Peer-reviewed journal papers

[2023]

• Luo G, Liu T, Lu J, Chen X, Yu L, Wu J, Chen D, Cai W*. Influence of Data Distribution on Federated Learning Performance in Tumor Segmentation. Radiology: Artificial Intelligence, 2023 Apr 26;5(3):e220082, PMID: 37293342
• Madhani A, King S, Zhu J, Karmali F, Welling D, Cai W, Jordan J, Lewis R. Vestibular dysfunction in neurofibromatosis type 2–related schwannomatosis. Brain Commun. 2023 Mar; 5(2): fcad089. PMID: 37025569
• Liu Y, Li J, Wang Y, Cai W, Chen F, Liu W, Mao X, Gan K, Wang R, Sun D, Qiu H, Liu B. CT and MRI fusion based on generative adversarial network and convolutional neural networks under image enhancement. Journal of Biomedical Engineering 2023 Apr 25;40(2):208-216. PMID: 37139750
• Zhang K, Luo G, Li W, Zhu Y, Pan J, Li X, Liu C, Liang J, Zhan Y, Zheng J, Li S, Cai W*, Hong G*. Automatic Image Segmentation and Grading Diagnosis of Sacroiliitis Associated with AS Using a Deep Convolutional Neural Network on CT Images. Journal of Digital Imaging, 2023 June, PMID: 37268841
• Luo G, Liu T, Lu J, Chen X, Yu L, Wu J, Chen D, Cai W*. Influence of Data Distribution on Federated Learning Performance in Tumor Segmentation. Radiology: Artificial Intelligence, 2023 Apr 26;5(3):e220082, PMID: 37293342

[2022]

• Wu X, Tan G, Pu B, Duan M, Cai W*. DH-GAC: deep hierarchical context fusion network with modified geodesic active contour for multiple neurofibromatosis segmentation. Neural Computing and Applications 34 (22), 2022
• Ly KI, Merker V, Cai W, Bredella M, Muzikansky A, Thalheimer RD, Da JL, Orr CC, Herr HP, Morris ME, Chang CY, Harris GJ, Plotkin SR, Jordan JT. Ten-Year Follow-up of Internal Neurofibroma Growth Behavior in Adult Patients With Neurofibromatosis Type 1 Using Whole- Body MRI. Neurology. 2023 Feb 14;100(7):e661-e670. PMID: 36332985
• Fury M, Liu T, Cai W, O'Donnell E, Oh L. Change in Humeral Anchor Position Significantly Affects Isometry in UCL Repair: A 3-Dimensional Computer Modeling Study. Journal of Shoulder and Elbow Surgery 2022 Nov; 31(11):2328-2338. PMID: 35798228
• Fisher M, Blakeley J, Weiss B, Dombi E, Ahlawat S, Akshintala S, Belzberg A, Bornhorst M, Bredella M, Cai W, Ferner R, Gross R, Harris G, Listernick R, Ly I, Martin S, Mautner V, Salamon J, Salerno K, Spinner R, Staedtke V, Ullrich N, Upadhyaya M, Wolters P, Yohay K, Widemann B. Management of Neurofibromatosis Type 1-Associated Plexiform Neurofibromas. Neuro-Oncology 24(11), 1827–1844, 2022 Jun. PMID: 35657359
• Zhang JW, Chen W, Ly KI, Zhang X, Yan F, Jordan J, Harris G, Plotkin S, Hao P, Cai W*. DINs: Deep Interactive Networks for Neurofibroma Segmentation in Neurofibromatosis Type 1 on Whole- Body MRI. IEEE J Biomed Health Inform. 2022 Feb;26(2):786-797. PMID: 34106871
• Shi Z, Cai W#, Feng X, Cai J, Liang Y, Xu J, Zhen J, Liang X. Radiomics Analysis of Gd-EOB- DTPA Enhanced Hepatic MRI for Assessment of Functional Liver Reserve, Academic Radiology, Academic Radiology. 2022 Feb;29(2):213-218. PMID: 34183230
• Li H, Shen J, Shou J, Han W, Gong L, Xu Y, Chen P, Wang K, Zhang S, Sun C, Zhang J, Niu Z, Pan H*, Cai W*, Fang Y*. Exploring the Interobserver Agreement in Computer-Aided Radiologic Tumor Measurement and Evaluation of Tumor Response. Frontiers in Oncology, 2022 Jan, 11:691638. PMID: 35174064

