: (1) criteria for study sample selection; (2) criteria for methodological procedures; and (3) criteria for detection and evaluation. Results. The initial search strategy identified 1408 related studies, 8 of were included based on inclusion and exclusion criteria. This review revealed an association between bone destruction and the magnitude of time and dose postirradiation. We agreed that the effect of radiation on bone morphology and strength primarily is a later stage event but noticeable in both low (1 Gy) and high dose (30 Gy) radiation. Trabecular and cortical bone microstructures were significantly altered at irradiation and contralateral sites. Besides, the mechanical strength was significantly impacted in both shorter and longer periods. Conclusion. Overall, the radiotherapy altered bone microstructures and substantially decreases bone mechanical properties. The alteration was related to quantity and the activity of the osteoblast and osteoclast. Early detection of those most at risk for radiation-induced bone alterations could lead to better prophylactic intervention decisions.

Piper betle leaves are widely cultivated in Malaysia, India, Indonesia and Thailand. They have been used as a traditional medicine for centuries due to their medicinal properties, including antioxidant, antiproliferative, antibacterial, antifungal and anti-inflammatory properties, which are attributable to their high phenolic contents. Hydroxychavicol (HC), a primary constituent of P. betle leaves, is known to possess antiproliferative activity at micromolar doses on various cancer cell lines of different origins while leaving normal cells unharmed. The present review summarises the mechanisms of action of HC reported in the literature, reviews the scope of work done thus far and outlines the direction of future research on the potential of HC as an anticancer agent. PubMed, Scopus and Web of Science were searched using the keywords (hydroxychavicol OR 4-allylpyrocatechol OR 4-allylcatechol) AND (cancer OR carcinogenesis OR tumour OR carcinoma) to acquire research articles. In vitro studies reported several possible mechanisms for the chemopreventive effects of HC against cancer cell lines, including chronic myelogenous leukaemia (CML), prostate, glioma, breast and colorectal cancers, while in vivo studies encompassed investigations on Ehrlich ascites carcinoma cells in Swiss albino mice and a CML mouse model. These studies suggest that HC exerts its anticancer effect via the modulation of mitochondrial membrane potential and the c-Jun N-terminal kinase, mitogen-activated protein kinase and endoplasmic reticulum-unfolded protein responses pathways and the generation of reactive oxygen species. In summary, future research should focus on combinations of HC with other anticancer drugs and testing in animal models to evaluate its bioavailability, potency and tissue and dose selectivity. Contents 1. Introduction 2. Methods 3. Composition of HC 4. In vitro and in vivo studies 5. Anti-inflammatory activity of HC 6. Conclusions and prospects

Background: The current clinical practice to manage kidney stone requires knowledge of the stone composition. However, it is often difficult to determine the actual stone composition before a stone is operatively removed from the patient. Dual-energy computed tomography (DECT) can predict urinary stone composition, but it is not widely adopted. The purpose of the study was to investigate the use of a second-generation DECT with tin or stannum (Sn) filter for characterising the kidney stones composition. Methods: Thirty-three kidney stones were scanned ex vivo using a dual-source (DS)DECT scanner with dual-energy (DE) mode of 80/140 kVp with and without 4 mm Sn filtration. DE ratio was calculated to determine the kidney stones composition (uric acid, calcium oxalate, calcium phosphate and cystine). The median DE ratio of the stones was compared using Wilcoxon signed rank test and the results were further correlated with semi-quantitative Fourier transform infrared (FTIR) spectroscopy analysis using Kendall’s Tau test with P < 0.05 deemed to be statistically significant. Results: Second-generation DS-DECT could significantly discriminate the stones composition with and without Sn filtration (P < 0.001). The median DE ratio of uric acid, calcium oxalate and cystine stones were significantly higher with Sn filtration than those without filtration (P < 0.05). DECT results revealed significant correlation with FTIR spectroscopy analysis (r = 0.716, P < 0.001). DECT with Sn filtration showed increased performance (100% sensitivity, 0% specificity) than those without filtration (48.5% sensitivity, 0% specificity) in the detection of the kidney stone subtypes. Conclusion: In the second-generation DECT with additional Sn filtration, DECT has shown a significant performance in characterising and discriminating the kidney stone composition. This may improve diagnostic and therapy management in kidney stones cases.

