共查询到20条相似文献,搜索用时 0 毫秒
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Kido S Kuriyama K Kuroda C Nakamura H Ito W Shimura K Kato H 《European journal of radiology》2002,44(3):205-209
OBJECTIVE: To evaluate the performance of the computer-aided diagnosis (CAD) scheme on the detection of pulmonary nodules (PNs) in single-exposure dual-energy subtraction computed radiography (CR) images of the chest, and to evaluate the effect of this CAD scheme on radiologists' detectibilaties. METHODS AND MATERIAL: We compared the detectability by the CAD scheme with the detectability by 12 observers by using conventional CR (C-CR) and bone-subtracted CR (BS-CR) images of 25 chest phantoms with a low-contrast nylon nodule. RESULTS: Both in the CAD scheme and for the observers, the detectability of BS-CR images was superior to that of C-CR images (P<0.005). The detection performance of the CAD scheme was equal to that of the observers. The nodules detected by the CAD did not necessarily coincide with those by the observers. Thus, if observers can use the results of the CAD system as a 'second opinion', their detectabilities increase. CONCLUSION: The CAD system for detection of PNs in the single-exposure dual-energy subtraction method is promising for improving radiologists' detectabilities of PNs. 相似文献
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Detection of lung cancer using single-exposure dual-energy subtraction chest radiography 总被引:1,自引:0,他引:1
PURPOSE: The aim of this study was to evaluate the detectability of lung cancer by chest radiography with a single-exposure dual-energy subtraction (ES) method. MATERIALS AND METHODS: Five radiologists read two sets of chest radiographs from 77 patients (66.5 +/- 9.6 years old) with histologically proven lung cancer measuring or=50 but <100%; (3) solid: TDR was <50%. RESULTS: Overall, detectability with the ES method was significantly better than that without ES (mean Az value increased from 0.7673 to 0.8265, P < 0.05). In the subgroup analysis of the nonsolid group and the solid group detectability did not change using the ES method, whereas in the partly solid group detectability with the ES method was significantly better than that without ES (mean Az value increased from 0.7162 to 0.8209, P < 0.005). CONCLUSION: The ES method improves the detectability of lung cancer by chest radiography, especially of the partly solid group. 相似文献
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Clinical evaluation of pulmonary nodules with dual-exposure dual-energy subtraction chest radiography 总被引:5,自引:0,他引:5
Uemura M Miyagawa M Yasuhara Y Murakami T Ikura H Sakamoto K Tagashira H Arakawa K Mochizuki T 《Radiation Medicine》2005,23(6):391-397
PURPOSE: The purpose of this study was to assess the effect of dual-exposure dual-energy (DE) subtraction chest radiography with flat-panel detector. MATERIALS AND METHODS: One hundred patients underwent dual-exposure DE subtraction chest radiography and chest CT for evaluation of pulmonary nodules. Fifty-two patients with pulmonary nodules and 48 patients with normal lungs were selected for receiver operating characteristic (ROC) curve analysis. Ten radiologists who were unaware of the CT results evaluated chest radiography alone and chest radiography with DE subtraction images in the detection of pulmonary nodules. For each radiologist, we calculated the areas under the ROC curve (Az) for chest radiography alone and chest radiography with DE subtraction images. RESULTS: The average detectability of dual-exposure DE subtraction chest radiography was statistically significantly higher than that of chest radiography without subtraction images (mean Az value increased from 0.784 to 0.815, p<0.001). CONCLUSION: Dual-exposure DE subtraction chest radiography improves diagnostic accuracy of pulmonary nodules. 相似文献
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Fraser RG; Hickey NM; Niklason LT; Sabbagh EA; Luna RF; Alexander CB; Robinson CA; Katzenstein AL; Barnes GT 《Radiology》1986,160(3):595-601
The authors undertook a clinical study to determine the accuracy of dual-energy digital radiography in revealing nodule calcification because calcification in a pulmonary nodule almost excludes the possibility of malignancy. Over a 6-month period, 61 patients with pulmonary nodules (less than or equal to 3 cm) or masses (greater than 3 cm) were examined on a prototype scanned projection unit using a dual-energy detector. In 49 of 61 patients, nodules were noncalcified, and in 12, they were calcified. In 57 patients, the benignancy or malignancy of nodules was established beyond reasonable doubt by pathologic confirmation in 38 and by strong inference in 19 (four patients with noncalcified solitary pulmonary nodules either refused further investigation or surgery or their follow-up was too short to permit exclusion of malignancy). Dual-energy radiography was found to be highly accurate in assessing the presence or absence of calcification in pulmonary nodules and thus in determining their benignancy or possible malignancy. 相似文献
