William L. Foster

Sonography of small renal masses with indeterminant density characteristics on computed tomography

Nine small renal masses with attenuation coefficients greater than 20 HU on computed tomography (CT) were termed indeterminate for cyst or renal cell carcinoma. Correlative sonography identified the fluid-filled internal architecture in four of five cysts and correctly characterized as solid four small renal cell carcinomas. The sonogram was particularly valuable in assessing masses that were indeterminate on CT when enhancement was equivocal or when intravenous contrast could not be administered. We conclude that sonography is extremely useful as a noninvasive procedure in evaluating the occasional small renal mass with CT number greater than 20 HU.

Computed tomography of high density renal cysts

Eleven patients are described whose computed tomography (CT) examinations showed homogeneous, high density (62-76 Hounsfield units) renal masses. In two patients a hemorrhagic benign cyst was found at surgery. In the remaining nine patients the constellation of CT and clinical findings supported the benign nature of this lesion.

CT appearance of lunate trachea.

Computed tomography provides excellent visualization of the trachea, but there have been only limited descriptions of variations in tracheal shape. The normal tracheal cartilage is U shaped. Lunate shaped trachea is uncommon and is characterized by a coronal/sagittal diameter ratio (tracheal index) greater than 1. We present the CT appearance of a lunate shaped trachea with corresponding pathologic sections. Destruction of the membranous septum caused marked increase in the tracheal index in this patient.

Scientific presentations. What to do and what not to do.

An effective scientific presentation requires skill, experience, and effort. In planning the presentation, a skilled speaker first forms clear conclusions through analysis of the data, then tailors the details of the proof of these conclusions to the interests and background of the audience. The facts and conclusions are presented in a practiced, specific, clear, and logical manner. It is not the topic or the data alone, but the sympathetic and strategic communication of the material to a particular audience that makes a meaningful presentation.

Somatostatinoma of the endocrine pancreas: CT findings

Somatostatinoma is the rarest of the pancreatic islet cell tumors with only eight previously reported cases. We report a recent case in a 62-year-old man including CT findings and 1 year follow-up.

CT of localized lucent lung lesions.

OCALIZED lucent lung lesions depicted by the standard chest radiograph are relatively rare, except for those occurring in patients with generalized chronic obstructive pulmonary disease. The standard chest radiograph provides an inexpensive, sensitive means for determining the presence of most clinically significant focal, thinwalled, sharply demarcated areas of avascularity. Some of the limitations of the chest radiograph in this regard are: (a) it permits only a broad differential diagnosis; (b) it sometimes does not define the full extent of disease; (c) it sometimes does not allow localization to the precise anatomic compartment; and (d) it sometimes fails to demonstrate a small accompanying lesion adjacent to or remote from the lesion under investigation. Even with these radiographic limitations, other available data including clinical history, pulmonary function studies, and laboratory results significantly enhance the radiologist’s diagnostic accuracy. For those few but potentially life-threatening localized lucent lesions, more aggressive and risky procedures must be employed for diagnostic or therapeutic purposes, such as biopsy, chest tube insertion, or even thoracotomy. With the advent of CT, considerable improvement in the overall diagnostic accuracy of these localized lucent lung lesions has been obtained. By defining more precisely the location, margins, thickness, contents, and overall configuration, CT significantly narrows the differential diagnosis. If the CT characteristics of the lesion are nondiagnostic, interventional procedures such as bronchoscopy or percutaneous aspiration biopsy can more easily be obtained by CT guidance. The CT cross-sectional display and geometric resolution sometimes more clearly define previously recognized standard radiographic features of complicated versus uncomplicated and benign versus malignant lucent lung lesions. In addition, CT uniquely distinguishes pleural from subpleural lucent lesions. Probably the most important role CT serves is in demonstrating occult opaque or lucent lesions in proximity to the original lucency or in the contralateral lung. The presence or absence of abnormal pulmonary vascularity, adenopathy, calcification, or small pleural

Emphysematous gastritis secondary to disseminated stronglyloidiasis

Emphysematous gastritis is associated with infectious gastritis produced by gas-forming organisms and with noninfectious gastric necrosis, most often secondary to corrosive ingestion. A new case of infectious emphysematous gastritis is reported secondary to disseminated stronglyoidiasis. This case is unique in that the intramural emphysema developed due to diffuse necrosis of the gastric mucosa caused by the filariform larvae ofStrongyloides stercoralis rather than by infection of the gastric wall with gasforming organisms.

Comparison of radiologists and technologists in the performance of air-contrast barium enemas.

OBJECTIVE The purpose of this study was to determine whether the rate of polyp detection and the quality of air-contrast barium enema (ACBE) procedures performed by technologists differ from those performed by radiologists. CONCLUSION Our results showed that well-trained certified technologists can perform ACBE similar in overall quality and accuracy to ACBE performed by attending physicians and residents. Training technologists to perform ACBE may help to alleviate the radiology staffing shortage in the United States.