PURPOSE To determine whether whole-brain acetazolamide-induced changes in regional cerebral blood volume (rCBV) can be assessed on a conventional gradient 1.5-T MR system using 3-D dynamic susceptibility contrast-enhanced MR imaging. METHODS A 3-D frequency-shifted (FS) burst technique was used to assess the intravascular first pass of contrast agent. Changes in rCBV were calculated in 40 vol...

Linear contrast echo configuration on the pulmonary valve M-mode echogram was assessed in 28 patients with pulmonary hypertension, in 10 with pulmonary regurgitation, and in 10 normal subjects. Contrast echo parallel lines filling the total systolic phase of the pulmonary valve were recorded in normal subjects. Contrast echo lines stopping in early systole around the pulmonary valve mid-systoli...

Pulmonary arteriovenous fistulas are rare, usually related to the Rendu-Osler-Weber syndrome, and are detected by chest CT scan or pulmonary angiography. In a 14-year-old boy without Rendu-Osler-Weber syndrome, but with clinical evidence of a right-to-left shunt, ancillary diagnostic studies were negative for pulmonary arteriovenous fistulas, and the final diagnosis was made by contrast transes...

Gradient-echo sequences are widely used in magnetic resonance imaging (MRI) for numerous applications ranging from angiography to perfusion to functional MRI. Compared with spin-echo techniques, the very short repetition times of gradient-echo methods enable very rapid 2D and 3D imaging, but also lead to complicated "steady states." Signal and contrast behavior can be described graphically and ...

PURPOSE To assess the effect of diuretic administration on the image quality of excretory magnetic resonance urography (MRU) obtained following intravenous hydration, and to determine whether intravenous hydration alone is sufficient to produce diagnostic quality studies of nondilated upper tracts. MATERIALS AND METHODS A total of 22 patients with nondilated upper tracts were evaluated with c...

PURPOSE To compare T2-weighted fat-suppressed fast spin-echo imaging with fat-suppressed conventional spin-echo imaging in the detection of normal intraorbital and pericavernous anatomy and orbital disease, and to determine the efficacy of fat saturation with T2-weighted fast spin-echo imaging of the cavernous sinus. METHODS Contrast-to-noise ratios of normal intraorbital anatomy were calcula...

PURPOSE To compare a three-dimensional Fourier transform (3DFT) gradient-echo pulse sequence with magnetization transfer at a short echo time against standard 3DFT gradient-echo technique in the evaluation of cervical spondylosis, specifically addressing the effects of motion and susceptibility artifacts on the dimensions of the neural foramina and contrast at the cerebrospinal fluid (CSF)-spin...

While echocardiography has been used to noninvasively document indirect effects on the heart of left-to-right shunting through a patent ductus arteriosus, no noninvasive technique has been developed to image the duct itself. In this study, 35 sequential studies were performed on 28 patients with a mechanical sector scanner to image the distal pulmonary artery and its bifurcation by scanning alo...