Jeffrey R. Crass

Rounded atelectasis and fibrotic pleural disease: the pathologic continuum

Although rounded atelectasis was recognized in 1928, its relationship to fibrotic pleural disease almost has gone unnoticed. We present four cases of lobar rounded atelectasis that help to clarify this relationship. Rounded atelectasis is part of the spectrum of fibrous pleural disease. Any portion of lung may become entrapped by the pleural process. When focal areas are involved rounded atelectasis results. When a larger portion of the thorax is involved with this process, lobar rounded atelectasis may occur. Very extensive disease is recognized as fibrothorax.

Hyperlucent Thorax from Rotation: Anatomic Basis

Crass JR, Cohen AM, Wiesen E, Shah Z. Hyperlucent thorax from rotation: anatomic basis. Invest Radiol 1993;28:567-572. RATIONALE AND OBJECTIVES.The authors studied a large group of patients with a computed tomography (CT)-based model to evaluate the presence, significance, and anatomic basis of unilateral hyperlucency from patient rotation. METHODS.Chest CT sections at three levels in 65 consecutive patients undergoing routine diagnostic studies were read into a microcomputer. Radiographic transmittance data were calculated across each CT section at different degrees of rotation as well as for lateral decentering. Data were analyzed for the pattern of density variation both individually as well as in stratified subgroups. RESULTS.The data showed a trend of increasing radiographic transmission on the side opposite that of the anterior obliquity. The resulting optical density difference was small and was not clinically significant. Lateral decentering produced smaller changes than rotation. The anterior breast/ pectoral structures are the etiology for the phenomenon. Optical density differences of 0.1 result from a difference in tissue thickness of 4 mm. CONCLUSIONS.The changes in radiographic transmission with rotation are small and are overshadowed by soft tissue compression. Rotation alone will result in decreased radiographic transmission on the side of anterior obliquity; thus, the left side will be more lucent in an right anterior oblique projection.

Gastroschisis : prenatal CT diagnosis

The prenatal sonographic findings of gastroschisis are well defined. This report describes the CT appearance of fetal gastroschisis discovered as an incidental finding when a 25-year-old pregnant woman underwent CT for blunt abdominal trauma.