Introduction: Hybrid Positron Emission Tomography with Computed Tomography (PET/CT) imaging is well established in the oncology setting. However, in the current cancer diagnostic imaging approach in Malaysia patients need separate CT and PET/CT examinations for morphologic and physiologic cancer staging, respectively, as PET/CT is unable to produce images with optimum diagnostic quality. Therefore, introducing contrast media into CT attenuation correction (CTAC) acquisition to increase image quality have raised concerns on heightened radiation exposure. This study aimed to verify the amount of external radiation exposure irradiated to the patient converging to the scanning protocol implemented in whole-body (WB) 18F-FDG-PET/CT examination. Methods: A retrospective study was conducted to determine the radiation dose delivered during CTAC acquisition of 18F-FDG-PET/CT examination at three hospitals providing PET/CT imaging services in Penang State. The implemented scanning protocols and parameters, and the effective dose received by the patient were analysed based on dose length product (DLP) and CTDIvol reported by the scanner. Results: CTAC of WB 18F-FDG-PET/CT imaging was executed as either non-contrast (NC-CTAC) or contrast-enhanced (CE-CTAC). CE-CTAC produced a 250% higher radiation dose compared to NC-CTAC. The scanning parameter differences that significantly contributed to increased radiation dose were the tube current and pitch value. Conclusion: CE-CTAC delivered a higher radiation dose than NC-CTAC acquisition in WB 18F-FDG PET/CT imaging due to different mAs and pitch as scanning parameters. Malaysian Journal of Medicine and Health Sciences (2022) 18(SUPP15): 132-139. doi:10.478

Introduction: The aim of this study is to applied CT scan-based tissue segmentation to measure visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) volumes. Then, the ratio of both fat tissue volumes was calculated to get two more parameters: visceral fat volume ratio (VFVR) and subcutaneous fat volume ratio (SFVR). After that, the relationship between these factors and urolithiasis recurrence was examined using correlation analysis. Other parameters, which are the patient’s age and gender, were also tested for correlation analysis with urolithiasis recurrence. Finally, logistic regression analysis was performed to find the association between urolithiasis recurrence and the parameters (age, gender, VAT volume, SAT volume, VFVR and SFVR). Methods: This study was a retrospective cross-sectional study design using the images collected from CT Urology cases in the year 2019. The patients selected have a history of stone removal in 2014. The application used for CT tissue segmentation is 3D Slicer. Results: Urolithiasis recurrence shows medium and high degree of positive correlation with total fat volume, VAT volume, and VFVR (correlation coefficient, cc = 0.254, p = 0.023), (cc = 0.390, p< 0.001) and (cc = 0.688, p< 0.001), respectively and high degree of negative correlation with SFVR (cc = -0.688, p< 0.001). However, using logistic regression analysis, only VAT volume was significantly associated with urolithiasis recurrence (OR 1.11, 95% CI 1.01-1.22, p= 0.03), while the total fat volume, VFVR, and SFVR are not significant. Conclusion: CT scan-based tissue segmentation has a huge impact on fat volume quantification. This study confirms that VAT volume was strongly correlated with urolithiasis recurrence, indicating that VAT volume plays a more important role than SAT volume, total fat volume, VFVR and SFVR in the production of urinary stone. Thus, VAT volume can be further considered as a new independent risk factor for urolithiasis.

This study aims to evaluate the impact of clinicopathological factors on metabolic parameters of 18F-FDG PET/CT in the different staging of breast cancer. 15 histopathologically confirmed breast cancer lesions on patients who underwent whole- body FDG-PET/CT for staging were retrospectively reviewed. Three PET/CT metabolic parameters including semiquantitative maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were quantified over the primary lesions of the breast. The parameters were statistically correlated with clinicopathological factors including patients’ age, body mass index (BMI) and tumour size. Multivariate regression was performed to determine the significant factors that best predicted those metabolic parameters. Tumour size was significantly correlated to all metabolic parameters (p < 0.001) and was a significant predictor of those parameters (p < 0.001). Tumour size accounted for 77.5%, 94.3% and 96.2% of the SUVmax, MTV and TLG variances, respectively. Tumour size significantly affects the metabolic parameters of 18F-FDG PET/CT (SUVmax, MTV and TLG) in the staging of breast cancer. Therefore, tumour size has a prognostic value for the staging of breast cancer in a 18F-FDG PET/CT study for improved clinical management.