ABSTRACT
Purpose: To compare the image quality of the low-dose to the standard-dose protocol of MDCT scanning of the paranasal sinuses, based on subjective assessment and determine the radiation doses to the eyes and thyroid gland and dose reduction between these two protocols. Materials and Methods: 31 adult patients were scanned. Prior to scanning, thermoluminescent dosimeters (TLDs) were placed at 4 sites: outer canthus of right eye, outer canthus of left eye, inner canthus and anterior neck (thyroid gland). Every patient was scanned twice using the standard-dose protocol (100mAs) followed by the low-dose protocol (40mAs). The images were reviewed by 3 radiologists. Wilcoxon test was used as the test of significance for the image quality assessments. The paired sample t-test was used as the test of significance for the analysis of the radiation doses measured by the TLDs. Results: Of the 30 patients selected for analysis, this study showed no significant difference in the scores for the diagnostic image quality and the anatomical structures assessments between the two protocols. The average calculated mean entrance surface doses and standard deviation for the standard-dose and low-dose protocols were 12.40±1.39 mGy and 5.53±0.82 mGy respectively to the lens and 1.03±0.55 mGy and 0.63±0.53 mGy respectively to the thyroid gland. Conclusion: The reduction of mAs from 100 to 40 resulted in a significant reduction of the radiation doses to the lens and thyroid gland by 55.4% and 38.8% respectively without causing any significant effect to the diagnostic image quality and assessment of the anatomical structures.
ABSTRACT
To date, the College of Radiology (CoR) does not see any clear benefit in performing whole body screening computed tomography (CT) examinations in healthy asymptomatic individuals. There are radiation risk issues in CT and principles of screening should be adhered to. There may be a role for targeted cardiac screening CT that derives calcium score, especially for asymptomatic medium-risk individuals and CT colonography when used as part of a strategic programme for colorectal cancer screening in those 50 years and older. However, population based screening CT examinations may become appropriate when evidence emerges regarding a clear benefit for the patient outweighing the associated radiation risks.
ABSTRACT
Informal discussion started in 1996 and the South East Asian Federation of Organizations for Medical Physics (SEAFOMP) was officially accepted as a regional chapter of the IOMP at the Chicago World Congress in 2000 with five member countries, namely Indonesia, Malaysia, Philippines, Singapore and Thailand. Professor Kwan-Hoong Ng served as the founding president until 2006. Brunei (2002) and Vietnam (2005) joined subsequently. We are very grateful to the founding members of SEAFOMP: Anchali Krisanachinda, Kwan-Hoong Ng, Agnette Peralta, Ratana Pirabul, Djarwani S Soejoko and Toh-Jui Wong. The objectives of SEAFOMP are to promote (i) co-operation and communication between medical physics organizations in the region; (ii) medical physics and related activities in the region; (iii) the advancement in status and standard of practice of the medical physics profession; (iv) to organize and/or sponsor international and regional conferences, meetings or courses; (v) to collaborate or affiliate with other scientific organizations. SEAFOMP has been organizing a series of congresses to promote scientific exchange and mutual support. The South East Asian Congress of Medical Physics (SEACOMP) series was held respectively in Kuala Lumpur (2001), Bangkok (2003), Kuala Lumpur (2004) and Jakarta (2006). The respective congress themes indicated the emphasis and status of development. The number of participants (countries in parentheses) was encouraging: 110 (17), 150 (16), 220 (23) and 126 (7). In honour of the late Professor John Cameron, an eponymous lecture was established. The inaugural John Cameron Lecture was delivered by Professor Willi Kalender in 2004. His lecture was titled “Recent Developments in Volume CT Scanning”.