HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Figures Only Full Text (PDF) All Versions of this Article: 2333031018v1 233/3/793    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Li, F. Articles by Doi, K. Search for Related Content PubMed PubMed Citation Articles by Li, F. Articles by Doi, K.

Malignant versus Benign Nodules at CT Screening for Lung Cancer: Comparison of Thin-Section CT Findings¹

¹ From the Kurt Rossmann Laboratories for Radiologic Image Research, Department of Radiology, University of Chicago, 5841 S Maryland Ave, Chicago, IL 60637 (F.L., H.A., H.M., K.D.), and J. A. Azumi General Hospital, Ikeda, Nagano, Japan (S.S.). From the 2002 RSNA scientific assembly. Received June 30, 2003; revision requested September 9; final revision received February 27, 2004; accepted April 12. Supported in part by USPHS grant CA62625. Address correspondence to F.L. (e-mail: fli@kurt.bsd.uchicago.edu).

	ABSTRACT

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
PURPOSE: To evaluate thin-section computed tomographic (CT) characteristics of malignant nodules on the basis of overall appearance (pure ground-glass opacity [GGO], mixed GGO, or solid opacity) in comparison with the appearance of benign nodules.

MATERIALS AND METHODS: Institutional review board approval and patient consent were obtained. Follow-up diagnostic CT was performed in 747 suspicious pulmonary nodules detected at low-dose CT screening (17 892 examinations). Of 747 nodules, 222 were evaluated at thin-section CT (1-mm collimation), which included 59 cancers and 163 benign nodules (3–20 mm). Thin-section CT findings of malignant versus benign nodules with pure GGO (17 vs 12 lesions), mixed GGO (27 vs 29 lesions), or solid opacity (15 vs 122 lesions) were analyzed. Fisher exact test for independence was used to compare differences in shape, margin, and internal features between benign and malignant nodules. Positive predictive value (PPV) was analyzed when a category was significantly different from the others.

RESULTS: Among nodules with pure GGO, a round shape was found more frequently in malignant lesions (11 of 17, 65%) than in benign lesions (two of 12, 17%; P = .02; PPV, 85%); mixed GGO, a subtype with GGO in the periphery and a high-attenuation zone in the center, was seen much more often in malignant lesions (11 of 27, 41%) than in benign lesions (two of 29, 7%; P = .004; PPV, 85%). Among solid nodules, a polygonal shape or a smooth or somewhat smooth margin was present less frequently in malignant than in benign lesions (polygonal shape: 7% vs 38%, P = .02; smooth or somewhat smooth margin: 0% vs 63%, P < .001), and 98% (46 of 47) of polygonal nodules and 100% (77 of 77) of nodules with a smooth or somewhat smooth margin were benign.

CONCLUSION: Recognition of certain characteristics at thin-section CT can be helpful in differentiating small malignant nodules from benign nodules.

© RSNA, 2004

Index terms: Cancer screening • Computed tomography (CT), thin-section • Lung neoplasms, CT, 60.1211 • Lung neoplasms, diagnosis, 60.31, 60.32

	INTRODUCTION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Computed tomographic (CT) screening has increased the detection rate of early peripheral lung cancer in the United States and Japan (1,2). The results of the Early Lung Cancer Action Project, or ELCAP (1), suggested that nodules with pure (nonsolid) or mixed (partially solid) ground-glass opacity (GGO) at thin-section CT are more likely to be malignant than are those with solid opacity; among 44 nodules with GGO (19% of 233 nodules identified at baseline screening), 15 (34%) were confirmed to be malignant. On the other hand, most of the benign lesions were solid at CT, although some (approximately 15%) contained elements of GGO. According to the ELCAP data, 18% of nodules (five of 28) with pure GGO were malignant and 63% of nodules (10 of 16) with mixed GGO were malignant (1). To our knowledge, there are no previous studies that specifically compare thin-section CT characteristics between malignant lesions and benign lesions with pure GGO, mixed GGO, and solid opacity.

