shu-508 and Gastrointestinal-Hemorrhage

Topics: Colonic Neoplasms; Contrast Media; Digestive System; Gastrointestinal Hemorrhage; Humans; Ileal Neoplasms; Image Enhancement; Polysaccharides; Ultrasonography

The induction by ultrasound (US) of petechiae and hemorrhages in mouse intestine was examined with injection of gas body-based contrast agents. Production of petechiae in the intestinal wall was enhanced by contrast agents for both continuous and pulsed (10 micros pulses repeated at 1 kHz) exposure relative to a gas body-free blank. For pulsed exposure with 10 mL/kg of Albunex, apparent thresholds for peak negative pressure amplitude were 0.42 MPa at 0.4 MHz, 0.85 MPa at 1.09 MHz and 2.3 MPa at 2.4 MHz. Results at these frequencies were the same for 10-11 cycle pulses with fixed duty cycle (0.01). Thresholds for hemorrhage into the intestinal lumen were not appreciably enhanced by added Albunex, and appear to be compatible with previously reported lithotripsy data when duty factor differences are considered. The agents PESDA, Optison and Levovist had lower thresholds (for example, 1.8 MPa for Levovist) than Albunex at 2.3 MHz, and yielded more petechiae. The thresholds for petechiae induction by US with contrast agents encroach upon the exposure range relevant to diagnostic US practice.

Topics: Albumins; Animals; Contrast Media; Disease Models, Animal; Fluorocarbons; Gastrointestinal Hemorrhage; Intestinal Diseases; Intestines; Male; Mice; Mice, Hairless; Microspheres; Polysaccharides; Purpura; Ultrasonography

The aim of this study was to illustrate the versatility of an i.v. administered echo enhancer for Doppler US assessment of TIPS patency and function.. A total of 22 Doppler US evaluations of TIPS patency and function were performed in 5 patients with alcoholic cirrhosis and recurrent oesophageal bleeding who had been treated with TIPS. TIPS patency was evaluated by means of colour or power Doppler US. The volume flow (VF) was assessed in the TIPS and in the portal vein by spectral Doppler. The ratio of the VF in the TIPS to the VF in the portal vein (T/P ratio) was used to express the functional status of the TIPS. If Doppler signals were inconclusive or absent, echo-enhanced US was performed.. In 22 follow-up Doppler US examinations, echo-enhanced Doppler US was required in 7 cases (29%). The Doppler enhancement persisted in the range of 3-5 min. No adverse effects were observed. An apparently normal TIPS function reflected a T/P ratio in the range of 0.44-1.10, median 0.78 +/- 0.20 (2SD).. The i.v. administration of echo enhancers would seem to be indicated in the assessment of the TIPS function if conventional Doppler US fails to prove normal TIPS patency and function. The T/P ratio may be a convenient monitoring parameter for reflecting the TIPS function.

Topics: Adult; Aged; Blood Flow Velocity; Contrast Media; Esophageal and Gastric Varices; Female; Follow-Up Studies; Gastrointestinal Hemorrhage; Humans; Image Enhancement; Liver Cirrhosis, Alcoholic; Male; Middle Aged; Polysaccharides; Portal Vein; Portasystemic Shunt, Transjugular Intrahepatic; Portography; Recurrence; Treatment Outcome; Ultrasonography, Doppler