1. bookVolume 54 (2020): Issue 4 (December 2020)
Journal Details
License
Format
Journal
eISSN
1581-3207
First Published
30 Apr 2007
Publication timeframe
4 times per year
Languages
English
Open Access

Adnexal masses characterized on 3 tesla magnetic resonance imaging – added value of diffusion techniques

Published Online: 21 Oct 2020
Volume & Issue: Volume 54 (2020) - Issue 4 (December 2020)
Page range: 419 - 428
Received: 19 Jun 2020
Accepted: 14 Sep 2020
Journal Details
License
Format
Journal
eISSN
1581-3207
First Published
30 Apr 2007
Publication timeframe
4 times per year
Languages
English
Introduction

Incidental adnexal masses are commonly detected in daily medical practice due to the frequent lack of clinical manifestation.1 Approximately 9% to 10% of women undergoing ultrasound have ovarian lesions.2 Although most commonly used, ultrasound has some limitations including the small field of view, low resolution and interference by obesity or by gaseous bowel loops.3 Ultrasound indeterminate adnexal masses vary between 5% and 25%.4, 5 If furthermore examined with computed tomography (CT), distant metastases, respectively the staging of the disease could be assessed. Magnetic resonance (MR) has been considered as the most useful imaging technique for characterizing adnexal formations. This modality has a key role in the preoperative evaluation and their follow-up, identifying the origin of the mass and the different types of tissue contained in with accuracy of 88% to 93%.6 3 Tesla MRI is superior for examining female pelvis due to its higher resolution and the possibility of providing more detailed images.7, 8, 9 MRI techniques such as diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) are of an additional benefit differentiating malignant from benign lesions.10, 11, 12,

The aim of our study is to assess different types of adnexal masses as identified by 3T MRI and to discuss the added value of diffusion and perfusion techniques compared with conventional sequences.

Patients and methods

174 women age between 13 and 87 underwent MRI examination of the pelvis for a period of three years. Indications were: sonographically detected pelvic mass; or gynecological complaints; or history of previous adnexal tumor; or family history of ovarian cancer. Six women were examined for other reasons (hips, sigma/colon or perianal abscess), nine for uterine pathology, but adnexal mass was detected and the complete gynecological MRI protocol was performed, too. At least one adnexal mass was diagnosed in 98 patients and they are subject of this study. 51% of them were reviewed retrospectively. Data from patients’ history, physical examination and laboratory tests were reviewed as well.

Patients were examined in two radiology departments, 135 of them on 3 Tesla MRI Siemens Verio and the 39 on 3 Tesla MRI Philips Ingenia. The Siemens MRI protocol included: coronal (COR) T1; sagittal (SAG) T2; paracoronal and paratransversal of the uterus T2 with and without fat saturation; SAG T1; transversal T1 Vibe Dixon; DWI and ADC. The Philips MRI protocol included: COR STIR; SAG T2; COR T2; COR T1; axial (AX) T2; AX T2 with fat saturation; DWI and ADC. (Table 1)