A 3-year lung cancer screening program has recently been completed in Japan by using low-dose CT and follow-up thin-section CT. We have previously reported that among 59 small (6–20 mm) lung adenocarcinomas, only 16 nodules (27%) showed solid opacity and the rest (73%) showed pure or mixed GGO at thin-section CT in this screening program (2). In another study (3), thin-section CT characteristics were compared between 25 very small (10 mm) cancers, 24 of which were adenocarcinomas, and 40 benign lesions, most of which were solid nodules. We found that by using a single CT feature, namely polygonal shape, and a three-dimensional ratio (maximum transverse diameter to maximum z-axis dimension of a lesion, which was measured as the difference between the cephalic extent and the caudal extent of the lesion in coronal reformation) greater than 1.78, 100% specificity was shown for benign nodules (3). However, these features were not necessarily applicable to benign lesions with GGO, especially not to those larger than 10 mm. Thus, the purpose of our study was to evaluate the thin-section CT characteristics of malignant nodules on the basis of the overall appearance (pure GGO, mixed GGO, or solid opacity) compared with the appearance of benign nodules.

	MATERIALS AND METHODS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Study Nodules
From May 1996 to March 1999, 17 892 examinations were performed in 7847 individuals (4288 men and 3559 women; mean age, 61 years) as part of an annual low-dose CT screening program for lung cancer in Nagano, Japan. A mobile unit equipped with a CT scanner (W950SR; Hitachi, Tokyo, Japan) was used to scan the chest with a tube current of 25 or 50 mA, a scanning time of 2 seconds per rotation of the x-ray tube (tube rotation time, 2 seconds), a table speed of 10 mm/sec (pitch of 2), 10-mm collimation, and a 10-mm reconstruction interval. The program was sponsored and supported by the Telecommunications Advancement Organization of Japan and was completed after 3 years. All subjects gave informed consent. Approval for review and research of the cases used in this study was obtained from our institutional review board at the University of Chicago.

Among those undergoing the examinations, 605 patients with 747 suspicious pulmonary nodules detected at low-dose CT underwent follow-up diagnostic CT. Diagnostic work-up CT, which included thin-section CT, was performed within 3 months of low-dose CT screening; follow-up CT examinations were performed at 3, 6, 12, 18, and 24 months, as needed. Most of the follow-up CT examinations were performed at Shinshu University Hospital, and some were performed at local hospitals. The results for follow-up work were accrued until December 1999.

The follow-up results for the 747 nodules include six categories, as follows: 76 primary lung cancers confirmed at biopsy; 11 atypical adenomatous hyperplasias confirmed at biopsy; 444 lesions, which included 167 resolved nodules, 230 nodules that were stable for 2 years or more, 38 nodules with benign-pattern calcifications (diffuse, central, popcorn, and laminar or concentric calcification), and nine nodules that were resected and confirmed as benign; 27 nodules with findings suspicious for malignancy at thin-section CT but not confirmed at biopsy; 176 nodules suspected of being benign but with insufficient follow-up; and 13 indeterminate nodules.

For this study, we used a database of thin-section CT images obtained from Shinshu University Hospital as part of the Nagano CT screening program for lung cancer. A helical scanner (HiSpeed Advantage; GE Medical Systems, Milwaukee, Wis) was used for scanning the nodules with a 200-mA tube current, 1 second per tube rotation, table speed of 1 mm/sec, 1-mm collimation, and 0.5-mm interval with a bone reconstruction algorithm. The database consisted of studies performed in 222 patients with 222 confirmed malignant or confirmed benign nodules, which were small in size (3–20 mm) on the first thin-section CT image obtained within 3 months of low-dose CT screening. Among the 222 patients, there were 14 patients with two nodules in different lung lobes, in which case the larger of the two nodules was selected for this study. Patients with two nodules in the same lung lobe and patients with more than two nodules were not included. On thin-section CT images, nonnodular lesions such as linear or scattered opacities, which had been regarded as suspicious on the original 10-mm collimation screening CT images, were excluded from the analysis. Nodules with benign-pattern calcifications were also excluded. This database contained cases of 96 pulmonary nodules that were used in two previous studies (2,3).

Among the 222 patients (mean age, 62.4 years; age range, 30–84 years), there were 119 men (mean age, 62.8 years; age range, 30–84 years) and 103 women (mean age, 61.9 years; age range, 34–75 years).

