Enhanced latitude for digital projection radiography

Metter, Richard L. Van; Foos, David H.

doi:10.1117/12.349459

Cited by 16 publications

(18 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Systematic studies confirmed, that conventional x-ray films in many cases can not encompass the whole range of exposures [1,2]. This may be covered with wide-latitude films, but only at the cost of a considerable loss in edge contrast [3]. Asymmetric screen-film systems using a dual image receptor screen-film combination were introduced to improve mediastinal and retro-cardiac detail.…”

Section: Introductionmentioning

confidence: 96%

“…New perspectives have emerged, since storage phosphor image receptors and digital radiographic detectors have started to replace conventional film-screen radiography [3,8]. Both modalities record a much wider range of exposures than a conventional x-ray film.…”

Section: Introductionmentioning

confidence: 99%

“…Principally these data have been already truncated by pre-processing, and the effectiveness of such procedures is potentially limited. However, both methods, DRC and EVP have been already commercially introduced and studies with storage phosphor systems have demonstrated their potential for displaying digital chest images with a wide dynamic range [3,9].…”

Section: Introductionmentioning

confidence: 99%

“…A product called EVP (enhanced visualization processing, Eastman Kodak Company, Rochester, NY, USA), divides the raw image information into high and low frequency image components. The high frequencies encode small detail contrast and the low frequencies encode basic image contrast [3]. The contrast of the low frequency image is reduced, thereby increasing the latitude (with the latitude being defined as the difference between the lowest and the highest exposure value covered with the grey scale of the image.…”

Section: Introductionmentioning

confidence: 99%

“…Different techniques to widen the dynamic range of digital images have been reported [3,9]. A product called EVP (enhanced visualization processing, Eastman Kodak Company, Rochester, NY, USA), divides the raw image information into high and low frequency image components.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Pulmonary nodule detection with digital projection radiography: an ex-vivo study on increased latitude post-processing

et al. 2006

View full text Add to dashboard Cite

To evaluate increased image latitude post-processing of digital projection radiograms for the detection of pulmonary nodules. 20 porcine lungs were inflated inside a chest phantom, prepared with 280 solid nodules of 4-8 mm in diameter and examined with direct radiography (3.0x2.5 k detector, 125 kVp, 4 mAs). Nodule position and size were documented by CT controls and dissection. Four intact lungs served as negative controls. Image post-processing included standard tone scales and increased latitude with detail contrast enhancement (log-factors 1.0, 1.5 and 2.0). 1280 sub-images (512x512 pixel) were centred on nodules or controls, behind the diaphragm and over free parenchyma, randomized and presented to six readers. Confidence in the decision was recorded with a scale of 0-100%. Sensitivity and specificity for nodules behind the diaphragm were 0.87/0.97 at standard tone scale and 0.92/0.92 with increased latitude (log factor 2.0). The fraction of "not diagnostic" readings was reduced (from 208/1920 to 52/1920). As an indicator of increased detection confidence, the median of the ratings behind the diaphragm approached 100 and 0, respectively, and the inter-quartile width decreased (controls: p<0.001, nodules: p=0.239) at higher image latitude. Above the diaphragm, accuracy and detection confidence remained unchanged. Here, the sensitivity for nodules was 0.94 with a specificity from 0.96 to 0.97 (all p>0.05). Increased latitude post-processing has minimal effects on the overall accuracy, but improves the detection confidence for sub-centimeter nodules in the posterior recesses of the lung.

show abstract

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Pulmonary nodule detection with digital projection radiography: an ex-vivo study on increased latitude post-processing

et al. 2006

View full text Add to dashboard Cite

show abstract

Interactive Image Enhancement of CR and DR Images

et al. 2004

View full text Add to dashboard Cite

There is continual pressure on the radiology department to increase its productivity. Two important links to productivity in the computed/digital radiography (CR/DR) workflow chain are the postprocessing step by technologists and the primary diagnosis step by radiologists, who may apply additional image enhancements to aid them in diagnosis. With the large matrix size of CR and DR images and the computational complexity of these algorithms, it has been challenging to provide interactive image enhancement, particularly on full-resolution images. We have used a new programmable processor as the main computing engine of enhancement algorithms for CR or DR images. We have mapped these algorithms to the processor, maximally utilizing its architecture. On a 12-bit 2688 x 2688 image, we have achieved the execution time of 465A ms for adaptive unsharp masking, window/level, image rotate, and lookup table operations using a single processor, which represents at least an order of magnitude improvement compared to the response time of current systems. This kind of performance facilitates rapid computation with preset parameter values and/or enables truly interactive QA processing on radiographs by technologists. The fast response time of these algorithms would be especially useful in a real-time radiology setting, where the radiologist's waiting time in performing image enhancements before making diagnosis can be greatly reduced. We believe that the use of these processors for fast CR/DR image computing coupled with the seamless flow of images and patient data will enable the radiology department to achieve higher productivity.

show abstract

Development of a High-performance Dual-energy Chest Imaging System

et al. 2009

View full text Add to dashboard Cite

Rationale and Objectives-To assess the performance of a newly developed dual-energy (DE) chest radiography system in comparison to digital radiography (DR) in the detection and characterization of lung nodules.Materials and Methods-An experimental prototype has been developed for high-performance DE chest imaging with total dose equivalent to a single posterior-anterior DR image. Low-and highkVp projections were used to decompose DE soft-tissue and bone images. A cohort of 55 patients (31 male, 24 female, mean age 65.6 years) was drawn from an ongoing trial involving patients referred for percutaneous CT guided biopsy of suspicious lung nodules. DE and DR images were acquired of each patient prior to biopsy. Image quality was assessed by means of human observer tests involving 5 radiologists independently rating the detection and characterization of lung nodules on a 9-point scale. Results were analyzed in terms of the fraction of cases at or above a given rating, and statistical significance was evaluated from a Wilcoxon signed rank test. Performance was analyzed for all cases pooled as well as by stratification of nodule size, density, lung region, and chest thickness.Results-The studies demonstrate a significant performance advantage for DE imaging compared to DR (p<0.001) in the detection and characterization of lung nodules. DE imaging improved the detection of both small and large nodules and exhibited the most significant improvement in regions of the upper lobes, where overlying anatomical noise (ribs and clavicles) are believed to reduce nodule conspicuity in DR.Conclusions-DE imaging outperformed DR overall, particularly in the detection of small, solid nodules. DE imaging also performed better in regions dominated by anatomical noise such as the lung apices. The potential for improved nodule detection and characterization at radiation doses equivalent to DR is encouraging and could augment broader utilization of DE imaging. F studies will

show abstract

Enhanced latitude for digital projection radiography

Cited by 16 publications

References 6 publications

Pulmonary nodule detection with digital projection radiography: an ex-vivo study on increased latitude post-processing

Pulmonary nodule detection with digital projection radiography: an ex-vivo study on increased latitude post-processing

Interactive Image Enhancement of CR and DR Images

Development of a High-performance Dual-energy Chest Imaging System

Contact Info

Product

Resources

About