Ultrasound in medicine & biology
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Ultrasound Med Biol · Apr 2007
Flow volume in the jugular vein and related hemodynamics in the branches of the jugular vein.
Venous reflux in the internal jugular vein branches (JB) was found frequently in patients of certain neurologic disorders. We hypothesized that the retrograde-flow in JB is associated with retrograde hypertension transmitted from the internal jugular vein (IJV), which presumably underlies those neurologic disorders. In this study, we used color-Doppler imaging to evaluate the dynamic venous flow patterns in the IJV and its branches in 50 normal individuals (21 men, 29 women; mean age: 40.9 +/- 14.9 y, range: 22 to 70 y). ⋯ During the Valsalva maneuver (VM), 38 JB (38%) had a retrograde-flow. Retrograde-flow in JB was significantly associated with IJV valve incompetence (OR = 7.6; 95% CI = 2.6 to 21.8; p = 0.0002) and greater IJV blood flow volume (blood flow volume >670 mL/min) (OR = 6.6; 95% CI = 1.8 to 24.5; p = 0.0052), both of which may reflect higher IJV pressure transmission during VM. The sonographic findings can be used in the future studies of diseases that are suspected to be related with retrograde cerebral venous hypertension due to an elevated IJV venous pressure.
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Ultrasound Med Biol · Mar 2007
Comparative StudyDiagnosis of gallbladder diseases by contrast-enhanced phase-inversion harmonic ultrasonography.
We evaluated the usefulness of contrast-enhanced ultrasonography(US) for detecting and differentiating gallbladder lesions. Contrast-enhanced coded phase-inversion harmonic US was performed on 90 patients with gallbladder abnormalities. After administering Levovist, we observed the gallbladders in real time. ⋯ While the majority of carcinomas (86%) were type 1 or 2, three benign lesions also showed these patterns. Thus, the vascular pattern may simply reflect the size of the lesion and therefore its usefulness in diagnosing gallbladder lesions may be limited. Nevertheless, contrast-enhanced US is clearly superior to the other techniques in discriminating biliary sludge from other lesions.
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Ultrasound Med Biol · Mar 2007
Identification of cardiovascular dilution systems by contrast ultrasound.
Indicator dilution techniques permit accurate measurements of important cardiovascular parameters, such as pulmonary blood volume (PBV) and ejection fraction (EF). However, their use is limited by the need for central catheterization. Contrast ultrasonography allows overcoming this problem. ⋯ No subsequent model interpolation is needed. Volume measurements show accurate in-vitro results and clinical feasibility, while 50 EF measurements in patients show a 0.88 correlation coefficient with echocardiographic biplane estimates. In conclusion, adding a priori knowledge to the system identification algorithm leads to increased accuracy and robustness of the method for PBV and EF measurements.
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Ultrasound Med Biol · Mar 2007
Case ReportsColor Doppler US pulmonary artery vessel signal: a sign for predicting the benign lesions.
The lung cancer blood supply originates from the bronchial artery. If vessel signals within pulmonary lesions can be confirmed to be those of the pulmonary artery, color Doppler ultrasound (US) should be able to predict and differentiate benign lesions from lung cancers. Two hundred sixty-four patients with abutting thoracic lesions (including 125 lung cancers and 139 benign lesions) underwent color Doppler US examinations. ⋯ Analyzing the pulsatile flow vessel signals, the color Doppler US pulmonary artery vessel signal was present in 74 (53%) benign lesions, but was found in only two (2%) lung cancers of a specific alveolar cell carcinoma with lobar consolidation. Using the pulmonary artery vessel signal, color Doppler US can be valuable in predicting and differentiating benign lesions from lung cancers (p < 0.0001, sensitivity = 0.53, specificity = 0.98 and positive likelihood ratio 26.5). In conclusion, color Doppler US pulmonary artery vessel signal sign is useful in predicting and differentiating benign lesions from lung cancers.
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Ultrasound Med Biol · Jan 2007
Image-guided acoustic hemostasis for hemorrhage in the posterior liver.
We investigated the use of ultrasound image-guided high intensity focused ultrasound (HIFU) to stop bleeding from injuries in the posterior liver. A HIFU transducer with focal length of 3.5 cm and frequency of 3.2 MHz was integrated with an intraoperative high-resolution ultrasound-imaging probe. Wedge tissue extractions, 30-mm long, 5-mm wide and 8-mm deep, were made in the posterior liver surface of five pigs to induce bleeding. ⋯ Hemostasis was achieved in 66 +/- 18 s (mean +/- standard deviation) for 17 HIFU treatments. During 7 min of sham HIFU treatment, none of the control incisions (n = 7) became hemostatic. Ultrasound image-guided HIFU offers a promising method for hemostasis in surgical settings in which the hemorrhage site is hidden and/or not accessible.