[2021]

• Wang Q, Li Z, Yang J, Peng S, Zhou Q, Yao K, Cai W, Xie Z, Qin F, Li H, Chen X, Li K, Huang H. Loss of NEIL3 Activates Radiotherapy Resistance in the Progression of Prostate Cancer. Cancer Biol Med. 2021 Oct. PMID: 34591415
• Rahmanuddin S, Korn R, Cridebring D, Borazanci E, Brase J, Boswell W, Jamil A, Cai W, Sabir A, Motarjem P, Koay E, Maitra A, Goel A, Ho J, Chung V, and Von Hoff D Role of 3D volumetric and perfusion imaging for detecting early changes in pancreatic adenocarcinoma. Frontier in Oncology. 2021 Sep 8;11:678617. PMID: 34568010
• Zhou Q, Li K, Lai Y, Yao K, Wang Q, Zhan X, Peng S, Cai W, Yao W, Zang X, Xu K, Huang J, Huang H. B7 score and T cell infiltration stratify immune status in prostate cancer. J Immunother Cancer. 2021 Aug;9(8):e002455. PMID: 34417325
• Liu T, Hong G, Cai W*. A Comparative Study of Effective Atomic Number Calculations for Dual- Energy CT. Medical Physics. 2021 Oct;48(10):5908-5923. PMID: 34390593
• Gu, L., Liang, J., Zhan, Y., Pan, J., Zhang, Y., Cai, W., and Hong, G., "Dual-Energy Computed Tomography Virtual Noncalcium Imaging for the Detection of Acute Bone Marrow Edema in Vertebrae: Qualitative and Quantitative Analysis," Journal of Medical Imaging and Health Informatics, 11(3), pp. 752-759, (2021). https://doi.org/10.1166/jmihi.2021.3363
• Shen, Q., Shan, Y., Xu, W., Hu, G., Chen, W., Feng, Z., Pang, P., Ding, Z., and Cai, W., "Risk stratification of thymic epithelial tumors by using a nomogram combined with radiomic features and TNM staging," European Radiology, 31(1), pp. 423-435, (2021). https://doi.org/10.1007/s00330-020-07100-4

[2020]

• Cai, W., Liu, T., Xue, X., Luo, G., Wang, X., Shen, Y., Fang, Q., Sheng, J., Chen, F., and Liang, T., "CT Quantification and Machine-learning Models for Assessment of Disease Severity and Prognosis of COVID-19 Patients," Academic radiology, 27(12), pp. 1665-1678, (2020). https://doi.org/10.1016/j.acra.2020.09.004
• Gao, Z., Tao, Y., Lai, Y., Wang, Q., Li, Z., Peng, S., Chen, J., Cai, W., Li, K., and Huang, H., "Immune Cytolytic Activity as an Indicator of Immune Checkpoint Inhibitors Treatment for Prostate Cancer," Frontiers in Bioengineering and Biotechnology, 8, p. 930, (2020). https://doi.org/10.3389/fbioe.2020.00930
• Li, K., Peng, S., Li, Z., Lai, Y., Wang, Q., Tao, Y., Wu, W., Zhou, Q., Gao, Z., Chen, J., Li, H., Cai, W., Guo, Z., and Huang, H., "Topoisomerase II-binding protein 1 promotes the progression of prostate cancer via ATR-CHK1 signaling pathway," Aging (Albany NY), 12(10), p. 9948, (2020). https://doi.org/10.18632/aging.103260
• Li, Y., Tan, G., Vangel, M., Hall, J., and Cai, W., "Influence of feature calculating parameters on the reproducibility of CT radiomic features: a thoracic phantom study," Quantitative Imaging in Medicine and Surgery, 10(9), p. 1775, (2020). https://doi.org/10.21037/qims-19-921
• Li, Z., Wang, Q., Peng, S., Yao, K., Chen, J., Tao, Y., Gao, Z., Wang, F., Li, H., and Cai, W., "The metastatic promoter DEPDC1B induces epithelial‐mesenchymal transition and promotes prostate cancer cell proliferation via Rac1‐PAK1 signaling," Clinical and translational medicine, 10(6), p. e191, (2020). https://doi.org/10.1002/ctm2.191
• Liu, Y., Jordan, J. T., Bredella, M. A., Erdin, S., Walker, J. A., Vangel, M., Harris, G. J., Plotkin, S. R., and Cai, W., "Correlation between NF1 genotype and imaging phenotype on whole-body MRI: NF1 radiogenomics," Neurology, 94(24), pp. e2521-e2531, (2020). https://doi.org/10.1212/wnl.0000000000009490
• Wu, X., Tan, G., Li, K., Li, S., Wen, H., Zhu, X., and Cai, W., "Deep Parametric Active Contour Model for Neurofibromatosis Segmentation," Future Generation Computer Systems, 112, pp. 58-66, (2020). https://doi.org/10.1016/j.future.2020.05.001
• Zhou, J., Lu, J., Gao, C., Zeng, J., Zhou, C., Lai, X., Cai, W., and Xu, M., "Predicting the response to neoadjuvant chemotherapy for breast cancer: wavelet transforming radiomics in MRI," BMC cancer, 20(1), p. 100, (2020). https://doi.org/10.1186/s12885-020-6523-2
• Zhou, Q., Li, K., Chen, X., He, H., Peng, S., Peng, S., Wang, Q., Li, Z. a., Tao, Y., and Cai, W., "HHLA2 and PD-L1 co-expression predicts poor prognosis in patients with clear cell renal cell carcinoma," Journal for immunotherapy of cancer, 8(1)(2020). https://doi.org/10.1136/jitc-2019-000157corr1

