Ge hd750

Subjects were positioned supine within a multidector-row CT scanner (GE HD750: GE Healthcare). Full lung scans were acquired during breath holds at coached TLC (inspiratory scan) and coached RV (expiratory scan) on visit 1 and visit 2. The scanning protocol was based on the SPIROMICS study protocol (67 (link)–70 (link)). The scan parameters for the GE HD750 were as follows: 120 kV and current of 180 mA for inspiratory scans and 100 mA for expiratory scans. The slice thickness was 0.625 mm with an interval of 0.5 mm and a pitch of 0.984:1. Spatial resolution was matched at baseline and follow-up using a similar diameter field of view for both scanning sessions. Scans were reconstructed with filtered back projection and standard kernel, and they were deidentified prior to transfer to the University of Iowa for analysis. Three deep breaths to standardize lung volume history preceded scans. Subjects were coached to reach TLC and RV, and the maneuvers were rehearsed prior to scanning.

CT examinations were performed on a variety of 16- and 64- slice multi-detector CT scanners (Siemens Somatom, GE lightspeed, GE HD750). MRI examinations were performed on 1.5 T scanner (Phillips). Most (64% [14/22]) examinations were performed at an outside institution and transferred to University of Michigan for re-interpretation and further management. The CT examinations at our institution were performed following intravenous administration of 100–125 mL of iodinated contrast material (300 mg/mL) acquired in either a single portal venous phase (60 s delay) or acquired in both arterial (30 s delay) and portal venous phases. All CT examinations were reconstructed with a slice thickness of 2.5–5 mm and were acquired with the following settings: 100–120 kVp, variable mA. MRI examinations were acquired utilizing routine liver or cholangiocarcinoma protocol (coronal and axial T2 weighted imaging), dual-echo in and opposed phase, coronal and axial 3D MRCP with 3-D reformats, axial fat saturated T1Weighted gradient echo pre and dynamic post contrast imaging (0.1 mmol/kg of Gadolinium based contrast agent), delayed (15 min) fat-saturation post contrast T1WI.