Data Analysis
Thin-section CT images for the 222 nodules were displayed and interpreted with use of "stacked" mode on a monochrome cathode ray tube monitor at a width and level of 1500 HU and –550 HU, respectively. The images of 222 nodules were randomly arranged for a reading sequence, and the final diagnosis for the nodules, which included the histopathologic results, was blinded to the radiologists. Three radiologists with 20, 18, and 17 years of experience in general radiology (F.L. and H.A. included) independently viewed these images and subjectively classified the nodules as one of three patterns: pure GGO, mixed GGO, or solid opacity. They also independently determined the overall shape (round, oval, polygonal, or complex) and margin (smooth, somewhat smooth, somewhat irregular with slight spiculation, or irregular with spiculation) of the nodules, as well as the internal features. Internal features included a specific mixed GGO pattern characterized by GGO in the periphery, with a high-attenuation zone in the center and the presence or absence of air (air bronchogram, cavitation, or focal emphysema) within the nodule on thin-section CT images. The typical appearance of the three patterns, four shapes, and four margins used to classify the lesions is illustrated in Figure 1.

View larger version (45K): [in this window] [in a new window] [Download PPT slide]   Figure 1. Typical appearance of the three patterns, four shapes, and four margins used to classify lesions in this study.

Statistical Analysis
Statistical analysis was performed by using the Student t test for comparison of differences in size between benign and malignant nodules. The ² test for independence was used independently for comparison of the differences in patterns (nodules with and those without GGO) between the benign nodules and the malignant nodules. The data presented in Tables 1–3 were analyzed first by using the Fisher exact test for independence to determine whether there were any significant differences in the proportion of malignant lesions and benign lesions in the categories of shape, margin, and internal features. If such differences were established (the difference was significant at P .05), additional Fisher exact tests were performed to determine which categories were significantly different from the others. Fisher exact test was used instead of ² test because of the small sample size. Positive predictive value (PPV) was further analyzed when a category was significantly different from the others.

	RESULTS

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

All 17 malignant nodules with pure GGO were well-differentiated adenocarcinomas. Among 27 malignant nodules with mixed GGO, 26 were well-differentiated adenocarcinomas and one was a moderately differentiated adenocarcinoma. Of the 15 malignant nodules with solid opacity, four were well-differentiated adenocarcinomas, seven were other adenocarcinomas, two were squamous cell carcinomas, and two were small cell carcinomas. All 12 benign nodules with pure GGO had resolved at the 3-month follow-up examination. Among 29 benign nodules with mixed GGO, nodular fibrosis was confirmed at surgery in three cases, was resolved at 3 months or more of follow-up in 17 cases, and showed no change for 2 years or more in nine cases. Among the 122 benign solid nodules, five cases (one case each of inflammatory granuloma, cryptococcoma, focal organizing pneumonia, inflammatory pseudotumor, and sclerosing hemangioma) were confirmed at surgery, 19 cases were resolved at 3 months or more of follow-up, and 98 cases showed no change for 2 years or more. All malignant nodules were confirmed at surgery.

The distribution of sizes among 29 nodules with pure GGO, 56 with mixed GGO, and 137 with solid opacity is shown in Figure 2. For GGO lesions, there was extensive overlap between the size of benign nodules and that of malignant nodules. On the other hand, for solid lesions, there was relatively limited overlap between the size of benign nodules and that of malignant nodules.

View larger version (20K): [in this window] [in a new window] [Download PPT slide]   Figure 2. Graphs show distribution of sizes among, A, 29 nodules with pure GGO (17 malignant and 12 benign); B, 56 nodules with mixed GGO (27 malignant and 29 benign); and C, 137 nodules with solid opacity (15 malignant and 122 benign). Gray bars = malignant nodules, white bars = benign nodules. For pure and mixed GGO lesions, the size of benign nodules extensively overlaps that of malignant nodules in the 6-15-mm range.

View larger version (76K): [in this window] [in a new window] [Download PPT slide]   Figure 3. Transverse thin-section CT images. A, Image shows a malignant pure GGO lesion (adenocarcinoma) with a round shape (arrows). B, Image shows a benign pure GGO lesion (resolved within 3 months) with a polygonal-complex shape (arrows) that is confined to a secondary lobule.

View larger version (150K): [in this window] [in a new window] [Download PPT slide]   Figure 4. Transverse thin-section CT images. A, B, Images show a malignant mixed GGO lesion (adenocarcinoma) with irregular margins. The nodule shows both GGO in the periphery (arrows) and a high-attenuation zone (arrowhead) in the center. C, D, Images show a benign mixed GGO lesion (nodular fibrosis) with irregular margins. In C, a small air collection (arrowhead) is seen in the nodule. In D, the nodule (arrows) is seen on another section.

