Chest Radiography with a Flat-Panel Detector: Image Quality with Dose Reduction after Copper Filtration
| Autor: | Stefan Feuerbach, I. Borisch, Claude B. Sirlin, Michael Strotzer, Okka W. Hamer, Niels Zorger, Markus Völk |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Male
Thorax Silicon medicine.medical_specialty Image quality Radiography Cesium chemistry.chemical_element Image processing Radiation Dosage Statistics Nonparametric Flat panel detector law.invention law Image Processing Computer-Assisted medicine Humans X-Ray Intensifying Screens Radiology Nuclear Medicine and imaging Prospective Studies Filtration Retrospective Studies Phantoms Imaging business.industry Detector Iodides Middle Aged Copper Radiographic Image Enhancement Logistic Models chemistry Female Radiography Thoracic Radiology business Nuclear medicine Monte Carlo Method |
| Zdroj: | Radiology. 237:691-700 |
| ISSN: | 1527-1315 0033-8419 |
| DOI: | 10.1148/radiol.2372041738 |
| Popis: | To compare image quality and estimated dose for chest radiographs obtained by using a cesium iodide-amorphous silicon flat-panel detector at fixed tube voltage and detector entrance dose with and without additional 0.3-mm copper filtration.The study was approved by the institutional ethics committee. All prospectively enrolled patients signed the written consent form. Chest radiographs in two projections were acquired at 125-kVp tube voltage and 2.5-microGy detector entrance dose. The experimental group (38 patients) was imaged with 0.3-mm copper filtration; the control group (38 patients) was imaged without copper filtration. An additional 12 patients were imaged with and without copper filtration and served as paired subject-controls. Three readers blinded to group and clinical data independently evaluated the radiographs for image quality on a digital display system. Twelve variables (six for each radiographic projection) were assigned scores on a seven-point ordinal scale. Scores between experimental and control groups were compared: Logistic regression analysis and Mann-Whitney U test were used for unpaired patients; and Wilcoxon and McNemar test, for paired patients. In all, 72 comparisons were determined (36 [12 variables x three readers] for unpaired patients and 36 for paired patients). In a phantom study, radiation burden of experimental protocol was compared with that of control protocol by using Monte Carlo calculations.For 70 of 72 comparisons, digital radiographs obtained with copper filtration were of similar image quality as radiographs obtained without copper filtration (P = .123 to P.99). For two of 72 comparisons, one observer judged the experimental protocol superior to the control protocol (P = .043, P = .046). Patient dose reduction estimated with Monte Carlo calculations was 31%. Use of copper filtration increased exposure times by 48% for posteroanterior views and by 34% for lateral views.Subjectively equivalent chest radiographic image quality was found with estimated 30% dose reduction after addition of 0.3-mm copper filtration with flat-panel cesium iodide-amorphous silicon technology. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|