GI-RADS

7/28/2019 GI-RADS

1/6

Ultrasound Obstet Gynecol2011; 38: 450455Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/uog.9012

GI-RADS reporting system for ultrasound evaluationof adnexal masses in clinical practice: a prospectivemulticenter study

F. AMOR*, J. L. ALCAZAR, H. VACCARO*, M. LEON and A. ITURRA

*Centro Ecografico Ultrasonic Panoramico, Santiago, Chile; Department of Obstetrics and Gynecology, Clinica Universidad de Navarra,University of Navarra, Pamplona, Spain; Department of Obstetrics and Gynecology, Cl nica Las Lilas, Santiago, Chile; Department ofObstetrics and Gynecology, Cl nica Indisa, Santiago, Chile

K E Y W O R D S: adnexal masses; ovarian cancer; reporting; ultrasound

ABSTRACT

Objective To assess the clinical usefulness of a structuredreporting system based on ultrasound findings formanagement of adnexal masses.

Methods This was a prospective multicenter study com-prising 432 adnexal masses in 372 women (mean age, 44.0(range, 1378) years) over a 36-month period. Ninety-three (25%) women were postmenopausal and 279 (75%)women were premenopausal. Patients were evaluatedwith transvaginal ultrasound by one of three examinersexpert in gynecological ultrasound. Reporting was pro-vided to referring clinicians according to the GynecologicImaging Report and Data System (GI-RADS) classifica-

tion. A predetermined management protocol was offeredto referral clinicians. It was suggested that patients clas-sified as GI-RADS 2 be managed with follow-up scan,

patients classified as GI-RADS 3 undergo laparoscopicsurgery and patients classified as GI-RADS 4 or 5 bereferred to a gynecologic oncologist. Definitive histologicdiagnosis was available in 370 cases and 62 additionalcases were considered as benign because of spontaneousresolution during follow-up. These outcomes were usedas the gold standard for calculating the sensitivity, speci-ficity, positive predictive value (PPV), negative predictivevalue (NPV), positive likelihood ratio (LR+) and nega-tive likelihood ratio (LR) of GI-RADS classification foridentifying adnexal masses at high risk of malignancy,considering GI-RADS 4 and 5 as being malignant.

Results Of the 432 tumors, 112 were malignant and320 benign. The GI-RADS classification rate was asfollows: GI-RADS 2, 92 (21%) cases; GI-RADS 3, 184(43%) cases; GI-RADS 4, 40 (9%) cases; GI-RADS 5,(27%) 116 cases. Sensitivity for this system was 99.1%(95% CI, 95.199.8%), specificity was 85.9% (95% CI,

81.789.3%), LR+ was 7.05 (95% CI, 5.379.45) andLR was 0.01 (95% CI, 0.0010.07). PPV and NPVwere 71.1% and 99.6%, respectively.

Conclusions The GI-RADS reporting system performedwell in identifying adnexal masses at high risk ofmalignancy and seems to be useful for clinical decision-making. Copyright 2011 ISUOG. Published by JohnWiley & Sons, Ltd.

INTRODUCTION

Ultrasonography is currently considered as the pri-

mary imaging modality for identifying and character-izing adnexal masses1. Several approaches have beenproposed for their characterization using this tech-nique, includingexaminerssubjective impression2, simpledescriptive scoring systems3, mathematically developedscoring systems4, logistic regression models5 and neuralnetworks6.

Subjective impression of an experienced examiner iscurrently believed to be the best approach and no othermethod has been proven its superior7,8. However, theexaminers impression is entirely subjective and recentevidence has shown that this fact affects not only theperformance of the method itself9, but also the exam-

iners confidence in providing a diagnosis10. Furthermore,a recent randomized study demonstrated that examinerexperience affects performance and decision-making inclinical practice11.

