Iopromide injection

Tungsten (VI) chloride and 1-octadecanol were purchased from Macklin (Shanghai, China). Oleic acid and 1-octadecene were obtained from Sigma Aldrich. Titanium (IV) ethoxide was purchased from Alfa Aesar (UK). DSPE-PEG₅₀₀₀ was purchased from Shanghai Yudu Biotechnology (China). Acetone, hexane, and chloroform were purchased from Yonghua Chemical Technology (Jiangsu, China). Iopromide injection was purchased from Bayer Pharma AG (Germany). The 4T1 cells were provided by the Shanghai Center for Systems Biomedicine (Shanghai, China). A cell counting kit-8 (CCK-8) kit was obtained from BBI Solution (UK). Female BALB/c nude mice of 5~6 weeks old were obtained from Slac Laboratory Animal Center (Shanghai, China).

Patients underwent contrast-enhanced CT examinations using one of the following systems: Revolution CT (GE Healthcare) or SOMATOM definition (Siemens). The CT examination included three phases: precontrast, arterial, and portal vein phase. Arterial phase scanning started about 30–35 s after the beginning of injection, and portal phase was obtained after 2 min with the contrast injection. The following parameters were used: tube voltage, 120 kVp or 100 kVp; tube current, 200–450 mA; slice thickness, 1.25 mm; pitch, 0.992 : 1; rotation speed: 0.5 s/rot; ASIR-V: 20%. All patients received an intravenous, nonionic contrast medium (iodine concentration, 370 mg/mL; volume, 1.5–2.0 ml/kg of body weight; contrast type, Iopromide Injection, Bayer Pharma AG) at a rate of 2-3 ml/s, and after contrast agent injection, a 20 ml saline was injected for the flush.

The individuals under study underwent contrast-enhanced CT using one of the following systems: Sensation 64 CT (Siemens, Munich, Germany) or Sensation 16 CT (Siemens, Munich, Germany). Triple-phase CT examinations were conducted, including non-enhanced, arterial, and portal vein phases. The abdomen scouts were acquired from the dome of the diaphragm to the iliac crests. The arterial phase of the same region started at approximately 20–30 s after the administration of contrast agent, followed by the portal phase (30–40 s). Reconstructions were performed on a GE Advantage Windows 3D workstation (GE Healthcare, Waukesha, WI, USA) with the reconstitution thickness set at 1–2 mm. The detailed scanning parameters were listed as follows: tube voltage, 120 or 100 kVp; tube current, 150–600 mA; slice thickness, 1.25 mm; and pitch, 1.375. All patients received an intravenous, nonionic contrast agent (iodine concentration, 370 mg/mL; volume, 1.5–2.0 mL/kg of body weight; contrast type, iopromide injection (Bayer Pharma AG, Leverkusen, Germany)) at a rate of 3–5 mL/s. Then, 20-mL saline was injected after contrast injection.

All patients underwent a multi-slice CT scan with four phases including unenhanced, arterial, portal venous, and delayed contrast-enhanced phase, using the following systems [LightSpeed VCT (GE Healthcare, Chicago, IL, USA), Sensation 64 CT (Siemens, Erlangen, Germany), or Sensation 16 CT (Siemens)] in West China Hospital. The scanning parameters were as follows: 100 or 120 kVp; tube current, 150–600 mA; slice thickness, 5 mm. After plain scanning was completed, a non-ionic contrast medium (iodine concentration, 370 mg/ml; volume, 1.5–2.0 ml/kg of body weight; contrast type, Iopromide injection, Bayer Pharma AG, Berlin, Germany) was injected at 3–5 ml/s through the antecubital vein, and 20 ml saline was injected after the injection of the contrast. Arterial phase, portal venous phase, and delayed phase scanning started at 30, 60, and 180 s after the contrast medium was injected.