Value of spiral CT in hemodynamically stable patients following blunt chest trauma

Introduction: Features of spiral CT (SCT) — fast scanning, dynamic injection of contrast allowing optimal vessel opacification, and supplemental multiplanar imaging — promises to provide increased accuracy in the diagnosis of acute and non acute thoracic vascular disease. Recent work demonstrating the cost effective triage of hemodynamically stable patients after blunt chest trauma for angiography based on dynamic CT findings has prompted an investigation into the accuracy of SCT in this clinical setting. Methods: A retrospective review of all patients seen in the emergency department over the period of one year for aortic, thoracic, or blunt chest trauma evaluation was performed (74 patients) and all SCT scans available were reviewed and data reformatted for optimal delineation of pathology using maximum intensity projection and multiplanar reformation. The accuracy and predictive positive and negative values of SCT were calculated with respect to angiography, surgical, and/or clinical follow up evaluation. Results: Twenty three (31%) patients went directly to angiography owing to mediastinal widening on chest film and hemodynamic instability, of which four were positive and required emergent surgery. Seven hemodynamically stable patients (9%) had noncontrast SCT owing to mediastinal widening on chest film, all of which had angiography with none having great vessel trauma. Fourty four hemodynamically stable patients (60%) had contrast enhanced SCT (ceSCT), of which five (11%) were abnormal and underwent angiography, four of these were positive for aortic damage, one for a subclavian artery laceration. Of the remaining 39 patients who had normal ceSCT; five had angiography, all of which were normal. Of the remaining 34 patients that had normal ceSCT none had adverse outcome on clinical follow-up, minimum of 12 months. Conclusion: The predictive positive value for aortic trauma of ceSCT in blunt trauma is 80%, with a predictive negative value of 100%, indicating that it is feasible for SCT to be a first line exam in blunt chest trauma in the future.     

Expression of Hedgehog ligand and signal transduction components in mutually distinct isocitrate dehydrogenase mutant glioma cells supports a role for paracrine signaling

DNA methylation plays an important role in cancer biology and methylation events are important prognostic and predictive markers in many tumor types. We have used methylation-specific multiplex ligation-dependent probe amplification to survey the methylation status of MGMT and 25 tumor suppressor genes in 73 glioblastoma cases. The data obtained was correlated with overall survival and response to treatment. The study revealed that methylation of promoter regions in TP73 (seven patients), THBS1 (eight patients) and PYCARD (nine patients) was associated with improved outcome, whereas GATA5 (21 patients) and WT1 (24 patients) promoter methylation were associated with poor outcome. In patients treated with temozolomide and radiation MGMT and PYCARD promoter methylation events remained associated with improved survival whereas GATA5 was associated with a poor outcome. The identification of GATA5 promoter methylation in glioblastoma has not previously been reported. Furthermore, a cumulative methylation score separated patients into survival groups better than any single methylation event. In conclusion, we have identified specific methylation events associated with patient outcome and treatment response in glioblastoma, and these may be of functional and predictive/prognostic significance. This study therefore provides novel candidates and approaches for future prospective validation.     

The Incentive Dilemma: Intrinsic Motivation and Workplace Performance

Incentive plans are a core component of many radiology positions and are often considered a major factor in the ability to recruit and retain high-performing radiologists. Financial incentives are widely thought to be effective at motivating individuals, but there is considerable evidence to the contrary. In this report, the authors examine basic assumptions about financial incentives and debate the potential negative impact of financial incentive systems on performance at radiology practices.     

The impact of ultrasound examinations on the management of children with suspected appendicitis: a 3-year analysis

BACKGROUND/PURPOSE: The aim of this study was to evaluate the usefulness of ultrasonography in the routine management of children with suspected appendicitis in a children's hospital. METHODS: Data from surgical, radiologic, and pathologic databases were cross referenced retrospectively to allow for review of all children undergoing appendectomy and all children undergoing an ultrasound scan to rule out appendicitis in the 3-year period August 1, 1996 to July 31, 1999. RESULTS: Pathology reports were available for 1,007 of 1,032 patients undergoing appendectomy. Eighty-four percent had acute appendicitis (26% of these were perforated). Fifty-eight percent of all children undergoing appendectomy had at least 1 preoperative ultrasound scan. Eighty-six percent of those having ultrasound scans had acute appendicitis compared with 82% of those who did not have an ultrasound scan (P <.05 chi(2) Test). During the same period, 2,056 ultrasound examinations were performed by staff radiologists who were available 24 hours a day to rule out appendicitis. Ultrasonography in this setting had a sensitivity of 89%, specificity of 95%, positive predictive value of 86%, and a negative predictive value of 96% (true-positives, n = 496; false-positive, n = 81; true-negative, n = 1,417; false-negative, n = 62). An alternate ultrasound diagnosis was offered in 157 children. CONCLUSIONS: Ultrasound scan improves diagnostic accuracy in children with suspected appendicitis. The high negative predictive value of ultrasound scan, especially when used repeatedly, may reduce the need for admission to hospital for clinical observation to rule out appendicitis.     

Radiation injury to the liver after intensity-modulated radiation therapy in patients with mesothelioma: an unusual CT appearance

OBJECTIVE: We sought to report the unusual distribution of radiation-induced injury to the liver in patients with mesothelioma after extrapleural pneumonectomy and intensity-modulated radiation therapy (IMRT). CONCLUSION: Abnormal hepatic enhancement after extrapleural pneumonectomy and IMRT is common in patients with mesothelioma. Knowledge of the early occurrence and typical location and appearance of IMRT-induced injury can be useful in preventing misinterpretation as metastatic disease or recurrent tumor.     

Focal FDG uptake in mediastinal brown fat mimicking malignancy: a potential pitfall resolved on PET/CT

OBJECTIVE: A potential source of false-positive FDG PET interpretations in oncologic imaging is FDG uptake in brown fat. The purpose of this study was to determine the prevalence, location, and appearance of hypermetabolic brown fat in the mediastinum. MATERIALS AND METHODS: All PET/CT scans obtained at our cancer institution from August to October 2003 were retrospectively reviewed for increased FDG uptake in the mediastinum localized to fat on CT. The following features were recorded: location, appearance, maximal standard uptake value (SUV(max)) of hypermetabolic mediastinal brown fat, and presence of extramediastinal brown fat. RESULTS: PET/CT scans were obtained in 845 oncologic patients. Fifteen patients (1.8%) with focal hypermetabolic mediastinal brown fat were identified: nine women and two men (age range, 27-79; mean, 55.1 years) and four children (age range, 5-16 years; mean, 10 years). Hypermetabolic mediastinal brown fat (mean SUV(max), 5.7) was more common in children (4/8) than in adults (11/837) and more common in women (9/372) than in men (2/465). Foci of hypermetabolic brown fat were localized to the paratracheal, paraesophageal, prevascular, and pericardial regions; interatrial septum; and azygoesophageal recess. Five patients had focal hypermetabolic brown fat isolated to the mediastinum. Ten patients also had extramediastinal hypermetabolic brown fat in the neck, thorax, and abdomen. There was no difference in the body weight (p = 0.876) or body mass index (p = 0.538) of patients with hypermetabolic brown fat compared with age- and sex-matched control subjects. CONCLUSION: Hypermetabolic brown fat can be localized to the mediastinum and manifests as focal increased FDG uptake. Knowledge of this potential pitfall and precise localization with fusion PET/CT are important in preventing misinterpretation as malignancy.