Due to the subjective nature of the examiners impres-sion there is a need for a standardized nomenclatureand definition for all tumor features evaluated by ultra-sound. This was provided by the International OvarianTumor Analysis (IOTA) consensus12. Undoubtedly, this

Correspondence to: Dr J. L. Alcazar, Department of Obstetrics and Gynecology, Clinica Universidad de Navarra, Avenida Pio XII, 36,

31008 Pamplona, Spain (e-mail: [email protected])

Accepted: 17 March 2011

Copyright 2011 ISUOG. Published by John Wiley & Sons, Ltd. ORIGINAL PAPER

7/28/2019 GI-RADS

2/6

GI-RADS reporting of adnexal masses 451

consensus has allowed a better, homogeneous descriptionof adnexal masses. However, there is still significantvariation in the reporting of ultrasound examinationresults for adnexal masses13. In fact, a recent consensusconference of the Society of Radiologists in Ultrasoundconcluded that investigation into structured reporting ofadnexal cysts to allow for improved communication of

results and recommendations for follow-up is needed14.In 2009 we proposed a reporting system similar to

that used for breast ultrasound (BI-RADS): the Gyne-cology Imaging Reporting and Data System (GI-RADS),developed to facilitate communication between sonol-ogists/sonographers and referring clinicians15. This GI-RADS classification is based on ultrasound findings,representing a summarized standardized report of thosefindings and also providing an estimated risk of malig-nancy for a given adnexal mass.

The aim of this study was to assess prospectively theuse of this reporting systemfor decision-making in clinicalpractice.

S U B J E C T S A N D M E T H O D S

This was a prospective study comprising all women diag-nosed as having an adnexal mass and evaluated at twodifferent centers, one in Spain (Clinica Universidad deNavarra, Pamplona) and one in Chile (Centro EcograficoUltrasonic Panoramico, Santiago), from January 2008to December 2010. Institutional review board approvalwas obtained and all women gave informed consent toparticipate.

All patients were evaluated by transvaginal or transrec-

tal (in cases of virgo-intacta women) ultrasound usinga Voluson 730 Expert or Pro machine (GE MedicalSystems, Zipf, Austria) according to a predeterminedscanning protocol15. Three expert examiners (F.A., H.V.and J.L.A.), each with more than 15 years experiencein gynecological ultrasound, performed all examinationsand between one and five representative images werestored on the machines database, to be used in the report(Figure S1 online).

Reporting was performed according to GI-RADSclassification15. This system is based on pattern recog-nition analysis and provides an a priori risk estimation of

probability of malignancy, based on data from previous

studies1517. The reporting system includes five categories

(Table 1) and the report includes a description of the mass

as well as a final GI-RADS classification (Figure S1).

During the examination, tumor volume was also esti-

mated according to the prolate ellipsoid formula (length

width height 0.5233, expressed in mL), but this

feature was not taken into consideration for assigning aGI-RADS classification.

The meaning and goal of GI-RADS classification was

explained to referring clinicians in several clinical sessions

before the study started. A management protocol was

offered to referral clinicians with the aim of determining

whether this reporting system could be useful for decid-

ing patient management and in avoiding confusion for

clinicians. However, while we followed up patients to

determine how they were managed ultimately, we were

not involved in clinical decision-making.

The suggested management protocol was based on

risk of malignancy as estimated by GI-RADS classifica-tion. Those patients classified as GI-RADS 1 (e.g. normal

ovaries at ultrasound) were excluded from the study and

from further analysis. GI-RADS 2 patients were consid-

ered for expectant management by follow-up sonography

on the basis that these lesions were assumed to be func-

tional. GI-RADS 3 patients underwent surgery by general

gynecologists on the basis that these lesions were consid-

ered to be probably benign and expected to persist over

time. Laparoscopy was preferable, although the surgeon

managing the patient made the final decision regarding

surgical approach (laparoscopy or laparotomy). Patients

classified as GI-RADS 4 and 5 were referred to gyne-cological oncologists for appropriate additional imaging

techniques (computed tomography or magnetic resonance

imaging) and surgical management, on the basis that these

lesions were considered to be probably or very probably

malignant.

When surgical removal of the tumor was performed,

a definitive histologic diagnosis was obtained. Tumors

were classified according to World Health Organization

criteria18 and malignant tumors were staged according

to FIGO criteria19. Borderline tumors were considered as

Table 1 Gynecologic Imaging Report and Data System (GI-RADS) classification system for adnexal masses

GI-RADSgrade Diagnosis

Est. prob.malignancy Detail

1 Definitive benign 0% Normal ovaries identified and no adnexal mass seen2 Very probably benign 20% Adnexal masses with three or more findings suggestive of malignancy*

*Thick papillary projections, thick septations, solid areas and/or ascites, defined according to IOTA criteria12, and vascularization withinsolid areas, papillary projections or central area of a solid tumor on color or power Doppler assessment5. Est. prob., estimated probability.