3 Tesla Siemens and 3 Tesla Philips MRI protocols

SIEMENS VERIO 3.0T
FOV (mm)Matrix (mm)Slice thickness (mm)TR (ms)TE (ms)Voxel size (mm)TA(min)
T1 COR300390/32055008.70.9×0.9×5.001:36
T2 SAG200320/320433001330.6×0.6×4.003:44
T2 paracor200320/320437001400.6×0.6×4.003:24
T2 paracor +FS200256/256437001310.8×0.8×4.001:58
T2 paratra200320/320437401480.6×0.6×4.003:29
T2 paratra + FS200256/256437001380.8×0.8×4.002:13
T1 SAG160217/1924569120.4×0.4×4.003:44
T1 vibe dixon AX380188/3203.53.921.270.6×0.6×3.500:19
DWI AX (b50-400-800)360100/12854700571.4×1.4×5.002:49
POST C
T1 vibe dixon AX380188/3203.53.921.270.6×0.6×3.500:19
T1 SAG160217/1924569120.4×0.4×4.003:44
T1 COR300390/32055008.70.9×0.9×5.001:36
PHILIPS INGENIA 3.0T
COR STIR340228/18655622501.5×1.5×5.003:45
T2 SAG229208/208337761001.1×1.1×3.003:01
COR T2315392/29754846900.8×1.6×5.001:56
COR T1315392/315548380.8×1.2×5.002:11
AX T2261328/251548051000.8×1.0×5.002:05
AX T2 FS261236/20854346801.11×1.25×5.002:37
DWI 3b 0,100,800375124/10645299773.0×3.0×4.001:51
POST C
MDixon AX240220/2223,55.41.961.09×1.08×3.502:58
COR T1 FS315392/309551980.8×1.02×5.002:17

AX = axial; COR = coronal; COR STIR = coronal short tau inversion recovery; DWI = diffusion-weighted imaging; FS = fat sat; paracor = paracoronal; SAG = sagital

Measurement of the ADC value was carried out for all ovarian masses in our study. For each tumor a region of interest (ROI: 1 cm2) was manually defined. In the mixed malignant formations ROIs were placed on the solid component only. The ADC values are presented as numerical value x 10-3 mm2/s representing quantitative metric.

Intravenous contrast administration was applied when needed and when there were no contraindications. A macrocyclic contrast agent Gadobutrol [1.0 mmol/ml] (Gadovist® 1.0, Bayerhealthcare, Berlin, Germany) was used at a dose of 0.1 mmol/ kg in all contrast-enhanced studies on both MR devices. Injection rate of 0.5 mL/sec was performed in order to achieve equimolar amounts of gadolinium. Saline flush (25–30 ml) at the same flow rate followed the contrast administration.

In part of our cases dynamic contrast enhanced – magnetic resonance imaging (DCE-MRI) was performed and time-signal intensity curve (TIC) was generated using the Mean Curve software package (Philips). A round region of interest (ROI: 1 cm2) was placed at target areas referring to T2W and contrast-enhanced images. Areas with hemorrhage and necrosis were avoided.

The following patterns were evaluated on MR images:

tumor appearance (cystic, solid or mixed)

uni- or bilateral ovaries involvement

size of the mass

adipose tissue presence or not

signal intensity on T2 weighted images

diffusion restriction

wall thickness

presence or not of septa

papillary projections

presence or not of ascites

lymph nodes involvement and metastases

Following MR criteria of malignancy, as reported in the literature (by Jeong et al.13, Valentini et al.6 and El-Wekil et al.14), are used:

lesion size more than 4 cm

solid components with heterogeneous enhancement

papillary projections

septa thick more than 3 mm

areas of necrosis and breaking down

lymph nodes involvement sized more than 1 cm.

SPSS Statistics release 21 for Microsoft Windows was used to perform Kolmogorov-Smirnov (2-tailed) test for establishing correlations between malignancy and diffusion restriction and between malignancy and type of mass.

Approval was obtained from the Institutional Review Board of both University hospitals prior the initiation of the study. Informed written consent was obtained from each patient. Personal identity information of all patients was protected.

Results

In 98 females of ave rage age 47.2 years, a total of 124 ovarian masses were detected. In 16 of the patients (16.3%) additional uterine pathology was found. One case considered as an ovarian cyst was histologically proven to be an inclusion peritoneal cyst. The results of all ovarian masses according to their MRI features are listed in Table 2.

