Automatic slice thickness measurement on three types of Catphan CT phantoms.

Objective. To develop an algorithm to measure slice thickness running on three types of Catphan phantoms with the ability to adapt to any misalignment and rotation of the phantoms.Method. Images of Catphan 500, 504, and 604 phantoms were examined. In addition, images with various slice thicknesses ranging from 1.5 to 10.0 mm, distance to the iso-center and phantom rotations were also examined. The automatic slice thickness algorithm was carried out by processing only objects within a circle having a diameter of half the diameter of the phantom. A segmentation was performed within an inner circle with dynamic thresholds to produce binary images with wire and bead objects within it. Region properties were used to distinguish wire ramps and bead objects. At each identified wire ramp, the angle was detected using the Hough transform. Profile lines were then placed on each ramp based on the centroid coordinates and detected angles, and the full-width at half maximum (FWHM) was determined for the average profile. The slice thickness was obtained by multiplying the FWHM by the tangent of the ramp angle (23°).Results. Automatic measurements work well and have only a small difference (<0.5 mm) from manual measurements. For slice thickness variation, automatic measurement successfully performs segmentation and correctly locates the profile line on all wire ramps. The results show measured slice thicknesses that are close (<3 mm) to the nominal thickness at thin slices, but slightly deviated for thicker slices. There is a strong correlation (R2= 0.873) between automatic and manual measurements. Testing the algorithm at various distances from the iso-center and phantom rotation angle also produced accurate results.Conclusion. An automated algorithm for measuring slice thickness on three types of Catphan CT phantom images has been developed. The algorithm works well on various thicknesses, distances from the iso-center, and phantom rotations.

Trends in Vaccination Refusal in Children Under 2 Years of Age in Kedah, Malaysia: A 4-Year Review From 2013 to 2016.

The current study examined how the trends in childhood vaccination refusal in Kedah, Malaysia, changed over a 4-year period (2013-2016). Data contributed by 60 public health centers were used to determine the annual incidence rates (per 1000 newborns) of vaccination refusal, and to identify the reasons for refusal among the mothers. The trend analysis revealed a 2.2-times increment in the incidence rates of vaccination refusal from 4.72 in 2013 to 10.51 in 2015, followed by a 52.2% reduction to 5.02 in 2016 ( P = .046). Besides, the proportion of mothers who refused vaccination because of religious belief reduced from 78% between 2013 and 2015 to 67.1% in 2016 ( P = .005). Overall, the finding confirms the positive impact of the educational and religious interventions introduced by the State Health Department of Kedah since January 2016; nonetheless, efforts to strengthen the existing strategies and thereby to maximize the vaccination coverage in Kedah are warranted.

Survival Analysis and Prognostic Factors for Colorectal Cancer Patients in Malaysia.

BACKGROUND: Cancer survival analysis is an essential indicator for effective early detection and improvements in cancer treatment. This study was undertaken to document colorectal cancer survival and associated prognostic factors in Malaysians. MATERIALS AND METHODS: All data were retrieved from the National Cancer Patient Registry Colorectal Cancer. Only cases with confirmed diagnosis through histology between the year 2008 and 2009 were included. Retrieved data include sociodemographic information, pathological features and treatment received. Survival curves were plotted using the KaplanMeier method. Univariate analysis of all variables was then made using the Logrank test. All significant factors that influenced survival of patients were further analysed in a multivariate analysis using Cox' regression. RESULTS: Total of 1,214 patients were included in the study. The overall 3 and 5year survival rates were 59.1% and 48.7%, respectively. Patients with localized tumours had better prognosis compared to those with advanced stage cancer. In univariate analysis, staging at diagnosis (p<0.001), primary tumour size (p<0.001), involvement of lymph nodes (p<0.001) and treatment modalities (p=0.001) were found to be predictors of survival. None of the sociodemographic characteristics were found to exert any influence. In Cox regression analysis, staging at diagnosis (p<0.001), primary tumour size (p<0.001), involvement of lymph nodes (p<0.001) and treatment modalities (p<0.001) were determined as independent prognostic factors of survival after adjusted for age, gender and ethnicity. CONCLUSIONS: The overall survival rate for colorectal cancer patients in Malaysia is similar to those in other Asian countries, with staging at diagnosis, primary tumor size, involvement of lymph node and treatment modalities having significant effects. More efforts are needed to improve national survival rates in future.

Incidence and mortality rates of colorectal cancer in Malaysia.

OBJECTIVES: This is the first study that estimates the incidence and mortality rate for colorectal cancer (CRC) patients in Malaysia by sex and ethnicity. METHODS: The 4,501 patients were selected from National Cancer Patient Registry-Colorectal Cancer data. Patient survival status was cross-checked with the National Registration Department. The age-standardised rate (ASR) was calculated as the proportion of CRC cases (incidence) and deaths (mortality) from 2008 to 2013, weighted by the age structure of the population, as determined by the Department of Statistics Malaysia and the World Health Organization world standard population distribution. RESULTS: The overall incidence rate for CRC was 21.32 cases per 100,000. Those of Chinese ethnicity had the highest CRC incidence (27.35), followed by the Malay (18.95), and Indian (17.55) ethnicities. The ASR incidence rate of CRC was 1.33 times higher among males than females (24.16 and 18.14 per 100,000, respectively). The 2011 (44.7%) CRC deaths were recorded. The overall ASR of mortality was 9.79 cases, with 11.85 among the Chinese, followed by 9.56 among the Malays and 7.08 among the Indians. The ASR of mortality was 1.42 times higher among males (11.46) than females (8.05). CONCLUSIONS: CRC incidence and mortality is higher in males than females. Individuals of Chinese ethnicity have the highest incidence of CRC, followed by the Malay and Indian ethnicities. The same trends were observed for the age-standardised mortality rate.