WorldWideScience

Sample records for computer-aided detection cad

  1. Lung nodule detection on chest CT: evaluation of a computer-aided detection (CAD) system

    International Nuclear Information System (INIS)

    Lee, In Jae; Gamsu, Gordon; Czum, Julianna; Johnson, Rebecca; Chakrapani, Sanjay; Wu, Ning

    2005-01-01

    To evaluate the capacity of a computer-aided detection (CAD) system to detect lung nodules in clinical chest CT. A total of 210 consecutive clinical chest CT scans and their reports were reviewed by two chest radiologists and 70 were selected (33 without nodules and 37 with 1-6 nodules, 4-15.4 mm in diameter). The CAD system (ImageChecker CT LN-1000) developed by R2 Technology, Inc. (Sunnyvale, CA) was used. Its algorithm was designed to detect nodules with a diameter of 4-20 mm. The two chest radiologists working with the CAD system detected a total of 78 nodules. These 78 nodules form the database for this study. Four independent observers interpreted the studies with and without the CAD system. The detection rates of the four independent observers without CAD were 81% (63/78), 85% (66/78), 83% (65/78), and 83% (65/78), respectively. With CAD their rates were 87% (68/78), 85% (66/78), 86% (67/78), and 85% (66/78), respectively. The differences between these two sets of detection rates did not reach statistical significance. In addition, CAD detected eight nodules that were not mentioned in the original clinical radiology reports. The CAD system produced 1.56 false-positive nodules per CT study. The four test observers had 0, 0.1, 0.17, and 0.26 false-positive results per study without CAD and 0.07, 0.2, 0.23, and 0.39 with CAD, respectively. The CAD system can assist radiologists in detecting pulmonary nodules in chest CT, but with a potential increase in their false positive rates. Technological improvements to the system could increase the sensitivity and specificity for the detection of pulmonary nodules and reduce these false-positive results

  2. Computer-aided pulmonary nodule detection. Performance of two CAD systems at different CT dose levels

    International Nuclear Information System (INIS)

    Hein, Patrick Alexander; Rogalla, P.; Klessen, C.; Lembcke, A.; Romano, V.C.

    2009-01-01

    Purpose: To evaluate the impact of dose reduction on the performance of computer-aided lung nodule detection systems (CAD) of two manufacturers by comparing respective CAD results on ultra-low-dose computed tomography (ULD-CT) and standard dose CT (SD-CT). Materials and Methods: Multi-slice computed tomography (MSCT) data sets of 26 patients (13 male and 13 female, patients 31 - 74 years old) were retrospectively selected for CAD analysis. Indication for CT examination was staging of a known primary malignancy or suspected pulmonary malignancy. CT images were consecutively acquired at 5 mAs (ULD-CT) and 75 mAs (SD-CT) with 120kV tube voltage (1 mm slice thickness). The standard of reference was determined by three experienced readers in consensus. CAD reading algorithms (pre-commercial CAD system, Philips, Netherlands: CAD-1; LungCARE, Siemens, Germany: CAD-2) were applied to the CT data sets. Results: Consensus reading identified 253 nodules on SD-CT and ULD-CT. Nodules ranged in diameter between 2 and 41 mm (mean diameter 4.8 mm). Detection rates were recorded with 72% and 62% (CAD-1 vs. CAD-2) for SD-CT and with 73% and 56% for ULD-CT. Median also positive rates per patient were calculated with 6 and 5 (CAD-1 vs. CAD-2) for SD-CT and with 8 and 3 for ULD-CT. After separate statistical analysis of nodules with diameters of 5 mm and greater, the detection rates increased to 83% and 61% for SD-CT and to 89% and 67% for ULD-CT (CAD-1 vs. CAD-2). For both CAD systems there were no significant differences between the detection rates for standard and ultra-low-dose data sets (p>0.05). Conclusion: Dose reduction of the underlying CT scan did not significantly influence nodule detection performance of the tested CAD systems. (orig.)

  3. Progress of computer-aided detection/diagnosis (CAD in dentistryCAD in dentistry

    Directory of Open Access Journals (Sweden)

    Akitoshi Katsumata

    2014-08-01

    CAD is also useful in the detection and evaluation of dental and maxillofacial lesions. Identifying alveolar bone resorption due to periodontitis and radiolucent jaw lesions (such as radicular and dentigerous cysts are important goals for CAD. CAD can be applied not only to panoramic radiography but also to dental cone-beam computed tomography (CBCT images. Linking of CAD and teleradiology will be an important issue.

  4. Computer-aided detection (CAD) in mammography: Does it help the junior or the senior radiologist?

    International Nuclear Information System (INIS)

    Balleyguier, Corinne; Kinkel, Karen; Fermanian, Jacques; Malan, Sebastien; Djen, Germaine; Taourel, Patrice; Helenon, Olivier

    2005-01-01

    Objectives: To evaluate the impact of a computer-aided detection (CAD) system on the ability of a junior and senior radiologist to detect breast cancers on mammograms, and to determine the potential of CAD as a teaching tool in mammography. Methods: Hundred biopsy-proven cancers and 100 normal mammograms were randomly analyzed by a CAD system. The sensitivity (Se) and specificity (Sp) of the CAD system were calculated. In the second phase, to simulate daily practice, 110 mammograms (97 normal or with benign lesions, and 13 cancers) were examined independently by a junior and a senior radiologist, with and without CAD. Interpretations were standardized according to BI-RADS classification. Sensitivity, Specificity, positive and negative predictive values (PPV, NPV) were calculated for each session. Results: For the senior radiologist, Se slightly improved from 76.9 to 84.6% after CAD analysis (NS) (one case of clustered microcalcifications case overlooked by the senior radiologist was detected by CAD). Sp, PPV and PNV did not change significantly. For the junior radiologist, Se improved from 61.9 to 84.6% (significant change). Three cancers overlooked by the junior radiologist were detected by CAD. Sp was unchanged. Conclusion: CAD mammography proved more useful for the junior than for the senior radiologist, improving sensitivity. The CAD system may represent a useful educational tool for mammography

  5. Clinical evaluation of a computer-aided diagnosis (CAD) prototype for the detection of pulmonary embolism.

    Science.gov (United States)

    Buhmann, Sonja; Herzog, Peter; Liang, Jin; Wolf, Mathias; Salganicoff, Marcos; Kirchhoff, Chlodwig; Reiser, Maximilian; Becker, Christoph H

    2007-06-01

    To evaluate the performance of a prototype computer-aided diagnosis (CAD) tool using artificial intelligence techniques for the detection of pulmonary embolism (PE) and the possible benefit for general radiologists. Forty multidetector row computed tomography datasets (16/64- channel scanner) using 100 kVp, 100 mAs effective/slice, and 1-mm axial reformats in a low-frequency reconstruction kernel were evaluated. A total of 80 mL iodinated contrast material was injected at a flow rate of 5 mL/seconds. Primarily, six general radiologists marked any PE using a commercially available lung evaluation software with simultaneous, automatic processing by CAD in the background. An expert panel consisting of two chest radiologists analyzed all PE marks from the readers and CAD, also searching for additional finding primarily missed by both, forming the ground truth. The ground truth consisted of 212 emboli. Of these, 65 (31%) were centrally and 147 (69%) were peripherally located. The readers detected 157/212 emboli (74%) leading to a sensitivity of 97% (63/65) for central and 70% (103/147) for peripheral emboli with 9 false-positive findings. CAD detected 168/212 emboli (79%), reaching a sensitivity of 74% for central (48/65) and 82%(120/147) for peripheral emboli. A total of 154 CAD candidates were considered as false positives, yielding an average of 3.85 false positives/case. The CAD software showed a sensitivity comparable to that of the general radiologists, but with more false positives. CAD detection of findings incremental to the radiologists suggests benefit when used as a second reader. Future versions of CAD have the potential to further increase clinical benefit by improving sensitivity and reducing false marks.

  6. The efficacy of using computer-aided detection (CAD) for detection of breast cancer in mammography screening

    DEFF Research Database (Denmark)

    Henriksen, Emilie L; Carlsen, Jonathan F; Vejborg, Ilse Mm

    2018-01-01

    Background Early detection of breast cancer (BC) is crucial in lowering the mortality. Purpose To present an overview of studies concerning computer-aided detection (CAD) in screening mammography for early detection of BC and compare diagnostic accuracy and recall rates (RR) of single reading (SR......) with SR + CAD and double reading (DR) with SR + CAD. Material and Methods PRISMA guidelines were used as a review protocol. Articles on clinical trials concerning CAD for detection of BC in a screening population were included. The literature search resulted in 1522 records. A total of 1491 records were...... excluded by abstract and 18 were excluded by full text reading. A total of 13 articles were included. Results All but two studies from the SR vs. SR + CAD group showed an increased sensitivity and/or cancer detection rate (CDR) when adding CAD. The DR vs. SR + CAD group showed no significant differences...

  7. Computer-aided detection (CAD) of lung nodules and small tumours on chest radiographs

    International Nuclear Information System (INIS)

    De Boo, D.W.; Prokop, M.; Uffmann, M.; Ginneken, B. van; Schaefer-Prokop, C.M.

    2009-01-01

    Detection of focal pulmonary lesions is limited by quantum and anatomic noise and highly influenced by variable perception capacity of the reader. Multiple studies have proven that lesions - missed at time of primary interpretation - were visible on the chest radiographs in retrospect. Computer-aided diagnosis (CAD) schemes do not alter the anatomic noise but aim at decreasing the intrinsic limitations and variations of human perception by alerting the reader to suspicious areas in a chest radiograph when used as a 'second reader'. Multiple studies have shown that the detection performance can be improved using CAD especially for less experienced readers at a variable amount of decreased specificity. There seem to be a substantial learning process for both, experienced and inexperienced readers, to be able to optimally differentiate between false positive and true positive lesions and to build up sufficient trust in the capabilities of these systems to be able to use them at their full advantage. Studies so far focussed on stand-alone performance of the CAD schemes to reveal the magnitude of potential impact or on retrospective evaluation of CAD as a second reader for selected study groups. Further research is needed to assess the performance of these systems in clinical routine and to determine the trade-off between performance increase in terms of increased sensitivity and decreased inter-reader variability and loss of specificity and secondary indicated follow-up examinations for further diagnostic workup.

  8. Reproducibility of prompts in computer-aided detection (CAD) of breast cancer

    International Nuclear Information System (INIS)

    Taylor, C.G.; Champness, J.; Reddy, M.; Taylor, P.; Potts, H.W.W.; Given-Wilson, R.

    2003-01-01

    AIM: We evaluated the reproducibility of prompts using the R2 ImageChecker M2000 computer-aided detection (CAD) system. MATERIALS AND METHODS: Forty selected two-view mammograms of women with breast cancer were digitized and analysed using the ImageChecker on 10 separate occasions. The mammograms were chosen to provide both straightforward and subtle signs of malignancy. Data analysed included mammographic abnormality, pathology, and whether the cancer was prompted or given an emphasized prompt. RESULTS: Correct prompts were generated in 86 out of 100 occasions for screen-detected cancers. Reproducibility was less in the other categories of more subtle cancers: 21% for cancers previously missed by CAD, a group that contained more grade 1 and small (<10 mm) tumours. Prompts for calcifications were more reproducible than those for masses (76% versus 53%) and these cancers were more likely to have an emphasized prompt. CONCLUSIONS: Probably the most important cause of variability of prompts is shifts in film position between sequential digitizations. Consequently subtle lesions that are only just above the threshold for display may not be prompted on repeat scanning. However, users of CAD should be aware that even emphasized prompts are not consistently reproducible

  9. The efficacy of using computer-aided detection (CAD) for detection of breast cancer in mammography screening: a systematic review.

    Science.gov (United States)

    Henriksen, Emilie L; Carlsen, Jonathan F; Vejborg, Ilse Mm; Nielsen, Michael B; Lauridsen, Carsten A

    2018-01-01

    Background Early detection of breast cancer (BC) is crucial in lowering the mortality. Purpose To present an overview of studies concerning computer-aided detection (CAD) in screening mammography for early detection of BC and compare diagnostic accuracy and recall rates (RR) of single reading (SR) with SR + CAD and double reading (DR) with SR + CAD. Material and Methods PRISMA guidelines were used as a review protocol. Articles on clinical trials concerning CAD for detection of BC in a screening population were included. The literature search resulted in 1522 records. A total of 1491 records were excluded by abstract and 18 were excluded by full text reading. A total of 13 articles were included. Results All but two studies from the SR vs. SR + CAD group showed an increased sensitivity and/or cancer detection rate (CDR) when adding CAD. The DR vs. SR + CAD group showed no significant differences in sensitivity and CDR. Adding CAD to SR increased the RR and decreased the specificity in all but one study. For the DR vs. SR + CAD group only one study reported a significant difference in RR. Conclusion All but two studies showed an increase in RR, sensitivity and CDR when adding CAD to SR. Compared to DR no statistically significant differences in sensitivity or CDR were reported. Additional studies based on organized population-based screening programs, with longer follow-up time, high-volume readers, and digital mammography are needed to evaluate the efficacy of CAD.

  10. When and why might a Computer Aided Detection (CAD) system interfere with visual search? An eye-tracking study

    Science.gov (United States)

    Drew, Trafton; Cunningham, Corbin; Wolfe, Jeremy

    2012-01-01

    Rational and Objectives Computer Aided Detection (CAD) systems are intended to improve performance. This study investigates how CAD might actually interfere with a visual search task. This is a laboratory study with implications for clinical use of CAD. Methods 47 naïve observers in two studies were asked to search for a target, embedded in 1/f2.4 noise while we monitored their eye-movements. For some observers, a CAD system marked 75% of targets and 10% of distractors while other observers completed the study without CAD. In Experiment 1, the CAD system’s primary function was to tell observers where the target might be. In Experiment 2, CAD provided information about target identity. Results In Experiment 1, there was a significant enhancement of observer sensitivity in the presence of CAD (t(22)=4.74, pCAD system were missed more frequently than equivalent targets in No CAD blocks of the experiment (t(22)=7.02, pCAD, but also no significant cost on sensitivity to unmarked targets (t(22)=0.6, p=n.s.). Finally, in both experiments, CAD produced reliable changes in eye-movements: CAD observers examined a lower total percentage of the search area than the No CAD observers (Ex 1: t(48)=3.05, pCAD signals do not combine with observers’ unaided performance in a straight-forward manner. CAD can engender a sense of certainty that can lead to incomplete search and elevated chances of missing unmarked stimuli. PMID:22958720

  11. Comparison of standard reading and computer aided detection (CAD) on a national proficiency test of screening mammography

    International Nuclear Information System (INIS)

    Ciatto, Stefano; Del Turco, Marco Rosselli; Risso, Gabriella; Catarzi, Sandra; Bonardi, Rita; Viterbo, Valeria; Gnutti, Pierangela; Guglielmoni, Barbara; Pinelli, Lelio; Pandiscia, Anna; Navarra, Francesco; Lauria, Adele; Palmiero, Rosa; Indovina, Pietro Luigi

    2003-01-01

    Objective: To evaluate the role of computer aided detection (CAD) in improving the interpretation of screening mammograms Material and methods: Ten radiologists underwent a proficiency test of screening mammography first by conventional reading and then with the help of CAD. Radiologists were blinded to test results for the whole study duration. Results of conventional and CAD reading were compared in terms of sensitivity and recall rate. Double reading was simulated combining conventional readings of four expert radiologists and compared with CAD reading. Results: Considering all ten readings, cancer was identified in 146 or 153 of 170 cases (85.8 vs. 90.0%; χ 2 =0.99, df=1, P=0.31) and recalls were 106 or 152 of 1330 cases (7.9 vs. 11.4%; χ 2 =8.69, df=1, P=0.003) at conventional or CAD reading, respectively. CAD reading was essentially the same (sensitivity 97.0 vs. 96.0%; χ 2 =7.1, df=1, P=0.93; recall rate 10.7 vs. 10.6%; χ 2 =1.5, df=1, P=0.96) as compared with simulated conventional double reading. Conclusion: CAD reading seems to improve the sensitivity of conventional reading while reducing specificity, both effects being of limited size. CAD reading had almost the same performance of simulated conventional double reading, suggesting a possible use of CAD which needs to be confirmed by further studies inclusive of cost-effective analysis

  12. Computer-aided detection (CAD) of lung nodules in CT scans: radiologist performance and reading time with incremental CAD assistance

    International Nuclear Information System (INIS)

    Roos, Justus E.; Paik, David; Olsen, David; Liu, Emily G.; Leung, Ann N.; Mindelzun, Robert; Choudhury, Kingshuk R.; Napel, Sandy; Rubin, Geoffrey D.; Chow, Lawrence C.; Naidich, David P.

    2010-01-01

    The diagnostic performance of radiologists using incremental CAD assistance for lung nodule detection on CT and their temporal variation in performance during CAD evaluation was assessed. CAD was applied to 20 chest multidetector-row computed tomography (MDCT) scans containing 190 non-calcified ≥3-mm nodules. After free search, three radiologists independently evaluated a maximum of up to 50 CAD detections/patient. Multiple free-response ROC curves were generated for free search and successive CAD evaluation, by incrementally adding CAD detections one at a time to the radiologists' performance. The sensitivity for free search was 53% (range, 44%-59%) at 1.15 false positives (FP)/patient and increased with CAD to 69% (range, 59-82%) at 1.45 FP/patient. CAD evaluation initially resulted in a sharp rise in sensitivity of 14% with a minimal increase in FP over a time period of 100 s, followed by flattening of the sensitivity increase to only 2%. This transition resulted from a greater prevalence of true positive (TP) versus FP detections at early CAD evaluation and not by a temporal change in readers' performance. The time spent for TP (9.5 s ± 4.5 s) and false negative (FN) (8.4 s ± 6.7 s) detections was similar; FP decisions took two- to three-times longer (14.4 s ± 8.7 s) than true negative (TN) decisions (4.7 s ± 1.3 s). When CAD output is ordered by CAD score, an initial period of rapid performance improvement slows significantly over time because of non-uniformity in the distribution of TP CAD output and not to a changing reader performance over time. (orig.)

  13. A computer-aided detection (CAD) system with a 3D algorithm for small acute intracranial hemorrhage

    Science.gov (United States)

    Wang, Ximing; Fernandez, James; Deshpande, Ruchi; Lee, Joon K.; Chan, Tao; Liu, Brent

    2012-02-01

    Acute Intracranial hemorrhage (AIH) requires urgent diagnosis in the emergency setting to mitigate eventual sequelae. However, experienced radiologists may not always be available to make a timely diagnosis. This is especially true for small AIH, defined as lesion smaller than 10 mm in size. A computer-aided detection (CAD) system for the detection of small AIH would facilitate timely diagnosis. A previously developed 2D algorithm shows high false positive rates in the evaluation based on LAC/USC cases, due to the limitation of setting up correct coordinate system for the knowledge-based classification system. To achieve a higher sensitivity and specificity, a new 3D algorithm is developed. The algorithm utilizes a top-hat transformation and dynamic threshold map to detect small AIH lesions. Several key structures of brain are detected and are used to set up a 3D anatomical coordinate system. A rule-based classification of the lesion detected is applied based on the anatomical coordinate system. For convenient evaluation in clinical environment, the CAD module is integrated with a stand-alone system. The CAD is evaluated by small AIH cases and matched normal collected in LAC/USC. The result of 3D CAD and the previous 2D CAD has been compared.

  14. Is computer aided detection (CAD) cost effective in screening mammography? A model based on the CADET II study

    Science.gov (United States)

    2011-01-01

    Background Single reading with computer aided detection (CAD) is an alternative to double reading for detecting cancer in screening mammograms. The aim of this study is to investigate whether the use of a single reader with CAD is more cost-effective than double reading. Methods Based on data from the CADET II study, the cost-effectiveness of single reading with CAD versus double reading was measured in terms of cost per cancer detected. Cost (Pound (£), year 2007/08) of single reading with CAD versus double reading was estimated assuming a health and social service perspective and a 7 year time horizon. As the equipment cost varies according to the unit size a separate analysis was conducted for high, average and low volume screening units. One-way sensitivity analyses were performed by varying the reading time, equipment and assessment cost, recall rate and reader qualification. Results CAD is cost increasing for all sizes of screening unit. The introduction of CAD is cost-increasing compared to double reading because the cost of CAD equipment, staff training and the higher assessment cost associated with CAD are greater than the saving in reading costs. The introduction of single reading with CAD, in place of double reading, would produce an additional cost of £227 and £253 per 1,000 women screened in high and average volume units respectively. In low volume screening units, the high cost of purchasing the equipment will results in an additional cost of £590 per 1,000 women screened. One-way sensitivity analysis showed that the factors having the greatest effect on the cost-effectiveness of CAD with single reading compared with double reading were the reading time and the reader's professional qualification (radiologist versus advanced practitioner). Conclusions Without improvements in CAD effectiveness (e.g. a decrease in the recall rate) CAD is unlikely to be a cost effective alternative to double reading for mammography screening in UK. This study

  15. Integration of computer-aided diagnosis/detection (CAD) results in a PACS environment using CAD-PACS toolkit and DICOM SR

    International Nuclear Information System (INIS)

    Le, Anh H.T.; Liu, Brent; Huang, H.K.

    2009-01-01

    Picture Archiving and Communication System (PACS) is a mature technology in health care delivery for daily clinical imaging service and data management. Computer-aided detection and diagnosis (CAD) utilizes computer methods to obtain quantitative measurements from medical images and clinical information to assist clinicians to assess a patient's clinical state more objectively. CAD needs image input and related information from PACS to improve its accuracy; and PACS benefits from CAD results online and available at the PACS workstation as a second reader to assist physicians in the decision making process. Currently, these two technologies remain as two separate independent systems with only minimal system integration. This paper describes a universal method to integrate CAD results with PACS in its daily clinical environment. The method is based on Health Level 7 (HL7) and Digital imaging and communications in medicine (DICOM) standards, and Integrating the Healthcare Enterprise (IHE) workflow profiles. In addition, the integration method is Health Insurance Portability and Accountability Act (HIPAA) compliant. The paper presents (1) the clinical value and advantages of integrating CAD results in a PACS environment, (2) DICOM Structured Reporting formats and some important IHE workflow profiles utilized in the system integration, (3) the methodology using the CAD-PACS integration toolkit, and (4) clinical examples with step-by-step workflows of this integration. (orig.)

  16. Can breast MRI computer-aided detection (CAD) improve radiologist accuracy for lesions detected at MRI screening and recommended for biopsy in a high-risk population?

    International Nuclear Information System (INIS)

    Arazi-Kleinman, T.; Causer, P.A.; Jong, R.A.; Hill, K.; Warner, E.

    2009-01-01

    Aim: To evaluate the sensitivity and specificity of magnetic resonance imaging (MRI) computer-aided detection (CAD) for breast MRI screen-detected lesions recommended for biopsy in a high-risk population. Material and methods: Fifty-six consecutive Breast Imaging Reporting and Data System (BI-RADS) 3-5 lesions with histopathological correlation [nine invasive cancers, 13 ductal carcinoma in situ (DCIS) and 34 benign] were retrospectively evaluated using a breast MRI CAD prototype (CAD-Gaea). CAD evaluation was performed separately and in consensus by two radiologists specializing in breast imaging, blinded to the histopathology. Thresholds of 50, 80, and 100% and delayed enhancement were independently assessed with CAD. Lesions were rated as malignant or benign according to threshold and delayed enhancement only and in combination. Sensitivities, specificities, and negative predictive values (NPV) were determined for CAD assessments versus pathology. Initial MRI BI-RADS interpretation without CAD versus CAD assessments were compared using paired binary diagnostic tests. Results: Threshold levels for lesion enhancement were: 50% to include all malignant (and all benign) lesions; and 100% for all invasive cancer and high-grade DCIS. Combined use of threshold and enhancement patterns for CAD assessment was best (73% sensitivity, 56% specificity and 76% NPV for all cancer). Sensitivities and NPV were better for invasive cancer (100%/100%) than for all malignancies (54%/76%). Radiologists' MRI interpretation was more sensitive than CAD (p = 0.05), but less specific (p = 0.001) for cancer detection. Conclusion: The breast MRI CAD system used could not improve the radiologists' accuracy for distinguishing all malignant from benign lesions, due to the poor sensitivity for DCIS detection.

  17. Role of Computer Aided Diagnosis (CAD) in the detection of pulmonary nodules on 64 row multi detector computed tomography.

    Science.gov (United States)

    Prakashini, K; Babu, Satish; Rajgopal, K V; Kokila, K Raja

    2016-01-01

    To determine the overall performance of an existing CAD algorithm with thin-section computed tomography (CT) in the detection of pulmonary nodules and to evaluate detection sensitivity at a varying range of nodule density, size, and location. A cross-sectional prospective study was conducted on 20 patients with 322 suspected nodules who underwent diagnostic chest imaging using 64-row multi-detector CT. The examinations were evaluated on reconstructed images of 1.4 mm thickness and 0.7 mm interval. Detection of pulmonary nodules, initially by a radiologist of 2 years experience (RAD) and later by CAD lung nodule software was assessed. Then, CAD nodule candidates were accepted or rejected accordingly. Detected nodules were classified based on their size, density, and location. The performance of the RAD and CAD system was compared with the gold standard that is true nodules confirmed by consensus of senior RAD and CAD together. The overall sensitivity and false-positive (FP) rate of CAD software was calculated. Of the 322 suspected nodules, 221 were classified as true nodules on the consensus of senior RAD and CAD together. Of the true nodules, the RAD detected 206 (93.2%) and 202 (91.4%) by the CAD. CAD and RAD together picked up more number of nodules than either CAD or RAD alone. Overall sensitivity for nodule detection with the CAD program was 91.4%, and FP detection per patient was 5.5%. The CAD showed comparatively higher sensitivity for nodules of size 4-10 mm (93.4%) and nodules in hilar (100%) and central (96.5%) location when compared to RAD's performance. CAD performance was high in detecting pulmonary nodules including the small size and low-density nodules. CAD even with relatively high FP rate, assists and improves RAD's performance as a second reader, especially for nodules located in the central and hilar region and for small nodules by saving RADs time.

  18. Present state of computer-aided diagnosis (CAD) development

    International Nuclear Information System (INIS)

    Fujita, Hiroshi

    2007-01-01

    Topics of computer-aided detection (CAD) are reviewed. Commercially available, Food and Drug Administration (FDA)-approved CAD systems are for fields of breast cancer (mammography), chest (flat X-ray and CT imaging) and colon (polyp detection). In Japan, only mammography CAD is approved. Efficacy of CAD is controversial, for which reliable database is important, and its construction is under development in various medical fields. Digitalized image is now popularized, which conceivably leads to improve the cost-effectiveness of diagnosis with CAD. For incentive, approval for health insurance would be the case as seen in the increased CAD sale by R2 Technology Co., and MHLW actually assists facilities to introduce the reading-aid system of mammography by sharing a half of its cost. There are 2 big projects for CAD study supported by MECSST, which the author concerns. One is the development of diagnostic aid for the multi-dimensional medical images where the multi-organ, multi-disease CAD system is considered. The other involves the CAD in brain MRI, in breast US and in eyeground picture. It is not in so far future for patients and doctors to fully enjoy the benefit of CAD. (R.T.)

  19. Role of Computer Aided Diagnosis (CAD in the detection of pulmonary nodules on 64 row multi detector computed tomography

    Directory of Open Access Journals (Sweden)

    K Prakashini

    2016-01-01

    Full Text Available Aims and Objectives: To determine the overall performance of an existing CAD algorithm with thin-section computed tomography (CT in the detection of pulmonary nodules and to evaluate detection sensitivity at a varying range of nodule density, size, and location. Materials and Methods: A cross-sectional prospective study was conducted on 20 patients with 322 suspected nodules who underwent diagnostic chest imaging using 64-row multi-detector CT. The examinations were evaluated on reconstructed images of 1.4 mm thickness and 0.7 mm interval. Detection of pulmonary nodules, initially by a radiologist of 2 years experience (RAD and later by CAD lung nodule software was assessed. Then, CAD nodule candidates were accepted or rejected accordingly. Detected nodules were classified based on their size, density, and location. The performance of the RAD and CAD system was compared with the gold standard that is true nodules confirmed by consensus of senior RAD and CAD together. The overall sensitivity and false-positive (FP rate of CAD software was calculated. Observations and Results: Of the 322 suspected nodules, 221 were classified as true nodules on the consensus of senior RAD and CAD together. Of the true nodules, the RAD detected 206 (93.2% and 202 (91.4% by the CAD. CAD and RAD together picked up more number of nodules than either CAD or RAD alone. Overall sensitivity for nodule detection with the CAD program was 91.4%, and FP detection per patient was 5.5%. The CAD showed comparatively higher sensitivity for nodules of size 4-10 mm (93.4% and nodules in hilar (100% and central (96.5% location when compared to RAD′s performance. Conclusion: CAD performance was high in detecting pulmonary nodules including the small size and low-density nodules. CAD even with relatively high FP rate, assists and improves RAD′s performance as a second reader, especially for nodules located in the central and hilar region and for small nodules by saving RADs time.

  20. Improving digital breast tomosynthesis reading time: A pilot multi-reader, multi-case study using concurrent Computer-Aided Detection (CAD).

    Science.gov (United States)

    Balleyguier, Corinne; Arfi-Rouche, Julia; Levy, Laurent; Toubiana, Patrick R; Cohen-Scali, Franck; Toledano, Alicia Y; Boyer, Bruno

    2017-12-01

    Evaluate concurrent Computer-Aided Detection (CAD) with Digital Breast Tomosynthesis (DBT) to determine impact on radiologist performance and reading time. The CAD system detects and extracts suspicious masses, architectural distortions and asymmetries from DBT planes that are blended into corresponding synthetic images to form CAD-enhanced synthetic images. Review of CAD-enhanced images and navigation to corresponding planes to confirm or dismiss potential lesions allows radiologists to more quickly review DBT planes. A retrospective, crossover study with and without CAD was conducted with six radiologists who read an enriched sample of 80 DBT cases including 23 malignant lesions in 21 women. Area Under the Receiver Operating Characteristic (ROC) Curve (AUC) compared the readings with and without CAD to determine the effect of CAD on overall interpretation performance. Sensitivity, specificity, recall rate and reading time were also assessed. Multi-reader, multi-case (MRMC) methods accounting for correlation and requiring correct lesion localization were used to analyze all endpoints. AUCs were based on a 0-100% probability of malignancy (POM) score. Sensitivity and specificity were based on BI-RADS scores, where 3 or higher was positive. Average AUC across readers without CAD was 0.854 (range: 0.785-0.891, 95% confidence interval (CI): 0.769,0.939) and 0.850 (range: 0.746-0.905, 95% CI: 0.751,0.949) with CAD (95% CI for difference: -0.046,0.039), demonstrating non-inferiority of AUC. Average reduction in reading time with CAD was 23.5% (95% CI: 7.0-37.0% improvement), from an average 48.2 (95% CI: 39.1,59.6) seconds without CAD to 39.1 (95% CI: 26.2,54.5) seconds with CAD. Per-patient sensitivity was the same with and without CAD (0.865; 95% CI for difference: -0.070,0.070), and there was a small 0.022 improvement (95% CI for difference: -0.046,0.089) in per-lesion sensitivity from 0.790 without CAD to 0.812 with CAD. A slight reduction in specificity with a -0

  1. Does the accuracy of single reading with CAD (computer-aided detection) compare with that of double reading?: A review of the literature

    International Nuclear Information System (INIS)

    Bennett, R.L.; Blanks, R.G.; Moss, S.M.

    2006-01-01

    Aim: To examine current evidence to determine whether the accuracy of single reading with computed-aided detection (CAD) compares with that of double reading. Methods: We performed a literature review to identify studies where both protocols had been investigated and compared. We identified eight studies that compared single reading with CAD against double reading, of which six reported on comparisons of both sensitivity and specificity. Results: Of the six studies identified, three showed no differences in either sensitivity or specificity. One showed single reading with CAD had a higher sensitivity at the same specificity, another that single reading with CAD had a higher specificity at the same sensitivity. However, one study, in a real-life setting, showed that single reading with CAD had a higher sensitivity but a lower specificity. Conclusion: As the majority of the studies were not in a real-life setting, used test sets, lacked sufficient training in the use of CAD and simulated double reading (using a protocol of recall if one suggests), current evidence is therefore limited as to the accuracy, in terms of sensitivity and specificity, of single reading with CAD in comparison with the most common practice in the UK of double reading using a protocol of consensus or arbitration

  2. Retrospective analysis of a Computer-Aided Detection (CAD) system in full-field digital mammography in correlation to tumor histology

    International Nuclear Information System (INIS)

    Obenauer, S.; Sohns, C.; Grabbe, E.; Werner, C.

    2005-01-01

    Purpose: to evaluate the usefulness of a computer-aided detection (CAD) system in full-field digital mammography in correlation to tumor histology. Material and methods: a total of 476 patients (226 patients with histologically proven malignant tumors, 250 healthy women) took part in this study. The mammograms were studied retrospectively, using the CAD system Image Checker. For 226 patients digital mammograms in MLO-projection were available. For 186 of these patients the CC-projection was also available. CAD markers that correlated with histologically proven carcinomas were considered to be true-positive markers. All other CAD markers were considered to be false-positive. Histologically proven carcinomas without markers were false-negative results. The dependence of the CAD markers placement upon the different carcinoma histologies was studied using the Chi-square test. Results: no significant difference could be proven for the detectability of malignant breast lesions of different histologic types. For the detectability of ductal carcinoma in situ (DCIS), invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), lobular carcinoma in situ (LCIS), tubular carcinoma and ductulo-lobular carcinoma, the true positives were 71.1%, 75%, 70.7%, 70%, 60% and 80%, respectively, in the MLO projection and 83.9%, 75.9%, 81.8%, 77.8%, 87.5% and 33.3%, respectively, in the CC projection. There was an average of 0.5 false-positive markers per mammographic image. Conclusion: The histologic type of carcinoma seems to have no influence on detectability when using the CAD system. The high rate of false-positive markers shows, however, the limited specificity of the CAD system and that improvements are necessary. (orig.)

  3. Nodule detection by chest X-ray and evaluation of computer-aided detection (CAD) software using an originally developed phantom for instructional purposes

    International Nuclear Information System (INIS)

    Nitta, Norihisa; Takahashi, Masashi; Takazakura, Ryutaro

    2006-01-01

    Chest X-ray and computed tomography (CT) are indispensable modalities for lung cancer examinations. CT technologies have dramatically improved and small nodules and obscure shadows have been detected more frequently. The new generation of radiologists feels that chest X-rays are not as useful as chest CT. Experiments using a newly-developed chest phantom were conducted to reconfirm blind spots in chest X-rays. Recent technological advances and high-definition capability have made chest X-rays more useful than ever. Even though development of multi-detector CT (MDCT) has facilitated detection of nodules, it has conversely incurred a problem of increasing data for analysis, taking tremendous time and effort. Here, employing a chest phantom and clinical samples, we evaluated the utility of two kinds of computer-aided detection (CAD) software (Image Checker CT and LungCARE NEV) as well as GGO CAD software that we have developed. More development of chest CT diagnostic software is urgently needed. (author)

  4. Computer-aided detection (CAD) and assessment of malignant lesions in the liver and lung using a novel PET/CT software tool. Initial results

    International Nuclear Information System (INIS)

    Hahn, Steffen; Heusner, T.; Forsting, M.; Antoch, G.; Zhou, X.; Zhan, Y.; Peng, Z.; Hamami, M.; Bockisch, A.

    2010-01-01

    Purpose: To determine the feasibility of a PET/CT software tool (PET computer-aided detection: PET-CAD) for automated detection and assessment of pulmonary and hepatic lesions. Materials and Methods: 20 consecutive patients with colorectal liver metastases and 20 consecutive patients suffering from non-small cell lung cancer (NSCLC) were examined with FDG-PET/CT. In a first step the maximum standardized uptake values (SUV max ) of non-tumorous liver and lung tissues were determined manually. This value was used as a threshold value for software-based lesion detection. The number of lesions detected, their SUV max , and their sizes in the x, y, and z-planes, as automatically provided by PET-CAD, were compared to visual lesion detection and manual measurements on CT. Results: The sensitivity for automated detection was 96% (86-99%) for colorectal liver metastases and 90% (70-99%) for lung lesions. The positive predictive value was 80% for liver and 68% for lung lesions. The mean SUV max of all lung lesions was 9.3 and 8.8 for the liver lesions. When assessed by PET-CAD, the mean lesion sizes for liver lesions in the x, y, and z-planes were 4.3 cm, 4.6 cm, and 4.2 cm compared to 3.5 cm, 3.8 cm, and 3.6 cm for manual measurements. The mean lesion sizes of lung lesions were 7.4 cm, 7.7 cm, and 8.4 cm in the x, y, and z-planes when assessed by PET-CAD compared to 5.8 cm, 6.1 cm, and 7.1 cm when measured manually. Using manual assessment, the lesion sizes were significantly smaller in all planes (p < 0.005). Conclusion: Software tools for automated lesion detection and assessment are expected to improve the clinical PET/CT workflow. Before implementation in the clinical routine, further improvements to the measurement accuracy are required. (orig.)

  5. Comparison of sensitivity and reading time for the use of computer-aided detection (CAD) of pulmonary nodules at MDCT as concurrent or second reader

    International Nuclear Information System (INIS)

    Beyer, F.; Zierott, L.; Juergens, K.U.; Heindel, W.; Fallenberg, E.M.; Stoeckel, J.; Wormanns, D.

    2007-01-01

    The purpose of this study was to compare sensitivity for detection of pulmonary nodules in MDCT scans and reading time of radiologists when using CAD as the second reader (SR) respectively concurrent reader (CR). Four radiologists analyzed 50 chest MDCT scans chosen from clinical routine two times and marked all detected pulmonary nodules: first with CAD as CR (display of CAD results immediately in the reading session) and later (median 14 weeks) with CAD as SR (display of CAD markers after completion of first reading without CAD). A Siemens LungCAD prototype was used. Sensitivities for detection of nodules and reading times were recorded. Sensitivity of reading with CAD as SR was significantly higher than reading without CAD (p < 0.001) and CAD as CR (p < 0.001). For nodule size of 1.75 mm or above no significant sensitivity difference between CAD as CR and reading without CAD was observed; e.g., for nodules above 4 mm sensitivity was 68% without CAD, 68% with CAD as CR (p 0.45) and 75% with CAD as SR (p < 0.001). Reading time was significantly shorter for CR (274 s) compared to reading without CAD (294 s; p = 0.04) and SR (337 s; p < 0.001). In our study CAD could either speed up reading of chest CT cases for pulmonary nodules without relevant loss of sensitivity when used as CR, or it increased sensitivity at the cost of longer reading times when used as SR. (orig.)

  6. Evaluation of computer-aided detection and diagnosis systems.

    Science.gov (United States)

    Petrick, Nicholas; Sahiner, Berkman; Armato, Samuel G; Bert, Alberto; Correale, Loredana; Delsanto, Silvia; Freedman, Matthew T; Fryd, David; Gur, David; Hadjiiski, Lubomir; Huo, Zhimin; Jiang, Yulei; Morra, Lia; Paquerault, Sophie; Raykar, Vikas; Samuelson, Frank; Summers, Ronald M; Tourassi, Georgia; Yoshida, Hiroyuki; Zheng, Bin; Zhou, Chuan; Chan, Heang-Ping

    2013-08-01

    Computer-aided detection and diagnosis (CAD) systems are increasingly being used as an aid by clinicians for detection and interpretation of diseases. Computer-aided detection systems mark regions of an image that may reveal specific abnormalities and are used to alert clinicians to these regions during image interpretation. Computer-aided diagnosis systems provide an assessment of a disease using image-based information alone or in combination with other relevant diagnostic data and are used by clinicians as a decision support in developing their diagnoses. While CAD systems are commercially available, standardized approaches for evaluating and reporting their performance have not yet been fully formalized in the literature or in a standardization effort. This deficiency has led to difficulty in the comparison of CAD devices and in understanding how the reported performance might translate into clinical practice. To address these important issues, the American Association of Physicists in Medicine (AAPM) formed the Computer Aided Detection in Diagnostic Imaging Subcommittee (CADSC), in part, to develop recommendations on approaches for assessing CAD system performance. The purpose of this paper is to convey the opinions of the AAPM CADSC members and to stimulate the development of consensus approaches and "best practices" for evaluating CAD systems. Both the assessment of a standalone CAD system and the evaluation of the impact of CAD on end-users are discussed. It is hoped that awareness of these important evaluation elements and the CADSC recommendations will lead to further development of structured guidelines for CAD performance assessment. Proper assessment of CAD system performance is expected to increase the understanding of a CAD system's effectiveness and limitations, which is expected to stimulate further research and development efforts on CAD technologies, reduce problems due to improper use, and eventually improve the utility and efficacy of CAD in

  7. Computer-aided detection (CAD) of solid pulmonary nodules in chest x-ray equivalent ultralow dose chest CT - first in-vivo results at dose levels of 0.13 mSv

    Energy Technology Data Exchange (ETDEWEB)

    Messerli, Michael, E-mail: Michael.Messerli@usz.ch [Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen (Switzerland); Kluckert, Thomas; Knitel, Meinhard [Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen (Switzerland); Rengier, Fabian [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg (Germany); Warschkow, René [Department of Surgery, Cantonal Hospital St. Gallen (Switzerland); Alkadhi, Hatem [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich (Switzerland); Leschka, Sebastian [Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen (Switzerland); Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University Zurich (Switzerland); Wildermuth, Simon; Bauer, Ralf W. [Division of Radiology and Nuclear Medicine, Cantonal Hospital St. Gallen (Switzerland)

    2016-12-15

    Highlights: • Computer-aided detection (CAD) of solid pulmonary nodules was compared in 202 patients in standard dose and ultralow dose CT. • The per–nodule sensitivity of CAD was 70% in standard dose CT and 68% in ultralow dose CT. • The per–nodule sensitivity of CAD in standard dose CT was similar to ultralow dose CT in all size subgroups (all p > 0.05). • Adding CAD markings in ultralow dose CT significantly improved the sensitivity of two radiologists from 77% to 88% and from 66% to 79%, respectively. • CAD can serve as an excellent second reader for nodule detection in CT even at dose levels similar to chest X-ray. - Abstract: Objectives: To determine the value of computer-aided detection (CAD) for solid pulmonary nodules in ultralow radiation dose single-energy computed tomography (CT) of the chest using third-generation dual-source CT at 100 kV and fixed tube current at 70 mAs with tin filtration. Methods: 202 consecutive patients undergoing clinically indicated standard dose chest CT (1.8 ± 0.7 mSv) were prospectively included and scanned with an additional ultralow dose CT (0.13 ± 0.01 mSv) in the same session. Standard of reference (SOR) was established by consensus reading of standard dose CT by two radiologists. CAD was performed in standard dose and ultralow dose CT with two different reconstruction kernels. CAD detection rate of nodules was evaluated including subgroups of different nodule sizes (<5, 5–7, >7 mm). Sensitivity was further analysed in multivariable mixed effects logistic regression. Results: The SOR included 279 solid nodules (mean diameter 4.3 ± 3.4 mm, range 1–24 mm). There was no significant difference in per–nodule sensitivity of CAD in standard dose with 70% compared to 68% in ultralow dose CT both overall and in different size subgroups (all p > 0.05). CAD led to a significant increase of sensitivity for both radiologists reading the ultralow dose CT scans (all p < 0.001). In multivariable analysis, the use

  8. Computer-aided detection (CAD) of solid pulmonary nodules in chest x-ray equivalent ultralow dose chest CT - first in-vivo results at dose levels of 0.13 mSv

    International Nuclear Information System (INIS)

    Messerli, Michael; Kluckert, Thomas; Knitel, Meinhard; Rengier, Fabian; Warschkow, René; Alkadhi, Hatem; Leschka, Sebastian; Wildermuth, Simon; Bauer, Ralf W.

    2016-01-01

    Highlights: • Computer-aided detection (CAD) of solid pulmonary nodules was compared in 202 patients in standard dose and ultralow dose CT. • The per–nodule sensitivity of CAD was 70% in standard dose CT and 68% in ultralow dose CT. • The per–nodule sensitivity of CAD in standard dose CT was similar to ultralow dose CT in all size subgroups (all p > 0.05). • Adding CAD markings in ultralow dose CT significantly improved the sensitivity of two radiologists from 77% to 88% and from 66% to 79%, respectively. • CAD can serve as an excellent second reader for nodule detection in CT even at dose levels similar to chest X-ray. - Abstract: Objectives: To determine the value of computer-aided detection (CAD) for solid pulmonary nodules in ultralow radiation dose single-energy computed tomography (CT) of the chest using third-generation dual-source CT at 100 kV and fixed tube current at 70 mAs with tin filtration. Methods: 202 consecutive patients undergoing clinically indicated standard dose chest CT (1.8 ± 0.7 mSv) were prospectively included and scanned with an additional ultralow dose CT (0.13 ± 0.01 mSv) in the same session. Standard of reference (SOR) was established by consensus reading of standard dose CT by two radiologists. CAD was performed in standard dose and ultralow dose CT with two different reconstruction kernels. CAD detection rate of nodules was evaluated including subgroups of different nodule sizes (<5, 5–7, >7 mm). Sensitivity was further analysed in multivariable mixed effects logistic regression. Results: The SOR included 279 solid nodules (mean diameter 4.3 ± 3.4 mm, range 1–24 mm). There was no significant difference in per–nodule sensitivity of CAD in standard dose with 70% compared to 68% in ultralow dose CT both overall and in different size subgroups (all p > 0.05). CAD led to a significant increase of sensitivity for both radiologists reading the ultralow dose CT scans (all p < 0.001). In multivariable analysis, the use

  9. Assessment of the Incremental Benefit of Computer-Aided Detection (CAD) for Interpretation of CT Colonography by Experienced and Inexperienced Readers

    Science.gov (United States)

    Boone, Darren; Mallett, Susan; McQuillan, Justine; Taylor, Stuart A.; Altman, Douglas G.; Halligan, Steve

    2015-01-01

    Objectives To quantify the incremental benefit of computer-assisted-detection (CAD) for polyps, for inexperienced readers versus experienced readers of CT colonography. Methods 10 inexperienced and 16 experienced radiologists interpreted 102 colonography studies unassisted and with CAD utilised in a concurrent paradigm. They indicated any polyps detected on a study sheet. Readers’ interpretations were compared against a ground-truth reference standard: 46 studies were normal and 56 had at least one polyp (132 polyps in total). The primary study outcome was the difference in CAD net benefit (a combination of change in sensitivity and change in specificity with CAD, weighted towards sensitivity) for detection of patients with polyps. Results Inexperienced readers’ per-patient sensitivity rose from 39.1% to 53.2% with CAD and specificity fell from 94.1% to 88.0%, both statistically significant. Experienced readers’ sensitivity rose from 57.5% to 62.1% and specificity fell from 91.0% to 88.3%, both non-significant. Net benefit with CAD assistance was significant for inexperienced readers but not for experienced readers: 11.2% (95%CI 3.1% to 18.9%) versus 3.2% (95%CI -1.9% to 8.3%) respectively. Conclusions Concurrent CAD resulted in a significant net benefit when used by inexperienced readers to identify patients with polyps by CT colonography. The net benefit was nearly four times the magnitude of that observed for experienced readers. Experienced readers did not benefit significantly from concurrent CAD. PMID:26355745

  10. Efficacy of computer-aided detection system for screening mammography

    International Nuclear Information System (INIS)

    Saito, Mioko; Ohnuki, Koji; Yamada, Takayuki; Saito, Haruo; Ishibashi, Tadashi; Ohuchi, Noriaki; Takahashi, Shoki

    2002-01-01

    A study was conducted to evaluate the efficacy of a computer-aided detection (CAD) system for screening mammography (MMG). Screening mammograms of 2,231 women aged over 50 yr were examined. Medio-lateral oblique (MLO) images were obtained, and two expert observers interpreted the mammograms by consensus. First, each mammogram was interpreted without the assistance of CAD, followed immediately by a re-evaluation of areas marked by the CAD system. Data were recorded to measure the effect of CAD on the recall rate, cancer detection rate and detection rate of masses, microcalcifications and other findings. The CAD system increased the recall rate from 2.3% to 2.6%. Six recalled cases were diagnosed as breast cancer pathologically, and CAD detected all of these lesions. Seven additional cases in which CAD detected abnormal findings had no malignancy. The detection rate of CAD for microcalcifications was high (95.0%). However, the detection rate for mass lesions and other findings was low (29.2% and 25.0% respectively). The false positivity rate was 0.13/film for microcalcifications, and 0.25/film for mass lesions. The efficacy of the CAD system for detecting microcalcifications on screening mammograms was confirmed. However, the low detection rate of mass lesions and relatively high rate of false positivity need to be further improved. (author)

  11. PACS-Based Computer-Aided Detection and Diagnosis

    Science.gov (United States)

    Huang, H. K. (Bernie); Liu, Brent J.; Le, Anh HongTu; Documet, Jorge

    The ultimate goal of Picture Archiving and Communication System (PACS)-based Computer-Aided Detection and Diagnosis (CAD) is to integrate CAD results into daily clinical practice so that it becomes a second reader to aid the radiologist's diagnosis. Integration of CAD and Hospital Information System (HIS), Radiology Information System (RIS) or PACS requires certain basic ingredients from Health Level 7 (HL7) standard for textual data, Digital Imaging and Communications in Medicine (DICOM) standard for images, and Integrating the Healthcare Enterprise (IHE) workflow profiles in order to comply with the Health Insurance Portability and Accountability Act (HIPAA) requirements to be a healthcare information system. Among the DICOM standards and IHE workflow profiles, DICOM Structured Reporting (DICOM-SR); and IHE Key Image Note (KIN), Simple Image and Numeric Report (SINR) and Post-processing Work Flow (PWF) are utilized in CAD-HIS/RIS/PACS integration. These topics with examples are presented in this chapter.

  12. Evaluation of the potential benefit of computer-aided diagnosis (CAD) for lung cancer screening using photofluorography

    International Nuclear Information System (INIS)

    Matsumoto, Tsuneo; Nakamura, Hiroshi; Nakanishi, Takashi; Doi, Kunio; Kano, Akiko.

    1993-01-01

    To evaluate the potential benefit of computer-aided diagnosis (CAD) in lung cancer screenings using photofluorographic films, we performed an observer test with 12 radiologists. We used 60 photofluorographic films obtained from a lung cancer screening program in Yamaguchi Prefecture (30 contained cancerous nodules and 30 had no nodules). In these cases, our current automated detection scheme achieved a sensitivity of 80%, but yielded an average of 11 false-positives per image. The observer study consisted of three viewing conditions: 1) only the original image (single reading), 2) the original image and computer output obtained from the current CAD scheme (CAD 1), 3) the original image and computer output obtained from a simulated improved CAD scheme with the same 80% true-positive rate, but with an average of one false-positive per image (CAD 2). Compared with double reading using independent interpretations, which is based on a higher score between two single readings, CAD 2 was more sensitive in subtle cases. The specificity of CAD was superior to that of double reading. Although CAD 1 (Az=0.805) was inferior to double reading (Az=0.837) in terms of the ROC curve, CAD 2 (Az=0.872) significantly improved the ROC curve and also significantly reduced observation time (p<0.05). If the number of false positives can be reduced, computer-aided diagnosis may play an important role in lung cancer screening programs. (author)

  13. A Multidisciplinary Research Team Approach to Computer-Aided Drafting (CAD) System Selection. Final Report.

    Science.gov (United States)

    Franken, Ken; And Others

    A multidisciplinary research team was assembled to review existing computer-aided drafting (CAD) systems for the purpose of enabling staff in the Design Drafting Department at Linn Technical College (Missouri) to select the best system out of the many CAD systems in existence. During the initial stage of the evaluation project, researchers…

  14. Article Commentary: Computer-Aided Detection of Breast Cancer — Have All Bases Been Covered?

    Directory of Open Access Journals (Sweden)

    Gautam S. Muralidhar

    2008-01-01

    Full Text Available The use of computer-aided detection (CAD systems in mammography has been the subject of intense research for many years. These systems have been developed with the aim of helping radiologists to detect signs of breast cancer. However, the effectiveness of CAD systems in practice has sparked recent debate. In this commentary, we argue that computer-aided detection will become an increasingly important tool for radiologists in the early detection of breast cancer, but there are some important issues that need to be given greater focus in designing CAD systems if they are to reach their full potential.

  15. Computer-aided detection in breast MRI : a systematic review and meta-analysis

    NARCIS (Netherlands)

    Dorrius, Monique D.; Jansen-van der Weide, Marijke C.; van Ooijen, Peter M. A.; Pijnappel, Ruud M.; Oudkerk, Matthijs

    To evaluate the additional value of computer-aided detection (CAD) in breast MRI by assessing radiologists' accuracy in discriminating benign from malignant breast lesions. A literature search was performed with inclusion of relevant studies using a commercially available CAD system with automatic

  16. COMPUTER-AIDED DETECTION OF ACINAR SHADOWS IN CHEST RADIOGRAPHS

    Directory of Open Access Journals (Sweden)

    Tao Xu

    2013-05-01

    Full Text Available Despite the technological advances in medical diagnosis, accurate detection of infectious tuberculosis (TB still poses challenges due to complex image features and thus infectious TB continues to be a public health problem of global proportions. Currently, the detection of TB is mainly conducted visually by radiologists examining chest radiographs (CXRs. To reduce the backlog of CXR examination and provide more precise quantitative assessment, computer-aided detection (CAD systems for potential lung lesions have been increasingly adopted and commercialized for clinical practice. CADs work as supporting tools to alert radiologists on suspected features that could have easily been neglected. In this paper, an effective CAD system aimed for acinar shadow regions detection in CXRs is proposed. This system exploits textural and photometric features analysis techniques which include local binary pattern (LBP, grey level co-occurrence matrix (GLCM and histogram of oriented gradients (HOG to analyze target regions in CXRs. Classification of acinar shadows using Adaboost is then deployed to verify the performance of a combination of these techniques. Comparative study in different image databases shows that the proposed CAD system delivers consistent high accuracy in detecting acinar shadows.

  17. Reproducibility of computer-aided detection system in digital mammograms

    International Nuclear Information System (INIS)

    Kim, Seung Ja; Cho, Nariya; Cha, Joo Hee; Chung, Hye Kyung; Lee, Sin Ho; Cho, Kyung Soo; Kim, Sun Mi; Moon, Woo Kyung

    2005-01-01

    To evaluate the reproducibility of the computer-aided detection (CAD) system for digital mammograms. We applied the CAD system (ImageChecker M1000-DM, version 3.1; R2 Technology) to full field digital mammograms. These mammograms were taken twice at an interval of 10-45 days (mean:25 days) for 34 preoperative patients (breast cancer n=27, benign disease n=7, age range:20-66 years, mean age:47.9 years). On the mammograms, lesions were visible in 19 patients and these were depicted as 15 masses and 12 calcification clusters. We analyzed the sensitivity, the false positive rate (FPR) and the reproducibility of the CAD marks. The broader sensitivities of the CAD system were 80% (12 of 15), 67%(10 of 15) for masses and those for calcification clusters were 100% (12 of 12). The strict sensitivities were 50% (15 of 30) and 50% (15 of 30) for masses and 92% (22 of 24) and 79% (19 of 24) for the clusters. The FPR for the masses was 0.21-0.22/image, the FPR for the clusters was 0.03-0.04/image and the total FPR was 0.24-0.26/image. Among 132 mammography images, the identical images regardless of the existence of CAD marks were 59% (78 of 132), and the identical images with CAD marks were 22% (15 of 69). The reproducibility of the CAD marks for the true positive mass was 67% (12 of 18) and 71% (17 of 24) for the true positive cluster. The reproducibility of CAD marks for the false positive mass was 8% (4 of 53), and the reproducibility of CAD marks for the false positive clusters was 14% (1 of 7). The reproducibility of the total mass marks was 23% (16 of 71), and the reproducibility of the total cluster marks was 58% (18 of 31). CAD system showed higher sensitivity and reproducibility of CAD marks for the calcification clusters which are related to breast cancer. Yet the overall reproducibility of CAD marks was low; therefore, the CAD system must be applied considering this limitation

  18. Computer-aided diagnosis (CAD) of subsolid nodules: Evaluation of a commercial CAD system

    International Nuclear Information System (INIS)

    Benzakoun, Joseph; Bommart, Sébastien; Coste, Joël; Chassagnon, Guillaume; Lederlin, Mathieu; Boussouar, Samia

    2016-01-01

    Highlights: • CAD sensitivity is still limited for automated detection of subsolid nodules. • CAD detection rate is higher for part-solid than for pure ground-glass nodules. • Part-solid nodule detection is not better for nodules with larger solid component. - Abstract: Objectives: To evaluate the performance of a commercially available CAD system for automated detection and measurement of subsolid nodules. Materials and methods: The CAD system was tested on 50 pure ground-glass and 50 part-solid nodules (median diameter: 17 mm) previously found on standard-dose CT scans in 100 different patients. True nodule detection and the total number of CAD marks were evaluated at different sensitivity settings. The influence of nodule and CT acquisition characteristics was analyzed with logistic regression. Software and manually measured diameters were compared with Spearman and Bland-Altman methods. Results: With sensitivity adjusted for 3-mm nodule detection, 50/100 (50%) subsolid nodules were detected, at the average cost of 17 CAD marks per CT. These figures were respectively 26/100 (26%) and 2 at the 5-mm setting. At the highest sensitivity setting (2-mm nodule detection), the average number of CAD marks per CT was 41 but the nodule detection rate only increased to 54%. Part–solid nodules were better detected than pure ground glass nodules: 36/50 (72%) versus 14/50 (28%) at the 3-mm setting (p < 0.0001), with no influence of the solid component size. Except for the type (i.e. part solid or pure ground glass), no other nodule characteristic influenced the detection rate. High-quality segmentation was obtained for 79 nodules, which for automated measurements correlated well with manual measurements (rho = 0.90[0.84–0.93]). All part-solid nodules had software-measured attenuation values above −671 Hounsfield units (HU). Conclusion: The detection rate of subsolid nodules by this CAD system was insufficient, but high-quality segmentation was obtained in 79% of

  19. Computer-aided diagnosis (CAD) of subsolid nodules: Evaluation of a commercial CAD system

    Energy Technology Data Exchange (ETDEWEB)

    Benzakoun, Joseph, E-mail: benzakoun.joseph@gmail.com [Hôpital Hôtel-Dieu, 1 parvis Notre-Dame, 75004 Paris (France); Université Paris Descartes, 12 rue de l’Ecole de Médecine, 75006 Paris (France); Bommart, Sébastien, E-mail: s-bommart@chu-montpellier.fr [CHU de Montpellier, 191 avenue du Doyen Gaston Giraud, 34000 Montpellier (France); INSERM U 1046, 371 avenue du Doyen G. Giraud, 34000 Montpellier (France); Coste, Joël, E-mail: joel.coste@htd.aphp.fr [Hôpital Hôtel-Dieu, 1 parvis Notre-Dame, 75004 Paris (France); Université Paris Descartes, 12 rue de l’Ecole de Médecine, 75006 Paris (France); Chassagnon, Guillaume, E-mail: gchassagnon@gmail.com [Université Paris Descartes, 12 rue de l’Ecole de Médecine, 75006 Paris (France); Hôpital Cochin, Radiologie, 27 rue du Faubourg Saint Jacques, 75014 Paris (France); Lederlin, Mathieu, E-mail: mathieu.lederlin@chu-rennes.fr [CHU de Rennes, Radiologie, 2 Rue Henri le Guilloux, 35000 Rennes (France); Université de Rennes 1, 9 Rue Jean Macé, 35000 Rennes (France); Boussouar, Samia, E-mail: samiaboussouar@gmail.com [Université Paris Descartes, 12 rue de l’Ecole de Médecine, 75006 Paris (France); Hôpital Européen Georges Pompidou, 20 Rue Leblanc, 75015 Paris (France); and others

    2016-10-15

    Highlights: • CAD sensitivity is still limited for automated detection of subsolid nodules. • CAD detection rate is higher for part-solid than for pure ground-glass nodules. • Part-solid nodule detection is not better for nodules with larger solid component. - Abstract: Objectives: To evaluate the performance of a commercially available CAD system for automated detection and measurement of subsolid nodules. Materials and methods: The CAD system was tested on 50 pure ground-glass and 50 part-solid nodules (median diameter: 17 mm) previously found on standard-dose CT scans in 100 different patients. True nodule detection and the total number of CAD marks were evaluated at different sensitivity settings. The influence of nodule and CT acquisition characteristics was analyzed with logistic regression. Software and manually measured diameters were compared with Spearman and Bland-Altman methods. Results: With sensitivity adjusted for 3-mm nodule detection, 50/100 (50%) subsolid nodules were detected, at the average cost of 17 CAD marks per CT. These figures were respectively 26/100 (26%) and 2 at the 5-mm setting. At the highest sensitivity setting (2-mm nodule detection), the average number of CAD marks per CT was 41 but the nodule detection rate only increased to 54%. Part–solid nodules were better detected than pure ground glass nodules: 36/50 (72%) versus 14/50 (28%) at the 3-mm setting (p < 0.0001), with no influence of the solid component size. Except for the type (i.e. part solid or pure ground glass), no other nodule characteristic influenced the detection rate. High-quality segmentation was obtained for 79 nodules, which for automated measurements correlated well with manual measurements (rho = 0.90[0.84–0.93]). All part-solid nodules had software-measured attenuation values above −671 Hounsfield units (HU). Conclusion: The detection rate of subsolid nodules by this CAD system was insufficient, but high-quality segmentation was obtained in 79% of

  20. Multi-site evaluation of a computer aided detection (CAD) algorithm for small acute intra-cranial hemorrhage and development of a stand-alone CAD system ready for deployment in a clinical environment

    Science.gov (United States)

    Deshpande, Ruchi R.; Fernandez, James; Lee, Joon K.; Chan, Tao; Liu, Brent J.; Huang, H. K.

    2010-03-01

    Timely detection of Acute Intra-cranial Hemorrhage (AIH) in an emergency environment is essential for the triage of patients suffering from Traumatic Brain Injury. Moreover, the small size of lesions and lack of experience on the reader's part could lead to difficulties in the detection of AIH. A CT based CAD algorithm for the detection of AIH has been developed in order to improve upon the current standard of identification and treatment of AIH. A retrospective analysis of the algorithm has already been carried out with 135 AIH CT studies with 135 matched normal head CT studies from the Los Angeles County General Hospital/ University of Southern California Hospital System (LAC/USC). In the next step, AIH studies have been collected from Walter Reed Army Medical Center, and are currently being processed using the AIH CAD system as part of implementing a multi-site assessment and evaluation of the performance of the algorithm. The sensitivity and specificity numbers from the Walter Reed study will be compared with the numbers from the LAC/USC study to determine if there are differences in the presentation and detection due to the difference in the nature of trauma between the two sites. Simultaneously, a stand-alone system with a user friendly GUI has been developed to facilitate implementation in a clinical setting.

  1. ROCK-CAD - computer aided geological modelling system

    International Nuclear Information System (INIS)

    Saksa, P.

    1995-12-01

    The study discusses surface and solid modelling methods, their use and interfacing with geodata. Application software named ROCK-CAD suitable for geological bedrock modelling has been developed with support from Teollisuuden Voima Oy (TVO). It has been utilized in the Finnish site characterization programme for spent nuclear fuel waste disposal during the 1980s and 1990s. The system is based on the solid modelling technique. It comprises also rich functionality for the particular geological modelling scheme. The ROCK-CAD system provides, among other things, varying graphical vertical and horizontal intersections and perspective illustrations. The specially developed features are the application of the boundary representation modelling method, parametric object generation language and the discipline approach. The ROCK-CAD system has been utilized in modelling spatial distribution of rock types and fracturing structures in TVO's site characterization. The Olkiluoto site at Eurajoki serves as an example case. The study comprises the description of the modelling process, models and illustration examples. The utilization of bedrock models in site characterization, in tentative repository siting as well as in groundwater flow simulation is depicted. The application software has improved the assessment of the sites studied, given a new basis for the documentation of interpretation and modelling work, substituted hand-drawing and enabled digital transfer to numerical analysis. Finally, aspects of presentation graphics in geological modelling are considered. (84 refs., 30 figs., 11 tabs.)

  2. Evolution of facility layout requirements and CAD [computer-aided design] system development

    International Nuclear Information System (INIS)

    Jones, M.

    1990-06-01

    The overall configuration of the Superconducting Super Collider (SSC) including the infrastructure and land boundary requirements were developed using a computer-aided design (CAD) system. The evolution of the facility layout requirements and the use of the CAD system are discussed. The emphasis has been on minimizing the amount of input required and maximizing the speed by which the output may be obtained. The computer system used to store the data is also described

  3. 3D computer-aided detection for digital breast tomosynthesis: Comparison with 2D computer-aided detection for digital mammography in the detection of calcifications

    Energy Technology Data Exchange (ETDEWEB)

    Chu, A Jung; Cho, Nariya; Chang, Jung Min; Kim, Won Hwa; Lee, Su Hyun; Song, Sung Eun; Shin, Sung Ui; Moon, Woo Kyung [Dept. of Radiology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-08-15

    To retrospectively evaluate the performance of 3D computer-aided detection (CAD) for digital breast tomosynthesis (DBT) in the detection of calcifications in comparison with 2D CAD for digital mammography (DM). Between 2012 and 2013, both 3D CAD and 2D CAD systems were retrospectively applied to the calcification data set including 69 calcifications (31 malignant calcifications and 38 benign calcifications) and the normal data set including 20 bilateral normal mammograms. Each data set consisted of paired DBT and DM images. Sensitivities for the detection of malignant calcifications were calculated from the calcification data set. False-positive mark rates were calculated from the normal data set. They were compared between the two systems. Sensitivities of 3D CAD [100% (31/31) at levels 2, 1, and 0] were same as those of the 2D CAD system [100% (31/31) at levels 2 and 1] (p = 1.0, respectively). The mean value of false-positive marks per view with 3D CAD was higher than that with 2D CAD at level 2 (0.52 marks ± 0.91 vs. 0.07 marks ± 0.26, p = 0.009). 3D CAD for DBT showed equivalent sensitivity, albeit with a higher false-positive mark rate, than 2D CAD for DM in the detection of calcifications.

  4. Computer-Aided Detection of Polyps in CT Colonography Using Logistic Regression

    NARCIS (Netherlands)

    Van Ravesteijn, V.F.; Van Wijk, C.; Vos, F.M.; Truyen, R.; Peters, J.F.; Stoker, J.; Van Vliet, L.J.

    2010-01-01

    We present a computer-aided detection (CAD) system for computed tomography colonography that orders the polyps according to clinical relevance. TheCADsystem consists of two steps: candidate detection and supervised classification. The characteristics of the detection step lead to specific choices

  5. Computer-aided Detection of Lung Cancer on Chest Radiographs: Effect on Observer Performance

    NARCIS (Netherlands)

    de Hoop, Bartjan; de Boo, Diederik W.; Gietema, Hester A.; van Hoorn, Frans; Mearadji, Banafsche; Schijf, Laura; van Ginneken, Bram; Prokop, Mathias; Schaefer-Prokop, Cornelia

    2010-01-01

    Purpose: To assess how computer-aided detection (CAD) affects reader performance in detecting early lung cancer on chest radiographs. Materials and Methods: In this ethics committee-approved study, 46 individuals with 49 computed tomographically (CT)-detected and histologically proved lung cancers

  6. Observer training for computer-aided detection of pulmonary nodules in chest radiography

    NARCIS (Netherlands)

    de Boo, Diederick W.; van Hoorn, François; van Schuppen, Joost; Schijf, Laura; Scheerder, Maeke J.; Freling, Nicole J.; Mets, Onno; Weber, Michael; Schaefer-Prokop, Cornelia M.

    2012-01-01

    To assess whether short-term feedback helps readers to increase their performance using computer-aided detection (CAD) for nodule detection in chest radiography. The 140 CXRs (56 with a solitary CT-proven nodules and 84 negative controls) were divided into four subsets of 35; each were read in a

  7. Does Computer-aided Detection Assist in the Early Detection of Breast Cancer?

    International Nuclear Information System (INIS)

    Hukkinen, K.; Pamilo, M.

    2005-01-01

    Purpose: To evaluate whether breast cancers detected at screening are visible in previous mammograms, and to assess the performance of a computer-aided detection (CAD) system in detecting lesions in preoperative and previous mammograms. Material and Methods: Initial screening detected 67 women with 69 surgically verified breast cancers (Group A). An experienced screening radiologist retrospectively analyzed previous mammograms for visible lesions (Group B), noting in particular their size and morphology. Preoperative and previous mammograms were analyzed with CAD; a relatively inexperienced resident also analyzed previous mammograms. The performances of CAD and resident were then compared. Results: Of the 69 lesions identified, 36 were visible in previous mammograms. Of these 36 'missed' lesions, 14 were under 10 mm in diameter and 29 were mass lesions. The sensitivity of CAD was 81% in Group A and 64% in Group B. Small mass lesions were harder for CAD to detect. The specificity of CAD was 3% in Group A and 9% in Group B. Together, CAD and the resident found more 'missed' lesions than separately. Conclusion: Of the 69 breast cancers, 36 were visible in previous mammograms. CAD's sensitivity in detecting cancer lesions ranged from 64% to 81%, while specificity ranged from 9% to as low as 3%. CAD may be helpful if the radiologist is less subspecialized in mammography

  8. Computer Aided Design in FE. Some Suggestions on the Inclusion of CAD Topics in Mechanical Engineering Courses. An Occasional Paper.

    Science.gov (United States)

    Ingham, P. C.

    This report investigates the feasibility of including computer aided design (CAD) materials in engineering courses. Section 1 briefly discusses the inevitability of CAD being adopted widely by British industry and the consequent need for its inclusion in engineering syllabi at all levels. A short description of what is meant by CAD follows in…

  9. Computer-Aided Detection in Breast Magnetic Resonance Imaging: A Review

    NARCIS (Netherlands)

    Dorrius, M. D.; Van Ooijen, P.M.A.

    2008-01-01

    The aim of this study is to give an overview on the accuracy of the discrimination between benign and malignant breast lesions on MRI with and without the use of a computer-aided detection (CAD) system. One investigator selected relevant articles based on title and abstract. Ten articles were

  10. On Combining Multiple-Instance Learning and Active Learning for Computer-Aided Detection of Tuberculosis

    NARCIS (Netherlands)

    Melendez Rodriguez, J.C.; Ginneken, B. van; Maduskar, P.; Philipsen, R.H.H.M.; Ayles, H.; Sanchez, C.I.

