The purpose of this study was to evaluate the bone mineral density (BMD) of 50 patients aged 9-28 years, with thalassemia major and to assess the alterations of bone density in a 4-year follow-up study. They were measured with a DPX densitometer at the lumbar spine and femur area and divided into three groups: preadolescents, adolescents, and adults. All patients received calcium and vitamin D supplements, and 8 of the 50 received hormone replacement therapy (HRT). All patients had a significantly lower BMD compared with healthy subjects. Mean values of lumbar BMD of the three groups were 1.3, 2, and 3 standard deviations (SDs) lower than those of healthy subjects of the same age. All adolescent patients with normal gonadal function and those who received HRT showed an increase in BMD during the period of the study. Adult patients also showed an increase in bone density as long as the treatment lasted. However, adolescent and adult patients who had hypogonadotropic hypogonadism but could not get therapy showed a decrease in bone density. BMD of patients with thalassemia major shows a good index of bone status which should be evaluated, especially for the determination and follow-up of therapy.
Patients who undergo interventional radiological examinations and the medical doctors who perform them receive a noticeable radiation dose. Twenty-six angiographies and six angioplasties were included in the present study. They were classified as examinations of lower limbs, abdominal aorta and aortic arch/carotid artery. Thermoluminescent dosemeters (TLDs) were placed underneath and over the lead apron of the doctors at all of the 32 examinations as well as next to the eyes and over the thyroid of 22 patients. Dose area product (DAP) values, time duration and other parameters were registered. Patients' effective dose (ED) and doses to the various organs were calculated with the aid of ODS-60 software. The EDs were normalised to DAP measured in each procedure. Based on TLD measurements, the Niklason method was applied for the calculation of doctors' ED. The calculated ED by ODS-60 were in the range of 0.00-1.46, 2.63-49.32 and 0.07-45.12 mSv for the three groups, respectively, while E/DAP indices were 0.023, 0.310 and 0.105 mSv Gy(-1) cm(-2). Very good correlation was found between TLD measurements of the eye and the thyroid of the patients and the relative values calculated by ODS-60. The ED for the radiologists ranged from 0.4 to 47.0 μSv for all the procedures. Taking into consideration the annual number of examinations performed in the department, the estimated dose to the radiologists' eyes is considerably high, so wearing leaded glasses is recommended for the optimisation of the procedure.
The aim of this study was to measure the absorbed dose to seven organs other than the breast in mammography in order to calculate their contribution to the effective dose. The absorbed dose to these organs was measured using a lucite upper body anthropomorphic phantom containing thermoluminescent dosimeters (TLD) at appropriate locations, exposed as in a mammographic examination. In addition, the dependence of the absorbed dose on kVp, mAs and breast thickness was examined. The absorbed dose due to scattered radiation was found to be negligible to all organs except to the sternum red bone marrow (SRBM) and the thyroid. The mean doses to the SRBM and the thyroid, for a set of four exposures, one craniocaudal and one 90 degrees mediolateral per breast, simulating a complete breast screening examination, varied between 0.40 and 1.27 and 0.05-0.17 microGy mAs(-1), respectively, depending on the breast thickness and the kVp selection. Effective dose from mammography was also calculated based on the absorbed dose to the breast, the SRBM and the thyroid and tissue-weighting factors. The effective dose was found to vary between 0.66 and 0.85 microSv mAs(-1) depending on the breast thickness and the kVp value selected. The radiation dose to the breast contributes over 98% to the effective dose.
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