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Catherine Lefort

Publications and source records attributed to Catherine Lefort.

4 recordsLinked to original sources
PubMed2005

Diagnosing pulmonary embolism with four-detector row helical CT: prospective evaluation of 216 outpatients and inpatients.

PURPOSE: To prospectively evaluate multi-detector row helical computed tomography (CT) for the diagnosis of pulmonary embolism (PE), with focus on the proportion of diagnostic studies and frequency of subsegmental and chronic PE. MATERIALS AND METHODS: Institutional review board approval and patient consent were not required. A total of 220 consecutive CT angiography studies, 124 (56%) of which involved inpatients, were assessed. Thoracic CT angiography was performed in 216 patients; there were 101 male (age range, 25-93 years; median, 66 years) and 115 female (age range, 15-98 years; median, 67 years) patients. Contiguous 1.25-mm sections were acquired through the entire thorax after injection of 140 mL of contrast material at a rate of 4 mL/sec. CT venography was combined with thoracic CT angiography in 178 patients over 40 years of age. CT studies were interpreted first in the emergency setting and subsequently by two experienced chest radiologists. Untreated patients with normal results were contacted by telephone after 3 months. Proportions were compared with the chi(2) test, and agreement was assessed by calculating the kappa statistic (for thoracic CT angiography). RESULTS: Concordance between the two reading sessions was good (kappa = 0.88; 95% confidence interval: 0.77, 0.98). The proportion of nondiagnostic thoracic CT angiography studies was 9% (20 of 220). PE was found in 54 (24.5%) of 220 cases; eight (15%) of 54 patients had only subsegmental PE, which was associated with a calf vein thrombosis in two patients, and six patients (11%) had chronic PE. CT venography demonstrated venous thrombosis in 15% (26 of 178) of the patients thus studied, as well as in 45% (21 of 47) of patients with positive results at thoracic CT angiography and 4% (five of 131) of patients with negative results at thoracic CT angiography. The 3-month rate of thromboembolic events after negative results was 1.8% (two of 111) (95% confidence interval: 0.2%, 6.4%). CONCLUSION: Multi-detector row CT enables diagnosis in 91% of cases and identification of isolated subsegmental or chronic PE in a relatively high proportion of patients.

Adult↗
PubMed2004

Are two-dimensional CT measurements of small noncalcified pulmonary nodules reliable?

PURPOSE: To evaluate the intra- and interreader agreement of two-dimensional computed tomographic (CT) measurements of pulmonary nodules less than 2 cm in diameter. MATERIALS AND METHODS: Three readers independently made three serial measurements of each of 54 pulmonary nodules measuring 3-18 mm that had been observed on standard-dose multisection CT images obtained in 24 patients who ranged in age from 36 to 81 years (mean age, 54.6 years). There were 14 women (58%), who ranged in age from 43 to 81 years (mean age, 58.9 years), and 10 men (42%), who ranged in age from 36 to 65 years (mean age, 48.5 years). The largest transverse cross-sectional diameter of each nodule was measured at picture archiving and communication system, or PACS, workstations by using high-spatial-resolution reconstructed CT images and identical window settings. Intra- and interreader agreement were determined by using methods described by Bland and Altman: the coefficient of repeatability for intrareader agreement, and methods derived from the 95% limits of agreement defined by Bland and Altman for interreader agreement. RESULTS: The repeatability coefficients were 1.70, 1.32, and 1.51 mm for readers 1, 2, and 3, respectively. The 95% limits of agreement for the difference among readers were -1.73 and 1.73. CONCLUSION: Two-dimensional CT measurements are not reliable in the evaluation of small noncalcified pulmonary nodules.

Adult↗
PubMed2004

Pulmonary nodules: preliminary experience with three-dimensional evaluation.

PURPOSE: To evaluate software designed to calculate pulmonary nodule volume in three dimensions. MATERIALS AND METHODS: Fifty-four solid noncalcified pulmonary nodules measuring 5-18 mm in diameter were studied with computed tomographic (CT) volumetric software. Baseline CT examinations were performed for various indications by using four-detector row multisection CT units, 1.25- or 2.50-mm sections, and a standard reconstruction algorithm. The percentage of successful nodule segmentations, as well as intraobserver variability, interreader agreement, and global repeatability of calculated volumes, was determined on the basis of consecutive measurements performed three times by three different radiologists by using the Bland and Altman method. The software was used to calculate the doubling time of 22 nodules for which a final diagnosis and comparable CT scans were available. RESULTS: Fifty-two (96%) of the 54 nodules were successfully segmented, allowing their volume to be calculated. Repeatability was high: There was no variation in the nine measurements of 35 (67%) of the 52 nodules. The coefficient of variation for the remaining 17 nodules (33%) was 2.26%. Bland and Altman 95% limits of acceptability, calculated on the basis of log-transformed data, yielded a maximum software measurement error of 6.38% of the previous volume measurement. Doubling time ranged from 4 to 188 years for the 13 benign nodules and from 37 to 216 days for the nine malignant nodules. CONCLUSION: Software volumetric analysis yielded repeatable estimates for 96% of the nodules examined. All software-calculated doubling times were in keeping with the benign or malignant nature of the nodules.

Adult↗