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Uozumi T Nakamura K Takahashi H Okazaki H Kamada K Kakeda S Nakata H Oda N Katsuragawa S Doi K 《Nihon Igaku Hōshasen Gakkai zasshi. Nippon acta radiologica》2000,60(4):193-198
Temporal subtraction is a technique by which a previous chest radiograph is subtracted from a current radiograph in order to enhance interval changes. Our purpose in this study was to evaluate the usefulness of temporal subtraction for the detection of metastatic pulmonary nodules. We examined 19 cases of metastatic nodules less than 15 mm in diameter (8.4 mm on average). Temporal subtraction images were created based on the matching of local lung areas in pairs of chest radiographs. By using the subtraction images, the detectability of nodules was clearly improved in 5 cases and moderately improved in 8 cases; there was no improvement in 6 cases. The subtraction images were especially useful for nodules superimposed over normal structures, such as rib, mediastinum, and diaphragm, as well as for small nodules. In 6 of the 19 cases, the nodules had been missed clinically; however, the temporal subtraction images clearly demonstrated half of missed small nodules. Temporal subtraction made it possible to enhance subtle interval changes and helped in detecting small pulmonary metastases. This technique seems promising for augmenting the capabilities of computed radiography of the chest. 相似文献
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Simulated pulmonary nodules: detection with dual-energy digital versus conventional radiography 总被引:9,自引:0,他引:9
Niklason LT; Hickey NM; Chakraborty DP; Sabbagh EA; Yester MV; Fraser RG; Barnes GT 《Radiology》1986,160(3):589-593
Performance of a prototype dual-energy digital chest radiography unit in detecting calcified and noncalcified simulated pulmonary nodules was compared with that of a highly optimized, conventional system. Nodules ranging in size (0.5, 1.0, and 1.6 cm), in number (five to 11), and in calcium content (0-25 mg) were superimposed over the lungs of a frozen, unembalmed, human chest phantom. For each technique, six observers examined 50 posteroanterior projections with different randomized nodule locations. Detection consisted of locating and assigning a level of confidence to each perceived nodular opacity. The resulting plots of the true-positive fraction versus the mean number of false-positive calls per projection indicate that for both calcified and noncalcified nodules, the digital unit performed significantly better (P less than .01). 相似文献
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Single-exposure dual-energy subtraction chest radiography: Detection of pulmonary nodules and masses in clinical practice 总被引:1,自引:0,他引:1
The purpose of this retrospective study was to evaluate the impact of energy subtraction (ES) chest radiography on the detection
of pulmonary nodules and masses in daily routine. Seventy-seven patients and 25 healthy subjects were examined with a single
exposure digital radiography system. Five blinded readers evaluated first the non-subtracted PA and lateral chest radiographs
alone and then together with the subtracted PA soft tissue images. The size, location and number of lung nodules or masses
were registered with the confidence level. CT was used as standard of reference. For the 200 total lesions, a sensitivity
of 33.5–52.5% was found at non-subtracted and a sensitivity of 43.5–58.5% at energy-subtracted radiography, corresponding
to a significant improvement in four of five readers (p < 0.05). However, in three of five readers the rate of false positives
was higher with ES. With ES, sensitivity, but not the area under the alternative free-response receiver operating characteristics
(AFROC) curve, showed a good correlation with reader experience (R = 0.90, p = 0.026). In four of five readers, the diagnostic
confidence improved with ES (p = 0.0036). We conclude that single-exposure digital ES chest radiography improves detection
of most pulmonary nodules and masses, but identification of nodules <1 cm and false-positive findings remain a problem. 相似文献
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D.W.De Boo F.van Hoorn J.van Schuppen L.Schijf M.J.Scheerder N.J.Freling 吴越菲 《国际医学放射学杂志》2012,(5):503
摘要目的评估短期反馈能否帮助观察者提高在数字化胸片中运用计算机辅助系统(CAD)检测肺结节的能力。方法140例胸部平片(56例CT证实存在孤立性肺结节,84例为阴性对照)分为4组,每组各35例;每组均有6名观察者按不同顺序阅片。在有和没有CAD(IQQA-Chest,EDDA Technology)辅助情况下分别对病变的存在、部位、诊断的可靠性进行计分。观察者在每组阅片后获得独立的反馈。 相似文献
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D L Ergun C A Mistretta D E Brown R T Bystrianyk W K Sze F Kelcz D P Naidich 《Radiology》1990,174(1):243-249