Copyright 2011 ISUOG. Published by John Wiley & Sons, Ltd. Ultrasound Obstet Gynecol2011; 38: 450455.

7/28/2019 GI-RADS

3/6

452 Amor et al.

malignant for analytic purposes. STARD guidelines werefollowed for designing and conducting the study20.

Statistical analysis

Categorical variables were compared using the chi-square test and tumor volumes were compared using

the MannWhitney U-test. We calculated the sensitivity,specificity, positive predictive value (PPV), negative pre-dictive value (NPV), positive likelihood ratio (LR+) andnegative likelihood ratio (LR) of the GI-RADS systemfor identifying adnexal masses at high risk of malignancy,considering GI-RADS 2 and 3 as low risk and GI-RADS 4and 5 as high risk. The gold standard was histologic diag-nosis (benign or malignant) or spontaneous resolution ofthe cyst during follow-up (benign).

To determine how useful they found the GI-RADSreporting system for understanding ultrasound findingsand for making decisions regarding patient management,referral clinicians involved in patient clinical decision-

making were asked to complete a simple survey. Thissurvey consisted of a single question: How useful doyou think GI-RADS reporting system is for understandingultrasound findings and giving confidence in clinical deci-sions regarding your patient? and there were five possibleanswers: (A) totally useful; (B) quite useful; (C) neitheruseful nor useless; (D) useless; (E) completely useless.

To assess interobserver reproducibility of GI-RADSclassification, two examiners (J.L.A. and A.I.) performeda separate analysis in 60 consecutive women who werealready included in the study. Both examiners performeda transvaginal scan, blinded to each others results, and

each one provided a GI-RADS report. To determinethe concordance between examiners we used a weightedKappa index.

R E S U L T S

A total of 372 women with adnexal masses were includedin this study (279 fromthe ClnicaUniversidad de Navarraand 93 from Centro Ecografico Ultrasonic Panoramico).Their mean age was 44 (range, 1378) years. Ninety-three (25%) women were postmenopausal and279 (75%)

were premenopausal. Sixty (16%) patients had bilateraltumors, giving a total number of 432 adnexal massesassessed. The prevalence of malignant tumors was 26%(112 malignant tumors in 87 patients). Malignant tumorswere more frequent in postmenopausal women (43.2%)than in premenopausal women (13.2%) (P < 0.001).

Of the 432 masses assessed, 92 (21%) were classifiedas GI-RADS 2, 184 (43%) as GI-RADS 3, 40 (9%) asGI-RADS 4 and 116 (27%) as GI-RADS 5. Tumor vol-ume was significantly smaller in GI-RADS 2 and 3 casescompared with GI-RADS 4 and 5 cases, while there wasno difference in tumor volume between GI-RADS 2 and 3

cases or between GI-RADS 4 and 5 cases (Table 2). Mostreferring clinicians managed their patients according toGI-RADS classification. Figure 1 summarizes the classi-fications, management and final outcomes of the studypopulation, and final histological diagnoses are given inTable 3.

There was no malignant tumor classified as GI-RADS2. There was one such case classified as GI-RADS 3;this false-negative case was a 73-year-old woman with a580 mLcyst diagnosedas benignserouscyst, buthistologyshowed it to be a serous ovarian carcinoma, Stage Ia.

Thesensitivity fortheGI-RADS reportingsystemin pre-

dicting malignancy was 99.1% (95% CI, 95.199.8%),specificity was 85.9% (95% CI, 81.789.3%), LR+ was7.05 (95% CI, 5.37 9.45) and LR was 0.01 (95% CI,

432 masses372 women

GI-RADS 3184 masses155 women




Follow-up86 masses

Spontaneousresolution71 masses

Persistence15 masses

Histologybenign

6 masses

Surgery15 masses

Histologybenign

15 masses

Spontaneousresolution2 masses

Histologybenign

181 masses

Histologymalignant

1 mass

Histologybenign

3 masses

Histologybenign

29 masses

Histologymalignant8 masses

Histologybenign

13 masses

Histologymalignant103 masses

Surgeryfor pain

symptoms6 masses

Follow-up2 masses

Surgery:general

gynecologist182 masses

Surgery:general

gynecologist3 masses

Referral:gynecologic

oncologist37 masses

Referral:gynecologic

oncologist116 masses

Figure 1 Flow chart showing classification by Gynecologic Imaging Report and Data System (GI-RADS), management and final outcome ofthe study group of 372 women with 432 adnexal masses.


