This work provides the results of a collaboration between the Human Monitoring Laboratory (HML) and the Centre Hospitalier de l'Université de Montréal (CHUM) in which CHUM provided CT lung image sets from 166 patients for the analysis of linear dimensions and lung volume. This work has shown that a large amount of data exists in the medical community that can be of value to the health physics community. The intent of this study was to determine the range of linear dimensional parameters that could be used for torso phantom development for males and females; understand and characterize the variability of linear lung dimensions for males and females; replace the brief table in ICRP 23 with more modern data for males and females; identify an empirical formula that would predict linear dimensions of human lungs from age, height and/or weight for males and females; characterize the left, right, and total lung volumes of males and females in this data set; and compare the lung volumes of males and females to published equations for determining lung volumes. It was found that linear dimensions of lungs are essentially independent of age, height, and weight, so predictive equations cannot be formulated; however, the ranges of those parameters have now been established for the population studied herein. The data presented here are more modern than the brief table that appeared in ICRP 23, and the average values could be used as future guidelines. Whole lung volumes have been determined from the voxel lung phantoms, and empirical formulae have been developed for males and females in this data set; these compare favorably with the published values in ICRP 66.

Dose indicators such as the computed tomography dose index (CTDI) and dose-length product (DLP) were gathered for all routine abdomen-pelvis, chest and head examinations performed on all computed tomography (CT) scanners at a University Health Center (UHC) in Canada. These indicators were analysed and compared with the range of diagnostic reference levels (DRLs) suggested by Health Canada and with DRLs in other countries. Mean DLP values varied from one scanner to another, but mean values at the UHC (750 mGy cm(-1) for abdomen-pelvis CT, 349 mGy cm(-1) for chest CT and 1181 mGy cm(-1) for head CT) were all below the upper limit of the range of DRLs suggested by Health Canada. Local DRLs at the UHC were set to 810 mGy cm(-1) for abdomen-pelvis CT, 345 mGy cm(-1) for chest CT and 1205 mGy cm(-1) for head CT. Results, however, show the need for protocols revisions, since some scanners exhibit mean DLP values slightly below or above the upper limit of the range of DRLs suggested by Health Canada.

Background and Purpose-Endovascular treatment of intracranial aneurysms is safe and effective but is associated with angiographic recurrences. Beta radiation prevents recanalization after coil embolization in experimental models. We wanted to assess the feasibility of using radioactive coil embolization to improve long-term results of endovascular treatment. Methods-Platinum coils were ion-implanted with 0.13 to 0.26 Ci/cm of 32 P. Forty-one patients aged 34 to 84 years with 44 aneurysms with a high propensity for recurrences were included. Radioactive coils were introduced into aneurysms to reach a target volumetric activity of 0.018 Ci/mm 3 . Nonradioactive coils were also used to ensure the same safety and the same angiographic results as the standard procedure. Angiographic results, procedure-related complications, and neurological events during follow-up were recorded. Angiographic follow-up data are available in 36 lesions 6 months after treatment. Results-Forty of 44 aneurysms (91%) could be treated with radioactive coils. Target activities could be reached in 88% of lesions that could actually be coiled (35/40). Total activities ranged from 1.72 to 80.9 Ci, for a mean of 20.13Ϯ20.80 Ci. Procedure-related complications occurred in 7% of patients. Initial angiographic results were satisfactory (complete occlusions or residual necks) in 75% of lesions. Angiographic recurrences occurred in 11 (31%) of patients followed, within the expected range for standard coils. There was no complication from beta radiation during a mean follow-up period of 10 months. Conclusions-Radioactive