Sensation 64 scanner

The 10 primary sonographically guided PSTJ injections performed in the Procedural Skills Laboratory were completed using an iU22 ultrasound machine and a 17-5-MHz linear array transducer (Philips Healthcare, Bothell, WA). The sonographically guided PSTJ injection performed for CT validation was completed using a CX50 portable ultrasound machine and a 12-3-MHz linear array transducer (Philips Healthcare). The CT-guided PSTJ injection and the CT scans after both the sonographically guided and CT-guided injections were performed using a Sensation 64 scanner (GE Healthcare, Waukesha, WI) with the following parameters: collimation, 12 × 0.3 mm; pitch, 0.8; reconstruction slice and increment, 0.4 to 0.6 and 0.2 to 0.6 mm; tube voltage, 140 kV (peak); and tube current, 250 mA. All injections were performed using 25-gauge, 38-or 50-mm stainless steel needles.

The CT scans were obtained through the use of 2 dedicated mobile scanners (93%) or, beginning in 2012, at 2 imaging facilities in Las Vegas and Idaho Falls (7%).
From 2000 to 2006, a coach-mounted, single-slice General Electric HiSpeed DX/I (GE Medical Systems, Milwaukee, WI) was used to obtain full-chest, helical CT scans with a low-dose technique (120 kilovolt peak [kVp], 40-50 milliamps, pitch of 1.5, 7-millimeter collimation). From 2006 to 2013, we performed CT scanning with Siemens Emotion 16, 16-slice scanners (Siemens, Malvern, PA) at most program sites, supplemented by a Siemens Sensation 64 scanner in Las Vegas and a General Electric Lightspeed 16-slice scanner in Idaho Falls in 2012. We selected kilovolt peak, tube current, pitch, and other scanner parameters to produce a CT dose index for a standard-sized patient, which was within the guidelines for low-dose chest CT scan (1.5-2.3 mGy). The average estimated effective dose across all scanners was 1 millisieverts (range = 0.8-1.2 mSv).
Of 16 229 scans, 90% (14 674) were interpreted by a single senior academic thoracic radiologist (J. M.), and the remaining scans were read by experienced radiologists in DOE communities.