    2016-01-01

    The major advantage of multiple-instance learning (MIL) applied to a computer-aided detection (CAD) system is that it allows optimizing the latter with case-level labels instead of accurate lesion outlines as traditionally required for a supervised approach. As shown in previous work, a MIL-based

  11. Computer aided detection of surgical retained foreign object for prevention

    International Nuclear Information System (INIS)

    Hadjiiski, Lubomir; Marentis, Theodore C.; Rondon, Lucas; Chan, Heang-Ping; Chaudhury, Amrita R.; Chronis, Nikolaos

    2015-01-01

    Purpose: Surgical retained foreign objects (RFOs) have significant morbidity and mortality. They are associated with approximately $1.5 × 10 9 annually in preventable medical costs. The detection accuracy of radiographs for RFOs is a mediocre 59%. The authors address the RFO problem with two complementary technologies: a three-dimensional (3D) gossypiboma micro tag, the μTag that improves the visibility of RFOs on radiographs, and a computer aided detection (CAD) system that detects the μTag. It is desirable for the CAD system to operate in a high specificity mode in the operating room (OR) and function as a first reader for the surgeon. This allows for fast point of care results and seamless workflow integration. The CAD system can also operate in a high sensitivity mode as a second reader for the radiologist to ensure the highest possible detection accuracy. Methods: The 3D geometry of the μTag produces a similar two dimensional (2D) depiction on radiographs regardless of its orientation in the human body and ensures accurate detection by a radiologist and the CAD. The authors created a data set of 1800 cadaver images with the 3D μTag and other common man-made surgical objects positioned randomly. A total of 1061 cadaver images contained a single μTag and the remaining 739 were without μTag. A radiologist marked the location of the μTag using an in-house developed graphical user interface. The data set was partitioned into three independent subsets: a training set, a validation set, and a test set, consisting of 540, 560, and 700 images, respectively. A CAD system with modules that included preprocessing μTag enhancement, labeling, segmentation, feature analysis, classification, and detection was developed. The CAD system was developed using the training and the validation sets. Results: On the training set, the CAD achieved 81.5% sensitivity with 0.014 false positives (FPs) per image in a high specificity mode for the surgeons in the OR and 96

  12. Computer Aided Diagnosis System for Early Lung Cancer Detection

    Directory of Open Access Journals (Sweden)

    Fatma Taher

    2015-11-01

    Full Text Available Lung cancer continues to rank as the leading cause of cancer deaths worldwide. One of the most promising techniques for early detection of cancerous cells relies on sputum cell analysis. This was the motivation behind the design and the development of a new computer aided diagnosis (CAD system for early detection of lung cancer based on the analysis of sputum color images. The proposed CAD system encompasses four main processing steps. First is the preprocessing step which utilizes a Bayesian classification method using histogram analysis. Then, in the second step, mean shift segmentation is applied to segment the nuclei from the cytoplasm. The third step is the feature analysis. In this step, geometric and chromatic features are extracted from the nucleus region. These features are used in the diagnostic process of the sputum images. Finally, the diagnosis is completed using an artificial neural network and support vector machine (SVM for classifying the cells into benign or malignant. The performance of the system was analyzed based on different criteria such as sensitivity, specificity and accuracy. The evaluation was carried out using Receiver Operating Characteristic (ROC curve. The experimental results demonstrate the efficiency of the SVM classifier over other classifiers, with 97% sensitivity and accuracy as well as a significant reduction in the number of false positive and false negative rates.

  13. Observer training for computer-aided detection of pulmonary nodules in chest radiography.

    Science.gov (United States)

    De Boo, Diederick W; van Hoorn, François; van Schuppen, Joost; Schijf, Laura; Scheerder, Maeke J; Freling, Nicole J; Mets, Onno; Weber, Michael; Schaefer-Prokop, Cornelia M

    2012-08-01

    To assess whether short-term feedback helps readers to increase their performance using computer-aided detection (CAD) for nodule detection in chest radiography. The 140 CXRs (56 with a solitary CT-proven nodules and 84 negative controls) were divided into four subsets of 35; each were read in a different order by six readers. Lesion presence, location and diagnostic confidence were scored without and with CAD (IQQA-Chest, EDDA Technology) as second reader. Readers received individual feedback after each subset. Sensitivity, specificity and area under the receiver-operating characteristics curve (AUC) were calculated for readings with and without CAD with respect to change over time and impact of CAD. CAD stand-alone sensitivity was 59 % with 1.9 false-positives per image. Mean AUC slightly increased over time with and without CAD (0.78 vs. 0.84 with and 0.76 vs. 0.82 without CAD) but differences did not reach significance. The sensitivity increased (65 % vs. 70 % and 66 % vs. 70 %) and specificity decreased over time (79 % vs. 74 % and 80 % vs. 77 %) but no significant impact of CAD was found. Short-term feedback does not increase the ability of readers to differentiate true- from false-positive candidate lesions and to use CAD more effectively. • Computer-aided detection (CAD) is increasingly used as an adjunct for many radiological techniques. • Short-term feedback does not improve reader performance with CAD in chest radiography. • Differentiation between true- and false-positive CAD for low conspicious possible lesions proves difficult. • CAD can potentially increase reader performance for nodule detection in chest radiography.

  14. Improved cancer detection in automated breast ultrasound by radiologists using Computer Aided Detection

    Energy Technology Data Exchange (ETDEWEB)

    Zelst, J.C.M. van, E-mail: Jan.vanZelst@radboudumc.nl [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Tan, T.; Platel, B. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Jong, M. de [Jeroen Bosch Medical Centre, Department of Radiology, ‘s-Hertogenbosch (Netherlands); Steenbakkers, A. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Mourits, M. [Jeroen Bosch Medical Centre, Department of Radiology, ‘s-Hertogenbosch (Netherlands); Grivegnee, A. [Jules Bordet Institute, Department of Radiology, Brussels (Belgium); Borelli, C. [Catholic University of the Sacred Heart, Department of Radiological Sciences, Rome (Italy); Karssemeijer, N.; Mann, R.M. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands)

    2017-04-15

    Objective: To investigate the effect of dedicated Computer Aided Detection (CAD) software for automated breast ultrasound (ABUS) on the performance of radiologists screening for breast cancer. Methods: 90 ABUS views of 90 patients were randomly selected from a multi-institutional archive of cases collected between 2010 and 2013. This dataset included normal cases (n = 40) with >1 year of follow up, benign (n = 30) lesions that were either biopsied or remained stable, and malignant lesions (n = 20). Six readers evaluated all cases with and without CAD in two sessions. CAD-software included conventional CAD-marks and an intelligent minimum intensity projection of the breast tissue. Readers reported using a likelihood-of-malignancy scale from 0 to 100. Alternative free-response ROC analysis was used to measure the performance. Results: Without CAD, the average area-under-the-curve (AUC) of the readers was 0.77 and significantly improved with CAD to 0.84 (p = 0.001). Sensitivity of all readers improved (range 5.2–10.6%) by using CAD but specificity decreased in four out of six readers (range 1.4–5.7%). No significant difference was observed in the AUC between experienced radiologists and residents both with and without CAD. Conclusions: Dedicated CAD-software for ABUS has the potential to improve the cancer detection rates of radiologists screening for breast cancer.

  15. Improved cancer detection in automated breast ultrasound by radiologists using Computer Aided Detection

    International Nuclear Information System (INIS)

    Zelst, J.C.M. van; Tan, T.; Platel, B.; Jong, M. de; Steenbakkers, A.; Mourits, M.; Grivegnee, A.; Borelli, C.; Karssemeijer, N.; Mann, R.M.

    2017-01-01

    Objective: To investigate the effect of dedicated Computer Aided Detection (CAD) software for automated breast ultrasound (ABUS) on the performance of radiologists screening for breast cancer. Methods: 90 ABUS views of 90 patients were randomly selected from a multi-institutional archive of cases collected between 2010 and 2013. This dataset included normal cases (n = 40) with >1 year of follow up, benign (n = 30) lesions that were either biopsied or remained stable, and malignant lesions (n = 20). Six readers evaluated all cases with and without CAD in two sessions. CAD-software included conventional CAD-marks and an intelligent minimum intensity projection of the breast tissue. Readers reported using a likelihood-of-malignancy scale from 0 to 100. Alternative free-response ROC analysis was used to measure the performance. Results: Without CAD, the average area-under-the-curve (AUC) of the readers was 0.77 and significantly improved with CAD to 0.84 (p = 0.001). Sensitivity of all readers improved (range 5.2–10.6%) by using CAD but specificity decreased in four out of six readers (range 1.4–5.7%). No significant difference was observed in the AUC between experienced radiologists and residents both with and without CAD. Conclusions: Dedicated CAD-software for ABUS has the potential to improve the cancer detection rates of radiologists screening for breast cancer.

  16. Standalone computer-aided detection compared to radiologists' performance for the detection of mammographic masses

    International Nuclear Information System (INIS)

    Hupse, Rianne; Samulski, Maurice; Imhof-Tas, Mechli W.; Karssemeijer, Nico; Lobbes, Marc; Boetes, Carla; Heeten, Ard den; Beijerinck, David; Pijnappel, Ruud

    2013-01-01

    We developed a computer-aided detection (CAD) system aimed at decision support for detection of malignant masses and architectural distortions in mammograms. The effect of this system on radiologists' performance depends strongly on its standalone performance. The purpose of this study was to compare the standalone performance of this CAD system to that of radiologists. In a retrospective study, nine certified screening radiologists and three residents read 200 digital screening mammograms without the use of CAD. Performances of the individual readers and of CAD were computed as the true-positive fraction (TPF) at a false-positive fraction of 0.05 and 0.2. Differences were analysed using an independent one-sample t-test. At a false-positive fraction of 0.05, the performance of CAD (TPF = 0.487) was similar to that of the certified screening radiologists (TPF = 0.518, P = 0.17). At a false-positive fraction of 0.2, CAD performance (TPF = 0.620) was significantly lower than the radiologist performance (TPF = 0.736, P <0.001). Compared to the residents, CAD performance was similar for all false-positive fractions. The sensitivity of CAD at a high specificity was comparable to that of human readers. These results show potential for CAD to be used as an independent reader in breast cancer screening. (orig.)

  17. Effect of computer-aided detection as a second reader in multidetector-row CT colonography

    International Nuclear Information System (INIS)

    Mang, Thomas; Peloschek, Philipp; Plank, Christina; Maier, Andrea; Weber, Michael; Herold, Christian; Schima, Wolfgang; Graser, Anno; Bogoni, Luca

    2007-01-01

    Our purpose was to assess the effect of computer-aided detection (CAD) on lesion detection as a second reader in computed tomographic colonography, and to compare the influence of CAD on the performance of readers with different levels of expertise. Fifty-two CT colonography patient data-sets (37 patients: 55 endoscopically confirmed polyps ≥0.5 cm, seven cancers; 15 patients: no abnormalities) were retrospectively reviewed by four radiologists (two expert, two nonexpert). After primary data evaluation, a second reading augmented with findings of CAD (polyp-enhanced view, Siemens) was performed. Sensitivities and reading time were calculated for each reader without CAD and supported by CAD findings. The sensitivity of expert readers was 91% each, and of nonexpert readers, 76% and 75%, respectively, for polyp detection. CAD increased the sensitivity of expert readers to 96% (P = 0.25) and 93% (P = 1), and that of nonexpert readers to 91% (P = 0.008) and 95% (P = 0.001), respectively. All four readers diagnosed 100% of cancers, but CAD alone only 43%. CAD increased reading time by 2.1 min (mean). CAD as a second reader significantly improves sensitivity for polyp detection in a high disease prevalence population for nonexpert readers. CAD causes a modest increase in reading time. CAD is of limited value in the detection of cancer. (orig.)

  18. Computer-aided-detection marker value and breast density in the detection of invasive lobular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Destounis, Stamatia; Hanson, Sarah [The Elizabeth Wende Breast Clinic, Rochester, NY (United States); Roehrig, Jimmy [R2/Hologic, Inc., Santa Clara, CA (United States)

    2007-08-15

    Invasive Lobular Carcinoma (ILC) is frequently a mammographic and diagnostic dilemma; thus any additional information that CAD (Computer-Aided Detection) systems can give radiologists may be helpful. Our study was to evaluate the role of CAD numeric values as indicators of malignancy and the effect of breast density in the diagnosis of ILC. Eighty consecutive biopsy-proven ILC cases with CAD (ImageChecker {sup registered}, Hologic vertical stroke R2, Santa Clara, CA, versions 2.3, 3.1, 3.2, 5.0, 5.2) diagnosed between June 2002 and December 2004 were retrospectively reviewed. Data included: BIRADS {sup registered} breast density, whether CAD marked the cancer at diagnosis year or years prior, and lesion type. Study mammograms underwent additional CAD scans (Image Checker {sup registered} V5.3, V8.0, V8.1) to obtain a numeric value associated with each marker, low values represent increasingly suspicious features. CAD correctly marked 65% (52/80) of ILC cases, detection was found to decrease with increased breast density. Numeric values of CAD marks at sites of carcinoma showed median score of 171 (range 0 - 1121). The CAD marker may potentially be used as an additional indicator of suspicious lesion features in all breast densities and higher likelihood that an area on the mammogram requires further investigation. (orig.)

  19. Computer-aided-detection marker value and breast density in the detection of invasive lobular carcinoma

    International Nuclear Information System (INIS)

    Destounis, Stamatia; Hanson, Sarah; Roehrig, Jimmy

    2007-01-01

    Invasive Lobular Carcinoma (ILC) is frequently a mammographic and diagnostic dilemma; thus any additional information that CAD (Computer-Aided Detection) systems can give radiologists may be helpful. Our study was to evaluate the role of CAD numeric values as indicators of malignancy and the effect of breast density in the diagnosis of ILC. Eighty consecutive biopsy-proven ILC cases with CAD (ImageChecker registered , Hologic vertical stroke R2, Santa Clara, CA, versions 2.3, 3.1, 3.2, 5.0, 5.2) diagnosed between June 2002 and December 2004 were retrospectively reviewed. Data included: BIRADS registered breast density, whether CAD marked the cancer at diagnosis year or years prior, and lesion type. Study mammograms underwent additional CAD scans (Image Checker registered V5.3, V8.0, V8.1) to obtain a numeric value associated with each marker, low values represent increasingly suspicious features. CAD correctly marked 65% (52/80) of ILC cases, detection was found to decrease with increased breast density. Numeric values of CAD marks at sites of carcinoma showed median score of 171 (range 0 - 1121). The CAD marker may potentially be used as an additional indicator of suspicious lesion features in all breast densities and higher likelihood that an area on the mammogram requires further investigation. (orig.)

  20. Local pulmonary structure classification for computer-aided nodule detection

    Science.gov (United States)

    Bahlmann, Claus; Li, Xianlin; Okada, Kazunori

    2006-03-01

    We propose a new method of classifying the local structure types, such as nodules, vessels, and junctions, in thoracic CT scans. This classification is important in the context of computer aided detection (CAD) of lung nodules. The proposed method can be used as a post-process component of any lung CAD system. In such a scenario, the classification results provide an effective means of removing false positives caused by vessels and junctions thus improving overall performance. As main advantage, the proposed solution transforms the complex problem of classifying various 3D topological structures into much simpler 2D data clustering problem, to which more generic and flexible solutions are available in literature, and which is better suited for visualization. Given a nodule candidate, first, our solution robustly fits an anisotropic Gaussian to the data. The resulting Gaussian center and spread parameters are used to affine-normalize the data domain so as to warp the fitted anisotropic ellipsoid into a fixed-size isotropic sphere. We propose an automatic method to extract a 3D spherical manifold, containing the appropriate bounding surface of the target structure. Scale selection is performed by a data driven entropy minimization approach. The manifold is analyzed for high intensity clusters, corresponding to protruding structures. Techniques involve EMclustering with automatic mode number estimation, directional statistics, and hierarchical clustering with a modified Bhattacharyya distance. The estimated number of high intensity clusters explicitly determines the type of pulmonary structures: nodule (0), attached nodule (1), vessel (2), junction (>3). We show accurate classification results for selected examples in thoracic CT scans. This local procedure is more flexible and efficient than current state of the art and will help to improve the accuracy of general lung CAD systems.

  1. Web-based computer-aided-diagnosis (CAD) system for bone age assessment (BAA) of children

    Science.gov (United States)

    Zhang, Aifeng; Uyeda, Joshua; Tsao, Sinchai; Ma, Kevin; Vachon, Linda A.; Liu, Brent J.; Huang, H. K.

    2008-03-01

    Bone age assessment (BAA) of children is a clinical procedure frequently performed in pediatric radiology to evaluate the stage of skeletal maturation based on a left hand and wrist radiograph. The most commonly used standard: Greulich and Pyle (G&P) Hand Atlas was developed 50 years ago and exclusively based on Caucasian population. Moreover, inter- & intra-observer discrepancies using this method create a need of an objective and automatic BAA method. A digital hand atlas (DHA) has been collected with 1,400 hand images of normal children from Asian, African American, Caucasian and Hispanic descends. Based on DHA, a fully automatic, objective computer-aided-diagnosis (CAD) method was developed and it was adapted to specific population. To bring DHA and CAD method to the clinical environment as a useful tool in assisting radiologist to achieve higher accuracy in BAA, a web-based system with direct connection to a clinical site is designed as a novel clinical implementation approach for online and real time BAA. The core of the system, a CAD server receives the image from clinical site, processes it by the CAD method and finally, generates report. A web service publishes the results and radiologists at the clinical site can review it online within minutes. This prototype can be easily extended to multiple clinical sites and will provide the foundation for broader use of the CAD system for BAA.

  2. Computer Aided Detection of Breast Masses in Digital Tomosynthesis

    National Research Council Canada - National Science Library

    Singh, Swatee; Lo, Joseph

    2008-01-01

    The purpose of this study was to investigate feasibility of computer-aided detection of masses and calcification clusters in breast tomosynthesis images and obtain reliable estimates of sensitivity...

  3. Importance Of Fashion Cad Computer Aided Design Study For Garment Industry In Bangladesh..

    Directory of Open Access Journals (Sweden)

    Md. Tabraz

    2017-10-01

    Full Text Available The garment industry is rapidly growing with new concepts for keeping fashion business alive. To survive in the fashion industry new innovations are necessary for a while. In order to meet the demands for the market a computer-aided design CAD system gives opportunity for mass customization in fashion. The system enables to create more styles random changes make new design dimension of collection pattern generation graded size pattern marker creation and fabric cutting. By integrating the system with the processes of garment sewing test of fit and final adjustment mass customization can be realized in the apparel industry. For the manufacturers the efficiency of the supply chain can be improved by reducing human efforts costs and production time. For the customers better fittings with faster delivery stimulate the desire of purchase and enhance their satisfaction. This paper illustrates that why Fashion CAD study is important for garment industry in Bangladesh.

  4. Inundation Analysis of Reservoir Flood Based on Computer Aided Design (CAD and Digital Elevation Model (DEM

    Directory of Open Access Journals (Sweden)

    Jiqing Li

    2018-04-01

    Full Text Available GIS (Geographic Information System can be used to combine multiple hydrologic data and geographic data for FIA (Flood Impact Assessment. For a developing country like China, a lot of geographic data is in the CAD (Computer Aided Design format. The commonly used method for converting CAD into DEM may result in data loss. This paper introduces a solution for the conversion between CAD data and DEM data. The method has been applied to the FIA based on the topographic map of CAD in Hanjiang River. When compared with the other method, the new method solves the data loss problem. Besides, the paper use GIS to simulate the inundation range, area, and the depth distribution of flood backwater. Based on the analysis, the author concludes: (1 the differences of the inundation areas between the flood of HQ100 and the flood of HQ50 are small. (2 The inundation depth shows a decreasing trend along the upstream of the river. (3 The inundation area less than 4 m in flood of HQ50 is larger than that in flood of HQ100, the result is opposite when the inundation depth is greater than 4 m. (4 The flood loss is 392.32 million RMB for flood of HQ50 and 610.02 million RMB for flood of HQ100. The method can be applied to FIA.

  5. An Analysis of Computer Aided Design (CAD) Packages Used at MSFC for the Recent Initiative to Integrate Engineering Activities

    Science.gov (United States)

    Smith, Leigh M.; Parker, Nelson C. (Technical Monitor)

    2002-01-01

    This paper analyzes the use of Computer Aided Design (CAD) packages at NASA's Marshall Space Flight Center (MSFC). It examines the effectiveness of recent efforts to standardize CAD practices across MSFC engineering activities. An assessment of the roles played by management, designers, analysts, and manufacturers in this initiative will be explored. Finally, solutions are presented for better integration of CAD across MSFC in the future.

  6. Computer-aided detection of pulmonary nodules: influence of nodule characteristics on detection performance

    International Nuclear Information System (INIS)

    Marten, K.; Engelke, C.; Seyfarth, T.; Grillhoesl, A.; Obenauer, S.; Rummeny, E.J.

    2005-01-01

    AIM: To evaluate prospectively the influence of pulmonary nodule characteristics on detection performances of a computer-aided diagnosis (CAD) tool and experienced chest radiologists using multislice CT (MSCT). MATERIALS AND METHODS: MSCT scans of 20 consecutive patients were evaluated by a CAD system and two independent chest radiologists for presence of pulmonary nodules. Nodule size, position, margin, matrix characteristics, vascular and pleural attachments and reader confidence were recorded and data compared with an independent standard of reference. Statistical analysis for predictors influencing nodule detection or reader performance included chi-squared, retrograde stepwise conditional logistic regression with odds ratios and nodule detection proportion estimates (DPE), and ROC analysis. RESULTS: For 135 nodules, detection rates for CAD and readers were 76.3, 52.6 and 52.6%, respectively; false-positive rates were 0.55, 0.25 and 0.15 per examination, respectively. In consensus with CAD the reader detection rate increased to 93.3%, and the false-positive rate dropped to 0.1/scan. DPEs for nodules ≤5 mm were significantly higher for ICAD than for the readers (p<0.05). Absence of vascular attachment was the only significant predictor of nodule detection by CAD (p=0.0006-0.008). There were no predictors of nodule detection for reader consensus with CAD. In contrast, vascular attachment predicted nodule detection by the readers (p=0.0001-0.003). Reader sensitivity was higher for nodules with vascular attachment than for unattached nodules (sensitivities 0.768 and 0.369; 95% confidence intervals=0.651-0.861 and 0.253-0.498, respectively). CONCLUSION: CAD increases nodule detection rates, decreases false-positive rates and compensates for deficient reader performance in detection of smallest lesions and of nodules without vascular attachment

  7. Computer-aided detection system applied to full-field digital mammograms

    International Nuclear Information System (INIS)

    Vega Bolivar, Alfonso; Sanchez Gomez, Sonia; Merino, Paula; Alonso-Bartolome, Pilar; Ortega Garcia, Estrella; Munoz Cacho, Pedro; Hoffmeister, Jeffrey W.

    2010-01-01

    Background: Although mammography remains the mainstay for breast cancer screening, it is an imperfect examination with a sensitivity of 75-92% for breast cancer. Computer-aided detection (CAD) has been developed to improve mammographic detection of breast cancer. Purpose: To retrospectively estimate CAD sensitivity and false-positive rate with full-field digital mammograms (FFDMs). Material and Methods: CAD was used to evaluate 151 cases of ductal carcinoma in situ (DCIS) (n=48) and invasive breast cancer (n=103) detected with FFDM. Retrospectively, CAD sensitivity was estimated based on breast density, mammographic presentation, histopathology type, and lesion size. CAD false-positive rate was estimated with screening FFDMs from 200 women. Results: CAD detected 93% (141/151) of cancer cases: 97% (28/29) in fatty breasts, 94% (81/86) in breasts containing scattered fibroglandular densities, 90% (28/31) in heterogeneously dense breasts, and 80% (4/5) in extremely dense breasts. CAD detected 98% (54/55) of cancers manifesting as calcifications, 89% (74/83) as masses, and 100% (13/13) as mixed masses and calcifications. CAD detected 92% (73/79) of invasive ductal carcinomas, 89% (8/9) of invasive lobular carcinomas, 93% (14/15) of other invasive carcinomas, and 96% (46/48) of DCIS. CAD sensitivity for cancers 1-10 mm was 87% (47/54); 11-20 mm, 99% (70/71); 21-30 mm, 86% (12/14); and larger than 30 mm, 100% (12/12). The CAD false-positive rate was 2.5 marks per case. Conclusion: CAD with FFDM showed a high sensitivity in identifying cancers manifesting as calcifications or masses. CAD sensitivity was maintained in small lesions (1-20 mm) and invasive lobular carcinomas, which have lower mammographic sensitivity

  8. Computer-aided detection system applied to full-field digital mammograms

    Energy Technology Data Exchange (ETDEWEB)

    Vega Bolivar, Alfonso; Sanchez Gomez, Sonia; Merino, Paula; Alonso-Bartolome, Pilar; Ortega Garcia, Estrella (Dept. of Radiology, Univ. Marques of Valdecilla Hospital, Santander (Spain)), e-mail: avegab@telefonica.net; Munoz Cacho, Pedro (Dept. of Statistics, Univ. Marques of Valdecilla Hospital, Santander (Spain)); Hoffmeister, Jeffrey W. (iCAD, Inc., Nashua, NH (United States))

    2010-12-15

    Background: Although mammography remains the mainstay for breast cancer screening, it is an imperfect examination with a sensitivity of 75-92% for breast cancer. Computer-aided detection (CAD) has been developed to improve mammographic detection of breast cancer. Purpose: To retrospectively estimate CAD sensitivity and false-positive rate with full-field digital mammograms (FFDMs). Material and Methods: CAD was used to evaluate 151 cases of ductal carcinoma in situ (DCIS) (n=48) and invasive breast cancer (n=103) detected with FFDM. Retrospectively, CAD sensitivity was estimated based on breast density, mammographic presentation, histopathology type, and lesion size. CAD false-positive rate was estimated with screening FFDMs from 200 women. Results: CAD detected 93% (141/151) of cancer cases: 97% (28/29) in fatty breasts, 94% (81/86) in breasts containing scattered fibroglandular densities, 90% (28/31) in heterogeneously dense breasts, and 80% (4/5) in extremely dense breasts. CAD detected 98% (54/55) of cancers manifesting as calcifications, 89% (74/83) as masses, and 100% (13/13) as mixed masses and calcifications. CAD detected 92% (73/79) of invasive ductal carcinomas, 89% (8/9) of invasive lobular carcinomas, 93% (14/15) of other invasive carcinomas, and 96% (46/48) of DCIS. CAD sensitivity for cancers 1-10 mm was 87% (47/54); 11-20 mm, 99% (70/71); 21-30 mm, 86% (12/14); and larger than 30 mm, 100% (12/12). The CAD false-positive rate was 2.5 marks per case. Conclusion: CAD with FFDM showed a high sensitivity in identifying cancers manifesting as calcifications or masses. CAD sensitivity was maintained in small lesions (1-20 mm) and invasive lobular carcinomas, which have lower mammographic sensitivity

  9. Computer-aided detection system for chest radiography: reducing report turnaround times of examinations with abnormalities.

    Science.gov (United States)

    Kao, E-Fong; Liu, Gin-Chung; Lee, Lo-Yeh; Tsai, Huei-Yi; Jaw, Twei-Shiun

    2015-06-01

    The ability to give high priority to examinations with pathological findings could be very useful to radiologists with large work lists who wish to first evaluate the most critical studies. A computer-aided detection (CAD) system for identifying chest examinations with abnormalities has therefore been developed. To evaluate the effectiveness of a CAD system on report turnaround times of chest examinations with abnormalities. The CAD system was designed to automatically mark chest examinations with possible abnormalities in the work list of radiologists interpreting chest examinations. The system evaluation was performed in two phases: two radiologists interpreted the chest examinations without CAD in phase 1 and with CAD in phase 2. The time information recorded by the radiology information system was then used to calculate the turnaround times. All chest examinations were reviewed by two other radiologists and were divided into normal and abnormal groups. The turnaround times for the examinations with pathological findings with and without the CAD system assistance were compared. The sensitivity and specificity of the CAD for chest abnormalities were 0.790 and 0.697, respectively, and use of the CAD system decreased the turnaround time for chest examinations with abnormalities by 44%. The turnaround times required for radiologists to identify chest examinations with abnormalities could be reduced by using the CAD system. This system could be useful for radiologists with large work lists who wish to first evaluate the most critical studies. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  10. Computer-aided detection in CT colonography: initial clinical experience using a prototype system

    International Nuclear Information System (INIS)

    Graser, A.; Geisbuesch, S.; Reiser, M.F.; Becker, C.R.; Kolligs, F.T.; Schaefer, C.; Mang, T.

    2007-01-01

    Computer-aided detection (CAD) algorithms help to detect colonic polyps at CT colonography (CTC). The purpose of this study was to evaluate the accuracy of CAD versus an expert reader in CTC. One hundred forty individuals (67 men, 73 women; mean age, 59 years) underwent screening 64-MDCT colonography after full cathartic bowel cleansing without fecal tagging. One expert reader interpreted supine and prone scans using a 3D workstation with integrated CAD used as ''second reader.'' The system's sensitivity for the detection of polyps, the number of false-positive findings, and its running time were evaluated. Polyps were classified as small (≤5 mm), medium (6-9 mm), and large (≥10 mm). A total of 118 polyps (small, 85; medium, 19; large, 14) were found in 56 patients. CAD detected 72 polyps (61%) with an average of 2.2 false-positives. Sensitivity was 51% (43/85) for small, 90% (17/19) for medium, and 86% (12/14) for large polyps. For all polyps, per-patient sensitivity was 89% (50/56) for the radiologist and 73% (41/56) for CAD. For large and medium polyps, per-patient sensitivity was 100% for the radiologist, and 96% for CAD. In conclusion, CAD shows high sensitivity in the detection of clinically significant polyps with acceptable false-positive rates. (orig.)

  11. Computer-aided design and computer-aided modeling (CAD/CAM) generated surgical splints, cutting guides and custom-made implants: Which indications in orthognathic surgery?

    Science.gov (United States)

    Scolozzi, P

    2015-12-01

    The purpose of the present report was to describe our indications, results and complications of computer-aided design and computer-aided modeling CAD/CAM surgical splints, cutting guides and custom-made implants in orthognathic surgery. We analyzed the clinical and radiological data of ten consecutive patients with dentofacial deformities treated using a CAD/CAM technique. Four patients had surgical splints and cutting guides for correction of maxillomandibular asymmetries, three had surgical cutting guides and customized internal distractors for correction of severe maxillary deficiencies and three had custom-made implants for additional chin contouring and/or mandibular defects following bimaxillary osteotomies and sliding genioplasty. We recorded age, gender, dentofacial deformity, surgical procedure and intra- and postoperative complications. All of the patients had stable cosmetic results with a high rate of patient satisfaction at the 1-year follow-up examination. No intra- and/or postoperative complications were encountered during any of the different steps of the procedure. This study demonstrated that the application of CAD/CAM patient-specific surgical splints, cutting guides and custom-made implants in orthognathic surgery allows for a successful outcome in the ten patients presented in this series. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Computer-aided detection and automated CT volumetry of pulmonary nodules

    International Nuclear Information System (INIS)

    Marten, Katharina; Engelke, Christoph

    2007-01-01

    With use of multislice computed tomography (MSCT), small pulmonary nodules are being detected in vast numbers, constituting the majority of all noncalcified lung nodules. Although the prevalence of lung cancers among such lesions in lung cancer screening populations is low, their isolation may contribute to increased patient survival. Computer-aided diagnosis (CAD) has emerged as a diverse set of diagnostic tools to handle the large number of images in MSCT datasets and most importantly, includes automated detection and volumetry of pulmonary nodules. Current CAD systems can significantly enhance experienced radiologists' performance and outweigh human limitations in identifying small lesions and manually measuring their diameters, augment observer consistency in the interpretation of such examinations and may thus help to detect significantly higher rates of early malignomas and give more precise estimates on chemotherapy response than can radiologists alone. In this review, we give an overview of current CAD in lung nodule detection and volumetry and discuss their relative merits and limitations. (orig.)

  13. Computer-aided detection in computed tomography colonography. Current status and problems with detection of early colorectal cancer

    International Nuclear Information System (INIS)

    Morimoto, Tsuyoshi; Nakijima, Yasuo; Iinuma, Gen; Arai, Yasuaki; Shiraishi, Junji; Moriyama, Noriyuki; Beddoe, G.

    2008-01-01

    The aim of this study was to evaluate the usefulness of computer-aided detection (CAD) in diagnosing early colorectal cancer using computed tomography colonography (CTC). A total of 30 CTC data sets for 30 early colorectal cancers in 30 patients were retrospectively reviewed by three radiologists. After primary evaluation, a second reading was performed using CAD findings. The readers evaluated each colorectal segment for the presence or absence of colorectal cancer using five confidence rating levels. To compare the assessment results, the sensitivity and specificity with and without CAD were calculated on the basis of the confidence rating, and differences in these variables were analyzed by receiver operating characteristic (ROC) analysis. The average sensitivities for the detection without and with CAD for the three readers were 81.6% and 75.6%, respectively. Among the three readers, only one reader improved sensitivity with CAD compared to that without. CAD decreased specificity in all three readers. CAD detected 100% of protruding lesions but only 69.2% of flat lesions. On ROC analysis, the diagnostic performance of all three readers was decreased by use of CAD. Currently available CAD with CTC does not improve diagnostic performance for detecting early colorectal cancer. An improved CAD algorithm is required for detecting fiat lesions and reducing the false-positive rate. (author)

  14. Computer-aided detection of brain metastasis on 3D MR imaging: Observer performance study.

    Directory of Open Access Journals (Sweden)

    Leonard Sunwoo

    Full Text Available To assess the effect of computer-aided detection (CAD of brain metastasis (BM on radiologists' diagnostic performance in interpreting three-dimensional brain magnetic resonance (MR imaging using follow-up imaging and consensus as the reference standard.The institutional review board approved this retrospective study. The study cohort consisted of 110 consecutive patients with BM and 30 patients without BM. The training data set included MR images of 80 patients with 450 BM nodules. The test set included MR images of 30 patients with 134 BM nodules and 30 patients without BM. We developed a CAD system for BM detection using template-matching and K-means clustering algorithms for candidate detection and an artificial neural network for false-positive reduction. Four reviewers (two neuroradiologists and two radiology residents interpreted the test set images before and after the use of CAD in a sequential manner. The sensitivity, false positive (FP per case, and reading time were analyzed. A jackknife free-response receiver operating characteristic (JAFROC method was used to determine the improvement in the diagnostic accuracy.The sensitivity of CAD was 87.3% with an FP per case of 302.4. CAD significantly improved the diagnostic performance of the four reviewers with a figure-of-merit (FOM of 0.874 (without CAD vs. 0.898 (with CAD according to JAFROC analysis (p < 0.01. Statistically significant improvement was noted only for less-experienced reviewers (FOM without vs. with CAD, 0.834 vs. 0.877, p < 0.01. The additional time required to review the CAD results was approximately 72 sec (40% of the total review time.CAD as a second reader helps radiologists improve their diagnostic performance in the detection of BM on MR imaging, particularly for less-experienced reviewers.

  15. Computer-aided detection of brain metastasis on 3D MR imaging: Observer performance study.

    Science.gov (United States)

    Sunwoo, Leonard; Kim, Young Jae; Choi, Seung Hong; Kim, Kwang-Gi; Kang, Ji Hee; Kang, Yeonah; Bae, Yun Jung; Yoo, Roh-Eul; Kim, Jihang; Lee, Kyong Joon; Lee, Seung Hyun; Choi, Byung Se; Jung, Cheolkyu; Sohn, Chul-Ho; Kim, Jae Hyoung

    2017-01-01

    To assess the effect of computer-aided detection (CAD) of brain metastasis (BM) on radiologists' diagnostic performance in interpreting three-dimensional brain magnetic resonance (MR) imaging using follow-up imaging and consensus as the reference standard. The institutional review board approved this retrospective study. The study cohort consisted of 110 consecutive patients with BM and 30 patients without BM. The training data set included MR images of 80 patients with 450 BM nodules. The test set included MR images of 30 patients with 134 BM nodules and 30 patients without BM. We developed a CAD system for BM detection using template-matching and K-means clustering algorithms for candidate detection and an artificial neural network for false-positive reduction. Four reviewers (two neuroradiologists and two radiology residents) interpreted the test set images before and after the use of CAD in a sequential manner. The sensitivity, false positive (FP) per case, and reading time were analyzed. A jackknife free-response receiver operating characteristic (JAFROC) method was used to determine the improvement in the diagnostic accuracy. The sensitivity of CAD was 87.3% with an FP per case of 302.4. CAD significantly improved the diagnostic performance of the four reviewers with a figure-of-merit (FOM) of 0.874 (without CAD) vs. 0.898 (with CAD) according to JAFROC analysis (p reviewers (FOM without vs. with CAD, 0.834 vs. 0.877, p review the CAD results was approximately 72 sec (40% of the total review time). CAD as a second reader helps radiologists improve their diagnostic performance in the detection of BM on MR imaging, particularly for less-experienced reviewers.

  16. Computer-Aided Detection of Malignant Lung Nodules on Chest Radiographs: Effect on Observers' Performance

    International Nuclear Information System (INIS)

    Lee, Kyung Hee; Goo, Jin Mo; Park, Chang Min; Lee, Hyun Ju; Jin, Kwang Nam

    2012-01-01

    To evaluate the effect of computer-aided detection (CAD) system on observer performance in the detection of malignant lung nodules on chest radiograph. Two hundred chest radiographs (100 normal and 100 abnormal with malignant solitary lung nodules) were evaluated. With CT and histological confirmation serving as a reference, the mean nodule size was 15.4 mm (range, 7-20 mm). Five chest radiologists and five radiology residents independently interpreted both the original radiographs and CAD output images using the sequential testing method. The performances of the observers for the detection of malignant nodules with and without CAD were compared using the jackknife free-response receiver operating characteristic analysis. Fifty-nine nodules were detected by the CAD system with a false positive rate of 1.9 nodules per case. The detection of malignant lung nodules significantly increased from 0.90 to 0.92 for a group of observers, excluding one first-year resident (p = 0.04). When lowering the confidence score was not allowed, the average figure of merit also increased from 0.90 to 0.91 (p = 0.04) for all observers after a CAD review. On average, the sensitivities with and without CAD were 87% and 84%, respectively; the false positive rates per case with and without CAD were 0.19 and 0.17, respectively. The number of additional malignancies detected following true positive CAD marks ranged from zero to seven for the various observers. The CAD system may help improve observer performance in detecting malignant lung nodules on chest radiographs and contribute to a decrease in missed lung cancer.

  17. Computer-aided detection of breast carcinoma in standard mammographic projections with digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Destounis, Stamatia [Elizabeth Wende Breast Care, LLC, Rochester, NY (United States); University of Rochester, School of Medicine and Dentistry, Rochester, NY (United States); Hanson, Sarah; Morgan, Renee; Murphy, Philip; Somerville, Patricia; Seifert, Posy; Andolina, Valerie; Arieno, Andrea; Skolny, Melissa; Logan-Young, Wende [Elizabeth Wende Breast Care, LLC, Rochester, NY (United States)

    2009-06-15

    A retrospective evaluation of the ability of computer-aided detection (CAD) ability to identify breast carcinoma in standard mammographic projections. Forty-five biopsy proven lesions in 44 patients imaged digitally with CAD applied at examination were reviewed. Forty-four screening BIRADS {sup registered} category 1 digital mammography examinations were randomly identified to serve as a comparative normal/control population. Data included patient age; BIRADS {sup registered} breast density; lesion type, size, and visibility; number, type, and location of CAD marks per image; CAD ability to mark lesions; needle core and surgical pathologic correlation. The CAD lesion/case sensitivity of 87% (n=39), image sensitivity of 69% (n=31) for mediolateral oblique view and 78% (n=35) for the craniocaudal view was found. The average false positive rate in 44 normal screening cases was 2.0 (range 1-8). The 2.0 figure is based on 88 reported false positive CAD marks in 44 normal screening exams: 98% (n=44) lesions proceeded to excision; initial pathology upgraded at surgical excision from in situ to invasive disease in 24% (n=9) lesions. CAD demonstrated potential to detect mammographically visible cancers in standard projections for all lesion types. (orig.)

  18. A Robust and Fast System for CTC Computer-Aided Detection of Colorectal Lesions

    Directory of Open Access Journals (Sweden)

    Gareth Beddoe

    2010-01-01

    Full Text Available We present a complete, end-to-end computer-aided detection (CAD system for identifying lesions in the colon, imaged with computed tomography (CT. This system includes facilities for colon segmentation, candidate generation, feature analysis, and classification. The algorithms have been designed to offer robust performance to variation in image data and patient preparation. By utilizing efficient 2D and 3D processing, software optimizations, multi-threading, feature selection, and an optimized cascade classifier, the CAD system quickly determines a set of detection marks. The colon CAD system has been validated on the largest set of data to date, and demonstrates excellent performance, in terms of its high sensitivity, low false positive rate, and computational efficiency.

  19. Reproducibility of Computer-Aided Detection Marks in Digital Mammography

    International Nuclear Information System (INIS)

    Kim, Seung Ja; Moon, Woo Kyung; Cho, Nariya; Kim, Sun Mi; Im, Jung Gi; Cha, Joo Hee

    2007-01-01

    To evaluate the performance and reproducibility of a computeraided detection (CAD) system in mediolateral oblique (MLO) digital mammograms taken serially, without release of breast compression. A CAD system was applied preoperatively to the fulfilled digital mammograms of two MLO views taken without release of breast compression in 82 patients (age range: 33 83 years; mean age: 49 years) with previously diagnosed breast cancers. The total number of visible lesion components in 82 patients was 101: 66 masses and 35 microcalcifications. We analyzed the sensitivity and reproducibility of the CAD marks. The sensitivity of the CAD system for first MLO views was 71% (47/66) for masses and 80% (28/35) for microcalcifications. The sensitivity of the CAD system for second MLO views was 68% (45/66) for masses and 17% (6/35) for microcalcifications. In 84 ipsilateral serial MLO image sets (two patients had bilateral cancers), identical images, regardless of the existence of CAD marks, were obtained for 35% (29/84) and identical images with CAD marks were obtained for 29% (23/78). Identical images, regardless of the existence of CAD marks, for contralateral MLO images were 65% (52/80) and identical images with CAD marks were obtained for 28% (11/39). The reproducibility of CAD marks for the true positive masses in serial MLO views was 84% (42/50) and that for the true positive microcalcifications was 0% (0/34). The CAD system in digital mammograms showed a high sensitivity for detecting masses and microcalcifications. However, reproducibility of microcalcification marks was very low in MLO views taken serially without release of breast compression. Minute positional change and patient movement can alter the images and result in a significant effect on the algorithm utilized by the CAD for detecting microcalcifications

  20. CT colonography: computer-aided detection of morphologically flat T1 colonic carcinoma

    International Nuclear Information System (INIS)

    Taylor, Stuart A.; Iinuma, Gen; Saito, Yutaka; Zhang, Jie; Halligan, Steve

    2008-01-01

    The purpose was to evaluate the ability of computer-aided detection (CAD) software to detect morphologically flat early colonic carcinoma using CT colonography (CTC). Twenty-four stage T1 colonic carcinomas endoscopically classified as flat (width over twice height) were accrued from patients undergoing staging CTC. Tumor location was annotated by three experienced radiologists in consensus aided by the endosocpic report. CAD software was then applied at three settings of sphericity (0, 0.75, and 1). Computer prompts were categorized as either true positive (overlapping tumour boundary) or false positive. True positives were subclassified as focal or non focal. The 24 cancers were endoscopically classified as type IIa (n=11) and type IIa+IIc (n=13). Mean size (range) was 27 mm (7-70 mm). CAD detected 20 (83.3%), 17 (70.8%), and 13 (54.1%) of the 24 cancers at filter settings of 0, 0.75, and 1, respectively with 3, 4, and 8 missed cancers of type IIa, respectively. The mean total number of false-positive CAD marks per patient at each filter setting was 36.5, 21.1, and 9.5, respectively, excluding polyps. At all settings, >96.1% of CAD true positives were classified as focal. CAD may be effective for the detection of morphologically flat cancer, although minimally raised laterally spreading tumors remain problematic. (orig.)

  1. Computer-aided detection as a decision assistant in chest radiography

    Science.gov (United States)

    Samulski, Maurice R. M.; Snoeren, Peter R.; Platel, Bram; van Ginneken, Bram; Hogeweg, Laurens; Schaefer-Prokop, Cornelia; Karssemeijer, Nico

    2011-03-01

    Background. Contrary to what may be expected, finding abnormalities in complex images like pulmonary nodules in chest radiographs is not dominated by time-consuming search strategies but by an almost immediate global interpretation. This was already known in the nineteen-seventies from experiments with briefly flashed chest radiographs. Later on, experiments with eye-trackers showed that abnormalities attracted the attention quite fast but often without further reader actions. Prolonging one's search seldom leads to newly found abnormalities and may even increase the chance of errors. The problem of reading chest radiographs is therefore not dominated by finding the abnormalities, but by interpreting them. Hypothesis. This suggests that readers could benefit from computer-aided detection (CAD) systems not so much by their ability to prompt potential abnormalities, but more from their ability to 'interpret' the potential abnormalities. In this paper, this hypothesis was investigated by an observer experiment. Experiment. In one condition, the traditional CAD condition, the most suspicious CAD locations were shown to the subjects, without telling them the levels of suspiciousness according to CAD. In the other condition, interactive CAD condition, levels of suspiciousness were given, but only when readers requested them at specified locations. These two conditions focus on decreasing search errors and decision errors, respectively. Results of reading without CAD were also recorded. Six subjects, all non-radiologists, read 223 chest radiographs in both conditions. CAD results were obtained from the OnGuard 5.0 system developed by Riverain Medical (Miamisburg, Ohio). Results. The observer data were analyzed by Location Response Operating Characteristic analysis (LROC). It was found that: 1) With the aid of CAD, the performance is significantly better than without CAD; 2) The performance with interactive CAD is significantly better than with traditional CAD at low false

  2. Effect of radiation dose reduction and iterative reconstruction on computer-aided detection of pulmonary nodules : Intra-individual comparison

    NARCIS (Netherlands)

    Den Harder, Annemarie M.; Willemink, Martin J.; Van Hamersvelt, Robbert W.; Vonken, Evert-Jan P A; Milles, Julien; Schilham, Arnold M R; Lammers, Jan Willem; De Jong, Pim A.; Leiner, Tim; Budde, Ricardo P J

    2016-01-01

    Objective To evaluate the effect of radiation dose reduction and iterative reconstruction (IR) on the performance of computer-aided detection (CAD) for pulmonary nodules. Methods In this prospective study twenty-five patients were included who were scanned for pulmonary nodule follow-up. Image

  3. Effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low dose CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Sun [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Kim, Se Hyung, E-mail: shkim7071@gmail.com [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Im, Jong Pil; Kim, Sang Gyun [Department of Internal Medicine, Seoul National University Hospital (Korea, Republic of); Shin, Cheong-il; Han, Joon Koo; Choi, Byung Ihn [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of)

    2015-04-15

    Highlights: •We assessed the effect of reconstruction algorithms on CAD in ultra-low dose CTC. •30 patients underwent ultra-low dose CTC using 120 and 100 kVp with 10 mAs. •CT was reconstructed with FBP, ASiR and Veo and then, we applied a CAD system. •Per-polyp sensitivity of CAD in ULD CT can be improved with the IR algorithms. •Despite of an increase in the number of FPs with IR, it was still acceptable. -- Abstract: Purpose: To assess the effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low-dose CT colonography (ULD CTC). Materials and methods: IRB approval and informed consents were obtained. Thirty prospectively enrolled patients underwent non-contrast CTC at 120 kVp/10 mAs in supine and 100 kVp/10 mAs in prone positions, followed by same-day colonoscopy. Images were reconstructed with filtered back projection (FBP), 80% adaptive statistical iterative reconstruction (ASIR80), and model-based iterative reconstruction (MBIR). A commercial CAD system was applied and per-polyp sensitivities and numbers of false-positives (FPs) were compared among algorithms. Results: Mean effective radiation dose of CTC was 1.02 mSv. Of 101 polyps detected and removed by colonoscopy, 61 polyps were detected on supine and on prone CTC datasets on consensus unblinded review, resulting in 122 visible polyps (32 polyps <6 mm, 52 6–9.9 mm, and 38 ≥ 10 mm). Per-polyp sensitivity of CAD for all polyps was highest with MBIR (56/122, 45.9%), followed by ASIR80 (54/122, 44.3%) and FBP (43/122, 35.2%), with significant differences between FBP and IR algorithms (P < 0.017). Per-polyp sensitivity for polyps ≥ 10 mm was also higher with MBIR (25/38, 65.8%) and ASIR80 (24/38, 63.2%) than with FBP (20/38, 58.8%), albeit without statistical significance (P > 0.017). Mean number of FPs was significantly different among algorithms (FBP, 1.4; ASIR, 2.1; MBIR, 2.4) (P = 0.011). Conclusion: Although the performance of stand-alone CAD

  4. Effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low dose CT colonography

    International Nuclear Information System (INIS)

    Lee, Eun Sun; Kim, Se Hyung; Im, Jong Pil; Kim, Sang Gyun; Shin, Cheong-il; Han, Joon Koo; Choi, Byung Ihn

    2015-01-01

    Highlights: •We assessed the effect of reconstruction algorithms on CAD in ultra-low dose CTC. •30 patients underwent ultra-low dose CTC using 120 and 100 kVp with 10 mAs. •CT was reconstructed with FBP, ASiR and Veo and then, we applied a CAD system. •Per-polyp sensitivity of CAD in ULD CT can be improved with the IR algorithms. •Despite of an increase in the number of FPs with IR, it was still acceptable. -- Abstract: Purpose: To assess the effect of different reconstruction algorithms on computer-aided diagnosis (CAD) performance in ultra-low-dose CT colonography (ULD CTC). Materials and methods: IRB approval and informed consents were obtained. Thirty prospectively enrolled patients underwent non-contrast CTC at 120 kVp/10 mAs in supine and 100 kVp/10 mAs in prone positions, followed by same-day colonoscopy. Images were reconstructed with filtered back projection (FBP), 80% adaptive statistical iterative reconstruction (ASIR80), and model-based iterative reconstruction (MBIR). A commercial CAD system was applied and per-polyp sensitivities and numbers of false-positives (FPs) were compared among algorithms. Results: Mean effective radiation dose of CTC was 1.02 mSv. Of 101 polyps detected and removed by colonoscopy, 61 polyps were detected on supine and on prone CTC datasets on consensus unblinded review, resulting in 122 visible polyps (32 polyps <6 mm, 52 6–9.9 mm, and 38 ≥ 10 mm). Per-polyp sensitivity of CAD for all polyps was highest with MBIR (56/122, 45.9%), followed by ASIR80 (54/122, 44.3%) and FBP (43/122, 35.2%), with significant differences between FBP and IR algorithms (P < 0.017). Per-polyp sensitivity for polyps ≥ 10 mm was also higher with MBIR (25/38, 65.8%) and ASIR80 (24/38, 63.2%) than with FBP (20/38, 58.8%), albeit without statistical significance (P > 0.017). Mean number of FPs was significantly different among algorithms (FBP, 1.4; ASIR, 2.1; MBIR, 2.4) (P = 0.011). Conclusion: Although the performance of stand-alone CAD

  5. Potential contribution of multiplanar reconstruction (MPR) to computer-aided detection of lung nodules on MDCT

    International Nuclear Information System (INIS)

    Matsumoto, Sumiaki; Ohno, Yoshiharu; Yamagata, Hitoshi; Nogami, Munenobu; Kono, Atsushi; Sugimura, Kazuro

    2012-01-01

    Purpose: To evaluate potential benefits of using multiplanar reconstruction (MPR) in computer-aided detection (CAD) of lung nodules on multidetector computed tomography (MDCT). Materials and methods: MDCT datasets of 60 patients with suspected lung nodules were retrospectively collected. Using “second-read” CAD, two radiologists (Readers 1 and 2) independently interpreted these datasets for the detection of non-calcified nodules (≥4 mm) with concomitant confidence rating. They did this task twice, first without MPR (using only axial images), and then 4 weeks later with MPR (using also coronal and sagittal MPR images), where the total reading time per dataset, including the time taken to assess the detection results of CAD software (CAD assessment time), was recorded. The total reading time and CAD assessment time without MPR and those with MPR were statistically compared for each reader. The radiologists’ performance for detecting nodules without MPR and the performance with MPR were compared using jackknife free-response receiver operating characteristic (JAFROC) analysis. Results: Compared to the CAD assessment time without MPR (mean, 69 s and 57 s for Readers 1 and 2), the CAD assessment time with MPR (mean, 46 s and 45 s for Readers 1 and 2) was significantly reduced (P < 0.001). For Reader 1, the total reading time was also significantly shorter in the case with MPR. There was no significant difference between the detection performances without MPR and with MPR. Conclusion: The use of MPR has the potential to improve the workflow in CAD of lung nodules on MDCT.

  6. Computer-aided detection of breast carcinoma in standard mammographic projections with digital mammography

    International Nuclear Information System (INIS)

    Destounis, S.; Hanson, S.

    2007-01-01

    This study was conducted to retrospectively evaluate a computer-aided detection system's ability to detect breast carcinoma in multiple standard mammographic projections. Forty-five lesions in 44 patients imaged with digital mammography (Selenia registered , Hologic, Bedford, MA; Senographe registered , GE, Milwaukee, WI) and had computer-aided detection (CAD, Image-checker registered V 8.3.15, Hologic/R2, Santa Clara, CA) applied at the time of examination were identified for review; all were subsequently recommended to biopsy where cancer was revealed. These lesions were determined by the study Radiologist to be visible in both standard mammographic images (mediolateral oblique, MLO; craniocaudal, CC). For each patient, case data included patient age, tissue density, lesion type, BIRADS registered assessment, lesion size, lesion visibility-visible on MLO and/or CC view, ability of CAD to correctly mark the cancerous lesion, number of CAD marks per image, needle core biopsy results and surgical pathologic correlation. For this study cohort. CAD lesion/case sensitivity of 87% (n = 39) was found and image sensitivity was found to be 69% (n = 31) for MLO view and 78% (n = 35) for the CC view. For the study cohort, cases presented with a median of four marks per cases (range 0-13). Eighty-four percent (n = 38) of lesions proceeded to excision; initial needle biopsy pathology was upgraded at surgical excision from in situ disease to invasive for 24% (n = 9) lesions. CAD has demonstrated the potential to detect mammographically visible cancers in multiple standard mammographic projections in all categories of lesions in this study cohort. (orig.)

  7. The effect of computer-aided detection markers on visual search and reader performance during concurrent reading of CT colonography

    International Nuclear Information System (INIS)

    Helbren, Emma; Taylor, Stuart A.; Fanshawe, Thomas R.; Mallett, Susan; Phillips, Peter; Boone, Darren; Gale, Alastair; Altman, Douglas G.; Manning, David; Halligan, Steve

    2015-01-01

    We aimed to identify the effect of computer-aided detection (CAD) on visual search and performance in CT Colonography (CTC) of inexperienced and experienced readers. Fifteen endoluminal CTC examinations were recorded, each with one polyp, and two videos were generated, one with and one without a CAD mark. Forty-two readers (17 experienced, 25 inexperienced) interpreted the videos during infrared visual search recording. CAD markers and polyps were treated as regions of interest in data processing. This multi-reader, multi-case study was analysed using multilevel modelling. CAD drew readers' attention to polyps faster, accelerating identification times: median 'time to first pursuit' was 0.48 s (IQR 0.27 to 0.87 s) with CAD, versus 0.58 s (IQR 0.35 to 1.06 s) without. For inexperienced readers, CAD also held visual attention for longer. All visual search metrics used to assess visual gaze behaviour demonstrated statistically significant differences when ''with'' and ''without'' CAD were compared. A significant increase in the number of correct polyp identifications across all readers was seen with CAD (74 % without CAD, 87 % with CAD; p < 0.001). CAD significantly alters visual search and polyp identification in readers viewing three-dimensional endoluminal CTC. For polyp and CAD marker pursuit times, CAD generally exerted a larger effect on inexperienced readers. (orig.)

  8. The effect of computer-aided detection markers on visual search and reader performance during concurrent reading of CT colonography

    Energy Technology Data Exchange (ETDEWEB)

    Helbren, Emma; Taylor, Stuart A. [University College London, Centre for Medical Imaging, London (United Kingdom); Fanshawe, Thomas R.; Mallett, Susan [University of Oxford, Nuffield Department of Primary Care Health Sciences, Oxford (United Kingdom); Phillips, Peter [University of Cumbria, Health and Medical Sciences Group, Lancaster (United Kingdom); Boone, Darren [Colchester Hospital University NHS Foundation Trust and Anglia University, Colchester (United Kingdom); Gale, Alastair [Loughborough University, Applied Vision Research Centre, Loughborough (United Kingdom); Altman, Douglas G. [University of Oxford, Centre for Statistics in Medicine, Oxford (United Kingdom); Manning, David [Lancaster University, Lancaster Medical School, Faculty of Health and Medicine, Lancaster (United Kingdom); Halligan, Steve [University College London, Centre for Medical Imaging, London (United Kingdom); University College Hospital, Gastrointestinal Radiology, University College London, Centre for Medical Imaging, Podium Level 2, London, NW1 2BU (United Kingdom)

    2015-06-01

    We aimed to identify the effect of computer-aided detection (CAD) on visual search and performance in CT Colonography (CTC) of inexperienced and experienced readers. Fifteen endoluminal CTC examinations were recorded, each with one polyp, and two videos were generated, one with and one without a CAD mark. Forty-two readers (17 experienced, 25 inexperienced) interpreted the videos during infrared visual search recording. CAD markers and polyps were treated as regions of interest in data processing. This multi-reader, multi-case study was analysed using multilevel modelling. CAD drew readers' attention to polyps faster, accelerating identification times: median 'time to first pursuit' was 0.48 s (IQR 0.27 to 0.87 s) with CAD, versus 0.58 s (IQR 0.35 to 1.06 s) without. For inexperienced readers, CAD also held visual attention for longer. All visual search metrics used to assess visual gaze behaviour demonstrated statistically significant differences when ''with'' and ''without'' CAD were compared. A significant increase in the number of correct polyp identifications across all readers was seen with CAD (74 % without CAD, 87 % with CAD; p < 0.001). CAD significantly alters visual search and polyp identification in readers viewing three-dimensional endoluminal CTC. For polyp and CAD marker pursuit times, CAD generally exerted a larger effect on inexperienced readers. (orig.)

  9. Computer-aided detection of early interstitial lung diseases using low-dose CT images

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Cheol; Kim, Soo Hyung [School of Electronics and Computer Engineering, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Tan, Jun; Wang Xingwei; Lederman, Dror; Leader, Joseph K; Zheng Bin, E-mail: zhengb@upmc.edu [Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15213 (United States)

    2011-02-21

    This study aims to develop a new computer-aided detection (CAD) scheme to detect early interstitial lung disease (ILD) using low-dose computed tomography (CT) examinations. The CAD scheme classifies each pixel depicted on the segmented lung areas into positive or negative groups for ILD using a mesh-grid-based region growth method and a multi-feature-based artificial neural network (ANN). A genetic algorithm was applied to select optimal image features and the ANN structure. In testing each CT examination, only pixels selected by the mesh-grid region growth method were analyzed and classified by the ANN to improve computational efficiency. All unselected pixels were classified as negative for ILD. After classifying all pixels into the positive and negative groups, CAD computed a detection score based on the ratio of the number of positive pixels to all pixels in the segmented lung areas, which indicates the likelihood of the test case being positive for ILD. When applying to an independent testing dataset of 15 positive and 15 negative cases, the CAD scheme yielded the area under receiver operating characteristic curve (AUC = 0.884 {+-} 0.064) and 80.0% sensitivity at 85.7% specificity. The results demonstrated the feasibility of applying the CAD scheme to automatically detect early ILD using low-dose CT examinations.

  10. Effect of Computer-Aided Detection on Mammographic Performance: Experimental Study on Readers with Different Levels of Experience

    International Nuclear Information System (INIS)

    Hukkinen, K.; Vehmas, T.; Pamilo, M.; Kivisaari, L.

    2006-01-01

    Purpose: To evaluate the effect of computer-aided detection (CAD) on the reader's performance. Material and Methods: Four screening radiologists, two novice radiologists, and two residents with no prior experience in CAD read films of 200 women without and with CAD. The films, including 16 screen-detected cancers and 35 cancers 'missed' on prior screening, were divided into two rollers: A (free time schedule) and B (prompted time schedule). Reading times were noted. Individual readings without and with CAD were compared, sensitivities and specificities were calculated. Results: The sensitivity of CAD was 70.6% and specificity 15.8%. In 408 cancer readings, the screeners found 10 and other readers 7 new cancers with the aid of CAD. The screeners changed their opinion four times and others six times from true positive to false negative when CAD was negative. CAD output produced 12 versus 13 new false-positive findings respectively after 2352 readings. CAD did not significantly affect the reader's sensitivities/specificities regardless of the time limit (P = not significant). The use of CAD increased mean time for roller reading from 56 to 63 min (P = 0.053). Conclusion: Screening radiologists benefited slightly more from CAD than other readers did, but no statistical significant difference was found in personal readings without and with CAD

  11. [Evaluation of production and clinical working time of computer-aided design/computer-aided manufacturing (CAD/CAM) custom trays for complete denture].

    Science.gov (United States)

    Wei, L; Chen, H; Zhou, Y S; Sun, Y C; Pan, S X

    2017-02-18

    To compare the technician fabrication time and clinical working time of custom trays fabricated using two different methods, the three-dimensional printing custom trays and the conventional custom trays, and to prove the feasibility of the computer-aided design/computer-aided manufacturing (CAD/CAM) custom trays in clinical use from the perspective of clinical time cost. Twenty edentulous patients were recruited into this study, which was prospective, single blind, randomized self-control clinical trials. Two custom trays were fabricated for each participant. One of the custom trays was fabricated using functional suitable denture (FSD) system through CAD/CAM process, and the other was manually fabricated using conventional methods. Then the final impressions were taken using both the custom trays, followed by utilizing the final impression to fabricate complete dentures respectively. The technician production time of the custom trays and the clinical working time of taking the final impression was recorded. The average time spent on fabricating the three-dimensional printing custom trays using FSD system and fabricating the conventional custom trays manually were (28.6±2.9) min and (31.1±5.7) min, respectively. The average time spent on making the final impression with the three-dimensional printing custom trays using FSD system and the conventional custom trays fabricated manually were (23.4±11.5) min and (25.4±13.0) min, respectively. There was significant difference in the technician fabrication time and the clinical working time between the three-dimensional printing custom trays using FSD system and the conventional custom trays fabricated manually (Pmanufacture custom trays by three-dimensional printing method, there is no need to pour preliminary cast after taking the primary impression, therefore, it can save the impression material and model material. As to completing denture restoration, manufacturing custom trays using FSD system is worth being

  12. Computer-aided detection of small pulmonary nodules in multidetector spiral computed tomography (MSCT) in children

    International Nuclear Information System (INIS)

    Honnef, D.; Behrendt, F.F.; Hohl, C.; Mahnken, A.H.; Guenther, R.W.; Das, M.; Mertens, R.; Stanzel, S.

    2008-01-01

    Purpose: Retrospective evaluation of computer-aided detection software (CAD) for automated detection (LungCAD, Siemens Medical solutions, Forchheim, Germany) and volumetry (LungCARE) of pulmonary nodules in dose-reduced pediatric MDCT. Materials and Methods: 30 scans of 24 children (10.4±5.9 years, 13 girls, 11 boys, 39.7±29.3 kg body weight) were performed on a 16-MDCT for tumor staging (n=18), inflammation (n=9), other indications (n=3). Tube voltage 120 kVp and effective mAs were adapted to body weight. Slice thickness 2 mm, increment 1 mm. A pediatric radiologist (U1), a CAD expert (U2) and an inexperienced radiologist (U3) independently analyzed the lung window images without and with the CAD as a second reader. In a consensus decision U1 and U2 were the reference standard. Results: Five examinations had to be excluded from the study due to other underlying lung disease. A total of 24 pulmonary nodules were found in all data sets with a minimal diameter of 0.35 mm to 3.81 mm (mean 1.7±0.85 mm). The sensitivities were as follows: U1 95.8% and 100% with CAD; U2 91.7% U3 66.7%. U2 and U3 did not detect further nodules with CAD. The sensitivity of CAD alone was 41.7% with 0.32 false-positive findings per examination. Interobserver agreement between U1/U2 regarding nodule detection with CAD was good (k=0.6500) and without CAD very good (k=0.8727). For the rest (U1/U3; U2/U3 with and without CAD), it was weak (k=0.0667-0.1884). Depending on the measured value (axial measurement, volume), there is a significant correlation (p=0.0026-0.0432) between nodule size and CAD detection. Undetected pulmonary nodules (mean 1.35 mm; range 0.35-2.61 mm) were smaller than the detected ones (mean 2.19 mm; range 1.35-3.81 mm). No significant correlation was found between CAD findings and patient age (p=0.9263) and body weight (p=0.9271) as well as nodule location (subpleural, intraparenchymal; p=1.0) and noise/SNR. (orig.)

  13. Performance of computer-aided detection applied to full-field digital mammography in detection of breast cancers

    International Nuclear Information System (INIS)

    Sadaf, Arifa; Crystal, Pavel; Scaranelo, Anabel; Helbich, Thomas

    2011-01-01

    Objective: The aim of this retrospective study was to evaluate performance of computer-aided detection (CAD) with full-field digital mammography (FFDM) in detection of breast cancers. Materials and Methods: CAD was retrospectively applied to standard mammographic views of 127 cases with biopsy proven breast cancers detected with FFDM (Senographe 2000, GE Medical Systems). CAD sensitivity was assessed in total group of 127 cases and for subgroups based on breast density, mammographic lesion type, mammographic lesion size, histopathology and mode of presentation. Results: Overall CAD sensitivity was 91% (115 of 127 cases). There were no statistical differences (p > 0.1) in CAD detection of cancers in dense breasts 90% (53/59) versus non-dense breasts 91% (62/68). There was statistical difference (p 20 mm 97% (22/23). Conclusion: CAD applied to FFDM showed 100% sensitivity in identifying cancers manifesting as microcalcifications only and high sensitivity 86% (71/83) for other mammographic appearances of cancer. Sensitivity is influenced by lesion size. CAD in FFDM is an adjunct helping radiologist in early detection of breast cancers.

  14. The interplay of attention economics and computer-aided detection marks in screening mammography

    Science.gov (United States)

    Schwartz, Tayler M.; Sridharan, Radhika; Wei, Wei; Lukyanchenko, Olga; Geiser, William; Whitman, Gary J.; Haygood, Tamara Miner

    2016-03-01

    Introduction: According to attention economists, overabundant information leads to decreased attention for individual pieces of information. Computer-aided detection (CAD) alerts radiologists to findings potentially associated with breast cancer but is notorious for creating an abundance of false-positive marks. We suspected that increased CAD marks do not lengthen mammogram interpretation time, as radiologists will selectively disregard these marks when present in larger numbers. We explore the relevance of attention economics in mammography by examining how the number of CAD marks affects interpretation time. Methods: We performed a retrospective review of bilateral digital screening mammograms obtained between January 1, 2011 and February 28, 2014, using only weekend interpretations to decrease distractions and the likelihood of trainee participation. We stratified data according to reader and used ANOVA to assess the relationship between number of CAD marks and interpretation time. Results: Ten radiologists, with median experience after residency of 12.5 years (range 6 to 24,) interpreted 1849 mammograms. When accounting for number of images, Breast Imaging Reporting and Data System category, and breast density, increasing numbers of CAD marks was correlated with longer interpretation time only for the three radiologists with the fewest years of experience (median 7 years.) Conclusion: For the 7 most experienced readers, increasing CAD marks did not lengthen interpretation time. We surmise that as CAD marks increase, the attention given to individual marks decreases. Experienced radiologists may rapidly dismiss larger numbers of CAD marks as false-positive, having learned that devoting extra attention to such marks does not improve clinical detection.

  15. Automatic detection of pulmonary nodules at spiral CT: clinical application of a computer-aided diagnosis system

    International Nuclear Information System (INIS)

    Wormanns, Dag; Fiebich, Martin; Saidi, Mustafa; Diederich, Stefan; Heindel, Walter

    2002-01-01

    The aim of this study was to evaluate a computer-aided diagnosis (CAD) workstation with automatic detection of pulmonary nodules at low-dose spiral CT in a clinical setting for early detection of lung cancer. Eighty-eight consecutive spiral-CT examinations were reported by two radiologists in consensus. All examinations were reviewed using a CAD workstation with a self-developed algorithm for automatic detection of pulmonary nodules. The algorithm is designed to detect nodules with diameters of at least 5 mm. A total of 153 nodules were detected with at least one modality (radiologists in consensus, CAD, 85 nodules with diameter <5 mm, 68 with diameter ≥5 mm). The results of automatic nodule detection were compared to nodules detected with any modality as gold standard. Computer-aided diagnosis correctly identified 26 of 59 (38%) nodules with diameters ≥5 mm detected by visual assessment by the radiologists; of these, CAD detected 44% (24 of 54) nodules without pleural contact. In addition, 12 nodules ≥5 mm were detected which were not mentioned in the radiologist's report but represented real nodules. Sensitivity for detection of nodules ≥5 mm was 85% (58 of 68) for radiologists and 38% (26 of 68) for CAD. There were 5.8±3.6 false-positive results of CAD per CT study. Computer-aided diagnosis improves detection of pulmonary nodules at spiral CT and is a valuable second opinion in a clinical setting for lung cancer screening despite of its still limited sensitivity. (orig.)

  16. Value of a Computer-aided Detection System Based on Chest Tomosynthesis Imaging for the Detection of Pulmonary Nodules.

    Science.gov (United States)

    Yamada, Yoshitake; Shiomi, Eisuke; Hashimoto, Masahiro; Abe, Takayuki; Matsusako, Masaki; Saida, Yukihisa; Ogawa, Kenji

    2018-04-01

    Purpose To assess the value of a computer-aided detection (CAD) system for the detection of pulmonary nodules on chest tomosynthesis images. Materials and Methods Fifty patients with and 50 without pulmonary nodules underwent both chest tomosynthesis and multidetector computed tomography (CT) on the same day. Fifteen observers (five interns and residents, five chest radiologists, and five abdominal radiologists) independently evaluated tomosynthesis images of 100 patients for the presence of pulmonary nodules in a blinded and randomized manner, first without CAD, then with the inclusion of CAD marks. Multidetector CT images served as the reference standard. Free-response receiver operating characteristic analysis was used for the statistical analysis. Results The pooled diagnostic performance of 15 observers was significantly better with CAD than without CAD (figure of merit [FOM], 0.74 vs 0.71, respectively; P = .02). The average true-positive fraction and false-positive rate per all cases with CAD were 0.56 and 0.26, respectively, whereas those without CAD were 0.47 and 0.20, respectively. Subanalysis showed that the diagnostic performance of interns and residents was significantly better with CAD than without CAD (FOM, 0.70 vs 0.62, respectively; P = .001), whereas for chest radiologists and abdominal radiologists, the FOM with CAD values were greater but not significantly: 0.80 versus 0.78 (P = .38) and 0.74 versus 0.73 (P = .65), respectively. Conclusion CAD significantly improved diagnostic performance in the detection of pulmonary nodules on chest tomosynthesis images for interns and residents, but provided minimal benefit for chest radiologists and abdominal radiologists. © RSNA, 2017 Online supplemental material is available for this article.