[2019 and Early]

• Li, Q., Yang, L., Duan, Y., Xiang, F., McCarthy, C. J., Thabet, A., Cai, W., Grajo, J. R., Baikpour, M., and McConnell, R., "A low-cost highly configurable phantom for simulation of imaging-guided endocavitary procedures," Ultrasound quarterly, 35(1), pp. 61-67, (2019). https://doi.org/10.1097/ruq.0000000000000413
• Cai, W. and Hong, G., "Quantitative image analysis for evaluation of tumor response in clinical oncology," Chronic diseases and translational medicine, 4(1), pp. 18-28, (2018). https://doi.org/10.1016/j.cdtm.2018.01.002
• Cai, W., Steinberg, S. M., Bredella, M. A., Basinsky, G., Somarouthu, B., Plotkin, S. R., Solomon, J., Widemann, B. C., Harris, G. J., and Dombi, E., "Volumetric MRI analysis of plexiform neurofibromas in neurofibromatosis type 1: comparison of two methods," Academic radiology, 25(2), pp. 144-152, (2018). https://doi.org/10.1016/j.acra.2017.09.004
• Jordan, J. T., Smith, M. J., Walker, J. A., Erdin, S., Talkowski, M. E., Merker, V. L., Ramesh, V., Cai, W., Harris, G. J., and Bredella, M. A., "Pain correlates with germline mutation in schwannomatosis," Medicine, 97(5)(2018). https://doi.org/10.1097/md.0000000000009717
• Li, W., Wang, Y., Liu, Y., Wu, T., Cai, W., Shuai, X., and Hong, G., "Preliminary study of MR and fluorescence dual-mode imaging: Combined macrophage-targeted and superparamagnetic polymeric micelles," International journal of medical sciences, 15(2), p. 129, (2018). https://doi.org/10.7150/ijms.21610
• Liu, Y., Cai, W., and Hong, G., "Automatic segmentation of shoulder joint in MRI by using patch-wise and full-image fully convolutional networks," Journal of Image and Graphics, 23(10), pp. 1558-1570, (2018). https://doi.org/10.1109/icip.2018.8451820
• Vopat, B. G., Cai, W., Torriani, M., Vopat, M. L., Hemma, M., Harris, G. J., Schantz, K., and Provencher, M. T., "Measurement of glenoid bone loss with 3-dimensional magnetic resonance imaging: a matched computed tomography analysis," Arthroscopy: The Journal of Arthroscopic & Related Surgery, 34(12), pp. 3141-3147, (2018). https://doi.org/10.1016/j.arthro.2018.06.050
• Guo, Y., Li, W., Cai, W., Zhang, Y., Fang, Y., and Hong, G., "Diagnostic value of gadoxetic acid-enhanced MR imaging to distinguish HCA and its subtype from FNH: a systematic review," International journal of medical sciences, 14(7), p. 668, (2017). https://doi.org/10.7150/ijms.17865
• Guo, Y., Li, W., Xie, Z., Zhang, Y., Fang, Y., Cai, W., and Hong, G., "Diagnostic value of Gd-EOB-DTPA-MRI for hepatocellular adenoma: a meta-analysis," Journal of Cancer, 8(7), p. 1301, (2017). https://doi.org/10.7150/jca.17778
• Ahlawat, S., Fayad, L. M., Khan, M. S., Bredella, M. A., Harris, G. J., Evans, D. G., Farschtschi, S., Jacobs, M. A., Chhabra, A., Salamon, J. M., Wenzel, R., Mautner, V. F., Dombi, E., Cai, W., Plotkin, S. R., and Blakeley, J. O., "Current whole-body MRI applications in the neurofibromatoses: NF1, NF2, and schwannomatosis," Neurology, 87(7 Supplement 1), pp. S31-S39, (2016). https://doi.org/10.1212/wnl.0000000000002929
• Hong, G. and Cai, W., "Advanced quantitative imaging analysis technologies for assessment of tumor response in clinical oncology," Chinese Journal of Radiology, 50(12), pp. 117-119, (2016).
• Lu, D., Wu, Y., Harris, G., and Cai, W., "Iterative mesh transformation for 3D segmentation of livers with cancers in CT images," Computerized Medical Imaging and Graphics, 43, pp. 1-14, (2015). https://doi.org/10.1016/j.compmedimag.2015.01.006
• Luo, M., Duan, C., Qiu, J., Li, W., Zhu, D., and Cai, W., "Diagnostic value of multidetector CT and its multiplanar reformation, volume rendering and virtual bronchoscopy postprocessing techniques for primary trachea and main bronchus tumors," PLoS One, 10(9), p. e0137329, (2015). https://doi.org/10.1371/journal.pone.0137329