7/28/2019 GI-RADS

4/6


Table 2 Tumor volume according to Gynecologic Imaging Reportand Data System (GI-RADS) in 372 women with 432 adnexal masses

Tumor volume (mL)

Median Interquartile range Range

GI-RADS 2a 32.0 16.772.0 3.9170.0

GI-RADS 3b 52.6 25.1 117.1 1.62677.7GI-RADS 4c 96.3 38.9 302.9 6.92237.1GI-RADS 5d 106.0 41.9 326.4 2.13728.9

a vs b: P = 0.130; a vs c: P = 0.01; a vs d: P = 0.001; b vs c:P = 0.028; b vs d: P = 0.0001; c vs d: P = 0.684.

0.0010.07) (Table 4). The PPV and NPV were 71.1%and 99.6%, respectively.

All fifteen (six in Spain and nine in Chile) referringclinicians considered this reporting system to be quiteuseful or useful for clinical decision-making in adnexalmasses.

The interobserveragreement forGI-RADSclassificationof adnexal masses was very good (weighted kappa index= 0.846) (Table 5).

D I S C U S S I O N

Reporting in ultrasound evaluation of adnexal massesis an important issue. A recent study from Canada hasshown that current reporting practices for ultrasoundassessments in women with ovarian masses vary consid-erably and concluded that the use of a synoptic reportingsystem would be useful13. Inappropriate reporting may

lead to unwarranted concern by the patient and referring

Table 4 Diagnostic performance of Gynecologic Imaging Reportand Data System (GI-RADS) reporting system in 372 women with432 adnexal masses

Number of tumors classified as:

Final diagnosis GI-RADS 2 3 GI-RADS 4 5 Total

Malignant 1 111 112Benign 275 45 320Total 276 156 432

clinician and could lead to unnecessary additional testsand surgery21. In fact, investigation into structured report-ing of adnexal masses to allow for improved communica-tion of results and recommendations for management hasbeen advised recently14.

For this reason we recently developed a simple report-ing system based on the concept developed for breastimaging (the BI-RADS classification), which was orig-

inally developed for mammographic findings but hasbeen applied successfully to breast ultrasound. As forBI-RADS, the lexicon of our new system is intended toprovide a unified language for ultrasound reporting andto avoid confusion in the communication between thesonographer/sonologist and the clinician. We called thisreporting system GI-RADS15. In the present study weassessed prospectively the use of our GI-RADS report-ing system for ultrasound evaluation of adnexal massesand clinical decision-making. A strength of the study isthat the ultrasound examiners were not involved in thedecision-making process.

The GI-RADS reporting system is based on the use

of pattern recognition analysis of the tumor2 and the

Table 3 Gynecologic Imaging Report and Data System (GI-RADS) classification according to specific histologic diagnosis in 372 womenwith 432 adnexal masses

Number of tumors classified as:

Histologic diagnosis GI-RADS 2 GI-RADS 3 GI-RADS 4 GI-RADS 5 Total

Functional cyst* 71 2 0 0 73Serous cystadenoma 5 36 7 0 48Mucinous cystadenoma 0 10 4 3 17Endometrioma 6 78 2 0 86

Teratoma 0 28 4 0 32Paraovarian cyst 0 3 0 0 3Hemorrhagic cyst 9 2 0 0 11Cystadenofibroma 1 5 3 2 11Peritoneal cyst 0 3 2 0 5Fibroma 0 3 6 3 12Hydrosalpinx 0 9 2 1 12Tubo-ovarian abscess 0 2 0 1 3Leiomyoma 0 0 1 1 2Brenner tumor 0 2 1 2 5Low malignant potential tumor 0 0 2 12 14Primary ovarian cancer 0 1 5 75 81Metastatic cancer 0 0 1 16 17Total 92 184 40 116 432

*Spontaneous resolution at follow-up. Five hemorrhagic cysts and the cystadenofibroma comprised the six GI-RADS 2 cases whichunderwent surgery following diagnosis due to pain symptoms. Two hydrosalpinges and one serous cystadenofibroma comprised theGI-RADS 4 cases which underwent laparoscopic surgery by a general gynecologist.


