Respiration artifacts in MR imaging: reduction by breath holding

Respiratory motion commonly produces degradation of image quality on magnetic resonance scans of the upper abdomen due to artifacts produced in the direction of the phase encoding gradient. Such artifacts may be reduced, although not eliminated, on image sequences obtained with relatively short acquisition times by means of breath holding during the middle 20% of the sequence.     

New tool for presenting risk in obstetrics and gynecology

BACKGROUND: The Paling Perspective Scale, a means of communicating risk in various settings, has been applied to diverse fields such as nuclear power, blood banking, and ophthalmology. TECHNIQUE: Statistics of risk for various events in obstetrics and gynecology were collected from the literature and directly applied to the risk scale. EXPERIENCE: The graphic simplicity and versatility of this scale make it adaptable for communicating risks to people of different technical and educational backgrounds. CONCLUSION: The Paling Perspective Scale might help obstetrician-gynecologists obtain informed consent for surgery, genetic counseling, and other topics.     

Quantitation of the prominent medullary pyramid: a reappraisal

We propose a revised objective measurement of the size of the renal medullary pyramid in the assessment of the prominent renal pyramid: the medullary-renal ratio (MRR). (Formula: see text). This is a more accurate assessment of the size of the renal pyramid relative to the size of the kidney than the previously proposed medullary pyramid index, which fails to take into account the varying morphology of otherwise normal kidneys.     

Patterns of cerebral atrophy in dementia with Lewy bodies using voxel-based morphometry

Previous cross-sectional MRI studies based on region-of-interest analyses have shown that increased cerebral atrophy is a feature of both Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Relative preservation of the hippocampus and temporal lobe structures in DLB compared to AD has been reported in region-of-interest-based studies. Recently, image processing techniques such as voxel-based morphometry (VBM) have been developed to provide an unbiased, visually informative, and comprehensive means of studying patterns of cerebral atrophy. We report the first study to use the voxel-based approach to assess patterns of cerebral atrophy in DLB compared to control subjects and AD. Regional gray matter volume loss was observed bilaterally in the temporal and frontal lobes and insular cortex of patients with DLB compared to control subjects. Comparison of dementia groups showed preservation of the medial temporal lobe, hippocampus, and amygdala in DLB relative to AD. Significant gray matter loss was also observed in the thalamus of AD patients compared to DLB.     

Computerized tomographic appearance of renal cysts after extracorporeal shock wave lithotripsy

We identified cysts in five kidneys of four patients who had lithotripsy. Three of these kidneys were evaluated with CT scans the day before and the day after lithotripsy and showed no change. The other two kidneys were studied by CT only after extracorporeal shock wave lithotripsy; hemorrhage was shown in one and cyst wall thickening in the other.