• Shen, H., Dai, G., Luo, M., Duan, C., Cai, W., Liang, D., Wang, X., Zhu, D., Li, W., and Qiu, J., "Image quality and radiation dose of CT coronary angiography with automatic tube current modulation and strong adaptive iterative dose reduction three-dimensional (AIDR3D)," PloS one, 10(11), p. e0142185, (2015). https://doi.org/10.1371/journal.pone.0142185
• Shen, H., Liang, D., Luo, M., Duan, C., Cai, W., Zhu, S., Qiu, J., and Li, W., "Pilot study on image quality and radiation dose of CT colonography with adaptive iterative dose reduction three-dimensional," PloS one, 10(1), p. e0117116, (2015). https://doi.org/10.1371/journal.pone.0117116
• Cai, W., Lee, J.-G., Zhang, D., Kim, S. H., Zalis, M., and Yoshida, H., "Electronic cleansing in fecal-tagging dual-energy CT colonography based on material decomposition and virtual colon tagging," IEEE Transactions on Biomedical Engineering, 62(2), pp. 754-765, (2014). https://doi.org/10.1109/embc.2012.6346779
• Merker, V. L., Bredella, M. A., Cai, W., Kassarjian, A., Harris, G. J., Muzikansky, A., Nguyen, R., Mautner, V. F., and Plotkin, S. R., "Relationship between whole‐body tumor burden, clinical phenotype, and quality of life in patients with neurofibromatosis," American Journal of Medical Genetics Part A, 164(6), pp. 1431-1437, (2014). https://doi.org/10.1002/ajmg.a.36466
• Nguyen, R., Jett, K., Harris, G. J., Cai, W., Friedman, J. M., and Mautner, V.-F., "Benign whole body tumor volume is a risk factor for malignant peripheral nerve sheath tumors in neurofibromatosis type 1," Journal of neuro-oncology, 116(2), pp. 307-313, (2014). https://doi.org/10.1007/s11060-013-1293-1
• Cai, W. and de Moya, M., "Use of multidetector computed tomography to guide management of pneumothorax," Current opinion in pulmonary medicine, 19(4), pp. 387-393, (2013). https://doi.org/10.1097/mcp.0b013e32836094be
• Cai, W., Kim, S. H., Lee, J.-G., and Yoshida, H., "Informatics in radiology: dual-energy electronic cleansing for fecal-tagging CT colonography," Radiographics, 33(3), pp. 891-912, (2013). https://doi.org/10.1148/rg.333125039
• Cai, W., Zhang, D., Lee, J.-G., Shirai, Y., Kim, S. H., and Yoshida, H., "Dual-energy index value of luminal air in fecal-tagging computed tomography colonography: findings and impact on electronic cleansing," Journal of computer assisted tomography, 37(2), pp. 183-194, (2013). https://doi.org/10.1097/rct.0b013e31827bc266
• Chen, Z.-Y., Shen, H.-S., Luo, M.-Y., Duan, C.-J., Cai, W.-L., Lu, H.-B., Zhang, G.-P., Liu, Y., and Liang, J. Z., "Pilot study on efficacy of reduced cathartic bowel preparation with polyethylene glycol and bisacodyl," World Journal of Gastroenterology: WJG, 19(4), p. 561, (2013). https://doi.org/10.3748/wjg.v19.i4.561
• Smith, M. J., Esparza, S., Merker, V. L., Muzikansky, A., Bredella, M. A., Harris, G. J., Kassarjian, A., Cai, W., Walker, J. A., and Mautner, V. F., "Plasma S100β is not a useful biomarker for tumor burden in neurofibromatosis," Clinical biochemistry, 46(7-8), pp. 698-700, (2013). https://doi.org/10.1016/j.clinbiochem.2012.12.007
• Cai, W., Lee, J.-G., Fikry, K., Yoshida, H., Novelline, R., and de Moya, M., "MDCT quantification is the dominant parameter in decision-making regarding chest tube drainage for stable patients with traumatic pneumothorax," Computerized Medical Imaging and Graphics, 36(5), pp. 375-386, (2012). https://doi.org/10.1016/j.compmedimag.2012.03.005
• Plotkin, S. R., Bredella, M. A., Cai, W., Kassarjian, A., Harris, G. J., Esparza, S., Merker, V. L., Munn, L. L., Muzikansky, A., and Askenazi, M., "Quantitative assessment of whole-body tumor burden in adult patients with neurofibromatosis," PloS one, 7(4), p. e35711, (2012). https://doi.org/10.1371/journal.pone.0035711