View larger version (83K): [in this window] [in a new window] [Download PPT slide]   Figure 5. Transverse thin-section CT images. A, Image shows a malignant nodule (squamous cell carcinoma) with air components (arrowhead) and an irregular margin and gross spiculation (arrows). B, Image shows a small benign solid nodule (stable for more than 2 years) with a polygonal shape (arrows) and somewhat smooth margin.

	DISCUSSION

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

Results of previous clinical CT studies (8–10) have shown that malignant nodules commonly contain solid opacity and that benign nodules have higher attenuation, often with visible calcifications, than do malignant nodules. Siegelman et al (10) reported that 61% of 279 benign nodules (including 153 nodules with diffuse calcifications) had smooth or moderately smooth margins and 65% of 283 primary malignant tumors had irregular shapes with spiculation. Kuriyama et al (5), in a study of 20 peripheral lung cancers and 20 benign nodules less than 20 mm in diameter, reported that an air bronchogram was not observed as frequently in small benign lesions, such as hamartoma and tuberculoma, as it was in adenocarcinomas.

The number of solid benign nodules was much greater than the total number of malignant nodules in our database, which was obtained from a lung cancer CT screening program, and the frequency of some features, such as internal air bronchograms, a complex shape, and an irregular margin, was much less in common in benign lesions than in malignant lesions. However, these observations do not necessarily mean that these features are reliable for differentiating benign nodules from malignant nodules, because the absolute numbers of benign nodules with such features may be comparable to the numbers of malignant nodules with similar features. For example, the frequency of an irregular margin in solid nodules was 7% (eight of 122) for benign nodules and 53% (eight of 15) for malignant nodules. However, if a radiologist encountered such a case in a screening examination, there would be an approximately 50% (eight of 16) likelihood that the lesion was malignant, if all other factors were equal. We found that a polygonal shape or a smooth or somewhat smooth margin (98%–100% likelihood of benignity) could be more helpful for differentiating solid benign nodules from malignant nodules than would internal air bronchograms, a complex shape, or an irregular margin.

There were some limitations to this study. For instance, no malignant lesions 5 mm or smaller were found; this is probably because the database used here was compiled from images obtained with low-dose single–detector row CT at a 10-mm section thickness. Second, many of the benign GGO lesions detected at the initial screening CT had resolved before thin-section diagnostic CT was performed. In a previous study, we reported that among 108 benign nodules (54, 27, and 27 of which showed pure GGO, mixed GGO, and solid opacity, respectively, at low-dose CT), 92 (85%) resolved within 3 months (11). Also, a large variance was noted in the judgment for CT features by three radiologists, especially for margins of the nodules; this is probably because most nodules used in current study were smaller than 10 mm.

The margins and size of nodules were not useful for differentiating benign from malignant GGO lesions in this series, and benign lesions with GGO were more difficult to distinguish from malignant nodules than were those with solid opacity. However, certain features, such as a round shape or a combination of GGO in the periphery with a high-attenuation zone in the center, were observed much more frequently in malignant GGO nodules. Therefore, we believe that familiarity with the different features of benign nodules and malignant nodules can be useful to radiologists in the management of indeterminate nodules. Also, short-term follow-up imaging can be helpful for differentiating benign from malignant nodules with GGO patterns, because all 12 of the benign pure GGO lesions in this series, as well as the majority of benign mixed GGO lesions, had partially or completely resolved within 3 months.

	ACKNOWLEDGMENTS

 
The authors are grateful to Chaotong Zhang, MD, for participating as an image reviewer, Qiang Li, PhD, for helpful suggestions, Masha Kocherginsky, PhD, for assistance with statistical analysis, Roger Engelmann, MS, for his useful work on the display software, and Elisabeth Lanzl for the English editing of the manuscript.

	FOOTNOTES

 
Abbreviations: GGO = ground-glass opacity, PPV = positive predictive value

H.M. and K.D. are shareholders of R2 Technology, Los Altos, Calif. K.D is a shareholder of Deus Technology, Rockville, Md.