Results of 124 ovarian masses according to their MRI features

MalignantBenignBorderline
Cystic masses5/41 (12.2%)61/71 (85.9%)6/12 (50%)
Solid masses10/41 (24.4%)4/71 (5.6%)2/12 (16.6%)
Mixed masses26/41 (63.4%)6/71 (8.5%)4/12 (33.4%)
Cases with one ovary involvement18/30 (60%)46/58 (79.3%)9/10 (90%)
Cases with both ovaries’ involvement12/30 (40%)12/58 (20.7%)1/10 (10%)
Size of the mass (more than 4 cm)37/41 (90.2%)22/71 (31%)8/12 (66.7%)
Masses with adipose tissue presence-5/71 (7%)1/12 (8.3%)
Masses with high signal intensity in T2WI5/41 (12.2%)42/71 (59.1%)5/12 (41.6%)
Masses with low signal intensity in T2WI7/41 (17.1%)18/71 (25.4%)1/12 (8.4%)
Heterogeneous masses29/41 (70.7%)11/71 (15.5%)6/12 (50%)
Diffusion restriction39/41 (95.1%)19/71 (26.8%)7/12 (58.4%)
Wall thickness (more than 3 mm)20/41 (48.8%)12/71 (16.9%)5/12 (41.7%)
Presence of septa25/41 (61%)11/71 (15.5%)5/12 (41.7%)
Papillary projections presented14/41 (34.1%)-2/12 (16.6%)
Cases with presence of ascites16/30 (53.3%)15/58 (25.9%)2/10 (20%)
Lymph nodes involvement and metastases20/30 (66.6%)3/58* (5.2%)1/10 (10%)

T2WI = T2 weighted imaging

Following the MRI criteria, 59.2% of the cases were considered benign, 30.6% malignant and 10.2% borderline. The results of DWI sequences show a statistically significant correlation with the assessment of masses as benign/borderline/malignant. 34.3% of all malignant cases were found in the age group 61–70. Of all patients 32 were tested for CA-125 tumor marker and 12 had elevated levels. Only half of those 12 cases were histologically proven malignant.

The biggest diameter of all 124 ovarian masses was measured – the largest one was 216 mm, the smallest one was under 10 mm. 54% of all tumors had diameter larger than 4 cm.

58.1% out of all mas ses were classified as cystic, 12.9% as solid and 29% as mixed. In four cases both solid and cystic masses were found in the same patient. Of all ovarian tumors 37 (29.8%) had wall thickness greater than 3 mm, 16 (12.9%) had papillary projections and 41 (33%) were septated. Only 6 masses of all contained fat, 5 of them were histologically proven to be mature teratomas. Kolmogorov-Smirnov test shows a statistically significant correlation between the type of mass and the assessment of masses as benign/borderline/malignant.

Оf histologically proven tumors 74.4% were benign and 25.6% were malignant. All masses classified on MRI as benign were identified correctly. Two masses, described as suspicious and malignant, turned out to be benign. All of the malignant tumors had restricted diffusion. The calculated ADC values of malignant adnexal masses are significantly lower than the ADC values of benign masses. Exceptions were found for endometrioma (1.01 ± 0.05 x 10-3 mm2/s); mature teratoma (0.80 ± 0.04 x 10–3 mm2/s) and chronic abscess (0.61 ± 0.06 x 10-3 mm2/s) – all of them presenting lower ADC values. (Figure 1) 72.7% of malignant neoplasms were mixed masses, 18.2% were solid and only one (9.1%) was cystic. Compared to them, 75% of benign tumors were cystic.

Figure 1

(A) Box plot presenting ADC values in four different types of adnexal tumors – highest ADC value found in a simple cyst; lowest found in a malignant tumor. (B) Mean apparent diffusion coefficient (ADC) values of twelve patients with histologically proven benign adnexal lesion and twelve patients with histologically proven malignant adnexal lesion. All values are expressed as mean value ± standard deviation (SD) x 10 -3 mm 2 /s.

64 out of all 98 patients underwent contrast enhancement. 34 there were a subject of contraindications (history of previous allergic reactions to the contrast agent, elevated levels of serum creatinine or patient refusal). 39 (61%) of the masses showed enhancement. Three were classified as benign and four – as suspicious. 32 of the enhanced tumors were identified as malignant.

