Biomedical subjects

N Ban

Publications and source records attributed to N Ban.

At least 91 records · Page 5Linked to original sources

PubMed1987

Central signals of gallstones in magnetic resonance imaging.

The magnetic resonance imaging of gallstones was studied in 34 patients. Diagnosis of the gallstones using magnetic resonance imaging was possible in 29 patients (85%). The gallstones showed as no-signal areas in all cases, with relatively strong signals being detected from the center of the stones in six cases. Postoperative studies showed the stones with the central signals to be of the so-called mixed stone type, in which the central area consists of cholesterol with a radiating structure. The central signal was thought to originate in water that accumulates in the central cavity of the stone, the cavity not being isolated from the exterior of the stone and there being a passage of fluids. The central signal is a characteristic indication of the stone's structure.

Cholelithiasis↗

PubMed1986

Clinical application of an ultrasonic duplex system in the quantitative measurement of portal blood flow.

The ultrasonic duplex system, which is composed of a pulsed Doppler flowmeter and a linear array B-mode scanner, was developed for the purpose of quantitative transcutaneous measurement of blood flow. It was applied here to the study of portal blood flow in a normal series with healthy volunteers as subjects. A preliminary experiment, prepared by setting up a simulation model for blood circulation, demonstrated an excellent correlation between values obtained with the electromagnetic flowmeter (EMF) and the combined ultrasonic B-mode and Doppler system (duplex system). This was confirmed in vivo in a study of blood flow in the canine vena cava. The portal blood flow in 88 healthy adult volunteers ranging in age from 18 to 55 years (average 34.3) was studied using this equipment. Blood flow in fasting subjects who were resting was 889 +/- 284 ml/min (mean +/- SD) or 16.3 +/- 5.0 ml/min/kg body weight (mean +/- SD).

Adolescent↗

PubMed1986

Hemodynamics of splenic artery aneurysm.

Blood flow volume of the portal venous system of 3 patients with splenic artery aneurysm, an uncommon disease, was measured using an ultrasonic duplex system. A huge increase in splenic blood flow volume was found in each case. A large portasystemic shunt through which the portal blood flowed hepatofugally was present in 2 cases. We suspect the shunt is partially responsible for an increase in splenic blood flow volume, which would lead to the formation of splenic artery aneurysm together with portal hypertension.

Adult↗

PubMed1986

Measurement of portal vascular resistance in patients with portal hypertension.

Portal vascular resistance was measured percutaneously in 60 patients with chronic liver disease and in 5 control subjects. The portal vascular resistance (PVR) was calculated, using the following equation, from the portal blood flow (QPV), portal venous pressure (PPV), and hepatic venous pressure (PHV): PVR = (PPV - PHV)/QPV. The portal blood flow was measured using an ultrasonic Doppler duplex system, and the portal venous and hepatic venous pressures were measured using percutaneous transhepatic catheterization and venous catheterization, respectively. The wedged hepatic venous pressure was measured by occluding the hepatic venous branch using a balloon catheter. The portal vascular resistance was 0.25 +/- 0.13 mmHg X ml-1 X min X kg body weight (mean +/- SD, n = 5) in the control group, 0.64 +/- 0.29 mmHg X ml-1 X min X kg body wt (n = 13) in the chronic active hepatitis group, 1.34 +/- 0.79 mmHg X ml-1 X min X kg body wt (n = 30) in the cirrhosis group, and 0.85 +/- 0.69 mmHg X ml-1 X min X kg body wt (n = 13) in the idiopathic portal hypertension group.

Blood Flow Velocity↗

PubMed1986

Portal hemodynamics in patients with hepatocellular carcinoma.

The protal blood flow was assessed in 46 patients with hepatocellular carcinoma, 81 with cirrhosis, and 110 control subjects using an ultrasonic B-mode pulsed Doppler duplex system. The cross-sectional area of the portal vein was increased, and the velocity of portal blood flow was decreased in hepatocellular carcinoma and cirrhosis, whereas the blood flow volume was not significantly different. A significant decrease in portal blood flow was found in hepatocellular carcinoma only when at least three of the four major branches of the portal vein were occluded. The change in portal hemodynamics before and after transcatheter arterial embolization (TAE) was investigated. Immediately after TAE, neither portal venous pressure nor portal blood flow showed any constant trend. The portal blood flow reached a peak 1 week after TAE and then returned to its former value after 3-4 weeks, while all cases with poor prognoses showed a drop in portal blood flow after TAE.

Aged↗

PubMed1986

"Congestion index" of the portal vein.

The "congestion index" is used to mean the ratio between the cross-sectional area (cm2) and the blood flow velocity (cm/sec) of the portal vein, as determined by a duplex Doppler system. The indices as determined in normal subjects and patients with liver disease were as follows: normal subjects (n = 85), 0.070 +/- 0.029 cm X sec; acute hepatitis (n = 11), 0.071 +/- 0.014 cm X sec; chronic active hepatitis (n = 42) 0.119 +/- 0.084 cm X sec; cirrhosis (n = 72), 0.171 +/- 0.075 cm X sec; and idiopathic portal hypertension (n = 11), 0.180 +/- 0.107 cm X sec. There was a statistically significant difference between the congestion indices from the normal subject group and indices obtained from patients with chronic hepatitis, cirrhosis, and idiopathic portal hypertension. A weak positive correlation was obtained between the congestion index and the portal venous pressure, measured simultaneously through a percutaneously placed catheter (n = 64, r = 0.45, p less than 0.01). It is suggested that the congestion index reflects the pathophysiological hemodynamics of the portal venous system in portal hypertension.

Blood Flow Velocity↗

PubMed1986