Author contributions: Guarantors of integrity of entire study, F.L., S.S., K.D.; study concepts and design, F.L., K.D.; literature research, H.M., K.D.; clinical studies, F.L., S.S., H.A., H.M.; data acquisition, F.L., S.S.; data analysis/interpretation, F.L., H.A., H.M., K.D.; statistical analysis, F.L.; manuscript preparation, F.L.; manuscript definition of intellectual content, F.L., H.M., K.D.; manuscript editing, K.D., H.M.; manuscript revision/review and final version approval, all authors

	REFERENCES

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 

1. Henschke CI, Yankelevitz DF, Mirtcheva R, et al. CT screening for lung cancer: frequency and significance of part-solid and nonsolid nodules. AJR Am J Roentgenol 2002; 178:1053-1057.[Abstract/Free Full Text]
2. Yang ZG, Sone S, Takashima T, et al. High-resolution CT analysis of small peripheral lung adenocarcinomas revealed on screening helical CT. AJR Am J Roentgenol 2001; 176:1399-1407.[Abstract/Free Full Text]
3. Takashima S, Sone S, Li F, et al. Small solitary pulmonary nodules (< or = 1 cm) redetected at population-based CT screening for lung cancer: reliable high-resolution CT features of benign lesions. AJR Am J Roentgenol 2003; 180:955-964.[Abstract/Free Full Text]
4. Zwirewich CV, Vedal S, Miller RR, Müller NL. Solitary pulmonary nodule: high-resolution CT and radiologic-pathologic correlation. Radiology 1991; 179:469-476.[Abstract/Free Full Text]
5. Kuriyama K, Tateishi R, Doi O, et al. Prevalence of air bronchograms in small peripheral carcinomas of the lung on thin-section CT. AJR Am J Roentgenol 1991; 156:921-924.[Abstract/Free Full Text]
6. Li F, Sone S, Takashima S, et al. Correlations between high-resolution computed tomographic, magnetic resonance and pathological findings in cases with non-cancers but suspicious lung nodules. Eur Radiol 2000; 10:1782-1789.[CrossRef][Medline]
7. Kohno N, Ikezoe J, Johkoh T, et al. Focal organizing pneumonia: CT appearance. Radiology 1993; 189:119-123.[Abstract/Free Full Text]
8. Proto AV, Thomas SR. Pulmonary nodules studied by computed tomography. Radiology 1985; 156:149-153.[Abstract/Free Full Text]
9. Zerhouni EA, Stitik FP, Siegelman SS, et al. CT of the pulmonary nodule: a cooperative study. Radiology 1986; 160:319-327.[Abstract/Free Full Text]
10. Siegelman SS, Khouri NF, Leo FP, Fishman EK, Braverman RM, Zerhouni EA. Solitary pulmonary nodules: CT assessment. Radiology 1986; 160:307-312.[Abstract/Free Full Text]
11. Li F, Sone S, Takashima S, Maruyama Y, Hasegawa M, Yang ZG. Roentgenologic analysis of 108 non-cancerous focal lung lesions detected in screening CT for lung cancer. Jpn J Lung Cancer 1999; 39:369- 380.

This article has been cited by other articles:

				M. Infante, R. F. Lutman, S. Imparato, M. Di Rocco, G. L. Ceresoli, V. Torri, E. Morenghi, F. Minuti, S. Cavuto, E. Bottoni, et al. Differential diagnosis and management of focal ground-glass opacities Eur. Respir. J., April 1, 2009; 33(4): 821 - 827. [Abstract] [Full Text] [PDF]

				A. McWilliams and J. Mayo Computed Tomography-detected Noncalcified Pulmonary Nodules: A Review of Evidence for Significance and Management Proceedings of the ATS, December 15, 2008; 5(9): 900 - 904. [Abstract] [Full Text] [PDF]

				C. M. Park, J. M. Goo, T. J. Kim, H. J. Lee, K. W. Lee, C. H. Lee, Y. T. Kim, K. G. Kim, H. Y. Lee, E.-A. Park, et al. Pulmonary Nodular Ground-Glass Opacities in Patients With Extrapulmonary Cancers: What is Their Clinical Significance and How Can We Determine Whether They Are Malignant or Benign Lesions? Chest, June 1, 2008; 133(6): 1402 - 1409. [Abstract] [Full Text] [PDF]

				S. Oda, K. Awai, D. Liu, T. Nakaura, Y. Yanaga, H. Nomori, and Y. Yamashita Ground-Glass Opacities on Thin-Section Helical CT: Differentiation Between Bronchioloalveolar Carcinoma and Atypical Adenomatous Hyperplasia Am. J. Roentgenol., May 1, 2008; 190(5): 1363 - 1368. [Abstract] [Full Text] [PDF]

				T. J. Kim, J.-H. Lee, C.-T. Lee, S. H. Jheon, S. W. Sung, J.-H. Chung, and K. W. Lee Diagnostic Accuracy of CT-Guided Core Biopsy of Ground-Glass Opacity Pulmonary Lesions Am. J. Roentgenol., January 1, 2008; 190(1): 234 - 239. [Abstract] [Full Text] [PDF]

