Biomedical subjects

Marie-Pierre Revel

Publications and source records attributed to Marie-Pierre Revel.

5 recordsLinked to original sources

PubMed2006

Software volumetric evaluation of doubling times for differentiating benign versus malignant pulmonary nodules.

OBJECTIVE: The purpose of our study was to evaluate the reliability of software-calculated doubling times for discerning malignant versus benign nodules. MATERIALS AND METHODS: CT lung analysis volumetric software was used to retrospectively calculate the doubling times of 63 solid noncalcified nodules by comparing nodule volumes on baseline and follow-up CT scans obtained a median of 3.7 months apart. A final diagnosis based on validated criteria was available for all 63 nodules. All CT examinations were performed with 1.25-mm-thick slices on a four-detector unit. Taking 500 days as the upper value for malignancies, we evaluated whether the software-calculated doubling times could be used to distinguish malignant from benign solid nodules. We also examined whether the relative volume variation of benign nodules correlated with initial nodule size, interscan interval, or differences in contrast administration or exposure parameters between baseline and follow-up CT. RESULTS: There were 52 benign and 11 malignant nodules. Benign nodules had a median doubling time of 947 days and a mean relative volume variation of -4.4% (range, -50% to 38%). Malignant nodules had a median doubling time of 117 days and a mean relative volume variation of 102% (22-462%). The sensitivity, specificity, and negative and positive predictive values of the volumetric software for diagnosing malignancy were 91% (95% confidence interval [CI], 0.59-1.00), 90% (95% CI, 0.79-0.97), 98% (95% CI, 0.89-1.00), and 67% (95% CI, 0.38-0.88), respectively. No correlation was found between the relative volume variation of benign nodules and their initial size, the interscan interval, or differences in contrast administration or exposure parameters between the two CT examinations. CONCLUSION: Software-calculated pulmonary nodule doubling times of more than 500 days have a 98% negative predictive value for the diagnosis of solid malignant pulmonary nodules. This method may be useful for diagnosing malignant pulmonary nodules on follow-up CT.

Adult↗

PubMed2005

Multidetector-row computed tomography in suspected pulmonary embolism.

BACKGROUND: Single-detector-row computed tomography (CT) has a low sensitivity for pulmonary embolism and must be combined with venous-compression ultrasonography of the lower limbs. We evaluated whether the use of D-dimer measurement and multidetector-row CT, without lower-limb ultrasonography, might safely rule out pulmonary embolism. METHODS: We included 756 consecutive patients with clinically suspected pulmonary embolism from the emergency departments of three teaching hospitals and managed their cases according to a standardized sequential diagnostic strategy. All patients were followed for three months. RESULTS: Pulmonary embolism was detected in 194 of the 756 patients (26 percent). Among the 82 patients with a high clinical probability of pulmonary embolism, multidetector-row CT showed pulmonary embolism in 78, and 1 patient had proximal deep venous thrombosis and a CT scan that was negative for pulmonary embolism. Of the 674 patients without a high probability of pulmonary embolism, 232 (34 percent) had a negative D-dimer assay and an uneventful follow-up; CT showed pulmonary embolism in 109 patients. CT and ultrasonography were negative in 318 patients, of whom 3 had a definite thromboembolic event and 2 died of possible pulmonary embolism during follow-up (three-month risk of thromboembolism, 1.7 percent; 95 percent confidence interval, 0.7 to 3.9). Two patients had proximal deep venous thrombosis and a negative CT scan (risk, 0.6 percent; 95 percent confidence interval, 0.2 to 2.2). The overall three-month risk of thromboembolism in patients without pulmonary embolism would have been 1.5 percent (95 percent confidence interval, 0.8 to 3.0) if the D-dimer assay and multidetector-row CT had been the only tests used to rule out pulmonary embolism and ultrasonography had not been performed. CONCLUSIONS: Our data indicate the potential clinical use of a diagnostic strategy for ruling out pulmonary embolism on the basis of D-dimer testing and multidetector-row CT without lower-limb ultrasonography. A larger outcome study is needed before this approach can be adopted.

Aged↗

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↗

PubMed2002

Diagnostic strategy for patients with suspected pulmonary embolism: a prospective multicentre outcome study.

BACKGROUND: We designed a prospective multicentre outcome study to evaluate a diagnostic strategy based on clinical probability, spiral CT, and venous compression ultrasonography of the legs in patients with suspected pulmonary embolism (PE). The main aim was to assess the safety of withholding anticoagulant treatment in patients with low or intermediate clinical probability of PE and negative findings on spiral CT and ultrasonography. METHODS: 1041 consecutive inpatients and outpatients with suspected PE were included. Patients with negative spiral CT and ultrasonography and clinically assessed as having a low or intermediate clinical probability were left untreated. Those with high clinical probability underwent lung scanning, pulmonary angiography, or both. All patients were followed up for 3 months. FINDINGS: PE was diagnosed in 360 (34.6%) patients; 55 had positive ultrasonography despite negative spiral CT. Of 601 patients with negative spiral CT and ultrasonography, 76 were clinically assessed as having a high probability of PE; lung scanning or angiography showed PE in four (5.3% [95% CI 1.5-13.1]). The remaining 525 patients were assessed as having low or intermediate clinical probability, and 507 of them were not treated. Of these patients, nine experienced venous thromboembolism during follow-up (1.8% [0.8-3.3]). The diagnostic strategy proved inconclusive in 95 (9.1%) patients, and pulmonary angiography was done in 74 (7.1%). INTERPRETATION: Withholding of anticoagulant therapy is safe when the clinical probability of PE is assessed as low or intermediate and spiral CT and ultrasonography are negative.

Adult↗