  17. Computer-aided detection of pulmonary nodules: a comparative study using the public LIDC/IDRI database

    International Nuclear Information System (INIS)

    Jacobs, Colin; Prokop, Mathias; Rikxoort, Eva M. van; Ginneken, Bram van; Murphy, Keelin; Schaefer-Prokop, Cornelia M.

    2016-01-01

    To benchmark the performance of state-of-the-art computer-aided detection (CAD) of pulmonary nodules using the largest publicly available annotated CT database (LIDC/IDRI), and to show that CAD finds lesions not identified by the LIDC's four-fold double reading process. The LIDC/IDRI database contains 888 thoracic CT scans with a section thickness of 2.5 mm or lower. We report performance of two commercial and one academic CAD system. The influence of presence of contrast, section thickness, and reconstruction kernel on CAD performance was assessed. Four radiologists independently analyzed the false positive CAD marks of the best CAD system. The updated commercial CAD system showed the best performance with a sensitivity of 82 % at an average of 3.1 false positive detections per scan. Forty-five false positive CAD marks were scored as nodules by all four radiologists in our study. On the largest publicly available reference database for lung nodule detection in chest CT, the updated commercial CAD system locates the vast majority of pulmonary nodules at a low false positive rate. Potential for CAD is substantiated by the fact that it identifies pulmonary nodules that were not marked during the extensive four-fold LIDC annotation process. (orig.)

  18. Pulmonary nodules: effect of adaptive statistical iterative reconstruction (ASIR) technique on performance of a computer-aided detection (CAD) system-comparison of performance between different-dose CT scans.

    Science.gov (United States)

    Yanagawa, Masahiro; Honda, Osamu; Kikuyama, Ayano; Gyobu, Tomoko; Sumikawa, Hiromitsu; Koyama, Mitsuhiro; Tomiyama, Noriyuki

    2012-10-01

    To evaluate the effects of ASIR on CAD system of pulmonary nodules using clinical routine-dose CT and lower-dose CT. Thirty-five patients (body mass index, 22.17 ± 4.37 kg/m(2)) were scanned by multidetector-row CT with tube currents (clinical routine-dose CT, automatically adjusted mA; lower-dose CT, 10 mA) and X-ray voltage (120 kVp). Each 0.625-mm-thick image was reconstructed at 0%-, 50%-, and 100%-ASIR: 0%-ASIR is reconstructed using only the filtered back-projection algorithm (FBP), while 100%-ASIR is reconstructed using the maximum ASIR and 50%-ASIR implies a blending of 50% FBP and ASIR. CAD output was compared retrospectively with the results of the reference standard which was established using a consensus panel of three radiologists. Data were analyzed using Bonferroni/Dunn's method. Radiation dose was calculated by multiplying dose-length product by conversion coefficient of 0.021. The consensus panel found 265 non-calcified nodules ≤ 30 mm (ground-glass opacity [GGO], 103; part-solid, 34; and solid, 128). CAD sensitivity was significantly higher at 100%-ASIR [clinical routine-dose CT, 71% (overall), 49% (GGO); lower-dose CT, 52% (overall), 67% (solid)] than at 0%-ASIR [clinical routine-dose CT, 54% (overall), 25% (GGO); lower-dose CT, 36% (overall), 50% (solid)] (pASIR (clinical routine-dose CT, 8.5; lower-dose CT, 6.2) than at 0%-ASIR (clinical routine-dose CT, 4.6; lower-dose CT, 3.5; pASIR on lower-dose CT is almost equal to that at 0%-ASIR on clinical routine-dose CT. ASIR can increase CAD sensitivity despite increased false-positive findings. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  19. Pulmonary nodules: Effect of adaptive statistical iterative reconstruction (ASIR) technique on performance of a computer-aided detection (CAD) system—Comparison of performance between different-dose CT scans

    Energy Technology Data Exchange (ETDEWEB)

    Yanagawa, Masahiro, E-mail: m-yanagawa@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Honda, Osamu, E-mail: ohonda@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Kikuyama, Ayano, E-mail: a-kikuyama@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Gyobu, Tomoko, E-mail: t-gyobu@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Sumikawa, Hiromitsu, E-mail: h-sumikawa@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Koyama, Mitsuhiro, E-mail: m-koyama@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan); Tomiyama, Noriyuki, E-mail: tomiyama@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-city, Osaka 565-0871 (Japan)

    2012-10-15

    Purpose: To evaluate the effects of ASIR on CAD system of pulmonary nodules using clinical routine-dose CT and lower-dose CT. Materials and methods: Thirty-five patients (body mass index, 22.17 ± 4.37 kg/m{sup 2}) were scanned by multidetector-row CT with tube currents (clinical routine-dose CT, automatically adjusted mA; lower-dose CT, 10 mA) and X-ray voltage (120 kVp). Each 0.625-mm-thick image was reconstructed at 0%-, 50%-, and 100%-ASIR: 0%-ASIR is reconstructed using only the filtered back-projection algorithm (FBP), while 100%-ASIR is reconstructed using the maximum ASIR and 50%-ASIR implies a blending of 50% FBP and ASIR. CAD output was compared retrospectively with the results of the reference standard which was established using a consensus panel of three radiologists. Data were analyzed using Bonferroni/Dunn's method. Radiation dose was calculated by multiplying dose-length product by conversion coefficient of 0.021. Results: The consensus panel found 265 non-calcified nodules ≤30 mm (ground-glass opacity [GGO], 103; part-solid, 34; and solid, 128). CAD sensitivity was significantly higher at 100%-ASIR [clinical routine-dose CT, 71% (overall), 49% (GGO); lower-dose CT, 52% (overall), 67% (solid)] than at 0%-ASIR [clinical routine-dose CT, 54% (overall), 25% (GGO); lower-dose CT, 36% (overall), 50% (solid)] (p < 0.001). Mean number of false-positive findings per examination was significantly higher at 100%-ASIR (clinical routine-dose CT, 8.5; lower-dose CT, 6.2) than at 0%-ASIR (clinical routine-dose CT, 4.6; lower-dose CT, 3.5; p < 0.001). Effective doses were 10.77 ± 3.41 mSv in clinical routine-dose CT and 2.67 ± 0.17 mSv in lower-dose CT. Conclusion: CAD sensitivity at 100%-ASIR on lower-dose CT is almost equal to that at 0%-ASIR on clinical routine-dose CT. ASIR can increase CAD sensitivity despite increased false-positive findings.

  20. Pulmonary nodules: Effect of adaptive statistical iterative reconstruction (ASIR) technique on performance of a computer-aided detection (CAD) system—Comparison of performance between different-dose CT scans

    International Nuclear Information System (INIS)

    Yanagawa, Masahiro; Honda, Osamu; Kikuyama, Ayano; Gyobu, Tomoko; Sumikawa, Hiromitsu; Koyama, Mitsuhiro; Tomiyama, Noriyuki

    2012-01-01

    Purpose: To evaluate the effects of ASIR on CAD system of pulmonary nodules using clinical routine-dose CT and lower-dose CT. Materials and methods: Thirty-five patients (body mass index, 22.17 ± 4.37 kg/m 2 ) were scanned by multidetector-row CT with tube currents (clinical routine-dose CT, automatically adjusted mA; lower-dose CT, 10 mA) and X-ray voltage (120 kVp). Each 0.625-mm-thick image was reconstructed at 0%-, 50%-, and 100%-ASIR: 0%-ASIR is reconstructed using only the filtered back-projection algorithm (FBP), while 100%-ASIR is reconstructed using the maximum ASIR and 50%-ASIR implies a blending of 50% FBP and ASIR. CAD output was compared retrospectively with the results of the reference standard which was established using a consensus panel of three radiologists. Data were analyzed using Bonferroni/Dunn's method. Radiation dose was calculated by multiplying dose-length product by conversion coefficient of 0.021. Results: The consensus panel found 265 non-calcified nodules ≤30 mm (ground-glass opacity [GGO], 103; part-solid, 34; and solid, 128). CAD sensitivity was significantly higher at 100%-ASIR [clinical routine-dose CT, 71% (overall), 49% (GGO); lower-dose CT, 52% (overall), 67% (solid)] than at 0%-ASIR [clinical routine-dose CT, 54% (overall), 25% (GGO); lower-dose CT, 36% (overall), 50% (solid)] (p < 0.001). Mean number of false-positive findings per examination was significantly higher at 100%-ASIR (clinical routine-dose CT, 8.5; lower-dose CT, 6.2) than at 0%-ASIR (clinical routine-dose CT, 4.6; lower-dose CT, 3.5; p < 0.001). Effective doses were 10.77 ± 3.41 mSv in clinical routine-dose CT and 2.67 ± 0.17 mSv in lower-dose CT. Conclusion: CAD sensitivity at 100%-ASIR on lower-dose CT is almost equal to that at 0%-ASIR on clinical routine-dose CT. ASIR can increase CAD sensitivity despite increased false-positive findings

  1. Performance of computer-aided detection in false-negative screening mammograms of breast cancers

    International Nuclear Information System (INIS)

    Han, Boo Kyung; Kim, Ji Young; Shin, Jung Hee; Choe, Yeon Hyeon

    2004-01-01

    To analyze retrospectively the abnormalities visible on the false-negative screening mammograms of patients with breast cancer and to determine the performance of computer-aided detection (CAD) in the detection of cancers. Of 108 consecutive cases of breast cancer diagnosed over a period of 6 years, of which previous screening mammograms were available, 32 retrospectively visible abnormalities (at which locations cancer later developed) were found in the previous mammograms, and which were originally reported as negative. These 32 patients ranged in age from 38 to 72 years (mean 52 years). We analyzed their previous mammographic findings, and assessed the ability of CAD to mark cancers in previous mammograms, according to the clinical presentation, the type of abnormalities and the mammographic parenchymal density. In these 32 previous mammograms of breast cancers (20 asymptomatic, 12 symptomatic), the retrospectively visible abnormalities were identified as densities in 22, calcifications in 8, and densities with calcifications in 2. CAD marked abnormalities in 20 (63%) of the 32 cancers with false-negative screening mammograms; 14 (70%) of the 20 subsequent screening-detected cancers, 5 (50%) of the 10 interval cancers, and 1 (50%) of the 2 cancers palpable after the screening interval. CAD marked 12 (50%) of the 24 densities and 9 (90%) of the 10 calcifications. CAD marked abnormalities in 7 (50%) of the 14 predominantly fatty breasts, and 13 (72%) of the 18 dense breasts. CAD-assisted diagnosis could potentially decrease the number of false-negative mammograms caused by the failure to recognize the cancer in the screening program, although its usefulness in the prevention of interval cancers appears to be limited

  2. Dynamic MRI-based computer aided diagnostic systems for early detection of kidney transplant rejection: A survey

    Science.gov (United States)

    Mostapha, Mahmoud; Khalifa, Fahmi; Alansary, Amir; Soliman, Ahmed; Gimel'farb, Georgy; El-Baz, Ayman

    2013-10-01

    Early detection of renal transplant rejection is important to implement appropriate medical and immune therapy in patients with transplanted kidneys. In literature, a large number of computer-aided diagnostic (CAD) systems using different image modalities, such as ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT), and radionuclide imaging, have been proposed for early detection of kidney diseases. A typical CAD system for kidney diagnosis consists of a set of processing steps including: motion correction, segmentation of the kidney and/or its internal structures (e.g., cortex, medulla), construction of agent kinetic curves, functional parameter estimation, diagnosis, and assessment of the kidney status. In this paper, we survey the current state-of-the-art CAD systems that have been developed for kidney disease diagnosis using dynamic MRI. In addition, the paper addresses several challenges that researchers face in developing efficient, fast and reliable CAD systems for the early detection of kidney diseases.

  3. Computer-aided Detection Fidelity of Pulmonary Nodules in Chest Radiograph

    Directory of Open Access Journals (Sweden)

    Nikolaos Dellios

    2017-01-01

    Full Text Available Aim: The most ubiquitous chest diagnostic method is the chest radiograph. A common radiographic finding, quite often incidental, is the nodular pulmonary lesion. The detection of small lesions out of complex parenchymal structure is a daily clinical challenge. In this study, we investigate the efficacy of the computer-aided detection (CAD software package SoftView™ 2.4A for bone suppression and OnGuard™ 5.2 (Riverain Technologies, Miamisburg, OH, USA for automated detection of pulmonary nodules in chest radiographs. Subjects and Methods: We retrospectively evaluated a dataset of 100 posteroanterior chest radiographs with pulmonary nodular lesions ranging from 5 to 85 mm. All nodules were confirmed with a consecutive computed tomography scan and histologically classified as 75% malignant. The number of detected lesions by observation in unprocessed images was compared to the number and dignity of CAD-detected lesions in bone-suppressed images (BSIs. Results: SoftView™ BSI does not affect the objective lesion-to-background contrast. OnGuard™ has a stand-alone sensitivity of 62% and specificity of 58% for nodular lesion detection in chest radiographs. The false positive rate is 0.88/image and the false negative (FN rate is 0.35/image. From the true positive lesions, 20% were proven benign and 80% were malignant. FN lesions were 47% benign and 53% malignant. Conclusion: We conclude that CAD does not qualify for a stand-alone standard of diagnosis. The use of CAD accompanied with a critical radiological assessment of the software suggested pattern appears more realistic. Accordingly, it is essential to focus on studies assessing the quality-time-cost profile of real-time (as opposed to retrospective CAD implementation in clinical diagnostics.

  4. Implementation and display of Computer Aided Design (CAD) models in Monte Carlo radiation transport and shielding applications

    International Nuclear Information System (INIS)

    Burns, T.J.

    1994-01-01

    An Xwindow application capable of importing geometric information directly from two Computer Aided Design (CAD) based formats for use in radiation transport and shielding analyses is being developed at ORNL. The application permits the user to graphically view the geometric models imported from the two formats for verification and debugging. Previous models, specifically formatted for the radiation transport and shielding codes can also be imported. Required extensions to the existing combinatorial geometry analysis routines are discussed. Examples illustrating the various options and features which will be implemented in the application are presented. The use of the application as a visualization tool for the output of the radiation transport codes is also discussed

  5. Modification to the Monte Carlo N-Particle (MCNP) Visual Editor (MCNPVised) to Read in Computer Aided Design (CAD) Files

    International Nuclear Information System (INIS)

    Randolph Schwarz; Leland L. Carter; Alysia Schwarz

    2005-01-01

    Monte Carlo N-Particle Transport Code (MCNP) is the code of choice for doing complex neutron/photon/electron transport calculations for the nuclear industry and research institutions. The Visual Editor for Monte Carlo N-Particle is internationally recognized as the best code for visually creating and graphically displaying input files for MCNP. The work performed in this grant was used to enhance the capabilities of the MCNP Visual Editor to allow it to read in both 2D and 3D Computer Aided Design (CAD) files, allowing the user to electronically generate a valid MCNP input geometry

  6. Computer-aided detection systems to improve lung cancer early diagnosis: state-of-the-art and challenges

    International Nuclear Information System (INIS)

    Traverso, A; Lopez Torres, E; Cerello, P; Fantacci, M E

    2017-01-01

    Lung cancer is one of the most lethal types of cancer, because its early diagnosis is not good enough. In fact, the detection of pulmonary nodule, potential lung cancers, in Computed Tomography scans is a very challenging and time-consuming task for radiologists. To support radiologists, researchers have developed Computer-Aided Diagnosis (CAD) systems for the automated detection of pulmonary nodules in chest Computed Tomography scans. Despite the high level of technological developments and the proved benefits on the overall detection performance, the usage of Computer-Aided Diagnosis in clinical practice is far from being a common procedure. In this paper we investigate the causes underlying this discrepancy and present a solution to tackle it: the M5L WEB- and Cloud-based on-demand Computer-Aided Diagnosis. In addition, we prove how the combination of traditional imaging processing techniques with state-of-art advanced classification algorithms allows to build a system whose performance could be much larger than any Computer-Aided Diagnosis developed so far. This outcome opens the possibility to use the CAD as clinical decision support for radiologists. (paper)

  7. Computer-aided detection systems to improve lung cancer early diagnosis: state-of-the-art and challenges

    Science.gov (United States)

    Traverso, A.; Lopez Torres, E.; Fantacci, M. E.; Cerello, P.

    2017-05-01

    Lung cancer is one of the most lethal types of cancer, because its early diagnosis is not good enough. In fact, the detection of pulmonary nodule, potential lung cancers, in Computed Tomography scans is a very challenging and time-consuming task for radiologists. To support radiologists, researchers have developed Computer-Aided Diagnosis (CAD) systems for the automated detection of pulmonary nodules in chest Computed Tomography scans. Despite the high level of technological developments and the proved benefits on the overall detection performance, the usage of Computer-Aided Diagnosis in clinical practice is far from being a common procedure. In this paper we investigate the causes underlying this discrepancy and present a solution to tackle it: the M5L WEB- and Cloud-based on-demand Computer-Aided Diagnosis. In addition, we prove how the combination of traditional imaging processing techniques with state-of-art advanced classification algorithms allows to build a system whose performance could be much larger than any Computer-Aided Diagnosis developed so far. This outcome opens the possibility to use the CAD as clinical decision support for radiologists.

  8. Computer aided detection system for lung cancer using computer tomography scans

    Science.gov (United States)

    Mahesh, Shanthi; Rakesh, Spoorthi; Patil, Vidya C.

    2018-04-01

    Lung Cancer is a disease can be defined as uncontrolled cell growth in tissues of the lung. If we detect the Lung Cancer in its early stage, then that could be the key of its cure. In this work the non-invasive methods are studied for assisting in nodule detection. It supplies a Computer Aided Diagnosis System (CAD) for early detection of lung cancer nodules from the Computer Tomography (CT) images. CAD system is the one which helps to improve the diagnostic performance of radiologists in their image interpretations. The main aim of this technique is to develop a CAD system for finding the lung cancer using the lung CT images and classify the nodule as Benign or Malignant. For classifying cancer cells, SVM classifier is used. Here, image processing techniques have been used to de-noise, to enhance, for segmentation and edge detection of an image is used to extract the area, perimeter and shape of nodule. The core factors of this research are Image quality and accuracy.

  9. A ROC-based feature selection method for computer-aided detection and diagnosis

    Science.gov (United States)

    Wang, Songyuan; Zhang, Guopeng; Liao, Qimei; Zhang, Junying; Jiao, Chun; Lu, Hongbing

    2014-03-01

    Image-based computer-aided detection and diagnosis (CAD) has been a very active research topic aiming to assist physicians to detect lesions and distinguish them from benign to malignant. However, the datasets fed into a classifier usually suffer from small number of samples, as well as significantly less samples available in one class (have a disease) than the other, resulting in the classifier's suboptimal performance. How to identifying the most characterizing features of the observed data for lesion detection is critical to improve the sensitivity and minimize false positives of a CAD system. In this study, we propose a novel feature selection method mR-FAST that combines the minimal-redundancymaximal relevance (mRMR) framework with a selection metric FAST (feature assessment by sliding thresholds) based on the area under a ROC curve (AUC) generated on optimal simple linear discriminants. With three feature datasets extracted from CAD systems for colon polyps and bladder cancer, we show that the space of candidate features selected by mR-FAST is more characterizing for lesion detection with higher AUC, enabling to find a compact subset of superior features at low cost.

  10. Gathering Empirical Evidence Concerning Links between Computer Aided Design (CAD) and Creativity

    Science.gov (United States)

    Musta'amal, Aede Hatib; Norman, Eddie; Hodgson, Tony

    2009-01-01

    Discussion is often reported concerning potential links between computer-aided designing and creativity, but there is a lack of systematic enquiry to gather empirical evidence concerning such links. This paper reports an indication of findings from other research studies carried out in contexts beyond general education that have sought evidence…

  11. Modification to the Monte N-Particle (MCNP) Visual Editor (MCNPVised) to read in Computer Aided Design (CAD) files

    International Nuclear Information System (INIS)

    Schwarz, Randy A.; Carter, Leeland L.

    2004-01-01

    Monte Carlo N-Particle Transport Code (MCNP) (Reference 1) is the code of choice for doing complex neutron/photon/electron transport calculations for the nuclear industry and research institutions. The Visual Editor for Monte Carlo N-Particle (References 2 to 11) is recognized internationally as the best code for visually creating and graphically displaying input files for MCNP. The work performed in this grant enhanced the capabilities of the MCNP Visual Editor to allow it to read in a 2D Computer Aided Design (CAD) file, allowing the user to modify and view the 2D CAD file and then electronically generate a valid MCNP input geometry with a user specified axial extent

  12. Multiple-instance learning for computer-aided detection of tuberculosis

    Science.gov (United States)

    Melendez, J.; Sánchez, C. I.; Philipsen, R. H. H. M.; Maduskar, P.; van Ginneken, B.

    2014-03-01

    Detection of tuberculosis (TB) on chest radiographs (CXRs) is a hard problem. Therefore, to help radiologists or even take their place when they are not available, computer-aided detection (CAD) systems are being developed. In order to reach a performance comparable to that of human experts, the pattern recognition algorithms of these systems are typically trained on large CXR databases that have been manually annotated to indicate the abnormal lung regions. However, manually outlining those regions constitutes a time-consuming process that, besides, is prone to inconsistencies and errors introduced by interobserver variability and the absence of an external reference standard. In this paper, we investigate an alternative pattern classi cation method, namely multiple-instance learning (MIL), that does not require such detailed information for a CAD system to be trained. We have applied this alternative approach to a CAD system aimed at detecting textural lesions associated with TB. Only the case (or image) condition (normal or abnormal) was provided in the training stage. We compared the resulting performance with those achieved by several variations of a conventional system trained with detailed annotations. A database of 917 CXRs was constructed for experimentation. It was divided into two roughly equal parts that were used as training and test sets. The area under the receiver operating characteristic curve was utilized as a performance measure. Our experiments show that, by applying the investigated MIL approach, comparable results as with the aforementioned conventional systems are obtained in most cases, without requiring condition information at the lesion level.

  13. Computer-aided detection of breast masses: Four-view strategy for screening mammography

    International Nuclear Information System (INIS)

    Wei Jun; Chan Heangping; Zhou Chuan; Wu Yita; Sahiner, Berkman; Hadjiiski, Lubomir M.; Roubidoux, Marilyn A.; Helvie, Mark A.

    2011-01-01

    Purpose: To improve the performance of a computer-aided detection (CAD) system for mass detection by using four-view information in screening mammography. Methods: The authors developed a four-view CAD system that emulates radiologists' reading by using the craniocaudal and mediolateral oblique views of the ipsilateral breast to reduce false positives (FPs) and the corresponding views of the contralateral breast to detect asymmetry. The CAD system consists of four major components: (1) Initial detection of breast masses on individual views, (2) information fusion of the ipsilateral views of the breast (referred to as two-view analysis), (3) information fusion of the corresponding views of the contralateral breast (referred to as bilateral analysis), and (4) fusion of the four-view information with a decision tree. The authors collected two data sets for training and testing of the CAD system: A mass set containing 389 patients with 389 biopsy-proven masses and a normal set containing 200 normal subjects. All cases had four-view mammograms. The true locations of the masses on the mammograms were identified by an experienced MQSA radiologist. The authors randomly divided the mass set into two independent sets for cross validation training and testing. The overall test performance was assessed by averaging the free response receiver operating characteristic (FROC) curves of the two test subsets. The FP rates during the FROC analysis were estimated by using the normal set only. The jackknife free-response ROC (JAFROC) method was used to estimate the statistical significance of the difference between the test FROC curves obtained with the single-view and the four-view CAD systems. Results: Using the single-view CAD system, the breast-based test sensitivities were 58% and 77% at the FP rates of 0.5 and 1.0 per image, respectively. With the four-view CAD system, the breast-based test sensitivities were improved to 76% and 87% at the corresponding FP rates, respectively

  14. A new approach to develop computer-aided detection schemes of digital mammograms

    Science.gov (United States)

    Tan, Maxine; Qian, Wei; Pu, Jiantao; Liu, Hong; Zheng, Bin

    2015-06-01

    The purpose of this study is to develop a new global mammographic image feature analysis based computer-aided detection (CAD) scheme and evaluate its performance in detecting positive screening mammography examinations. A dataset that includes images acquired from 1896 full-field digital mammography (FFDM) screening examinations was used in this study. Among them, 812 cases were positive for cancer and 1084 were negative or benign. After segmenting the breast area, a computerized scheme was applied to compute 92 global mammographic tissue density based features on each of four mammograms of the craniocaudal (CC) and mediolateral oblique (MLO) views. After adding three existing popular risk factors (woman’s age, subjectively rated mammographic density, and family breast cancer history) into the initial feature pool, we applied a sequential forward floating selection feature selection algorithm to select relevant features from the bilateral CC and MLO view images separately. The selected CC and MLO view image features were used to train two artificial neural networks (ANNs). The results were then fused by a third ANN to build a two-stage classifier to predict the likelihood of the FFDM screening examination being positive. CAD performance was tested using a ten-fold cross-validation method. The computed area under the receiver operating characteristic curve was AUC = 0.779   ±   0.025 and the odds ratio monotonically increased from 1 to 31.55 as CAD-generated detection scores increased. The study demonstrated that this new global image feature based CAD scheme had a relatively higher discriminatory power to cue the FFDM examinations with high risk of being positive, which may provide a new CAD-cueing method to assist radiologists in reading and interpreting screening mammograms.

  15. Computer-Aided Detection in Digital Mammography: False-Positive Marks and Their Reproducibility in Negative Mammograms

    International Nuclear Information System (INIS)

    Kim, Seung Ja; Moon, Woo Kyung; Cho, Nariya; Chang, Jung Min; Seong, Min Hyun

    2009-01-01

    Background: There are relatively few studies reporting the frequency of false-positive computer-aided detection (CAD) marks and their reproducibility in normal cases. Purpose: To evaluate retrospectively the false-positive mark rate of a CAD system and the reproducibility of false-positive marks in two sets of negative digital mammograms. Material and Methods: Two sets of negative digital mammograms were obtained in 360 women (mean age 57 years, range 30-76 years) with an approximate interval of 1 year (mean time 343.7 days), and a CAD system was applied. False-positive CAD marks and the reproducibility were determined. Results: Of the 360 patients, 252 (70.0%) and 240 (66.7%) patients had 1-7 CAD marks on the initial and second mammograms, respectively. The false-positive CAD mark rate was 1.5 (1.1 for masses and 0.4 for calcifications) and 1.4 (1.0 for masses and 0.4 for calcifications) per examination in the initial and second mammograms, respectively. The reproducibility of the false-positive CAD marks was 12.0% for both mass (81/680) and microcalcification (33/278) marks. Conclusion: False-positive CAD marks were seen in approximately 70% of normal cases. However, the reproducibility was very low. Radiologists must be familiar with the findings of false-positive CAD marks, since they are very common and can increase the recall rate in screening

  16. Statistical-techniques-based computer-aided diagnosis (CAD) using texture feature analysis: application in computed tomography (CT) imaging to fatty liver disease

    Science.gov (United States)

    Chung, Woon-Kwan; Park, Hyong-Hu; Im, In-Chul; Lee, Jae-Seung; Goo, Eun-Hoe; Dong, Kyung-Rae

    2012-09-01

    This paper proposes a computer-aided diagnosis (CAD) system based on texture feature analysis and statistical wavelet transformation technology to diagnose fatty liver disease with computed tomography (CT) imaging. In the target image, a wavelet transformation was performed for each lesion area to set the region of analysis (ROA, window size: 50 × 50 pixels) and define the texture feature of a pixel. Based on the extracted texture feature values, six parameters (average gray level, average contrast, relative smoothness, skewness, uniformity, and entropy) were determined to calculate the recognition rate for a fatty liver. In addition, a multivariate analysis of the variance (MANOVA) method was used to perform a discriminant analysis to verify the significance of the extracted texture feature values and the recognition rate for a fatty liver. According to the results, each texture feature value was significant for a comparison of the recognition rate for a fatty liver ( p fatty liver had the same scale as that for the F-value, showing 100% (average gray level) at the maximum and 80% (average contrast) at the minimum. Therefore, the recognition rate is believed to be a useful clinical value for the automatic detection and computer-aided diagnosis (CAD) using the texture feature value. Nevertheless, further study on various diseases and singular diseases will be needed in the future.

  17. Computer-aided detection of lung nodules on chest CT: issues to be solved before clinical use

    International Nuclear Information System (INIS)

    Goo, Jin Mo

    2005-01-01

    Given the increasing resolution of modern CT scanners, and the requirements for large-scale lung-screening examinations and diagnostic studies, there is an increased need for the accurate and reproducible analysis of the large number of images. Nodule detection is one of the main challenges of CT imaging, as they can be missed due to their small size, low relative contrast, or because they are located in an area with complex anatomy. Recent developments in computer-aided diagnosis (CAD) schemes are expected to aid radiologists in various tasks of chest imaging. In this era of multidetector row CT, the thoracic applications of greatest interest include the detection and volume measurement of lung nodules (1-7). Technology for CAD as applied to lung nodule detection on chest CT has been approved by the Food and Drug Administration and is currently commercially available. The article by Lee et al. (5) in this issue of the Korean Journal of Radiology is one of the few studies to examine the influence of a commercially available CAD system on the detection of lung nodules. In this study, some additional nodules were detected with the help of a CAD system, but at the expense of increased false positivity. The nodule detection rate of the CAD system in this study was lower than that achieved by radiologist, and the authors insist that the CAD system should be improved further. Compared to the use of CAD on mammograms, CAD evaluations of chest CTs remain limited to the laboratory setting. In this field, apart from the issues of detection rate and false positive detections, many obstacles must be overcome before CAD can be used in a true clinical reading environment. In this editorial, I will list some of these issues, but I emphasize now that I believe these issues will be solved by improved CAD versions in the near future

  18. Clinical application of low-dose CT combined with computer-aided detection in lung cancer screening

    International Nuclear Information System (INIS)

    Xu Zushan; Hou Hongjun; Xu Yan; Ma Daqing

    2010-01-01

    Objective: To investigate the clinical value of chest low-dose CT (LDCT) combined with computer-aided detection (CAD) system for lung cancer screening in high risk population. Methods: Two hundred and nineteen healthy candidates underwent 64-slice LDCT scan. All images were reviewed in consensus by two radiologists with 15 years of thoracic CT diagnosis experience. Then the image data were analyzed with CAD alone. Finally images were reviewed by two radiologists with 5 years of CT diagnosis experience with and without CT Viewer software. The sensitivity, false positive rate of CAD for pulmonary nodule detection were calculated. SPSS 11.5 software and Chi-square test were used for the statistics. Results: Of 219 candidates ,104(47.5% ) were detected with lung nodules. There were 366 true nodules confirmed by the senior radiologists. The CAD system detected 271 (74.0%) true nodules and 424 false-positive nodules. The false-positive rate was 1.94/per case. The two junior radiologists indentifid 292 (79.8%), 286(78.1%) nodules without CAD and 336 (91.8%), 333 (91.0%) nodules with CAD respectively. There were significant differences for radiologists in indentifying nodules with or without CAD system (P<0.01). Conclusions: CAD is more sensitive than radiologists for indentifying the nodules in the central area or in the hilar region of the lung. While radiologists are more sensitive for the peripheral and sub-pleural nodules,or ground glass opacity nodules, or nodules smaller than 4 mm. CAD can not be used alone. The detection rate can be improved with the combination of radiologist and CAD in LDCT screen. (authors)

  19. Computer aided detection of clusters of microcalcifications on full field digital mammograms

    International Nuclear Information System (INIS)

    Ge Jun; Sahiner, Berkman; Hadjiiski, Lubomir M.; Chan, H.-P.; Wei Jun; Helvie, Mark A.; Zhou Chuan

    2006-01-01

    We are developing a computer-aided detection (CAD) system to identify microcalcification clusters (MCCs) automatically on full field digital mammograms (FFDMs). The CAD system includes six stages: preprocessing; image enhancement; segmentation of microcalcification candidates; false positive (FP) reduction for individual microcalcifications; regional clustering; and FP reduction for clustered microcalcifications. At the stage of FP reduction for individual microcalcifications, a truncated sum-of-squares error function was used to improve the efficiency and robustness of the training of an artificial neural network in our CAD system for FFDMs. At the stage of FP reduction for clustered microcalcifications, morphological features and features derived from the artificial neural network outputs were extracted from each cluster. Stepwise linear discriminant analysis (LDA) was used to select the features. An LDA classifier was then used to differentiate clustered microcalcifications from FPs. A data set of 96 cases with 192 images was collected at the University of Michigan. This data set contained 96 MCCs, of which 28 clusters were proven by biopsy to be malignant and 68 were proven to be benign. The data set was separated into two independent data sets for training and testing of the CAD system in a cross-validation scheme. When one data set was used to train and validate the convolution neural network (CNN) in our CAD system, the other data set was used to evaluate the detection performance. With the use of a truncated error metric, the training of CNN could be accelerated and the classification performance was improved. The CNN in combination with an LDA classifier could substantially reduce FPs with a small tradeoff in sensitivity. By using the free-response receiver operating characteristic methodology, it was found that our CAD system can achieve a cluster-based sensitivity of 70, 80, and 90 % at 0.21, 0.61, and 1.49 FPs/image, respectively. For case

  20. Computer-aided detection of pulmonary embolism at CT pulmonary angiography: can it improve performance of inexperienced readers?

    International Nuclear Information System (INIS)

    Blackmon, Kevin N.; McCain, Joshua W.; Koonce, James D.; Costello, Philip; Florin, Charles; Bogoni, Luca; Salganicoff, Marcos; Lee, Heon; Bastarrika, Gorka; Thilo, Christian; Joseph Schoepf, U.

    2011-01-01

    To evaluate the effect of a computer-aided detection (CAD) algorithm on the performance of novice readers for detection of pulmonary embolism (PE) at CT pulmonary angiography (CTPA). We included CTPA examinations of 79 patients (50 female, 52 ± 18 years). Studies were evaluated by two independent inexperienced readers who marked all vessels containing PE. After 3 months all studies were reevaluated by the same two readers, this time aided by CAD prototype. A consensus read by three expert radiologists served as the reference standard. Statistical analysis used χ 2 and McNemar testing. Expert consensus revealed 119 PEs in 32 studies. For PE detection, the sensitivity of CAD alone was 78%. Inexperienced readers' initial interpretations had an average per-PE sensitivity of 50%, which improved to 71% (p < 0.001) with CAD as a second reader. False positives increased from 0.18 to 0.25 per study (p = 0.03). Per-study, the readers initially detected 27/32 positive studies (84%); with CAD this number increased to 29.5 studies (92%; p = 0.125). Our results suggest that CAD significantly improves the sensitivity of PE detection for inexperienced readers with a small but appreciable increase in the rate of false positives. (orig.)

  1. Computer-aided detection of pulmonary embolism at CT pulmonary angiography: can it improve performance of inexperienced readers?

    Energy Technology Data Exchange (ETDEWEB)

    Blackmon, Kevin N.; McCain, Joshua W.; Koonce, James D.; Costello, Philip [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Florin, Charles; Bogoni, Luca; Salganicoff, Marcos [Siemens AG, H IM SYNGO CAD Research and Development, Malvern, PA (United States); Lee, Heon [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Seoul Medical Center, Department of Radiology, Seoul (Korea, Republic of); Bastarrika, Gorka [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); University of Navarra, Department of Radiology, Pamplona (Spain); Thilo, Christian; Joseph Schoepf, U. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Department of Medicine, Charleston, SC (United States)

    2011-06-15

    To evaluate the effect of a computer-aided detection (CAD) algorithm on the performance of novice readers for detection of pulmonary embolism (PE) at CT pulmonary angiography (CTPA). We included CTPA examinations of 79 patients (50 female, 52 {+-} 18 years). Studies were evaluated by two independent inexperienced readers who marked all vessels containing PE. After 3 months all studies were reevaluated by the same two readers, this time aided by CAD prototype. A consensus read by three expert radiologists served as the reference standard. Statistical analysis used {chi}{sup 2} and McNemar testing. Expert consensus revealed 119 PEs in 32 studies. For PE detection, the sensitivity of CAD alone was 78%. Inexperienced readers' initial interpretations had an average per-PE sensitivity of 50%, which improved to 71% (p < 0.001) with CAD as a second reader. False positives increased from 0.18 to 0.25 per study (p = 0.03). Per-study, the readers initially detected 27/32 positive studies (84%); with CAD this number increased to 29.5 studies (92%; p = 0.125). Our results suggest that CAD significantly improves the sensitivity of PE detection for inexperienced readers with a small but appreciable increase in the rate of false positives. (orig.)

  2. Benefit of computer-aided detection analysis for the detection of subsolid and solid lung nodules on thin- and thick-section CT.

    Science.gov (United States)

    Godoy, Myrna C B; Kim, Tae Jung; White, Charles S; Bogoni, Luca; de Groot, Patricia; Florin, Charles; Obuchowski, Nancy; Babb, James S; Salganicoff, Marcos; Naidich, David P; Anand, Vikram; Park, Sangmin; Vlahos, Ioannis; Ko, Jane P

    2013-01-01

    The objective of our study was to evaluate the impact of computer-aided detection (CAD) on the identification of subsolid and solid lung nodules on thin- and thick-section CT. For 46 chest CT examinations with ground-glass opacity (GGO) nodules, CAD marks computed using thin data were evaluated in two phases. First, four chest radiologists reviewed thin sections (reader(thin)) for nodules and subsequently CAD marks (reader(thin) + CAD(thin)). After 4 months, the same cases were reviewed on thick sections (reader(thick)) and subsequently with CAD marks (reader(thick) + CAD(thick)). Sensitivities were evaluated. Additionally, reader(thick) sensitivity with assessment of CAD marks on thin sections was estimated (reader(thick) + CAD(thin)). For 155 nodules (mean, 5.5 mm; range, 4.0-27.5 mm)-74 solid nodules, 22 part-solid (part-solid nodules), and 59 GGO nodules-CAD stand-alone sensitivity was 80%, 95%, and 71%, respectively, with three false-positives on average (0-12) per CT study. Reader(thin) + CAD(thin) sensitivities were higher than reader(thin) for solid nodules (82% vs 57%, p thick), reader(thick) + CAD(thick), reader(thick) + CAD(thin) were 40%, 58% (p thick); false-positive rates were 1.17, 1.19, and 1.26 per case for reader(thick), reader(thick) + CAD(thick), and reader(thick) + CAD(thin), respectively. Detection of GGO nodules and solid nodules is significantly improved with CAD. When interpretation is performed on thick sections, the benefit is greater when CAD marks are reviewed on thin rather than thick sections.

  3. A dimension reduction strategy for improving the efficiency of computer-aided detection for CT colonography

    Science.gov (United States)

    Song, Bowen; Zhang, Guopeng; Wang, Huafeng; Zhu, Wei; Liang, Zhengrong

    2013-02-01

    Various types of features, e.g., geometric features, texture features, projection features etc., have been introduced for polyp detection and differentiation tasks via computer aided detection and diagnosis (CAD) for computed tomography colonography (CTC). Although these features together cover more information of the data, some of them are statistically highly-related to others, which made the feature set redundant and burdened the computation task of CAD. In this paper, we proposed a new dimension reduction method which combines hierarchical clustering and principal component analysis (PCA) for false positives (FPs) reduction task. First, we group all the features based on their similarity using hierarchical clustering, and then PCA is employed within each group. Different numbers of principal components are selected from each group to form the final feature set. Support vector machine is used to perform the classification. The results show that when three principal components were chosen from each group we can achieve an area under the curve of receiver operating characteristics of 0.905, which is as high as the original dataset. Meanwhile, the computation time is reduced by 70% and the feature set size is reduce by 77%. It can be concluded that the proposed method captures the most important information of the feature set and the classification accuracy is not affected after the dimension reduction. The result is promising and further investigation, such as automatically threshold setting, are worthwhile and are under progress.

  4. Computer-aided detection of colorectal polyps: can it improve sensitivity of less-experienced readers? Preliminary findings.

    Science.gov (United States)

    Baker, Mark E; Bogoni, Luca; Obuchowski, Nancy A; Dass, Chandra; Kendzierski, Renee M; Remer, Erick M; Einstein, David M; Cathier, Pascal; Jerebko, Anna; Lakare, Sarang; Blum, Andrew; Caroline, Dina F; Macari, Michael

    2007-10-01

    To determine whether computer-aided detection (CAD) applied to computed tomographic (CT) colonography can help improve sensitivity of polyp detection by less-experienced radiologist readers, with colonoscopy or consensus used as the reference standard. The release of the CT colonographic studies was approved by the individual institutional review boards of each institution. Institutions from the United States were HIPAA compliant. Written informed consent was waived at all institutions. The CT colonographic studies in 30 patients from six institutions were collected; 24 images depicted at least one confirmed polyp 6 mm or larger (39 total polyps) and six depicted no polyps. By using an investigational software package, seven less-experienced readers from two institutions evaluated the CT colonographic images and marked or scored polyps by using a five-point scale before and after CAD. The time needed to interpret the CT colonographic findings without CAD and then to re-evaluate them with CAD was recorded. For each reader, the McNemar test, adjusted for clustered data, was used to compare sensitivities for readers without and with CAD; a Wilcoxon signed-rank test was used to analyze the number of false-positive results per patient. The average sensitivity of the seven readers for polyp detection was significantly improved with CAD-from 0.810 to 0.908 (P=.0152). The number of false-positive results per patient without and with CAD increased from 0.70 to 0.96 (95% confidence interval for the increase: -0.39, 0.91). The mean total time for the readings was 17 minutes 54 seconds; for interpretation of CT colonographic findings alone, the mean time was 14 minutes 16 seconds; and for review of CAD findings, the mean time was 3 minutes 38 seconds. Results of this feasibility study suggest that CAD for CT colonography significantly improves per-polyp detection for less-experienced readers. Copyright (c) RSNA, 2007.

  5. Call for a Computer-Aided Cancer Detection and Classification Research Initiative in Oman.

    Science.gov (United States)

    Mirzal, Andri; Chaudhry, Shafique Ahmad

    2016-01-01

    Cancer is a major health problem in Oman. It is reported that cancer incidence in Oman is the second highest after Saudi Arabia among Gulf Cooperation Council countries. Based on GLOBOCAN estimates, Oman is predicted to face an almost two-fold increase in cancer incidence in the period 2008-2020. However, cancer research in Oman is still in its infancy. This is due to the fact that medical institutions and infrastructure that play central roles in data collection and analysis are relatively new developments in Oman. We believe the country requires an organized plan and efforts to promote local cancer research. In this paper, we discuss current research progress in cancer diagnosis using machine learning techniques to optimize computer aided cancer detection and classification (CAD). We specifically discuss CAD using two major medical data, i.e., medical imaging and microarray gene expression profiling, because medical imaging like mammography, MRI, and PET have been widely used in Oman for assisting radiologists in early cancer diagnosis and microarray data have been proven to be a reliable source for differential diagnosis. We also discuss future cancer research directions and benefits to Oman economy for entering the cancer research and treatment business as it is a multi-billion dollar industry worldwide.

  6. Computer aided detection of ureteral stones in thin slice computed tomography volumes using Convolutional Neural Networks.

    Science.gov (United States)

    Längkvist, Martin; Jendeberg, Johan; Thunberg, Per; Loutfi, Amy; Lidén, Mats

    2018-06-01

    Computed tomography (CT) is the method of choice for diagnosing ureteral stones - kidney stones that obstruct the ureter. The purpose of this study is to develop a computer aided detection (CAD) algorithm for identifying a ureteral stone in thin slice CT volumes. The challenge in CAD for urinary stones lies in the similarity in shape and intensity of stones with non-stone structures and how to efficiently deal with large high-resolution CT volumes. We address these challenges by using a Convolutional Neural Network (CNN) that works directly on the high resolution CT volumes. The method is evaluated on a large data base of 465 clinically acquired high-resolution CT volumes of the urinary tract with labeling of ureteral stones performed by a radiologist. The best model using 2.5D input data and anatomical information achieved a sensitivity of 100% and an average of 2.68 false-positives per patient on a test set of 88 scans. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Performance of computer-aided diagnosis for detection of lacunar infarcts on brain MR images: ROC analysis of radiologists' detection

    International Nuclear Information System (INIS)

    Uchiyama, Y.; Yokoyama, R.; Hara, T.; Fujita, H.; Asano, T.; Kato, H.; Hoshi, H.; Yamakawa, H.; Iwama, T.; Ando, H.; Yamakawa, H.

    2007-01-01

    The detection and management of asymptomatic lacunar infarcts on magnetic resonance (MR) images are important tasks for radiologists to ensure the prevention of sever cerebral infarctions. However, accurate identification of lacunar infarcts is a difficult. Therefore, we developed a computer-aided diagnosis (CAD) scheme for detection of lacunar infarcts. The purpose of this study was to evaluate radiologists' performance in detection of lacunar infarcts without and with use of CAD scheme. 30 T1- and 30 T2- weighted images obtained from 30 patients were used for an observer study, which were consisted of 15 cases with a single lacunar infarct and 15 cases without any lacunar infarct. Six radiologists participated in the observer study. They interpreted lacunar infarcts first without and then with use of the scheme. For all six observers, average area under the receiver operating characteristic curve value was increased from 0.920 to 0.965 when they used the computer output. This CAD scheme might have the potential to improve the accuracy of radiologists' performance in the detection of lacunar infarcts on MR images. (orig.)

  8. SPLPKG WFCMPR WFAPPX, Wilson-Fowler Spline Generator for Computer Aided Design And Manufacturing (CAD/CAM) Systems

    International Nuclear Information System (INIS)

    Fletcher, S.K.

    2002-01-01

    1 - Description of program or function: The three programs SPLPKG, WFCMPR, and WFAPPX provide the capability for interactively generating, comparing and approximating Wilson-Fowler Splines. The Wilson-Fowler spline is widely used in Computer Aided Design and Manufacturing (CAD/CAM) systems. It is favored for many applications because it produces a smooth, low curvature fit to planar data points. Program SPLPKG generates a Wilson-Fowler spline passing through given nodes (with given end conditions) and also generates a piecewise linear approximation to that spline within a user-defined tolerance. The program may be used to generate a 'desired' spline against which to compare other Splines generated by CAD/CAM systems. It may also be used to generate an acceptable approximation to a desired spline in the event that an acceptable spline cannot be generated by the receiving CAD/CAM system. SPLPKG writes an IGES file of points evaluated on the spline and/or a file containing the spline description. Program WFCMPR computes the maximum difference between two Wilson-Fowler Splines and may be used to verify the spline recomputed by a receiving system. It compares two Wilson-Fowler Splines with common nodes and reports the maximum distance between curves (measured perpendicular to segments) and the maximum difference of their tangents (or normals), both computed along the entire length of the Splines. Program WFAPPX computes the maximum difference between a Wilson- Fowler spline and a piecewise linear curve. It may be used to accept or reject a proposed approximation to a desired Wilson-Fowler spline, even if the origin of the approximation is unknown. The maximum deviation between these two curves, and the parameter value on the spline where it occurs are reported. 2 - Restrictions on the complexity of the problem - Maxima of: 1600 evaluation points (SPLPKG), 1000 evaluation points (WFAPPX), 1000 linear curve breakpoints (WFAPPX), 100 spline Nodes

  9. Statistical-techniques-based computer-aided diagnosis (CAD) using texture feature analysis: application in computed tomography (CT) imaging to fatty liver disease

    International Nuclear Information System (INIS)

    Chung, Woon-Kwan; Park, Hyong-Hu; Im, In-Chul; Lee, Jae-Seung; Goo, Eun-Hoe; Dong, Kyung-Rae

    2012-01-01

    This paper proposes a computer-aided diagnosis (CAD) system based on texture feature analysis and statistical wavelet transformation technology to diagnose fatty liver disease with computed tomography (CT) imaging. In the target image, a wavelet transformation was performed for each lesion area to set the region of analysis (ROA, window size: 50 x 50 pixels) and define the texture feature of a pixel. Based on the extracted texture feature values, six parameters (average gray level, average contrast, relative smoothness, skewness, uniformity, and entropy) were determined to calculate the recognition rate for a fatty liver. In addition, a multivariate analysis of the variance (MANOVA) method was used to perform a discriminant analysis to verify the significance of the extracted texture feature values and the recognition rate for a fatty liver. According to the results, each texture feature value was significant for a comparison of the recognition rate for a fatty liver (p < 0.05). Furthermore, the F-value, which was used as a scale for the difference in recognition rates, was highest in the average gray level, relatively high in the skewness and the entropy, and relatively low in the uniformity, the relative smoothness and the average contrast. The recognition rate for a fatty liver had the same scale as that for the F-value, showing 100% (average gray level) at the maximum and 80% (average contrast) at the minimum. Therefore, the recognition rate is believed to be a useful clinical value for the automatic detection and computer-aided diagnosis (CAD) using the texture feature value. Nevertheless, further study on various diseases and singular diseases will be needed in the future.

  10. A method to test the reproducibility and to improve performance of computer-aided detection schemes for digitized mammograms

    International Nuclear Information System (INIS)

    Zheng Bin; Gur, David; Good, Walter F.; Hardesty, Lara A.

    2004-01-01

    The purpose of this study is to develop a new method for assessment of the reproducibility of computer-aided detection (CAD) schemes for digitized mammograms and to evaluate the possibility of using the implemented approach for improving CAD performance. Two thousand digitized mammograms (representing 500 cases) with 300 depicted verified masses were selected in the study. Series of images were generated for each digitized image by resampling after a series of slight image rotations. A CAD scheme developed in our laboratory was applied to all images to detect suspicious mass regions. We evaluated the reproducibility of the scheme using the detection sensitivity and false-positive rates for the original and resampled images. We also explored the possibility of improving CAD performance using three methods of combining results from the original and resampled images, including simple grouping, averaging output scores, and averaging output scores after grouping. The CAD scheme generated a detection score (from 0 to 1) for each identified suspicious region. A region with a detection score >0.5 was considered as positive. The CAD scheme detected 238 masses (79.3% case-based sensitivity) and identified 1093 false-positive regions (average 0.55 per image) in the original image dataset. In eleven repeated tests using original and ten sets of rotated and resampled images, the scheme detected a maximum of 271 masses and identified as many as 2359 false-positive regions. Two hundred and eighteen masses (80.4%) and 618 false-positive regions (26.2%) were detected in all 11 sets of images. Combining detection results improved reproducibility and the overall CAD performance. In the range of an average false-positive detection rate between 0.5 and 1 per image, the sensitivity of the scheme could be increased approximately 5% after averaging the scores of the regions detected in at least four images. At low false-positive rate (e.g., ≤average 0.3 per image), the grouping method

  11. Are unnecessary follow-up procedures induced by computer-aided diagnosis (CAD) in mammography? Comparison of mammographic diagnosis with and without use of CAD

    International Nuclear Information System (INIS)

    Marx, Christiane; Malich, Ansgar; Facius, Mirjam; Grebenstein, Uta; Sauner, Dieter; Pfleiderer, Stefan O.R.; Kaiser, Werner A.

    2004-01-01

    Objective: To evaluate the rate of unnecessary follow-up procedures recommended by radiologists using a CAD-system. Materials and methods: 185 patients (740 images) were consecutively selected from three groups (36 histologically proven cancers=group 1; 49 histologically proven benign lesions=group 2 and 100 screening cases (4 years-follow up=group 3). Mammograms were evaluated by a CAD system (Second Look [reg] , CADx, Canada). Five blinded radiologists assessed the images without/with CAD outputs. Diagnostic decisions were ranked from surely benign to surely malignant according to BIRADS classification, follow-up procedures were recommended for each observed lesion (a, screening; b, short interval follow-up examination in 6 months; c, pathologic clarification). Results: CAD-system detected 32/36 cancers (88.9%) (FP-rate: 1.04 massmarks and 0.27 calcmarks/image). The following values were reached by all observers without/with CAD in the mean: Sensitivity 80.6/80.0%, specificity 83.2/86.4%, PPV 53.1/58.1%, and NPV 94.6/94.7%. Observers described a similar number of additional lesions without/with the use of CAD (325/326). Whereas the number of unnecessary short-time follow up recommendations increased in all case-subgroups with CAD: 40.8/42.9% (group 1), 35.6/38.1% (group 2), 44.7/46.8% (group 3), respectively, the number of recommended biopsies decreased in all subgroups: group 1: 34.7/27.1%; group 2: 47.4/41.5%, group 3: 33.3/22.0%, respectively. Conclusion: In this rather small population additional usage of CAD led to a lower rate of unnecessary biopsies. The observed decrease of recommended unnecessary biopsies due to the usage of CAD in the screening group suggests a potential financial benefit by using CAD as diagnostic aid

  12. Computer aided detection of brain micro-bleeds in traumatic brain injury

    Science.gov (United States)

    van den Heuvel, T. L. A.; Ghafoorian, M.; van der Eerden, A. W.; Goraj, B. M.; Andriessen, T. M. J. C.; ter Haar Romeny, B. M.; Platel, B.

    2015-03-01

    Brain micro-bleeds (BMBs) are used as surrogate markers for detecting diffuse axonal injury in traumatic brain injury (TBI) patients. The location and number of BMBs have been shown to influence the long-term outcome of TBI. To further study the importance of BMBs for prognosis, accurate localization and quantification are required. The task of annotating BMBs is laborious, complex and prone to error, resulting in a high inter- and intra-reader variability. In this paper we propose a computer-aided detection (CAD) system to automatically detect BMBs in MRI scans of moderate to severe neuro-trauma patients. Our method consists of four steps. Step one: preprocessing of the data. Both susceptibility (SWI) and T1 weighted MRI scans are used. The images are co-registered, a brain-mask is generated, the bias field is corrected, and the image intensities are normalized. Step two: initial candidates for BMBs are selected as local minima in the processed SWI scans. Step three: feature extraction. BMBs appear as round or ovoid signal hypo-intensities on SWI. Twelve features are computed to capture these properties of a BMB. Step four: Classification. To identify BMBs from the set of local minima using their features, different classifiers are trained on a database of 33 expert annotated scans and 18 healthy subjects with no BMBs. Our system uses a leave-one-out strategy to analyze its performance. With a sensitivity of 90% and 1.3 false positives per BMB, our CAD system shows superior results compared to state-of-the-art BMB detection algorithms (developed for non-trauma patients).

  13. Detection Efficiency of Microcalcification using Computer Aided Diagnosis in the Breast Ultrasonography Images

    International Nuclear Information System (INIS)

    Lee, Jin Soo; Ko, Seong Jin; Kang, Se Sik; Kim, Jung Hoon; Choi, Seok Yoon; Kim, Chang Soo; Park, Hyung Hu

    2012-01-01

    Digital Mammography makes it possible to reproduce the entire breast image. And it is used to detect microcalcification and mass which are the most important point of view of nonpalpable early breast cancer, so it has been used as the primary screening test of breast disease. It is reported that microcalcification of breast lesion is important in diagnosis of early breast cancer. In this study, six types of texture features algorithms are used to detect microcalcification on breast US images and the study has analyzed recognition rate of lesion between normal US images and other US images which microcalification is seen. As a result of the experiment, Computer aided diagnosis recognition rate that distinguishes mammography and breast US disease was considerably high 70-98%. The average contrast and entropy parameters were low in ROC analysis, but sensitivity and specificity of four types parameters were over 90%. Therefore it is possible to detect microcalcification on US images. If not only six types of texture features algorithms but also the research of additional parameter algorithm is being continually proceeded and basis of practical use on CAD is being prepared, it can be a important meaning as pre-reading. Also, it is considered very useful things for early diagnosis of breast cancer.

  14. Performance of fusion algorithms for computer-aided detection and classification of mines in very shallow water obtained from testing in navy Fleet Battle Exercise-Hotel 2000

    Science.gov (United States)

    Ciany, Charles M.; Zurawski, William; Kerfoot, Ian

    2001-10-01

    The performance of Computer Aided Detection/Computer Aided Classification (CAD/CAC) Fusion algorithms on side-scan sonar images was evaluated using data taken at the Navy's's Fleet Battle Exercise-Hotel held in Panama City, Florida, in August 2000. A 2-of-3 binary fusion algorithm is shown to provide robust performance. The algorithm accepts the classification decisions and associated contact locations form three different CAD/CAC algorithms, clusters the contacts based on Euclidian distance, and then declares a valid target when a clustered contact is declared by at least 2 of the 3 individual algorithms. This simple binary fusion provided a 96 percent probability of correct classification at a false alarm rate of 0.14 false alarms per image per side. The performance represented a 3.8:1 reduction in false alarms over the best performing single CAD/CAC algorithm, with no loss in probability of correct classification.

  15. Detection of simulated pulmonary nodules by single-exposure dual-energy computed radiography of the chest: effect of a computer-aided diagnosis system (Part 2)

    International Nuclear Information System (INIS)

    Kido, Shoji; Kuriyama, Keiko; Kuroda, Chikazumi; Nakamura, Hironobu; Ito, Wataru; Shimura, Kazuo; Kato, Hisatoyo

    2002-01-01

    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' detectabilities. 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

  16. Computer-aided detection of early cancer in the esophagus using HD endoscopy images

    Science.gov (United States)

    van der Sommen, Fons; Zinger, Svitlana; Schoon, Erik J.; de With, Peter H. N.

    2013-02-01

    Esophageal cancer is the fastest rising type of cancer in the Western world. The recent development of High-Definition (HD) endoscopy has enabled the specialist physician to identify cancer at an early stage. Nevertheless, it still requires considerable effort and training to be able to recognize these irregularities associated with early cancer. As a first step towards a Computer-Aided Detection (CAD) system that supports the physician in finding these early stages of cancer, we propose an algorithm that is able to identify irregularities in the esophagus automatically, based on HD endoscopic images. The concept employs tile-based processing, so our system is not only able to identify that an endoscopic image contains early cancer, but it can also locate it. The identification is based on the following steps: (1) preprocessing, (2) feature extraction with dimensionality reduction, (3) classification. We evaluate the detection performance in RGB, HSI and YCbCr color space using the Color Histogram (CH) and Gabor features and we compare with other well-known features to describe texture. For classification, we employ a Support Vector Machine (SVM) and evaluate its performance using different parameters and kernel functions. In experiments, our system achieves a classification accuracy of 95.9% on 50×50 pixel tiles of tumorous and normal tissue and reaches an Area Under the Curve (AUC) of 0.990. In 22 clinical examples our algorithm was able to identify all (pre-)cancerous regions and annotate those regions reasonably well. The experimental and clinical validation are considered promising for a CAD system that supports the physician in finding early stage cancer.

  17. Computer-aided detection of masses in digital tomosynthesis mammography: Comparison of three approaches

    International Nuclear Information System (INIS)

    Chan Heangping; Wei Jun; Zhang Yiheng; Helvie, Mark A.; Moore, Richard H.; Sahiner, Berkman; Hadjiiski, Lubomir; Kopans, Daniel B.

    2008-01-01

    The authors are developing a computer-aided detection (CAD) system for masses on digital breast tomosynthesis mammograms (DBT). Three approaches were evaluated in this study. In the first approach, mass candidate identification and feature analysis are performed in the reconstructed three-dimensional (3D) DBT volume. A mass likelihood score is estimated for each mass candidate using a linear discriminant analysis (LDA) classifier. Mass detection is determined by a decision threshold applied to the mass likelihood score. A free response receiver operating characteristic (FROC) curve that describes the detection sensitivity as a function of the number of false positives (FPs) per breast is generated by varying the decision threshold over a range. In the second approach, prescreening of mass candidate and feature analysis are first performed on the individual two-dimensional (2D) projection view (PV) images. A mass likelihood score is estimated for each mass candidate using an LDA classifier trained for the 2D features. The mass likelihood images derived from the PVs are backprojected to the breast volume to estimate the 3D spatial distribution of the mass likelihood scores. The FROC curve for mass detection can again be generated by varying the decision threshold on the 3D mass likelihood scores merged by backprojection. In the third approach, the mass likelihood scores estimated by the 3D and 2D approaches, described above, at the corresponding 3D location are combined and evaluated using FROC analysis. A data set of 100 DBT cases acquired with a GE prototype system at the Breast Imaging Laboratory in the Massachusetts General Hospital was used for comparison of the three approaches. The LDA classifiers with stepwise feature selection were designed with leave-one-case-out resampling. In FROC analysis, the CAD system for detection in the DBT volume alone achieved test sensitivities of 80% and 90% at average FP rates of 1.94 and 3.40 per breast, respectively. With the

  18. CT colonography: effect of computer-aided detection of colonic polyps as a second and concurrent reader for general radiologists with moderate experience in CT colonography

    International Nuclear Information System (INIS)

    Mang, Thomas; Ringel, Helmut; Weber, Michael; Bogoni, Luca; Anand, Vikram X.; Hermosillo, Gerardo; Raykar, Vikas; Salganicoff, Marcos; Wolf, Matthias; Chandra, Dass; Curtin, Andrew J.; Lev-Toaff, Anna S.; Noah, Ralph; Shaw, Robert; Summerton, Susan; Tappouni, Rafel F.R.; Obuchowski, Nancy A.

    2014-01-01

    To assess the effectiveness of computer-aided detection (CAD) as a second reader or concurrent reader in helping radiologists who are moderately experienced in computed tomographic colonography (CTC) to detect colorectal polyps. Seventy CTC datasets (34 patients: 66 polyps ≥6 mm; 36 patients: no abnormalities) were retrospectively reviewed by seven radiologists with moderate CTC experience. After primary unassisted evaluation, a CAD second read and, after a time interval of ≥4 weeks, a CAD concurrent read were performed. Areas under the receiver operating characteristic (ROC) curve (AUC), along with per-segment, per-polyp and per-patient sensitivities, and also reading times, were calculated for each reader with and without CAD. Of seven readers, 86 % and 71 % achieved a higher accuracy (segment-level AUC) when using CAD as second and concurrent reader respectively. Average segment-level AUCs with second and concurrent CAD (0.853 and 0.864) were significantly greater (p < 0.0001) than average AUC in the unaided evaluation (0.781). Per-segment, per-polyp, and per-patient sensitivities for polyps ≥6 mm were significantly higher in both CAD reading paradigms compared with unaided evaluation. Second-read CAD reduced readers' average segment and patient specificity by 0.007 and 0.036 (p = 0.005 and 0.011), respectively. CAD significantly improves the sensitivities of radiologists moderately experienced in CTC for polyp detection, both as second reader and concurrent reader. (orig.)

  19. Improved detection of pulmonary nodules on energy-subtracted chest radiographs with a commercial computer-aided diagnosis software: comparison with human observers

    International Nuclear Information System (INIS)

    Szucs-Farkas, Zsolt; Patak, Michael A.; Yuksel-Hatz, Seyran; Ruder, Thomas; Vock, Peter

    2010-01-01

    To retrospectively analyze the performance of a commercial computer-aided diagnosis (CAD) software in the detection of pulmonary nodules in original and energy-subtracted (ES) chest radiographs. Original and ES chest radiographs of 58 patients with 105 pulmonary nodules measuring 5-30 mm and images of 25 control subjects with no nodules were randomized. Five blinded readers evaluated firstly the original postero-anterior images alone and then together with the subtracted radiographs. In a second phase, original and ES images were analyzed by a commercial CAD program. CT was used as reference standard. CAD results were compared to the readers' findings. True-positive (TP) and false-positive (FP) findings with CAD on subtracted and non-subtracted images were compared. Depending on the reader's experience, CAD detected between 11 and 21 nodules missed by readers. Human observers found three to 16 lesions missed by the CAD software. CAD used with ES images produced significantly fewer FPs than with non-subtracted images: 1.75 and 2.14 FPs per image, respectively (p=0.029). The difference for the TP nodules was not significant (40 nodules on ES images and 34 lesions in non-subtracted radiographs, p = 0.142). CAD can improve lesion detection both on energy subtracted and non-subtracted chest images, especially for less experienced readers. The CAD program marked less FPs on energy-subtracted images than on original chest radiographs. (orig.)

  20. CAD Computer Aided Design

    DEFF Research Database (Denmark)

    Sigrist, F.(red.)

    Publikationen indeholder foredrag, oplæg og sammenfatning af diskussionerne på et seminar, der havde til formål at informere byggeriets parter om udviklingen omkring brug af edb i byggesektoren....

  1. Performance of computer-aided detection of pulmonary nodules in low-dose CT: comparison with double reading by nodule volume

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yingru; Vliegenthart, Rozemarijn; Wang, Ying; Ooijen, Peter M.A. van; Oudkerk, Matthijs [University of Groningen/University Medical Center Groningen, Center for Medical Imaging - North East Netherlands, Department of Radiology, P.O. Box 30.001, Groningen (Netherlands); Bock, Geertruida H. de [University of Groningen/University Medical Center Groningen, Department of Epidemiology, P.O. Box 30.001, Groningen (Netherlands); Klaveren, Rob J. van [Lievensberg Hospital, Department of Pulmonology, P.O. Box 135, Bergen op Zoom (Netherlands); Bogoni, Luca [CAD Group, Siemens Medical Solutions USA, Inc., Malvern, PA (United States); Jong, Pim A. de; Mali, Willem P. [University of Utrecht, Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, Utrecht (Netherlands)

    2012-10-15

    To evaluate performance of computer-aided detection (CAD) beyond double reading for pulmonary nodules on low-dose computed tomography (CT) by nodule volume. A total of 400 low-dose chest CT examinations were randomly selected from the NELSON lung cancer screening trial. CTs were evaluated by two independent readers and processed by CAD. A total of 1,667 findings marked by readers and/or CAD were evaluated by a consensus panel of expert chest radiologists. Performance was evaluated by calculating sensitivity of pulmonary nodule detection and number of false positives, by nodule characteristics and volume. According to the screening protocol, 90.9 % of the findings could be excluded from further evaluation, 49.2 % being small nodules (less than 50 mm{sup 3}). Excluding small nodules reduced false-positive detections by CAD from 3.7 to 1.9 per examination. Of 151 findings that needed further evaluation, 33 (21.9 %) were detected by CAD only, one of them being diagnosed as lung cancer the following year. The sensitivity of nodule detection was 78.1 % for double reading and 96.7 % for CAD. A total of 69.7 % of nodules undetected by readers were attached nodules of which 78.3 % were vessel-attached. CAD is valuable in lung cancer screening to improve sensitivity of pulmonary nodule detection beyond double reading, at a low false-positive rate when excluding small nodules. circle Computer-aided detection (CAD) has known advantages for computed tomography (CT). (orig.)

  2. Performance of computer-aided detection of pulmonary nodules in low-dose CT: comparison with double reading by nodule volume

    International Nuclear Information System (INIS)

    Zhao, Yingru; Vliegenthart, Rozemarijn; Wang, Ying; Ooijen, Peter M.A. van; Oudkerk, Matthijs; Bock, Geertruida H. de; Klaveren, Rob J. van; Bogoni, Luca; Jong, Pim A. de; Mali, Willem P.

    2012-01-01

    To evaluate performance of computer-aided detection (CAD) beyond double reading for pulmonary nodules on low-dose computed tomography (CT) by nodule volume. A total of 400 low-dose chest CT examinations were randomly selected from the NELSON lung cancer screening trial. CTs were evaluated by two independent readers and processed by CAD. A total of 1,667 findings marked by readers and/or CAD were evaluated by a consensus panel of expert chest radiologists. Performance was evaluated by calculating sensitivity of pulmonary nodule detection and number of false positives, by nodule characteristics and volume. According to the screening protocol, 90.9 % of the findings could be excluded from further evaluation, 49.2 % being small nodules (less than 50 mm 3 ). Excluding small nodules reduced false-positive detections by CAD from 3.7 to 1.9 per examination. Of 151 findings that needed further evaluation, 33 (21.9 %) were detected by CAD only, one of them being diagnosed as lung cancer the following year. The sensitivity of nodule detection was 78.1 % for double reading and 96.7 % for CAD. A total of 69.7 % of nodules undetected by readers were attached nodules of which 78.3 % were vessel-attached. CAD is valuable in lung cancer screening to improve sensitivity of pulmonary nodule detection beyond double reading, at a low false-positive rate when excluding small nodules. circle Computer-aided detection (CAD) has known advantages for computed tomography (CT). (orig.)

