Louise Samson

Measurement of perception and interpretation skills during radiology training: utility of the script concordance approach

Imaging specialties require both perceptual and interpretation skills. Except in very simple cases, data perception and interpretation vary among clinicians. This variability makes for difficulty in measuring these skills with traditional assessment tools. The script concordance approach is conceived to allow standardized assessment in contexts of uncertainty. In this exploratory study, the authors tested the usefulness of the approach for assessment of perceptual and interpretation skills in radiology. A perception test (PT) and an interpretation test (IT) were designed according to the approach. Both tests used plain chest X-rays. Three groups were tested: clerkship students (20), junior residents (R1–R3; 20), senior residents (R4–R5; 20). Eleven certified radiologists, all currently appointed to chest reading, provided the answers by aggregate scoring method. Statistics included descriptive, ANOVA, regression analysis, Pearson and Spearman correlation coefficients. Cronbach alpha values were 0.79 and 0.81 for the PT and IT respectively. Score progression was statistically significant in both tests. Perception scores progressed more rapidly than interpretation scores during training. Effect size was large in discriminating low versus higher level of expertise, 2.2 (PT) and 1.6 (IT). The Pearson correlation coefficient between both tests was 0.58. Cronbach alpha coefficient values indicate reasonable reliability for both tests. The linear progression of scores, each at its own pace, and the positive and moderate magnitude of the Pearson correlation coefficient are arguments suggesting measurement of two different skills. More studies are necessary to document the approach usefulness for assessment in radiology training.

Pandemic Influenza A (H1N1) 2009: Chest Radiographic Findings from 147 Proven Cases in the Montreal Area

Objective To describe chest radiographic findings in patients with isolated and complicated acute novel influenza A (H1N1) virus infection. Methods Retrospective study of 147 patients (64 men, mean age 41) with reverse-transcriptase polymerase chain reaction confirmed acute influenza A (H1N1) infection, who also had a chest radiograph <72 hours of viral specimen collection. Radiographs were analysed for acute findings. A correlation with bacterial cultures results was performed. The unpaired 2-sample equal-variance Student t test was applied to continuous variables and the Pearson χ2 test of association to discrete variables. Results In 71% of cases, chest radiograph was normal. The presence of acute imaging findings was associated with older age (P < .05), increased number of comorbidities (most commonly, chronic obstructive pulmonary disease, diabetes, asthma) (P < .05), higher rate of hospitalization (P < .05) and intensive care unit admission, and increased mortality. Predominant acute radiographic finding in isolated influenza A (H1N1) was alveolar opacity (88%), either unifocal or multifocal, most often in the lower lobes. In the subgroup of patients with positive imaging findings and for whom nonviral microbiologic data was available, 62% had superimposed bacterial or fungal infection. Conclusion In the majority of patients with acute influenza A (H1N1) infection, the chest radiograph is normal. Acute imaging findings are associated with older age, an increased number of comorbidities, and a higher rate of complications and mortality. The predominant radiographic finding of isolated primary influenza A (H1N1) infection is alveolar opacity. Superimposed bacterial infection is frequent and must be excluded in patients with abnormal imaging.

Late retrograde perfusion of donor lungs does not decrease the severity of primary graft dysfunction.

BACKGROUND The ideal preservation strategy has yet to be established in lung transplantation. This clinical study compares primary graft dysfunction using antegrade and retrograde perfusion of donor lungs. METHODS Over a 6-year period, 153 consecutive patients underwent lung transplantation in our institution. Group I consists of 65 patients who received lungs preserved with an antegrade flush of modified Euro-Collins solution. Group II includes 65 patients who received lungs preserved with an antegrade flush of low-potassium dextran (LPD) solution. Group III consists of 23 patients who received lungs preserved with an antegrade and a preimplantation retrograde flush of LPD solution. Endpoints evaluated were the following: acute lung injury (ALI) score, time to achieve a fraction of inspired oxygen (Fio2) of 40% and a positive end-expiratory pressure (PEEP) of 5, length of ventilation, length of intensive care unit (ICU) stay, 90-day operative mortality, and patient survival rates. RESULTS The patient demographic data, underlying diagnosis, number of single and double lung transplants, use of cardiopulmonary bypass, and mean ischemic times were similar in all 3 groups. The mean ALI score (6.2, 5.8, and 6.0) and the median length of ventilation (23.5, 24.0, and 27.0 hours) in groups I, II, and III, respectively, were not significantly different. The length of ICU stay, the 90-day operative mortality, and the survival rates were not significantly different in the 3 groups. CONCLUSIONS Our results suggest that late retrograde perfusion of donor lungs does not decrease the severity of primary graft dysfunction when compared with standard antegrade techniques.

Chest Computed Tomography Screening in Colorectal Cancer Patients

We read with interest the article ‘‘Clinical usefulness of chest radiography in detection of pulmonary metastases after curative resection for colorectal cancer’’ that was published in the July 2007 issue of World Journal of Surgery [1]. In a retrospective analysis of patients after curative resection for colorectal cancer, the authors showed that the sensitivity of abdominal computed tomography (CT) with lower thorax images was superior to chest radiography for lung metastasis detection. They concluded that elevating the upper level of the scan during abdominal CT or performing chest CT could result in higher detection of lung metastases. As Lee et al. noted, reports evaluating CT versus radiography for detecting pulmonary metastases in the context of colorectal cancer have been few and somewhat inconsistent [2, 3]. In our center, we did a prospective study in a selected subset of 96 patients undergoing preoperative evaluation for liver metastases resection, 90% of which were from colorectal cancer, with intrapatient comparison of chest radiography and whole-chest CT for the detection of lung metastases. Neoplastic confirmation of lung lesions was done either by lung biopsy or evidence of growth on follow-up. Lung metastases were present in 13 patients (13.5%). Chest CT was more sensitive than radiography and alone prevented unnecessary liver surgery in three patients (3.1%) in whom chest radiography was normal. Four other chest CT-positive/chest radiography-negative patients were not operated on based on the nonresectability of liver lesions demonstrated by abdominal CT. In six patients, lung metastases were demonstrated by both chest CT and radiography. Incidental CT visualization of indeterminate small lung nodules (too small for characterization with biopsy or positron emission tomography) remains a potential drawback of routine chest CT for colorectal cancer in a small number of patients. Those patients require follow-up chest CT [4]. Since our prospective study, we have included chest CT in the preoperative evaluation of our patients for colorectal liver metastases resection. This is especially valuable with the wider indications of surgical resection of liver metastases allowed by the use of improved combination chemotherapy regimens [5].