• Xu, Y., Cai, W., Nappi, J., and Yoshida, H., "Fecal-tagging CT colonography with structure-analysis electronic cleansing for detection of colorectal flat lesions," European journal of radiology, 81(8), pp. 1712-1716, (2012). https://doi.org/10.1016/j.ejrad.2011.04.051
• Zalis, M. E., Blake, M. A., Cai, W., Hahn, P. F., Halpern, E. F., Kazam, I. G., Keroack, M., Magee, C., Näppi, J. J., and Perez-Johnston, R., "Diagnostic accuracy of laxative-free computed tomographic colonography for detection of adenomatous polyps in asymptomatic adults: a prospective evaluation," Annals of internal medicine, 156(10), pp. 692-702, (2012). https://doi.org/10.7326/0003-4819-156-10-201205150-00005
• Cai, W., Lee, E. Y., Vij, A., Mahmood, S. A., and Yoshida, H., "MDCT for computerized volumetry of pneumothoraces in pediatric patients," Academic radiology, 18(3), pp. 315-323, (2011). https://doi.org/10.1016/j.acra.2010.11.008
• Cai, W., Lee, J.-G., Zalis, M. E., and Yoshida, H., "Mosaic decomposition: An electronic cleansing method for inhomogeneously tagged regions in noncathartic CT colonography," IEEE transactions on medical imaging, 30(3), pp. 559-574, (2010). https://doi.org/10.1117/12.771206
• Cai, W., Yoshida, H., Zalis, M. E., Näppi, J. J., and Harris, G. J., "Informatics in radiology: electronic cleansing for noncathartic CT colonography: a structure-analysis scheme," Radiographics, 30(3), pp. 585-602, (2010). https://doi.org/10.1148/rg.303095154
• Cai, W., Kassarjian, A., Bredella, M. A., Harris, G. J., Yoshida, H., Mautner, V. F., Wenzel, R., and Plotkin, S. R., "Tumor burden in patients with neurofibromatosis types 1 and 2 and schwannomatosis: determination on whole-body MR images," Radiology, 250(3), pp. 665-673, (2009). https://doi.org/10.1148/radiol.2503080700
• Cai, W., Tabbara, M., Takata, N., Yoshida, H., Harris, G. J., Novelline, R. A., and de Moya, M., "MDCT for automated detection and measurement of pneumothoraces in trauma patients," American Journal of Roentgenology, 192(3), pp. 830-836, (2009). https://doi.org/10.2214/ajr.08.1339
• Nagata, K., Singh, A. K., Sangwaiya, M. J., Näppi, J., Zalis, M. E., Cai, W., and Yoshida, H., "Comparative evaluation of the fecal-tagging quality in CT colonography: barium vs. iodinated oral contrast agent," Academic radiology, 16(11), pp. 1393-1399, (2009). https://doi.org/10.1016/j.acra.2009.05.003
• Cai, W., Zalis, M. E., Näppi, J., Harris, G. J., and Yoshida, H., "Structure‐analysis method for electronic cleansing in cathartic and noncathartic CT colonography," Medical physics, 35(7Part1), pp. 3259-3277, (2008). https://doi.org/10.1118/1.2936413
• Nagata, K., Näppi, J., Cai, W., and Yoshida, H., "Minimum-invasive early diagnosis of colorectal cancer with CT colonography: techniques and clinical value," Expert opinion on medical diagnostics, 2(11), pp. 1233-1246, (2008). https://doi.org/10.1517/17530059.2.11.1233
• Cai, W., "3D planar reformation of vascular central axis surface with biconvex slab," Computerized Medical Imaging and Graphics, 31(7), pp. 570-576, (2007). https://doi.org/10.1016/j.compmedimag.2007.06.007
• Cai, W., Harris, G., Holalkere, N., Sahani, D., and Yoshida, H., "In-vivo and ex-vivo assessment of the accuracy of the computer-aided volumetry of porcine kidney in CT images," International Journal of Computer Assisted Radiology and Surgery (Print), 2(Suppl. 1), pp. S384-S386, (2007).
• Cai, W., Harris, G. J., and Yoshida, H., "Computation of vesselness in CTA images for fast and interactive vessel segmentation," International Journal of Image and Graphics, 7(01), pp. 159-176, (2007). https://doi.org/10.1142/s021946780700260x