  3. Computer-aided mass detection in mammography: False positive reduction via gray-scale invariant ranklet texture features

    International Nuclear Information System (INIS)

    Masotti, Matteo; Lanconelli, Nico; Campanini, Renato

    2009-01-01

    In this work, gray-scale invariant ranklet texture features are proposed for false positive reduction (FPR) in computer-aided detection (CAD) of breast masses. Two main considerations are at the basis of this proposal. First, false positive (FP) marks surviving our previous CAD system seem to be characterized by specific texture properties that can be used to discriminate them from masses. Second, our previous CAD system achieves invariance to linear/nonlinear monotonic gray-scale transformations by encoding regions of interest into ranklet images through the ranklet transform, an image transformation similar to the wavelet transform, yet dealing with pixels' ranks rather than with their gray-scale values. Therefore, the new FPR approach proposed herein defines a set of texture features which are calculated directly from the ranklet images corresponding to the regions of interest surviving our previous CAD system, hence, ranklet texture features; then, a support vector machine (SVM) classifier is used for discrimination. As a result of this approach, texture-based information is used to discriminate FP marks surviving our previous CAD system; at the same time, invariance to linear/nonlinear monotonic gray-scale transformations of the new CAD system is guaranteed, as ranklet texture features are calculated from ranklet images that have this property themselves by construction. To emphasize the gray-scale invariance of both the previous and new CAD systems, training and testing are carried out without any in-between parameters' adjustment on mammograms having different gray-scale dynamics; in particular, training is carried out on analog digitized mammograms taken from a publicly available digital database, whereas testing is performed on full-field digital mammograms taken from an in-house database. Free-response receiver operating characteristic (FROC) curve analysis of the two CAD systems demonstrates that the new approach achieves a higher reduction of FP marks

  4. Evidence-based investigation of the influence of computer-aided detection of polyps on screening of colon cancer with CT colonography

    International Nuclear Information System (INIS)

    Yoshida, Hiroyuki

    2008-01-01

    Computed tomographic colonography (CTC), also known as virtual colonoscopy, is a CT examination of the colon for colorectal neoplasms. Recent large-scale clinical trials have demonstrated that CTC yields sensitivity comparable to optical colonoscopy in the detection of clinically significant polyps in a screening population, making CTC a promising technique for screening of colon cancer. For CTC to be a clinically practical means of screening, it must reliably and consistently detect polyps with high accuracy. However, high-level expertise is required to interpret the resulting CT images to find polyps, resulting in variable diagnostic accuracy among radiologists in the detection of polyps. A key technology to overcome this problem and to bring CTC to prime time for screening of colorectal cancer is computer-aided detection (CAD) of polyps. CAD automatically detects the locations of suspicious polyps in CTC images and presents them to radiologists. CAD has the potential to increase diagnostic performance in the detection of polyps as well as to reduce variability of the diagnostic accuracy among radiologists. This paper presents an evidence-based investigation of the influence of CAD on screening of colon cancer with CTC by describing the benefits of using CAD in the diagnosis of CTC, the fundamental CAD scheme for the detection of polyps in CTC, its detection performance, the effect on the improvement of detection performance, as well as the current and future challenges in CAD. (author)

  5. Screening mammography-detected cancers: the sensitivity of the computer-aided detection system as applied to full-field digital mammography

    International Nuclear Information System (INIS)

    Yang, Sang Kyu; Cho, Nariya; Ko, Eun Sook; Kim, Do Yeon; Moon, Woo Kyung

    2006-01-01

    We wanted to evaluate the sensitivity of the computer-aided detection (CAD) system for performing full-field digital mammography (FFDM) on the breast cancers that were originally detected by screening mammography. The CAD system (Image Checker v3.1, R2 Technology, Los Altos, Calif.) together with a full-field digital mammography system (Senographe 2000D, GE Medical Systems, Buc, France) was prospectively applied to the mammograms of 70 mammographically detected breast cancer patients (age range, 37-69; median age, 51 years) who had negative findings on their clinical examinations. The sensitivity of the CAD system, according to histopathologic findings and radiologic primary features (i.e, mass, microcalcifications or mass with microcalcifications) and also the false-positive marking rate were then determined. The CAD system correctly depicted 67 of 70 breast cancer lesions (97.5%). The CAD system marked 29 of 30 breast cancers that presented with microcalcifications only (sensitivity 96.7%) and all 18 breast cancers the presented with mass together with microcalcifications (sensitivity 100%). Twenty of the 22 lesions that appeared as a mass only were marked correctly by the CAD system (sensitivity 90.9%). The CAD system correctly depicted all 22 lesions of ductal carcinoma in situ (sensitivity: 100%), all 13 lesions of invasive ductal carcinoma with ductal carcinoma in situ (sensitivity: 100%) and the 1 lesion of invasive lobular carcinoma (sensitivity: 100%). Thirty one of the 34 lesions of invasive ductal carcinoma were marked correctly by the CAD system (sensitivity: 91.8%). The rate of false-positive marks was 0.21 mass marks per image and 0.16 microcalcification marks per image. The overall rate of false-positive marks was 0.37 per image. The CAD system using FFDM is useful for the detection of asymptomatic breast cancers, and it has a high overall tumor detection rate. The false negative cases were found in relatively small invasive ductal carcinoma

  6. Screening mammography-detected cancers: the sensitivity of the computer-aided detection system as applied to full-field digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Sang Kyu; Cho, Nariya; Ko, Eun Sook; Kim, Do Yeon; Moon, Woo Kyung [College of Medicine Seoul National University and The Insititute of Radiation Medicine, Seoul National University Research Center, Seoul (Korea, Republic of)

    2006-04-15

    We wanted to evaluate the sensitivity of the computer-aided detection (CAD) system for performing full-field digital mammography (FFDM) on the breast cancers that were originally detected by screening mammography. The CAD system (Image Checker v3.1, R2 Technology, Los Altos, Calif.) together with a full-field digital mammography system (Senographe 2000D, GE Medical Systems, Buc, France) was prospectively applied to the mammograms of 70 mammographically detected breast cancer patients (age range, 37-69; median age, 51 years) who had negative findings on their clinical examinations. The sensitivity of the CAD system, according to histopathologic findings and radiologic primary features (i.e, mass, microcalcifications or mass with microcalcifications) and also the false-positive marking rate were then determined. The CAD system correctly depicted 67 of 70 breast cancer lesions (97.5%). The CAD system marked 29 of 30 breast cancers that presented with microcalcifications only (sensitivity 96.7%) and all 18 breast cancers the presented with mass together with microcalcifications (sensitivity 100%). Twenty of the 22 lesions that appeared as a mass only were marked correctly by the CAD system (sensitivity 90.9%). The CAD system correctly depicted all 22 lesions of ductal carcinoma in situ (sensitivity: 100%), all 13 lesions of invasive ductal carcinoma with ductal carcinoma in situ (sensitivity: 100%) and the 1 lesion of invasive lobular carcinoma (sensitivity: 100%). Thirty one of the 34 lesions of invasive ductal carcinoma were marked correctly by the CAD system (sensitivity: 91.8%). The rate of false-positive marks was 0.21 mass marks per image and 0.16 microcalcification marks per image. The overall rate of false-positive marks was 0.37 per image. The CAD system using FFDM is useful for the detection of asymptomatic breast cancers, and it has a high overall tumor detection rate. The false negative cases were found in relatively small invasive ductal carcinoma.

  7. An automated tuberculosis screening strategy combining X-ray-based computer-aided detection and clinical information

    Science.gov (United States)

    Melendez, Jaime; Sánchez, Clara I.; Philipsen, Rick H. H. M.; Maduskar, Pragnya; Dawson, Rodney; Theron, Grant; Dheda, Keertan; van Ginneken, Bram

    2016-04-01

    Lack of human resources and radiological interpretation expertise impair tuberculosis (TB) screening programmes in TB-endemic countries. Computer-aided detection (CAD) constitutes a viable alternative for chest radiograph (CXR) reading. However, no automated techniques that exploit the additional clinical information typically available during screening exist. To address this issue and optimally exploit this information, a machine learning-based combination framework is introduced. We have evaluated this framework on a database containing 392 patient records from suspected TB subjects prospectively recruited in Cape Town, South Africa. Each record comprised a CAD score, automatically computed from a CXR, and 12 clinical features. Comparisons with strategies relying on either CAD scores or clinical information alone were performed. Our results indicate that the combination framework outperforms the individual strategies in terms of the area under the receiving operating characteristic curve (0.84 versus 0.78 and 0.72), specificity at 95% sensitivity (49% versus 24% and 31%) and negative predictive value (98% versus 95% and 96%). Thus, it is believed that combining CAD and clinical information to estimate the risk of active disease is a promising tool for TB screening.

  8. Evaluation of computer-aided detection and dual energy software in detection of peripheral pulmonary embolism on dual-energy pulmonary CT angiography

    International Nuclear Information System (INIS)

    Lee, Choong Wook; Seo, Joon Beom; Song, Jae-Woo; Kim, Mi-Young; Lee, Ha Young; Park, Yang Shin; Chae, Eun Jin; Jang, Yu Mi; Kim, Namkug; Krauss, Bernard

    2011-01-01

    To evaluate the sensitivity of computer-aided detection(CAD) and dual-energy software('Lung PBV', 'Lung Vessels') for detecting peripheral pulmonary embolism(PE). Between Jan-2007 and Jan-2008, 309 patients underwent dual-energy CT angiography(DECTA) for the evaluation of suspected PE. Among them, 37 patients were retrospectively selected; 21 with PE at segmental-or-below levels and 16 without PE according to clinical reports. A standard computer assisted detection (CAD) package and two new types of software('Lung PBV', 'Lung Vessels') were applied on a dedicated workstation. This resulted in four alternative tests for detecting PE: DECTA alone and DECTA with CAD, 'Lung Vessels' and 'Lung PBV'. Two radiologists independently read all cases at different reading sessions. Two thoracic radiologists set the reference standard by combining all information from DECTA and software. The sensitivity of detection for all, segmental and subsegmental-or-below PE were assessed. The reference standard contained 136 PE(segmental 65, subsegmental-or-below 71). With DECTA alone, the sensitivity of detection for all, segmental and subsegmental-or-below pulmonary arteries was 54.5%/73.7%/34.4%; DECTA with CAD, 57.8%/76.8%/37.9%; DECTA with 'Lung PBV', 61.1%/79.9%/41.4%; DECTA with 'Lung Vessels', 64.0%/78.3%/48.5% respectively. The use of CAD, Lung Vessels and Lung PBV shows improved capability to detect peripheral PE. (orig.)

  9. Automated image-based colon cleansing for laxative-free CT colonography computer-aided polyp detection

    International Nuclear Information System (INIS)

    Linguraru, Marius George; Panjwani, Neil; Fletcher, Joel G.; Summer, Ronald M.

    2011-01-01

    Purpose: To evaluate the performance of a computer-aided detection (CAD) system for detecting colonic polyps at noncathartic computed tomography colonography (CTC) in conjunction with an automated image-based colon cleansing algorithm. Methods: An automated colon cleansing algorithm was designed to detect and subtract tagged-stool, accounting for heterogeneity and poor tagging, to be used in conjunction with a colon CAD system. The method is locally adaptive and combines intensity, shape, and texture analysis with probabilistic optimization. CTC data from cathartic-free bowel preparation were acquired for testing and training the parameters. Patients underwent various colonic preparations with barium or Gastroview in divided doses over 48 h before scanning. No laxatives were administered and no dietary modifications were required. Cases were selected from a polyp-enriched cohort and included scans in which at least 90% of the solid stool was visually estimated to be tagged and each colonic segment was distended in either the prone or supine view. The CAD system was run comparatively with and without the stool subtraction algorithm. Results: The dataset comprised 38 CTC scans from prone and/or supine scans of 19 patients containing 44 polyps larger than 10 mm (22 unique polyps, if matched between prone and supine scans). The results are robust on fine details around folds, thin-stool linings on the colonic wall, near polyps and in large fluid/stool pools. The sensitivity of the CAD system is 70.5% per polyp at a rate of 5.75 false positives/scan without using the stool subtraction module. This detection improved significantly (p = 0.009) after automated colon cleansing on cathartic-free data to 86.4% true positive rate at 5.75 false positives/scan. Conclusions: An automated image-based colon cleansing algorithm designed to overcome the challenges of the noncathartic colon significantly improves the sensitivity of colon CAD by approximately 15%.

  10. Solitary Pulmonary Nodule on Helical Dynamic CT Scans: Analysis of the Enhancement Patterns Using a Computer-Aided Diagnosis (CAD) System

    International Nuclear Information System (INIS)

    Choi, Eun Jung; Jin, Gong Yong; Han, Young Min; Lee, Young Sun; Kweon, Keun Sang

    2008-01-01

    We wanted to investigate the usefulness of a computer-aided diagnosis (CAD) system in assisting radiologists to diagnosis malignant solitary pulmonary nodules (SPNs), as compared with diagnosing SPNs with using direct personal drawing. Forty patients with SPNs were analyzed. After the pre-contrast scan was performed, an additional ten series of post-contrast images were obtained at 20-second intervals. Two investigators measured the attenuation values of the SPNs: a radiologist who drew the regions of interest (ROIs), and a technician who used a CAD system. The Bland and Altman plots were used to compare the net enhancement between a CAD system and direct personal drawing. The diagnostic characteristics of the malignant SPNs were calculated by considering the CAD and direct personal drawing and with using Fisher's exact test. On the Bland and Altman plot, the net enhancement difference between the CAD system and direct personal drawing was not significant (within ± 2 standard deriation). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of diagnosing malignant SPNs using CAD was 92%, 85%, 75%, 96% and 88%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of diagnosing malignant SPNs using direct drawing was 92%, 89%, 79%, 92% and 88%, respectively. The CAD system was a useful tool for diagnosing malignant SPNs

  11. Computer aided detection of masses in mammography using subregion Hotelling observers

    International Nuclear Information System (INIS)

    Baydush, Alan H.; Catarious, David M.; Abbey, Craig K.; Floyd, Carey E.

    2003-01-01

    We propose to investigate the use of the subregion Hotelling observer for the basis of a computer aided detection scheme for masses in mammography. A database of 1320 regions of interest (ROIs) was selected from the DDSM database collected by the University of South Florida using the Lumisys scanner cases. The breakdown of the cases was as follows: 656 normal ROIs, 307 benign ROIs, and 357 cancer ROIs. Each ROI was extracted at a size of 1024x1024 pixels and subsampled to 128x128 pixels. For the detection task, cancer and benign cases were considered positive and normal was considered negative. All positive cases had the lesion centered in the ROI. We chose to investigate the subregion Hotelling observer as a classifier to detect masses. The Hotelling observer incorporates information about the signal, the background, and the noise correlation for prediction of positive and negative and is the optimal detector when these are known. For our study, 225 subregion Hotelling observers were set up in a 15x15 grid across the center of the ROIs. Each separate observer was designed to 'observe', or discriminate, an 8x8 pixel area of the image. A leave one out training and testing methodology was used to generate 225 'features', where each feature is the output of the individual observers. The 225 features derived from separate Hotelling observers were then narrowed down by using forward searching linear discriminants (LDs). The reduced set of features was then analyzed using an additional LD with receiver operating characteristic (ROC) analysis. The 225 Hotelling observer features were searched by the forward searching LD, which selected a subset of 37 features. This subset of 37 features was then analyzed using an additional LD, which gave a ROC area under the curve of 0.9412+/-0.006 and a partial area of 0.6728. Additionally, at 98% sensitivity the overall classifier had a specificity of 55.9% and a positive predictive value of 69.3%. Preliminary results suggest that

  12. Computer-aided polyp detection on CT colonography: Comparison of three systems in a high-risk human population

    International Nuclear Information System (INIS)

    Park, Hee Sun; Kim, Se Hyung; Kim, Jong Hyo; Lee, June-Goo; Kim, Sang Gyun; Lee, Jeong Min; Lee, Jae Young; Han, Joon Koo; Choi, Byung Ihn

    2010-01-01

    Purpose: To compare the detection performances of two commercial and one academic computer-aided diagnosis (CAD) systems for polyp detection on CT colonography (CTC) in a high-risk human population and to assess their detection characteristics. Materials and methods: This retrospective study had institutional review board approval, but informed consent was waived. Sixty-eight patients who were suspected of having colonic polyps and scheduled for colonoscopic polyp removal were included. After CTC was performed using a 64-row MDCT, two commercial (PEV, CAR) and one academic (Hessian matrix-based) CAD systems were applied to each CTC dataset. Colonoscopy using the segmental unblinded technique was performed as a standard of reference. Per-polyp and per-patient sensitivities were calculated and compared for each CAD system. The mean number of false-positives (FPs) and false-negatives (FNs) was computed and the causes of all FPs and FNs were analyzed. Results: A total of 151 polyps in 61 patients were detected (77 polyps <6 mm, 48 6-9.9 mm, 26 ≥ 10 mm). Per-polyp sensitivity for PEV, CAR, and Hessian matrix-based CAD were: 71.6%, 78.4%, and 83.8% for polyps ≥6 mm, and 88.5%, 96.2%, and 96.2% for polyps ≥10 mm. Per-patient sensitivity for polyps ≥6 mm was 80.4%, 89.1%, and 93.5%, and 87%, 95.7%, and 95.7% for polyps ≥10 mm, respectively. Per-polyp and per-patient sensitivities were not significantly different among the three CAD systems regardless of size threshold. Mean number of FPs was 6.9 for PEV, 7.3 for CAR, and 14 for Hessian matrix-based CAD. The most common cause of FPs were feces, followed by extracolonic findings, prominent folds and ileocecal valve, and rectal tube. The distribution of the causes of FPs was significantly different among the three systems. Conclusion: Sensitivity of the three CAD systems for polyp detection was comparable regardless of the polyp size threshold; however, the number of FPs was higher in the Hessian matrix-based CAD

  13. Linking computer-aided design (CAD) to Geant4-based Monte Carlo simulations for precise implementation of complex treatment head geometries

    International Nuclear Information System (INIS)

    Constantin, Magdalena; Constantin, Dragos E; Keall, Paul J; Narula, Anisha; Svatos, Michelle; Perl, Joseph

    2010-01-01

    Most of the treatment head components of medical linear accelerators used in radiation therapy have complex geometrical shapes. They are typically designed using computer-aided design (CAD) applications. In Monte Carlo simulations of radiotherapy beam transport through the treatment head components, the relevant beam-generating and beam-modifying devices are inserted in the simulation toolkit using geometrical approximations of these components. Depending on their complexity, such approximations may introduce errors that can be propagated throughout the simulation. This drawback can be minimized by exporting a more precise geometry of the linac components from CAD and importing it into the Monte Carlo simulation environment. We present a technique that links three-dimensional CAD drawings of the treatment head components to Geant4 Monte Carlo simulations of dose deposition. (note)

  14. Computer-aided detection of masses in full-field digital mammography using screen-film mammograms for training

    International Nuclear Information System (INIS)

    Kallenberg, Michiel; Karssemeijer, Nico

    2008-01-01

    It would be of great value when available databases of screen-film mammography (SFM) images can be used to train full-field digital mammography (FFDM) computer-aided detection (CAD) systems, as compilation of new databases is costly. In this paper, we investigate this possibility. Firstly, we develop a method that converts an FFDM image into an SFM-like representation. In this conversion method, we establish a relation between exposure and optical density by simulation of an automatic exposure control unit. Secondly, we investigate the effects of using the SFM images as training samples compared to training with FFDM images. Our FFDM database consisted of 266 cases, of which 102 were biopsy-proven malignant masses and 164 normals. The images were acquired with systems of two different manufacturers. We found that, when we trained our FFDM CAD system with a small number of images, training with FFDM images, using a five-fold crossvalidation procedure, outperformed training with SFM images. However, when the full SFM database, consisting of 348 abnormal cases (including 204 priors) and 810 normal cases, was used for training, SFM training outperformed FFDMA training. These results show that an existing CAD system for detection of masses in SFM can be used for FFDM images without retraining.

  15. Computer aided design

    International Nuclear Information System (INIS)

    Barache, J.M.; Beltranda, G.; Blanc, P.

    1987-01-01

    In order to ensure that the data transmitted to the managment system is of the required quality and consistent with the general control command protocols, computer aided design (CAD) was employed for level N4. One describes the use of CAD for the control system of N4 [fr

  16. Computer-aided diagnostic system for detection of Hashimoto thyroiditis on ultrasound images from a Polish population.

    Science.gov (United States)

    Acharya, U Rajendra; Sree, S Vinitha; Krishnan, M Muthu Rama; Molinari, Filippo; Zieleźnik, Witold; Bardales, Ricardo H; Witkowska, Agnieszka; Suri, Jasjit S

    2014-02-01

    Computer-aided diagnostic (CAD) techniques aid physicians in better diagnosis of diseases by extracting objective and accurate diagnostic information from medical data. Hashimoto thyroiditis is the most common type of inflammation of the thyroid gland. The inflammation changes the structure of the thyroid tissue, and these changes are reflected as echogenic changes on ultrasound images. In this work, we propose a novel CAD system (a class of systems called ThyroScan) that extracts textural features from a thyroid sonogram and uses them to aid in the detection of Hashimoto thyroiditis. In this paradigm, we extracted grayscale features based on stationary wavelet transform from 232 normal and 294 Hashimoto thyroiditis-affected thyroid ultrasound images obtained from a Polish population. Significant features were selected using a Student t test. The resulting feature vectors were used to build and evaluate the following 4 classifiers using a 10-fold stratified cross-validation technique: support vector machine, decision tree, fuzzy classifier, and K-nearest neighbor. Using 7 significant features that characterized the textural changes in the images, the fuzzy classifier had the highest classification accuracy of 84.6%, sensitivity of 82.8%, specificity of 87.0%, and a positive predictive value of 88.9%. The proposed ThyroScan CAD system uses novel features to noninvasively detect the presence of Hashimoto thyroiditis on ultrasound images. Compared to manual interpretations of ultrasound images, the CAD system offers a more objective interpretation of the nature of the thyroid. The preliminary results presented in this work indicate the possibility of using such a CAD system in a clinical setting after evaluating it with larger databases in multicenter clinical trials.

  17. Implementation of a computer-aided detection tool for quantification of intracranial radiologic markers on brain CT images

    Science.gov (United States)

    Aghaei, Faranak; Ross, Stephen R.; Wang, Yunzhi; Wu, Dee H.; Cornwell, Benjamin O.; Ray, Bappaditya; Zheng, Bin

    2017-03-01

    Aneurysmal subarachnoid hemorrhage (aSAH) is a form of hemorrhagic stroke that affects middle-aged individuals and associated with significant morbidity and/or mortality especially those presenting with higher clinical and radiologic grades at the time of admission. Previous studies suggested that blood extravasated after aneurysmal rupture was a potentially clinical prognosis factor. But all such studies used qualitative scales to predict prognosis. The purpose of this study is to develop and test a new interactive computer-aided detection (CAD) tool to detect, segment and quantify brain hemorrhage and ventricular cerebrospinal fluid on non-contrasted brain CT images. First, CAD segments brain skull using a multilayer region growing algorithm with adaptively adjusted thresholds. Second, CAD assigns pixels inside the segmented brain region into one of three classes namely, normal brain tissue, blood and fluid. Third, to avoid "black-box" approach and increase accuracy in quantification of these two image markers using CT images with large noise variation in different cases, a graphic User Interface (GUI) was implemented and allows users to visually examine segmentation results. If a user likes to correct any errors (i.e., deleting clinically irrelevant blood or fluid regions, or fill in the holes inside the relevant blood or fluid regions), he/she can manually define the region and select a corresponding correction function. CAD will automatically perform correction and update the computed data. The new CAD tool is now being used in clinical and research settings to estimate various quantitatively radiological parameters/markers to determine radiological severity of aSAH at presentation and correlate the estimations with various homeostatic/metabolic derangements and predict clinical outcome.

  18. Fate of pulmonary nodules detected by computer-aided diagnosis and physician review on the computed tomography simulation images for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Park, Hyo Jung; Kim, Jin Sung; Park, Hee Chul; Oh, Dong Ryul

    2014-01-01

    To investigate the frequency and clinical significance of detected incidental lung nodules found on computed tomography (CT) simulation images for hepatocellular carcinoma (HCC) using computer-aided diagnosis (CAD) and a physician review. Sixty-seven treatment-naive HCC patients treated with transcatheter arterial chemoembolization and radiotherapy (RT) were included for the study. Portal phase of simulation CT images was used for CAD analysis and a physician review for lung nodule detection. For automated nodule detection, a commercially available CAD system was used. To assess the performance of lung nodule detection for lung metastasis, the sensitivity, negative predictive value (NPV), and positive predictive value (PPV) were calculated. Forty-six patients had incidental nodules detected by CAD with a total of 109 nodules. Only 20 (18.3%) nodules were considered to be significant nodules by a physician review. The number of significant nodules detected by both of CAD or a physician review was 24 in 9 patients. Lung metastases developed in 11 of 46 patients who had any type of nodule. The sensitivities were 58.3% and 100% based on patient number and on the number of nodules, respectively. The NPVs were 91.4% and 100%, respectively. And the PPVs were 77.8% and 91.7%, respectively. Incidental detection of metastatic nodules was not an uncommon event. From our study, CAD could be applied to CT simulation images allowing for an increase in detection of metastatic nodules.

  19. A computer-aided diagnosis system to detect pathologies in temporal subtraction images of chest radiographs

    Science.gov (United States)

    Looper, Jared; Harrison, Melanie; Armato, Samuel G.

    2016-03-01

    Radiologists often compare sequential radiographs to identify areas of pathologic change; however, this process is prone to error, as human anatomy can obscure the regions of change, causing the radiologists to overlook pathology. Temporal subtraction (TS) images can provide enhanced visualization of regions of change in sequential radiographs and allow radiologists to better detect areas of change in radiographs. Not all areas of change shown in TS images, however, are actual pathology. The purpose of this study was to create a computer-aided diagnostic (CAD) system that identifies which regions of change are caused by pathology and which are caused by misregistration of the radiographs used to create the TS image. The dataset used in this study contained 120 images with 74 pathologic regions on 54 images outlined by an experienced radiologist. High and low ("light" and "dark") gray-level candidate regions were extracted from the images using gray-level thresholding. Then, sampling techniques were used to address the class imbalance problem between "true" and "false" candidate regions. Next, the datasets of light candidate regions, dark candidate regions, and the combined set of light and dark candidate regions were used as training and testing data for classifiers by using five-fold cross validation. Of the classifiers tested (support vector machines, discriminant analyses, logistic regression, and k-nearest neighbors), the support vector machine on the combined candidates using synthetic minority oversampling technique (SMOTE) performed best with an area under the receiver operating characteristic curve value of 0.85, a sensitivity of 85%, and a specificity of 84%.

  20. Optimizing Case-based detection performance in a multiview CAD system for mammography

    NARCIS (Netherlands)

    Samulski, M.; Karssemeijer, N.

    2011-01-01

    When reading mammograms, radiologists combine information from multiple views to detect abnormalities. Most computer-aided detection (CAD) systems, however, use primitive methods for inclusion of multiview context or analyze each view independently. In previous research it was found that in

  1. Computer Aided Detection of Breast Masses in Digital Tomosynthesis

    Science.gov (United States)

    2008-06-01

    of unknown pathology , all other ROIs generated from that specific subject’s reconstructed volumes were excluded from the KB. For scheme B, all the FPs...query ROI of unknown pathology , all other ROIs generated from that specific subject’s reconstructed volumes were excluded from the KB. For scheme B...Qian, L. Li, and L.P. Clarke, "Image feature extraction for mass detection in digital mammography: Influence of wavelet analysis." Med. Phys. 26

  2. Computer-aided system for detecting runway incursions

    Science.gov (United States)

    Sridhar, Banavar; Chatterji, Gano B.

    1994-07-01

    A synthetic vision system for enhancing the pilot's ability to navigate and control the aircraft on the ground is described. The system uses the onboard airport database and images acquired by external sensors. Additional navigation information needed by the system is provided by the Inertial Navigation System and the Global Positioning System. The various functions of the system, such as image enhancement, map generation, obstacle detection, collision avoidance, guidance, etc., are identified. The available technologies, some of which were developed at NASA, that are applicable to the aircraft ground navigation problem are noted. Example images of a truck crossing the runway while the aircraft flies close to the runway centerline are described. These images are from a sequence of images acquired during one of the several flight experiments conducted by NASA to acquire data to be used for the development and verification of the synthetic vision concepts. These experiments provide a realistic database including video and infrared images, motion states from the Inertial Navigation System and the Global Positioning System, and camera parameters.

  3. Computer-aided detection system for masses in automated whole breast ultrasonography: development and evaluation of the effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeoung Hyun [Dept. of Radiology, Ewha Womans University Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of); Cha, Joo Hee; Kim, Nam Kug; Chang, Young Jun; Kim, Hak Hee [Dept. of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Ko, Myung Su [Health Screening and Promotion Center, Asan Medical Center, Seoul (Korea, Republic of); Choi, Young Wook [Korea Electrotechnology Research Institute, Ansan (Korea, Republic of)

    2014-04-15

    The aim of this study was to evaluate the performance of a proposed computer-aided detection (CAD) system in automated breast ultrasonography (ABUS). Eighty-nine two-dimensional images (20 cysts, 42 benign lesions, and 27 malignant lesions) were obtained from 47 patients who underwent ABUS (ACUSON S2000). After boundary detection and removal, we detected mass candidates by using the proposed adjusted Otsu's threshold; the threshold was adaptive to the variations of pixel intensities in an image. Then, the detected candidates were segmented. Features of the segmented objects were extracted and used for training/testing in the classification. In our study, a support vector machine classifier was adopted. Eighteen features were used to determine whether the candidates were true lesions or not. A five-fold cross validation was repeated 20 times for the performance evaluation. The sensitivity and the false positive rate per image were calculated, and the classification accuracy was evaluated for each feature. In the classification step, the sensitivity of the proposed CAD system was 82.67% (SD, 0.02%). The false positive rate was 0.26 per image. In the detection/segmentation step, the sensitivities for benign and malignant mass detection were 90.47% (38/42) and 92.59% (25/27), respectively. In the five-fold cross-validation, the standard deviation of pixel intensities for the mass candidates was the most frequently selected feature, followed by the vertical position of the centroids. In the univariate analysis, each feature had 50% or higher accuracy. The proposed CAD system can be used for lesion detection in ABUS and may be useful in improving the screening efficiency.

  4. Computer-aided detection of lung nodules on multidetector CT in concurrent-reader and second-reader modes: A comparative study

    International Nuclear Information System (INIS)

    Matsumoto, Sumiaki; Ohno, Yoshiharu; Aoki, Takatoshi; Yamagata, Hitoshi; Nogami, Munenobu; Matsumoto, Keiko; Yamashita, Yoshiko; Sugimura, Kazuro

    2013-01-01

    Purpose: To compare the reading times and detection performances of radiologists in concurrent-reader and second-reader modes of computer-aided detection (CAD) for lung nodules on multidetector computed tomography (CT). Materials and Methods: Fifty clinical multidetector CT datasets containing nodules up to 20 mm in diameter were retrospectively collected. For the detection and rating of non-calcified nodules larger than 4 mm in diameter, 6 radiologists (3 experienced radiologists and 3 resident radiologists) independently interpreted these datasets twice, once with concurrent-reader CAD and once with second-reader CAD. The reference standard of nodules in the datasets was determined by the consensus of two experienced chest radiologists. The reading times and detection performances in the two modes of CAD were statistically compared, where jackknife free-response receiver operating characteristic (JAFROC) analysis was used for the comparison of detection performances. Results: Two hundreds and seven nodules constituted the reference standard. Reading time was significantly shorter in the concurrent-reader mode than in the second-reader mode, with the mean reading time for the 6 radiologists being 132 s with concurrent-reader CAD and 210 s with second-reader CAD (p < 0.01). JAFROC analysis revealed no significant difference between the detection performances in the two modes, with the average figure-of-merit value for the 6 radiologists being 0.70 with concurrent-reader CAD and 0.72 with second-reader CAD (p = 0.35). Conclusion: In CAD for lung nodules on multidetector CT, the concurrent-reader mode is more time-efficient than the second-reader mode, and there can be no significant difference between the two modes in terms of detection performance of radiologists

  5. Computer-Aided Detection of Kidney Tumor on Abdominal Computed Tomography Scans

    International Nuclear Information System (INIS)

    Kim, D.Y.; Park, J.W.

    2004-01-01

    Purpose: To implement a computer-aided detection system for kidney segmentation and kidney tumor detection on abdominal computed tomography (CT) scans. Material and Methods: Abdominal CT images were digitized with a film digitizer, and a gray-level threshold method was used to segment the kidney. Based on texture analysis performed on sample images of kidney tumors, a portion of the kidney tumor was selected as seed region for start point of the region-growing process. The average and standard deviations were used to detect the kidney tumor. Starting at the detected seed region, the region-growing method was used to segment the kidney tumor with intensity values used as an acceptance criterion for a homogeneous test. This test was performed to merge the neighboring region as kidney tumor boundary. These methods were applied on 156 transverse images of 12 cases of kidney tumors scanned using a G.E. Hispeed CT scanner and digitized with a Lumisys LS-40 film digitizer. Results: The computer-aided detection system resulted in a kidney tumor detection sensitivity of 85% and no false-positive findings. Conclusion: This computer-aided detection scheme was useful for kidney tumor detection and gave the characteristics of detected kidney tumors

  6. Demonstration Project on Mammographic Computer-Aided Diagnosis for Breast Cancer Detection

    National Research Council Canada - National Science Library

    Doi, Kunio

    2000-01-01

    ...) in mammographic detection of breast cancer. Our plan is to develop advanced CAD schemes for detection and characterization of clustered microcalcifications and masses by incorporating artificial neural networks and various image processing techniques...

  7. Demonstration Project on Mammographic Computer-Aided Diagnosis for Breast Cancer Detection

    National Research Council Canada - National Science Library

    Doi, Kunio

    2001-01-01

    ...) in mammographic detection of breast cancer. Our plan is to develop advanced CAD schemes for detection and characterization of clustered microcalcifications and masses by incorporating artificial neural networks and various image processing techniques...

  8. Demonstration Project on Mammographic Computer-Aided Diagnosis for Breast Cancer Detection

    National Research Council Canada - National Science Library

    Doi, Kunio

    1999-01-01

    ...) in mammographic detection of breast cancer. Our plan is to develop advanced CAD schemes for detection and characterization of clustered microcalcifications and masses by incorporating artificial neural networks and various image processing techniques...

  9. Demonstration Project on Mammographic Computer-Aided Diagnosis for Breast Cancer Detection

    National Research Council Canada - National Science Library

    Doi, Kunio

    2002-01-01

    ...) in mammographic detection of breast cancer. Our plan is to develop advanced CAD schemes for detection and characterization of clustered microcalcifications and masses by incorporating artificial neural networks and various image processing techniques...

  10. Applying a new computer-aided detection scheme generated imaging marker to predict short-term breast cancer risk

    Science.gov (United States)

    Mirniaharikandehei, Seyedehnafiseh; Hollingsworth, Alan B.; Patel, Bhavika; Heidari, Morteza; Liu, Hong; Zheng, Bin

    2018-05-01

    This study aims to investigate the feasibility of identifying a new quantitative imaging marker based on false-positives generated by a computer-aided detection (CAD) scheme to help predict short-term breast cancer risk. An image dataset including four view mammograms acquired from 1044 women was retrospectively assembled. All mammograms were originally interpreted as negative by radiologists. In the next subsequent mammography screening, 402 women were diagnosed with breast cancer and 642 remained negative. An existing CAD scheme was applied ‘as is’ to process each image. From CAD-generated results, four detection features including the total number of (1) initial detection seeds and (2) the final detected false-positive regions, (3) average and (4) sum of detection scores, were computed from each image. Then, by combining the features computed from two bilateral images of left and right breasts from either craniocaudal or mediolateral oblique view, two logistic regression models were trained and tested using a leave-one-case-out cross-validation method to predict the likelihood of each testing case being positive in the next subsequent screening. The new prediction model yielded the maximum prediction accuracy with an area under a ROC curve of AUC  =  0.65  ±  0.017 and the maximum adjusted odds ratio of 4.49 with a 95% confidence interval of (2.95, 6.83). The results also showed an increasing trend in the adjusted odds ratio and risk prediction scores (p  breast cancer risk.

  11. Single reading with computer-aided detection performed by selected radiologists in a breast cancer screening program

    Energy Technology Data Exchange (ETDEWEB)

    Bargalló, Xavier, E-mail: xbarga@clinic.cat [Department of Radiology (CDIC), Hospital Clínic de Barcelona, C/ Villarroel, 170, 08036 Barcelona (Spain); Santamaría, Gorane; Amo, Montse del; Arguis, Pedro [Department of Radiology (CDIC), Hospital Clínic de Barcelona, C/ Villarroel, 170, 08036 Barcelona (Spain); Ríos, José [Biostatistics and Data Management Core Facility, IDIBAPS, (Hospital Clinic) C/ Mallorca, 183. Floor -1. Office #60. 08036 Barcelona (Spain); Grau, Jaume [Preventive Medicine and Epidemiology Unit, Hospital Clínic de Barcelona, C/ Villarroel, 170, 08036 Barcelona (Spain); Burrel, Marta; Cores, Enrique; Velasco, Martín [Department of Radiology (CDIC), Hospital Clínic de Barcelona, C/ Villarroel, 170, 08036 Barcelona (Spain)

    2014-11-15

    Highlights: • 1-The cancer detection rate of the screening program improved using a single reading protocol by experienced radiologists assisted by CAD. • 2-The cancer detection rate improved at the cost of increasing recall rate. • 3-CAD, used by breast radiologists, did not help to detect more cancers. - Abstract: Objectives: To assess the impact of shifting from a standard double reading plus arbitration protocol to a single reading by experienced radiologists assisted by computer-aided detection (CAD) in a breast cancer screening program. Methods: This was a prospective study approved by the ethics committee. Data from 21,321 consecutive screening mammograms in incident rounds (2010–2012) were read following a single reading plus CAD protocol and compared with data from 47,462 consecutive screening mammograms in incident rounds (2004–2010) that were interpreted following a double reading plus arbitration protocol. For the single reading, radiologists were selected on the basis of the appraisement of their previous performance. Results: Period 2010–2012 vs. period 2004–2010: Cancer detection rate (CDR): 6.1‰ (95% confidence interval: 5.1–7.2) vs. 5.25‰; Recall rate (RR): 7.02% (95% confidence interval: 6.7–7.4) vs. 7.24% (selected readers before arbitration) and vs. 3.94 (all readers after arbitration); Predictive positive value of recall: 8.69% vs. 13.32%. Average size of invasive cancers: 14.6 ± 9.5 mm vs. 14.3 ± 9.5 mm. Stage: 0 (22.3/26.1%); I (59.2/50.8%); II (19.2/17.1%); III (3.1/3.3%); IV (0/1.9%). Specialized breast radiologists performed better than general radiologists. Conclusions: The cancer detection rate of the screening program improved using a single reading protocol by experienced radiologists assisted by CAD, at the cost of a moderate increase of the recall rate mainly related to the lack of arbitration.

  12. Multiparametric magnetic resonance imaging of the prostate with computer-aided detection: experienced observer performance study

    International Nuclear Information System (INIS)

    Giannini, Valentina; Mazzetti, Simone; Armando, Enrico; Carabalona, Silvia; Russo, Filippo; Giacobbe, Alessandro; Muto, Giovanni; Regge, Daniele

    2017-01-01

    To compare the performance of experienced readers in detecting prostate cancer (PCa) using likelihood maps generated by a CAD system with that of unassisted interpretation of multiparametric magnetic resonance imaging (mp-MRI). Three experienced radiologists reviewed mp-MRI prostate cases twice. First, readers observed CAD marks on a likelihood map and classified as positive those suspicious for cancer. After 6 weeks, radiologists interpreted mp-MRI examinations unassisted, using their favourite protocol. Sensitivity, specificity, reading time and interobserver variability were compared for the two reading paradigms. The dataset comprised 89 subjects of whom 35 with at least one significant PCa. Sensitivity was 80.9% (95% CI 72.1-88.0%) and 87.6% (95% CI 79.8-93.2; p = 0.105) for unassisted and CAD paradigm respectively. Sensitivity was higher with CAD for lesions with GS > 6 (91.3% vs 81.2%; p = 0.046) or diameter ≥10 mm (95.0% vs 80.0%; p = 0.006). Specificity was not affected by CAD. The average reading time with CAD was significantly lower (220 s vs 60 s; p < 0.001). Experienced readers using likelihood maps generated by a CAD scheme can detect more patients with ≥10 mm PCa lesions than unassisted MRI interpretation; overall reporting time is shorter. To gain more insight into CAD-human interaction, different reading paradigms should be investigated. (orig.)

  13. Multiparametric magnetic resonance imaging of the prostate with computer-aided detection: experienced observer performance study

    Energy Technology Data Exchange (ETDEWEB)

    Giannini, Valentina; Mazzetti, Simone; Armando, Enrico; Carabalona, Silvia; Russo, Filippo [FPO, IRCCS, Department of Radiology at the Candiolo Cancer Institute, Candiolo, Turin (Italy); Giacobbe, Alessandro [San Giovanni Bosco Hospital, Department of Urology, Turin (Italy); Muto, Giovanni [University Campus Biomedico, Department of Urology, Rome (Italy); Regge, Daniele [FPO, IRCCS, Department of Radiology at the Candiolo Cancer Institute, Candiolo, Turin (Italy); University of Torino, A.O.U. Citta della Salute e della Scienza, Department of Surgical Sciences, Turin (Italy)

    2017-10-15

    To compare the performance of experienced readers in detecting prostate cancer (PCa) using likelihood maps generated by a CAD system with that of unassisted interpretation of multiparametric magnetic resonance imaging (mp-MRI). Three experienced radiologists reviewed mp-MRI prostate cases twice. First, readers observed CAD marks on a likelihood map and classified as positive those suspicious for cancer. After 6 weeks, radiologists interpreted mp-MRI examinations unassisted, using their favourite protocol. Sensitivity, specificity, reading time and interobserver variability were compared for the two reading paradigms. The dataset comprised 89 subjects of whom 35 with at least one significant PCa. Sensitivity was 80.9% (95% CI 72.1-88.0%) and 87.6% (95% CI 79.8-93.2; p = 0.105) for unassisted and CAD paradigm respectively. Sensitivity was higher with CAD for lesions with GS > 6 (91.3% vs 81.2%; p = 0.046) or diameter ≥10 mm (95.0% vs 80.0%; p = 0.006). Specificity was not affected by CAD. The average reading time with CAD was significantly lower (220 s vs 60 s; p < 0.001). Experienced readers using likelihood maps generated by a CAD scheme can detect more patients with ≥10 mm PCa lesions than unassisted MRI interpretation; overall reporting time is shorter. To gain more insight into CAD-human interaction, different reading paradigms should be investigated. (orig.)

  14. A new 2D segmentation method based on dynamic programming applied to computer aided detection in mammography

    International Nuclear Information System (INIS)

    Timp, Sheila; Karssemeijer, Nico

    2004-01-01

    Mass segmentation plays a crucial role in computer-aided diagnosis (CAD) systems for classification of suspicious regions as normal, benign, or malignant. In this article we present a robust and automated segmentation technique--based on dynamic programming--to segment mass lesions from surrounding tissue. In addition, we propose an efficient algorithm to guarantee resulting contours to be closed. The segmentation method based on dynamic programming was quantitatively compared with two other automated segmentation methods (region growing and the discrete contour model) on a dataset of 1210 masses. For each mass an overlap criterion was calculated to determine the similarity with manual segmentation. The mean overlap percentage for dynamic programming was 0.69, for the other two methods 0.60 and 0.59, respectively. The difference in overlap percentage was statistically significant. To study the influence of the segmentation method on the performance of a CAD system two additional experiments were carried out. The first experiment studied the detection performance of the CAD system for the different segmentation methods. Free-response receiver operating characteristics analysis showed that the detection performance was nearly identical for the three segmentation methods. In the second experiment the ability of the classifier to discriminate between malignant and benign lesions was studied. For region based evaluation the area A z under the receiver operating characteristics curve was 0.74 for dynamic programming, 0.72 for the discrete contour model, and 0.67 for region growing. The difference in A z values obtained by the dynamic programming method and region growing was statistically significant. The differences between other methods were not significant

  15. Performance of computer-aided diagnosis for detection of lacunar infarcts on brain MR images: ROC analysis of radiologists' detection

    Energy Technology Data Exchange (ETDEWEB)

    Uchiyama, Y.; Yokoyama, R.; Hara, T.; Fujita, H. [Dept. of Intelligent Image Information, Graduate Scholl of Medicine, Gifu Univ. (Japan); Asano, T.; Kato, H.; Hoshi, H. [Dept. of Radiology, Graduate Scholl of Medicine, Gifu Univ. (Japan); Yamakawa, H.; Iwama, T. [Dept. of Neurosurgery, Graduate Scholl of Medicine, Gifu Univ. (Japan); Ando, H. [Dept. of Neurosurgery, Gifu Municipal Hospital (Japan); Yamakawa, H. [Dept. of Emergency and Critical Care Medicine, Chuno-Kousei Hospital (Japan)

    2007-06-15

    The detection and management of asymptomatic lacunar infarcts on magnetic resonance (MR) images are important tasks for radiologists to ensure the prevention of sever cerebral infarctions. However, accurate identification of lacunar infarcts is a difficult. Therefore, we developed a computer-aided diagnosis (CAD) scheme for detection of lacunar infarcts. The purpose of this study was to evaluate radiologists' performance in detection of lacunar infarcts without and with use of CAD scheme. 30 T1- and 30 T2- weighted images obtained from 30 patients were used for an observer study, which were consisted of 15 cases with a single lacunar infarct and 15 cases without any lacunar infarct. Six radiologists participated in the observer study. They interpreted lacunar infarcts first without and then with use of the scheme. For all six observers, average area under the receiver operating characteristic curve value was increased from 0.920 to 0.965 when they used the computer output. This CAD scheme might have the potential to improve the accuracy of radiologists' performance in the detection of lacunar infarcts on MR images. (orig.)

  16. Computer-aided detection of prostate cancer in T2-weighted MRI within the peripheral zone

    Science.gov (United States)

    Rampun, Andrik; Zheng, Ling; Malcolm, Paul; Tiddeman, Bernie; Zwiggelaar, Reyer

    2016-07-01

    In this paper we propose a prostate cancer computer-aided diagnosis (CAD) system and suggest a set of discriminant texture descriptors extracted from T2-weighted MRI data which can be used as a good basis for a multimodality system. For this purpose, 215 texture descriptors were extracted and eleven different classifiers were employed to achieve the best possible results. The proposed method was tested based on 418 T2-weighted MR images taken from 45 patients and evaluated using 9-fold cross validation with five patients in each fold. The results demonstrated comparable results to existing CAD systems using multimodality MRI. We achieved an area under the receiver operating curve (A z ) values equal to 90.0%+/- 7.6% , 89.5%+/- 8.9% , 87.9%+/- 9.3% and 87.4%+/- 9.2% for Bayesian networks, ADTree, random forest and multilayer perceptron classifiers, respectively, while a meta-voting classifier using average probability as a combination rule achieved 92.7%+/- 7.4% .

  17. Computer-aided detection of lung nodules in digital chest radiographs

    International Nuclear Information System (INIS)

    Giger, M.L.; Doi, K.; MacMahon, H.M.

    1986-01-01

    The authors are developing an automated method to detect lung nodules by eliminating the ''camouflaging: effect of the lung background. In order to increase the conspicuity of the nodules, we created, from a single chest radiograph, two images: one in which the signal-to-noise ratio (S/N) of the nodule is maximized and another in which that S/N is suppressed. The difference between these two processed images was subjected to feature-extraction technique in order to isolate the nodules. The detection accuracy of the computer-aided detection scheme, as compared with unaided radiologists' performance, was determined using receiver operating characteristic curve analysis

  18. Modelling, simulation and computer-aided design (CAD) of gyrotrons for novel applications in the high-power terahertz science and technologies

    Science.gov (United States)

    Sabchevski, S.; Idehara, T.; Damyanova, M.; Zhelyazkov, I.; Balabanova, E.; Vasileva, E.

    2018-03-01

    Gyrotrons are the most powerful sources of CW coherent radiation in the sub-THz and THz frequency bands. In recent years, they have demonstrated a remarkable potential for bridging the so-called THz-gap in the electromagnetic spectrum and opened the road to many novel applications of the terahertz waves. Among them are various advanced spectroscopic techniques (e.g., ESR and DNP-NMR), plasma physics and fusion research, materials processing and characterization, imaging and inspection, new medical technologies and biological studies. In this paper, we review briefly the current status of the research in this broad field and present our problem-oriented software packages developed recently for numerical analysis, computer-aided design (CAD) and optimization of gyrotrons.

  19. Computer-aided detection system performance on current and previous digital mammograms in patients with contralateral metachronous breast cancer

    International Nuclear Information System (INIS)

    Kim, Seung Ja; Moon, Woo Kyung; Cho, Nariya; Chang, Jung Min

    2012-01-01

    Background: The computer-aided detection (CAD) system is widely used for screening mammography. The performance of the CAD system for contralateral breast cancer has not been reported for women with a history of breast cancer. Purpose: To retrospectively evaluate the performance of a CAD system on current and previous mammograms in patients with contralateral metachronous breast cancer. Material and Methods: During a 3-year period, 4945 postoperative patients had follow-up examinations, from whom we selected 55 women with contralateral breast cancers. Among them, 38 had visible malignant signs on the current mammograms. We analyzed the sensitivity and false-positive marks of the system on the current and previous mammograms according to lesion type and breast density. Results: The total visible lesion components on the current mammograms included 27 masses and 14 calcifications in 38 patients. The case-based sensitivity for all lesion types was 63.2% (24/38) with false-positive marks of 0.71 per patient. The lesion-based sensitivity for masses and calcifications was 59.3% (16/27) and 71.4% (10/14), respectively. The lesion-based sensitivity for masses in fatty and dense breasts was 68.8% (11/16) and 45.5% (5/11), respectively. The lesion-based sensitivity for calcifications in fatty and dense breasts was 100.0% (3/3) and 63.6% (7/11), respectively. The total visible lesion components on the previous mammograms included 13 masses and three calcifications in 16 patients, and the sensitivity for all lesion types was 31.3% (5/16) with false-positive marks of 0.81 per patient. On these mammograms, the sensitivity for masses and calcifications was 30.8% (4/13) and 33.3% (1/3), respectively. The sensitivity in fatty and dense breasts was 28.6% (2/7) and 33.3% (3/9), respectively. Conclusion: In the women with a history of breast cancer, the sensitivity of the CAD system in visible contralateral breast cancer was lower than in most previous reports using the same CAD

  20. The efficacy of using CAD for detection of breast cancer in mammography screening A systematic review

    DEFF Research Database (Denmark)

    Henriksen, Emilie; Lauridsen, Carsten Ammitzbøl

    Abstract Purpose: The aim of this systematic review is to present an overview of the available studies concerning the use of computer-aided detection (CAD) systems in screening mammography for early detection of breast cancer and compare the diagnostic accuracy and recall rates of single reading....... The literature search resulted in 1522 records after duplicates were removed. 1491 records were excluded by abstract and 18 were excluded after assessing the eligibility by full text reading. A total of 13 articles were included in this study. Results: The results for the single reading vs. single reading...... with CAD group indicate that the addition of CAD increases sensitivity and cancer detection rate (CDR). For the double reading vs. single reading with CAD group none of the studies reported significant differences in sensitivity and CDR. Adding CAD to single reading increased the recall rates and decreased...

  1. Impact on breast cancer diagnosis in a multidisciplinary unit after the incorporation of mammography digitalization and computer-aided detection systems.

    Science.gov (United States)

    Romero, Cristina; Varela, Celia; Muñoz, Enriqueta; Almenar, Asunción; Pinto, Jose María; Botella, Miguel

    2011-12-01

    The purpose of this article is to evaluate the impact on the diagnosis of breast cancer of implementing full-field digital mammography (FFDM) in a multidisciplinary breast pathology unit and, 1 year later, the addition of a computer-aided detection (CAD) system. A total of 13,453 mammograms performed between January and July of the years 2004, 2006, and 2007 were retrospectively reviewed using conventional mammography, digital mammography, and digital mammography plus CAD techniques. Mammograms were classified into two subsets: screening and diagnosis. Variables analyzed included cancer detection rate, rate of in situ carcinoma, tumor size at detection, biopsy rate, and positive predictive value of biopsy. FFDM increased the cancer detection rate, albeit not statistically significantly. The detection rate of in situ carcinoma increased significantly using FFDM plus CAD compared with conventional technique (36.8% vs 6.7%; p = 0.05 without Bonferroni statistical correction) for the screening dataset. Relative to conventional mammography, tumor size at detection decreased with digital mammography (T1, 61.5% vs 88%; p = 0.018) and with digital mammography plus CAD (T1, 79.7%; p = 0.03 without Bonferroni statistical correction). Biopsy rates in the general population increased significantly using CAD (10.6/1000 for conventional mammography, 14.7/1000 for digital mammography, and 17.9/1000 for digital mammography plus CAD; p = 0.02). The positive predictive value of biopsy decreased slightly, but not significantly, for both subsets. The incorporation of new techniques has improved the performance of the breast unit by increasing the overall detection rates and earlier detection (smaller tumors), both leading to an increase in interventionism.

  2. Computer aided design for the nuclear industry

    International Nuclear Information System (INIS)

    Basson, Keith

    1986-01-01

    The paper concerns the new computer aided design (CAD) centre for the United Kingdom nuclear industry, and its applications. A description of the CAD system is given, including the current projects at the CAD centre. Typical applications of the 3D CAD plant based models, stress analysis studies, and the extraction of data from CAD drawings to produce associated documentation, are all described. Future developments using computer aided design systems are also considered. (U.K.)

  3. Advances in computer-aided engineering : CAD/CAM-research at Delft University of Technology. Report of the VF-project CAD/CAM 1989-1994

    NARCIS (Netherlands)

    Undetermined, U.

    1994-01-01

    This book contains a collection of articles describing on-going CAD/CAM-research at several engineering faculties at Delft University of Technology. Two main themes covered in this book are 'Conceptual design of complex products' and 'Product modelling and product data exchange'.

  4. Application of a kernel-based online learning algorithm to the classification of nodule candidates in computer-aided detection of CT lung nodules

    International Nuclear Information System (INIS)

    Matsumoto, S.; Ohno, Y.; Takenaka, D.; Sugimura, K.; Yamagata, H.

    2007-01-01

    Classification of the nodule candidates in computer-aided detection (CAD) of lung nodules in CT images was addressed by constructing a nonlinear discriminant function using a kernel-based learning algorithm called the kernel recursive least-squares (KRLS) algorithm. Using the nodule candidates derived from the processing by a CAD scheme of 100 CT datasets containing 253 non-calcified nodules or 3 mm or larger as determined by the consensus of two thoracic radiologists, the following trial were carried out 100 times: by randomly selecting 50 datasets for training, a nonlinear discriminant function was obtained using the nodule candidates in the training datasets and tested with the remaining candidates; for comparison, a rule-based classification was tested in a similar manner. At the number of false positives per case of about 5, the nonlinear classification method showed an improved sensitivity of 80% (mean over the 100 trials) compared with 74% of the rule-based method. (orig.)

  5. Usefulness of the CAD System for Detecting Pulmonary Nodule in Real Clinical Practice

    International Nuclear Information System (INIS)

    Song, Kyoung Doo; Chung, Myung Jin; Kim, Hee Cheol; Lee, Kyung Soo; Jeong, Sun Young

    2011-01-01

    We wanted to evaluate the usefulness of the computer-aided detection (CAD) system for detecting pulmonary nodules in real clinical practice by using the CT images. Our Institutional Review Board approved our retrospective study with a waiver of informed consent. This study included 166 CT examinations that were performed for the evaluation of pulmonary metastasis in 166 patients with colorectal cancer. All the CT examinations were interpreted by radiologists and they were also evaluated by the CAD system. All the nodules detected by the CAD system were evaluated with regard to whether or not they were true nodules, and they were classified into micro nodules (MN, diameter < 4 mm) and significant nodules (SN, 4 ≤ diameter ≤ 10 mm). The radiologic reports and CAD results were compared. The CAD system helped detect 426 nodules: 115 (27%) of the 426 nodules were classified as true nodules and 35 (30%) of the 115 nodules were SNs, and 83 (72%) of the 115 were not mentioned in the radiologists' reports and three (4%) of the 83 nodules were non-calcified SNs. One of three non-calcified SNs was confirmed as a metastatic nodule. According to the radiologists' reports, 60 true nodules were detected, and 28 of the 60 were not detected by the CAD system. Although the CAD system missed many SNs that are detected by radiologists, it helps detect additional nodules that are missed by the radiologists in real clinical practice. Therefore, the CAD system can be useful to support a radiologist's detection performance

  6. Time-efficient CT colonography interpretation using an advanced image-gallery-based, computer-aided ''first-reader'' workflow for the detection of colorectal adenomas

    International Nuclear Information System (INIS)

    Mang, Thomas; Ringl, Helmut; Weber, Michael; Mueller-Mang, Christina; Hermosillo, Gerardo; Wolf, Matthias; Bogoni, Luca; Salganicoff, Marcos; Raykar, Vikas; Graser, Anno

    2012-01-01

    To assess the performance of an advanced ''first-reader'' workflow for computer-aided detection (CAD) of colorectal adenomas ≥ 6 mm at computed tomographic colonography (CTC) in a low-prevalence cohort. A total of 616 colonoscopy-validated CTC patient-datasets were retrospectively reviewed by a radiologist using a ''first-reader'' CAD workflow. CAD detections were presented as galleries of six automatically generated two-dimensional (2D) and three-dimensional (3D) images together with interactive 3D target views and 2D multiplanar views of the complete dataset. Each patient-dataset was interpreted by initially using CAD image-galleries followed by a fast 2D review to address unprompted colonic areas. Per-patient, per-polyp, and per-adenoma sensitivities were calculated for lesions ≥ 6 mm. Statistical testing employed Fisher's exact and McNemar tests. In 91/616 patients, 131 polyps (92 adenomas, 39 non-adenomas) ≥ 6 mm and two cancers were identified by reference standard. Using the CAD gallery-based first-reader workflow, the radiologist detected all adenomas ≥ 10 mm (34/34) and cancers. Per-patient and polyp sensitivities for lesions ≥ 6 mm were 84.3 % (75/89), and 83.2 % (109/131), respectively, with 89.1 % (57/64) and 85.9 % (79/92) for adenomas. Overall specificity was 95.6 % (504/527). Mean interpretation time was 3.1 min per patient. A CAD algorithm, applied in an image-gallery-based first-reader workflow, can substantially decrease reading times while enabling accurate detection of colorectal adenomas in a low-prevalence population. (orig.)

  7. Manipulating the Geometric Computer-aided Design of the Operational Requirements-based Casualty Assessment Model within BRL-CAD

    Science.gov (United States)

    2018-03-30

    aided Design of the Operational Requirements-based Casualty Assessment Model within BRL-CAD 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ...upper_arm_r.s upper_arm_r.s-bool r upper_leg_l.r - lower_leg_l.s-bool r upper_leg_r.r - lower_leg_r.s-bool r upper_arm_r.r - lower_arm_r.s-bool r ...upper_arm_l.r - lower_arm_l.s-bool r pelvis.r - hip_l.s-bool - hip_r.s-bool - upper_leg_l.s-bool - upper_leg_r.s-bool r thorax.r - shoulder_l.s-bool

  8. Computer-aided detection of basal cell carcinoma through blood content analysis in dermoscopy images

    Science.gov (United States)

    Kharazmi, Pegah; Kalia, Sunil; Lui, Harvey; Wang, Z. Jane; Lee, Tim K.

    2018-02-01

    Basal cell carcinoma (BCC) is the most common type of skin cancer, which is highly damaging to the skin at its advanced stages and causes huge costs on the healthcare system. However, most types of BCC are easily curable if detected at early stage. Due to limited access to dermatologists and expert physicians, non-invasive computer-aided diagnosis is a viable option for skin cancer screening. A clinical biomarker of cancerous tumors is increased vascularization and excess blood flow. In this paper, we present a computer-aided technique to differentiate cancerous skin tumors from benign lesions based on vascular characteristics of the lesions. Dermoscopy image of the lesion is first decomposed using independent component analysis of the RGB channels to derive melanin and hemoglobin maps. A novel set of clinically inspired features and ratiometric measurements are then extracted from each map to characterize the vascular properties and blood content of the lesion. The feature set is then fed into a random forest classifier. Over a dataset of 664 skin lesions, the proposed method achieved an area under ROC curve of 0.832 in a 10-fold cross validation for differentiating basal cell carcinomas from benign lesions.

  9. Does computer-aided detection have a role in the arbitration of discordant double-reading opinions in a breast-screening programme?

    International Nuclear Information System (INIS)

    James, J.J.; Cornford, E.J.

    2009-01-01

    Aims: To investigate whether a computer-aided detection (CAD) system could act as an arbitrator of discordant double-reading opinions, replacing the need for an independent third film reader. Methods: The mammograms of the 240 women that underwent arbitration by an independent third reader were identified from the 16,629 women attending our screening centre between July 2003 and April 2004. Mammograms of the arbitration cases were digitized and analysed by a CAD system. To assess the ability of CAD to act as the arbitrator, the site of the CAD prompts was retrospectively compared to the site of any abnormality noted by the original film readers. If a CAD prompt was placed on a region marked by one of the film readers then the decision of CAD as the arbitrator was that the women should be recalled for further assessment. If no mark was placed then the region was considered low risk and the decision was not to recall. The decision of CAD as the arbitrator was retrospectively compared with the original recall decision of the independent third reader. Results: There were 21 cancer cases in the group of women undergoing arbitration, diagnosed both at the original screening episode and subsequently. The independent third reader recalled 15/18 (83%) of the cancers that corresponded with the arbitrated lesion. CAD as the arbitrator would have recalled 16/18 (89%) of the cancers that corresponded to the arbitrated lesion. CAD acting as the arbitrator would have resulted in a significant increase in normal women being recalled to assessment in the arbitration group (P < 0.001). The extra 50 recalls would have potentially increased the overall recall rate to assessment from 3.1 to 3.4%; a relative increase of 10%. Conclusions: The main effect of CAD acting as an arbitrator of discordant double-reading opinions is to increase the recall rate, significantly above what is found when arbitration is performed by an independent third reader. Using CAD as an arbitrator may be an

  10. Development of a computer-aided diagnostic scheme for detection of interval changes in successive whole-body bone scans

    International Nuclear Information System (INIS)

    Shiraishi, Junji; Li Qiang; Appelbaum, Daniel; Pu Yonglin; Doi, Kunio

    2007-01-01

    Bone scintigraphy is the most frequent examination among various diagnostic nuclear medicine procedures. It is a well-established imaging modality for the diagnosis of osseous metastasis and for monitoring osseous tumor response to chemotherapy and radiation therapy. Although the sensitivity of bone scan examinations for detection of bone abnormalities has been considered to be relatively high, it is time consuming to identify multiple lesions such as bone metastases of prostate and breast cancers. In addition, it is very difficult to detect subtle interval changes between two successive abnormal bone scans, because of variations in patient conditions, the accumulation of radioisotopes during each examination, and the image quality of gamma cameras. Therefore, we developed a new computer-aided diagnostic (CAD) scheme for the detection of interval changes in successive whole-body bone scans by use of a temporal subtraction image which was obtained with a nonlinear image-warping technique. We carried out 58 pairs of successive bone scans in which each scan included both posterior and anterior views. We determined 107 'gold-standard' interval changes among the 58 pairs based on the consensus of three radiologists. Our computerized scheme consisted of seven steps, i.e., initial image density normalization on each image, image matching for the paired images, temporal subtraction by use of the nonlinear image-warping technique, initial detection of interval changes by use of temporal-subtraction images, image feature extraction of candidates of interval changes, rule-based tests by use of 16 image features for removing some false positives, and display of the computer output for identified interval changes. One hundred seven gold standard interval changes included 71 hot lesions (uptake was increased compared with the previous scan, or there was new uptake in the current scan) and 36 cold lesions (uptake was decreased or disappeared) for anterior and posterior views. The

  11. Digital mammography: Signal-extraction strategies for computer-aided detection of microcalcifications

    International Nuclear Information System (INIS)

    Chan, H.P.; Doi, K.; Metz, C.E.; Vyborny, C.J.; Lam, K.L.; Schmidt, R.A.

    1987-01-01

    The authors found that the structured background of a mammogram can be removed effectively by either a difference-image technique (using a matched filter in combination with a median filter, a contrast-reversal filter, or a box-rim filter) or a visual response filter alone. Locally adaptive gray-level thresholding and region-growing techniques can then be employed to extract microcalcifications from the processed image. Signals are further distinguished from noise or artifacts by their size, contrast, and clustering properties. The authors studied the dependence of the detectability of microcalcifications on the various signal-extraction strategies. Potential application of the computer-aided system to mammography is assessed by its performance on clinical mammograms

  12. Computer-aided detection of pulmonary embolism: Influence on radiologists' detection performance with respect to vessel segments

    International Nuclear Information System (INIS)

    Das, Marco; Muehlenbruch, Georg; Helm, Anita; Guenther, Rolf W.; Wildberger, Joachim E.; Bakai, Annemarie; Salganicoff, Marcos; Liang, Jianming; Wolf, Matthias; Stanzel, Sven

    2008-01-01

    The purpose was to assess the sensitivity of a CAD software prototype for the detection of pulmonary embolism in MDCT chest examinations with regard to vessel level and to assess the influence on radiologists' detection performance. Forty-three patients with suspected PE were included in this retrospective study. MDCT chest examinations with a standard PE protocol were acquired at a 16-slice MDCT. All patient data were read by three radiologists (R1, R2, R3), and all thrombi were marked. A CAD prototype software was applied to all datasets, and each finding of the software was analyzed with regard to vessel level. The standard of reference was assessed in a consensus read. Sensitivity for the radiologists and CAD software was assessed. Thirty-three patients were positive for PE, with a total of 215 thrombi. The mean overall sensitivity for the CAD software alone was 83% (specificity, 80%). Radiologist sensitivity was 77% = R3, 82% = R2, and R1 = 87%. With the aid of the CAD software, sensitivities increased to 98% (R1), 93% (R2), and 92% (R3) (p<0.0001). CAD performance at the lobar level was 87%, at the segmental 90% and at the subsegmental 77%. With the use of CAD for PE, the detection performance of radiologists can be improved. (orig.)

  13. Integrated computer aided design simulation and manufacture

    OpenAIRE

    Diko, Faek

    1989-01-01

    Computer Aided Design (CAD) and Computer Aided Manufacture (CAM) have been investigated and developed since twenty years as standalone systems. A large number of very powerful but independent packages have been developed for Computer Aided Design,Aanlysis and Manufacture. However, in most cases these packages have poor facility for communicating with other packages. Recently attempts have been made to develop integrated CAD/CAM systems and many software companies a...

  14. Image-processing techniques used in the computer-aided detection of radiographic lesions in anatomic background

    International Nuclear Information System (INIS)

    Giger, M.L.; Doi, K.; MacMahon, H.; Yin, F.F.

    1988-01-01

    The authors developed feature-extraction techniques for use in the computer-aided detection of pulmonary nodules in digital chest images. Use of such a computer-aided detection scheme, which would alert radiologists to the locations of suspected lung nodules, is expected to reduce the number of false-negative diagnoses. False-negative diagnoses (i.e., misses) are a current problem in chest radiology with ''miss-rates'' as high as 30%. This may be due to the camouflaging effect of surrounding anatomic background on the nodule, or to the subjective and varying decision criteria used by radiologists

  15. Computer aided design (CAD) for electronics improvement of the nuclear channels of TRIGA Mark III reactor of the ININ

    International Nuclear Information System (INIS)

    Gonzalez M, J.L.; Rivero G, T.; Aguilar H, F.

    2007-01-01

    The 4 neutron measurement channels of the digital control console (CCD) of the TRIGA Mark III reactor (RTMIII) of the ININ, its were designed and built with the corresponding Quality Guarantee program, being achieved the one licensing to replace the old console. With the time they were carried out some changes to improve and to not solve some problems detected in the tests, verification and validation, requiring to modify the circuits originally designed. In this work the corrective actions carried out to eliminate the Non Conformity generated by these problems, being mentioned the advantages of using modern tools, as the software applied to the Attended Engineering by Computer, and those obtained results are presented. (Author)

  16. The utility of computer-aided-detection for the assessment of pulmonary arterial filling defects at CT angiography

    International Nuclear Information System (INIS)

    Roberts, H.C.; Walsham, A.; Colak, E.; Kashani, H.; Mongiardi, C.; Patsios, D.

    2007-01-01

    The purpose of this study is to validate a computer assisted detection (CAD) system for the detection of pulmonary intra-arterial filling defects and assess its utility for radiology readers of different levels of experience. Methods: 100 contrast-enhanced computed tomography pulmonary angiograms (CTPAs) performed to rule out pulmonary embolism (PE) were retrospectively analyzed; all were previously read by the chest radiologist on service and were re-assessed by a chest radiologist for the presence and location of PE. CTPAs were analyzed using the second generation CAD software pulmonary artery Patency Exam (PE trademark) tool, used with the ImageChecker registered CT (version 2.1 R2 Technology Inc., Santa Clara, CA). Each CAD mark was assigned one of the following interpretations: true positive, TP: intra-arterial filling defect found by CAD and the radiologist; false positive, FP: CAD mark that was not a filling defect; false negative, FN: filling defect found by the radiologist, but not by CAD. CAD performance was quantified on a per case basis; if CAD did not mark a study negative for PE, this was defined as true negative (TN). If CAD yielded FP marks only in a study positive for PE, this was counted as a FN case. All CTPAs were interpreted by four readers of different levels of experience, both without and with CAD. They recorded the reading time, the presence and location of PE, and the confidence in their diagnosis (1 = least, 2 moderately, 3 = very confident). Results: 21 cases were positive for PE. CAD showed marks in all 21 cases, but in three cases, all were FP marks (3 FN cases, 18 TP cases). Of the 79 exams negative for PE, 16 had no CAD marks (16 TN cases), 63 had at least one CAD mark (63 FP cases). On a case-basis, CAD sensitivity was 86%, negative predictive value was 84%, specificity 20%, positive predictive value (PPV) 22%. In the 21 positive cases, 93 filling defects were identified, of which 64 were correctly marked by CAD (sensitivity 69

  17. Three-Dimensional Computer-Aided Detection of Microcalcification Clusters in Digital Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Ji-wook Jeong

    2016-01-01

    Full Text Available We propose computer-aided detection (CADe algorithm for microcalcification (MC clusters in reconstructed digital breast tomosynthesis (DBT images. The algorithm consists of prescreening, MC detection, clustering, and false-positive (FP reduction steps. The DBT images containing the MC-like objects were enhanced by a multiscale Hessian-based three-dimensional (3D objectness response function and a connected-component segmentation method was applied to extract the cluster seed objects as potential clustering centers of MCs. Secondly, a signal-to-noise ratio (SNR enhanced image was also generated to detect the individual MC candidates and prescreen the MC-like objects. Each cluster seed candidate was prescreened by counting neighboring individual MC candidates nearby the cluster seed object according to several microcalcification clustering criteria. As a second step, we introduced bounding boxes for the accepted seed candidate, clustered all the overlapping cubes, and examined. After the FP reduction step, the average number of FPs per case was estimated to be 2.47 per DBT volume with a sensitivity of 83.3%.

  18. Deep learning of contrast-coated serrated polyps for computer-aided detection in CT colonography

    Science.gov (United States)

    Näppi, Janne J.; Pickhardt, Perry; Kim, David H.; Hironaka, Toru; Yoshida, Hiroyuki

    2017-03-01

    Serrated polyps were previously believed to be benign lesions with no cancer potential. However, recent studies have revealed a novel molecular pathway where also serrated polyps can develop into colorectal cancer. CT colonography (CTC) can detect serrated polyps using the radiomic biomarker of contrast coating, but this requires expertise from the reader and current computer-aided detection (CADe) systems have not been designed to detect the contrast coating. The purpose of this study was to develop a novel CADe method that makes use of deep learning to detect serrated polyps based on their contrast-coating biomarker in CTC. In the method, volumetric shape-based features are used to detect polyp sites over soft-tissue and fecal-tagging surfaces of the colon. The detected sites are imaged using multi-angular 2D image patches. A deep convolutional neural network (DCNN) is used to review the image patches for the presence of polyps. The DCNN-based polyp-likelihood estimates are merged into an aggregate likelihood index where highest values indicate the presence of a polyp. For pilot evaluation, the proposed DCNN-CADe method was evaluated with a 10-fold cross-validation scheme using 101 colonoscopy-confirmed cases with 144 biopsy-confirmed serrated polyps from a CTC screening program, where the patients had been prepared for CTC with saline laxative and fecal tagging by barium and iodine-based diatrizoate. The average per-polyp sensitivity for serrated polyps >=6 mm in size was 93+/-7% at 0:8+/-1:8 false positives per patient on average. The detection accuracy was substantially higher that of a conventional CADe system. Our results indicate that serrated polyps can be detected automatically at high accuracy in CTC.

  19. Computer-aided detection of artificial pulmonary nodules using an ex vivo lung phantom: influence of exposure parameters and iterative reconstruction.

