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Biomedical subjects

R Omoto

Publications and source records attributed to R Omoto.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Assessment of the effect of respiration on the esophageal variceal blood flow using transesophageal real-time two-dimensional Doppler echography.

The effect of spontaneous respiration on esophageal variceal flow was evaluated using 5 MHz color flow Doppler echography. Twenty-one patients with esophageal varices, of whom 19 had liver cirrhosis (95%), were examined with a convex array transesophageal transducer. The direction and velocity of the variceal flow during inhalation and exhalation could be inferred from the color, its brightness or the Doppler time-velocity spectrum. The mean intravariceal flow velocity was significantly higher during inhalation (20.6 cm per sec) than in exhalation (11.5 cm per sec; p less than 0.01). The direction of intravariceal flow at any given point did not change throughout the respiratory cycle. However, a combination of real-time color flow imaging and the doppler time-velocity spectrum revealed that, when the sampling point was near the peak of the curve of the varix, the spectrum falsely indicated reversal of direction between inhalation and exhalation. This semiinvasive method, which yields anatomical and physiological information simultaneously, appears to be very useful for the study of variceal flow.

Adult↗
PubMedDate not supplied

Percutaneous transhepatic biliary drainage guided by color Doppler echography.

Percutaneous transhepatic biliary drainage (PTBD) guided by color Doppler echography was performed on nine patients. By color Doppler echography, the segmental and subsegmental branches of both the portal vein and the hepatic artery could be identified and discriminated from the bile ducts because of their color flow mapping. We could select the safe pathway of needle advance, which did not injure the vessels. Thus, complication of bleeding did not occur in any of the patients. Color Doppler echography seems a very useful and safe method for the guidance of PTBD.

Adult↗