7/28/2019 GI-RADS

5/6

454 Amor et al.

Table 5 Agreement analysis between two observers for assigning Gynecologic Imaging Report and Data System (GI-RADS) classification in60 women with unilateral adnexal masses

Examiner A

Examiner B GI-RADS 2 GI-RADS 3 GI-RADS 4 GI-RADS 5 Total

GI-RADS 2 10 1 0 0 11

GI-RADS 3 1 21 3 0 25GI-RADS 4 0 2 9 0 11GI-RADS 5 0 0 2 11 13Total 11 24 14 11 60

Data are given as number of tumors.

a-priori risk of malignancy of differenttumor features1517.Although one could argue that pattern recognition is asubjective assessment, there is evidence that this is thebest method for characterizing adnexal masses7,8 andthat pattern recognition is reproducible among expertexaminers2224.

In terms of diagnostic performance, this reporting sys-tem performed well, with a very high sensitivity andacceptable specificity. This is not surprising bearing inmind that it is based on IOTA criteria, which have beentestedextensively in several multicenter studies and shownto be good criteria for discriminating between benign andmalignant adnexal masses2527. However, one possibleselection bias in our study is the relatively high preva-lence of malignant tumors, which could affect estimationof sensitivity and specificity. Notwithstanding, both PPVand NPV were high and these figures are not affected bydisease prevalence.

Our data have shown that the GI-RADS classifica-tion system is useful for clinical decision-making andreferral. Furthermore, all referring clinicians involved inpatient management considered it to be useful. We there-fore propose a standardized nomenclature for reportingultrasound findings of adnexal masses, applying the samerationale as that of BI-RADS classification for breastultrasound. While it is true that adequate referral may beachieved using logistic models such as the risk malignancyindex28,29, scoring systems30 or just pattern recognitionanalysis as does IOTA31, a standardizedreportingnomen-clature is lacking. To the best of our knowledge, this isthe first such standardized reporting/classification system

applicable to adnexal masses.It is likely that this reporting system would not be

needed in those institutions where ultrasound examinersand clinicians participating in clinical decision-makinghave good and direct communication and decisions aboutpatient management are collegiate, or even in those prac-tices where expert sonologists themselves decide abouttheir own patients management. However, this systemcould be useful in those settings in which clinicians man-aging patients do not perform ultrasound examinations,instead reading the report of the morphological descrip-tion of the tumor. It could alsobeuseful for small hospitalsand for private practitioner-gynecologists who must referpatients with suspicious masses to tertiary care hospitalswith gynecologic oncology facilities.

There were some limitations to the study. A possi-ble bias is that expert examiners performed all ultra-sound examinations; this is known to potentially affectdiagnostic performance when using pattern recognitionanalysis9,32. Therefore, further research into how thisreporting system performs when used by non-expert

examiners is needed. Another bias of this study is thata management protocol according to GI-RADS classifica-tion was offered to referral clinicians before starting thestudy. This could have biased their decision as to howto manage the patients. An interesting issue regardingthe suggested management protocol is the use of surgeryin cases of GI-RADS 3. In fact, expectant managementcould also be offered safely to these patients33. A furtherweakness of this study is the fact that most GI-RADS 4lesions were benign, although they were classified as beingprobably malignant. However, there was still a 20% riskof malignancy (8/40). One option for improving the pre-dictive value of this group would be further classificationinto subgroups depending on degree of likelihood ofmalignancy according to the examiners impression.

In conclusion, this prospective study has shown thatGI-RADS classification performs well as a reporting sys-tem in adnexal masses and it seems to be useful for clinicaldecision-making.

R E F E R E N C E S

1. ACOG Practice Bulletin. Management of adnexal masses.American College of Obstetricians and Gynecologists. ObstetGynecol2007; 110: 201214.

2. Valentin L. Pattern recognition of pelvic masses by gray-scaleultrasound imaging: the contribution of Doppler ultrasound.Ultrasound Obstet Gynecol1999; 14: 338347.

3. Granberg S, Wikland M, Jansson I. Macroscopic characteriza-tion of ovarian tumors and the relation to the histologicaldiagnosis: criteria to be used for ultrasound evaluation. GynecolOncol1989; 35: 139144.

4. Alcazar JL, Merce LT, Laparte C, Jurado M, Lopez-Garca G.A new scoring system to differentiate benign from malignantadnexal masses. Am J Obstet Gynecol2003; 188: 685692.

5. Alcazar JL, Errasti T, Laparte C, Jurado M, Lopez-Garca G.Assessment of a new logistic model in the preoperativeevaluation of adnexal masses. J Ultrasound Med 2001; 20:841848.