    Science.gov (United States)

    Wielpütz, Mark O; Wroblewski, Jacek; Lederlin, Mathieu; Dinkel, Julien; Eichinger, Monika; Koenigkam-Santos, M; Biederer, Jürgen; Kauczor, Hans-Ulrich; Puderbach, Michael U; Jobst, Bertram J

    2015-05-01

    To evaluate the influence of exposure parameters and raw-data based iterative reconstruction (IR) on the performance of computer-aided detection (CAD) of pulmonary nodules on chest multidetector computed tomography (MDCT). Seven porcine lung explants were inflated in a dedicated ex vivo phantom shell and prepared with n=162 artificial nodules of a clinically relevant volume and maximum diameter (46-1063 μl, and 6.2-21.5 mm). n=118 nodules were solid and n=44 part-solid. MDCT was performed with different combinations of 120 and 80 kV with 120, 60, 30 and 12 mA*s, and reconstructed with both filtered back projection (FBP) and IR. Subsequently, 16 datasets per lung were subjected to dedicated CAD software. The rate of true positive, false negative and false positive CAD marks was measured for each reconstruction. The rate of true positive findings ranged between 88.9-91.4% for FBP and 88.3-90.1% for IR (n.s.) with most exposure settings, but was significantly lower with the combination of 80 kV and 12 mA*s (80.9% and 81.5%, respectively, pvolumes 300 μl (p<0.05). Similarly, it was significantly lower for diameters <12 mm compared to ≥12 mm (p<0.05). The rate of true positives for solid and part-solid nodules was similar. Nodule CAD on chest MDCT is robust over a wide range of exposure settings. Noise reduction by IR is not detrimental for CAD, and may be used to improve image quality in the setting of low-dose MDCT for lung cancer screening. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Computer aided detection in prostate cancer diagnostics: A promising alternative to biopsy? A retrospective study from 104 lesions with histological ground truth.

    Directory of Open Access Journals (Sweden)

    Anika Thon

    Full Text Available Prostate cancer (PCa diagnosis by means of multiparametric magnetic resonance imaging (mpMRI is a current challenge for the development of computer-aided detection (CAD tools. An innovative CAD-software (Watson Elementary™ was proposed to achieve high sensitivity and specificity, as well as to allege a correlate to Gleason grade.To assess the performance of Watson Elementary™ in automated PCa diagnosis in our hospital´s database of MRI-guided prostate biopsies.The evaluation was retrospective for 104 lesions (47 PCa, 57 benign from 79, 64.61±6.64 year old patients using 3T T2-weighted imaging, Apparent Diffusion Coefficient (ADC maps and dynamic contrast enhancement series. Watson Elementary™ utilizes signal intensity, diffusion properties and kinetic profile to compute a proportional Gleason grade predictor, termed Malignancy Attention Index (MAI. The analysis focused on (i the CAD sensitivity and specificity to classify suspect lesions and (ii the MAI correlation with the histopathological ground truth.The software revealed a sensitivity of 46.80% for PCa classification. The specificity for PCa was found to be 75.43% with a positive predictive value of 61.11%, a negative predictive value of 63.23% and a false discovery rate of 38.89%. CAD classified PCa and benign lesions with equal probability (P 0.06, χ2 test. Accordingly, receiver operating characteristic analysis suggests a poor predictive value for MAI with an area under curve of 0.65 (P 0.02, which is not superior to the performance of board certified observers. Moreover, MAI revealed no significant correlation with Gleason grade (P 0.60, Pearson´s correlation.The tested CAD software for mpMRI analysis was a weak PCa biomarker in this dataset. Targeted prostate biopsy and histology remains the gold standard for prostate cancer diagnosis.

  1. Improving computer-aided detection assistance in breast cancer screening by removal of obviously false-positive findings

    NARCIS (Netherlands)

    Mordang, Jan-Jurre; Gubern-Merida, Albert; Bria, Alessandro; Tortorella, Francesco; den Heeten, Gerard; Karssemeijer, Nico

    2017-01-01

    Purpose: Computer-aided detection (CADe) systems for mammography screening still mark many false positives. This can cause radiologists to lose confidence in CADe, especially when many false positives are obviously not suspicious to them. In this study, we focus on obvious false positives generated

  2. Improving computer-aided detection assistance in breast cancer screening by removal of obviously false-positive findings

    NARCIS (Netherlands)

    Mordang, J.J.; Gubern Merida, A.; Bria, A.; Tortorella, F.; Heeten, G.; Karssemeijer, N.

    2017-01-01

    PURPOSE: Computer-aided detection (CADe) systems for mammography screening still mark many false positives. This can cause radiologists to lose confidence in CADe, especially when many false positives are obviously not suspicious to them. In this study, we focus on obvious false positives generated

  3. Interpretation Time Using a Concurrent-Read Computer-Aided Detection System for Automated Breast Ultrasound in Breast Cancer Screening of Women With Dense Breast Tissue.

    Science.gov (United States)

    Jiang, Yulei; Inciardi, Marc F; Edwards, Alexandra V; Papaioannou, John

    2018-05-24

    The purpose of this study was to compare diagnostic accuracy and interpretation time of screening automated breast ultrasound (ABUS) for women with dense breast tissue without and with use of a recently U.S. Food and Drug Administration-approved computer-aided detection (CAD) system for concurrent read. In a retrospective observer performance study, 18 radiologists interpreted a cancer-enriched set (i.e., cancer prevalence higher than in the original screening cohort) of 185 screening ABUS studies (52 with and 133 without breast cancer). These studies were from a large cohort of ABUS screened patients interpreted as BI-RADS density C or D. Each reader interpreted each case twice in a counterbalanced study, once without the CAD system and once with it, separated by 4 weeks. For each case, each reader identified abnormal findings and reported BI-RADS assessment category and level of suspicion for breast cancer. Interpretation time was recorded. Level of suspicion data were compared to evaluate diagnostic accuracy by means of the Dorfman-Berbaum-Metz method of jackknife with ANOVA ROC analysis. Interpretation times were compared by ANOVA. The ROC AUC was 0.848 with the CAD system, compared with 0.828 without it, for a difference of 0.020 (95% CI, -0.011 to 0.051) and was statistically noninferior to the AUC without the CAD system with respect to a margin of -0.05 (p = 0.000086). The mean interpretation time was 3 minutes 33 seconds per case without the CAD system and 2 minutes 24 seconds with it, for a difference of 1 minute 9 seconds saved (95% CI, 44-93 seconds; p = 0.000014), or a reduction in interpretation time to 67% of the time without the CAD system. Use of the concurrent-read CAD system for interpretation of screening ABUS studies of women with dense breast tissue who do not have symptoms is expected to make interpretation significantly faster and produce noninferior diagnostic accuracy compared with interpretation without the CAD system.

  4. Computer-aided detection of bladder wall thickening in CT urography (CTU)

    Science.gov (United States)

    Cha, Kenny H.; Hadjiiski, Lubomir M.; Chan, Heang-Ping; Caoili, Elaine M.; Cohan, Richard H.; Weizer, Alon Z.; Gordon, Marshall N.; Samala, Ravi K.

    2018-02-01

    We are developing a computer-aided detection system for bladder cancer in CT urography (CTU). Bladder wall thickening is a manifestation of bladder cancer and its detection is more challenging than the detection of bladder masses. We first segmented the inner and outer bladder walls using our method that combined deep-learning convolutional neural network with level sets. The non-contrast-enhanced region was separated from the contrast-enhanced region with a maximum-intensity-projection-based method. The non-contrast region was smoothed and gray level threshold was applied to the contrast and non-contrast regions separately to extract the bladder wall and potential lesions. The bladder wall was transformed into a straightened thickness profile, which was analyzed to identify regions of wall thickening candidates. Volume-based features of the wall thickening candidates were analyzed with linear discriminant analysis (LDA) to differentiate bladder wall thickenings from false positives. A data set of 112 patients, 87 with wall thickening and 25 with normal bladders, was collected retrospectively with IRB approval, and split into independent training and test sets. Of the 57 training cases, 44 had bladder wall thickening and 13 were normal. Of the 55 test cases, 43 had wall thickening and 12 were normal. The LDA classifier was trained with the training set and evaluated with the test set. FROC analysis showed that the system achieved sensitivities of 93.2% and 88.4% for the training and test sets, respectively, at 0.5 FPs/case.

  5. Computer-aided detection system for lung cancer in computed tomography scans: Review and future prospects

    Science.gov (United States)

    2014-01-01

    Introduction The goal of this paper is to present a critical review of major Computer-Aided Detection systems (CADe) for lung cancer in order to identify challenges for future research. CADe systems must meet the following requirements: improve the performance of radiologists providing high sensitivity in the diagnosis, a low number of false positives (FP), have high processing speed, present high level of automation, low cost (of implementation, training, support and maintenance), the ability to detect different types and shapes of nodules, and software security assurance. Methods The relevant literature related to “CADe for lung cancer” was obtained from PubMed, IEEEXplore and Science Direct database. Articles published from 2009 to 2013, and some articles previously published, were used. A systemic analysis was made on these articles and the results were summarized. Discussion Based on literature search, it was observed that many if not all systems described in this survey have the potential to be important in clinical practice. However, no significant improvement was observed in sensitivity, number of false positives, level of automation and ability to detect different types and shapes of nodules in the studied period. Challenges were presented for future research. Conclusions Further research is needed to improve existing systems and propose new solutions. For this, we believe that collaborative efforts through the creation of open source software communities are necessary to develop a CADe system with all the requirements mentioned and with a short development cycle. In addition, future CADe systems should improve the level of automation, through integration with picture archiving and communication systems (PACS) and the electronic record of the patient, decrease the number of false positives, measure the evolution of tumors, evaluate the evolution of the oncological treatment, and its possible prognosis. PMID:24713067

  6. Large scale deep learning for computer aided detection of mammographic lesions.

    Science.gov (United States)

    Kooi, Thijs; Litjens, Geert; van Ginneken, Bram; Gubern-Mérida, Albert; Sánchez, Clara I; Mann, Ritse; den Heeten, Ard; Karssemeijer, Nico

    2017-01-01

    Recent advances in machine learning yielded new techniques to train deep neural networks, which resulted in highly successful applications in many pattern recognition tasks such as object detection and speech recognition. In this paper we provide a head-to-head comparison between a state-of-the art in mammography CAD system, relying on a manually designed feature set and a Convolutional Neural Network (CNN), aiming for a system that can ultimately read mammograms independently. Both systems are trained on a large data set of around 45,000 images and results show the CNN outperforms the traditional CAD system at low sensitivity and performs comparable at high sensitivity. We subsequently investigate to what extent features such as location and patient information and commonly used manual features can still complement the network and see improvements at high specificity over the CNN especially with location and context features, which contain information not available to the CNN. Additionally, a reader study was performed, where the network was compared to certified screening radiologists on a patch level and we found no significant difference between the network and the readers. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Max-AUC feature selection in computer-aided detection of polyps in CT colonography.

    Science.gov (United States)

    Xu, Jian-Wu; Suzuki, Kenji

    2014-03-01

    We propose a feature selection method based on a sequential forward floating selection (SFFS) procedure to improve the performance of a classifier in computerized detection of polyps in CT colonography (CTC). The feature selection method is coupled with a nonlinear support vector machine (SVM) classifier. Unlike the conventional linear method based on Wilks' lambda, the proposed method selected the most relevant features that would maximize the area under the receiver operating characteristic curve (AUC), which directly maximizes classification performance, evaluated based on AUC value, in the computer-aided detection (CADe) scheme. We presented two variants of the proposed method with different stopping criteria used in the SFFS procedure. The first variant searched all feature combinations allowed in the SFFS procedure and selected the subsets that maximize the AUC values. The second variant performed a statistical test at each step during the SFFS procedure, and it was terminated if the increase in the AUC value was not statistically significant. The advantage of the second variant is its lower computational cost. To test the performance of the proposed method, we compared it against the popular stepwise feature selection method based on Wilks' lambda for a colonic-polyp database (25 polyps and 2624 nonpolyps). We extracted 75 morphologic, gray-level-based, and texture features from the segmented lesion candidate regions. The two variants of the proposed feature selection method chose 29 and 7 features, respectively. Two SVM classifiers trained with these selected features yielded a 96% by-polyp sensitivity at false-positive (FP) rates of 4.1 and 6.5 per patient, respectively. Experiments showed a significant improvement in the performance of the classifier with the proposed feature selection method over that with the popular stepwise feature selection based on Wilks' lambda that yielded 18.0 FPs per patient at the same sensitivity level.

  8. Selection of an optimal neural network architecture for computer-aided detection of microcalcifications - Comparison of automated optimization techniques

    International Nuclear Information System (INIS)

    Gurcan, Metin N.; Sahiner, Berkman; Chan Heangping; Hadjiiski, Lubomir; Petrick, Nicholas

    2001-01-01

    Many computer-aided diagnosis (CAD) systems use neural networks (NNs) for either detection or classification of abnormalities. Currently, most NNs are 'optimized' by manual search in a very limited parameter space. In this work, we evaluated the use of automated optimization methods for selecting an optimal convolution neural network (CNN) architecture. Three automated methods, the steepest descent (SD), the simulated annealing (SA), and the genetic algorithm (GA), were compared. We used as an example the CNN that classifies true and false microcalcifications detected on digitized mammograms by a prescreening algorithm. Four parameters of the CNN architecture were considered for optimization, the numbers of node groups and the filter kernel sizes in the first and second hidden layers, resulting in a search space of 432 possible architectures. The area A z under the receiver operating characteristic (ROC) curve was used to design a cost function. The SA experiments were conducted with four different annealing schedules. Three different parent selection methods were compared for the GA experiments. An available data set was split into two groups with approximately equal number of samples. By using the two groups alternately for training and testing, two different cost surfaces were evaluated. For the first cost surface, the SD method was trapped in a local minimum 91% (392/432) of the time. The SA using the Boltzman schedule selected the best architecture after evaluating, on average, 167 architectures. The GA achieved its best performance with linearly scaled roulette-wheel parent selection; however, it evaluated 391 different architectures, on average, to find the best one. The second cost surface contained no local minimum. For this surface, a simple SD algorithm could quickly find the global minimum, but the SA with the very fast reannealing schedule was still the most efficient. The same SA scheme, however, was trapped in a local minimum on the first cost

  9. Computer-Aided Design in Further Education.

    Science.gov (United States)

    Ingham, Peter, Ed.

    This publication updates the 1982 occasional paper that was intended to foster staff awareness and assist colleges in Great Britain considering the use of computer-aided design (CAD) material in engineering courses. The paper begins by defining CAD and its place in the Integrated Business System with a brief discussion of the effect of CAD on the…

  10. Integrated computer-aided design in automotive development development processes, geometric fundamentals, methods of CAD, knowledge-based engineering data management

    CERN Document Server

    Mario, Hirz; Gfrerrer, Anton; Lang, Johann

    2013-01-01

    The automotive industry faces constant pressure to reduce development costs and time while still increasing vehicle quality. To meet this challenge, engineers and researchers in both science and industry are developing effective strategies and flexible tools by enhancing and further integrating powerful, computer-aided design technology. This book provides a valuable overview of the development tools and methods of today and tomorrow. It is targeted not only towards professional project and design engineers, but also to students and to anyone who is interested in state-of-the-art computer-aided development. The book begins with an overview of automotive development processes and the principles of virtual product development. Focusing on computer-aided design, a comprehensive outline of the fundamentals of geometry representation provides a deeper insight into the mathematical techniques used to describe and model geometrical elements. The book then explores the link between the demands of integrated design pr...

  11. Massive-training artificial neural network (MTANN) for reduction of false positives in computer-aided detection of polyps: Suppression of rectal tubes

    International Nuclear Information System (INIS)

    Suzuki, Kenji; Yoshida, Hiroyuki; Naeppi, Janne; Dachman, Abraham H.

    2006-01-01

    One of the limitations of the current computer-aided detection (CAD) of polyps in CT colonography (CTC) is a relatively large number of false-positive (FP) detections. Rectal tubes (RTs) are one of the typical sources of FPs because a portion of a RT, especially a portion of a bulbous tip, often exhibits a cap-like shape that closely mimics the appearance of a small polyp. Radiologists can easily recognize and dismiss RT-induced FPs; thus, they may lose their confidence in CAD as an effective tool if the CAD scheme generates such ''obvious'' FPs due to RTs consistently. In addition, RT-induced FPs may distract radiologists from less common true positives in the rectum. Therefore, removal RT-induced FPs as well as other types of FPs is desirable while maintaining a high sensitivity in the detection of polyps. We developed a three-dimensional (3D) massive-training artificial neural network (MTANN) for distinction between polyps and RTs in 3D CTC volumetric data. The 3D MTANN is a supervised volume-processing technique which is trained with input CTC volumes and the corresponding ''teaching'' volumes. The teaching volume for a polyp contains a 3D Gaussian distribution, and that for a RT contains zeros for enhancement of polyps and suppression of RTs, respectively. For distinction between polyps and nonpolyps including RTs, a 3D scoring method based on a 3D Gaussian weighting function is applied to the output of the trained 3D MTANN. Our database consisted of CTC examinations of 73 patients, scanned in both supine and prone positions (146 CTC data sets in total), with optical colonoscopy as a reference standard for the presence of polyps. Fifteen patients had 28 polyps, 15 of which were 5-9 mm and 13 were 10-25 mm in size. These CTC cases were subjected to our previously reported CAD scheme that included centerline-based segmentation of the colon, shape-based detection of polyps, and reduction of FPs by use of a Bayesian neural network based on geometric and texture

  12. Implementation of combined SVM-algorithm and computer-aided perception feedback for pulmonary nodule detection

    Science.gov (United States)

    Pietrzyk, Mariusz W.; Rannou, Didier; Brennan, Patrick C.

    2012-02-01

    This pilot study examines the effect of a novel decision support system in medical image interpretation. This system is based on combining image spatial frequency properties and eye-tracking data in order to recognize over and under calling errors. Thus, before it can be implemented as a detection aided schema, training is required during which SVMbased algorithm learns to recognize FP from all reported outcomes, and, FN from all unreported prolonged dwelled regions. Eight radiologists inspected 50 PA chest radiographs with the specific task of identifying lung nodules. Twentyfive cases contained CT proven subtle malignant lesions (5-20mm), but prevalence was not known by the subjects, who took part in two sequential reading sessions, the second, without and with support system feedback. MCMR ROC DBM and JAFROC analyses were conducted and demonstrated significantly higher scores following feedback with p values of 0.04, and 0.03 respectively, highlighting significant improvements in radiology performance once feedback was used. This positive effect on radiologists' performance might have important implications for future CAD-system development.

  13. Computer-aided diagnosis and volumetry of pulmonary nodules: current concepts and future perspectives

    International Nuclear Information System (INIS)

    Marten, K.; Rummeny, E.J.; Engelke, C.

    2005-01-01

    For computer-aided detection (CAD) and volumetry of small pulmonary nodules, a number of algorithms have been developed for multislice CT data sets in recent years, with the goal of improving the diagnostic work-up and the follow-up of findings. Recent data show that the detection of small lesions may improve with CAD, suggesting that especially experienced readers may benefit from using CAD systems. This has lead to the recommendation of CAD as a replacement of the second reader in clinical practice. Furthermore, computer-aided volumetry of pulmonary nodules allows a precise determination of nodular growth rates as a prerequisite for a better classification of nodules as benign or malignant. In this article, we review recent developments of CAD and volumetry tools for pulmonary nodules, and address open questions regarding the use of these software tools in clinical routine. (orig.)

  14. Development of computer-aided diagnosis systems in radiology

    International Nuclear Information System (INIS)

    Higashida, Yoshiharu; Arimura, Hidetaka; Kumazawa, Seiji; Morishita, Junji; Sakai, Shuji

    2006-01-01

    Computer-aided diagnosis (CAD) is a practice done by medical doctors based on computer image analysis as the second opinion, and CAD studies have been government-adopted projects. CAD is already on popular practice in the cancers of the breast by mammography, lung by flat plate and CT images, and large bowel by CT colonoscopy. This paper describes four examples of authors' actual CAD investigations. First, the temporal subtraction image analysis by CAD is for the detection of abnormality in the chest by radiographs taken at different times. Examples are shown in cases of interstitial pneumonia and lung cancer out of 34 patients with diffuse lung diseases. Second, development of CAD system is recorded for detection of aneurysm by the brain MR angiography (MRA). Third is the CAD detection of fascicles in cerebral white matters by the diffuse tensor MRI, which will help the surgery for brain tumors. Final is an automated patient recognition based on an image-matching technique using previous chest radiographs in the picture archiving and communication systems. This is on the radiograph giving biological fingerprints of the patients. CAD will be applied in a wider field of medicare not only in imaging technology. (T.I)

  15. Simultaneous detection and classification of breast masses in digital mammograms via a deep learning YOLO-based CAD system.

    Science.gov (United States)

    Al-Masni, Mohammed A; Al-Antari, Mugahed A; Park, Jeong-Min; Gi, Geon; Kim, Tae-Yeon; Rivera, Patricio; Valarezo, Edwin; Choi, Mun-Taek; Han, Seung-Moo; Kim, Tae-Seong

    2018-04-01

    Automatic detection and classification of the masses in mammograms are still a big challenge and play a crucial role to assist radiologists for accurate diagnosis. In this paper, we propose a novel Computer-Aided Diagnosis (CAD) system based on one of the regional deep learning techniques, a ROI-based Convolutional Neural Network (CNN) which is called You Only Look Once (YOLO). Although most previous studies only deal with classification of masses, our proposed YOLO-based CAD system can handle detection and classification simultaneously in one framework. The proposed CAD system contains four main stages: preprocessing of mammograms, feature extraction utilizing deep convolutional networks, mass detection with confidence, and finally mass classification using Fully Connected Neural Networks (FC-NNs). In this study, we utilized original 600 mammograms from Digital Database for Screening Mammography (DDSM) and their augmented mammograms of 2,400 with the information of the masses and their types in training and testing our CAD. The trained YOLO-based CAD system detects the masses and then classifies their types into benign or malignant. Our results with five-fold cross validation tests show that the proposed CAD system detects the mass location with an overall accuracy of 99.7%. The system also distinguishes between benign and malignant lesions with an overall accuracy of 97%. Our proposed system even works on some challenging breast cancer cases where the masses exist over the pectoral muscles or dense regions. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Computer-Aided Diagnosis Systems for Brain Diseases in Magnetic Resonance Images

    Directory of Open Access Journals (Sweden)

    Yasuo Yamashita

    2009-07-01

    Full Text Available This paper reviews the basics and recent researches of computer-aided diagnosis (CAD systems for assisting neuroradiologists in detection of brain diseases, e.g., asymptomatic unruptured aneurysms, Alzheimer's disease, vascular dementia, and multiple sclerosis (MS, in magnetic resonance (MR images. The CAD systems consist of image feature extraction based on image processing techniques and machine learning classifiers such as linear discriminant analysis, artificial neural networks, and support vector machines. We introduce useful examples of the CAD systems in the neuroradiology, and conclude with possibilities in the future of the CAD systems for brain diseases in MR images.

  17. Implications of unchanged detection criteria with CAD as second reader of mammograms

    International Nuclear Information System (INIS)

    Bornefalk, Hans

    2006-01-01

    In this paper we address the use of computer-aided detection (CAD) systems as second readers in mammography. The approach is based on Bayesian decision theory and its implication for the choice of optimal operating points. The choice of a certain operating point along an ROC curve corresponds to a particular tradeoff between false positives and missed cancers. By minimizing a total risk function given this tradeoff, we determine optimal decision thresholds for the radiologist and CAD system when CAD is used as a second reader. We show that under very general circumstances, the performance of the sequential system is improved if the decision threshold of the latent human decision variable is increased compared to what it would have been in the absence of the CAD system. This means that an initial stricter decision criterion should be applied by the radiologist when CAD is used as a second reader than otherwise. First and foremost, the results in this paper should be interpreted qualitatively, but an attempt is made at quantifying the effect by tuning the model to a prospective study evaluating the use of CAD as a second reader. By making some necessary and plausible assumptions, we are able to estimate the effect of the resulting suboptimal operating point. In this study of 12 860 women, we estimate that a 15% reduction in callbacks for masses could have been achieved with only about a 1.5% relative decrease in sensitivity compared to that without using a stricter initial criterion by the radiologist. For microcalcifications the corresponding values are 7% and 0.2%

  18. Phased searching with NEAT in a time-scaled framework: experiments on a computer-aided detection system for lung nodules.

    Science.gov (United States)

    Tan, Maxine; Deklerck, Rudi; Cornelis, Jan; Jansen, Bart

    2013-11-01

    In the field of computer-aided detection (CAD) systems for lung nodules in computed tomography (CT) scans, many image features are presented and many artificial neural network (ANN) classifiers with various structural topologies are analyzed; frequently, the classifier topologies are selected by trial-and-error experiments. To avoid these trial and error approaches, we present a novel classifier that evolves ANNs using genetic algorithms, called "Phased Searching with NEAT in a Time or Generation-Scaled Framework", integrating feature selection with the classification task. We analyzed our method's performance on 360 CT scans from the public Lung Image Database Consortium database. We compare our method's performance with other more-established classifiers, namely regular NEAT, Feature-Deselective NEAT (FD-NEAT), fixed-topology ANNs, and support vector machines (SVMs) using ten-fold cross-validation experiments of all 360 scans. The results show that the proposed "Phased Searching" method performs better and faster than regular NEAT, better than FD-NEAT, and achieves sensitivities at 3 and 4 false positives (FP) per scan that are comparable with the fixed-topology ANN and SVM classifiers, but with fewer input features. It achieves a detection sensitivity of 83.0±9.7% with an average of 4FP/scan, for nodules with a diameter greater than or equal to 3mm. It also evolves networks with shorter evolution times and with lower complexities than regular NEAT (p=0.026 and pNEAT and by our approach shows that our approach searches for good solutions in lower dimensional search spaces, and evolves networks without superfluous structure. We have presented a novel approach that combines feature selection with the evolution of ANN topology and weights. Compared with the original threshold-based Phased Searching method of Green, our method requires fewer parameters and converges to the optimal network complexity required for the classification task at hand. The results of the

  19. Computer-aided diagnosis of colonic polyp by CT colonography

    International Nuclear Information System (INIS)

    Yoshida, Hiroyuki

    2007-01-01

    The outcome of National CT Colonography Trial, by American College of Radiology Imaging Network, 2006 (www.acrin.org/6664 protocol), possibly leads to the introduction of colorectal cancer screening in the US because CT colonography (CTCG) has been approved in the health insurance system. This paper describes the outline of computer-aided diagnosis (CAD) of colonic polyp by CTCG, its polyp detectability and future aspects. CTCG essentially derives from the virtual, abdominal 3D CT images and gives as many as about 500 images/patient, in the reading of which CAD support the expert. CAD technology in CTCG is said to have been essentially established in the first half of 2000s, which involves the cleansing of fecal tagging effect, extraction of the colonal wall from the image, detection of suspicious polyp, reduction of false-positive findings and displaying of the detected polyp. The detectability is thought to be at comparable level to expert's. The last displaying is done on the user-interface like Colon CAD Workstation. More efficient expert's reading with CAD, imaging without previous gut cleansing, detection of the flat lesion and further reduction of false-positive are the forthcoming tasks in clinical practice. Significance of CTCG is becoming in realization and its usage with CAD is thought to be more popular in Japan. (R.T.)

  20. Computer-aided detection of renal calculi from noncontrast CT images using TV-flow and MSER features

    Science.gov (United States)

    Liu, Jianfei; Wang, Shijun; Turkbey, Evrim B.; Linguraru, Marius George; Yao, Jianhua; Summers, Ronald M.

    2015-01-01

    Purpose: Renal calculi are common extracolonic incidental findings on computed tomographic colonography (CTC). This work aims to develop a fully automated computer-aided diagnosis system to accurately detect renal calculi on CTC images. Methods: The authors developed a total variation (TV) flow method to reduce image noise within the kidneys while maintaining the characteristic appearance of renal calculi. Maximally stable extremal region (MSER) features were then calculated to robustly identify calculi candidates. Finally, the authors computed texture and shape features that were imported to support vector machines for calculus classification. The method was validated on a dataset of 192 patients and compared to a baseline approach that detects calculi by thresholding. The authors also compared their method with the detection approaches using anisotropic diffusion and nonsmoothing. Results: At a false positive rate of 8 per patient, the sensitivities of the new method and the baseline thresholding approach were 69% and 35% (p < 1e − 3) on all calculi from 1 to 433 mm3 in the testing dataset. The sensitivities of the detection methods using anisotropic diffusion and nonsmoothing were 36% and 0%, respectively. The sensitivity of the new method increased to 90% if only larger and more clinically relevant calculi were considered. Conclusions: Experimental results demonstrated that TV-flow and MSER features are efficient means to robustly and accurately detect renal calculi on low-dose, high noise CTC images. Thus, the proposed method can potentially improve diagnosis. PMID:25563255

  1. Computer aided detection of suspicious regions on digital mammograms : rapid segmentation and feature extraction

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, C; Giacomini, M; Sacile, R [DIST - Department of Communication Computer and System Sciences, University of Genova, Via Opera Pia 13, 16145 Genova (Italy); Rosselli Del Turco, M [Centro per lo studio e la prevenzione oncologica, Firenze (Italy)

    1999-12-31

    A method is presented for rapid detection of suspicious regions which consists of two steps. The first step is segmentation based on texture analysis consisting of : histogram equalization, Laws filtering for texture analysis, Gaussian blur and median filtering to enhance differences between tissues in different respects, histogram thresholding to obtain a binary image, logical masking in order to detect regions to be discarded from the analysis, edge detection. This method has been tested on 60 images, obtaining 93% successful detection of suspicious regions. (authors) 4 refs, 9 figs, 1 tabs.

  2. Feasibility Study of a Generalized Framework for Developing Computer-Aided Detection Systems-a New Paradigm.

    Science.gov (United States)

    Nemoto, Mitsutaka; Hayashi, Naoto; Hanaoka, Shouhei; Nomura, Yukihiro; Miki, Soichiro; Yoshikawa, Takeharu

    2017-10-01

    We propose a generalized framework for developing computer-aided detection (CADe) systems whose characteristics depend only on those of the training dataset. The purpose of this study is to show the feasibility of the framework. Two different CADe systems were experimentally developed by a prototype of the framework, but with different training datasets. The CADe systems include four components; preprocessing, candidate area extraction, candidate detection, and candidate classification. Four pretrained algorithms with dedicated optimization/setting methods corresponding to the respective components were prepared in advance. The pretrained algorithms were sequentially trained in the order of processing of the components. In this study, two different datasets, brain MRA with cerebral aneurysms and chest CT with lung nodules, were collected to develop two different types of CADe systems in the framework. The performances of the developed CADe systems were evaluated by threefold cross-validation. The CADe systems for detecting cerebral aneurysms in brain MRAs and for detecting lung nodules in chest CTs were successfully developed using the respective datasets. The framework was shown to be feasible by the successful development of the two different types of CADe systems. The feasibility of this framework shows promise for a new paradigm in the development of CADe systems: development of CADe systems without any lesion specific algorithm designing.

  3. [Accuracy of computer aided measurement for detecting dental proximal caries lesions in images of cone-beam computed tomography].

    Science.gov (United States)

    Zhang, Z L; Li, J P; Li, G; Ma, X C

    2017-02-09

    Objective: To establish and validate a computer program used to aid the detection of dental proximal caries in the images cone beam computed tomography (CBCT) images. Methods: According to the characteristics of caries lesions in X-ray images, a computer aided detection program for proximal caries was established with Matlab and Visual C++. The whole process for caries lesion detection included image import and preprocessing, measuring average gray value of air area, choosing region of interest and calculating gray value, defining the caries areas. The program was used to examine 90 proximal surfaces from 45 extracted human teeth collected from Peking University School and Hospital of Stomatology. The teeth were then scanned with a CBCT scanner (Promax 3D). The proximal surfaces of the teeth were respectively detected by caries detection program and scored by human observer for the extent of lesions with 6-level-scale. With histologic examination serving as the reference standard, the caries detection program and the human observer performances were assessed with receiver operating characteristic (ROC) curves. Student t -test was used to analyze the areas under the ROC curves (AUC) for the differences between caries detection program and human observer. Spearman correlation coefficient was used to analyze the detection accuracy of caries depth. Results: For the diagnosis of proximal caries in CBCT images, the AUC values of human observers and caries detection program were 0.632 and 0.703, respectively. There was a statistically significant difference between the AUC values ( P= 0.023). The correlation between program performance and gold standard (correlation coefficient r (s)=0.525) was higher than that of observer performance and gold standard ( r (s)=0.457) and there was a statistically significant difference between the correlation coefficients ( P= 0.000). Conclusions: The program that automatically detects dental proximal caries lesions could improve the

  4. Mobile Phone Based Falling Detection Sensor and Computer-Aided Algorithm for Elderly People

    Directory of Open Access Journals (Sweden)

    Lee Jong-Ha

    2016-01-01

    Full Text Available Falls are dangerous for the elderly population; therefore many fall detection systems have been developed. However, previous methods are bulky for elderly people or only use a single sensor to isolate falls from daily living activities, which makes a fall difficult to distinguish. In this paper, we present a cost-effective and easy-to-use portable fall-detection sensor and algorithm. Specifically, to detect human falls, we used a three-axis accelerator and a three-axis gyroscope in a mobile phone. We used the Fourier descriptor-based frequency analysis method to classify both normal and falling status. From the experimental results, the proposed method detects falling status with 96.14% accuracy.

  5. DESIGN AND DEVELOP A COMPUTER AIDED DESIGN FOR AUTOMATIC EXUDATES DETECTION FOR DIABETIC RETINOPATHY SCREENING

    Directory of Open Access Journals (Sweden)

    C. A. SATHIYAMOORTHY

    2016-04-01

    Full Text Available Diabetic Retinopathy is a severe and widely spread eye disease which can lead to blindness. One of the main symptoms for vision loss is Exudates and it could be prevented by applying an early screening process. In the Existing systems, a Fuzzy C-Means Clustering technique is used for detecting the exudates for analyzation. The main objective of this paper is, to improve the efficiency of the Exudates detection in diabetic retinopathy images. To do this, a three Stage – [TS] approach is introduced for detecting and extracting the exudates automatically from the retinal images for screening the Diabetic retinopathy. TS functions on the image in three levels such as Pre-processing the image, enhancing the image and detecting the Exudates accurately. After successful detection, the detected exudates are classified using GLCM method for finding the accuracy. The TS approach is experimented using MATLAB software and the performance evaluation can be proved by comparing the results with the existing approach’s result and with the hand-drawn ground truths images from the expert ophthalmologist.

  6. Automatic bone detection and soft tissue aware ultrasound-CT registration for computer-aided orthopedic surgery.

    Science.gov (United States)

    Wein, Wolfgang; Karamalis, Athanasios; Baumgartner, Adrian; Navab, Nassir

    2015-06-01

    The transfer of preoperative CT data into the tracking system coordinates within an operating room is of high interest for computer-aided orthopedic surgery. In this work, we introduce a solution for intra-operative ultrasound-CT registration of bones. We have developed methods for fully automatic real-time bone detection in ultrasound images and global automatic registration to CT. The bone detection algorithm uses a novel bone-specific feature descriptor and was thoroughly evaluated on both in-vivo and ex-vivo data. A global optimization strategy aligns the bone surface, followed by a soft tissue aware intensity-based registration to provide higher local registration accuracy. We evaluated the system on femur, tibia and fibula anatomy in a cadaver study with human legs, where magnetically tracked bone markers were implanted to yield ground truth information. An overall median system error of 3.7 mm was achieved on 11 datasets. Global and fully automatic registration of bones aquired with ultrasound to CT is feasible, with bone detection and tracking operating in real time for immediate feedback to the surgeon.

  7. Quantitative computer-aided diagnostic algorithm for automated detection of peak lesion attenuation in differentiating clear cell from papillary and chromophobe renal cell carcinoma, oncocytoma, and fat-poor angiomyolipoma on multiphasic multidetector computed tomography.

    Science.gov (United States)

    Coy, Heidi; Young, Jonathan R; Douek, Michael L; Brown, Matthew S; Sayre, James; Raman, Steven S

    2017-07-01

    To evaluate the performance of a novel, quantitative computer-aided diagnostic (CAD) algorithm on four-phase multidetector computed tomography (MDCT) to detect peak lesion attenuation to enable differentiation of clear cell renal cell carcinoma (ccRCC) from chromophobe RCC (chRCC), papillary RCC (pRCC), oncocytoma, and fat-poor angiomyolipoma (fp-AML). We queried our clinical databases to obtain a cohort of histologically proven renal masses with preoperative MDCT with four phases [unenhanced (U), corticomedullary (CM), nephrographic (NP), and excretory (E)]. A whole lesion 3D contour was obtained in all four phases. The CAD algorithm determined a region of interest (ROI) of peak lesion attenuation within the 3D lesion contour. For comparison, a manual ROI was separately placed in the most enhancing portion of the lesion by visual inspection for a reference standard, and in uninvolved renal cortex. Relative lesion attenuation for both CAD and manual methods was obtained by normalizing the CAD peak lesion attenuation ROI (and the reference standard manually placed ROI) to uninvolved renal cortex with the formula [(peak lesion attenuation ROI - cortex ROI)/cortex ROI] × 100%. ROC analysis and area under the curve (AUC) were used to assess diagnostic performance. Bland-Altman analysis was used to compare peak ROI between CAD and manual method. The study cohort comprised 200 patients with 200 unique renal masses: 106 (53%) ccRCC, 32 (16%) oncocytomas, 18 (9%) chRCCs, 34 (17%) pRCCs, and 10 (5%) fp-AMLs. In the CM phase, CAD-derived ROI enabled characterization of ccRCC from chRCC, pRCC, oncocytoma, and fp-AML with AUCs of 0.850 (95% CI 0.732-0.968), 0.959 (95% CI 0.930-0.989), 0.792 (95% CI 0.716-0.869), and 0.825 (95% CI 0.703-0.948), respectively. On Bland-Altman analysis, there was excellent agreement of CAD and manual methods with mean differences between 14 and 26 HU in each phase. A novel, quantitative CAD algorithm enabled robust peak HU lesion detection

  8. Computer aided detection system for Osteoporosis using low dose thoracic 3D CT images

    Science.gov (United States)

    Tsuji, Daisuke; Matsuhiro, Mikio; Suzuki, Hidenobu; Kawata, Yoshiki; Niki, Noboru; Nakano, Yasutaka; Harada, Masafumi; Kusumoto, Masahiko; Tsuchida, Takaaki; Eguchi, Kenji; Kaneko, Masahiro

    2018-02-01

    The patient of osteoporosis is about 13 million people in Japan and it is one of healthy life problems in the aging society. It is necessary to do early stage detection and treatment in order to prevent the osteoporosis. Multi-slice CT technology has been improving the three dimensional (3D) image analysis with higher resolution and shorter scan time. The 3D image analysis of thoracic vertebra can be used for supporting to diagnosis of osteoporosis. This analysis can be used for lung cancer detection at the same time. We develop method of shape analysis and CT values of spongy bone for the detection osteoporosis. Osteoporosis and lung cancer screening show high extraction rate by the thoracic vertebral evaluation CT images. In addition, we created standard pattern of CT value per thoracic vertebra for male age group using 298 low dose data.

  9. EVALUATION OF A COMPUTER-AIDED SEMEN ANALYSIS SYSTEM WITH SPERM TAIL DETECTION

    NARCIS (Netherlands)

    WIJCHMAN, JG; DEWOLF, BTHM; JAGER, S

    The aim of this study was to evaluate the Stroemberg-Mika cell motion analyser (SM-CMA) which uses tail detection in order to discriminate between immotile spermatozoa and other particles. Analysis of the spermatozoa by the SM-CMA can easily be checked on a video monitor. The semen samples were from

  10. Computer aided detection of tumor and edema in brain FLAIR magnetic resonance image using ANN

    Science.gov (United States)

    Pradhan, Nandita; Sinha, A. K.

    2008-03-01

    This paper presents an efficient region based segmentation technique for detecting pathological tissues (Tumor & Edema) of brain using fluid attenuated inversion recovery (FLAIR) magnetic resonance (MR) images. This work segments FLAIR brain images for normal and pathological tissues based on statistical features and wavelet transform coefficients using k-means algorithm. The image is divided into small blocks of 4×4 pixels. The k-means algorithm is used to cluster the image based on the feature vectors of blocks forming different classes representing different regions in the whole image. With the knowledge of the feature vectors of different segmented regions, supervised technique is used to train Artificial Neural Network using fuzzy back propagation algorithm (FBPA). Segmentation for detecting healthy tissues and tumors has been reported by several researchers by using conventional MRI sequences like T1, T2 and PD weighted sequences. This work successfully presents segmentation of healthy and pathological tissues (both Tumors and Edema) using FLAIR images. At the end pseudo coloring of segmented and classified regions are done for better human visualization.

  11. Digital breast tomosynthesis: computer-aided detection of clustered microcalcifications on planar projection images

    International Nuclear Information System (INIS)

    Samala, Ravi K; Chan, Heang-Ping; Lu, Yao; Hadjiiski, Lubomir M; Wei, Jun; Helvie, Mark A

    2014-01-01

    This paper describes a new approach to detect microcalcification clusters (MCs) in digital breast tomosynthesis (DBT) via its planar projection (PPJ) image. With IRB approval, two-view (cranio-caudal and mediolateral oblique views) DBTs of human subject breasts were obtained with a GE GEN2 prototype DBT system that acquires 21 projection angles spanning 60° in 3° increments. A data set of 307 volumes (154 human subjects) was divided by case into independent training (127 with MCs) and test sets (104 with MCs and 76 free of MCs). A simultaneous algebraic reconstruction technique with multiscale bilateral filtering (MSBF) regularization was used to enhance microcalcifications and suppress noise. During the MSBF regularized reconstruction, the DBT volume was separated into high frequency (HF) and low frequency components representing microcalcifications and larger structures. At the final iteration, maximum intensity projection was applied to the regularized HF volume to generate a PPJ image that contained MCs with increased contrast-to-noise ratio (CNR) and reduced search space. High CNR objects in the PPJ image were extracted and labeled as microcalcification candidates. Convolution neural network trained to recognize the image pattern of microcalcifications was used to classify the candidates into true calcifications and tissue structures and artifacts. The remaining microcalcification candidates were grouped into MCs by dynamic conditional clustering based on adaptive CNR threshold and radial distance criteria. False positive (FP) clusters were further reduced using the number of candidates in a cluster, CNR and size of microcalcification candidates. At 85% sensitivity an FP rate of 0.71 and 0.54 was achieved for view- and case-based sensitivity, respectively, compared to 2.16 and 0.85 achieved in DBT. The improvement was significant (p-value = 0.003) by JAFROC analysis. (paper)

  12. Computer-Aided Manufacturing of 3D Workpieces

    OpenAIRE

    Cornelia Victoria Anghel Drugarin; Mihaela Dorica Stroia

    2017-01-01

    Computer-Aided Manufacturing (CAM) assumes to use dedicated software for controlling machine tools and similar devices in the process of workpieces manufacturing. CAM is, in fact, an application technology that uses computer software and machinery to simplify and automate manufacturing processes. CAM is the inheritor of computer-aided engineering (CAE) and is often used conjunctively with computer-aided design (CAD). Advanced CAM solutions are forthcoming and have a large ...

  13. Computer-aided diagnostic scheme for the detection of lung nodules on chest radiographs: Localized search method based on anatomical classification

    International Nuclear Information System (INIS)

    Shiraishi, Junji; Li Qiang; Suzuki, Kenji; Engelmann, Roger; Doi, Kunio

    2006-01-01

    We developed an advanced computer-aided diagnostic (CAD) scheme for the detection of various types of lung nodules on chest radiographs intended for implementation in clinical situations. We used 924 digitized chest images (992 noncalcified nodules) which had a 500x500 matrix size with a 1024 gray scale. The images were divided randomly into two sets which were used for training and testing of the computerized scheme. In this scheme, the lung field was first segmented by use of a ribcage detection technique, and then a large search area (448x448 matrix size) within the chest image was automatically determined by taking into account the locations of a midline and a top edge of the segmented ribcage. In order to detect lung nodule candidates based on a localized search method, we divided the entire search area into 7x7 regions of interest (ROIs: 64x64 matrix size). In the next step, each ROI was classified anatomically into apical, peripheral, hilar, and diaphragm/heart regions by use of its image features. Identification of lung nodule candidates and extraction of image features were applied for each localized region (128x128 matrix size), each having its central part (64x64 matrix size) located at a position corresponding to a ROI that was classified anatomically in the previous step. Initial candidates were identified by use of the nodule-enhanced image obtained with the average radial-gradient filtering technique, in which the filter size was varied adaptively depending on the location and the anatomical classification of the ROI. We extracted 57 image features from the original and nodule-enhanced images based on geometric, gray-level, background structure, and edge-gradient features. In addition, 14 image features were obtained from the corresponding locations in the contralateral subtraction image. A total of 71 image features were employed for three sequential artificial neural networks (ANNs) in order to reduce the number of false-positive candidates. All

  14. Computer Aided Design Tools for Extreme Environment Electronics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This project aims to provide Computer Aided Design (CAD) tools for radiation-tolerant, wide-temperature-range digital, analog, mixed-signal, and radio-frequency...

  15. [Clinical skills and outcomes of chair-side computer aided design and computer aided manufacture system].

    Science.gov (United States)

    Yu, Q

    2018-04-09

    Computer aided design and computer aided manufacture (CAD/CAM) technology is a kind of oral digital system which is applied to clinical diagnosis and treatment. It overturns the traditional pattern, and provides a solution to restore defect tooth quickly and efficiently. In this paper we mainly discuss the clinical skills of chair-side CAD/CAM system, including tooth preparation, digital impression, the three-dimensional design of prosthesis, numerical control machining, clinical bonding and so on, and review the outcomes of several common kinds of materials at the same time.

  16. The MAGIC-5 CAD for nodule detection in low dose and thin slice lung CTs

    International Nuclear Information System (INIS)

    Cerello, Piergiorgio

    2010-01-01

    Lung cancer is the leading cause of cancer-related mortality in developed countries. Only 10-15% of all men and women diagnosed with lung cancer live 5 years after the diagnosis. However, the 5-year survival rate for patients diagnosed in the early asymptomatic stage of the disease can reach 70%. Early-stage lung cancers can be diagnosed by detecting non-calcified small pulmonary nodules with computed tomography (CT). Computer-aided detection (CAD) could support radiologists in the analysis of the large amount of noisy images generated in screening programs, where low-dose and thin-slice settings are used. The MAGIC-5 project, funded by the Istituto Nazionale di Fisica Nucleare (INFN, Italy) and Ministero dell'Universita e della Ricerca (MUR, Italy), developed a multi-method approach based on three CAD algorithms to be used in parallel with a merging of their results: the Channeler Ant Model (CAM), based on Virtual Ant Colonies, the Dot-Enhancement/Pleura Surface Normals/VBNA (DE-PSN-VBNA), and the Region Growing Volume Plateau (RGVP). Preliminary results show quite good performances, to be improved with the refining of the single algorithm and the added value of the results merging.

  17. Fractography of clinically fractured, implant-supported dental computer-aided design and computer-aided manufacturing crowns

    NARCIS (Netherlands)

    Lohbauer, Ulrich; Belli, Renan; Cune, Marco S; Schepke, Ulf

    2017-01-01

    Today, a substantial part of the dental crown production uses computer-aided design and computer-aided manufacturing (CAD/CAM) technology. A recent step in restorative dentistry is the replacement of natural tooth structure with pre-polymerized and machined resin-based methacrylic polymers.

  18. Computer-aided diagnosis in routine mammography

    International Nuclear Information System (INIS)

    Sittek, H.; Perlet, C.; Helmberger, R.; Linsmeier, E.; Kessler, M.; Reiser, M.

    1998-01-01

    Purpose: Computer-aided diagnosis in mammography is a topic many study groups have been concerned with since the first presentation of a system for computer-aided interpretation in 1967. Currently, there is only one system avilable for clinical use in mammography, the CAD-System Image Checker (R2 Technology). The purpose of our prospective study was to evaluate whether the integration of the CAD-system into the routine of a radiological breast diagnosis unit is feasible. Results: After the installation of the CAD-system, 300 patients with 1110 mammograms were included for evaluation in the present study. In 54 of these cases histological examination was indicated due to suspect criteria on conventional mammography. In 39 of 54 cases (72,2%) malignancy could be proven histologically. The CAD-system marked 82,1% of the histologically verified carcinomas correctly 94,3% of all 1797 marks made by the CAD-system indicated normal or benign structures. Routinely performed CAD analysis prolonged patients waiting time by about 15 min because the marks of the CAD system had to be interpreted in addition to the routine diagnostic investigations. Conclusion: Our experience with the use of the CAD-system in daily routine showed that CAD analysis can easily be integrated into a preexisting mammography unit. However, the diagnostic benefit is not yet clearly established. Since the rate of false negative marks by the CAD-system Image Checker is still high, the results of CAD analysis must be checked and corrected by an observer well experienced in mammography reading. (orig.) [de

  19. Computer aided diagnosis of diabetic peripheral neuropathy

    Science.gov (United States)

    Chekh, Viktor; Soliz, Peter; McGrew, Elizabeth; Barriga, Simon; Burge, Mark; Luan, Shuang

    2014-03-01

    Diabetic peripheral neuropathy (DPN) refers to the nerve damage that can occur in diabetes patients. It most often affects the extremities, such as the feet, and can lead to peripheral vascular disease, deformity, infection, ulceration, and even amputation. The key to managing diabetic foot is prevention and early detection. Unfortunately, current existing diagnostic techniques are mostly based on patient sensations and exhibit significant inter- and intra-observer differences. We have developed a computer aided diagnostic (CAD) system for diabetic peripheral neuropathy. The thermal response of the feet of diabetic patients following cold stimulus is captured using an infrared camera. The plantar foot in the images from a thermal video are segmented and registered for tracking points or specific regions. The temperature recovery of each point on the plantar foot is extracted using our bio-thermal model and analyzed. The regions that exhibit abnormal ability to recover are automatically identified to aid the physicians to recognize problematic areas. The key to our CAD system is the segmentation of infrared video. The main challenges for segmenting infrared video compared to normal digital video are (1) as the foot warms up, it also warms up the surrounding, creating an ever changing contrast; and (2) there may be significant motion during imaging. To overcome this, a hybrid segmentation algorithm was developed based on a number of techniques such as continuous max-flow, model based segmentation, shape preservation, convex hull, and temperature normalization. Verifications of the automatic segmentation and registration using manual segmentation and markers show good agreement.

  20. An esthetics rehabilitation with computer-aided design/ computer-aided manufacturing technology.

    Science.gov (United States)

    Mazaro, Josá Vitor Quinelli; de Mello, Caroline Cantieri; Zavanelli, Adriana Cristina; Santiago, Joel Ferreira; Amoroso, Andressa Paschoal; Pellizzer, Eduardo Piza

    2014-07-01

    This paper describes a case of a rehabilitation involving Computer Aided Design/Computer Aided Manufacturing (CAD-CAM) system in implant supported and dental supported prostheses using zirconia as framework. The CAD-CAM technology has developed considerably over last few years, becoming a reality in dental practice. Among the widely used systems are the systems based on zirconia which demonstrate important physical and mechanical properties of high strength, adequate fracture toughness, biocompatibility and esthetics, and are indicated for unitary prosthetic restorations and posterior and anterior framework. All the modeling was performed by using CAD-CAM system and prostheses were cemented using resin cement best suited for each situation. The rehabilitation of the maxillary arch using zirconia framework demonstrated satisfactory esthetic and functional results after a 12-month control and revealed no biological and technical complications. This article shows the important of use technology CAD/CAM in the manufacture of dental prosthesis and implant-supported.

  1. Detection of a possible epilepsy focus in a preoperated patient by perfusion SPECT and computer-aided subtraction analysis

    International Nuclear Information System (INIS)

    Apostolova, I.; Wilke, F.; Clausen, M.; Buchert, R.; Lindenau, M.; Stodieck, S.; Fiehler, J.; Heese, O.

    2008-01-01

    Ictal perfusion SPECT with either 9 9mTc-hexamethylpropylene amine oxime (HMPAO) or 9 9mTc-ethylcysteinate dimer (ECD) has been reported to provide very good sensitivity for the determination of the SOA in fTLE. Sensitivity of interictal perfusion SPECT is much lower. However, interictal perfusion SPECT might enhance the specificity of ictal SPECT findings by improving the discrimination between seizure related local hyperperfusion and intersubject variability of perfusion (physiologic hyperperfusion). In addition, the combination of interictal and ictal perfusion SPECT might provide improved sensitivity compared to ictal SPECT alone, particularly when computer-aided subtraction of ictal and interictal SPECT is used instead of traditional side-by-side visual comparison. The combination of ictal and interictal perfusion SPECT eliminates not only physiological inter-subject variance, but it can also eliminate severe partial volume effects. Computer-aided subtraction analysis appears particularly useful in this case

  2. Detection of a possible epilepsy focus in a preoperated patient by perfusion SPECT and computer-aided subtraction analysis

    Energy Technology Data Exchange (ETDEWEB)

    Apostolova, I.; Wilke, F.; Clausen, M.; Buchert, R. [Univ. Medical Center Hamburg-Eppendorf (Germany). Dept. of Nuclear Medicine; Lindenau, M.; Stodieck, S. [Protestant Hospital Alsterdorf, Hamburg (Germany). Dept. of Neurology and Epileptology; Fiehler, J. [Univ. Medical Center Hamburg-Eppendorf (Germany). Dept. of Neuroradiology; Heese, O. [Univ. Medical Center Hamburg-Eppendorf (Germany). Neurological Surgery

    2008-07-01

    Ictal perfusion SPECT with either {sup 9}9mTc-hexamethylpropylene amine oxime (HMPAO) or {sup 9}9mTc-ethylcysteinate dimer (ECD) has been reported to provide very good sensitivity for the determination of the SOA in fTLE. Sensitivity of interictal perfusion SPECT is much lower. However, interictal perfusion SPECT might enhance the specificity of ictal SPECT findings by improving the discrimination between seizure related local hyperperfusion and intersubject variability of perfusion (physiologic hyperperfusion). In addition, the combination of interictal and ictal perfusion SPECT might provide improved sensitivity compared to ictal SPECT alone, particularly when computer-aided subtraction of ictal and interictal SPECT is used instead of traditional side-by-side visual comparison. The combination of ictal and interictal perfusion SPECT eliminates not only physiological inter-subject variance, but it can also eliminate severe partial volume effects. Computer-aided subtraction analysis appears particularly useful in this case.

  3. Computer-aided diagnosis for screening of breast cancer on mammograms. Current status and future potential

    International Nuclear Information System (INIS)

    Doi, Kunio

    2007-01-01

    Described are the history, current status and future potential of computer-aided diagnosis (CAD) with particular emphasis on screening mammography for breast cancer. The systematic basic and clinical studies on CAD started around 20 years before and the significance of CAD has been well recognized to be evident because of human errors occurring in the visual check by doctors of so numerous screening images. Improvement of diagnostic accuracy by CAD has been demonstrated by statistical analysis of ROC (receiver operating characteristic) curves. In mammography, reviewed is detection of the early stage breast cancer like microcalcifications by computer alone, by CAD plus one or more doctors' reading, and by practical clinical CAD diagnosis. For differential diagnosis for malignancy, microcalcifications and masses are given their characteristic image properties and the results are that the Az-value (area under ROC curve) is higher in CAD than in doctor's (0.80 vs 0.61) in the former and, doctor's (0.93) is improved by CAD to 0.96 in the latter masses. In this diagnosis, similar images in the digital database are useful and the database can learn by repeated input of individual data by neural network. Detection of the lesion and especially, its differential diagnosis will be more important in parallel to database development and CAD will be also useful for doctor' carrier as an educational mean. (R.T.)

  4. [Development of a Computer-aided Diagnosis System to Distinguish between Benign and Malignant Mammary Tumors in Dynamic Magnetic Resonance Images: Automatic Detection of the Position with the Strongest Washout Effect in the Tumor].

    Science.gov (United States)

    Miyazaki, Yoshiaki; Tabata, Nobuyuki; Taroura, Tomomi; Shinozaki, Kenji; Kubo, Yuichiro; Tokunaga, Eriko; Taguchi, Kenichi

    We propose a computer-aided diagnostic (CAD) system that uses time-intensity curves to distinguish between benign and malignant mammary tumors. Many malignant tumors show a washout pattern in time-intensity curves. Therefore, we designed a program that automatically detects the position with the strongest washout effect using the technique, such as the subtraction technique, which extracts only the washout area in the tumor, and by scanning data in 2×2 pixel region of interest (ROI). Operation of this independently developed program was verified using a phantom system that simulated tumors. In three cases of malignant tumors, the washout pattern detection rate in images with manually set ROI was ≤6%, whereas the detection rate with our novel method was 100%. In one case of a benign tumor, when the same method was used, we checked that there was no washout effect and detected the persistent pattern. Thus, the distinction between benign and malignant tumors using our method was completely consistent with the pathological diagnoses made. Our novel method is therefore effective for differentiating between benign and malignant mammary tumors in dynamic magnetic resonance images.

  5. Integrated computer-aided design using minicomputers

    Science.gov (United States)

    Storaasli, O. O.

    1980-01-01

    Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), a highly interactive software, has been implemented on minicomputers at the NASA Langley Research Center. CAD/CAM software integrates many formerly fragmented programs and procedures into one cohesive system; it also includes finite element modeling and analysis, and has been interfaced via a computer network to a relational data base management system and offline plotting devices on mainframe computers. The CAD/CAM software system requires interactive graphics terminals operating at a minimum of 4800 bits/sec transfer rate to a computer. The system is portable and introduces 'interactive graphics', which permits the creation and modification of models interactively. The CAD/CAM system has already produced designs for a large area space platform, a national transonic facility fan blade, and a laminar flow control wind tunnel model. Besides the design/drafting element analysis capability, CAD/CAM provides options to produce an automatic program tooling code to drive a numerically controlled (N/C) machine. Reductions in time for design, engineering, drawing, finite element modeling, and N/C machining will benefit productivity through reduced costs, fewer errors, and a wider range of configuration.

  6. Evaluation of a computer-aided detection algorithm for timely diagnosis of small acute intracranial hemorrhage on computed tomography in a critical care environment

    Science.gov (United States)

    Lee, Joon K.; Chan, Tao; Liu, Brent J.; Huang, H. K.

    2009-02-01

    Detection of acute intracranial hemorrhage (AIH) is a primary task in the interpretation of computed tomography (CT) brain scans of patients suffering from acute neurological disturbances or after head trauma. Interpretation can be difficult especially when the lesion is inconspicuous or the reader is inexperienced. We have previously developed a computeraided detection (CAD) algorithm to detect small AIH. One hundred and thirty five small AIH CT studies from the Los Angeles County (LAC) + USC Hospital were identified and matched by age and sex with one hundred and thirty five normal studies. These cases were then processed using our AIH CAD system to evaluate the efficacy and constraints of the algorithm.

  7. Computer-Aided Detection with a Portable Electrocardiographic Recorder and Acceleration Sensors for Monitoring Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Ji-Won Baek

    2014-03-01

    Full Text Available Obstructive sleep apnea syndrome is a sleep-related breathing disorder that is caused by obstruction of the upper airway. This condition may be related with many clinical sequelae such as cardiovascular disease, high blood pressure, stroke, diabetes, and clinical depression. To diagnosis obstructive sleep apnea, in-laboratory full polysomnography is considered as a standard test to determine the severity of respiratory disturbance. However, polysomnography is expensive and complicated to perform. In this research, we explore a computer-aided diagnosis system with portable ECG equipment and tri-accelerometer (x, y, and z-axes that can automatically analyze biosignals and test for OSA. Traditional approaches to sleep apnea data analysis have been criticized; however, there are not enough suggestions to resolve the existing problems. As an effort to resolve this issue, we developed an approach to record ECG signals and abdominal movements induced by breathing by affixing ECG-enabled electrodes onto a triaxial accelerometer. With the two signals simultaneously measured, the apnea data obtained would be more accurate, relative to cases where a single signal is measured. This would be helpful in diagnosing OSA. Moreover, a useful feature point can be extracted from the two signals after applying a signal processing algorithm, and the extracted feature point can be applied in designing a computer-aided diagnosis algorithm using a machine learning technique.

  8. [Key points for esthetic rehabilitation of anterior teeth using chair-side computer aided design and computer aided manufacture technique].

    Science.gov (United States)

    Yang, J; Feng, H L

    2018-04-09

    With the rapid development of the chair-side computer aided design and computer aided manufacture (CAD/CAM) technology, its accuracy and operability of have been greatly improved in recent years. Chair-side CAD/CAM system may produce all kinds of indirect restorations, and has the advantages of rapid, accurate and stable production. It has become the future development direction of Stomatology. This paper describes the clinical application of the chair-side CAD/CAM technology for anterior aesthetic restorations from the aspects of shade and shape.

  9. Machine Learning in Ultrasound Computer-Aided Diagnostic Systems: A Survey.

    Science.gov (United States)

    Huang, Qinghua; Zhang, Fan; Li, Xuelong

    2018-01-01

    The ultrasound imaging is one of the most common schemes to detect diseases in the clinical practice. There are many advantages of ultrasound imaging such as safety, convenience, and low cost. However, reading ultrasound imaging is not easy. To support the diagnosis of clinicians and reduce the load of doctors, many ultrasound computer-aided diagnosis (CAD) systems are proposed. In recent years, the success of deep learning in the image classification and segmentation led to more and more scholars realizing the potential of performance improvement brought by utilizing the deep learning in the ultrasound CAD system. This paper summarized the research which focuses on the ultrasound CAD system utilizing machine learning technology in recent years. This study divided the ultrasound CAD system into two categories. One is the traditional ultrasound CAD system which employed the manmade feature and the other is the deep learning ultrasound CAD system. The major feature and the classifier employed by the traditional ultrasound CAD system are introduced. As for the deep learning ultrasound CAD, newest applications are summarized. This paper will be useful for researchers who focus on the ultrasound CAD system.

  10. Machine Learning in Ultrasound Computer-Aided Diagnostic Systems: A Survey

    Directory of Open Access Journals (Sweden)

    Qinghua Huang

    2018-01-01

    Full Text Available The ultrasound imaging is one of the most common schemes to detect diseases in the clinical practice. There are many advantages of ultrasound imaging such as safety, convenience, and low cost. However, reading ultrasound imaging is not easy. To support the diagnosis of clinicians and reduce the load of doctors, many ultrasound computer-aided diagnosis (CAD systems are proposed. In recent years, the success of deep learning in the image classification and segmentation led to more and more scholars realizing the potential of performance improvement brought by utilizing the deep learning in the ultrasound CAD system. This paper summarized the research which focuses on the ultrasound CAD system utilizing machine learning technology in recent years. This study divided the ultrasound CAD system into two categories. One is the traditional ultrasound CAD system which employed the manmade feature and the other is the deep learning ultrasound CAD system. The major feature and the classifier employed by the traditional ultrasound CAD system are introduced. As for the deep learning ultrasound CAD, newest applications are summarized. This paper will be useful for researchers who focus on the ultrasound CAD system.

  11. Computer aided safety analysis

    International Nuclear Information System (INIS)

    1988-05-01

    The document reproduces 20 selected papers from the 38 papers presented at the Technical Committee/Workshop on Computer Aided Safety Analysis organized by the IAEA in co-operation with the Institute of Atomic Energy in Otwock-Swierk, Poland on 25-29 May 1987. A separate abstract was prepared for each of these 20 technical papers. Refs, figs and tabs

  12. Teaching Computer-Aided Design of Fluid Flow and Heat Transfer Engineering Equipment.

    Science.gov (United States)

    Gosman, A. D.; And Others

    1979-01-01

    Describes a teaching program for fluid mechanics and heat transfer which contains both computer aided learning (CAL) and computer aided design (CAD) components and argues that the understanding of the physical and numerical modeling taught in the CAL course is essential to the proper implementation of CAD. (Author/CMV)

  13. 64006 CAD i Byggesektoren. Grundkursus

    DEFF Research Database (Denmark)

    Borchersen, Egil

    1998-01-01

    Overview on Computer Aided Design in Civil Engineering and introduction to AutoCAD version 13, layers, colours, blocks, attributes.......Overview on Computer Aided Design in Civil Engineering and introduction to AutoCAD version 13, layers, colours, blocks, attributes....

  14. Computer aided product design

    DEFF Research Database (Denmark)

    Constantinou, Leonidas; Bagherpour, Khosrow; Gani, Rafiqul

    1996-01-01

    A general methodology for Computer Aided Product Design (CAPD) with specified property constraints which is capable of solving a large range of problems is presented. The methodology employs the group contribution approach, generates acyclic, cyclic and aromatic compounds of various degrees......-liquid equilibria (LLE), solid-liquid equilibria (SLE) and gas solubility. Finally, a computer program based on the extended methodology has been developed and the results from five case studies highlighting various features of the methodology are presented....

  15. Adhesive Bonding to Computer-aided Design/ Computer-aided Manufacturing Esthetic Dental Materials: An Overview.

    Science.gov (United States)

    Awad, Mohamed Moustafa; Alqahtani, H; Al-Mudahi, A; Murayshed, M S; Alrahlah, A; Bhandi, Shilpa H

    2017-07-01

    To review the adhesive bonding to different computer-aided design/computer-aided manufacturing (CAD/CAM) esthetic restorative materials. The use of CAD/CAM esthetic restorative materials has gained popularity in recent years. Several CAD/ CAM esthetic restorative materials are commercially available. Adhesive bonding is a major determinant of success of CAD/ CAM restorations. Review result: An account of the currently available bonding strategies are discussed with their rationale in various CAD/ CAM materials. Different surface treatment methods as well as adhesion promoters can be used to achieve reliable bonding of CAD/CAM restorative materials. Selection of bonding strategy to such material is determined based on its composition. Further evidence is required to evaluate the effect of new surface treatment methods, such as nonthermal atmospheric plasma and self-etching ceramic primer on bonding to different dental ceramics. An understanding of the currently available bonding strategies to CA/CAM materials can help the clinician to select the most indicated system for each category of materials.

  16. Computer-aided engineering in High Energy Physics

    International Nuclear Information System (INIS)

    Bachy, G.; Hauviller, C.; Messerli, R.; Mottier, M.

    1988-01-01

    Computing, standard tool for a long time in the High Energy Physics community, is being slowly introduced at CERN in the mechanical engineering field. The first major application was structural analysis followed by Computer-Aided Design (CAD). Development work is now progressing towards Computer-Aided Engineering around a powerful data base. This paper gives examples of the power of this approach applied to engineering for accelerators and detectors

  17. A Computer-Aided Diagnosis for Evaluating Lung Nodules on Chest CT: the Current Status and Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Jin Mo [Seoul National University Medical Research Center, Seoul (Korea, Republic of)

    2011-04-15

    As the detection and characterization of lung nodules are of paramount importance in thoracic radiology, various tools for making a computer-aided diagnosis (CAD) have been developed to improve the diagnostic performance of radiologists in clinical practice. Numerous studies over the years have shown that the CAD system can effectively help readers identify more nodules. Moreover, nodule malignancy and the response of malignant lung tumors to treatment can also be assessed using nodule volumetry. CAD also has the potential to objectively analyze the morphology of nodules and enhance the work flow during the assessment of follow-up studies. Therefore, understanding the current status and limitations of CAD for evaluating lung nodules is essential to effectively apply CAD in clinical practice

  18. Computer-aided diagnosis and artificial intelligence in clinical imaging.

    Science.gov (United States)

    Shiraishi, Junji; Li, Qiang; Appelbaum, Daniel; Doi, Kunio

    2011-11-01

    Computer-aided diagnosis (CAD) is rapidly entering the radiology mainstream. It has already become a part of the routine clinical work for the detection of breast cancer with mammograms. The computer output is used as a "second opinion" in assisting radiologists' image interpretations. The computer algorithm generally consists of several steps that may include image processing, image feature analysis, and data classification via the use of tools such as artificial neural networks (ANN). In this article, we will explore these and other current processes that have come to be referred to as "artificial intelligence." One element of CAD, temporal subtraction, has been applied for enhancing interval changes and for suppressing unchanged structures (eg, normal structures) between 2 successive radiologic images. To reduce misregistration artifacts on the temporal subtraction images, a nonlinear image warping technique for matching the previous image to the current one has been developed. Development of the temporal subtraction method originated with chest radiographs, with the method subsequently being applied to chest computed tomography (CT) and nuclear medicine bone scans. The usefulness of the temporal subtraction method for bone scans was demonstrated by an observer study in which reading times and diagnostic accuracy improved significantly. An additional prospective clinical study verified that the temporal subtraction image could be used as a "second opinion" by radiologists with negligible detrimental effects. ANN was first used in 1990 for computerized differential diagnosis of interstitial lung diseases in CAD. Since then, ANN has been widely used in CAD schemes for the detection and diagnosis of various diseases in different imaging modalities, including the differential diagnosis of lung nodules and interstitial lung diseases in chest radiography, CT, and position emission tomography/CT. It is likely that CAD will be integrated into picture archiving and

  19. Contralateral lesions detected by preoperative MRI in patients with recently diagnosed breast cancer: Application of MR CAD in differentiation of benign and malignant lesions

    International Nuclear Information System (INIS)

    Cho, Nariya; Kim, Sun Mi; Park, Jeong Seon; Jang, Mijung; Kim, Soo-Yeon; Chang, Jung Min; Moon, Woo Kyung

    2012-01-01

    Objectives: To retrospectively investigate the added value of kinetic features measured by computer-aided diagnosis (CAD) for differentiating benign and malignant contralateral breast lesions detected by preoperative MRI in breast cancer patients. Methods: This study was approved by our institutional review board, and the requirement for informed consent was waived. Fifty-two breast MR images and their CAD kinetic features were obtained for 52 consecutive breast cancer patients with contralateral breast lesions detected by preoperative MRI and confirmed by excision (23 cancers and 29 benign lesions). Three experienced radiologists independently reviewed the MR images without CAD information and assessed probabilities of malignancy. Four weeks later, these probabilities were reanalyzed using stored CAD data. Diagnostic performances and detection rates of delayed washout components were compared between interpretations without and with CAD for each reader. Results: Use of MR CAD increased detection of washout component by 2.4- to 3.7-fold than visual assessment for enhancing contralateral lesions, which increased sensitivity (91% vs. 87% in reader 1; 96% vs. 74% in reader 2; 91% vs. 70% in reader 3) and decreased specificity, but statistical significance was only found for decreased specificity in one reader (52% vs. 28%, P = 0.039), and overall performance (areas under ROC curves 0.672 vs. 0.616 in reader 1; 0.624 vs. 0.603 in reader 2; 0.706 vs. 0.590 in reader 3) remained unimproved. Conclusion: Addition of MR CAD increased sensitivity and decreased specificity than radiologist's assessment alone for differentiating benign and malignant contralateral lesions in breast cancer patients and overall performance remained unimproved.

  20. [Development of computer aided forming techniques in manufacturing scaffolds for bone tissue engineering].

    Science.gov (United States)

    Wei, Xuelei; Dong, Fuhui

    2011-12-01

    To review recent advance in the research and application of computer aided forming techniques for constructing bone tissue engineering scaffolds. The literature concerning computer aided forming techniques for constructing bone tissue engineering scaffolds in recent years was reviewed extensively and summarized. Several studies over last decade have focused on computer aided forming techniques for bone scaffold construction using various scaffold materials, which is based on computer aided design (CAD) and bone scaffold rapid prototyping (RP). CAD include medical CAD, STL, and reverse design. Reverse design can fully simulate normal bone tissue and could be very useful for the CAD. RP techniques include fused deposition modeling, three dimensional printing, selected laser sintering, three dimensional bioplotting, and low-temperature deposition manufacturing. These techniques provide a new way to construct bone tissue engineering scaffolds with complex internal structures. With rapid development of molding and forming techniques, computer aided forming techniques are expected to provide ideal bone tissue engineering scaffolds.

