Validity of CT classification on management of occult pneumothorax: a prospective study.

OBJECTIVE: In the setting of blunt trauma, abdominal CT, which routinely includes images of the lower thorax, frequently reveals pneumothoraces that have not been detected on routine supine chest radiographs. Proper management of these occult pneumothoraces remains controversial. The purpose of this study was to test the hypothesis that small (minuscule) to moderate (anterior) radiographically occult pneumothoraces can be safely managed without chest tube placement for patients in whom the need for positive pressure ventilation is not anticipated. SUBJECTS AND METHODS: We undertook a prospective study in which 44 occult pneumothoraces were classified into three groups, minuscule, anterior, or anterolateral, according to size and location on CT scans. Choice of initial management (tube thoracostomy versus close observation) was based in part on this classification system and in part on individual circumstances of a surgeon's decision. RESULTS: Of the 44 pneumothoraces found in 36 patients, 16 pneumothoraces were minuscule, 20 were anterior, and eight were anterolateral. Thirteen minuscule pneumothoraces and 11 anterior pneumothoraces initially managed with observation did not require subsequent tube thoracostomy. All eight patients with anterolateral pneumothoraces underwent tube thoracostomy. CONCLUSION: Most small (minuscule) occult pneumothoraces can successfully be managed with close observation. The risk that the pneumothorax will progress is slight. Moderate-sized (anterior) pneumothoraces may also be successfully managed without initial placement of a chest tube if the patient is not to undergo positive pressure ventilation.

Association of hiatal hernia and gastroesophageal reflux: correlation between presence and size of hiatal hernia and 24-hour pH monitoring of the esophagus.

OBJECTIVE: The relationship of hiatal hernia to gastroesophageal reflux disease remains controversial. Previous endoscopic and radiologic studies of hiatal hernia and reflux esophagitis have shown that hiatal hernia is a poor predictor of the presence of endoscopic esophagitis, especially for smaller hernias. Similar correlations with 24-hr pH monitoring have not been done. The purpose of this study was to determine if there is a correlation between the presence and size of hiatal hernias and gastroesophageal reflux using 24-hr pH monitoring as a measure of the degree of reflux. MATERIALS AND METHODS: We reviewed the barium esophagograms and the results of pH monitoring of the esophagus in 319 patients (161 women and 158 men; mean age, 51 years). The presence and size of hiatal hernia were determined from the radiographic examination; size was categorized as "minimal" or "larger" (> or = 2 cm axial length). An abnormal result of pH monitoring was defined as a pH less than 4 for 6% or more of the 24-hr observation time. RESULTS: Abnormal results of pH monitoring were found in 61 (31%) of 199 patients with hiatal hernia compared with 21 (18%) of 120 patients without hiatal hernia (p < .05). Abnormal findings of pH monitoring were present in 33 (35%) of 95 patients with a larger hiatal hernia versus 28 (27%) of 104 patients with a minimal hiatal hernia (p > .05); a significant difference (p < .05) was observed when patients without hiatal hernia were compared with those with a larger hiatal hernia. CONCLUSION: Most patients in this study had normal results of pH monitoring of the esophagus regardless of the presence or absence of hiatal hernia. However, patients with larger hiatal hernias were more likely to have abnormal findings on pH monitoring; hiatal hernias of minimal size were a poorer predictor of the presence of abnormal gastroesophageal reflux.

Ultrasonography: usefulness in localization of the Norplant contraceptive implant system.

Norplant is a levonorgestrel-containing contraceptive system that consists of six small capsules (2.4 x 34 mm), which are placed subdermally. Owing to the relative newness of this contraceptive modality, problems with removal of the Norplant implants are just beginning to be reported; these consist primarily of inability to locate and remove all six implant capsules upon discontinuation. Ultrasonographic images of 14 women with the Norplant system in place were obtained in the axial and longitudinal planes. On axial view the capsules consisted of discrete circular individual areas of high echogenicity with prominent posterior shadowing. Capsules scanned in a longitudinal plane demonstrated echogenicity of the superior and inferior capsular walls, giving a tubular appearance. It was possible to demonstrate the depth of capsule placement, spatial relation to surrounding capsules, and orientation in relation to the skin surface. Ultrasonography therefore may provide a useful, noninvasive method for localization of nonpalpable Norplant implants, thus facilitating removal.

Residency and fellowship training in radiology: survey of all United States programs.

RATIONALE AND OBJECTIVES: We surveyed radiology training programs to determine current requirements for a clinical internship year, recent changes in the clinical internship requirement, current number of residents, percentage of residents with preradiology clinical experience, number of current first-year fellows, and percentage of residents entering fellowships. METHODS: Survey forms were sent to all 208 U.S. diagnostic radiology programs and were followed up by telephone and facsimile transmission. RESULTS: Survey response rate was 100%. One hundred programs (48%) require an internship, whereas 108 programs (52%) do not. Of programs without a clinical internship requirement, 33 (31%) have eliminated this requirement within the last 5 years. The clinical year requirement varied greatly by region. A total of 3983 residents are training at present, and 29% did not complete a clinical internship. Currently, 650 fellows are in training. Approximately 68% of graduating residents are entering fellowships. CONCLUSIONS: Many residency programs have recently discontinued the clinical internship year requirement. Changes in Medicare reimbursement of resident salaries may be one factor promoting this change. During the past 4 years, the number of radiology residents training per year has increased. The percentage of residents entering radiology without an internship year has increased by 6% during the past 4 years. An increasing number of graduating residents are entering fellowships.

In vitro stability of an unconstrained total elbow prosthesis. Influence of axial loading and joint flexion angle.

Total elbow arthroplasty is often used to replace elbow joints that have been severely damaged by arthritis or trauma. A great disparity of designs exists, however, in currently available elbow prostheses. This study evaluated the intrinsic stability of one popular resurfacing implant, the Capitellocondylar (Johnson and Johnson Orthopaedics, Inc., New Brunswick, NJ) total elbow. The in vitro response of this unconstrained prosthesis to valgus-varus and supination-pronation loading was investigated using a materials testing machine. The influence of compressive loading and flexion angle on the intrinsic stability of the prosthesis was studied. The Capitellocondylar prosthesis was found to have little intrinsic constraint, relying on external forces for component stabilization. Dislocations were common at 111 N of compressive loading, while larger loads progressively stabilized the prosthesis. Joint flexion angle had little influence on the intrinsic constraint of the implant except to increase varus stability at lower flexion angles. The Capitellocondylar total elbow prosthesis, as designed by F. C. Ewald, behaves as an unconstrained implant. Adequate soft tissue supports, which are properly balanced to provide controlled loading, are essential to prevent instability of this arthroplasty.