METHODS: The system typically consists of segmenting the calcium region from the CT scan into slices based on Hounsfield Unit-based threshold, and subsequently computing the summation of the calcium areas in each slice. However, when the carotid volume has intermittently higher concentration of contrast agent, a dependable approach is adapted to correct the calcium region using the neighboring slices, thereby estimating the correct volume. Furthermore, mitigation is provided following the regulatory constraints by changing the system to semi-automated criteria as a fall back solution. We evaluate the automated and semi-automated techniques using completely manual calcium volumes computed based on the manual tracings by the neuroradiologist.

RESULTS: A total of 64 patients with calcified plaque in the internal carotid artery were analyzed. Using the above algorithm, our automated and semi-automated system yields correlation coefficients (CC) of 0.89 and 0.96 against first manual readings and 0.90 and 0.96 against second manual readings, respectively. Using the t-test, there was no significant difference between the automated and semi-automated methods against manual. The intra-observer reliability was excellent with CC 0.98.

METHODS: The Malay version was translated by two independent translators who were well versed in both languages. We carried out a cross-sectional study collecting data between June 2017 and March 2018 in the pre-operative Eye Clinic of Hospital Melaka with 224 respondents (mean age 66.8 years) and another 204 respondents (mean age 64.3 years) participating in the English version and Malay version of the Questionnaire respectively. Methods used to validate the standard questionnaire included the use of construct validity via factor analysis and the deployment of reliability test through assessment of internal consistency via Cronbach's alpha.

RESULTS: We observed both English and Bahasa Malaysia versions to have high reliability with Cronbach's alpha values of 0.90 and above in factors on difficulty with activities and responses to vision problems. Exploratory factor analysis performed revealed that the three-factor model fits the data well for the English version of the questionnaire - difficulty with activities (23.81 % of variance), responses to vision problem (22.22 % of variance) and general health and vision (14.68 % of variance). The Bahasa Malaysia version of the questionnaire produced three factors with two of the factors resembling the factors from the original version of the questionnaire - difficulty with activities (24.3 % of variance) and responses to vision problem (23.7 % of variance). Item response theory analysis revealed that these factors for both English and Bahasa Malaysia versions comprised of adequately fitted items.