  1. Computer aided drug design

    Science.gov (United States)

    Jain, A.

    2017-08-01

    Computer based method can help in discovery of leads and can potentially eliminate chemical synthesis and screening of many irrelevant compounds, and in this way, it save time as well as cost. Molecular modeling systems are powerful tools for building, visualizing, analyzing and storing models of complex molecular structure that can help to interpretate structure activity relationship. The use of various techniques of molecular mechanics and dynamics and software in Computer aided drug design along with statistics analysis is powerful tool for the medicinal chemistry to synthesis therapeutic and effective drugs with minimum side effect.

  2. Improved mammographic interpretation of masses using computer-aided diagnosis

    International Nuclear Information System (INIS)

    Leichter, I.; Fields, S.; Novak, B.; Nirel, R.; Bamberger, P.; Lederman, R.; Buchbinder, S.

    2000-01-01

    The aim of this study was to evaluate the effectiveness of computerized image enhancement, to investigate criteria for discriminating benign from malignant mammographic findings by computer-aided diagnosis (CAD), and to test the role of quantitative analysis in improving the accuracy of interpretation of mass lesions. Forty sequential mammographically detected mass lesions referred for biopsy were digitized at high resolution for computerized evaluation. A prototype CAD system which included image enhancement algorithms was used for a better visualization of the lesions. Quantitative features which characterize the spiculation were automatically extracted by the CAD system for a user-defined region of interest (ROI). Reference ranges for malignant and benign cases were acquired from data generated by 214 known retrospective cases. The extracted parameters together with the reference ranges were presented to the radiologist for the analysis of 40 prospective cases. A pattern recognition scheme based on discriminant analysis was trained on the 214 retrospective cases, and applied to the prospective cases. Accuracy of interpretation with and without the CAD system, as well as the performance of the pattern recognition scheme, were analyzed using receiver operating characteristics (ROC) curves. A significant difference (p z ) increased significantly (p z for the results of the pattern recognition scheme was higher (0.95). The results indicate that there is an improved accuracy of diagnosis with the use of the mammographic CAD system above that of the unassisted radiologist. Our findings suggest that objective quantitative features extracted from digitized mammographic findings may help in differentiating between benign and malignant masses, and can assist the radiologist in the interpretation of mass lesions. (orig.)

  3. Computer-aided diagnosis in medical imaging: historical review, current status and future potential.

    Science.gov (United States)

    Doi, Kunio

    2007-01-01

    Computer-aided diagnosis (CAD) has become one of the major research subjects in medical imaging and diagnostic radiology. In this article, the motivation and philosophy for early development of CAD schemes are presented together with the current status and future potential of CAD in a PACS environment. With CAD, radiologists use the computer output as a "second opinion" and make the final decisions. CAD is a concept established by taking into account equally the roles of physicians and computers, whereas automated computer diagnosis is a concept based on computer algorithms only. With CAD, the performance by computers does not have to be comparable to or better than that by physicians, but needs to be complementary to that by physicians. In fact, a large number of CAD systems have been employed for assisting physicians in the early detection of breast cancers on mammograms. A CAD scheme that makes use of lateral chest images has the potential to improve the overall performance in the detection of lung nodules when combined with another CAD scheme for PA chest images. Because vertebral fractures can be detected reliably by computer on lateral chest radiographs, radiologists' accuracy in the detection of vertebral fractures would be improved by the use of CAD, and thus early diagnosis of osteoporosis would become possible. In MRA, a CAD system has been developed for assisting radiologists in the detection of intracranial aneurysms. On successive bone scan images, a CAD scheme for detection of interval changes has been developed by use of temporal subtraction images. In the future, many CAD schemes could be assembled as packages and implemented as a part of PACS. For example, the package for chest CAD may include the computerized detection of lung nodules, interstitial opacities, cardiomegaly, vertebral fractures, and interval changes in chest radiographs as well as the computerized classification of benign and malignant nodules and the differential diagnosis of

  4. Improved mammographic interpretation of masses using computer-aided diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Leichter, I. [Dept. of Electro-Optics, Jerusalem College of Technology (Israel); Fields, S.; Novak, B. [Dept. of Radiology, Hadassah University Hospital, Mt. Scopus Jerusalem (Israel); Nirel, R. [Dept. of Statistics, Hebrew University of Jerusalem, Mt. Scopus, Jerusalem (Israel); Bamberger, P. [Dept. of Electronics, Jerusalem College of Technology, Jerusalem (Israel); Lederman, R. [Department of Radiology, Hadassah University Hospital, Ein Kerem, Jerusalem (Israel); Buchbinder, S. [Department of Radiology, Montefiore Medical Center, University Hospital for the Albert Einstein College of Medicine, Bronx, New York (United States)

    2000-02-01

    The aim of this study was to evaluate the effectiveness of computerized image enhancement, to investigate criteria for discriminating benign from malignant mammographic findings by computer-aided diagnosis (CAD), and to test the role of quantitative analysis in improving the accuracy of interpretation of mass lesions. Forty sequential mammographically detected mass lesions referred for biopsy were digitized at high resolution for computerized evaluation. A prototype CAD system which included image enhancement algorithms was used for a better visualization of the lesions. Quantitative features which characterize the spiculation were automatically extracted by the CAD system for a user-defined region of interest (ROI). Reference ranges for malignant and benign cases were acquired from data generated by 214 known retrospective cases. The extracted parameters together with the reference ranges were presented to the radiologist for the analysis of 40 prospective cases. A pattern recognition scheme based on discriminant analysis was trained on the 214 retrospective cases, and applied to the prospective cases. Accuracy of interpretation with and without the CAD system, as well as the performance of the pattern recognition scheme, were analyzed using receiver operating characteristics (ROC) curves. A significant difference (p < 0.005) was found between features extracted by the CAD system for benign and malignant cases. Specificity of the CAD-assisted diagnosis improved significantly (p < 0.02) from 14 % for the conventional assessment to 50 %, and the positive predictive value increased from 0.47 to 0.62 (p < 0.04). The area under the ROC curve (A{sub z}) increased significantly (p < 0.001) from 0.66 for the conventional assessment to 0.81 for the CAD-assisted analysis. The A{sub z} for the results of the pattern recognition scheme was higher (0.95). The results indicate that there is an improved accuracy of diagnosis with the use of the mammographic CAD system above that

  5. Computer aided control engineering

    DEFF Research Database (Denmark)

    Szymkat, Maciej; Ravn, Ole

    1997-01-01

    Current developments in the field of Computer Aided Control Engineering (CACE) have a visible impact on the design methodologies and the structure of the software tools supporting them. Today control engineers has at their disposal libraries, packages or programming environments that may...... in CACE enhancing efficient flow of information between the tools supporting the following phases of the design process. In principle, this flow has to be two-way, and more or less automated, in order to enable the engineer to observe the propagation of the particular design decisions taken at various...... levels.The major conclusions of the paper are related with identifying the factors affecting the software tool integration in a way needed to facilitate design "inter-phase" communication. These are: standard application interfaces, dynamic data exchange mechanisms, code generation techniques and general...

  6. CAD-guidelines

    International Nuclear Information System (INIS)

    Schlechtendahl, E.G.; Lang-Lendorff, G.

    1982-10-01

    The CAD-guidelines (CAD = Computer Aided Design) contain rules for programming, structuring and documentation of programs. The standard deals with the structure of CAD-programs, their components, the programming-methods, the language etc. It describes what documents and references are necessary for a CAD-program. In order to gain a broad application of CAD criteria like portability and completeness of the documentation for an effective maintenance are as important as a transparent way of producing CAD-software. (orig.) [de

  7. Bomb CAD

    International Nuclear Information System (INIS)

    Massa, R.J.; Howard, J.W.

    1989-01-01

    This paper describes BombCAD a computer-aided analysis technique for assessing the damage to diverse structures which results from specific high explosive detonations within or near the structure. BombCAD analyzes the vulnerability of specific facilities to bomb attach, and evaluates siting, screening and hardening/softening aspects of comprehensive bomb defense programs. The paper describes BombCAD's architectural models of specific structures, computations of blastwave effects and the paradigms which relate blast wave effects to both structural damage and human injury. The use of BombCAD in bomb attack vulnerability assessment, facility design, bomb threat response planning and post-incident analyses is described and field examples are presented

  8. Modeling electric fields in two dimensions using computer aided design

    International Nuclear Information System (INIS)

    Gilmore, D.W.; Giovanetti, D.

    1992-01-01

    The authors describe a method for analyzing static electric fields in two dimensions using AutoCAD. The algorithm is coded in LISP and is modeled after Coloumb's Law. The software platform allows for facile graphical manipulations of field renderings and supports a wide range of hardcopy-output and data-storage formats. More generally, this application is representative of the ability to analyze data that is the solution to known mathematical functions with computer aided design (CAD)

  9. Computer aided photographic engineering

    Science.gov (United States)

    Hixson, Jeffrey A.; Rieckhoff, Tom

    1988-01-01

    High speed photography is an excellent source of engineering data but only provides a two-dimensional representation of a three-dimensional event. Multiple cameras can be used to provide data for the third dimension but camera locations are not always available. A solution to this problem is to overlay three-dimensional CAD/CAM models of the hardware being tested onto a film or photographic image, allowing the engineer to measure surface distances, relative motions between components, and surface variations.

  10. CAD: Designs on Business.

    Science.gov (United States)

    Milburn, Ken

    1988-01-01

    Provides a general review of the field of Computer-Aided Design Software including specific reviews of "Autosketch,""Generic CADD,""Drafix 1 Plus,""FastCAD," and "Autocad Release 9." Brief articles include "Blueprint for Generation,""CAD for Every Department,""Ideas…

  11. Potential clinical impact of advanced imaging and computer-aided diagnosis in chest radiology: importance of radiologist's role and successful observer study.

    Science.gov (United States)

    Li, Feng

    2015-07-01

    This review paper is based on our research experience in the past 30 years. The importance of radiologists' role is discussed in the development or evaluation of new medical images and of computer-aided detection (CAD) schemes in chest radiology. The four main topics include (1) introducing what diseases can be included in a research database for different imaging techniques or CAD systems and what imaging database can be built by radiologists, (2) understanding how radiologists' subjective judgment can be combined with technical objective features to improve CAD performance, (3) sharing our experience in the design of successful observer performance studies, and (4) finally, discussing whether the new images and CAD systems can improve radiologists' diagnostic ability in chest radiology. In conclusion, advanced imaging techniques and detection/classification of CAD systems have a potential clinical impact on improvement of radiologists' diagnostic ability, for both the detection and the differential diagnosis of various lung diseases, in chest radiology.

  12. Computer-aided assessment of diagnostic images for epidemiological research

    Directory of Open Access Journals (Sweden)

    Gange Stephen J

    2009-11-01

    Full Text Available Abstract Background Diagnostic images are often assessed for clinical outcomes using subjective methods, which are limited by the skill of the reviewer. Computer-aided diagnosis (CAD algorithms that assist reviewers in their decisions concerning outcomes have been developed to increase sensitivity and specificity in the clinical setting. However, these systems have not been well utilized in research settings to improve the measurement of clinical endpoints. Reductions in bias through their use could have important implications for etiologic research. Methods Using the example of cortical cataract detection, we developed an algorithm for assisting a reviewer in evaluating digital images for the presence and severity of lesions. Available image processing and statistical methods that were easily implementable were used as the basis for the CAD algorithm. The performance of the system was compared to the subjective assessment of five reviewers using 60 simulated images. Cortical cataract severity scores from 0 to 16 were assigned to the images by the reviewers and the CAD system, with each image assessed twice to obtain a measure of variability. Image characteristics that affected reviewer bias were also assessed by systematically varying the appearance of the simulated images. Results The algorithm yielded severity scores with smaller bias on images where cataract severity was mild to moderate (approximately ≤ 6/16ths. On high severity images, the bias of the CAD system exceeded that of the reviewers. The variability of the CAD system was zero on repeated images but ranged from 0.48 to 1.22 for the reviewers. The direction and magnitude of the bias exhibited by the reviewers was a function of the number of cataract opacities, the shape and the contrast of the lesions in the simulated images. Conclusion CAD systems are feasible to implement with available software and can be valuable when medical images contain exposure or outcome information for

  13. A review of computer-aided design/computer-aided manufacture techniques for removable denture fabrication

    Science.gov (United States)

    Bilgin, Mehmet Selim; Baytaroğlu, Ebru Nur; Erdem, Ali; Dilber, Erhan

    2016-01-01

    The aim of this review was to investigate usage of computer-aided design/computer-aided manufacture (CAD/CAM) such as milling and rapid prototyping (RP) technologies for removable denture fabrication. An electronic search was conducted in the PubMed/MEDLINE, ScienceDirect, Google Scholar, and Web of Science databases. Databases were searched from 1987 to 2014. The search was performed using a variety of keywords including CAD/CAM, complete/partial dentures, RP, rapid manufacturing, digitally designed, milled, computerized, and machined. The identified developments (in chronological order), techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication are summarized. Using a variety of keywords and aiming to find the topic, 78 publications were initially searched. For the main topic, the abstract of these 78 articles were scanned, and 52 publications were selected for reading in detail. Full-text of these articles was gained and searched in detail. Totally, 40 articles that discussed the techniques, advantages, and disadvantages of CAD/CAM and RP for removable denture fabrication and the articles were incorporated in this review. Totally, 16 of the papers summarized in the table. Following review of all relevant publications, it can be concluded that current innovations and technological developments of CAD/CAM and RP allow the digitally planning and manufacturing of removable dentures from start to finish. As a result according to the literature review CAD/CAM techniques and supportive maxillomandibular relationship transfer devices are growing fast. In the close future, fabricating removable dentures will become medical informatics instead of needing a technical staff and procedures. However the methods have several limitations for now. PMID:27095912

  14. Computer-aided design for metabolic engineering.

    Science.gov (United States)

    Fernández-Castané, Alfred; Fehér, Tamás; Carbonell, Pablo; Pauthenier, Cyrille; Faulon, Jean-Loup

    2014-12-20

    The development and application of biotechnology-based strategies has had a great socio-economical impact and is likely to play a crucial role in the foundation of more sustainable and efficient industrial processes. Within biotechnology, metabolic engineering aims at the directed improvement of cellular properties, often with the goal of synthesizing a target chemical compound. The use of computer-aided design (CAD) tools, along with the continuously emerging advanced genetic engineering techniques have allowed metabolic engineering to broaden and streamline the process of heterologous compound-production. In this work, we review the CAD tools available for metabolic engineering with an emphasis, on retrosynthesis methodologies. Recent advances in genetic engineering strategies for pathway implementation and optimization are also reviewed as well as a range of bionalytical tools to validate in silico predictions. A case study applying retrosynthesis is presented as an experimental verification of the output from Retropath, the first complete automated computational pipeline applicable to metabolic engineering. Applying this CAD pipeline, together with genetic reassembly and optimization of culture conditions led to improved production of the plant flavonoid pinocembrin. Coupling CAD tools with advanced genetic engineering strategies and bioprocess optimization is crucial for enhanced product yields and will be of great value for the development of non-natural products through sustainable biotechnological processes. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Progress in computer aided diagnosis for medical images by information technology

    International Nuclear Information System (INIS)

    Mekada, Yoshito

    2007-01-01

    This paper describes the history, present state and future view of computer aided diagnosis (CAD) based on processing, recognition and visualization of chest and abdominal images. A primitive feature of CAD is seen as early as in 1960's for lung cancer detection. Contemporarily, advances in medical imaging by CT, MRI, single photon emission computed tomography (SPECT) and positron emission tomography (PET) in multi-dimensions require doctors to read those vast information, where necessity of CAD is evident. At present, simultaneous CAD for multi-organs and multi-diseases is in progress, the interaction between images and medical doctors is leading to developing a newer system like virtual endoscopy, objective evaluation of CAD systems is necessary for its approval to authorities like fluorescein diacetate (FDA) with use of receiver operating characteristics analysis, and thus cooperation of medical and technological fields is more and more important. In future, CAD should be responsible for individual difference and for change in disease state, usable simultaneously for time and space, more recognized of its importance by doctors, and more useful in participation to therapeutic practice. (R.T.)

  16. The Effects of Computer-Aided Design Software on Engineering Students' Spatial Visualisation Skills

    Science.gov (United States)

    Kösa, Temel; Karakus, Fatih

    2018-01-01

    The purpose of this study was to determine the influence of computer-aided design (CAD) software-based instruction on the spatial visualisation skills of freshman engineering students in a computer-aided engineering drawing course. A quasi-experimental design was applied, using the Purdue Spatial Visualization Test-Visualization of Rotations…

  17. Computer-aided detection of lung nodules via 3D fast radial transform, scale space representation, and Zernike MIP classification.

    Science.gov (United States)

    Riccardi, Alessandro; Petkov, Todor Sergueev; Ferri, Gianluca; Masotti, Matteo; Campanini, Renato

    2011-04-01

    The authors presented a novel system for automated nodule detection in lung CT exams. The approach is based on (1) a lung tissue segmentation preprocessing step, composed of histogram thresholding, seeded region growing, and mathematical morphology; (2) a filtering step, whose aim is the preliminary detection of candidate nodules (via 3D fast radial filtering) and estimation of their geometrical features (via scale space analysis); and (3) a false positive reduction (FPR) step, comprising a heuristic FPR, which applies thresholds based on geometrical features, and a supervised FPR, which is based on support vector machines classification, which in turn, is enhanced by a feature extraction algorithm based on maximum intensity projection processing and Zernike moments. The system was validated on 154 chest axial CT exams provided by the lung image database consortium public database. The authors obtained correct detection of 71% of nodules marked by all radiologists, with a false positive rate of 6.5 false positives per patient (FP/patient). A higher specificity of 2.5 FP/patient was reached with a sensitivity of 60%. An independent test on the ANODE09 competition database obtained an overall score of 0.310. The system shows a novel approach to the problem of lung nodule detection in CT scans: It relies on filtering techniques, image transforms, and descriptors rather than region growing and nodule segmentation, and the results are comparable to those of other recent systems in literature and show little dependency on the different types of nodules, which is a good sign of robustness.

  18. CAD on personal computers

    International Nuclear Information System (INIS)

    Lee, Seong U; Cho, Cheol Ho; Ko, Il Du

    1990-02-01

    This book contains four studies of CAD on personal computers. The first thing is computer graphics in computer-aided design by Seong U Lee. The second thing is graphics primer and programming with Fortran by Seong U Lee. The third thing is application of Auto cad by Il Do Ko. The last thing is application of CAD in building construction design by Cheol Ho Cho.

  19. Studies on computer-aided diagnosis systems for chest radiographs and mammograms (in Japanese)

    International Nuclear Information System (INIS)

    Hara, Takeshi

    2001-01-01

    This thesis describes computer-aided diagnosis (CAD) systems for chest radiographs and mammograms. Preprocessing and imaging processing methods for each CAD system include dynamic range compression and region segmentation technique. A new pattern recognition technique combines genetic algorithms with template matching methods to detect lung nodules. A genetic algorithm was employed to select the optimal shape of simulated nodular shadows to be compared with real lesions on digitized chest images. Detection performance was evaluated using 332 chest radiographs from the database of the Japanese Society of Radiological Technology. Our average true-positive rate was 72.8% with an average of 11 false-positive findings per image. A new detection method using high resolution digital images with 0.05 mm sampling is also proposed for the mammogram CAD system to detect very small microcalcifications. An automated classification method uses feature extraction based on fractal dimension analysis of masses. Using over 200 cases to evaluate the detection of mammographic masses and calcifications, the detection rate of masses and microcalcifications were 87% and 96% with 1.5 and 1.8 false-positive findings, respectively. The classification performance on benign vs malignant lesions, the Az values that were defined by the areas under the ROC curves derived from classification schemes of masses and microcalcifications were 0.84 and 0.89. To demonstrate the practicality of these CAD systems in a computer-network environment, we propose to use the mammogram CAD system via the Internet and WWW. A common gateway interface and server-client approach for the CAD system via the Internet will permit display of the CAD results on ordinary computers

  20. A new parameter enhancing breast cancer detection in computer-aided diagnosis of X-ray mammograms

    International Nuclear Information System (INIS)

    Tanki, Nobuyoshi; Murase, Kenya; Nagao, Michinobu

    2006-01-01

    The purpose of this study was to introduce a new parameter which enhances breast cancer detection using X-ray mammography. We used the database of X-ray mammograms generated by the Japan Society of Radiological Technology. The new parameter called 'quasi-fractal dimension (Q-FD)' was calculated from the relationship between the cutoff values for the maximum image intensity in the lesion set at 21 levels from 20% to 100% at equal intervals and the number of pixels with an intensity exceeding the cutoff value. In addition to Q-FD, the image features such as curvature (C) and eccentricity (E) were extracted. The conventional fractal dimension (C-FD) was also calculated using the box-counting method. We used artificial neural networks (ANNs) as a classification method. When using C, E, C-FD and age as inputs in ANNs and taking the number of neurons in the hidden layer as 50, we found the area under the receiver operating characteristic curve (A Z ) was 0.87±0.07 in the task differentiating between benign and malignant masses. When Q-FD was added to inputs in addition to the above parameters, the A Z value was significantly improved to become 0.93±0.09. These results suggested that Q-FD is effective for discriminating between benign and malignant masses. (author)

  1. A handheld computer-aided diagnosis system and simulated analysis

    Science.gov (United States)

    Su, Mingjian; Zhang, Xuejun; Liu, Brent; Su, Kening; Louie, Ryan

    2016-03-01

    This paper describes a Computer Aided Diagnosis (CAD) system based on cellphone and distributed cluster. One of the bottlenecks in building a CAD system for clinical practice is the storage and process of mass pathology samples freely among different devices, and normal pattern matching algorithm on large scale image set is very time consuming. Distributed computation on cluster has demonstrated the ability to relieve this bottleneck. We develop a system enabling the user to compare the mass image to a dataset with feature table by sending datasets to Generic Data Handler Module in Hadoop, where the pattern recognition is undertaken for the detection of skin diseases. A single and combination retrieval algorithm to data pipeline base on Map Reduce framework is used in our system in order to make optimal choice between recognition accuracy and system cost. The profile of lesion area is drawn by doctors manually on the screen, and then uploads this pattern to the server. In our evaluation experiment, an accuracy of 75% diagnosis hit rate is obtained by testing 100 patients with skin illness. Our system has the potential help in building a novel medical image dataset by collecting large amounts of gold standard during medical diagnosis. Once the project is online, the participants are free to join and eventually an abundant sample dataset will soon be gathered enough for learning. These results demonstrate our technology is very promising and expected to be used in clinical practice.

  2. IPAD II (Integrated Programs for Aerospace-Vehicle Design) Advances in Distributed Data Base Management for CAD/CAM (Computer-Aided Design and Manufacturing Technology). Proceedings of a National Symposium Held in Denver, Colorado, April 17-19, 1984.

    Science.gov (United States)

    1984-01-01

    et al. "DATANET/HERMES: Un Sistema Per La Gestione Di Basi Di Dati Distribuite", Annual Conference, A.I. C. A., Pavia, (September 1981). [9] Neuhold...to move to more sophisticated integrated CAD/CAM applications. A geometrically complete three-dimensional des - cription is required for such purposes...definitions and semantic constructs for these types of applications have achieved a de facto degree of standardization and normalization (a common and

  3. Evaluation of Five Microcomputer CAD Packages.

    Science.gov (United States)

    Leach, James A.

    1987-01-01

    Discusses the similarities, differences, advanced features, applications and number of users of five microcomputer computer-aided design (CAD) packages. Included are: "AutoCAD (V.2.17)"; "CADKEY (V.2.0)"; "CADVANCE (V.1.0)"; "Super MicroCAD"; and "VersaCAD Advanced (V.4.00)." Describes the…

  4. Optimization of Network Topology in Computer-Aided Detection Schemes Using Phased Searching with NEAT in a Time-Scaled Framework.

    Science.gov (United States)

    Tan, Maxine; Pu, Jiantao; Zheng, Bin

    2014-01-01

    In the field of computer-aided mammographic mass detection, many different features and classifiers have been tested. Frequently, the relevant features and optimal topology for the artificial neural network (ANN)-based approaches at the classification stage are unknown, and thus determined by trial-and-error experiments. In this study, we analyzed a classifier that evolves ANNs using genetic algorithms (GAs), which combines feature selection with the learning task. The classifier named "Phased Searching with NEAT in a Time-Scaled Framework" was analyzed using a dataset with 800 malignant and 800 normal tissue regions in a 10-fold cross-validation framework. The classification performance measured by the area under a receiver operating characteristic (ROC) curve was 0.856 ± 0.029. The result was also compared with four other well-established classifiers that include fixed-topology ANNs, support vector machines (SVMs), linear discriminant analysis (LDA), and bagged decision trees. The results show that Phased Searching outperformed the LDA and bagged decision tree classifiers, and was only significantly outperformed by SVM. Furthermore, the Phased Searching method required fewer features and discarded superfluous structure or topology, thus incurring a lower feature computational and training and validation time requirement. Analyses performed on the network complexities evolved by Phased Searching indicate that it can evolve optimal network topologies based on its complexification and simplification parameter selection process. From the results, the study also concluded that the three classifiers - SVM, fixed-topology ANN, and Phased Searching with NeuroEvolution of Augmenting Topologies (NEAT) in a Time-Scaled Framework - are performing comparably well in our mammographic mass detection scheme.

  5. The computer-aided design of rubber-metal products

    Directory of Open Access Journals (Sweden)

    Pavlo S. Shvets

    2015-12-01

    Full Text Available The important problem in design of rubber-metal products is the optimization of their mass without sacrificing of proportionality factor is in the limits of standard. Aim: The aim of this work is to improve the computer-aided systems by development and implementation of improved optimization method in rubber-metal CAD systems for designers based on the reverse optimization. Materials and Methods: The paper studies the matters of computer-aided structural design of technical composite products composed of anisotropic materials that are essentially different in properties. Results: The structure of CAD systems for designers solving the problems of such design is offered and the work principles of its subsystems are described. It is shown that complicated systems optimization in CAD systems must consider as restrictions the entitative connection between separate elements of these systems within the area of the optimizing arguments. Conclusions: The problem of the “reverse” optimization when objective functions are the connectivity area parameters is considered. In many cases, this allows receiving solutions that are more effective during the computer-aided design process. The developed CAD system for designers was used during the production of rubber-metal shock absorbers at the Odessa Rubber Technical Articles Plant. The positive technical and economic effect was obtained.

  6. Computer-aided diagnosis in radiological imaging: current status and future challenges

    Science.gov (United States)

    Doi, Kunio

    2009-10-01

    Computer-aided diagnosis (CAD) has become one of the major research subjects in medical imaging and diagnostic radiology. Many different types of CAD schemes are being developed for detection and/or characterization of various lesions in medical imaging, including conventional projection radiography, CT, MRI, and ultrasound imaging. Commercial systems for detection of breast lesions on mammograms have been developed and have received FDA approval for clinical use. CAD may be defined as a diagnosis made by a physician who takes into account the computer output as a "second opinion". The purpose of CAD is to improve the quality and productivity of physicians in their interpretation of radiologic images. The quality of their work can be improved in terms of the accuracy and consistency of their radiologic diagnoses. In addition, the productivity of radiologists is expected to be improved by a reduction in the time required for their image readings. The computer output is derived from quantitative analysis of radiologic images by use of various methods and techniques in computer vision, artificial intelligence, and artificial neural networks (ANNs). The computer output may indicate a number of important parameters, for example, the locations of potential lesions such as lung cancer and breast cancer, the likelihood of malignancy of detected lesions, and the likelihood of various diseases based on differential diagnosis in a given image and clinical parameters. In this review article, the basic concept of CAD is first defined, and the current status of CAD research is then described. In addition, the potential of CAD in the future is discussed and predicted.

  7. Development and clinical application of a computer-aided real-time feedback system for detecting in-bed physical activities.

    Science.gov (United States)

    Lu, Liang-Hsuan; Chiang, Shang-Lin; Wei, Shun-Hwa; Lin, Chueh-Ho; Sung, Wen-Hsu

    2017-08-01

    Being bedridden long-term can cause deterioration in patients' physiological function and performance, limiting daily activities and increasing the incidence of falls and other accidental injuries. Little research has been carried out in designing effective detecting systems to monitor the posture and status of bedridden patients and to provide accurate real-time feedback on posture. The purposes of this research were to develop a computer-aided system for real-time detection of physical activities in bed and to validate the system's validity and test-retest reliability in determining eight postures: motion leftward/rightward, turning over leftward/rightward, getting up leftward/rightward, and getting off the bed leftward/rightward. The in-bed physical activity detecting system consists mainly of a clinical sickbed, signal amplifier, a data acquisition (DAQ) system, and operating software for computing and determining postural changes associated with four load cell sensing components. Thirty healthy subjects (15 males and 15 females, mean age = 27.8 ± 5.3 years) participated in the study. All subjects were asked to execute eight in-bed activities in a random order and to participate in an evaluation of the test-retest reliability of the results 14 days later. Spearman's rank correlation coefficient was used to compare the system's determinations of postural states with researchers' recordings of postural changes. The test-retest reliability of the system's ability to determine postures was analyzed using the interclass correlation coefficient ICC(3,1). The system was found to exhibit high validity and accuracy (r = 0.928, p system was particularly accurate in detecting motion rightward (90%), turning over leftward (83%), sitting up leftward or rightward (87-93%), and getting off the bed (100%). The test-retest reliability ICC(3,1) value was 0.968 (p system developed in this study exhibits satisfactory validity and reliability in detecting changes in

  8. The VE/CAD synergism

    International Nuclear Information System (INIS)

    Sperling, R.B.

    1993-01-01

    Value Engineering (VE) and Computer-Aided Design (CAD) can be used synergistically to reduce costs and improve facilities designs. The cost and schedule impacts of implementing alternative design ideas developed by VE teams can be greatly reduced when the drawings have been produced with interactive CAD systems. To better understand the interrelationship between VE and CAD, the fundamentals of the VE process are explained; and example of a VE proposal is described and the way CAD drawings facilitated its implementation is illustrated

  9. Costs incurred by applying computer-aided design/computer-aided manufacturing techniques for the reconstruction of maxillofacial defects.

    Science.gov (United States)

    Rustemeyer, Jan; Melenberg, Alex; Sari-Rieger, Aynur

    2014-12-01

    This study aims to evaluate the additional costs incurred by using a computer-aided design/computer-aided manufacturing (CAD/CAM) technique for reconstructing maxillofacial defects by analyzing typical cases. The medical charts of 11 consecutive patients who were subjected to the CAD/CAM technique were considered, and invoices from the companies providing the CAD/CAM devices were reviewed for every case. The number of devices used was significantly correlated with cost (r = 0.880; p costs were found between cases in which prebent reconstruction plates were used (€3346.00 ± €29.00) and cases in which they were not (€2534.22 ± €264.48; p costs of two, three and four devices, even when ignoring the cost of reconstruction plates. Additional fees provided by statutory health insurance covered a mean of 171.5% ± 25.6% of the cost of the CAD/CAM devices. Since the additional fees provide financial compensation, we believe that the CAD/CAM technique is suited for wide application and not restricted to complex cases. Where additional fees/funds are not available, the CAD/CAM technique might be unprofitable, so the decision whether or not to use it remains a case-to-case decision with respect to cost versus benefit. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  10. Microwave processing of a dental ceramic used in computer-aided design/computer-aided manufacturing.

    Science.gov (United States)

    Pendola, Martin; Saha, Subrata

    2015-01-01

    Because of their favorable mechanical properties and natural esthetics, ceramics are widely used in restorative dentistry. The conventional ceramic sintering process required for their use is usually slow, however, and the equipment has an elevated energy consumption. Sintering processes that use microwaves have several advantages compared to regular sintering: shorter processing times, lower energy consumption, and the capacity for volumetric heating. The objective of this study was to test the mechanical properties of a dental ceramic used in computer-aided design/computer-aided manufacturing (CAD/CAM) after the specimens were processed with microwave hybrid sintering. Density, hardness, and bending strength were measured. When ceramic specimens were sintered with microwaves, the processing times were reduced and protocols were simplified. Hardness was improved almost 20% compared to regular sintering, and flexural strength measurements suggested that specimens were approximately 50% stronger than specimens sintered in a conventional system. Microwave hybrid sintering may preserve or improve the mechanical properties of dental ceramics designed for CAD/CAM processing systems, reducing processing and waiting times.

  11. Computer-aided dental prostheses construction using reverse engineering.

    Science.gov (United States)

    Solaberrieta, E; Minguez, R; Barrenetxea, L; Sierra, E; Etxaniz, O

    2014-01-01

    The implementation of computer-aided design/computer-aided manufacturing (CAD/CAM) systems with virtual articulators, which take into account the kinematics, constitutes a breakthrough in the construction of customised dental prostheses. This paper presents a multidisciplinary protocol involving CAM techniques to produce dental prostheses. This protocol includes a step-by-step procedure using innovative reverse engineering technologies to transform completely virtual design processes into customised prostheses. A special emphasis is placed on a novel method that permits a virtual location of the models. The complete workflow includes the optical scanning of the patient, the use of reverse engineering software and, if necessary, the use of rapid prototyping to produce CAD temporary prostheses.

  12. Computer-Aided Modeling Framework

    DEFF Research Database (Denmark)

    Fedorova, Marina; Sin, Gürkan; Gani, Rafiqul

    Models are playing important roles in design and analysis of chemicals based products and the processes that manufacture them. Computer-aided methods and tools have the potential to reduce the number of experiments, which can be expensive and time consuming, and there is a benefit of working...... development and application. The proposed work is a part of the project for development of methods and tools that will allow systematic generation, analysis and solution of models for various objectives. It will use the computer-aided modeling framework that is based on a modeling methodology, which combines....... In this contribution, the concept of template-based modeling is presented and application is highlighted for the specific case of catalytic membrane fixed bed models. The modeling template is integrated in a generic computer-aided modeling framework. Furthermore, modeling templates enable the idea of model reuse...

  13. Analysis and minimization of overtraining effect in rule-based classifiers for computer-aided diagnosis

    International Nuclear Information System (INIS)

    Li Qiang; Doi Kunio

    2006-01-01

    Computer-aided diagnostic (CAD) schemes have been developed to assist radiologists detect various lesions in medical images. In CAD schemes, classifiers play a key role in achieving a high lesion detection rate and a low false-positive rate. Although many popular classifiers such as linear discriminant analysis and artificial neural networks have been employed in CAD schemes for reduction of false positives, a rule-based classifier has probably been the simplest and most frequently used one since the early days of development of various CAD schemes. However, with existing rule-based classifiers, there are major disadvantages that significantly reduce their practicality and credibility. The disadvantages include manual design, poor reproducibility, poor evaluation methods such as resubstitution, and a large overtraining effect. An automated rule-based classifier with a minimized overtraining effect can overcome or significantly reduce the extent of the above-mentioned disadvantages. In this study, we developed an 'optimal' method for the selection of cutoff thresholds and a fully automated rule-based classifier. Experimental results performed with Monte Carlo simulation and a real lung nodule CT data set demonstrated that the automated threshold selection method can completely eliminate overtraining effect in the procedure of cutoff threshold selection, and thus can minimize overall overtraining effect in the constructed rule-based classifier. We believe that this threshold selection method is very useful in the construction of automated rule-based classifiers with minimized overtraining effect

  14. Dual-scan technique for the customization of zirconia computer-aided design/computer-aided manufacturing frameworks.

    Science.gov (United States)

    Andreiuolo, Rafael Ferrone; Sabrosa, Carlos Eduardo; Dias, Katia Regina H Cervantes

    2013-09-01

    The use of bi-layered all-ceramic crowns has continuously grown since the introduction of computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia cores. Unfortunately, despite the outstanding mechanical properties of zirconia, problems related to porcelain cracking or chipping remain. One of the reasons for this is that ceramic copings are usually milled to uniform thicknesses of 0.3-0.6 mm around the whole tooth preparation. This may not provide uniform thickness or appropriate support for the veneering porcelain. To prevent these problems, the dual-scan technique demonstrates an alternative that allows the restorative team to customize zirconia CAD/CAM frameworks with adequate porcelain thickness and support in a simple manner.

  15. Computer-aided classification of breast masses using contrast-enhanced digital mammograms

    Science.gov (United States)

    Danala, Gopichandh; Aghaei, Faranak; Heidari, Morteza; Wu, Teresa; Patel, Bhavika; Zheng, Bin

    2018-02-01

    By taking advantages of both mammography and breast MRI, contrast-enhanced digital mammography (CEDM) has emerged as a new promising imaging modality to improve efficacy of breast cancer screening and diagnosis. The primary objective of study is to develop and evaluate a new computer-aided detection and diagnosis (CAD) scheme of CEDM images to classify between malignant and benign breast masses. A CEDM dataset consisting of 111 patients (33 benign and 78 malignant) was retrospectively assembled. Each case includes two types of images namely, low-energy (LE) and dual-energy subtracted (DES) images. First, CAD scheme applied a hybrid segmentation method to automatically segment masses depicting on LE and DES images separately. Optimal segmentation results from DES images were also mapped to LE images and vice versa. Next, a set of 109 quantitative image features related to mass shape and density heterogeneity was initially computed. Last, four multilayer perceptron-based machine learning classifiers integrated with correlationbased feature subset evaluator and leave-one-case-out cross-validation method was built to classify mass regions depicting on LE and DES images, respectively. Initially, when CAD scheme was applied to original segmentation of DES and LE images, the areas under ROC curves were 0.7585+/-0.0526 and 0.7534+/-0.0470, respectively. After optimal segmentation mapping from DES to LE images, AUC value of CAD scheme significantly increased to 0.8477+/-0.0376 (pbreast tissue on lesions, segmentation accuracy was significantly improved as compared to regular mammograms, the study demonstrated that computer-aided classification of breast masses using CEDM images yielded higher performance.

  16. Fracture resistance of computer-aided design and computer-aided manufacturing ceramic crowns cemented on solid abutments.

    Science.gov (United States)

    Stona, Deborah; Burnett, Luiz Henrique; Mota, Eduardo Gonçalves; Spohr, Ana Maria

    2015-07-01

    Because no information was found in the dental literature regarding the fracture resistance of all-ceramic crowns using CEREC (Sirona) computer-aided design and computer-aided manufacturing (CAD-CAM) system on solid abutments, the authors conducted a study. Sixty synOcta (Straumann) implant replicas and regular neck solid abutments were embedded in acrylic resin and randomly assigned (n = 20 per group). Three types of ceramics were used: feldspathic, CEREC VITABLOCS Mark II (VITA); leucite, IPS Empress CAD (Ivoclar Vivadent); and lithium disilicate, IPS e.max CAD (Ivoclar Vivadent). The crowns were fabricated by the CEREC CAD-CAM system. After receiving glaze, the crowns were cemented with RelyX U200 (3M ESPE) resin cement under load of 1 kilogram. For each ceramic, one-half of the specimens were subjected to the fracture resistance testing in a universal testing machine with a crosshead speed of 1 millimeter per minute, and the other half were subjected to the fractured resistance testing after 1,000,000 cyclic fatigue loading at 100 newtons. According to a 2-way analysis of variance, the interaction between the material and mechanical cycling was significant (P = .0001). According to a Tukey test (α = .05), the fracture resistance findings with or without cyclic fatigue loading were as follows, respectively: CEREC VITABLOCKS Mark II (405 N/454 N) was statistically lower than IPS Empress CAD (1169 N/1240 N) and IPS e.max CAD (1378 N/1025 N) (P Empress CAD and IPS e.max CAD did not differ statistically (P > .05). According to a t test, there was no statistical difference in the fracture resistance with and without cyclic fatigue loading for CEREC VITABLOCS Mark II and IPS Empress CAD (P > .05). For IPS e.max CAD, the fracture resistance without cyclic fatigue loading was statistically superior to that obtained with cyclic fatigue loading (P Empress CAD and IPS e.max CAD showed higher fracture resistance compared with CEREC VITABLOCS Mark II. The cyclic

  17. Computer-aided cleanup

    International Nuclear Information System (INIS)

    Williams, J.; Jones, B.

    1994-01-01

    In late 1992, the remedial investigation of operable unit 2 at the Department of Energy (DOE) Superfund site in Fernald, Ohio was in trouble. Despite years of effort--including an EPA-approved field-investigation work plan, 123 soil borings, 51 ground-water-monitoring wells, analysis of more than 650 soil and ground-water samples, and preparation of a draft remedial-investigation (RI) report--it was not possible to conclude if contaminated material in the unit was related to ground-water contamination previously detected beneath and beyond the site boundary. Compounding the problem, the schedule for the RI, feasibility study and record of decision for operable unit 2 was governed by a DOE-EPA consent agreement stipulating penalties of up to $10,000 per week for not meeting scheduled milestones--and time was running out. An advanced three-dimensional computer model confirmed that radioactive wastes dumped at the Fernald, Ohio Superfund site had contaminated ground water, after years of previous testing has been inconclusive. The system is now being used to aid feasibility and design work on the more-than-$1 billion remediation project

  18. Computer-Aided Diagnosis of Different Rotator Cuff Lesions Using Shoulder Musculoskeletal Ultrasound.

    Science.gov (United States)

    Chang, Ruey-Feng; Lee, Chung-Chien; Lo, Chung-Ming

    2016-09-01

    The lifetime prevalence of shoulder pain approaches 70%, which is mostly attributable to rotator cuff lesions such as inflammation, calcific tendinitis and tears. On clinical examination, shoulder ultrasound is recommended for the detection of lesions. However, there exists inter-operator variability in diagnostic accuracy because of differences in the experience and expertise of operators. In this study, a computer-aided diagnosis (CAD) system was developed to assist ultrasound operators in diagnosing rotator cuff lesions and to improve the practicality of ultrasound examination. The collected cases included 43 cases of inflammation, 30 cases of calcific tendinitis and 26 tears. For each case, the lesion area and texture features were extracted from the entire lesions and combined in a multinomial logistic regression classifier for lesion classification. The proposed CAD achieved an accuracy of 87.9%. The individual accuracy of this CAD system was 88.4% for inflammation, 83.3% for calcific tendinitis and 92.3% for tears. Cohen's k was 0.798. On the basis of its diagnostic performance, clinical use of this CAD technique has promise. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  19. Virtual colonoscopy: effect of computer-assisted detection (CAD) on radiographer performance

    International Nuclear Information System (INIS)

    Burling, D.; Moore, A.; Marshall, M.; Weldon, J.; Gillen, C.; Baldwin, R.; Smith, K.; Pickhardt, P.; Honeyfield, L.; Taylor, S.

    2008-01-01

    Aim: To investigate the effect of a virtual colonoscopy (VC) computed-assisted detection (CAD) system on polyp detection by trained radiographers. Materials and methods: Four radiographers trained in VC interpretation and utilization of CAD systems read a total of 62 endoscopically validated VC examinations containing 150 polyps (size range 5-50 mm) in four sessions, recording any polyps found and the examination interpretation time, first without and then with the addition of CAD as a 'second reader'. After a temporal separation of 6 weeks to reduce recall bias, VC examinations were re-read using 'concurrent reader' CAD. Interpretation times, polyp detection, and number of false-positives were compared between the different reader paradigms using paired t and paired exact tests. Results: Overall, use of 'second reader' CAD significantly improved polyp detection by 12% (p < 0.001, CI 6%,17%)) from 48 to 60%. There was no significant improvement using CAD as a concurrent reader (p = 0.20; difference of 7%, CI -3%, 16%) and no significant overall difference in recorded false-positives with second reader or concurrent CAD paradigms compared with unassisted reading (p = 0.25 and 0.65, respectively). The mean interpretation time was 21.7 min for unassisted reading, 29.6 (p < 0.001) min for second reader and 19.1 min (p = 0.12) for concurrent reading paradigms. Conclusion: CAD, when used as a second reader, can significantly improve radiographer reading performance with only a moderate increase in interpretation times

  20. Computer Aided Design i England

    DEFF Research Database (Denmark)

    Sigrist, F.; Agger, K.; Barfoed, P.

    Meddelelsen redegør for en række besøg hos engelske systemleverandører og brugere. Seks forskellige CAD-systemer vurderes på baggrund af deres brug i praksis, og valget af to systemer til afprøvning i Danmark begrundes. Desuden bringes generelle konklusioner om CAD-systemernes aktuelle udviklings...

  1. Computer Aided Design i Danmark

    DEFF Research Database (Denmark)

    Sigrist, F.; Barfoed, P; Henriksen, L.

    Rapporten beskriver sidste fase i et projekt, som sigter mod at opbygge erfaringer om brug af CAD på danske tegnestuer. På en studietur valgte tre tegnestuer hver et CAD-system til afprøvning i fire måneder. Rapporten redegør for erfaringerne og belyser forholdet mellem dansk byggeri og datatekni...

  2. Computer-aided system for cryogenic research facilities

    International Nuclear Information System (INIS)

    Gerasimov, V.P.; Zhelamsky, M.V.; Mozin, I.V.; Repin, S.S.

    1994-01-01

    A computer-aided system is developed for the more effective choice and optimization of the design and manufacturing technologies of the superconductor for the magnet system of the International Thermonuclear Experimental Reactor (ITER) with the aim to ensure the superconductor certification. The computer-aided system provides acquisition, processing, storage and display of data describing the proceeding tests, the detection of any parameter deviations and their analysis. Besides, it generates commands for the equipment switch off in emergency situations. ((orig.))

  3. 1000-Case Reader Study of Radiologists' Performance in Interpretation of Automated Breast Volume Scanner Images with a Computer-Aided Detection System.

    Science.gov (United States)

    Xu, Xiaojing; Bao, Lingyun; Tan, Yanjuan; Zhu, Luoxi; Kong, Fanlei; Wang, Wei

    2018-05-28

    The objective of our study was to assess, in a reader study, radiologists' performance in interpretation of automated breast volume scanner (ABVS) images with the aid of a computer-aided detection (CADe) system. Our study is a retrospective observer study with the purpose of investigating the effectiveness of using a CADe system as an aid for radiologists in interpretation of ABVS images. The multiple-reader, multiple-case study was designed to compare the diagnostic performance of radiologists with and without CADe. The study included 1000 cases selected from ABVS examinations in our institution in 2012. Among those cases were 206 malignant, 486 benign and 308 normal cases. The cancer cases were consecutive; the benign and normal cases were randomly selected. All malignant and benign cases were confirmed by biopsy or surgery, and normal cases were confirmed by 2-y follow-up. Reader performance was compared in terms of area under the receiver operating characteristic curve, sensitivity and specificity. Additionally, the reading time per case for each reader was recorded. Nine radiologists from our institution participated in the study. Three had more than 8 y of ultrasound experience and more than 4 y of ABVS experience (group A); 3 had more than 5 y of ultrasound experience (group B), and 3 had more than 1 y of ultrasound experience (group C). Both group B and group C had no ABVS experience. The CADe system used was the QVCAD System (QView Medical, Inc., Los Altos, CA, USA). It is designed to aid radiologists in searching for suspicious areas in ABVS images. CADe results are presented to the reader simultaneously with the ABVS images; that is, the radiologists read the ABVS images concurrently with the CADe results. The cases were randomly assigned for each reader into two equal-size groups, 1 and 2. Initially the readers read their group 1 cases with the aid of CADe and their group 2 cases without CADe. After a 1-mo washout period, they re-read their group 1

  4. Computer-Aided Parts Estimation

    OpenAIRE

    Cunningham, Adam; Smart, Robert

    1993-01-01

    In 1991, Ford Motor Company began deployment of CAPE (computer-aided parts estimating system), a highly advanced knowledge-based system designed to generate, evaluate, and cost automotive part manufacturing plans. cape is engineered on an innovative, extensible, declarative process-planning and estimating knowledge representation language, which underpins the cape kernel architecture. Many manufacturing processes have been modeled to date, but eventually every significant process in motor veh...

  5. Computer aids for plant operators

    International Nuclear Information System (INIS)

    Joly, J.P.

    1992-01-01

    For some time, particularly since the TMI accident, nuclear power plant operators have been aware of the difficulties involved in diagnosing accidents and returning plants to their stable, safe operating mode. There are various possible solutions to these problems: improve control organization during accident situations, rewrite control procedures, integrate safety engineers in shifts, improve control rooms, and implement additional computer aids. The purpose of this presentation is to describe the efforts undertaken by EDF over the last few years in this field

  6. [Computer aided design for fixed partial denture framework based on reverse engineering technology].

    Science.gov (United States)

    Sun, Yu-chun; Lü, Pei-jun; Wang, Yong

    2006-03-01

    To explore a computer aided design (CAD) route for the framework of domestic fixed partial denture (FPD) and confirm the suitable method of 3-D CAD. The working area of a dentition model was scanned with a 3-D mechanical scanner. Using the reverse engineering (RE) software, margin and border curves were extracted and several reference curves were created to ensure the dimension and location of pontic framework that was taken from the standard database. The shoulder parts of the retainers were created after axial surfaces constructed. The connecting areas, axial line and curving surface of the framework connector were finally created. The framework of a three-unit FPD was designed with RE technology, which showed smooth surfaces and continuous contours. The design route is practical. The result of this study is significant in theory and practice, which will provide a reference for establishing the computer aided design/computer aided manufacture (CAD/CAM) system of domestic FPD.

  7. Development of the computer-aided process planning (CAPP system for polymer injection molds manufacturing

    Directory of Open Access Journals (Sweden)

    J. Tepić

    2011-10-01

    Full Text Available Beginning of production and selling of polymer products largely depends on mold manufacturing. The costs of mold manufacturing have significant share in the final price of a product. The best way to improve and rationalize polymer injection molds production process is by doing mold design automation and manufacturing process planning automation. This paper reviews development of a dedicated process planning system for manufacturing of the mold for injection molding, which integrates computer-aided design (CAD, computer-aided process planning (CAPP and computer-aided manufacturing (CAM technologies.

  8. Computer-Aided Facilities Management Systems (CAFM).

    Science.gov (United States)

    Cyros, Kreon L.

    Computer-aided facilities management (CAFM) refers to a collection of software used with increasing frequency by facilities managers. The six major CAFM components are discussed with respect to their usefulness and popularity in facilities management applications: (1) computer-aided design; (2) computer-aided engineering; (3) decision support…

  9. Computer aided design (CAD) for electronics improvement of the nuclear channels of TRIGA Mark III reactor of the ININ; Diseno asistido por computadora (DAC) para mejorar la electronica de los canales nucleares del reactor TRIGA Mark III del ININ

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, J.L.; Rivero G, T.; Aguilar H, F. [ININ, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: jlgm@nuclear.inin.mx

    2007-07-01

    The 4 neutron measurement channels of the digital control console (CCD) of the TRIGA Mark III reactor (RTMIII) of the ININ, its were designed and built with the corresponding Quality Guarantee program, being achieved the one licensing to replace the old console. With the time they were carried out some changes to improve and to not solve some problems detected in the tests, verification and validation, requiring to modify the circuits originally designed. In this work the corrective actions carried out to eliminate the Non Conformity generated by these problems, being mentioned the advantages of using modern tools, as the software applied to the Attended Engineering by Computer, and those obtained results are presented. (Author)

  10. CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) Highlights.

    Science.gov (United States)

    1984-10-01

    ATTN: AMCRE-C/Ms. Jean Lamb C dr, ATTN: ANCRM-P/Mr. Jerry Gibson Cdr, ATTN: AMCQA-E/Mr. Billings Cdr, ATTN: AMXAM-TL/Technical Library US Army...Sands Missile Range, ATTN: STEWS -TE-TL/Technical Library Cdr, US Military Academy, ATTN: LTC Lanse Leach - - . Cdr, Yuma Proving Grounds, ATTN

  11. Machine learning techniques for breast cancer computer aided diagnosis using different image modalities: A systematic review.

    Science.gov (United States)

    Yassin, Nisreen I R; Omran, Shaimaa; El Houby, Enas M F; Allam, Hemat

    2018-03-01

    The high incidence of breast cancer in women has increased significantly in the recent years. Physician experience of diagnosing and detecting breast cancer can be assisted by using some computerized features extraction and classification algorithms. This paper presents the conduction and results of a systematic review (SR) that aims to investigate the state of the art regarding the computer aided diagnosis/detection (CAD) systems for breast cancer. The SR was conducted using a comprehensive selection of scientific databases as reference sources, allowing access to diverse publications in the field. The scientific databases used are Springer Link (SL), Science Direct (SD), IEEE Xplore Digital Library, and PubMed. Inclusion and exclusion criteria were defined and applied to each retrieved work to select those of interest. From 320 studies retrieved, 154 studies were included. However, the scope of this research is limited to scientific and academic works and excludes commercial interests. This survey provides a general analysis of the current status of CAD systems according to the used image modalities and the machine learning based classifiers. Potential research studies have been discussed to create a more objective and efficient CAD systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Evaluation of Shipbuilding CAD/CAM/CIM Systems - Phase II (Requirements for Future Systems)

    National Research Council Canada - National Science Library

    Horvath, John; Ross, Jonathan M

    1997-01-01

    .... The purpose of the analysis was two fold: 1. To describe the requirements of a competitive, future-oriented computer-aided design/computer-aided manufacturing/computer-integrated management (CAD/CAMYCIM...

  13. Computer-aided translation tools

    DEFF Research Database (Denmark)

    Christensen, Tina Paulsen; Schjoldager, Anne

    2016-01-01

    in Denmark is rather high in general, but limited in the case of machine translation (MT) tools: While most TSPs use translation-memory (TM) software, often in combination with a terminology management system (TMS), only very few have implemented MT, which is criticised for its low quality output, especially......The paper reports on a questionnaire survey from 2013 of the uptake and use of computer-aided translation (CAT) tools by Danish translation service providers (TSPs) and discusses how these tools appear to have impacted on the Danish translation industry. According to our results, the uptake...

  14. Energy-aware memory management for embedded multimedia systems a computer-aided design approach

    CERN Document Server

    Balasa, Florin

    2011-01-01

    Energy-Aware Memory Management for Embedded Multimedia Systems: A Computer-Aided Design Approach presents recent computer-aided design (CAD) ideas that address memory management tasks, particularly the optimization of energy consumption in the memory subsystem. It explains how to efficiently implement CAD solutions, including theoretical methods and novel algorithms. The book covers various energy-aware design techniques, including data-dependence analysis techniques, memory size estimation methods, extensions of mapping approaches, and memory banking approaches. It shows how these techniques

  15. Microcomputer Simulated CAD for Engineering Graphics.

    Science.gov (United States)

    Huggins, David L.; Myers, Roy E.

    1983-01-01

    Describes a simulated computer-aided-graphics (CAD) program at The Pennsylvania State University. Rationale for the program, facilities, microcomputer equipment (Apple) used, and development of a software package for simulating applied engineering graphics are considered. (JN)

  16. Evaluation of the specificity of radionuclide myocardial imaging for detecting CAD

    International Nuclear Information System (INIS)

    Liu Xiujie

    1992-01-01

    In order to evaluate the specificity of radionuclide myocardial perfusion imaging for detecting coronary artery disease (CAD), 50 patients with normal coronary arteriography and radionuclide myocardial perfusion scintigraphy were analysed. The results from 201 T1 (20 cases) and 99m Tc-MIBI (30 cases) studies showed that out of 33 patients with no organic cardiovascular disease, 29 had normal myocardial imaging, and the specificity of radionuclide myocardial imaging for detecting CAD was 87.8%. 4 normal young women had false positive myocardial imaging. Out of 17 patients with cardiovascular disease and normal coronary arteriography, 15 patients had abnormal myocardial imaging. The final clinical diagnoses of these 15 patients were: 4 patients with hypertrophic cardiomyopathy, 3 with old myocardial infarction, 2 with myocarditis, 3 with small coronary vessel disease, 1 with congestive cardiomyopathy, and 2 with other cardiac disorder. The points of differentiation between CAD and other cardiovascular disease using radionuclide techniques were discussed

  17. Intelligent Embedded Instruction for Computer-Aided Design (CAD) systems

    Science.gov (United States)

    1988-10-01

    difficulties were predicted and six lessons were prepared that were aimed at preventing error pattern formation. The lessons were programmed in AUTOLISP ...and arcs, angles of lines, layering (linetype and color), and block creation and insertion. A program written in AUTOLISP examined the values in the

  18. Computer Aided Design in England

    DEFF Research Database (Denmark)

    Grau, K.(red.); Sigrist, F.(red.)

    Meddelelsen, der er på engelsk, bringer i fortsættelse af SBI-meddelelse 41 redigerede uddrag af leverandørernes introduktionsmateriale til seks CAD-systemer. Materialet indeholder værdifulde redegørelser for systemernes principielle opbygning og deres praktiske funktion og ydeevne....

  19. Computer aided system for parametric design of combination die

    Science.gov (United States)

    Naranje, Vishal G.; Hussein, H. M. A.; Kumar, S.

    2017-09-01

    In this paper, a computer aided system for parametric design of combination dies is presented. The system is developed using knowledge based system technique of artificial intelligence. The system is capable to design combination dies for production of sheet metal parts having punching and cupping operations. The system is coded in Visual Basic and interfaced with AutoCAD software. The low cost of the proposed system will help die designers of small and medium scale sheet metal industries for design of combination dies for similar type of products. The proposed system is capable to reduce design time and efforts of die designers for design of combination dies.

  20. Efficient Use of Preisach Hysteresis Model in Computer Aided Design

    Directory of Open Access Journals (Sweden)

    IONITA, V.

    2013-05-01

    Full Text Available The paper presents a practical detailed analysis regarding the use of the classical Preisach hysteresis model, covering all the steps, from measuring the necessary data for the model identification to the implementation in a software code for Computer Aided Design (CAD in Electrical Engineering. An efficient numerical method is proposed and the hysteresis modeling accuracy is tested on magnetic recording materials. The procedure includes the correction of the experimental data, which are used for the hysteresis model identification, taking into account the demagnetizing effect for the sample that is measured in an open-circuit device (a vibrating sample magnetometer.

  1. Computer aided analysis of disturbances

    International Nuclear Information System (INIS)

    Baldeweg, F.; Lindner, A.

    1986-01-01

    Computer aided analysis of disturbances and the prevention of failures (diagnosis and therapy control) in technological plants belong to the most important tasks of process control. Research in this field is very intensive due to increasing requirements to security and economy of process control and due to a remarkable increase of the efficiency of digital electronics. This publication concerns with analysis of disturbances in complex technological plants, especially in so called high risk processes. The presentation emphasizes theoretical concept of diagnosis and therapy control, modelling of the disturbance behaviour of the technological process and the man-machine-communication integrating artificial intelligence methods, e.g., expert system approach. Application is given for nuclear power plants. (author)

  2. Computer-aided instruction system

    International Nuclear Information System (INIS)

    Teneze, Jean Claude

    1968-01-01

    This research thesis addresses the use of teleprocessing and time sharing by the RAX IBM system and the possibility to introduce a dialog with the machine to develop an application in which the computer plays the role of a teacher for different pupils at the same time. Two operating modes are thus exploited: a teacher-mode and a pupil-mode. The developed CAI (computer-aided instruction) system comprises a checker to check the course syntax in teacher-mode, a translator to trans-code the course written in teacher-mode into a form which can be processes by the execution programme, and the execution programme which presents the course in pupil-mode

  3. Computer aided safety analysis 1989

    International Nuclear Information System (INIS)

    1990-04-01

    The meeting was conducted in a workshop style, to encourage involvement of all participants during the discussions. Forty-five (45) experts from 19 countries, plus 22 experts from the GDR participated in the meeting. A list of participants can be found at the end of this volume. Forty-two (42) papers were presented and discussed during the meeting. Additionally an open discussion was held on the possible directions of the IAEA programme on Computer Aided Safety Analysis. A summary of the conclusions of these discussions is presented in the publication. The remainder of this proceedings volume comprises the transcript of selected technical papers (22) presented in the meeting. It is the intention of the IAEA that the publication of these proceedings will extend the benefits of the discussions held during the meeting to a larger audience throughout the world. The Technical Committee/Workshop on Computer Aided Safety Analysis was organized by the IAEA in cooperation with the National Board for Safety and Radiological Protection (SAAS) of the German Democratic Republic in Berlin. The purpose of the meeting was to provide an opportunity for discussions on experiences in the use of computer codes used for safety analysis of nuclear power plants. In particular it was intended to provide a forum for exchange of information among experts using computer codes for safety analysis under the Technical Cooperation Programme on Safety of WWER Type Reactors (RER/9/004) and other experts throughout the world. A separate abstract was prepared for each of the 22 selected papers. Refs, figs tabs and pictures

  4. Modelling physics detectors in a computer aided design system for simulation purposes

    International Nuclear Information System (INIS)

    Ahvenainen, J.; Oksakivi, T.; Vuoskoski, J.

    1995-01-01

    The possibility of transferring physics detector models from computer aided design systems into physics simulation packages like GEANT is receiving increasing attention. The problem of exporting detector models constructed in CAD systems into GEANT is well known. We discuss the problem and describe an application, called DDT, which allows one to design detector models in a CAD system and then transfer the models into GEANT for simulation purposes. (orig.)

  5. Computer- Aided Design in Power Engineering Application of Software Tools

    CERN Document Server

    Stojkovic, Zlatan

    2012-01-01

    This textbooks demonstrates the application of software tools in solving a series of problems from the field of designing power system structures and systems. It contains four chapters: The first chapter leads the reader through all the phases necessary in the procedures of computer aided modeling and simulation. It guides through the complex problems presenting on the basis of eleven original examples. The second chapter presents  application of software tools in power system calculations of power systems equipment design. Several design example calculations are carried out using engineering standards like MATLAB, EMTP/ATP, Excel & Access, AutoCAD and Simulink. The third chapters focuses on the graphical documentation using a collection of software tools (AutoCAD, EPLAN, SIMARIS SIVACON, SIMARIS DESIGN) which enable the complete automation of the development of graphical documentation of a power systems. In the fourth chapter, the application of software tools in the project management in power systems ...

  6. [Veneer computer aided design based on reverse engineering technology].

    Science.gov (United States)

    Liu, Ming-li; Chen, Xiao-dong; Wang, Yong

    2012-03-01

    To explore the computer aided design (CAD) method of veneer restoration, and to assess if the solution can help prosthesis meet morphology esthetics standard. A volunteer's upper right central incisor needed to be restored with veneer. Super hard stone models of patient's dentition (before and after tooth preparation) were scanned with the three-dimensional laser scanner. The veneer margin was designed as butt-to-butt type. The veneer was constructed using reverse engineering (RE) software. The technique guideline of veneers CAD was explore based on RE software, and the veneers was smooth, continuous and symmetrical, which met esthetics construction needs. It was a feasible method to reconstruct veneer restoration based on RE technology.

  7. Computer Aided Design of Kaplan Turbine Piston with\tSolidWorks

    Directory of Open Access Journals (Sweden)

    Camelia Jianu

    2010-10-01

    Full Text Available The paper presents the steps for 3D computer aided design (CAD of Kaplan turbine piston made in SolidWorks.The present paper is a tutorial for a Kaplan turbine piston 3D geometry, which is dedicaded to the Parts Sketch and Parts Features design and Drawing Geometry and Drawing Annotation.

  8. Computer Aided Design of Kaplan Turbine Piston with SolidWorks

    OpenAIRE

    Camelia Jianu

    2010-01-01

    The paper presents the steps for 3D computer aided design (CAD) of Kaplan turbine piston made in SolidWorks.The present paper is a tutorial for a Kaplan turbine piston 3D geometry, which is dedicaded to the Parts Sketch and Parts Features design and Drawing Geometry and Drawing Annotation.

  9. CONTRIBUTIONS FOR DEVELOPING OF A COMPUTER AIDED LEARNING ENVIRONMENT OF DESCRIPTIVE GEOMETRY

    Directory of Open Access Journals (Sweden)

    Antonescu Ion

    2009-07-01

    Full Text Available The paper presents the authors’ contributions for developing a computer code for teaching of descriptive geometry using the computer aided learning techniques. The program was implemented using the programming interface and the 3D modeling capabilities of the AutoCAD system.

  10. AutoCAD 2010 For Dummies

    CERN Document Server

    Byrnes, David

    2009-01-01

    AutoCAD is the hot computer-aided design software known for both its powerful tools and its complexity. AutoCAD 2010 for Dummies is the bestselling guide that walks you through this complicated program so you can build complex 3D technical drawings, edit like a pro, enter new dimensions, and plot with style. AutoCAD 2010 for Dummies helps you navigate the program, use the AutoCAD Design Center, create a basic layout and work with dimension, and put your drawings on the Internet. You'll soon be setting up the AutoCAD environment, using the AutoCAD Ribbon, creating annotation and dimension drawi

  11. Computer Aided Battery Engineering Consortium

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, Ahmad

    2016-06-07

    A multi-national lab collaborative team was assembled that includes experts from academia and industry to enhance recently developed Computer-Aided Battery Engineering for Electric Drive Vehicles (CAEBAT)-II battery crush modeling tools and to develop microstructure models for electrode design - both computationally efficient. Task 1. The new Multi-Scale Multi-Domain model framework (GH-MSMD) provides 100x to 1,000x computation speed-up in battery electrochemical/thermal simulation while retaining modularity of particles and electrode-, cell-, and pack-level domains. The increased speed enables direct use of the full model in parameter identification. Task 2. Mechanical-electrochemical-thermal (MECT) models for mechanical abuse simulation were simultaneously coupled, enabling simultaneous modeling of electrochemical reactions during the short circuit, when necessary. The interactions between mechanical failure and battery cell performance were studied, and the flexibility of the model for various batteries structures and loading conditions was improved. Model validation is ongoing to compare with test data from Sandia National Laboratories. The ABDT tool was established in ANSYS. Task 3. Microstructural modeling was conducted to enhance next-generation electrode designs. This 3- year project will validate models for a variety of electrodes, complementing Advanced Battery Research programs. Prototype tools have been developed for electrochemical simulation and geometric reconstruction.

  12. Computer aided fault tree synthesis

    International Nuclear Information System (INIS)

    Poucet, A.

    1983-01-01

    Nuclear as well as non-nuclear organisations are showing during the past few years a growing interest in the field of reliability analysis. This urges for the development of powerful, state of the art methods and computer codes for performing such analysis on complex systems. In this report an interactive, computer aided approach is discussed, based on the well known fault tree technique. The time consuming and difficut task of manually constructing a system model (one or more fault trees) is replaced by an efficient interactive procedure in which the flexibility and the learning process inherent to the manual approach are combined with the accuracy in the modelling and the speed of the fully automatical approach. The method presented is based upon the use of a library containing component models. The possibility of setting up a standard library of models of general use and the link with a data collection system are discussed. The method has been implemented in the CAFTS-SALP software package which is described shortly in the report

  13. Computer-aided system design

    Science.gov (United States)

    Walker, Carrie K.

    1991-01-01

    A technique has been developed for combining features of a systems architecture design and assessment tool and a software development tool. This technique reduces simulation development time and expands simulation detail. The Architecture Design and Assessment System (ADAS), developed at the Research Triangle Institute, is a set of computer-assisted engineering tools for the design and analysis of computer systems. The ADAS system is based on directed graph concepts and supports the synthesis and analysis of software algorithms mapped to candidate hardware implementations. Greater simulation detail is provided by the ADAS functional simulator. With the functional simulator, programs written in either Ada or C can be used to provide a detailed description of graph nodes. A Computer-Aided Software Engineering tool developed at the Charles Stark Draper Laboratory (CSDL CASE) automatically generates Ada or C code from engineering block diagram specifications designed with an interactive graphical interface. A technique to use the tools together has been developed, which further automates the design process.

  14. Detection and function of an intramolecular disulfide bond in the pH-responsive CadC of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Dönhöfer Alexandra

    2011-04-01

    Full Text Available Abstract Background In an acidic and lysine-rich environment Escherichia coli induces expression of the cadBA operon which encodes CadA, the lysine decarboxylase, and CadB, the lysine/cadaverine antiporter. cadBA expression is dependent on CadC, a membrane-integrated transcriptional activator which belongs to the ToxR-like protein family. Activation of CadC requires two stimuli, lysine and low pH. Whereas lysine is detected by an interplay between CadC and the lysine-specific transporter LysP, pH alterations are sensed by CadC directly. Crystal structural analyses revealed a close proximity between two periplasmic cysteines, Cys208 and Cys272. Results Substitution of Cys208 and/or Cys272 by alanine resulted in CadC derivatives that were active in response to only one stimulus, either lysine or pH 5.8. Differential in vivo thiol trapping revealed a disulfide bond between these two residues at pH 7.6, but not at pH 5.8. When Cys208 and Cys272 were replaced by aspartate and lysine, respectively, virtually wild-type behavior was restored indicating that the disulfide bond could be mimicked by a salt bridge. Conclusion A disulfide bond was found in the periplasmic domain of CadC that supports an inactive state of CadC at pH 7.6. At pH 5.8 disulfide bond formation is prevented which transforms CadC into a semi-active state. These results provide new insights into the function of a pH sensor.

  15. 3D CAD ON Qinshan CANDU project

    International Nuclear Information System (INIS)

    Goland, D.

    2000-01-01

    This paper briefly describe AECL's work in applying computer-aided engineering tools to the Qinshan CANDU project. The main thrust of this paper is to introduce the major CAD software tools and their use in civil design, process design and EI and C design. Other special software tools and non-CAD tools and their applications are also briefly introduced. (author)

  16. Sharing the learning activity using intelligent CAD

    DEFF Research Database (Denmark)

    Duffy, S. M.; Duffy, Alex

    1996-01-01

    In this paper the need for Intelligent Computer Aided Design (Int.CAD) to jointly support design and learning assistance is introduced. The paper focuses on presenting and exploring the possibility of realizing ''learning'' assistance in Int.CAD by introducing a new concept called Shared Learning...

  17. Assessment of the fit of removable partial denture fabricated by computer-aided designing/computer aided manufacturing technology.

    Science.gov (United States)

    Arafa, Khalid A O

    2018-01-01

    To assess the level of evidence that supports the quality of fit for removable partial denture (RPD) fabricated by computer-aided designing/computer aided manufacturing (CAD/CAM) and rapid prototyping (RP) technology. Methods: An electronic search was performed in Google Scholar, PubMed, and Cochrane library search engines, using Boolean operators. All articles published in English and published in the period from 1950 until April 2017 were eligible to be included in this review. The total number of articles contained the search terms in any part of the article (including titles, abstracts, or article texts) were screened, which resulted in 214 articles. After exclusion of irrelevant and duplicated articles, 12 papers were included in this systematic review.  Results: All the included studies were case reports, except one study, which was a case series that recruited 10 study participants. The visual and tactile examination in the cast or clinically in the patient's mouth was the most-used method for assessment of the fit of RPDs. From all included studies, only one has assessed the internal fit between RPDs and oral tissues using silicone registration material. The vast majority of included studies found that the fit of RPDs ranged from satisfactory to excellent fit. Conclusion: Despite the lack of clinical trials that provide strong evidence, the available evidence supported the claim of good fit of RPDs fabricated by new technologies using CAD/CAM.