Awards

• RSNA 2019 Certificate of Merit Award. Wenli Cai, Ying Li, Jonathan Hall, Guanghua Tan, Jinghui Lu, How to Build a Reliable and Reproducible Radiomics Application.
• RSNA 2016 Certificate of Merit Award. Wenli Cai and Gordon Harris, Volumetric tumor quantification of Neurofibromatosis in MRI.
• RSNA 2016 Certificate of Merit Award. Wenli Cai, Bhanusupriya Somarouthu, Yunpeng Liu, Anand Singh, Gordon Harris, Quantification of tumor viability using textures analysis.
• RSNA 2015 Cum Laude Award. Wenli Cai and Michael Zalais, Electronic Cleansing in CT Colonography: Past, Present, and Future.
• RSNA 2014 Certificate of Merit Award. Wenli Cai, Da Zhang, Bob Liu, Michael Zalis, Radiation dose and image quality for low dose fecal-tagging CT colonography ─ A comparison of electronic cleansing between single-energy and dual-energy CTC.
• RSNA 2011 Magna Cum Laude Award. Wenli Cai, June-Goo Lee, Se Hyung Kim, Hiroyuki Yoshida, Dual-energy Electronic Cleansing for Fecal-tagging CT Colonography.
• RSNA 2010 Certificate of Merit Award. Hiroyuki Yoshida, Yin Wu, Wenli Cai, Sharp Brett, et al. Cloud-computing CT Colonography with Gesture-based Reading Interface.
• RSNA 2009 Certificate of Merit Award. Wenli Cai, June-Goo Lee, Se Hyung Kim, Hiroyuki Yoshida, Dual-energy Electronic Cleansing for Fecal-tagging CT Colonography.
• RSNA 2008 Certificate of Merit Award. Anand Singh, Hiroyuki Yoshida, Wenli Cai, Janne Nappi, Gordon Harris, et al. Virtual Endoscopy in Abdominal MDCT: The Story So Far.
• RSNA 2007 Certificate of Merit Award. Hiroyuki Yoshida, Janne Nappi, Wenli Cai, Michael Zalis, et al. ColonChecker 2007: CAD Workstation for Detection of Polyps in Laxative-free Colonography.