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W Laster

Publications and source records attributed to W Laster.

5 recordsLinked to original sources

Magnetic resonance imaging of the paranasal sinuses: frequency and type of abnormalities.

This retrospective study reports on sinus abnormalities detected in patients having magnetic resonance imaging (MRI) scans. Over a 12-month period, 1120 patients (aged 2-87 years) had MRI scans done for suspected intracranial pathology. Scans were reviewed independently for abnormal sinuses using four criteria: increased signal of the epithelial lining, cloudy or opacified sinus cavity, air-fluid levels, and intrasinus polyps. Thirteen percent of the 1120 patients had abnormal sinus images with the maxillary being the most involved cavity. A cloudy or opacified sinus was found in 43% of these cases. An increased signal to the epithelial lining was present in 44%. Intrasinus polyps were found in 27 paranasal sinus cavities (27 subjects). Furthermore, a seasonal pattern was evident for abnormal sinus scans. The months of July, August, September, and December had the highest frequency of abnormalities noted (greater than 16% of total scans done) whereas there was a low percentage (less than 8%) found during February and November. In summary, abnormalities of the paranasal sinuses occur frequently and vary with the time of year.

Adolescent

The trapped temporal horn: a trap in neuroradiological diagnosis.

Although the advent of computerized cranial tomography (CT) has decreased the number of pneumoencephalograms performed for the diagnosis of hydrocephalus and lesions of the posterior fossa, brain stem, and ventricles, there are some patients in whom pneumoencephalography should still be done because it adds valuable information to that obtained with CT. When the temporal horn becomes obstructed, the choroid plexus and ependymal surface "upstream" from the obstructing mass continue to produce cerebrospinal fluid (CSF). The temporal horn can thus enlarge enough to appear as a mass on CT because of its reduced x-ray attenuation coefficient. Pneumoencephalography is effective in this situation because air will flow past a mass that obstructs CSF and because the ventricular system dilates during pneumoencephalography. When pneumoencephalography is used in a patient with a trapped temporal horn, the partially trapped horn may enlarge approximately 24 hours later. With that precaution in mind, the neurosurgeon should find pneumoencephalography to be a useful adjunct to CT in delineating the cause of a trapped temporal horn. In the three patients reported here CT had indicated a unilateral trapped temporal horn; pneumoencephalography confirmed that finding and demonstrated both the location and the nature of the lesion. One patient had a Grade II astrocytoma fungating into the atrium of the right lateral ventricle, one had a mass extending into the right ventricle from the medial and superior ventricular wall with nodular encroachment on the ventricle, and one had a meningioma in the atrium of the right lateral ventricle.

Aged