  18. CAD for CT colonography: toward a preparation-independent scheme

    International Nuclear Information System (INIS)

    Naeppi, J.

    2007-01-01

    Computer-aided detection (CAD) systems can be used to automatically detect and display the locations of polyps and masses in computed tomographic colonography (CTC) data for assisting radiologists' image interpretation. Rapid technical advancements over the last few years have established a fundamental CAD scheme for CTC that includes the steps of colon extraction, polyp detection, and false-positive (FP) reduction. Several CAD prototype systems have demonstrated clinically acceptable high polyp detection sensitivity with relatively few FP detections in cathartic CTC, and observer studies have demonstrated the potential benefit of such systems in improving the accuracy and consistency of radiologists' detection performance. Some CAD prototype systems have also demonstrated promising performance in reduced cathartic and non-cathartic CTC. Recent advancements suggest that CAD systems can soon be expected to provide a preparation-independent scheme that can yield consistently high detection sensitivity with moderately low FP rate not only with cathartic CTC protocols but over a wide range of cathartic, reduced cathartic, and non-cathartic CTC protocols. (orig.)

  19. CAESY - COMPUTER AIDED ENGINEERING SYSTEM

    Science.gov (United States)

    Wette, M. R.

    1994-01-01

    Many developers of software and algorithms for control system design have recognized that current tools have limits in both flexibility and efficiency. Many forces drive the development of new tools including the desire to make complex system modeling design and analysis easier and the need for quicker turnaround time in analysis and design. Other considerations include the desire to make use of advanced computer architectures to help in control system design, adopt new methodologies in control, and integrate design processes (e.g., structure, control, optics). CAESY was developed to provide a means to evaluate methods for dealing with user needs in computer-aided control system design. It is an interpreter for performing engineering calculations and incorporates features of both Ada and MATLAB. It is designed to be reasonably flexible and powerful. CAESY includes internally defined functions and procedures, as well as user defined ones. Support for matrix calculations is provided in the same manner as MATLAB. However, the development of CAESY is a research project, and while it provides some features which are not found in commercially sold tools, it does not exhibit the robustness that many commercially developed tools provide. CAESY is written in C-language for use on Sun4 series computers running SunOS 4.1.1 and later. The program is designed to optionally use the LAPACK math library. The LAPACK math routines are available through anonymous ftp from research.att.com. CAESY requires 4Mb of RAM for execution. The standard distribution medium is a .25 inch streaming magnetic tape cartridge (QIC-24) in UNIX tar format. CAESY was developed in 1993 and is a copyrighted work with all copyright vested in NASA.

  20. [Research and application of computer-aided technology in restoration of maxillary defect].

    Science.gov (United States)

    Cheng, Xiaosheng; Liao, Wenhe; Hu, Qingang; Wang, Qian; Dai, Ning

    2008-08-01

    This paper presents a new method of designing restoration model of maxillectomy defect through Computer aided technology. Firstly, 3D maxillectomy triangle mesh model is constructed from Helical CT data. Secondly, the triangle mesh model is transformed into initial computer-aided design (CAD) model of maxillectomy through reverse engineering software. Thirdly, the 3D virtual restoration model of maxillary defect is obtained after designing and adjusting the initial CAD model through CAD software according to the patient's practical condition. Therefore, the 3D virtual restoration can be fitted very well with the broken part of maxilla. The exported design data can be manufactured using rapid prototyping technology and foundry technology. Finally, the result proved that this method is effective and feasible.

  1. Computer-aided diagnosis of contrast-enhanced spectral mammography: A feasibility study.

    Science.gov (United States)

    Patel, Bhavika K; Ranjbar, Sara; Wu, Teresa; Pockaj, Barbara A; Li, Jing; Zhang, Nan; Lobbes, Mark; Zhang, Bin; Mitchell, J Ross

    2018-01-01

    To evaluate whether the use of a computer-aided diagnosis-contrast-enhanced spectral mammography (CAD-CESM) tool can further increase the diagnostic performance of CESM compared with that of experienced radiologists. This IRB-approved retrospective study analyzed 50 lesions described on CESM from August 2014 to December 2015. Histopathologic analyses, used as the criterion standard, revealed 24 benign and 26 malignant lesions. An expert breast radiologist manually outlined lesion boundaries on the different views. A set of morphologic and textural features were then extracted from the low-energy and recombined images. Machine-learning algorithms with feature selection were used along with statistical analysis to reduce, select, and combine features. Selected features were then used to construct a predictive model using a support vector machine (SVM) classification method in a leave-one-out-cross-validation approach. The classification performance was compared against the diagnostic predictions of 2 breast radiologists with access to the same CESM cases. Based on the SVM classification, CAD-CESM correctly identified 45 of 50 lesions in the cohort, resulting in an overall accuracy of 90%. The detection rate for the malignant group was 88% (3 false-negative cases) and 92% for the benign group (2 false-positive cases). Compared with the model, radiologist 1 had an overall accuracy of 78% and a detection rate of 92% (2 false-negative cases) for the malignant group and 62% (10 false-positive cases) for the benign group. Radiologist 2 had an overall accuracy of 86% and a detection rate of 100% for the malignant group and 71% (8 false-positive cases) for the benign group. The results of our feasibility study suggest that a CAD-CESM tool can provide complementary information to radiologists, mainly by reducing the number of false-positive findings. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. 3D Silicon Coincidence Avalanche Detector (3D-SiCAD) for charged particle detection

    Science.gov (United States)

    Vignetti, M. M.; Calmon, F.; Pittet, P.; Pares, G.; Cellier, R.; Quiquerez, L.; Chaves de Albuquerque, T.; Bechetoille, E.; Testa, E.; Lopez, J.-P.; Dauvergne, D.; Savoy-Navarro, A.

    2018-02-01

    Single-Photon Avalanche Diodes (SPADs) are p-n junctions operated in Geiger Mode by applying a reverse bias above the breakdown voltage. SPADs have the advantage of featuring single photon sensitivity with timing resolution in the picoseconds range. Nevertheless, their relatively high Dark Count Rate (DCR) is a major issue for charged particle detection, especially when it is much higher than the incoming particle rate. To tackle this issue, we have developed a 3D Silicon Coincidence Avalanche Detector (3D-SiCAD). This novel device implements two vertically aligned SPADs featuring on-chip electronics for the detection of coincident avalanche events occurring on both SPADs. Such a coincidence detection mode allows an efficient discrimination of events related to an incoming charged particle (producing a quasi-simultaneous activation of both SPADs) from dark counts occurring independently on each SPAD. A 3D-SiCAD detector prototype has been fabricated in CMOS technology adopting a 3D flip-chip integration technique, and the main results of its characterization are reported in this work. The particle detection efficiency and noise rejection capability for this novel device have been evaluated by means of a β- strontium-90 radioactive source. Moreover the impact of the main operating parameters (i.e. the hold-off time, the coincidence window duration, the SPAD excess bias voltage) over the particle detection efficiency has been studied. Measurements have been performed with different β- particles rates and show that a 3D-SiCAD device outperforms single SPAD detectors: the former is indeed capable to detect particle rates much lower than the individual DCR observed in a single SPAD-based detectors (i.e. 2 to 3 orders of magnitudes lower).

  3. Improving the radiologist-CAD interaction : designing for appropriate trust

    NARCIS (Netherlands)

    Jorritsma, W.; Cnossen, F.; van Ooijen, P. M. A.

    Computer-aided diagnosis (CAD) has great potential to improve radiologists' diagnostic performance. However, the reported performance of the radiologist-CAD team is lower than what might be expected based on the performance of the radiologist and the CAD system in isolation. This indicates that the

  4. Ratsnake: A Versatile Image Annotation Tool with Application to Computer-Aided Diagnosis

    Directory of Open Access Journals (Sweden)

    D. K. Iakovidis

    2014-01-01

    Full Text Available Image segmentation and annotation are key components of image-based medical computer-aided diagnosis (CAD systems. In this paper we present Ratsnake, a publicly available generic image annotation tool providing annotation efficiency, semantic awareness, versatility, and extensibility, features that can be exploited to transform it into an effective CAD system. In order to demonstrate this unique capability, we present its novel application for the evaluation and quantification of salient objects and structures of interest in kidney biopsy images. Accurate annotation identifying and quantifying such structures in microscopy images can provide an estimation of pathogenesis in obstructive nephropathy, which is a rather common disease with severe implication in children and infants. However a tool for detecting and quantifying the disease is not yet available. A machine learning-based approach, which utilizes prior domain knowledge and textural image features, is considered for the generation of an image force field customizing the presented tool for automatic evaluation of kidney biopsy images. The experimental evaluation of the proposed application of Ratsnake demonstrates its efficiency and effectiveness and promises its wide applicability across a variety of medical imaging domains.

  5. Automatic computer-aided diagnosis of retinal nerve fiber layer defects using fundus photographs in optic neuropathy.

    Science.gov (United States)

    Oh, Ji Eun; Yang, Hee Kyung; Kim, Kwang Gi; Hwang, Jeong-Min

    2015-05-01

    To evaluate the validity of an automatic computer-aided diagnosis (CAD) system for detection of retinal nerve fiber layer (RNFL) defects on fundus photographs of glaucomatous and nonglaucomatous optic neuropathy. We have proposed an automatic detection method for RNFL defects on fundus photographs in various cases of glaucomatous and nonglaucomatous optic neuropathy. In order to detect the vertical dark bands as candidate RNFL defects, the nonuniform illumination of the fundus image was corrected, the blood vessels were removed, and the images were converted to polar coordinates with the center of the optic disc. False positives (FPs) were reduced by using knowledge-based rules. The sensitivity and FP rates for all images were calculated. We tested 98 fundus photographs with 140 RNFL defects and 100 fundus photographs of healthy normal subjects. The proposed method achieved a sensitivity of 90% and a 0.67 FP rate per image and worked well with RNFL defects with variable depths and widths, with uniformly high detection rates regardless of the angular widths of the RNFL defects. The average detection accuracy was approximately 0.94. The overall diagnostic accuracy of the proposed algorithm for detecting RNFL defects among 98 patients and 100 healthy individuals was 86% sensitivity and 75% specificity. The proposed CAD system successfully detected RNFL defects in optic neuropathies. Thus, the proposed algorithm is useful for the detection of RNFL defects.

  6. Viewing CAD Drawings on the Internet

    Science.gov (United States)

    Schwendau, Mark

    2004-01-01

    Computer aided design (CAD) has been producing 3-D models for years. AutoCAD software is frequently used to create sophisticated 3-D models. These CAD files can be exported as 3DS files for import into Autodesk's 3-D Studio Viz. In this program, the user can render and modify the 3-D model before exporting it out as a WRL (world file hyperlinked)…

  7. Computing Mass Properties From AutoCAD

    Science.gov (United States)

    Jones, A.

    1990-01-01

    Mass properties of structures computed from data in drawings. AutoCAD to Mass Properties (ACTOMP) computer program developed to facilitate quick calculations of mass properties of structures containing many simple elements in such complex configurations as trusses or sheet-metal containers. Mathematically modeled in AutoCAD or compatible computer-aided design (CAD) system in minutes by use of three-dimensional elements. Written in Microsoft Quick-Basic (Version 2.0).

  8. Marginal accuracy of computer-aided design- and computer-aided manufacturing-fabricated full-arch zirconia restoration.

    Science.gov (United States)

    Juntavee, Niwut; Sirisathit, Issarawas

    2018-01-01

    This study evaluated marginal accuracy of full-arch zirconia restoration fabricated from two digital computer-aided design and computer-aided manufacturing (CAD-CAM) systems (Trios-3 and CS3500) in comparison to conventional cast metal restoration. A stainless steel model comprising two canine and two molar abutments was used as a master model for full-arch reconstruction. The canine and molar abutments were machined in a cylindrical shape with 5° taper and chamfer margin. The CAD-CAM systems based on the digital approach were used to construct the full-arch zirconia restoration. The conventional cast metal restoration was fabricated according to a conventional lost-wax technique using nickel-chromium alloys. Ten restorations were fabricated from each system. The marginal accuracy of each restoration was determined at four locations for each abutment. An analysis of variance (ANOVA) and Tukey's honest significant difference (HSD) multiple comparisons were used to determine statistically significant difference at 95% confidence interval. The mean values of marginal accuracy of restorations fabricated from conventional casting, Trios-3, and CS3500 were 48.59±4.16 μm, 53.50±5.66 μm, and 56.47±5.52 μm, respectively. ANOVA indicated significant difference in marginal fit of restorations among various systems. The marginal discrepancy of zirconia restoration fabricated from the CS3500 system demonstrated significantly larger gap than that fabricated from the 3Shape system ( p marginal gap than the conventional cast metal restoration ( p marginal fits than that from the CS3500, although, both were slightly less accurate than the conventional cast restoration. However, the marginal discrepancies of restoration produced by both CAD-CAM systems were within the clinically acceptable range and satisfactorily precise to be suggested for construction full-arch zirconia restoration.

  9. CAT -- computer aided testing for resonant inspection

    International Nuclear Information System (INIS)

    Foley, David K.

    1998-01-01

    Application of computer technology relates to inspection and quality control. The computer aided testing (CAT) can be used to analyze various NDT technologies, such as eddy current, ultrasonics, and resonant inspection

  10. Prerequisites for Computer-Aided Cognitive Rehabilitation.

    Science.gov (United States)

    Legrand, Colette

    1989-01-01

    This paper describes computer-aided cognitive rehabilitation for mentally deficient persons. It lists motor, cognitive, emotional, and educational prerequisites to such rehabilitation and states advantages and disadvantages in using the prerequisites. (JDD)

  11. Computer-aided-design-model-assisted absolute three-dimensional shape measurement.

    Science.gov (United States)

    Li, Beiwen; Bell, Tyler; Zhang, Song

    2017-08-20

    Conventional three-dimensional (3D) shape measurement methods are typically generic to all types of objects. Yet, for many measurement conditions, such a level of generality is inessential when having the preknowledge of the object geometry. This paper introduces a novel adaptive algorithm for absolute 3D shape measurement with the assistance of the object computer-aided-design (CAD) model. The proposed algorithm includes the following major steps: (1) export the 3D point cloud data from the CAD model; (2) transform the CAD model into the camera perspective; (3) obtain a wrapped phase map from three phase-shifted fringe images; and (4) retrieve absolute phase and 3D geometry assisted by the CAD model. We demonstrate that if object CAD models are available, such an algorithm is efficient in recovering absolute 3D geometries of both simple and complex objects with only three phase-shifted fringe images.

  12. Applicability of computer-aided comprehensive tool (LINDA: LINeament Detection and Analysis) and shaded digital elevation model for characterizing and interpreting morphotectonic features from lineaments

    Science.gov (United States)

    Masoud, Alaa; Koike, Katsuaki

    2017-09-01

    Detection and analysis of linear features related to surface and subsurface structures have been deemed necessary in natural resource exploration and earth surface instability assessment. Subjectivity in choosing control parameters required in conventional methods of lineament detection may cause unreliable results. To reduce this ambiguity, we developed LINDA (LINeament Detection and Analysis), an integrated tool with graphical user interface in Visual Basic. This tool automates processes of detection and analysis of linear features from grid data of topography (digital elevation model; DEM), gravity and magnetic surfaces, as well as data from remote sensing imagery. A simple interface with five display windows forms a user-friendly interactive environment. The interface facilitates grid data shading, detection and grouping of segments, lineament analyses for calculating strike and dip and estimating fault type, and interactive viewing of lineament geometry. Density maps of the center and intersection points of linear features (segments and lineaments) are also included. A systematic analysis of test DEMs and Landsat 7 ETM+ imagery datasets in the North and South Eastern Deserts of Egypt is implemented to demonstrate the capability of LINDA and correct use of its functions. Linear features from the DEM are superior to those from the imagery in terms of frequency, but both linear features agree with location and direction of V-shaped valleys and dykes and reference fault data. Through the case studies, LINDA applicability is demonstrated to highlight dominant structural trends, which can aid understanding of geodynamic frameworks in any region.

  13. Remote handling prospects. Computer aided remote handling

    International Nuclear Information System (INIS)

    Vertut, J.

    1984-01-01

    Mechanical manipulators, electrical control manipulators and computer aided manipulators were successively developed. The aim of computer aided manipulators is the realization of complex or tricky job in adverse environment but man is required for non routine work or for situation in evolution. French effort is developed in the frame of the project automation and advanced robotics and new problems have to be solved particularly at the interface man/machine [fr

  14. False-positive reduction in CAD mass detection using a competitive classification strategy

    International Nuclear Information System (INIS)

    Li Lihua; Zheng Yang; Zhang Lei; Clark, Robert A.

    2001-01-01

    High false-positive (FP) rate remains to be one of the major problems to be solved in CAD study because too many false-positively cued signals will potentially degrade the performance of detecting true-positive regions and increase the call-back rate in CAD environment. In this paper, we proposed a novel classification method for FP reduction, where the conventional 'hard' decision classifier is cascaded with a 'soft' decision classification with the objective to reduce false-positives in the cases with multiple FPs retained after the 'hard' decision classification. The 'soft' classification takes a competitive classification strategy in which only the 'best' ones are selected from the pre-classified suspicious regions as the true mass in each case. A neural network structure is designed to implement the proposed competitive classification. Comparative studies of FP reduction on a database of 79 images by a 'hard' decision classification and a combined 'hard'-'soft' classification method demonstrated the efficiency of the proposed classification strategy. For example, for the high FP sub-database which has only 31.7% of total images but accounts for 63.5% of whole FPs generated in single 'hard' classification, the FPs can be reduced for 56% (from 8.36 to 3.72 per image) by using the proposed method at the cost of 1% TP loss (from 69% to 68%) in whole database, while it can only be reduced for 27% (from 8.36 to 6.08 per image) by simply increasing the threshold of 'hard' classifier with a cost of TP loss as high as 14% (from 69% to 55%). On the average in whole database, the FP reduction by hybrid 'hard'-'soft' classification is 1.58 per image as compared to 1.11 by 'hard' classification at the TP costs described above. Because the cases with high dense tissue are of higher risk of cancer incidence and false-negative detection in mammogram screening, and usually generate more FPs in CAD detection, the method proposed in this paper will be very helpful in improving

  15. Computer-aided diagnostics of screening mammography using content-based image retrieval

    Science.gov (United States)

    Deserno, Thomas M.; Soiron, Michael; de Oliveira, Júlia E. E.; de A. Araújo, Arnaldo

    2012-03-01

    Breast cancer is one of the main causes of death among women in occidental countries. In the last years, screening mammography has been established worldwide for early detection of breast cancer, and computer-aided diagnostics (CAD) is being developed to assist physicians reading mammograms. A promising method for CAD is content-based image retrieval (CBIR). Recently, we have developed a classification scheme of suspicious tissue pattern based on the support vector machine (SVM). In this paper, we continue moving towards automatic CAD of screening mammography. The experiments are based on in total 10,509 radiographs that have been collected from different sources. From this, 3,375 images are provided with one and 430 radiographs with more than one chain code annotation of cancerous regions. In different experiments, this data is divided into 12 and 20 classes, distinguishing between four categories of tissue density, three categories of pathology and in the 20 class problem two categories of different types of lesions. Balancing the number of images in each class yields 233 and 45 images remaining in each of the 12 and 20 classes, respectively. Using a two-dimensional principal component analysis, features are extracted from small patches of 128 x 128 pixels and classified by means of a SVM. Overall, the accuracy of the raw classification was 61.6 % and 52.1 % for the 12 and the 20 class problem, respectively. The confusion matrices are assessed for detailed analysis. Furthermore, an implementation of a SVM-based CBIR system for CADx in screening mammography is presented. In conclusion, with a smarter patch extraction, the CBIR approach might reach precision rates that are helpful for the physicians. This, however, needs more comprehensive evaluation on clinical data.

  16. Computer-aided diagnosis of mammographic microcalcification clusters

    International Nuclear Information System (INIS)

    Kallergi, Maria

    2004-01-01

    Computer-aided diagnosis techniques in medical imaging are developed for the automated differentiation between benign and malignant lesions and go beyond computer-aided detection by providing cancer likelihood for a detected lesion given image and/or patient characteristics. The goal of this study was the development and evaluation of a computer-aided detection and diagnosis algorithm for mammographic calcification clusters. The emphasis was on the diagnostic component, although the algorithm included automated detection, segmentation, and classification steps based on wavelet filters and artificial neural networks. Classification features were selected primarily from descriptors of the morphology of the individual calcifications and the distribution of the cluster. Thirteen such descriptors were selected and, combined with patient's age, were given as inputs to the network. The features were ranked and evaluated for the classification of 100 high-resolution, digitized mammograms containing biopsy-proven, benign and malignant calcification clusters. The classification performance of the algorithm reached a 100% sensitivity for a specificity of 85% (receiver operating characteristic area index A z =0.98±0.01). Tests of the algorithm under various conditions showed that the selected features were robust morphological and distributional descriptors, relatively insensitive to segmentation and detection errors such as false positive signals. The algorithm could exceed the performance of a similar visual analysis system that was used as basis for development and, combined with a simple image standardization process, could be applied to images from different imaging systems and film digitizers with similar sensitivity and specificity rates

  17. Schools (Students) Exchanging CAD/CAM Files over the Internet.

    Science.gov (United States)

    Mahoney, Gary S.; Smallwood, James E.

    This document discusses how students and schools can benefit from exchanging computer-aided design/computer-aided manufacturing (CAD/CAM) files over the Internet, explains how files are exchanged, and examines the problem of selected hardware/software incompatibility. Key terms associated with information search services are defined, and several…

  18. Harmonizing interoperability - Emergent Serious Gaming in Playful Stochastic CAD Environments

    NARCIS (Netherlands)

    Kosmadoudi, Z.; Lim, T.; Ritchie, J.M.; Liu, Y.; Sung, R.; Hauge, J.B.; Garbaya, S.; Wendrich, Robert E.; Stanescu, I.A.; De Gloria, Alessandro

    2014-01-01

    Computer-Aided Design (CAD) applications often promote memorable experiences for the wrong reasons. Coupled with complex functionality and poor user experience the learning curve is often steep and overwhelming. Invoking design creativity remains limited to conveying established geometry. Gameplay

  19. CAD-CAE in Electrical Machines and Drives Teaching.

    Science.gov (United States)

    Belmans, R.; Geysen, W.

    1988-01-01

    Describes the use of computer-aided design (CAD) techniques in teaching the design of electrical motors. Approaches described include three technical viewpoints, such as electromagnetics, thermal, and mechanical aspects. Provides three diagrams, a table, and conclusions. (YP)

  20. Needs assessment for next generation computer-aided mammography reference image databases and evaluation studies.

    Science.gov (United States)

    Horsch, Alexander; Hapfelmeier, Alexander; Elter, Matthias

    2011-11-01

    Breast cancer is globally a major threat for women's health. Screening and adequate follow-up can significantly reduce the mortality from breast cancer. Human second reading of screening mammograms can increase breast cancer detection rates, whereas this has not been proven for current computer-aided detection systems as "second reader". Critical factors include the detection accuracy of the systems and the screening experience and training of the radiologist with the system. When assessing the performance of systems and system components, the choice of evaluation methods is particularly critical. Core assets herein are reference image databases and statistical methods. We have analyzed characteristics and usage of the currently largest publicly available mammography database, the Digital Database for Screening Mammography (DDSM) from the University of South Florida, in literature indexed in Medline, IEEE Xplore, SpringerLink, and SPIE, with respect to type of computer-aided diagnosis (CAD) (detection, CADe, or diagnostics, CADx), selection of database subsets, choice of evaluation method, and quality of descriptions. 59 publications presenting 106 evaluation studies met our selection criteria. In 54 studies (50.9%), the selection of test items (cases, images, regions of interest) extracted from the DDSM was not reproducible. Only 2 CADx studies, not any CADe studies, used the entire DDSM. The number of test items varies from 100 to 6000. Different statistical evaluation methods are chosen. Most common are train/test (34.9% of the studies), leave-one-out (23.6%), and N-fold cross-validation (18.9%). Database-related terminology tends to be imprecise or ambiguous, especially regarding the term "case". Overall, both the use of the DDSM as data source for evaluation of mammography CAD systems, and the application of statistical evaluation methods were found highly diverse. Results reported from different studies are therefore hardly comparable. Drawbacks of the DDSM

  1. Novel method of fabricating individual trays for maxillectomy patients by computer-aided design and rapid prototyping.

    Science.gov (United States)

    Huang, Zhi; Wang, Xin-zhi; Hou, Yue-Zhong

    2015-02-01

    Making impressions for maxillectomy patients is an essential but difficult task. This study developed a novel method to fabricate individual trays by computer-aided design (CAD) and rapid prototyping (RP) to simplify the process and enhance patient safety. Five unilateral maxillectomy patients were recruited for this study. For each patient, a computed tomography (CT) scan was taken. Based on the 3D surface reconstruction of the target area, an individual tray was manufactured by CAD/RP. With a conventional custom tray as control, two final impressions were made using the different types of tray for each patient. The trays were sectioned, and in each section the thickness of the material was measured at six evenly distributed points. Descriptive statistics and paired t-test were used to examine the difference of the impression thickness. SAS 9.3 was applied in the statistical analysis. Afterwards, all casts were then optically 3D scanned and compared digitally to evaluate the feasibility of this method. Impressions of all five maxillectomy patients were successfully made with individual trays fabricated by CAD/RP and traditional trays. The descriptive statistics of impression thickness measurement showed slightly more uneven results in the traditional trays, but no statistical significance was shown. A 3D digital comparison showed acceptable discrepancies within 1 mm in the majority of cast areas. The largest difference of 3 mm was observed in the buccal wall of the defective areas. Moderate deviations of 1 to 2 mm were detected in the buccal and labial vestibular groove areas. This study confirmed the feasibility of a novel method of fabricating individual trays by CAD/RP. Impressions made by individual trays manufactured using CAD/RP had a uniform thickness, with an acceptable level of accuracy compared to those made through conventional processes. © 2014 by the American College of Prosthodontists.

  2. Decision optimization of case-based computer-aided decision systems using genetic algorithms with application to mammography

    International Nuclear Information System (INIS)

    Mazurowski, Maciej A; Habas, Piotr A; Zurada, Jacek M; Tourassi, Georgia D

    2008-01-01

    This paper presents an optimization framework for improving case-based computer-aided decision (CB-CAD) systems. The underlying hypothesis of the study is that each example in the knowledge database of a medical decision support system has different importance in the decision making process. A new decision algorithm incorporating an importance weight for each example is proposed to account for these differences. The search for the best set of importance weights is defined as an optimization problem and a genetic algorithm is employed to solve it. The optimization process is tailored to maximize the system's performance according to clinically relevant evaluation criteria. The study was performed using a CAD system developed for the classification of regions of interests (ROIs) in mammograms as depicting masses or normal tissue. The system was constructed and evaluated using a dataset of ROIs extracted from the Digital Database for Screening Mammography (DDSM). Experimental results show that, according to receiver operator characteristic (ROC) analysis, the proposed method significantly improves the overall performance of the CAD system as well as its average specificity for high breast mass detection rates

  3. Evaluation of the fracture resistance of computer-aided design/computer-aided manufacturing monolithic crowns prepared in different cement thicknesses.

    Science.gov (United States)

    Sagsoz, N Polat; Yanıkoglu, N

    2018-04-01

    The purpose of this study was to evaluate the fracture resistance of monolithic computer-aided design/computer-aided manufacturing (CAD/CAM) crowns that are prepared with different cement thickness. For this investigation, a human maxillary premolar tooth was selected. Master model preparation was performed with a demand bur under water spray. Master die was taken to fabricate 105 epoxy resin replicas. The crowns were milled using a CEREC 4 CAD/CAM system (Software Version, 4.2.0.57192). CAD/CAM crowns were made using resin nanoceramic, feldspathic glass ceramic, lithium disilicate, and leucite-reinforced ceramics. Each group was subdivided into three groups in accordance with three different cement thicknesses (30, 90, and 150 μm). Crowns milled out. Then RelyX ™ U200 was used as a luting agent to bond the crowns to the prepared samples. After one hour cementations, the specimens were stored in water bath at 37°C for 1 week before testing. Seven unprepared and unrestored teeth were kept and tested as a control group. A universal test machine was used to assume the fracture resistance of all specimens. The compressive load (N) that caused fracture was recorded for each specimen. Fracture resistance data were statistically analyzed by one-way ANOVA and two-factor interaction modeling test (α = 0.001). There are statistically significant differences between fracture resistances of CAD/CAM monolithic crown materials (P cement thickness is not statistically significant for fracture resistance of CAD/CAM monolithic crowns (P > 0.001). CAD/CAM monolithic crown materials affected fracture resistance. Cement thickness (30, 90, and 150 μm) was not effective on fracture resistance of CAD/CAM monolithic crowns.

  4. Curved planar reformation and optimal path tracing (CROP) method for false positive reduction in computer-aided detection of pulmonary embolism in CTPA

    Science.gov (United States)

    Zhou, Chuan; Chan, Heang-Ping; Guo, Yanhui; Wei, Jun; Chughtai, Aamer; Hadjiiski, Lubomir M.; Sundaram, Baskaran; Patel, Smita; Kuriakose, Jean W.; Kazerooni, Ella A.

    2013-03-01

    The curved planar reformation (CPR) method re-samples the vascular structures along the vessel centerline to generate longitudinal cross-section views. The CPR technique has been commonly used in coronary CTA workstation to facilitate radiologists' visual assessment of coronary diseases, but has not yet been used for pulmonary vessel analysis in CTPA due to the complicated tree structures and the vast network of pulmonary vasculature. In this study, a new curved planar reformation and optimal path tracing (CROP) method was developed to facilitate feature extraction and false positive (FP) reduction and improve our PE detection system. PE candidates are first identified in the segmented pulmonary vessels at prescreening. Based on Dijkstra's algorithm, the optimal path (OP) is traced from the pulmonary trunk bifurcation point to each PE candidate. The traced vessel is then straightened and a reformatted volume is generated using CPR. Eleven new features that characterize the intensity, gradient, and topology are extracted from the PE candidate in the CPR volume and combined with the previously developed 9 features to form a new feature space for FP classification. With IRB approval, CTPA of 59 PE cases were retrospectively collected from our patient files (UM set) and 69 PE cases from the PIOPED II data set with access permission. 595 and 800 PEs were manually marked by experienced radiologists as reference standard for the UM and PIOPED set, respectively. At a test sensitivity of 80%, the average FP rate was improved from 18.9 to 11.9 FPs/case with the new method for the PIOPED set when the UM set was used for training. The FP rate was improved from 22.6 to 14.2 FPs/case for the UM set when the PIOPED set was used for training. The improvement in the free response receiver operating characteristic (FROC) curves was statistically significant (p<0.05) by JAFROC analysis, indicating that the new features extracted from the CROP method are useful for FP reduction.

  5. Training and Validating a Deep Convolutional Neural Network for Computer-Aided Detection and Classification of Abnormalities on Frontal Chest Radiographs.

    Science.gov (United States)

    Cicero, Mark; Bilbily, Alexander; Colak, Errol; Dowdell, Tim; Gray, Bruce; Perampaladas, Kuhan; Barfett, Joseph

    2017-05-01

    Convolutional neural networks (CNNs) are a subtype of artificial neural network that have shown strong performance in computer vision tasks including image classification. To date, there has been limited application of CNNs to chest radiographs, the most frequently performed medical imaging study. We hypothesize CNNs can learn to classify frontal chest radiographs according to common findings from a sufficiently large data set. Our institution's research ethics board approved a single-center retrospective review of 35,038 adult posterior-anterior chest radiographs and final reports performed between 2005 and 2015 (56% men, average age of 56, patient type: 24% inpatient, 39% outpatient, 37% emergency department) with a waiver for informed consent. The GoogLeNet CNN was trained using 3 graphics processing units to automatically classify radiographs as normal (n = 11,702) or into 1 or more of cardiomegaly (n = 9240), consolidation (n = 6788), pleural effusion (n = 7786), pulmonary edema (n = 1286), or pneumothorax (n = 1299). The network's performance was evaluated using receiver operating curve analysis on a test set of 2443 radiographs with the criterion standard being board-certified radiologist interpretation. Using 256 × 256-pixel images as input, the network achieved an overall sensitivity and specificity of 91% with an area under the curve of 0.964 for classifying a study as normal (n = 1203). For the abnormal categories, the sensitivity, specificity, and area under the curve, respectively, were 91%, 91%, and 0.962 for pleural effusion (n = 782), 82%, 82%, and 0.868 for pulmonary edema (n = 356), 74%, 75%, and 0.850 for consolidation (n = 214), 81%, 80%, and 0.875 for cardiomegaly (n = 482), and 78%, 78%, and 0.861 for pneumothorax (n = 167). Current deep CNN architectures can be trained with modest-sized medical data sets to achieve clinically useful performance at detecting and excluding common pathology on chest radiographs.

  6. Computer aided analysis, simulation and optimisation of thermal sterilisation processes.

    Science.gov (United States)

    Narayanan, C M; Banerjee, Arindam

    2013-04-01

    Although thermal sterilisation is a widely employed industrial process, little work is reported in the available literature including patents on the mathematical analysis and simulation of these processes. In the present work, software packages have been developed for computer aided optimum design of thermal sterilisation processes. Systems involving steam sparging, jacketed heating/cooling, helical coils submerged in agitated vessels and systems that employ external heat exchangers (double pipe, shell and tube and plate exchangers) have been considered. Both batch and continuous operations have been analysed and simulated. The dependence of del factor on system / operating parameters such as mass or volume of substrate to be sterilised per batch, speed of agitation, helix diameter, substrate to steam ratio, rate of substrate circulation through heat exchanger and that through holding tube have been analysed separately for each mode of sterilisation. Axial dispersion in the holding tube has also been adequately accounted for through an appropriately defined axial dispersion coefficient. The effect of exchanger characteristics/specifications on the system performance has also been analysed. The multiparameter computer aided design (CAD) software packages prepared are thus highly versatile in nature and they permit to make the most optimum choice of operating variables for the processes selected. The computed results have been compared with extensive data collected from a number of industries (distilleries, food processing and pharmaceutical industries) and pilot plants and satisfactory agreement has been observed between the two, thereby ascertaining the accuracy of the CAD softwares developed. No simplifying assumptions have been made during the analysis and the design of associated heating / cooling equipment has been performed utilising the most updated design correlations and computer softwares.

  7. Three-class classification in computer-aided diagnosis of breast cancer by support vector machine

    Science.gov (United States)

    Sun, Xuejun; Qian, Wei; Song, Dansheng

    2004-05-01

    Design of classifier in computer-aided diagnosis (CAD) scheme of breast cancer plays important role to its overall performance in sensitivity and specificity. Classification of a detected object as malignant lesion, benign lesion, or normal tissue on mammogram is a typical three-class pattern recognition problem. This paper presents a three-class classification approach by using two-stage classifier combined with support vector machine (SVM) learning algorithm for classification of breast cancer on mammograms. The first classification stage is used to detect abnormal areas and normal breast tissues, and the second stage is for classification of malignant or benign in detected abnormal objects. A series of spatial, morphology and texture features have been extracted on detected objects areas. By using genetic algorithm (GA), different feature groups for different stage classification have been investigated. Computerized free-response receiver operating characteristic (FROC) and receiver operating characteristic (ROC) analyses have been employed in different classification stages. Results have shown that obvious performance improvement in both sensitivity and specificity was observed through proposed classification approach compared with conventional two-class classification approaches, indicating its effectiveness in classification of breast cancer on mammograms.

  8. Computer-aided method for identification of major flavone/flavonol glycosides by high-performance liquid chromatography-diode array detection-tandem mass spectrometry (HPLC-DAD-MS/MS).

    Science.gov (United States)

    Wang, Zhengfang; Lin, Longze; Harnly, James M; Harrington, Peter de B; Chen, Pei

    2014-11-01

    A new computational tool is proposed here for tentatively identifying major (UV quantifiable) flavone/flavonol glycoside peaks of high performance liquid chromatogram (HPLC)-diode array detection (DAD)-tandem mass spectrometry (MS/MS) profiles based on a MATLAB-based script implementing an in-house algorithm. The HPLC-DAD-MS/MS profiles of red onion, Chinese lettuce, carrot leaf, and celery seed extracts were analyzed by the proposed computer-aided screening method for identifying possible flavone/flavonol glycoside peaks from the HPLC-UV and MS total ion current (TIC) chromatograms. The number of identified flavone/flavonol glycoside peaks of the HPLC-UV chromatograms is four, four, six, and nine for red onion, Chinese lettuce, carrot leaf, and celery seed, respectively. These results have been validated by human(s) experts. For the batch processing of nine HPLC-DAD-MS/MS profiles of celery seed extract, the entire script execution time was within 15 s while manual calculation of only one HPLC-DAD-MS/MS profile by a flavonoid expert could take hours. Therefore, this MATLAB-based screening method is able to facilitate the HPLC-DAD-MS/MS analysis of flavone/flavonol glycosides in plants to a large extent.

  9. Trend and application of CAD/CAM system

    International Nuclear Information System (INIS)

    Kang, Man Ok

    1984-09-01

    This report is about trend and application of CAD/CAM system, giving descriptions of computer aided design which helps construction, engineering and drafting tasks. It also tells of computer aided manufacturing related general design of manufactures, which includes process design, production management, decision of work technology, processing. The need and application of CAD/CAM system is increasing more and more for industry each area.

  10. Incorporation of CAD/CAM Restoration Into Navy Dentistry

    Science.gov (United States)

    2017-09-26

    CAD/CAM Computer-aided design /Computer-assisted manufacturing CDT Common Dental Terminology DENCAS Dental Common Access System DTF Dental...to reduce avoidable dental emergencies for deployed sailors and marines. Dental Computer-aided design /Computer-assisted manufacturing (CAD/CAM...this time by allowing for rapid scanning, designing , development, and production of dental restorations. Using this technology gives dentists the

  11. Recent advances in the reconstruction of cranio-maxillofacial defects using computer-aided design/computer-aided manufacturing.

    Science.gov (United States)

    Oh, Ji-Hyeon

    2018-12-01

    With the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology, it has been possible to reconstruct the cranio-maxillofacial defect with more accurate preoperative planning, precise patient-specific implants (PSIs), and shorter operation times. The manufacturing processes include subtractive manufacturing and additive manufacturing and should be selected in consideration of the material type, available technology, post-processing, accuracy, lead time, properties, and surface quality. Materials such as titanium, polyethylene, polyetheretherketone (PEEK), hydroxyapatite (HA), poly-DL-lactic acid (PDLLA), polylactide-co-glycolide acid (PLGA), and calcium phosphate are used. Design methods for the reconstruction of cranio-maxillofacial defects include the use of a pre-operative model printed with pre-operative data, printing a cutting guide or template after virtual surgery, a model after virtual surgery printed with reconstructed data using a mirror image, and manufacturing PSIs by directly obtaining PSI data after reconstruction using a mirror image. By selecting the appropriate design method, manufacturing process, and implant material according to the case, it is possible to obtain a more accurate surgical procedure, reduced operation time, the prevention of various complications that can occur using the traditional method, and predictive results compared to the traditional method.

  12. Computer-aided diagnosis of prostate cancer using multi-parametric MRI: comparison between PUN and Tofts models

    Science.gov (United States)

    Mazzetti, S.; Giannini, V.; Russo, F.; Regge, D.

    2018-05-01

    Computer-aided diagnosis (CAD) systems are increasingly being used in clinical settings to report multi-parametric magnetic resonance imaging (mp-MRI) of the prostate. Usually, CAD systems automatically highlight cancer-suspicious regions to the radiologist, reducing reader variability and interpretation errors. Nevertheless, implementing this software requires the selection of which mp-MRI parameters can best discriminate between malignant and non-malignant regions. To exploit functional information, some parameters are derived from dynamic contrast-enhanced (DCE) acquisitions. In particular, much CAD software employs pharmacokinetic features, such as K trans and k ep, derived from the Tofts model, to estimate a likelihood map of malignancy. However, non-pharmacokinetic models can be also used to describe DCE-MRI curves, without any requirement for prior knowledge or measurement of the arterial input function, which could potentially lead to large errors in parameter estimation. In this work, we implemented an empirical function derived from the phenomenological universalities (PUN) class to fit DCE-MRI. The parameters of the PUN model are used in combination with T2-weighted and diffusion-weighted acquisitions to feed a support vector machine classifier to produce a voxel-wise malignancy likelihood map of the prostate. The results were all compared to those for a CAD system based on Tofts pharmacokinetic features to describe DCE-MRI curves, using different quality aspects of image segmentation, while also evaluating the number and size of false positive (FP) candidate regions. This study included 61 patients with 70 biopsy-proven prostate cancers (PCa). The metrics used to evaluate segmentation quality between the two CAD systems were not statistically different, although the PUN-based CAD reported a lower number of FP, with reduced size compared to the Tofts-based CAD. In conclusion, the CAD software based on PUN parameters is a feasible means with which to

  13. Computer-aided diagnosis in chest radiology.

    Science.gov (United States)

    MacMahon, H; Doi, K; Chan, H P; Giger, M L; Katsuragawa, S; Nakamori, N

    1990-01-01

    Digital radiography offers several important advantages over conventional systems, including abilities for image manipulation, transmission, and storage. In the long term, however, the unique ability to apply artificial intelligence techniques for automated detection and quantitation of disease may have an even greater impact on radiologic practice. Although CAD is still in its infancy, the results of several recent studies clearly indicate a major potential for the future. The concept of using computers to analyze medical images is not new, but recent advances in computer technology together with progress in implementing practical digital radiography systems have stimulated research efforts in this exciting field. Several facets of CAD are presently being developed at the University of Chicago and elsewhere for application in chest radiology as well as in mammography and vascular imaging. To date, investigators have focused on a limited number of subjects that have been, by their nature, particularly suitable for computer analysis. There is no aspect of radiologic diagnosis that could not potentially benefit from this approach, however. The ultimate goal of these endeavors is to provide a system for comprehensive automated image analysis, the results of which could be accepted or modified at the discretion of the radiologist.

  14. Computer Aided Measurement Laser (CAML): technique to quantify post-mastectomy lymphoedema

    International Nuclear Information System (INIS)

    Trombetta, Chiara; Abundo, Paolo; Felici, Antonella; Ljoka, Concetta; Foti, Calogero; Cori, Sandro Di; Rosato, Nicola

    2012-01-01

    Lymphoedema can be a side effect of cancer treatment. Eventhough several methods for assessing lymphoedema are used in clinical practice, an objective quantification of lymphoedema has been problematic. The aim of the study was to determine the objectivity, reliability and repeatability of the computer aided measurement laser (CAML) technique. CAML technique is based on computer aided design (CAD) methods and requires an infrared laser scanner. Measurements are scanned and the information describing size and shape of the limb allows to design the model by using the CAD software. The objectivity and repeatability was established in the beginning using a phantom. Consequently a group of subjects presenting post-breast cancer lymphoedema was evaluated using as a control the contralateral limb. Results confirmed that in clinical settings CAML technique is easy to perform, rapid and provides meaningful data for assessing lymphoedema. Future research will include a comparison of upper limb CAML technique between healthy subjects and patients with known lymphoedema.

  15. Computer Aided Solvent Selection and Design Framework

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Conte, Elisa; Abildskov, Jens

    and computer-aided tools and methods for property prediction and computer-aided molecular design (CAMD) principles. This framework is applicable for solvent selection and design in product design as well as process design. The first module of the framework is dedicated to the solvent selection and design...... in terms of: physical and chemical properties (solvent-pure properties); Environment, Health and Safety (EHS) characteristic (solvent-EHS properties); operational properties (solvent–solute properties). 3. Performing the search. The search step consists of two stages. The first is a generation and property...... identification of solvent candidates using special software ProCAMD and ProPred, which are the implementations of computer-aided molecular techniques. The second consists of assigning the RS-indices following the reaction–solvent and then consulting the known solvent database and identifying the set of solvents...

  16. Computer Aided Drug Design: Success and Limitations.

    Science.gov (United States)

    Baig, Mohammad Hassan; Ahmad, Khurshid; Roy, Sudeep; Ashraf, Jalaluddin Mohammad; Adil, Mohd; Siddiqui, Mohammad Haris; Khan, Saif; Kamal, Mohammad Amjad; Provazník, Ivo; Choi, Inho

    2016-01-01

    Over the last few decades, computer-aided drug design has emerged as a powerful technique playing a crucial role in the development of new drug molecules. Structure-based drug design and ligand-based drug design are two methods commonly used in computer-aided drug design. In this article, we discuss the theory behind both methods, as well as their successful applications and limitations. To accomplish this, we reviewed structure based and ligand based virtual screening processes. Molecular dynamics simulation, which has become one of the most influential tool for prediction of the conformation of small molecules and changes in their conformation within the biological target, has also been taken into account. Finally, we discuss the principles and concepts of molecular docking, pharmacophores and other methods used in computer-aided drug design.

  17. CAD in breast imaging. Application in mammography and MR mammography

    International Nuclear Information System (INIS)

    Obenauer, S.; Hermann, K.P.

    2012-01-01

    Computer aided diagnosis systems (CAD-systems) are evaluated in different parts of diagnostic imaging. In breast imaging double reading which is time- and cost spending is necessary. Therefore a lot of studies evaluated the use of CAD-systems in mammography. However the rate of false-positives is too high to implement CAD-systems as double reader in routine work. In the future, improvements in this technique could perhaps change the performance of CAD-systems. (orig.)

  18. Role of radiologists in CAD life-cycle

    International Nuclear Information System (INIS)

    Pietka, Ewa; Kawa, Jacek; Spinczyk, Dominik; Badura, Pawel; Wieclawek, Wojciech; Czajkowska, Joanna; Rudzki, Marcin

    2011-01-01

    A modern CAD (computer-aided diagnosis) system development involves a multidisciplinary team whose members are experts in medical and technical fields. This study indicates the activities of medical experts at various stages of the CAD design, testing, and implementation. Those stages include a medical analysis of the diagnostic problem, data collection, image analysis, evaluation, and clinical verification. At each stage the physicians knowledge and experience are indispensable. The final implementation involves integration with the existing Picture Archiving and Communication System. The term CAD life-cycle describes an overall process of the design, testing, and implementation of a system that in its final form assists the radiologists in their daily clinical routine. Four CAD systems (applied to the bone age assessment, Multiple Sclerosis detection, lung nodule detection, and pneumothorax measurement) developed in our laboratory are given as examples of how consecutive stages are developed by the multidisciplinary team. Specific advantages of the CAD implementation that include the daily clinical routine as well as research and education activities are discussed.

  19. Role of radiologists in CAD life-cycle

    Energy Technology Data Exchange (ETDEWEB)

    Pietka, Ewa, E-mail: ewa.pietka@polsl.pl [Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, ul. Akademicka 16, 44-100 Gliwice (Poland); Kawa, Jacek, E-mail: jacek.kawa@polsl.pl [Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, ul. Akademicka 16, 44-100 Gliwice (Poland); Spinczyk, Dominik, E-mail: dominik.spinczyk@polsl.pl [Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, ul. Akademicka 16, 44-100 Gliwice (Poland); Badura, Pawel, E-mail: pawel.badura@polsl.pl [Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, ul. Akademicka 16, 44-100 Gliwice (Poland); Wieclawek, Wojciech, E-mail: wojciech.wieclawek@polsl.pl [Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, ul. Akademicka 16, 44-100 Gliwice (Poland); Czajkowska, Joanna, E-mail: joanna.czajkowska@polsl.pl [Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, ul. Akademicka 16, 44-100 Gliwice (Poland); Rudzki, Marcin, E-mail: marcin.rudzki@polsl.pl [Silesian University of Technology, Faculty of Automatic Control, Electronics and Computer Science, ul. Akademicka 16, 44-100 Gliwice (Poland)

    2011-05-15

    A modern CAD (computer-aided diagnosis) system development involves a multidisciplinary team whose members are experts in medical and technical fields. This study indicates the activities of medical experts at various stages of the CAD design, testing, and implementation. Those stages include a medical analysis of the diagnostic problem, data collection, image analysis, evaluation, and clinical verification. At each stage the physicians knowledge and experience are indispensable. The final implementation involves integration with the existing Picture Archiving and Communication System. The term CAD life-cycle describes an overall process of the design, testing, and implementation of a system that in its final form assists the radiologists in their daily clinical routine. Four CAD systems (applied to the bone age assessment, Multiple Sclerosis detection, lung nodule detection, and pneumothorax measurement) developed in our laboratory are given as examples of how consecutive stages are developed by the multidisciplinary team. Specific advantages of the CAD implementation that include the daily clinical routine as well as research and education activities are discussed.

  20. A Novel Computer-Aided Design/Computer-Assisted Manufacture Method for One-Piece Removable Partial Denture and Evaluation of Fit.

    Science.gov (United States)

    Ye, Hongqiang; Li, Xinxin; Wang, Guanbo; Kang, Jing; Liu, Yushu; Sun, Yuchun; Zhou, Yongsheng

    2018-02-15

    To investigate a computer-aided design/computer-aided manufacturing (CAD/CAM) process for producing one-piece removable partial dentures (RPDs) and to evaluate their fits in vitro. A total of 15 one-piece RPDs were designed using dental CAD and reverse engineering software and then fabricated with polyetheretherketone (PEEK) using CAM. The gaps between RPDs and casts were measured and compared with traditional cast framework RPDs. Gaps were lower for one-piece PEEK RPDs compared to traditional RPDs. One-piece RPDs can be manufactured by CAD/CAM, and their fits were better than those of traditional RPDs.

  1. Study on computer-aided diagnosis of hepatic MR imaging and mammography

    International Nuclear Information System (INIS)

    Zhang Xuejun

    2005-01-01

    It is well known that the liver is an organ easily attacked by diseases. The purpose of this study is to develop a computer-aided diagnosis (CAD) scheme for helping radiologists to differentiate hepatic diseases more efficiently. Our software named LIVERANN integrated the magnetic resonance (MR) imaging findings with different pulse sequences to classify the five categories of hepatic diseases by using the artificial neural network (ANN) method. The intensity and homogeneity within the region of interest (ROI) delineated by a radiologist were automatically calculated to obtain numerical data by the program for input signals to the ANN. Outputs were the five pathological categories of hepatic diseases (hepatic cyst, hepatocellular carcinoma, dysplasia in cirrhosis, cavernous hemangioma, and metastasis). The experiment demonstrated a testing accuracy of 93% from 80 patients. In order to differentiate the cirrhosis from normal liver, the volume ratio of left to whole (LTW) was proposed to quantify the degree of cirrhosis by three-dimensional (3D) volume analysis. The liver region was firstly extracted from computed tomography (CT) or MR slices based on edge detection algorithms, and then separated into left lobe and right lobe by the hepatic umbilical fissure. The volume ratio of these two parts showed that the LTW ratio in the liver was significantly improved in the differentiation performance, with (25.6%±4.3%) in cirrhosis versus the normal liver (16.4%±5.4%). In addition, the application of the ANN method for detecting clustered microcalcifications in masses on mammograms was described here as well. A new structural ANN, so-called a shift-invariant artificial neural network (SIANN), was integrated with our triple-ring filter (TRF) method in our CAD system. As the result, the sensitivity of detecting clusters was improved from 90% by our previous TRF method to 95% by using both SIANN and TRF

  2. [A computer aided design approach of all-ceramics abutment for maxilla central incisor].

    Science.gov (United States)

    Sun, Yu-chun; Zhao, Yi-jiao; Wang, Yong; Han, Jing-yun; Lin, Ye; Lü, Pei-jun

    2010-10-01

    To establish the computer aided design (CAD) software platform of individualized abutment for the maxilla central incisor. Three-dimentional data of the incisor was collected by scanning and geometric transformation. Data mainly included the occlusal part of the healing abutment, the location carinae of the bedpiece, the occlusal 1/3 part of the artificial gingiva's inner surface, and so on. The all-ceramic crown designed in advanced was "virtual cutback" to get the original data of the abutment's supragingival part. The abutment's in-gum part was designed to simulate the individual natural tooth root. The functions such as "data offset", "bi-rail sweep surface" and "loft surface" were used in the process of CAD. The CAD route of the individualized all-ceramic abutment was set up. The functions and application methods were decided and the complete CAD process was realized. The software platform was basically set up according to the requests of the dental clinic.

  3. Computer-aided diagnosis system for bone scintigrams from Japanese patients: importance of training database

    DEFF Research Database (Denmark)

    Horikoshi, Hiroyuki; Kikuchi, Akihiro; Onoguchi, Masahisa

    2012-01-01

    higher performance than the corresponding CAD software trained with a European database for the analysis of bone scans from Japanese patients. These results could at least partly be caused by the physical differences between Japanese and European patients resulting in less influence of attenuation......Computer-aided diagnosis (CAD) software for bone scintigrams have recently been introduced as a clinical quality assurance tool. The purpose of this study was to compare the diagnostic accuracy of two CAD systems, one based on a European and one on a Japanese training database, in a group of bone...... scans from Japanese patients.The two CAD software are trained to interpret bone scans using training databases consisting of bone scans with the desired interpretation, metastatic disease or not. One software was trained using 795 bone scans from European patients and the other with 904 bone scans from...

  4. The effects of computer-aided design software on engineering students' spatial visualisation skills

    Science.gov (United States)

    Kösa, Temel; Karakuş, Fatih

    2018-03-01

    The purpose of this study was to determine the influence of computer-aided design (CAD) software-based instruction on the spatial visualisation skills of freshman engineering students in a computer-aided engineering drawing course. A quasi-experimental design was applied, using the Purdue Spatial Visualization Test-Visualization of Rotations (PSVT:R) for both the pre- and the post-test. The participants were 116 freshman students in the first year of their undergraduate programme in the Department of Mechanical Engineering at a university in Turkey. A total of 72 students comprised the experimental group; they were instructed with CAD-based activities in an engineering drawing course. The control group consisted of 44 students who did not attend this course. The results of the study showed that a CAD-based engineering drawing course had a positive effect on developing engineering students' spatial visualisation skills. Additionally, the results of the study showed that spatial visualisation skills can be a predictor for success in a computer-aided engineering drawing course.

  5. The Effects of Cooperative and Individualistic Learning Structures on Achievement in a College-Level Computer-Aided Drafting Course

    Science.gov (United States)

    Swab, A. Geoffrey

    2012-01-01

    This study of cooperative learning in post-secondary engineering education investigated achievement of engineering students enrolled in two intact sections of a computer-aided drafting (CAD) course. Quasi-experimental and qualitative methods were employed in comparing student achievement resulting from out-of-class cooperative and individualistic…

  6. Computer Aided Design of the Link-Fork Head-Piston Assembly of the Kaplan Turbine with Solidworks

    Directory of Open Access Journals (Sweden)

    Camelia Jianu

    2010-10-01

    Full Text Available The paper presents the steps for 3D computer aided design (CAD of the link-fork head-piston assembly of the Kaplan turbine made in SolidWorks.The present paper is a tutorial for a Kaplan turbine assembly 3D geometry, which is dedicated to the Assembly design and Drawing Geometry and Drawing Annotation.

  7. Geometric and computer-aided spline hob modeling

    Science.gov (United States)

    Brailov, I. G.; Myasoedova, T. M.; Panchuk, K. L.; Krysova, I. V.; Rogoza, YU A.

    2018-03-01

    The paper considers acquiring the spline hob geometric model. The objective of the research is the development of a mathematical model of spline hob for spline shaft machining. The structure of the spline hob is described taking into consideration the motion in parameters of the machine tool system of cutting edge positioning and orientation. Computer-aided study is performed with the use of CAD and on the basis of 3D modeling methods. Vector representation of cutting edge geometry is accepted as the principal method of spline hob mathematical model development. The paper defines the correlations described by parametric vector functions representing helical cutting edges designed for spline shaft machining with consideration for helical movement in two dimensions. An application for acquiring the 3D model of spline hob is developed on the basis of AutoLISP for AutoCAD environment. The application presents the opportunity for the use of the acquired model for milling process imitation. An example of evaluation, analytical representation and computer modeling of the proposed geometrical model is reviewed. In the mentioned example, a calculation of key spline hob parameters assuring the capability of hobbing a spline shaft of standard design is performed. The polygonal and solid spline hob 3D models are acquired by the use of imitational computer modeling.

  8. Computer Aided Continuous Time Stochastic Process Modelling

    DEFF Research Database (Denmark)

    Kristensen, N.R.; Madsen, Henrik; Jørgensen, Sten Bay

    2001-01-01

    A grey-box approach to process modelling that combines deterministic and stochastic modelling is advocated for identification of models for model-based control of batch and semi-batch processes. A computer-aided tool designed for supporting decision-making within the corresponding modelling cycle...

  9. Computer aided architectural design : futures 2001

    NARCIS (Netherlands)

    Vries, de B.; Leeuwen, van J.P.; Achten, H.H.

    2001-01-01

    CAAD Futures is a bi-annual conference that aims to promote the advancement of computer-aided architectural design in the service of those concerned with the quality of the built environment. The conferences are organized under the auspices of the CAAD Futures Foundation, which has its secretariat

  10. Computer-Aided Modelling Methods and Tools

    DEFF Research Database (Denmark)

    Cameron, Ian; Gani, Rafiqul

    2011-01-01

    The development of models for a range of applications requires methods and tools. In many cases a reference model is required that allows the generation of application specific models that are fit for purpose. There are a range of computer aided modelling tools available that help to define the m...

  11. Computer-Aided Corrosion Program Management

    Science.gov (United States)

    MacDowell, Louis

    2010-01-01

    This viewgraph presentation reviews Computer-Aided Corrosion Program Management at John F. Kennedy Space Center. The contents include: 1) Corrosion at the Kennedy Space Center (KSC); 2) Requirements and Objectives; 3) Program Description, Background and History; 4) Approach and Implementation; 5) Challenges; 6) Lessons Learned; 7) Successes and Benefits; and 8) Summary and Conclusions.

  12. New Paradigms for Computer Aids to Invention.

    Science.gov (United States)

    Langston, M. Diane

    Many people are interested in computer aids to rhetorical invention and want to know how to evaluate an invention aid, what the criteria are for a good one, and how to assess the trade-offs involved in buying one product or another. The frame of reference for this evaluation is an "old paradigm," which treats the computer as if it were…

  13. [Computer-aided Prognosis for Breast Cancer Based on Hematoxylin & Eosin Histopathology Image].

    Science.gov (United States)

    Chen, Jiamei; Qu, Aiping; Liu, Wenlou; Wang, Linwei; Yuan, Jingping; Liu, Juan; Li, Yan

    2016-06-01

    Quantitatively analyzing hematoxylin &eosin(H&E)histopathology images is an emerging field attracting increasing attentions in recent years.This paper reviews the application of computer-aided image analysis in breast cancer prognosis.The traditional prognosis based on H&E histopathology image for breast cancer is firstly sketched,followed by a detailed description of the workflow of computer-aided prognosis including image acquisition,image preprocessing,regions of interest detection and object segmentation,feature extraction,and computer-aided prognosis.In the end,major technical challenges and future directions in this field are summarized.

  14. Development of a computer aided diagnosis model for prostate cancer classification on multi-parametric MRI

    Science.gov (United States)

    Alfano, R.; Soetemans, D.; Bauman, G. S.; Gibson, E.; Gaed, M.; Moussa, M.; Gomez, J. A.; Chin, J. L.; Pautler, S.; Ward, A. D.

    2018-02-01

    Multi-parametric MRI (mp-MRI) is becoming a standard in contemporary prostate cancer screening and diagnosis, and has shown to aid physicians in cancer detection. It offers many advantages over traditional systematic biopsy, which has shown to have very high clinical false-negative rates of up to 23% at all stages of the disease. However beneficial, mp-MRI is relatively complex to interpret and suffers from inter-observer variability in lesion localization and grading. Computer-aided diagnosis (CAD) systems have been developed as a solution as they have the power to perform deterministic quantitative image analysis. We measured the accuracy of such a system validated using accurately co-registered whole-mount digitized histology. We trained a logistic linear classifier (LOGLC), support vector machine (SVC), k-nearest neighbour (KNN) and random forest classifier (RFC) in a four part ROI based experiment against: 1) cancer vs. non-cancer, 2) high-grade (Gleason score ≥4+3) vs. low-grade cancer (Gleason score work will form the basis for a tool that enhances the radiologist's ability to detect malignancies, potentially improving biopsy guidance, treatment selection, and focal therapy for prostate cancer patients, maximizing the potential for cure and increasing quality of life.

  15. Introduction of effect and consideration of the introduction of CAD/CAM system

    International Nuclear Information System (INIS)

    Kang, Man Ok

    1984-12-01

    This reports introduction of effect and consideration of the introduction of computer-aided design and computer aided manufacturing system. It includes outline of CAD/CAM system like definition, classification, system kinds, and development process of CAD/CAM system, technology, market trend development prospect, and value on introduction of this system, and current application of CAD/CAM system in major application area, development countries and Korea.

  16. Computer-assisted detection (CAD) methodology for early detection of response to pharmaceutical therapy in tuberculosis patients

    Science.gov (United States)

    Lieberman, Robert; Kwong, Heston; Liu, Brent; Huang, H. K.

    2009-02-01

    The chest x-ray radiological features of tuberculosis patients are well documented, and the radiological features that change in response to successful pharmaceutical therapy can be followed with longitudinal studies over time. The patients can also be classified as either responsive or resistant to pharmaceutical therapy based on clinical improvement. We have retrospectively collected time series chest x-ray images of 200 patients diagnosed with tuberculosis receiving the standard pharmaceutical treatment. Computer algorithms can be created to utilize image texture features to assess the temporal changes in the chest x-rays of the tuberculosis patients. This methodology provides a framework for a computer-assisted detection (CAD) system that may provide physicians with the ability to detect poor treatment response earlier in pharmaceutical therapy. Early detection allows physicians to respond with more timely treatment alternatives and improved outcomes. Such a system has the potential to increase treatment efficacy for millions of patients each year.

  17. Marginal accuracy of computer-aided design- and computer-aided manufacturing-fabricated full-arch zirconia restoration

    Directory of Open Access Journals (Sweden)

    Juntavee N

    2018-02-01

    Full Text Available Niwut Juntavee,1 Issarawas Sirisathit2 1Department of Prosthodontics, 2Division of Biomaterials and Prosthodontics Research, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand Objective: This study evaluated marginal accuracy of full-arch zirconia restoration fabricated from two digital computer-aided design and computer-aided manufacturing (CAD-CAM systems (Trios-3 and CS3500 in comparison to conventional cast metal restoration. Materials and methods: A stainless steel model comprising two canine and two molar abutments was used as a master model for full-arch reconstruction. The canine and molar abutments were machined in a cylindrical shape with 5° taper and chamfer margin. The CAD-CAM systems based on the digital approach were used to construct the full-arch zirconia restoration. The conventional cast metal restoration was fabricated according to a conventional lost-wax technique using nickel–chromium alloys. Ten restorations were fabricated from each system. The marginal accuracy of each restoration was determined at four locations for each abutment. An analysis of variance (ANOVA and Tukey’s honest significant difference (HSD multiple comparisons were used to determine statistically significant difference at 95% confidence interval. Results: The mean values of marginal accuracy of restorations fabricated from conventional casting, Trios-3, and CS3500 were 48.59±4.16 μm, 53.50±5.66 μm, and 56.47±5.52 μm, respectively. ANOVA indicated significant difference in marginal fit of restorations among various systems. The marginal discrepancy of zirconia restoration fabricated from the CS3500 system demonstrated significantly larger gap than that fabricated from the 3Shape system (p<0.05. Tukey’s HSD multiple comparisons indicated that the zirconia restoration fabricated from either CS3500 or Trios-3 demonstrated a significantly larger marginal gap than the conventional cast metal restoration (p<0.05. Conclusion: Full

  18. Custom-Made Computer-Aided-Design/Computer-Aided-Manufacturing Biphasic Calcium-Phosphate Scaffold for Augmentation of an Atrophic Mandibular Anterior Ridge

    Directory of Open Access Journals (Sweden)

    Francesco Guido Mangano

    2015-01-01

    Full Text Available This report documents the clinical, radiographic, and histologic outcome of a custom-made computer-aided-design/computer-aided-manufactured (CAD/CAM scaffold used for the alveolar ridge augmentation of a severely atrophic anterior mandible. Computed tomographic (CT images of an atrophic anterior mandible were acquired and modified into a 3-dimensional (3D reconstruction model; this was transferred to a CAD program, where a custom-made scaffold was designed. CAM software generated a set of tool-paths for the manufacture of the scaffold on a computer-numerical-control milling machine into the exact shape of the 3D design. A custom-made scaffold was milled from a synthetic micromacroporous biphasic calcium phosphate (BCP block. The scaffold closely matched the shape of the defect: this helped to reduce the time for the surgery and contributed to good healing. One year later, newly formed and well-integrated bone was clinically available, and two implants (AnyRidge, MegaGen, Gyeongbuk, South Korea were placed. The histologic samples retrieved from the implant sites revealed compact mature bone undergoing remodelling, marrow spaces, and newly formed trabecular bone surrounded by residual BCP particles. This study demonstrates that custom-made scaffolds can be fabricated by combining CT scans and CAD/CAM techniques. Further studies on a larger sample of patients are needed to confirm these results.

  19. Development and evaluation of a computer-aided diagnostic scheme for lung nodule detection in chest radiographs by means of two-stage nodule enhancement with support vector classification

    International Nuclear Information System (INIS)

    Chen Sheng; Suzuki, Kenji; MacMahon, Heber

    2011-01-01

    Purpose: To develop a computer-aided detection (CADe) scheme for nodules in chest radiographs (CXRs) with a high sensitivity and a low false-positive (FP) rate. Methods: The authors developed a CADe scheme consisting of five major steps, which were developed for improving the overall performance of CADe schemes. First, to segment the lung fields accurately, the authors developed a multisegment active shape model. Then, a two-stage nodule-enhancement technique was developed for improving the conspicuity of nodules. Initial nodule candidates were detected and segmented by using the clustering watershed algorithm. Thirty-one shape-, gray-level-, surface-, and gradient-based features were extracted from each segmented candidate for determining the feature space, including one of the new features based on the Canny edge detector to eliminate a major FP source caused by rib crossings. Finally, a nonlinear support vector machine (SVM) with a Gaussian kernel was employed for classification of the nodule candidates. Results: To evaluate and compare the scheme to other published CADe schemes, the authors used a publicly available database containing 140 nodules in 140 CXRs and 93 normal CXRs. The CADe scheme based on the SVM classifier achieved sensitivities of 78.6% (110/140) and 71.4% (100/140) with averages of 5.0 (1165/233) FPs/image and 2.0 (466/233) FPs/image, respectively, in a leave-one-out cross-validation test, whereas the CADe scheme based on a linear discriminant analysis classifier had a sensitivity of 60.7% (85/140) at an FP rate of 5.0 FPs/image. For nodules classified as ''very subtle'' and ''extremely subtle,'' a sensitivity of 57.1% (24/42) was achieved at an FP rate of 5.0 FPs/image. When the authors used a database developed at the University of Chicago, the sensitivities was 83.3% (40/48) and 77.1% (37/48) at an FP rate of 5.0 (240/48) FPs/image and 2.0 (96/48) FPs /image, respectively. Conclusions: These results compare favorably to those described for

  20. [Early detection of addictive behaviour in primary health care. Use of MULTICAGE CAD-4].

    Science.gov (United States)

    Rodríguez Monje, M Teresa; Pedrero Pérez, Eduardo J; Fernández Girón, Mercedes; Gallardo Alonso, Fernando; Sanz Cuesta, Teresa

    2009-01-01

    To find out the frequency of specific disorders within the general population using primary healthcare relating to the control of impulses with addictive risk. A cross-sectional descriptive study. Urban health centre, Area 9 of the Madrid Health Service (Spain). A total of 457 patients who came to primary care (PA) were selected by consecutive sampling. Self-completion of the MULTICAGE-CAD4 survey (which measure eight scales for the risky behaviour being studied). There was a risk in at least one of the scales in 46.4% of the sample, of which 17.3% (13.7-20.9) showed risky behaviour on the alcohol scale; 9% (6.2-11.7) for other drugs; 4.4% (2.4-6.4) for gambling; 9.4% (6.6-12.2) for addiction to the Internet; 4.8% (2.7-6.7) for addiction to videogames; 18.8% (15.1-22.5) for eating disorders; 16% (12.5-19.4) for compulsive shopping and 5.5% (3.3-7.7) for addiction to sex. The occurrence of addiction to alcohol, gambling and sex were higher for men, while eating disorders were more prevalent in women. We are facing a widespread set of problems related to addictions that are often hidden; this study shows that these addictions can be detected within primary healthcare by effective screening tools such as MULTICAGE CAD-4, which is both economic, and easy to implement within primary healthcare centres.

  1. A comparison of computer-assisted detection (CAD) programs for the identification of colorectal polyps: performance and sensitivity analysis, current limitations and practical tips for radiologists.

    Science.gov (United States)

    Bell, L T O; Gandhi, S

    2018-06-01

    To directly compare the accuracy and speed of analysis of two commercially available computer-assisted detection (CAD) programs in detecting colorectal polyps. In this retrospective single-centre study, patients who had colorectal polyps identified on computed tomography colonography (CTC) and subsequent lower gastrointestinal endoscopy, were analysed using two commercially available CAD programs (CAD1 and CAD2). Results were compared against endoscopy to ascertain sensitivity and positive predictive value (PPV) for colorectal polyps. Time taken for CAD analysis was also calculated. CAD1 demonstrated a sensitivity of 89.8%, PPV of 17.6% and mean analysis time of 125.8 seconds. CAD2 demonstrated a sensitivity of 75.5%, PPV of 44.0% and mean analysis time of 84.6 seconds. The sensitivity and PPV for colorectal polyps and CAD analysis times can vary widely between current commercially available CAD programs. There is still room for improvement. Generally, there is a trade-off between sensitivity and PPV, and so further developments should aim to optimise both. Information on these factors should be made routinely available, so that an informed choice on their use can be made. This information could also potentially influence the radiologist's use of CAD results. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  2. The CAD concept for stellarator-type magnetic systems

    International Nuclear Information System (INIS)

    Vorobyova, V.P.; Martynov, S.A.; Khazhmuradov, M.A.

    2002-01-01

    The paper describes the computer-aided design (CAD) concept for stellarator-type magnetic systems. Consideration is given to the main peculiarities, principles, and dialog organization and design stages of the CAD. The practical realization of the concept is illustrated by specific examples

  3. Computer-aided dispatching system design specification

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, M.G.

    1997-12-16

    This document defines the performance requirements for a graphic display dispatching system to support Hanford Patrol Operations Center. This document reflects the as-built requirements for the system that was delivered by GTE Northwest, Inc. This system provided a commercial off-the-shelf computer-aided dispatching system and alarm monitoring system currently in operations at the Hanford Patrol Operations Center, Building 2721E. This system also provides alarm back-up capability for the Plutonium Finishing Plant (PFP).

  4. Computer-aided dispatching system design specification

    International Nuclear Information System (INIS)

    Briggs, M.G.