6. Timmerman D, Verrelst H, BourneTH, DeMoorB, Collins WP,

Vergote I, Vandewalle J. Artificial neural network models forthe preoperative discrimination between malignant and benignadnexal masses. Ultrasound Obstet Gynecol1999; 13: 1725.


7/28/2019 GI-RADS

6/6


7. Valentin L, Hagen B, Tingulstad S, Eik-Nes S. Comparisonof pattern recognition and logistic regression models fordiscrimination between benign and malignant pelvic masses: aprospective cross validation. Ultrasound Obstet Gynecol2001;18: 357365.

8. Timmerman D. The use of mathematical models to evaluatepelvic masses; can they beat an expert operator? Best Pract ResClin Obstet Gynaecol2004; 18: 91104.

9. Van Holsbeke C, Daemen A, Yazbek J, Holland TK, Bourne T,Mesens T, Lannoo L, Boes AS, Joos A, Van De Vijver A,Roggen N, de Moor B, de Jonge E, Testa AC, Valentin L,Jurkovic D, Timmerman D. Ultrasound experience substantiallyimpacts on diagnostic performance and confidence whenadnexal masses are classified using pattern recognition. GynecolObstet Invest2010; 69: 160168.

10. Yazbek J, Ameye L, Testa AC, Valentin L, Timmerman D,Holland TK, Van Holsbeke C, Jurkovic D. Confidenceof expertultrasound operators in making a diagnosis of adnexal tumor:effect on diagnostic accuracy and interobserver agreement.Ultrasound Obstet Gynecol2010; 35: 8993.

11. Yazbek J, Raju SK, Ben-Nagi J, Holland TK, Hillaby K,Jurkovic D. Effect of quality of gynaecological ultrasonogra-phy on management of patients with suspected ovarian cancer:a randomised controlled trial. Lancet Oncol2008; 9: 124131.

12. Timmerman D, Valentin L, Bourne TH, Collins WP, Ver-relst H, Vergote I; International Ovarian Tumor Analysis(IOTA) Group. Terms,definitionsand measurements to describethe sonographic features of adnexal tumors: a consensus opin-ion from the International Ovarian Tumor Analysis (IOTA)Group. Ultrasound Obstet Gynecol2000; 16: 500505.

13. Le T, Fayadh RA, Menard C, Hicks-Boucher W, Faught W,Hopkins L, Fung-Kee-Fung M. Variations in ultrasound report-ing on patients referred for investigation of ovarian masses.

J Obstet Gynaecol Can 2008; 30: 902906.14. Levine D, Brown DL, Andreotti RF, Benacerraf B, Benson CB,

Brewster WR, Coleman B, Depriest P, Doubilet PM, Gold-stein SR, Hamper UM, Hecht JL, Horrow M, Hur HC, Mar-nach M, Patel MD, Platt LD, Puscheck E, Smith-Bindman R.Management of asymptomatic ovarian and other adnexal cystsimaged at US: Society of Radiologists in Ultrasound ConsensusConference Statement. Radiology 2010; 256: 943954.

15. Amor F, Vaccaro H, Alcazar JL, Leon M,Craig JM, Martinez J.Gynecologic imaging reporting and data system: a new proposalfor classifying adnexal masses on the basis of sonographicfindings. J Ultrasound Med2009; 28: 285291.

16. Guerriero S, Ajossa S, Garau N, Piras B, Paoletti AM, Melis GB.Ultrasonography and color Doppler-based triage for adnexalmasses to provide the most appropriate surgical approach. Am

J Obstet Gynecol2005; 192: 401406.17. Alcazar JL, Royo P, Jurado M, Mnguez JA, Garca-Manero M,

Laparte C, Galvan R, Lopez-Garca G. Triage for surgicalmanagement of ovarian tumors in asymptomatic women:assessment of an ultrasound-based scoring system. Ultrasound

Obstet Gynecol2008; 32: 220225.18. Scully RE, Sobin LH. WHO histological classification ofovarian tumors. World Health Organization: Geneva, 1999.

19. Heintz AP, Odicino F, Maisonneuve P, Quinn MA, Benedet JL,Creasman WT, Ngan HY, Pecorelli S, Beller U. Carcinoma oftheovary. FIGO 6thAnnual Report on the Results of Treatmentin Gynecological Cancer. Int J Gynaecol Obstet 2006; 95:S161S192.

20. Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP,

Irwig LM, Lijmer JG, Moher D, Rennie D, de Vet HC. Stan-dards for Reporting of Diagnostic Accuracy. Towards completeand accurate reporting of studies of diagnostic accuracy: theSTARD initiative. Clin Radiol2003; 58: 575580.

21. Brown DL, Dudiak KM, Laing FC. Adnexal masses: US char-acterization and reporting. Radiology. 2010; 254: 342354.

22. Timmerman D, Schwarzler P, Collins WP, Claerhout F, CoenenM, Amant F, Vergote I, Bourne TH. Subjective assessment ofadnexal masses with the use of ultrasonography: an analysisof interobserver variability and experience. Ultrasound ObstetGynecol1999; 13: 1116.

23. Guerriero S, Alcazar JL, Pascual MA, Ajossa S, Gerada M,Bargellini R, Virgilio B, Melis GB. Intraobserver and interob-server agreement of grayscale typical ultrasonographic patternsfor the diagnosis of ovarian cancer. Ultrasound Med Biol2008;34: 17111716.

24. Guerriero S, Alcazar JL, Pascual MA, Ajossa S, Gerada M,Bargellini R, Virgilio B, Melis GB. Diagnosis of the mostfrequent benign ovarian cysts: is ultrasonography accurate andreproducible? J Womens Health 2009; 18: 519527.

25. Valentin L, Hagen B, Tingulstad S, Eik-Nes S. Comparisonof pattern recognition and logistic regression models fordiscrimination between benign and malignant pelvic masses: aprospective cross validation. Ultrasound Obstet Gynecol2001;18: 357365.

26. Valentin L, Ameye L, Jurkovic D, Metzger U, Lecuru F, VanHuffel S, Timmerman D. Which extrauterine pelvic masses aredifficult to correctly classify as benign or malignant on the basisof ultrasound findings and is there a way of making a correctdiagnosis? Ultrasound Obstet Gynecol2006; 27: 438444.

27. Sokalska A, Timmerman D, Testa AC, Van Holsbeke C, Lis-soni AA, Leone FP, Jurkovic D,Valentin L.Diagnostic accuracyof transvaginal ultrasound examination for assigning a specificdiagnosis to adnexal masses. Ultrasound Obstet Gynecol2009;34: 462470.

28. van den Akker PA, Aalders AL, Snijders MP, Kluivers KB,Samlal RA, Vollebergh JH, Massuger LF. Evaluationof the Riskof Malignancy Index in daily clinical management of adnexalmasses. Gynecol Oncol2010; 116: 384388.

29. Raza A, Mould T, Wilson M, Burnell M, Bernhardt L. Increas-ing the effectiveness of referral of ovarian masses from cancerunit to cancer center by using a higher referral value of the riskof malignancy index. Int J Gynecol Cancer 2010; 20: 552554.

30. Alcazar JL,Royo P, Jurado M, Mnguez JA, Garca-Manero M,Laparte C, Galvan R, Lopez-Garca G. Triage for surgicalmanagement of ovarian tumors in asymptomatic women:assessment of an ultrasound-based scoring system. UltrasoundObstet Gynecol2008; 32: 220225.

31. Yazbek J, Helmy S, Ben-Nagi J, Holland T, Sawyer E, JurkovicD. Value of preoperative ultrasoundexaminationin theselectionof women with adnexal masses for laparoscopic surgery.Ultrasound Obstet Gynecol2007; 30: 883888.

32. Van Holsbeke C, Daemen A, Yazbek J, Holland TK, Bourne T,

Mesens T, Lannoo L, De Moor B, De Jonge E, Testa AC,Valentin L, Jurkovic D, Timmerman D. Ultrasound methodsto distinguish between malignant and benign adnexal massesin the hands of examiners with different levels of experience.Ultrasound Obstet Gynecol2009; 34: 454461.

33. Alcazar JL, Castillo G, Jurado M, Garca GL. Is expectantmanagement of sonographically benign adnexal cysts an optionin selected asymptomatic premenopausal women? Hum Reprod2005; 20: 32313234.

S U P P O R T I N G I N F O R M A T I O N O N T H E I N T E R N E T

The following supporting information may be found in the online version of this article:

Figure S1 Sample report for the Gynecologic Imaging Report and Data System (GI-RADS) classification.


Documents

GI-RADS