				D Patsios, H C Roberts, N S Paul, T Chung, S J Herman, A Pereira, and G Weisbrod Pictorial review of the many faces of bronchioloalveolar cell carcinoma Br. J. Radiol., December 1, 2007; 80(960): 1015 - 1023. [Abstract] [Full Text] [PDF]

				M. M. Wahidi, J. A. Govert, R. K. Goudar, M. K. Gould, and D. C. McCrory Evidence for the Treatment of Patients With Pulmonary Nodules: When Is It Lung Cancer?: ACCP Evidence-Based Clinical Practice Guidelines (2nd Edition) Chest, September 1, 2007; 132(3_suppl): 94S - 107S. [Abstract] [Full Text] [PDF]

				M. K. Gould, J. Fletcher, M. D. Iannettoni, W. R. Lynch, D. E. Midthun, D. P. Naidich, and D. E. Ost Evaluation of Patients With Pulmonary Nodules: When Is It Lung Cancer?: ACCP Evidence-Based Clinical Practice Guidelines (2nd Edition) Chest, September 1, 2007; 132(3_suppl): 108S - 130S. [Abstract] [Full Text] [PDF]

				C. M. Park, J. M. Goo, H. J. Lee, C. H. Lee, E. J. Chun, and J.-G. Im Nodular Ground-Glass Opacity at Thin-Section CT: Histologic Correlation and Evaluation of Change at Follow-up RadioGraphics, March 1, 2007; 27(2): 391 - 408. [Abstract] [Full Text] [PDF]

				Y. J. Jeong, C. A. Yi, and K. S. Lee Solitary Pulmonary Nodules: Detection, Characterization, and Guidance for Further Diagnostic Workup and Treatment Am. J. Roentgenol., January 1, 2007; 188(1): 57 - 68. [Abstract] [Full Text] [PDF]

				T. Ohtsuka, K.-i. Watanabe, M. Kaji, T. Naruke, and K. Suemasu A clinicopathological study of resected pulmonary nodules with focal pure ground-glass opacity. Eur. J. Cardiothorac. Surg., July 1, 2006; 30(1): 160 - 163. [Abstract] [Full Text] [PDF]

				M.-P. Revel, A. Merlin, S. Peyrard, R. Triki, S. Couchon, G. Chatellier, and G. Frija Software volumetric evaluation of doubling times for differentiating benign versus malignant pulmonary nodules. Am. J. Roentgenol., July 1, 2006; 187(1): 135 - 142. [Abstract] [Full Text] [PDF]

				M. B. McCarville, H. M. Lederman, V. M. Santana, N. C. Daw, S. J. Shochat, C.-S. Li, and R. A. Kaufman Distinguishing Benign from Malignant Pulmonary Nodules with Helical Chest CT in Children with Malignant Solid Tumors. Radiology, May 1, 2006; 239(2): 514 - 520. [Abstract] [Full Text] [PDF]

				H. T. Winer-Muram The solitary pulmonary nodule. Radiology, April 1, 2006; 239(1): 34 - 49. [Abstract] [Full Text] [PDF]

				F V Gleeson Is screening for lung cancer using low dose spiral CT scanning worthwhile? Thorax, January 1, 2006; 61(1): 5 - 7. [Full Text] [PDF]

				H. MacMahon, J. H. M. Austin, G. Gamsu, C. J. Herold, J. R. Jett, D. P. Naidich, E. F. Patz Jr, and S. J. Swensen Guidelines for Management of Small Pulmonary Nodules Detected on CT Scans: A Statement from the Fleischner Society Radiology, November 1, 2005; 237(2): 395 - 400. [Abstract] [Full Text] [PDF]

				F. Li, H. Arimura, K. Suzuki, J. Shiraishi, Q. Li, H. Abe, R. Engelmann, S. Sone, H. MacMahon, and K. Doi Computer-aided Detection of Peripheral Lung Cancers Missed at CT: ROC Analyses without and with Localization Radiology, November 1, 2005; 237(2): 684 - 690. [Abstract] [Full Text] [PDF]

This Article Abstract Figures Only Full Text (PDF) All Versions of this Article: 2333031018v1 233/3/793    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Li, F. Articles by Doi, K. Search for Related Content PubMed PubMed Citation Articles by Li, F. Articles by Doi, K.