Radiological site characterizations: gamma surveys, gamma/226Ra correlations, and related spatial analysis techniques.

Radiological surveys of a uranium mill site in Colorado and several proposed uranium recovery sites in Wyoming were conducted in 2006 and 2007. Advancements in Global Positioning System (GPS)-based gamma scanning systems combined with gamma/Ra correlations and Geographic Information Systems (GIS)-based spatial analysis techniques produced comprehensive and detailed characterizations of the spatial distributions of gamma exposure rates and Ra concentrations in surface soils across extensive study areas. Aside from limitations on gamma-based estimates of soil Ra related to soil heterogeneity or gamma shine effects, soil sampling results to date show good general agreement between estimated and measured values.

The Quebec Heart Institute: 50 years of excellence in cardiology.

The Quebec Heart Institute was established in 1957 at the Laval Hospital in Sainte-Foy, Quebec. Since then, clinical and research activities have made this Institute one of the largest tertiary care cardiology centres in Canada. With its vast catchment area of more than 3,000,000 people, the Institute has developed a strong collaboration with referral physicians centred on clinical, teaching and research interests.

Impact of implant technique following freestyle stentless aortic valve replacement.

Background: Stentless aortic bioprostheses have excellent hemodynamics and clinical outcomes. The purpose of the present study was to determine whether implant technique of the Freestyle aortic root bioprosthesis impacts clinical outcomes or hemodynamic performance.

Methods: The long-term multicenter study of the Freestyle stentless aortic bioprosthesis includes 500 consecutive patients implanted using the subcoronary and 162 using the full root technique.

Hemodynamic performance at rest and during exercise after aortic valve replacement: comparison of pulmonary autografts versus aortic homografts.

Background: The Ross procedure and aortic homografts have both been shown to have superior hemodynamic performance after valve replacement, but there have been few comparisons.

Methods: Sequential Doppler echocardiograms were performed up to 5 years after aortic valve replacement in 132 patients with the Ross procedure and 111 patients with an aortic homograft (AH). Measurements included assessment of valvular regurgitation and calculations of valve effective orifice area (EOA) and mean transvalvular gradients; the same measurements were also performed at the level of the pulmonary homograft in the Ross patients as well as during maximum exercise in 20 Ross patients and 14 AH patients.

Pacemaker contact sensitivity: case report and review of the literature.

Pacemaker contact sensitivity is a rare condition. Less than 25 reports of pacemaker skin reaction have been described over the past 30 years. This report describes one patient who developed contact dermatitis after implantation of two subsequent pacemakers.