Isite

Chest CT was performed in the supine position during inspiratory breath-hold from the apex to the lung bases, on either a 64-slice CT scanner (Philips Brilliance, Philips Healthcare, The Netherlands) or on a 128-slice scanner (Toshiba Aquillion, Japan) with or without intravenous contrast media administration at the physician's discretion. Scanning parameters followed institutional protocols for each machine and patient body type and were collimated at 64×0.625 or 0.6 mm, 120 kVp, 667 max mA or 404 max mA, pitch 1.0 or 1.2, and matrix size 512×512. CT images were reconstructed in the transverse plane with 1.0-mm slice thickness and 1.0-mm increment. All images were stored and accessed through an integrated PACS (Picture Archiving and Communication System, PHILIPS iSite, version 4.1.110.0, USA).

Imaging was performed on 1.5-T and 3.0-T scanners (Siemens, Erlangen, Germany). Liver MRI protocol included axial T1-weighted dual echo in-phase and out-of-phase imaging and axial T2 balanced gradient echo (TrueFISP). Dynamic contrast-enhanced gradient-echo T1-weighted images with fat suppression were obtained at 4 timepoints: pre-contrast, arterial phase (8 s after contrast administration), venous phase (70 s after contrast administration), and delayed phase (180 s contrast administration). The intravenous contrast agents used during the study period were Gadavist (Bayer, Berlin, Germany) and Eovist (Bayer). The contrast injection was performed with 10 cc of the contrast agent injected at a rate of 2 cc/sec, followed by a 10 cc saline flush.
DW imaging consisted of fat-suppressed single-shot echo planar sequences obtained during breath holds and performed at b-values of 50, 400, and 800 s/mm². ADC maps were automatically calculated and displayed on a standard picture archiving and communication system (iSite, Philips, Amsterdam, The Netherlands).

This study was approved by the university institutional review board and, given its
retrospective nature, the requirement for informed consent was waived.
Seven cases of gastric lipoma diagnosed incidentally on CT from 2003 to 2017 were reviewed
by a body trained radiologist on a picture archiving and communication system (PACS; iSite,
Phillips). Recorded variables on CT imaging included mean diameter (average of the
anteroposterior, transverse, and craniocaudal dimension), location within the stomach
(cardia, fundus, body, antrum, pylorus), and mean attenuation in Hounsfield units (HU).
Volume was estimated using the standard ellipsoid formula, V = (π/6)(length ×
width × height). The mean attenuation of lesions was measured by placing the largest
possible round region of interest while attempting to avoid the wall. One patient underwent
MRI, for which T₂ and opposed phase gradient echo imaging characteristics of the lesion were
recorded. One patient underwent fludeoxyglucose- positron emission tomography/CT (PET/CT)
imaging. These images were fused and viewed with Aquarius iNtuition (Terarecon Inc.), and a
mean standardized uptake value (SUV) was obtained. Endoscopic images for this case were also
reviewed with a board certified gastroenterologist. Pathology for this case was reviewed
with a board certified pathologist.