    1997-01-01

    This document defines the performance requirements for a graphic display dispatching system to support Hanford Patrol Operations Center. This document reflects the as-built requirements for the system that was delivered by GTE Northwest, Inc. This system provided a commercial off-the-shelf computer-aided dispatching system and alarm monitoring system currently in operations at the Hanford Patrol Operations Center, Building 2721E. This system also provides alarm back-up capability for the Plutonium Finishing Plant (PFP)

  5. [Contribution of computer-aided design for the conception of custom-made implants in Pectus Excavatum surgical treatment. Experience of the Nantes plastic surgery unit].

    Science.gov (United States)

    Tilliet Le Dentu, H; Lancien, U; Sellal, O; Duteille, F; Perrot, P

    2018-02-01

    Pectus excavatum is the most common congenital chest malformation and is a common reason for consultation in plastic surgery. Our attitude is most often a filling of the depression with a custom-made silicone prosthesis. The objective of this work was to evaluate the interest of computer-aided design (CAD) of implants compared to the conventional plaster molds method. We have collected all the cases of custom-made silicone implants to treat funnel chests in our plastic surgery department. The quality of the results was evaluated by the patient, and in a blind manner by the surgical team using photographs and standardized surveys. The pre-operative delays, the operating time and length of hospital stays, the number of surgical recoveries, and the post-operative surgical outcomes were recorded. Between 1990 and 2016, we designed 29 silicone thoracic implants in our department. Before 2012, implants were made from plaster chest molds (n=13). After this date, implants were designed by CAD (n=16). Patients rated their results as "good" or "excellent" in 77% and 86% of cases respectively in the plaster and CAD groups. The surgical team's ratings for CAD implant reconstructions were better than in the plaster group: 8.17 versus 6.96 (P=0.001). CAD implants were significantly less detectable than the plaster group implants. The operating time was reduced in the CAO group: 60.2 compared to 74.7minutes in the plaster group (P=0.04), as was the length of hospitalization: 3.5 versus 5.3 days (P=0.01). There were no significant differences between the two groups in terms of post-operative complications. The management of pectus excavatum by a custom-made silicone implant is a minimally invasive method that provides good cosmetic results. The design of these implants is facilitated and qualitatively improved by CAD. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. A Case Study in CAD Design Automation

    Science.gov (United States)

    Lowe, Andrew G.; Hartman, Nathan W.

    2011-01-01

    Computer-aided design (CAD) software and other product life-cycle management (PLM) tools have become ubiquitous in industry during the past 20 years. Over this time they have continuously evolved, becoming programs with enormous capabilities, but the companies that use them have not evolved their design practices at the same rate. Due to the…

  7. Mammogram CAD, hybrid registration and iconic analysis

    Science.gov (United States)

    Boucher, A.; Cloppet, F.; Vincent, N.

    2013-03-01

    This paper aims to develop a computer aided diagnosis (CAD) based on a two-step methodology to register and analyze pairs of temporal mammograms. The concept of "medical file", including all the previous medical information on a patient, enables joint analysis of different acquisitions taken at different times, and the detection of significant modifications. The developed registration method aims to superimpose at best the different anatomical structures of the breast. The registration is designed in order to get rid of deformation undergone by the acquisition process while preserving those due to breast changes indicative of malignancy. In order to reach this goal, a referent image is computed from control points based on anatomical features that are extracted automatically. Then the second image of the couple is realigned on the referent image, using a coarse-to-fine approach according to expert knowledge that allows both rigid and non-rigid transforms. The joint analysis detects the evolution between two images representing the same scene. In order to achieve this, it is important to know the registration error limits in order to adapt the observation scale. The approach used in this paper is based on an image sparse representation. Decomposed in regular patterns, the images are analyzed under a new angle. The evolution detection problem has many practical applications, especially in medical images. The CAD is evaluated using recall and precision of differences in mammograms.

  8. Computer-aided diagnosis of liver tumors on computed tomography images.

    Science.gov (United States)

    Chang, Chin-Chen; Chen, Hong-Hao; Chang, Yeun-Chung; Yang, Ming-Yang; Lo, Chung-Ming; Ko, Wei-Chun; Lee, Yee-Fan; Liu, Kao-Lang; Chang, Ruey-Feng

    2017-07-01

    Liver cancer is the tenth most common cancer in the USA, and its incidence has been increasing for several decades. Early detection, diagnosis, and treatment of the disease are very important. Computed tomography (CT) is one of the most common and robust imaging techniques for the detection of liver cancer. CT scanners can provide multiple-phase sequential scans of the whole liver. In this study, we proposed a computer-aided diagnosis (CAD) system to diagnose liver cancer using the features of tumors obtained from multiphase CT images. A total of 71 histologically-proven liver tumors including 49 benign and 22 malignant lesions were evaluated with the proposed CAD system to evaluate its performance. Tumors were identified by the user and then segmented using a region growing algorithm. After tumor segmentation, three kinds of features were obtained for each tumor, including texture, shape, and kinetic curve. The texture was quantified using 3 dimensional (3-D) texture data of the tumor based on the grey level co-occurrence matrix (GLCM). Compactness, margin, and an elliptic model were used to describe the 3-D shape of the tumor. The kinetic curve was established from each phase of tumor and represented as variations in density between each phase. Backward elimination was used to select the best combination of features, and binary logistic regression analysis was used to classify the tumors with leave-one-out cross validation. The accuracy and sensitivity for the texture were 71.82% and 68.18%, respectively, which were better than for the shape and kinetic curve under closed specificity. Combining all of the features achieved the highest accuracy (58/71, 81.69%), sensitivity (18/22, 81.82%), and specificity (40/49, 81.63%). The Az value of combining all features was 0.8713. Combining texture, shape, and kinetic curve features may be able to differentiate benign from malignant tumors in the liver using our proposed CAD system. Copyright © 2017 Elsevier B.V. All

  9. [Three-dimensional computer aided design for individualized post-and-core restoration].

    Science.gov (United States)

    Gu, Xiao-yu; Wang, Ya-ping; Wang, Yong; Lü, Pei-jun

    2009-10-01

    To develop a method of three-dimensional computer aided design (CAD) of post-and-core restoration. Two plaster casts with extracted natural teeth were used in this study. The extracted teeth were prepared and scanned using tomography method to obtain three-dimensional digitalized models. According to the basic rules of post-and-core design, posts, cores and cavity surfaces of the teeth were designed using the tools for processing point clouds, curves and surfaces on the forward engineering software of Tanglong prosthodontic system. Then three-dimensional figures of the final restorations were corrected according to the configurations of anterior teeth, premolars and molars respectively. Computer aided design of 14 post-and-core restorations were finished, and good fitness between the restoration and the three-dimensional digital models were obtained. Appropriate retention forms and enough spaces for the full crown restorations can be obtained through this method. The CAD of three-dimensional figures of the post-and-core restorations can fulfill clinical requirements. Therefore they can be used in computer-aided manufacture (CAM) of post-and-core restorations.

  10. Secondary Maxillary and Orbital Floor Reconstruction With a Free Scapular Flap Using Cutting and Fixation Guides Created by Computer-Aided Design/Computer-Aided Manufacturing.

    Science.gov (United States)

    Morita, Daiki; Numajiri, Toshiaki; Tsujiko, Shoko; Nakamura, Hiroko; Yamochi, Ryo; Sowa, Yoshihiro; Yasuda, Makoto; Hirano, Shigeru

    2017-11-01

    Computer-aided design/computer-aided manufacturing (CAD/CAM) guides are now widely used in maxillofacial reconstruction. However, there are few reports of CAD/CAM guides being used for scapular flaps. The authors performed the secondary maxillary and orbital floor reconstruction using a free latissimus dorsi muscle, cutaneous tissue, and scapular flap designed using CAD/CAM techniques in a 72-year-old man who had undergone partial maxillectomy four years previously. The patient had diplopia, the vertical dystopia of eye position, and a large oral-nasal-cutaneous fistula. After the operation, the authors confirmed that the deviation between the postoperative and preoperative planning three-dimensional images was less than 2 mm. Because scapular guides require 3 cutting surfaces, the shape of the scapular guide is more complex than that of a conventional fibular guide. In orbital floor reconstruction, the use of a CAM technique such as that used to manufacture the authors' fixation guide is as necessary for accurate, safe, and easy reconstruction as is preoperative CAD planning. The production of a fixation guide as well as a cutting guide is particularly useful because it is difficult to determine the angle for reconstructing the orbital floor by freehand techniques. In this case, the orbital floor was reconstructed based on a mirror image of the healthy side to avoid overcompression of the orbital tissue. Although the patient's vertical dystopia of eye position was improved, diplopia was not improved because, for greater safety, the authors did not plan overcorrection of the orbital volume.

  11. Computer-aided diagnosis for classifying benign versus malignant thyroid nodules based on ultrasound images: A comparison with radiologist-based assessments

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yongjun [School of Electrical Engineering, Korea Advanced Institute of Science and Technology, 291, Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Paul, Anjan Kumar [Funzin, Inc., 148 Ankuk-dong, Jongro-gu, Seoul 03060 (Korea, Republic of); Kim, Namkug, E-mail: namkugkim@gmail.com; Baek, Jung Hwan; Choi, Young Jun [Department of Radiology, University of Ulsan College of Medicine, 388-1 Pungnap2-dong, Songpa-gu, Seoul 05505 (Korea, Republic of); Ha, Eun Ju [Department of Radiology, Ajou University School of Medicine, Wonchon-Dong, Yeongtong-Gu, Suwon 16499 (Korea, Republic of); Lee, Kang Dae; Lee, Hyoung Shin [Department of Otolaryngology Head and Neck Surgery, Kosin University College of Medicine, 34 Amnamdong, Seu-Gu, Busan 49267 (Korea, Republic of); Shin, DaeSeock; Kim, Nakyoung [MIDAS Information Technology, Pangyo-ro 228, Bundang-gu, Seongnam-si, Gyeonggi 13487 (Korea, Republic of)

    2016-01-15

    Purpose: To develop a semiautomated computer-aided diagnosis (CAD) system for thyroid cancer using two-dimensional ultrasound images that can be used to yield a second opinion in the clinic to differentiate malignant and benign lesions. Methods: A total of 118 ultrasound images that included axial and longitudinal images from patients with biopsy-confirmed malignant (n = 30) and benign (n = 29) nodules were collected. Thyroid CAD software was developed to extract quantitative features from these images based on thyroid nodule segmentation in which adaptive diffusion flow for active contours was used. Various features, including histogram, intensity differences, elliptical fit, gray-level co-occurrence matrixes, and gray-level run-length matrixes, were evaluated for each region imaged. Based on these imaging features, a support vector machine (SVM) classifier was used to differentiate benign and malignant nodules. Leave-one-out cross-validation with sequential forward feature selection was performed to evaluate the overall accuracy of this method. Additionally, analyses with contingency tables and receiver operating characteristic (ROC) curves were performed to compare the performance of CAD with visual inspection by expert radiologists based on established gold standards. Results: Most univariate features for this proposed CAD system attained accuracies that ranged from 78.0% to 83.1%. When optimal SVM parameters that were established using a grid search method with features that radiologists use for visual inspection were employed, the authors could attain rates of accuracy that ranged from 72.9% to 84.7%. Using leave-one-out cross-validation results in a multivariate analysis of various features, the highest accuracy achieved using the proposed CAD system was 98.3%, whereas visual inspection by radiologists reached 94.9% accuracy. To obtain the highest accuracies, “axial ratio” and “max probability” in axial images were most frequently included in the

  12. Speech-enabled Computer-aided Translation

    DEFF Research Database (Denmark)

    Mesa-Lao, Bartolomé

    2014-01-01

    The present study has surveyed post-editor trainees’ views and attitudes before and after the introduction of speech technology as a front end to a computer-aided translation workbench. The aim of the survey was (i) to identify attitudes and perceptions among post-editor trainees before performing...... a post-editing task using automatic speech recognition (ASR); and (ii) to assess the degree to which post-editors’ attitudes and expectations to the use of speech technology changed after actually using it. The survey was based on two questionnaires: the first one administered before the participants...

  13. Computer-aided power systems analysis

    CERN Document Server

    Kusic, George

    2008-01-01

    Computer applications yield more insight into system behavior than is possible by using hand calculations on system elements. Computer-Aided Power Systems Analysis: Second Edition is a state-of-the-art presentation of basic principles and software for power systems in steady-state operation. Originally published in 1985, this revised edition explores power systems from the point of view of the central control facility. It covers the elements of transmission networks, bus reference frame, network fault and contingency calculations, power flow on transmission networks, generator base power setti

  14. Computer aided plant engineering: An analysis and suggestions for computer use

    International Nuclear Information System (INIS)

    Leinemann, K.

    1979-09-01

    To get indications to and boundary conditions for computer use in plant engineering, an analysis of the engineering process was done. The structure of plant engineering is represented by a network of substaks and subsets of data which are to be manipulated. Main tool for integration of CAD-subsystems in plant engineering should be a central database which is described by characteristical requirements and a possible simple conceptual schema. The main features of an interactive system for computer aided plant engineering are shortly illustrated by two examples. The analysis leads to the conclusion, that an interactive graphic system for manipulation of net-like structured data, usable for various subtasks, should be the base for computer aided plant engineering. (orig.) [de

  15. Computer-Aided Design Method of Warp-Knitted Jacquard Spacer Fabrics

    Directory of Open Access Journals (Sweden)

    Li Xinxin

    2016-06-01

    Full Text Available Based on a further study on knitting and jacquard principles, this paper presents a mathematical design model to make computer-aided design of warp-knitted jacquard spacer fabrics more efficient. The mathematical model with matrix method employs three essential elements of chain notation, threading and Jacquard designing. With this model, the processing to design warp-knitted jacquard spacer fabrics with CAD software is also introduced. In this study, the sports shoes which have separated functional areas according to the feet structure and characteristics of movement are analysed. The results show the different patterns on Jacquard spacer fabrics that are seamlessly stitched with jacquard technics. The computer-aided design method of warp-knitted jacquard spacer fabrics is efficient and simple.

  16. Computer aided virtual manufacturing using Creo parametric easy to learn step by step guide

    CERN Document Server

    Kanife, Paul Obiora

    2016-01-01

    Providing a step-by-step guide for the implementation of virtual manufacturing using Creo Parametric software (formerly known as Pro-Engineer), this book creates an engaging and interactive learning experience for manufacturing engineering students. Featuring graphic illustrations of simulation processes and operations, and written in accessible English to promote user-friendliness, the book covers key topics in the field including: the engraving machining process, face milling, profile milling, surface milling, volume rough milling, expert machining, electric discharge machining (EDM), and area turning using the lathe machining process. Maximising reader insights into how to simulate material removal processes, and how to generate cutter location data and G-codes data, this valuable resource equips undergraduate, postgraduate, BTech and HND students in the fields of manufacturing engineering, computer aided design (CAD) and computer aided engineering (CAE) with transferable skills and knowledge. This book is...

  17. Decision trees and integrated features for computer aided mammographic screening

    Energy Technology Data Exchange (ETDEWEB)

    Kegelmeyer, W.P. Jr.; Groshong, B.; Allmen, M.; Woods, K.

    1997-02-01

    Breast cancer is a serious problem, which in the United States causes 43,000 deaths a year, eventually striking 1 in 9 women. Early detection is the only effective countermeasure, and mass mammography screening is the only reliable means for early detection. Mass screening has many shortcomings which could be addressed by a computer-aided mammographic screening system. Accordingly, we have applied the pattern recognition methods developed in earlier investigations of speculated lesions in mammograms to the detection of microcalcifications and circumscribed masses, generating new, more rigorous and uniform methods for the detection of both those signs. We have also improved the pattern recognition methods themselves, through the development of a new approach to combinations of multiple classifiers.

  18. Evaluation of marginal/internal fit of chrome-cobalt crowns: Direct laser metal sintering versus computer-aided design and computer-aided manufacturing.

    Science.gov (United States)

    Gunsoy, S; Ulusoy, M

    2016-01-01

    The purpose of this study was to evaluate the internal and marginal fit of chrome cobalt (Co-Cr) crowns were fabricated with laser sintering, computer-aided design (CAD) and computer-aided manufacturing, and conventional methods. Polyamide master and working models were designed and fabricated. The models were initially designed with a software application for three-dimensional (3D) CAD (Maya, Autodesk Inc.). All models were fabricated models were produced by a 3D printer (EOSINT P380 SLS, EOS). 128 1-unit Co-Cr fixed dental prostheses were fabricated with four different techniques: Conventional lost wax method, milled wax with lost-wax method (MWLW), direct laser metal sintering (DLMS), and milled Co-Cr (MCo-Cr). The cement film thickness of the marginal and internal gaps was measured by an observer using a stereomicroscope after taking digital photos in ×24. Best fit rates according to mean and standard deviations of all measurements was in DLMS both in premolar (65.84) and molar (58.38) models in μm. A significant difference was found DLMS and the rest of fabrication techniques (P 0.05). DMLS was best fitting fabrication techniques for single crown based on the results.The best fit was found in marginal; the larger gap was found in occlusal.All groups were within the clinically acceptable misfit range.

  19. Computer aided system engineering for space construction

    Science.gov (United States)

    Racheli, Ugo

    1989-01-01

    This viewgraph presentation covers the following topics. Construction activities envisioned for the assembly of large platforms in space (as well as interplanetary spacecraft and bases on extraterrestrial surfaces) require computational tools that exceed the capability of conventional construction management programs. The Center for Space Construction is investigating the requirements for new computational tools and, at the same time, suggesting the expansion of graduate and undergraduate curricula to include proficiency in Computer Aided Engineering (CAE) though design courses and individual or team projects in advanced space systems design. In the center's research, special emphasis is placed on problems of constructability and of the interruptability of planned activity sequences to be carried out by crews operating under hostile environmental conditions. The departure point for the planned work is the acquisition of the MCAE I-DEAS software, developed by the Structural Dynamics Research Corporation (SDRC), and its expansion to the level of capability denoted by the acronym IDEAS**2 currently used for configuration maintenance on Space Station Freedom. In addition to improving proficiency in the use of I-DEAS and IDEAS**2, it is contemplated that new software modules will be developed to expand the architecture of IDEAS**2. Such modules will deal with those analyses that require the integration of a space platform's configuration with a breakdown of planned construction activities and with a failure modes analysis to support computer aided system engineering (CASE) applied to space construction.

  20. Computer- Aided diagnosis system for the evaluation of chronic obstructive pulmonary disease on CT Images

    Directory of Open Access Journals (Sweden)

    Parsa Hosseini M

    2011-03-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Chronic Obstructive Pulmonary Disease (COPD is one of the most prevalent pulmonary diseases. Use of an automatic system for the detection and diagnosis of the disease will be beneficial to the patients' treatment decision-making process. In this paper, we propose a new approach for the Computer Aided Diagnosis (CAD of the disease and determination of its severity axial CT scan images."n"nMethods: In this study, 24 lung CT scans in full inspiratory and expiratory states were performed. Variations in the normalized pattern of the lungs' external parenchyma were exploited as a feature for COPD diagnosis. Subsequently, a Bayesian classifier was used to classify variations into two normal and abnormal patterns for the discrimination of patients and healthy individuals. Finally, the accuracy of the classification was assessed statistically. "n"nResults: With the proposed method, the lungs parenchymal elasticity and air-trapping were determined quantitatively. The more this feature tended to zero, the more severe air-trapping and obstructive pulmonary disease is. By analyzing CT images in the healthy and patient groups, we calculated the hard threshold for the diagnosis of the disease. Clinical results

  1. Computer-Aided Diagnosis Based on Convolutional Neural Network System for Colorectal Polyp Classification: Preliminary Experience.

    Science.gov (United States)

    Komeda, Yoriaki; Handa, Hisashi; Watanabe, Tomohiro; Nomura, Takanobu; Kitahashi, Misaki; Sakurai, Toshiharu; Okamoto, Ayana; Minami, Tomohiro; Kono, Masashi; Arizumi, Tadaaki; Takenaka, Mamoru; Hagiwara, Satoru; Matsui, Shigenaga; Nishida, Naoshi; Kashida, Hiroshi; Kudo, Masatoshi

    2017-01-01

    Computer-aided diagnosis (CAD) is becoming a next-generation tool for the diagnosis of human disease. CAD for colon polyps has been suggested as a particularly useful tool for trainee colonoscopists, as the use of a CAD system avoids the complications associated with endoscopic resections. In addition to conventional CAD, a convolutional neural network (CNN) system utilizing artificial intelligence (AI) has been developing rapidly over the past 5 years. We attempted to generate a unique CNN-CAD system with an AI function that studied endoscopic images extracted from movies obtained with colonoscopes used in routine examinations. Here, we report our preliminary results of this novel CNN-CAD system for the diagnosis of colon polyps. A total of 1,200 images from cases of colonoscopy performed between January 2010 and December 2016 at Kindai University Hospital were used. These images were extracted from the video of actual endoscopic examinations. Additional video images from 10 cases of unlearned processes were retrospectively assessed in a pilot study. They were simply diagnosed as either an adenomatous or nonadenomatous polyp. The number of images used by AI to learn to distinguish adenomatous from nonadenomatous was 1,200:600. These images were extracted from the videos of actual endoscopic examinations. The size of each image was adjusted to 256 × 256 pixels. A 10-hold cross-validation was carried out. The accuracy of the 10-hold cross-validation is 0.751, where the accuracy is the ratio of the number of correct answers over the number of all the answers produced by the CNN. The decisions by the CNN were correct in 7 of 10 cases. A CNN-CAD system using routine colonoscopy might be useful for the rapid diagnosis of colorectal polyp classification. Further prospective studies in an in vivo setting are required to confirm the effectiveness of a CNN-CAD system in routine colonoscopy. © 2017 S. Karger AG, Basel.

  2. Computer-aided ultrasonic inspection of steam turbine rotors

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K.H.; Weber, M.; Weiss, M. [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1998-12-31

    As the output and economic value of power plants increase, the detection and sizing of the type of flaws liable to occur in the rotors of turbines using ultrasonic methods assumes increasing importance. An ultrasonic inspection carried out at considerable expense is expected to bring to light all safety-relevant flaws and to enable their size to be determined so as to permit a fracture-mechanics analysis to assess the reliability of the rotor under all possible stresses arising in operation with a high degree of accuracy. The advanced computer-aided ultrasonic inspection of steam turbine rotors have improved reliability, accuracy and reproducibility of ultrasonic inspection. Further, there has been an improvement in the resolution of resolvable group indications by applying reconstruction and imagine methods. In general, it is also true for the advanced computer-aided ultrasonic inspection methods that, in the case of flaw-affected forgings, automated data acquisition provides a substantial rationalization and a significant documentation of the results for the fracture mechanics assessment compared to manual inspection. (orig.) 8 refs.

  3. Computer-aided ultrasonic inspection of steam turbine rotors

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, K H; Weber, M; Weiss, M [GEC ALSTHOM Energie GmbH, Nuremberg (Germany)

    1999-12-31

    As the output and economic value of power plants increase, the detection and sizing of the type of flaws liable to occur in the rotors of turbines using ultrasonic methods assumes increasing importance. An ultrasonic inspection carried out at considerable expense is expected to bring to light all safety-relevant flaws and to enable their size to be determined so as to permit a fracture-mechanics analysis to assess the reliability of the rotor under all possible stresses arising in operation with a high degree of accuracy. The advanced computer-aided ultrasonic inspection of steam turbine rotors have improved reliability, accuracy and reproducibility of ultrasonic inspection. Further, there has been an improvement in the resolution of resolvable group indications by applying reconstruction and imagine methods. In general, it is also true for the advanced computer-aided ultrasonic inspection methods that, in the case of flaw-affected forgings, automated data acquisition provides a substantial rationalization and a significant documentation of the results for the fracture mechanics assessment compared to manual inspection. (orig.) 8 refs.

  4. De CAD/CAM-brug vervaardigd met behulp van een composiet mock-up

    NARCIS (Netherlands)

    Denissen, H.; Đozic, A.

    2010-01-01

    Het esthetische aspect van een brugconstructie in het front is niet altijd voorspelbaar. Dit geldt voor zowel conventionele bruggen als bruggen die computerondersteund worden ontworpen (computer-aided design, cad ) en geproduceerd (computer-aided manufacturing, cam ). Een cruciale factor is het

  5. Process and Tool Innovation for CAD Integration with OLTARIS, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA uses computer aided design (CAD) capabilities to produce space vehicle designs. One aspect of the vehicle design is utilizing enough shielding to minimize dose...

  6. Process and Tool Innovation for CAD Integration with OLTARIS, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA uses computer aided design (CAD) capabilities to produce space vehicle designs. One aspect of the vehicle design is utilizing enough shielding to minimize dose...

  7. [Initial evolution research for design and process accuracy of one type of domestic computer aided design soft and computer aided manufacture].

    Science.gov (United States)

    Song, Yang; Zhao, Yi-jiao; Sun, Yu-chun; Lü, Pei-jun; Wang, Yong

    2013-09-01

    To evaluate the design and manufacture accuracy of a domestic computer aided design (CAD) and computer aided manufacture (CAM) system, and to compare it with similar foreign products. Thirty models of posterior-teeth-single-crown preparations were collected, and STL data of these preparations was collected by Denmark 3Shape scanner. Three copings were made for each preparation, the one designed and manufactured using commercial CAD/CAM system (3Shape CAD software and Wieland T1 CAM equipment) was assigned into control group T0, the one designed and manufactured using domestic CAD software (developed by Peking University School and Hospital of Stomatology and Nanjing University of Aeronautics and Astronautics) and Wieland T1 CAM equipment was assigned into experimental group TCAD for design accuracy evaluation, and the one designed and manufactured using 3Shape CAD software and domestic CAM equipment (developed by Peking University School and Hospital of Stomatology, Tsinghua University and ShanDong XinHua Incorporated Company of medical apparatus and instruments) was assigned into experimental group TCAM for manufacture accuracy evaluation. Finally, the marginal fitness were compared and evaluated by using 3D & Profile measurement microscope laser. The marginal fitness of TCAD was 27.98 (19.10, 46.57) µm in buccal, 32.67 (20.65, 50.82) µm in lingual, 27.38 (22.53, 52.61) µm in mesial, 29.50 (22.68, 53.65) µm in distal; of TCAM was 21.69 (15.87, 30.21) µm in buccal, 18.51 (13.50, 22.51) µm in lingual, 19.15 (15.42, 26.89) µm in mesial, 22.77 (18.58, 32.15) µm in distal; and there were no statistical differences compared with T0 [20.16 (17.16, 48.00) µm in buccal, 21.51 (17.05, 28.31) µm in lingual, 23.54 (17.89, 30.04) µm in mesial and 23.94 (17.93, 28.19) µm in distal] except lingual data of TCAD. The design and machining precision of this domestic CAD/CAM system is at the same level of those comparable foreign products.

  8. Toward clinically usable CAD for lung cancer screening with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Matthew S.; Lo, Pechin; Goldin, Jonathan G.; Barnoy, Eran; Kim, Grace Hyun J.; McNitt-Gray, Michael F.; Aberle, Denise R. [David Geffen School of Medicine at UCLA, Center for Computer Vision and Imaging Biomarkers, Department of Radiological Sciences, Los Angeles, CA (United States)

    2014-11-15

    The purpose of this study was to define clinically appropriate, computer-aided lung nodule detection (CAD) requirements and protocols based on recent screening trials. In the following paper, we describe a CAD evaluation methodology based on a publically available, annotated computed tomography (CT) image data set, and demonstrate the evaluation of a new CAD system with the functionality and performance required for adoption in clinical practice. A new automated lung nodule detection and measurement system was developed that incorporates intensity thresholding, a Euclidean Distance Transformation, and segmentation based on watersheds. System performance was evaluated against the Lung Imaging Database Consortium (LIDC) CT reference data set. The test set comprised thin-section CT scans from 108 LIDC subjects. The median (±IQR) sensitivity per subject was 100 (±37.5) for nodules ≥ 4 mm and 100 (±8.33) for nodules ≥ 8 mm. The corresponding false positive rates were 0 (±2.0) and 0 (±1.0), respectively. The concordance correlation coefficient between the CAD nodule diameter and the LIDC reference was 0.91, and for volume it was 0.90. The new CAD system shows high nodule sensitivity with a low false positive rate. Automated volume measurements have strong agreement with the reference standard. Thus, it provides comprehensive, clinically-usable lung nodule detection and assessment functionality. (orig.)

  9. Toward clinically usable CAD for lung cancer screening with computed tomography

    International Nuclear Information System (INIS)

    Brown, Matthew S.; Lo, Pechin; Goldin, Jonathan G.; Barnoy, Eran; Kim, Grace Hyun J.; McNitt-Gray, Michael F.; Aberle, Denise R.

    2014-01-01

    The purpose of this study was to define clinically appropriate, computer-aided lung nodule detection (CAD) requirements and protocols based on recent screening trials. In the following paper, we describe a CAD evaluation methodology based on a publically available, annotated computed tomography (CT) image data set, and demonstrate the evaluation of a new CAD system with the functionality and performance required for adoption in clinical practice. A new automated lung nodule detection and measurement system was developed that incorporates intensity thresholding, a Euclidean Distance Transformation, and segmentation based on watersheds. System performance was evaluated against the Lung Imaging Database Consortium (LIDC) CT reference data set. The test set comprised thin-section CT scans from 108 LIDC subjects. The median (±IQR) sensitivity per subject was 100 (±37.5) for nodules ≥ 4 mm and 100 (±8.33) for nodules ≥ 8 mm. The corresponding false positive rates were 0 (±2.0) and 0 (±1.0), respectively. The concordance correlation coefficient between the CAD nodule diameter and the LIDC reference was 0.91, and for volume it was 0.90. The new CAD system shows high nodule sensitivity with a low false positive rate. Automated volume measurements have strong agreement with the reference standard. Thus, it provides comprehensive, clinically-usable lung nodule detection and assessment functionality. (orig.)

  10. Clinical evaluation of a computer-aided diagnosis system for determining cancer aggressiveness in prostate MRI

    International Nuclear Information System (INIS)

    Litjens, Geert J.S.; Barentsz, Jelle O.; Karssemeijer, Nico; Huisman, Henkjan J.

    2015-01-01

    To investigate the added value of computer-aided diagnosis (CAD) on the diagnostic accuracy of PIRADS reporting and the assessment of cancer aggressiveness. Multi-parametric MRI and histopathological outcome of MR-guided biopsies of a consecutive set of 130 patients were included. All cases were prospectively PIRADS reported and the reported lesions underwent CAD analysis. Logistic regression combined the CAD prediction and radiologist PIRADS score into a combination score. Receiver-operating characteristic (ROC) analysis and Spearman's correlation coefficient were used to assess the diagnostic accuracy and correlation to cancer grade. Evaluation was performed for discriminating benign lesions from cancer and for discriminating indolent from aggressive lesions. In total 141 lesions (107 patients) were included for final analysis. The area-under-the-ROC-curve of the combination score was higher than for the PIRADS score of the radiologist (benign vs. cancer, 0.88 vs. 0.81, p = 0.013 and indolent vs. aggressive, 0.88 vs. 0.78, p < 0.01). The combination score correlated significantly stronger with cancer grade (0.69, p = 0.0014) than the individual CAD system or radiologist (0.54 and 0.58). Combining CAD prediction and PIRADS into a combination score has the potential to improve diagnostic accuracy. Furthermore, such a combination score has a strong correlation with cancer grade. (orig.)

  11. Computer-Aided Drug Design in Epigenetics

    Directory of Open Access Journals (Sweden)

    Wenchao Lu

    2018-03-01

    Full Text Available Epigenetic dysfunction has been widely implicated in several diseases especially cancers thus highlights the therapeutic potential for chemical interventions in this field. With rapid development of computational methodologies and high-performance computational resources, computer-aided drug design has emerged as a promising strategy to speed up epigenetic drug discovery. Herein, we make a brief overview of major computational methods reported in the literature including druggability prediction, virtual screening, homology modeling, scaffold hopping, pharmacophore modeling, molecular dynamics simulations, quantum chemistry calculation, and 3D quantitative structure activity relationship that have been successfully applied in the design and discovery of epi-drugs and epi-probes. Finally, we discuss about major limitations of current virtual drug design strategies in epigenetics drug discovery and future directions in this field.

  12. Computer-Aided Drug Design in Epigenetics

    Science.gov (United States)

    Lu, Wenchao; Zhang, Rukang; Jiang, Hao; Zhang, Huimin; Luo, Cheng

    2018-01-01

    Epigenetic dysfunction has been widely implicated in several diseases especially cancers thus highlights the therapeutic potential for chemical interventions in this field. With rapid development of computational methodologies and high-performance computational resources, computer-aided drug design has emerged as a promising strategy to speed up epigenetic drug discovery. Herein, we make a brief overview of major computational methods reported in the literature including druggability prediction, virtual screening, homology modeling, scaffold hopping, pharmacophore modeling, molecular dynamics simulations, quantum chemistry calculation, and 3D quantitative structure activity relationship that have been successfully applied in the design and discovery of epi-drugs and epi-probes. Finally, we discuss about major limitations of current virtual drug design strategies in epigenetics drug discovery and future directions in this field. PMID:29594101

  13. Computer-Aided Drug Design in Epigenetics

    Science.gov (United States)

    Lu, Wenchao; Zhang, Rukang; Jiang, Hao; Zhang, Huimin; Luo, Cheng

    2018-03-01

    Epigenetic dysfunction has been widely implicated in several diseases especially cancers thus highlights the therapeutic potential for chemical interventions in this field. With rapid development of computational methodologies and high-performance computational resources, computer-aided drug design has emerged as a promising strategy to speed up epigenetic drug discovery. Herein, we make a brief overview of major computational methods reported in the literature including druggability prediction, virtual screening, homology modeling, scaffold hopping, pharmacophore modeling, molecular dynamics simulations, quantum chemistry calculation and 3D quantitative structure activity relationship that have been successfully applied in the design and discovery of epi-drugs and epi-probes. Finally, we discuss about major limitations of current virtual drug design strategies in epigenetics drug discovery and future directions in this field.

  14. Computer-Aided Design of Antimicrobial Peptides

    DEFF Research Database (Denmark)

    Fjell, Christopher D.; Hancock, Robert E.W.; Jenssen, Håvard

    2010-01-01

    in antimicrobial activity. Consequently, the majority of peptides put into clinical trials have failed at some point, underlining the importance of a thorough peptide optimization. An important tool in peptide design and optimization is quantitative structure-activity relationship (QSAR) analysis, correlating...... chemical parameters with biological activities of the peptide, using statistical methods. In this review we will discuss two different in silico strategies of computer-aided antibacterial peptide design, a linear correlation model build as an extension of traditional principal component analysis (PCA......) and a non-linear artificial neural network model. Studies on structurally diverse peptides, have concluded that the PCA derived model are able to guide the antibacterial peptide design in a meaningful way, however requiring rather a high homology between the peptides in the test-set and the in silico...

  15. A Preliminary Study on the Effect of Computer-Aided Designed and Manufactured Orthoses on Chronic Plantar Heel Pain.

    Science.gov (United States)

    Gatt, Alfred; Grech, Mark; Chockalingam, Nachiappan; Formosa, Cynthia

    2018-04-01

    Chronic plantar heel pain (CPHP) is a significant, painful condition referring to a range of undifferentiated foot conditions that affect the heel of the foot. Participants presenting with CPHP of more than 6 months' duration were recruited on a first through the door basis. Computer-Aided Design and Computer-Aided Manufactured (CAD-CAM) orthoses were designed and constructed for each participant, then dispensed as per normal practice. Pre- and postintervention assessment of pain was performed at baseline and after 6 weeks of use, utilizing the pain subset of the Foot Function Index (FFI). There was a significant reduction in the mean pain scores for all participants in all constructs of the FFI. Total FFI score was also significant ( P = .003). CAD-CAM orthoses have the potential to become a treatment modality of choice in CPHP since they have resulted in a significant improvement in heel pain after only 6 weeks' use. Therapeutic, Level IV: Prospective, comparative trial.

  16. Effect of resin coating and occlusal loading on microleakage of Class II computer-aided design/computer-aided manufacturing fabricated ceramic restorations: a confocal microscopic study.

    Science.gov (United States)

    Kitayama, Shuzo; Nasser, Nasser A; Pilecki, Peter; Wilson, Ron F; Nikaido, Toru; Tagami, Junji; Watson, Timothy F; Foxton, Richard M

    2011-05-01

    To evaluate the effect of resin coating and occlusal loading on microleakage of class II computer-aided design/computer-aided manufacturing (CAD/CAM) ceramic restorations. Molars were prepared for an mesio-occlusal-distal (MOD) inlay and were divided into two groups: non-coated (controls); and resin-coated, in which the cavity was coated with a combination of a dentin bonding system (Clearfil Protect Bond) and a flowable resin composite (Clearfil Majesty Flow). Ceramic inlays were fabricated using the CAD/CAM technique (CEREC 3) and cemented with resin cement (Clearfil Esthetic Cement). After 24 h of water storage, the restored teeth in each group were divided into two subgroups: unloaded or loaded with an axial force of 80 N at a rate of 2.5 cycles/s for 250,000 cycles while stored in water. After immersion in 0.25% Rhodamine B solution, the teeth were sectioned bucco-lingually at the mesial and distal boxes. Tandem scanning confocal microscopy (TSM) was used for evaluation of microleakage. The locations of the measurements were assigned to the cavity walls and floor. Loading did not have a significant effect on microleakage in either the resin-coated or non-coated group. Resin coating significantly reduced microleakage regardless of loading. The cavity floor exhibited greater microleakage compared to the cavity wall. TSM observation also revealed that microleakage at the enamel surface was minimal regardless of resin coating. In contrast, non-coated dentin showed extensive leakage, whereas resin-coated dentin showed decreased leakage. Resin coating with a combination of a dentin-bonding system and a flowable resin composite may be indicated prior to impression-taking when restoring teeth with CAD/CAM ceramic inlays in order to reduce microleakage at the tooth-resin interface.

  17. [Influence of coping material selection and porcelain firing on marginal and internal fit of computer-aided design/computer- aided manufacturing of zirconia and titanium ceramic implant-supported crowns].

    Science.gov (United States)

    Cuiling, Liu; Liyuan, Yang; Xu, Gao; Hong, Shang

    2016-06-01

    This study aimed to investigate the influence of coping material and porcelain firing on the marginal and internal fit of computer-aided design/computer-aided manufacturing (CAD/CAM) of zirconia ceramic implant- and titanium ceramic implant-supported crowns. Zirconia ceramic implant (group A, n = 8) and titanium metal ceramic implant-supported crowns (group B, n = 8) were produced from copings using the CAD/CAM system. The marginal and internal gaps of the copings and crowns were measured by using a light-body silicone replica technique combined with micro-computed tomography scanning to obtain a three-dimensional image. Marginal gap (MG), horizontal marginal discrepancy (HMD), and axial wall (AW) were measured. Statistical analyses were performed using SPSS 17.0. Prior to porcelain firing, the measurements for MG, HMD, and AW of copings in group A were significantly larger than those in group B (P 0.05). Porcelain firing significantly reduced MG (P 0.05). The marginal fits of CAD/CAM zirconia ceramic implant-supported crowns were superior to those of CAD/CAM titanium ceramic-supported crowns. The fits of both the CAD/CAM zirconia ceramic implant- and titanium ceramic implant-supported crowns were obviously influenced by porcelain firing.

  18. Intelligent Support for a Computer Aided Design Optimisation Cycle

    OpenAIRE

    B. Dolšak; M. Novak; J. Kaljun

    2006-01-01

    It is becoming more and more evident that  adding intelligence  to existing computer aids, such as computer aided design systems, can lead to significant improvements in the effective and reliable performance of various engineering tasks, including design optimisation. This paper presents three different intelligent modules to be applied within a computer aided design optimisation cycle to enable more intelligent and less experience-dependent design performance. 

  19. Specific features of organizng the computer-aided design of radio-electronic equipment for electrophysical facilities

    International Nuclear Information System (INIS)

    Mozin, I.V.; Vasil'ev, M.P.

    1985-01-01

    Problems of developing systems for computer-aided design (CAD) of radioelectronic equipment for large electrophysical facilities such as charged particle accelerators of new generation are discussed. The PLATA subsystem representing a part of CAD and used for printed circuit design is described. The subsystem PLATA is utilized to design, on the average, up to 150 types of circuits a year, 100-120 of which belong to circuits of increased complexity. In this case labour productivity of a designer at documentation increases almost two times

  20. Interstitial lung disease associated with collagen vascular disorders: disease quantification using a computer-aided diagnosis tool

    International Nuclear Information System (INIS)

    Marten, K.; Engelke, C.; Dicken, V.; Kneitz, C.; Hoehmann, M.; Kenn, W.; Hahn, D.

    2009-01-01

    The purpose of this study was to evaluate a computer-aided diagnosis (CAD) tool compared to human observers in quantification of interstitial lung disease (ILD) in patients with collagen-vascular disorders. A total of 52 patients with rheumatoid arthritis (n=24), scleroderma (n=14) and systemic lupus erythematosus (n=14) underwent thin-section CT. Two independent observers assessed the extent of ILD (EoILD), reticulation (EoRet) and ground-glass opacity (EoGGO). CAD assessed EoILD twice. Pulmonary function tests were obtained. Statistical evaluation used 95% limits of agreement and linear regression analysis. CAD correlated well with diffusing capacity (DL CO ) (R=-0.531, P CO (R=-0.705, P CO and moderately with FVC (DL CO : R=-0.663; FVC: R=-0.436; P≤0.005). The CAD system is a promising tool for ILD quantification, showing close correlation with human observers and physiologic impairment. (orig.)

  1. The Z-cad dual fluorescent sensor detects dynamic changes between the epithelial and mesenchymal cellular states.

    Science.gov (United States)

    Toneff, M J; Sreekumar, A; Tinnirello, A; Hollander, P Den; Habib, S; Li, S; Ellis, M J; Xin, L; Mani, S A; Rosen, J M

    2016-06-17

    The epithelial to mesenchymal transition (EMT) has been implicated in metastasis and therapy resistance of carcinomas and can endow cancer cells with cancer stem cell (CSC) properties. The ability to detect cancer cells that are undergoing or have completed EMT has typically relied on the expression of cell surface antigens that correlate with an EMT/CSC phenotype. Alternatively these cells may be permanently marked through Cre-mediated recombination or through immunostaining of fixed cells. The EMT process is dynamic, and these existing methods cannot reveal such changes within live cells. The development of fluorescent sensors that mirror the dynamic EMT state by following the expression of bona fide EMT regulators in live cells would provide a valuable new tool for characterizing EMT. In addition, these sensors will allow direct observation of cellular plasticity with respect to the epithelial/mesenchymal state to enable more effective studies of EMT in cancer and development. We generated a lentiviral-based, dual fluorescent reporter system, designated as the Z-cad dual sensor, comprising destabilized green fluorescent protein containing the ZEB1 3' UTR and red fluorescent protein driven by the E-cadherin (CDH1) promoter. Using this sensor, we robustly detected EMT and mesenchymal to epithelial transition (MET) in breast cancer cells by flow cytometry and fluorescence microscopy. Importantly, we observed dynamic changes in cellular populations undergoing MET. Additionally, we used the Z-cad sensor to identify and isolate minor subpopulations of cells displaying mesenchymal properties within a population comprising predominately epithelial-like cells. The Z-cad dual sensor identified cells with CSC-like properties more effectively than either the ZEB1 3' UTR or E-cadherin sensor alone. The Z-cad dual sensor effectively reports the activities of two factors critical in determining the epithelial/mesenchymal state of carcinoma cells. The ability of this stably

  2. Computer-aided diagnosis of pulmonary diseases using x-ray darkfield radiography

    DEFF Research Database (Denmark)

    Einarsdottir, Hildur; Yaroshenko, Andre; Velroyen, Astrid

    2015-01-01

    In this work we develop a computer-aided diagnosis (CAD) scheme for classification of pulmonary disease for grating-based x-ray radiography. In addition to conventional transmission radiography, the grating-based technique provides a dark-field imaging modality, which utilizes the scattering...... properties of the x-rays. This modality has shown great potential for diagnosing early stage emphysema and fibrosis in mouse lungs in vivo. The CAD scheme is developed to assist radiologists and other medical experts to develop new diagnostic methods when evaluating grating-based images. The scheme consists...... of three stages: (i) automatic lung segmentation; (ii) feature extraction from lung shape and dark-field image intensities; (iii) classification between healthy, emphysema and fibrosis lungs. A study of 102 mice was conducted with 34 healthy, 52 emphysema and 16 fibrosis subjects. Each image was manually...

  3. The future of computer-aided design and engineering at CERN

    CERN Document Server

    Høimyr, Nils-Joar

    2004-01-01

    This working note discusses design and engineering processes at CERN and Computer Aided Design and Engineering tools. The main focus of this note is Mechanical design and CAE activities and how to share and organize the data produced by CAD/CAE tools. These issues cannot be addressed without taking a global view of the engineering activities at CERN. As more and more of the detailed design work is done by external suppliers, the design processes at CERN change. Traditional design work where draftsmen are producing drawings on the request from engineers is replaced by conceptual design work done by domain specialists and engineers. Furthermore CAD and FEM tools have evolved from specialist tools to mainstream utilities mastered by most engineers. Design activities nowadays can now be carried out directly by the project engineer without the use of a design (drawing) office. This environment poses different requirements for design- and engineering support activities as well as the selection of CAE-tools. Design ...

  4. Development and application of computer-aided design methods for cell factory optimization

    DEFF Research Database (Denmark)

    Cardoso, Joao

    Genetically modified organisms (GMOs) can be used to produce chemicals for everyday applications. Engineering microorganisms is a multidisciplinary task comprising four steps: design, build, test and learn. The design and learn phases rely on computational, statistical models, data analysis...... and machine learning. The process of creating strains with commercially relevant titers is time consuming and expensive. Computer-aided design (CAD) software can help scientists build better strains by providing models and algorithms that can be used to generate and test hypotheses before implementing them...... microbial cell factories. In this PhD thesis we present cameo, a CAD software for metabolic engineering that uses GEMs. State-of-the-art and novel algorithms are implemented in cameo. These algorithms have been made accessible using a high-level API to enable any user to start running them without having...

  5. Identification of a putative man-made object from an underwater crash site using CAD model superimposition.

    Science.gov (United States)

    Vincelli, Jay; Calakli, Fatih; Stone, Michael; Forrester, Graham; Mellon, Timothy; Jarrell, John

    2018-04-01

    In order to identify an object in video, a comparison with an exemplar object is typically needed. In this paper, we discuss the methodology used to identify an object detected in underwater video that was recorded during an investigation into Amelia Earhart's purported crash site. A computer aided design (CAD) model of the suspected aircraft component was created based on measurements made from orthogonally rectified images of a reference aircraft, and validated against historical photographs of the subject aircraft prior to the crash. The CAD model was then superimposed on the underwater video, and specific features on the object were geometrically compared between the CAD model and the video. This geometrical comparison was used to assess the goodness of fit between the purported object and the object identified in the underwater video. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Anniversary Paper: History and status of CAD and quantitative image analysis: The role of Medical Physics and AAPM

    International Nuclear Information System (INIS)

    Giger, Maryellen L.; Chan, Heang-Ping; Boone, John

    2008-01-01

    The roles of physicists in medical imaging have expanded over the years, from the study of imaging systems (sources and detectors) and dose to the assessment of image quality and perception, the development of image processing techniques, and the development of image analysis methods to assist in detection and diagnosis. The latter is a natural extension of medical physicists' goals in developing imaging techniques to help physicians acquire diagnostic information and improve clinical decisions. Studies indicate that radiologists do not detect all abnormalities on images that are visible on retrospective review, and they do not always correctly characterize abnormalities that are found. Since the 1950s, the potential use of computers had been considered for analysis of radiographic abnormalities. In the mid-1980s, however, medical physicists and radiologists began major research efforts for computer-aided detection or computer-aided diagnosis (CAD), that is, using the computer output as an aid to radiologists--as opposed to a completely automatic computer interpretation--focusing initially on methods for the detection of lesions on chest radiographs and mammograms. Since then, extensive investigations of computerized image analysis for detection or diagnosis of abnormalities in a variety of 2D and 3D medical images have been conducted. The growth of CAD over the past 20 years has been tremendous--from the early days of time-consuming film digitization and CPU-intensive computations on a limited number of cases to its current status in which developed CAD approaches are evaluated rigorously on large clinically relevant databases. CAD research by medical physicists includes many aspects--collecting relevant normal and pathological cases; developing computer algorithms appropriate for the medical interpretation task including those for segmentation, feature extraction, and classifier design; developing methodology for assessing CAD performance; validating the

  7. Computer aided diagnosis and localization of lateralized temporal lobe epilepsy using interictal FDG-PET

    Directory of Open Access Journals (Sweden)

    Wesley Thomas Kerr

    2013-04-01

    Full Text Available Interictal FDG-PET (iPET is a core tool for localizing the epileptogenic focus, potentially before structural MRI, that does not require rare and transient epileptiform discharges or seizures on EEG. The visual interpretation of iPET is challenging and requires years of epilepsy-specific expertise. We have developed an automated computer-aided diagnostic (CAD tool that has the potential to work both independent of and synergistically with expert analysis. Our tool operates on distributed metabolic changes across the whole brain measured by iPET to both diagnose and lateralize temporal lobe epilepsy. When diagnosing left temporal lobe epilepsy (LTLE or right TLE (RTLE versus non-epileptic seizures (NES, our accuracy in reproducing the results of the gold standard long term video-EEG monitoring was 82% (95% confidence interval [CI] 69-90% or 88% (95% CI 76-94%, respectively. The classifier that both diagnosed and lateralized the disease had overall accuracy of 76% (95% CI 66-84%, where 89% (95% CI 77-96% of patients correctly identified with epilepsy were correctly lateralized. When identifying LTLE, our CAD tool utilized metabolic changes across the entire brain. By contrast, only temporal regions and the right frontal lobe cortex, were needed to identify RTLE accurately, a finding consistent with clinical observations and indicative of a potential pathophysiological difference between RTLE and LTLE. The goal of CADs is to complement—not replace—expert analysis. In our dataset, the accuracy of manual analysis of iPET (~80% was similar to CAD. The square correlation between our CAD tool and manual analysis, however, was only 30%, indicating that our CAD tool does not recreate manual analysis. The addition of clinical information to our CAD, however, did not substantively change performance. These results suggest that automated analysis might provide clinically valuable information to focus treatment more effectively.

  8. TGeoCad: an Interface between ROOT and CAD Systems

    International Nuclear Information System (INIS)

    Luzzi, C; Carminati, F

    2014-01-01

    In the simulation of High Energy Physics experiment a very high precision in the description of the detector geometry is essential to achieve the required performances. The physicists in charge of Monte Carlo Simulation of the detector need to collaborate efficiently with the engineers working at the mechanical design of the detector. Often, this collaboration is made hard by the usage of different and incompatible software. ROOT is an object-oriented C++ framework used by physicists for storing, analyzing and simulating data produced by the high-energy physics experiments while CAD (Computer-Aided Design) software is used for mechanical design in the engineering field. The necessity to improve the level of communication between physicists and engineers led to the implementation of an interface between the ROOT geometrical modeler used by the virtual Monte Carlo simulation software and the CAD systems. In this paper we describe the design and implementation of the TGeoCad Interface that has been developed to enable the use of ROOT geometrical models in several CAD systems. To achieve this goal, the ROOT geometry description is converted into STEP file format (ISO 10303), which can be imported and used by many CAD systems

  9. TGeoCad: an Interface between ROOT and CAD Systems

    Science.gov (United States)

    Luzzi, C.; Carminati, F.

    2014-06-01

    In the simulation of High Energy Physics experiment a very high precision in the description of the detector geometry is essential to achieve the required performances. The physicists in charge of Monte Carlo Simulation of the detector need to collaborate efficiently with the engineers working at the mechanical design of the detector. Often, this collaboration is made hard by the usage of different and incompatible software. ROOT is an object-oriented C++ framework used by physicists for storing, analyzing and simulating data produced by the high-energy physics experiments while CAD (Computer-Aided Design) software is used for mechanical design in the engineering field. The necessity to improve the level of communication between physicists and engineers led to the implementation of an interface between the ROOT geometrical modeler used by the virtual Monte Carlo simulation software and the CAD systems. In this paper we describe the design and implementation of the TGeoCad Interface that has been developed to enable the use of ROOT geometrical models in several CAD systems. To achieve this goal, the ROOT geometry description is converted into STEP file format (ISO 10303), which can be imported and used by many CAD systems.

  10. CAD/CAM: improved design quality, increased productivity

    Energy Technology Data Exchange (ETDEWEB)

    Evans, D. E.; England, J.

    1980-01-01

    Maintaining productivity levels while assuring the quality of engineering products grows increasingly more difficult and costly for industries such as the energy industry which are heavily committed to product design. The man/machine interface made possible through the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology can be applied to the design process as a tool for increased control to assure the quality of the final engineering product. The quality-control aspects of CAD/CAM technology are addressed in this presentation.

  11. Computer-aided assessment in statistics: the CAMPUS project

    Directory of Open Access Journals (Sweden)

    Neville Hunt

    1998-12-01

    Full Text Available The relentless drive for 'efficiency' in higher education, and the consequent increase in workloads, has given university teachers a compelling incentive to investigate alternative forms of assessment. Some forms of assessment with a clear educational value can no longer be entertained because of the burden placed on the teacher. An added concern is plagiarism, which anecdotal evidence would suggest is on the increase yet which is difficult to detect in large modules with more than one assessor. While computer-aided assessment (CAA has an enthusiastic following, it is not clear to many teachers that it either reduces workloads or reduces the risk of cheating. In an ideal world, most teachers would prefer to give individual attention and personal feedback to each student when marking their work. In this sense CAA must be seen as second best and will therefore be used only if it is seen to offer significant benefits in terms of reduced workloads or increased validity.

  12. Computer Aided Design of a Low-Cost Painting Robot

    Directory of Open Access Journals (Sweden)

    SYEDA MARIA KHATOON ZAIDI

    2017-10-01

    Full Text Available The application of robots or robotic systems for painting parts is becoming increasingly conventional; to improve reliability, productivity, consistency and to decrease waste. However, in Pakistan only highend Industries are able to afford the luxury of a robotic system for various purposes. In this study we propose an economical Painting Robot that a small-scale industry can install in their plant with ease. The importance of this robot is that being cost effective, it can easily be replaced in small manufacturing industries and therefore, eliminate health problems occurring to the individual in charge of painting parts on an everyday basis. To achieve this aim, the robot is made with local parts with only few exceptions, to cut costs; and the programming language is kept at a mediocre level. Image processing is used to establish object recognition and it can be programmed to paint various simple geometries. The robot is placed on a conveyer belt to maximize productivity. A four DoF (Degree of Freedom arm increases the working envelope and accessibility of painting different shaped parts with ease. This robot is capable of painting up, front, back, left and right sides of the part with a single colour. Initially CAD (Computer Aided Design models of the robot were developed which were analyzed, modified and improved to withstand loading condition and perform its task efficiently. After design selection, appropriate motors and materials were selected and the robot was developed. Throughout the development phase, minor problems and errors were fixed accordingly as they arose. Lastly the robot was integrated with the computer and image processing for autonomous control. The final results demonstrated that the robot is economical and reduces paint wastage.

  13. Computer aided design of a low-cost painting robot

    International Nuclear Information System (INIS)

    Zaidi, S.M.; Janejo, F.; Mujtaba, S.B.

    2017-01-01

    The application of robots or robotic systems for painting parts is becoming increasingly conventional; to improve reliability, productivity, consistency and to decrease waste. However, in Pakistan only highend Industries are able to afford the luxury of a robotic system for various purposes. In this study we propose an economical Painting Robot that a small-scale industry can install in their plant with ease. The importance of this robot is that being cost effective, it can easily be replaced in small manufacturing industries and therefore, eliminate health problems occurring to the individual in charge of painting parts on an everyday basis. To achieve this aim, the robot is made with local parts with only few exceptions, to cut costs; and the programming language is kept at a mediocre level. Image processing is used to establish object recognition and it can be programmed to paint various simple geometries. The robot is placed on a conveyer belt to maximize productivity. A four DoF (Degree of Freedom) arm increases the working envelope and accessibility of painting different shaped parts with ease. This robot is capable of painting up, front, back, left and right sides of the part with a single colour. Initially CAD (Computer Aided Design) models of the robot were developed which were analyzed, modified and improved to withstand loading condition and perform its task efficiently. After design selection, appropriate motors and materials were selected and the robot was developed. Throughout the development phase, minor problems and errors were fixed accordingly as they arose. Lastly the robot was integrated with the computer and image processing for autonomous control. The final results demonstrated that the robot is economical and reduces paint wastage. (author)

  14. Automatic computer aided analysis algorithms and system for adrenal tumors on CT images.

    Science.gov (United States)

    Chai, Hanchao; Guo, Yi; Wang, Yuanyuan; Zhou, Guohui

    2017-12-04

    The adrenal tumor will disturb the secreting function of adrenocortical cells, leading to many diseases. Different kinds of adrenal tumors require different therapeutic schedules. In the practical diagnosis, it highly relies on the doctor's experience to judge the tumor type by reading the hundreds of CT images. This paper proposed an automatic computer aided analysis method for adrenal tumors detection and classification. It consisted of the automatic segmentation algorithms, the feature extraction and the classification algorithms. These algorithms were then integrated into a system and conducted on the graphic interface by using MATLAB Graphic user interface (GUI). The accuracy of the automatic computer aided segmentation and classification reached 90% on 436 CT images. The experiments proved the stability and reliability of this automatic computer aided analytic system.

  15. WEBSITE EXECUTION OF CAD MODULES

    Directory of Open Access Journals (Sweden)

    A. A. Lyalinsky

    2013-01-01

    Full Text Available Web-based interface of modules that are part of the computer-aided design system in microelectronics is considered. The influence of several factors (available computer  memory, maximum allowed run time, degree of homogeneity of the software on the structure of the created system is investigated. Synchronous and asynchronous variants of interaction between control and executive parts are described. References on the systems that allow an access to applications in CAD microelectronics and are based on the principles discussed in this article are given.

  16. Intelligent computer-aided training and tutoring

    Science.gov (United States)

    Loftin, R. Bowen; Savely, Robert T.

    1991-01-01

    Specific autonomous training systems based on artificial intelligence technology for use by NASA astronauts, flight controllers, and ground-based support personnel that demonstrate an alternative to current training systems are described. In addition to these specific systems, the evolution of a general architecture for autonomous intelligent training systems that integrates many of the features of traditional training programs with artificial intelligence techniques is presented. These Intelligent Computer-Aided Training (ICAT) systems would provide, for the trainee, much of the same experience that could be gained from the best on-the-job training. By integrating domain expertise with a knowledge of appropriate training methods, an ICAT session should duplicate, as closely as possible, the trainee undergoing on-the-job training in the task environment, benefitting from the full attention of a task expert who is also an expert trainer. Thus, the philosophy of the ICAT system is to emulate the behavior of an experienced individual devoting his full time and attention to the training of a novice - proposing challenging training scenarios, monitoring and evaluating the actions of the trainee, providing meaningful comments in response to trainee errors, responding to trainee requests for information, giving hints (if appropriate), and remembering the strengths and weaknesses displayed by the trainee so that appropriate future exercises can be designed.

  17. Computer-Aided Parallelizer and Optimizer

    Science.gov (United States)

    Jin, Haoqiang

    2011-01-01

    The Computer-Aided Parallelizer and Optimizer (CAPO) automates the insertion of compiler directives (see figure) to facilitate parallel processing on Shared Memory Parallel (SMP) machines. While CAPO currently is integrated seamlessly into CAPTools (developed at the University of Greenwich, now marketed as ParaWise), CAPO was independently developed at Ames Research Center as one of the components for the Legacy Code Modernization (LCM) project. The current version takes serial FORTRAN programs, performs interprocedural data dependence analysis, and generates OpenMP directives. Due to the widely supported OpenMP standard, the generated OpenMP codes have the potential to run on a wide range of SMP machines. CAPO relies on accurate interprocedural data dependence information currently provided by CAPTools. Compiler directives are generated through identification of parallel loops in the outermost level, construction of parallel regions around parallel loops and optimization of parallel regions, and insertion of directives with automatic identification of private, reduction, induction, and shared variables. Attempts also have been made to identify potential pipeline parallelism (implemented with point-to-point synchronization). Although directives are generated automatically, user interaction with the tool is still important for producing good parallel codes. A comprehensive graphical user interface is included for users to interact with the parallelization process.

  18. Computer-aided reduction of plasma data

    International Nuclear Information System (INIS)

    Shariati, S.

    1984-01-01

    Poor signal-to-noise ratios and the non-linear characteristics of the data obtained by most plasma diagnostic equipment makes computer-aided data handling a desirable feature in plasma laboratories. The Lecroy 3500-SA32 signal analyzer is used as the data handling system in this work. The performance of the Lecroy 3500-SA32 signal analyzer, used for recording and reducing the plasma data under the noisy environment of the laboratory, is reported. The data characteristics and software programs are discussed for three types of plasma diagnostic equipment: 1) Langmuir Probes; 2) Charge Exchange Neutral Energy Analyzers; 3) Retarding Potential Energy Analyzers. In order to protect the computer internal circuitry and to have satisfactory data acquisition and handling, methods for dealing with the noisy environment, including stray magnetic fields, RF radiation, and transient spikes on power lines, are also developed. Three computer programs are included which obtain an iterated best fit of experimental data to the corresponding analytical expressions for each case. The new data handling system enables the user to do a real-time analysis of data by using the interactive features of the Lecroy 3500-SA32 system

  19. A computer-aided continuous assessment system

    Directory of Open Access Journals (Sweden)

    B. C.H. Turton

    1996-12-01

    Full Text Available Universities within the United Kingdom have had to cope with a massive expansion in undergraduate student numbers over the last five years (Committee of Scottish University Principals, 1993; CVCP Briefing Note, 1994. In addition, there has been a move towards modularization and a closer monitoring of a student's progress throughout the year. Since the price/performance ratio of computer systems has continued to improve, Computer- Assisted Learning (CAL has become an attractive option. (Fry, 1990; Benford et al, 1994; Laurillard et al, 1994. To this end, the Universities Funding Council (UFQ has funded the Teaching and Learning Technology Programme (TLTP. However universities also have a duty to assess as well as to teach. This paper describes a Computer-Aided Assessment (CAA system capable of assisting in grading students and providing feedback. In this particular case, a continuously assessed course (Low-Level Languages of over 100 students is considered. Typically, three man-days are required to mark one assessed piece of coursework from the students in this class. Any feedback on how the questions were dealt with by the student are of necessity brief. Most of the feedback is provided in a tutorial session that covers the pitfalls encountered by the majority of the students.

  20. Computer aided materials design; Keisanki zairyo sekkei

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The questionnaire survey on the computer aided materials design (CAMD), and the survey of current domestic and overseas software concerned were carried out to clarify developmental issues. The current elementary technology of CAMD was also surveyed to study its several problems caused with a progress of material design technology due to drastic diffusion of CAMD. This project aims at establishment of a new demanded software, computer chemistry, focusing attention on functional materials such as catalyst, polymer and non-linear electronic materials. Microscopic simulation technology was mainly surveyed in fiscal 1996. Although some fruitful results have been obtained in the fields of medical and agricultural chemicals, organic compounds, proteins, catalysts and electronic materials, such some problems are pointed out as `CAMD cannot handle an actual size of the target system` and `commercially available software are very expensive.` Reliable tool development as elementary technology, and the verification of its applications are thus required. Meso-dynamics, polymers, surface reaction and integrated technological environment attract users` attention. 27 refs., 16 figs., 2 tabs.

  1. Computer aided probabilistic assessment of containment integrity

    International Nuclear Information System (INIS)

    Tsai, J.C.; Touchton, R.A.

    1984-01-01

    In the probabilistic risk assessment (PRA) of a nuclear power plant, there are three probability-based techniques which are widely used for event sequence frequency quantification (including nodal probability estimation). These three techniques are the event tree analysis, the fault tree analysis and the Bayesian approach for database development. In the barrier analysis for assessing radionuclide release to the environment in a PRA study, these techniques are employed to a greater extent in estimating conditions which could lead to failure of the fuel cladding and the reactor coolant system (RCS) pressure boundary, but to a lesser degree in the containment pressure boundary failure analysis. The main reason is that containment issues are currently still in a state of flux. In this paper, the authors describe briefly the computer programs currently used by the nuclear industry to do event tree analyses, fault tree analyses and the Bayesian update. The authors discuss how these computer aided probabilistic techniques might be adopted for failure analysis of the containment pressure boundary

  2. Geometric modeling for computer aided design

    Science.gov (United States)

    Schwing, James L.; Olariu, Stephen

    1995-01-01

    The primary goal of this grant has been the design and implementation of software to be used in the conceptual design of aerospace vehicles particularly focused on the elements of geometric design, graphical user interfaces, and the interaction of the multitude of software typically used in this engineering environment. This has resulted in the development of several analysis packages and design studies. These include two major software systems currently used in the conceptual level design of aerospace vehicles. These tools are SMART, the Solid Modeling Aerospace Research Tool, and EASIE, the Environment for Software Integration and Execution. Additional software tools were designed and implemented to address the needs of the engineer working in the conceptual design environment. SMART provides conceptual designers with a rapid prototyping capability and several engineering analysis capabilities. In addition, SMART has a carefully engineered user interface that makes it easy to learn and use. Finally, a number of specialty characteristics have been built into SMART which allow it to be used efficiently as a front end geometry processor for other analysis packages. EASIE provides a set of interactive utilities that simplify the task of building and executing computer aided design systems consisting of diverse, stand-alone, analysis codes. Resulting in a streamlining of the exchange of data between programs reducing errors and improving the efficiency. EASIE provides both a methodology and a collection of software tools to ease the task of coordinating engineering design and analysis codes.

  3. Computer aided information system for a PWR

    International Nuclear Information System (INIS)

    Vaidian, T.A.; Karmakar, G.; Rajagopal, R.; Shankar, V.; Patil, R.K.

    1994-01-01

    The computer aided information system (CAIS) is designed with a view to improve the performance of the operator. CAIS assists the plant operator in an advisory and support role, thereby reducing the workload level and potential human errors. The CAIS as explained here has been designed for a PWR type KLT- 40 used in Floating Nuclear Power Stations (FNPS). However the underlying philosophy evolved in designing the CAIS can be suitably adopted for other type of nuclear power plants too (BWR, PHWR). Operator information is divided into three broad categories: a) continuously available information b) automatically available information and c) on demand information. Two in number touch screens are provided on the main control panel. One is earmarked for continuously available information and the other is dedicated for automatically available information. Both the screens can be used at the operator's discretion for on-demand information. Automatically available information screen overrides the on-demand information screens. In addition to the above, CAIS has the features of event sequence recording, disturbance recording and information documentation. CAIS design ensures that the operator is not overburdened with excess and unnecessary information, but at the same time adequate and well formatted information is available. (author). 5 refs., 4 figs

  4. Computer-Aided Video Differential Planimetry

    Science.gov (United States)

    Tobin, Michael; Djoleto, Ben D.

    1984-08-01

    THE VIDEO DIFFERENTIAL PLANIMETER (VDP)1 is a re-mote sensing instrument that can measure minute changes in the area of any object seen by an optical scanning system. The composite video waveforms obtained by scanning the object against a contrasting back-ground are amplified and shaped to yield a sequence of constant amplitude pulses whose polarity distinguishes the studied area from its background and whose varying widths reflect the dynamics of the viewed object. These pulses are passed through a relatively long time-constant capacitor-resistor circuit and are then fed into an integrator. The net integration voltage resulting from the most recent sequence of object-background time pulses is recorded and the integrator is returned to zero at the end of each video frame. If the object's area remains constant throughout the following frame, the integrator's summation will also remain constant. However, if the object's area varies, the positive and negative time pulses entering the integrator will change, and the integrator's summation will vary proportionately. The addition of a computer interface and a video recorder enhances the versatility and the resolving power of the VDP by permitting the repeated study and analysis of selected portions of the recorded data, thereby uncovering the major sources of the object's dynamics. Among the medical and biological procedures for which COMPUTER-AIDED VIDEO DIFFERENTIAL PLANIMETRY is suitable are Ophthalmoscopy, Endoscopy, Microscopy, Plethysmography, etc. A recent research study in Ophthalmoscopy2 will be cited to suggest a useful application of Video Differential Planimetry.

  5. Effects of Computer-Aided Manufacturing Technology on Precision of Clinical Metal-Free Restorations

    Directory of Open Access Journals (Sweden)

    Ki-Hong Lee

    2015-01-01

    Full Text Available Purpose. The purpose of this study was to investigate the marginal fit of metal-free crowns made by three different computer-aided design/computer-aided manufacturing (CAD/CAM systems. Materials and Methods. The maxillary left first premolar of a dentiform was prepared for all-ceramic crown restoration. Thirty all-ceramic premolar crowns were made, ten each manufactured by the Lava system, Cercon, and Cerec. Ten metal ceramic gold (MCG crowns served as control. The marginal gap of each sample was measured under a stereoscopic microscope at 75x magnification after cementation. One-way ANOVA and the Duncan’s post hoc test were used for data analysis at the significance level of 0.05. Results. The mean (standard deviation marginal gaps were 70.5 (34.4 μm for the MCG crowns, 87.2 (22.8 μm for Lava, 58.5 (17.6 μm for Cercon, and 72.3 (30.8 μm for Cerec. There were no significant differences in the marginal fit among the groups except that the Cercon crowns had significantly smaller marginal gaps than the Lava crowns (P<0.001.  Conclusions. Within the limitation of this study, all the metal-free restorations made by the digital CAD/CAM systems had clinically acceptable marginal accuracy.

  6. Effects of Computer-Aided Manufacturing Technology on Precision of Clinical Metal-Free Restorations.

    Science.gov (United States)

    Lee, Ki-Hong; Yeo, In-Sung; Wu, Benjamin M; Yang, Jae-Ho; Han, Jung-Suk; Kim, Sung-Hun; Yi, Yang-Jin; Kwon, Taek-Ka

    2015-01-01

    The purpose of this study was to investigate the marginal fit of metal-free crowns made by three different computer-aided design/computer-aided manufacturing (CAD/CAM) systems. The maxillary left first premolar of a dentiform was prepared for all-ceramic crown restoration. Thirty all-ceramic premolar crowns were made, ten each manufactured by the Lava system, Cercon, and Cerec. Ten metal ceramic gold (MCG) crowns served as control. The marginal gap of each sample was measured under a stereoscopic microscope at 75x magnification after cementation. One-way ANOVA and the Duncan's post hoc test were used for data analysis at the significance level of 0.05. The mean (standard deviation) marginal gaps were 70.5 (34.4) μm for the MCG crowns, 87.2 (22.8) μm for Lava, 58.5 (17.6) μm for Cercon, and 72.3 (30.8) μm for Cerec. There were no significant differences in the marginal fit among the groups except that the Cercon crowns had significantly smaller marginal gaps than the Lava crowns (P < 0.001). Within the limitation of this study, all the metal-free restorations made by the digital CAD/CAM systems had clinically acceptable marginal accuracy.