Focused transcranial ultrasound for treatment of neurodegenerative dementia.

Introduction: Preclinical studies support investigation of focused ultrasound for breakdown of cerebral pathologies in neurodegenerative conditions including Alzheimer's disease (AD) and Parkinson's disease (PD).

Methods: A focused transcranial Doppler device with probes (2 MHz, 520 mW/cm) affixed bilaterally was used to target the hippocampus (AD) or substantia nigra (PD) with functional magnetic resonance imaging navigation for enhanced plaque removal. A total of 22 patients (n = 11 AD, n = 11 PD) underwent 8 consecutive, weekly, 1-hour treatments wherein sleep was encouraged naturally or pharmacologically.

Non-invasive cardiac evaluation in heart failure patients using magnetic resonance imaging: a feasibility study.

Background: To assess the feasibility of a fast, flow-insensitive magnetic resonance imaging (MRI) protocol in heart failure patients for the evaluation of cardiac function, cardiovascular anatomy, and myocardial viability.

Methods And Results: Thirty-two consecutive patients with left ventricular (LV) systolic dysfunction and 13 control subjects were prospectively evaluated with MRI. The exam consisted of cine imaging with a steady-state free precession sequence, followed by time-resolved, three-dimensional angiography and delayed, contrast-enhanced imaging.

High-resolution breath-hold contrast-enhanced MR angiography of the entire carotid circulation.

Objective: The purpose of this study was to evaluate the effect of breathing on image quality of the aortic arch and carotid vessels during contrast-enhanced MR angiography and to show that high-resolution breath-hold contrast-enhanced MR angiography combined with a timing-bolus technique can produce high-quality images of the entire carotid circulation.

Materials And Methods: Forty patients underwent high-resolution contrast-enhanced MR angiography on a 1.5-T Magnetom Symphony.

Cine MR angiography of the heart with segmented true fast imaging with steady-state precession.

In five healthy subjects and 18 patients, cine magnetic resonance (MR) imaging of the heart was performed with a true fast imaging with steady-state precession (FISP) sequence. Results were compared both quantitatively and qualitatively with those at cine fast low-angle shot (FLASH) MR imaging. The blood-myocardial contrast-to-noise ratio (CNR) was 2.

Comparison of conventional and computed radiography: assessment of image quality and reader performance in skeletal extremity trauma.

Rationale And Objectives: Reader performance and image quality wee assessed for standard film, computed film, and computer monitor radiography viewing formats in the evaluation of skeletal extremity trauma.

Materials And Methods: Three radiologists and three orthopedic surgeons interpreted 27 skeletal radiographs obtained with equivalent technical parameters. Readers evaluated standard film, computed film, and computer monitor formats randomly for fracture and soft-tissue abnormalities.

Gender influences on earnings of obstetrician-gynecologists.

Objective: To test the hypothesis that the observed difference in earnings between male and female obstetrician-gynecologists could be explained by variations in productivity and human capital.

Methods: Data from a 1991 national survey of ACOG Fellows were used to provide a descriptive analysis of male and female obstetrician-gynecologists' demographic characteristics, net income, experience, practice characteristics, workload, and practice activities. Variables found to have a significant impact on net income or to vary significantly by sex were included in a multiple regression analysis.