Osirix md

Paraspinal CT measurements for each older adult undergoing treatment were obtained from their medical records from routine non-contrast CT of the chest. We used axial images localized to the twelfth thoracic vertebrae (T12) in CT image analyses in Osirix MD (Pixmeo, Bernex, Switzerland). We placed 2 cm² ovoid ROIs in the erector spinae muscles bilaterally and the Hounsfield units (HU) were averaged to obtain erector spinae HU (see Figure 1). If the available erector spinae areas were <2 cm², the largest available region of interest was used. Eight CT scans were non-contrast, and two had early arterial phase contrast. CT scanners used were GE Revolution HD (n = 4), GE Revolution EVO (n = 3), and GE Optima (n = 3) (GE Healthcare, Madison, WI) and all but 1 scan was conducted at the University of Wisconsin Health Hospital in Madison, WI.

We aligned the patient DICOM dataset and the 3D model DICOM dataset in Osirix MD (Pixmeo, Geneva, Switzerland) by creating a fusion image of the two DICOM files. Detailed instructions for making fusion images are available online (https://en.wikibooks.org/wiki/Online_OsiriX_Documentation/Making_fusion_images).
The heart holder positioned the model in the same spatial coordinates and alignment as the patient’s heart on the initial scan, and thus there was no requirement for non-rigid deformation. Minimal differences in X, Y and Z coordinates between the two DICOM datasets were corrected using the pan and rotate tools in Osirix.

Five-to-seven years post-implantation, the same sheep cohort underwent fluid overload stress testing. Two sheaths were inserted into the right internal jugular vein to guide the placement of two catheters: one into the abdominal IVC for contrast injection and one into the midgraft region for pressure measurement. 3D angiography and intra-graft pressure measurements were obtained concurrently before and after the administration of a saline bolus (20 ml/kg). All images were analyzed using Osirix MD® (Pixmeo SARL, Geneva, Switzerland) to determine cross-sectional area and circumference at five locations: low intrathoracic IVC (5 mm below the proximal anastomosis), proximal anastomosis, midgraft, distal anastomosis, and high intrathoracic IVC (5 mm above the distal anastomosis). The proximal and distal anastomoses were identified through surgically placed radiopaque markers. Compliance (2) and distensibility (3) were calculated using the following equations: $Compliance=\frac{A_{post}-A_{pre}}{P_{post}-P_{pre}}\left[{\mathrm{cm}}^2/\mathrm{mmHg}\right]$ $Distensibility=\frac{\frac{C_{post}-C_{pre}}{C_{pre}}}{P_{post}-P_{pre}}\times {10}^4\left[\%/100\mathrm{mmHg}\right]$ where A is cross-sectional area (cm²), C is circumference (cm), and $P$ is pressure (mmHg). Note that the pressure difference due to a bolus injection was 11.4 ± 3.15 mmHg for both classes of grafts, thus facilitating comparisons between TEVG and PTFE.

The 3D shape of the eyeball was measured as an area of high signal index on T2-weighted 3D-MRI images^{13 (link)}. The MRI examinations were performed at 3.0 T using a Philips Achieva (Philips Healthcare, Best, The Netherlands). The participants were instructed to keep both eyes closed with minimal movement during the scanning. Scanning sequences (repetition time = 2500 ms; echo time = 248 ms; flip angle = 90°; field of view = 256 $\times$ 256 $\times$ 188 mm) were performed with maximum water-fat shift^{15 (link)}. The image resolution was 1 $\times$ 1 $\times$ 1 mm. Volume rendering of the images was performed using commercially available software (OsiriX MD; FDA cleared, Pixmeo, Bernex, Switzerland).