NSERC grants at Laurentian University Subventions du CRSNG `a l ...

104Robert LeclairA systematic approach for determining whether a low-anglex-ray scatter detection system could improve the detection ofbreast cancersA grant of $23,500 per year.Une subvention de 23 500 $ par année.Discovery Grant – Subvention à la découverteIn conventional mammography, breast structuresare more easily distinguished if their properties toattenuate x rays are significantly different. The absorptionof radiation is largely governed by the atomiccomposition and density of tissue. The tasksof detecting small cancers within a fibrous breastare difficult because the properties to absorb x rays for these tissue typesare similar. These particular imaging tasks are challenges even for the newerstate-of-the-art digital mammography systems. Though the propertiesof carcinoma and fibrous tissue to absorb x rays are similar, there is reasonto believe that the x-ray diffraction (i.e. low-angle x-ray scatter) signals ofthese tissue types could offer a new source of contrast that could improve thediagnosis of breast cancer. The x-ray diffraction signals are characteristic ofthe molecular structures of the tissue.The first objective of the project consists of measuring the low-angle x-ray scatter signatures of human breast tissues. I have established links withMedical Personnel from the Hôpital Régional de Sudbury Regional Hospital(HRSRH), the Sudbury Regional Breast Health Program, and from the SudburyRegional Pathology Associates. Our research program has been ethicallyapproved by the Research Ethics Board at Laurentian University and by theResearch Ethics Committee at the HRSRH. We have so far recruited 50 specimens.They are stored in our lab in liquid nitrogen. With an equipmentgrant from NSERC, we have built a custom made energy dispersive x-raydiffractometer. Briefly, it consists of a Faxitron X-Ray Model 43855C x-raycabinet system configured to house an ionization chamber, a system of collimators,a tissue sample holder, a cadmium zinc telluride detector (CZTD,3×3×2 mm 3 ), and several positioning devices. Although our CZTD has the