Recent reports have emphasized the potential for dual-energy computed radiographic applications. An improved method for single-exposure material-selective imaging with a photostimulable phosphor computed radiography system was investigated. The essential elements of the technique are (a) prefiltration with gadolinium, which divides the incident broad-beam x-ray spectrum into low-energy and high-energy peaks; (b) a cassette consisting of four photostimulable phosphor plates that record images of increasing mean energies, with a computed energy separation of 23 keV from the front to the rear plate; (c) spatially dependent scatter and beam-hardening corrections; and (d) a noise-reduction algorithm based on noise correlations between bone-selective and soft-tissue-selective dual-energy images. These elements result in improved material cancellation and signal-to-noise ratio throughout the image. 相似文献
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This paper presents the results of a nodule detection study, using a Humanoid chest phantom, which was designed to evaluate the performance of two types of dual-energy and conventional (single-energy) chest radiography. The film-screen apparatis were used as image detectors for all imaging modalities. The area under the ROC curve and the cumulative true-positive fraction both were used as performance indexes in the evaluation. Because of the small number of false-positive responses in the observer studies, the cumulative true-positive fraction was eventually regarded as a more conclusive index of accuracy than the area under the ROC curve to make a reasonable conclusion. Both dual-energy techniques, dual- and single-exposure, were found to be superior to conventional chest radiography, P less than 0.0005 and P less than 0.006 for dual- and single-exposure techniques, respectively. The difference between the two dual-energy techniques was statistically insignificant, P less than 0.47. We concluded that the dual-energy, single-exposure technique is worthy of further clinical study based on these encouraging results and because of the ease with which the technique can be implemented. 相似文献
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Seitaro Oda Kazuo Awai Yoshinori Funama Daisuke Utsunomiya Yumi Yanaga Koichi Kawanaka Yasuyuki Yamashita 《Japanese journal of radiology》2010,28(3):214-219
Purpose
The aim of this study was to investigate the detectability of simulated pulmonary nodules with different X-ray attenuation by flat-panel detector (FPD) chest radiography using a dual-exposure dual-energy subtraction (DES) technique. 相似文献17.
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HASTE MRI versus chest radiography in the detection of pulmonary nodules: comparison with MDCT. 总被引:7,自引:0,他引:7
Florian M Vogt Christoph U Herborn Peter Hunold Thomas C Lauenstein Tobias Schr?der J?rg F Debatin J?rg Barkhausen 《AJR. American journal of roentgenology》2004,183(1):71-78
OBJECTIVE: The purpose of our study was to compare the diagnostic accuracy of an ultrafast ECG-triggered black blood-prepared HASTE sequence with chest radiography for the detection of pulmonary nodules. SUBJECTS AND METHODS. Sixty-four patients with various primary malignancies who had undergone radiography and MDCT of the chest also underwent ECG-triggered black blood-prepared HASTE MRI of the lung. MR images and radiographs were interpreted separately. The number, location, and size of detected lesions were recorded, and each hemithorax was classified as affected or not affected on the basis of a grade reflecting the conspicuity of nodular involvement. Sensitivity, specificity, and positive and negative predictive values for the detection of pulmonary nodules with diameters of 5 mm or larger were determined, using MDCT findings as the standard of reference. Lesions with diameters smaller than 5 mm were not evaluated. Additional lesion-by-lesion comparisons between MDCT and MRI findings were performed. RESULTS: MDCT confirmed pulmonary lesions in 32 patients, whereas HASTE MRI revealed lesions in 30 patients and chest radiography, in 19 patients. MDCT revealed 226 nodules in 32 patients, whereas MRI HASTE revealed 227 lesions in 30 patients. Conspicuity scale-based sensitivity and specificity for chest radiography were 55.8% and 92.4%, respectively, whereas HASTE MRI had a sensitivity of 93.0% and a specificity of 96.2%. Positive and negative predictive values for chest radiography were 80% and 79.3%, respectively, and for HASTE MRI, 93.0% and 96.2%, respectively. The sensitivity of HASTE MRI increased with lesion size, ranging from 94.9% for nodules between 5 and 10 mm in diameter to 100% for lesions exceeding 3 cm in diameter. CONCLUSION: ECG-triggered black blood-prepared HASTE MRI is reliable for detecting pulmonary nodules exceeding 5 mm and has proven significantly more accurate than conventional chest radiography. The technique appears useful as an adjunct to MRI of the heart, great vessels, or chest, potentially increasing the diagnostic yield of MRI examinations. 相似文献
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Bone images from dual-energy subtraction chest radiography in the detection of rib fractures 总被引:1,自引:0,他引:1