Learn More
The authors recorded the sound signals during suckle feeding of six normal infants within the first two postnatal days. The sounds were recorded onto a cassette tape-recorder from a small microphone attached to the infant's neck, then displayed on an oscilloscope and analysed by digital signal processing techniques. These displays demonstrated acoustic(More)
STUDY OBJECTIVE To determine the efficacy of continuous intravenous infusion of prostacyclin (epoprostenol) in primary pulmonary hypertension. DESIGN Randomized trial with 8-week treatment periods and nonrandomized treatment for up to 18 months. SETTING Four referral centers. PATIENTS Sequential sample of 24 patients with primary pulmonary(More)
PURPOSE To establish a quantitative magnetic resonance (MR) imaging contrast enhancement criterion for distinguishing cysts from solid renal lesions. MATERIALS AND METHODS Regions of interest were measured in 74 patients with renal lesions evaluated by means of dynamic contrast material-enhanced MR imaging with serial breath-hold spoiled gradient-echo(More)
Contrast-enhanced MR angiography (CE-MRA) using steady-state free precession (SSFP) pulse sequences is described. Using SSFP, vascular structures can be visualized with high signal-to-noise ratio (SNR) at a substantial (delay) time after the initial arterial pass of contrast media. The peak blood SSFP signal was diminished by <20% 30 min after the initial(More)
Bolus chase 3-dimensional MR angiography (3D MRA) is a recent development that extends the effective field of view for arterial imaging from the typical single 40-50 cm to over 100 cm. This technique is well suited for imaging long vascular territories such as the lower extremity. Bolus chase peripheral 3D MRA is achieved with overlapping 3D gradient-echo(More)
BACKGROUND Turner syndrome (TS) is associated with aortic coarctation and dissection; hence, echocardiographic evaluation of all patients is currently recommended. X-ray angiography in clinically symptomatic patients has suggested a range of other vascular anomalies, but the true prevalence of such lesions in TS is unknown. To better understand the(More)
To follow the motion of the coronary artery in magnetic resonance angiography, the authors evaluated vessel tracking, a method for prospective adjustment of the section location as a function of the delay from the cardiac trigger. In 10 volunteers and four patients, this method allowed the vessel to be maintained in the plane of acquisition throughout the(More)
A modified Look-Locker acquisition using saturation recovery (MLLSR) for breath-held myocardial T(1) mapping is presented. Despite its reduced dynamic range, saturation recovery enables substantially higher imaging efficiency than conventional inversion recovery T(1) mapping because it does not require time for magnetization to relax to equilibrium.(More)
A method of three-station three-dimensional magnetic resonance (MR) angiography of the lower extremities with segmented volume acquisition is presented. Three-dimensional MR angiographic data were acquired in two passes, with the central k-space views acquired during the arterial phase for the more proximal stations. This allowed a faster bolus injection(More)
The chemical shift phenomenon refers to the signal intensity alterations seen in magnetic resonance (MR) imaging that result from the inherent differences in the resonant frequencies of precessing protons. Chemical shift was first recognized as a misregistration artifact of image data. More recently, however, chemical shift has been recognized as a useful(More)