Ascites was found in 33 of the cases – in 15 of which is located only in the pouch of Douglas. In 15.3% of the cases, enlarged lymph nodes with diffusion restriction were found – all in patients with malignant masses and one with a proven chronic inflammatory process. In 15 cases enlarged metastatic locoregional lymph nodes were found. Eight patients had peritoneal deposits; four patients liver metastases; three patients bone metastases, two patients were with urinary bladder invasion and one patient had adrenal metastasis. In all cases with metastases three turned out to be from uterine cancer (ovarian masses in these cases were proven benign).

Discussion

Assessing different types of adnexal lesions is important preoperatively. We find a number of reasons about the value of 3 Tesla MRI in such differentiation.

The MRI gynecological protocols we used concur the ESUR Quick Guide to Female Pelvis Imaging, 1.0 from 2019.15 Classical sequences (T1, T2) combined with post-gadolinium sequences and diffusion techniques provide reliable information on the nature of the adnexal masses.

It is known from previous studies that dynamic contrast enhanced MRI (DCE-MRI) is helpful in characterizing adnexal tumors. It could discriminate malignant from benign masses. According to the study of Thomassin-Naggara et al. there are three types of TIC showing benign, borderline and malignant ovarian tumors. Figure 2 demonstrates representative Type III curve of a malignant adnexal mass.

Figure 2

Type III time intensity curve (TIC) of a malignant adnexal mass.

The number of patients (98) in our study exceeds those of similar ones known from the literature (30 in El-Wekil et al.14 and 58 in Koc et al.16). The average age of patients (47.2 years) as well differs respectably by seven and four years from the cited studies.14, 16

The WHO histological classification (according to Foti et al.17) divides primary ovarian masses into three main categories: epithelial, germ cell and sex cord-stromal tumors. Metastatic tumors are classified in a separate category. In 2016 Meinhold-Heerlein et al. revised the WHO classification introducing seromucinous tumors as a new entity.18 Our study includes 14 histologically different groups of ovarian masses – ten benign and four malignant. Diffusion MRI appearance of histologically different groups is shown in Table 3. Some of the benign formations have diffusion restriction – abscess, endometrioma, mature cystic teratoma and serous adenofibroma. In 88% of cases mature cystic teratomas are filled with sebaceous material and are lined with keratinized squamous epithelium19, compared to the most relevant feature – adipose tissue which is presented in only 67–75%.20 Diffusion restriction is caused by the presence of keratin or Rokitansky nodule and fat globules.21 Endometriomas as containing blood and hemosiderin can show diffusion restriction too.21, 22 Solid areas with similar changes can help the detection of malignant transformation. When it comes to an ovarian abscess, diffusion characteristics depend on the content – in more viscous one the signal intensity is higher on DWI and lower on ADC map.23 Diffusion techniques could differentiate abscess from cystic or necrotic neoplasm. Neoplasms usually show diffusion restriction peripherally and abscesses centrally.22, 24 According to cystic degeneration, some adenofibromas also could be characterized by restriction of the water molecules.22 ,25 ,26

Diffusion MRI appearance of histologically different groups

Histopathological findingsDWI restrictedDWI Facilitated
Simple cyst-5
Inclusion cyst-1
Abscess1-
Endometrioma125
Teratoma5-
Serous cystadenoma-2
Mucinous cystadenoma11
Serous adenofibroma1-
Serous cystadenofibroma1-
Brenner tumor-1
Seromucinous carcinoma2-
Serous papillary adenocarcinoma2-
Adenosarcoma1-
Metastases6-

DWI = diffusion-weighted imaging

In this study adnexal masses are classified based on their morphological appearance, similar to Foti et. al.17 and divided into three main groups – cystic, solid and mixed (cystic and solid).

Cystic adnexal masses could be unilocular or multilocular. Some of them have a non-ovarian origin. They are usually benign, with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images.

Peritoneal inclusion cysts and hydrosalpinx are the most common extra ovarian lesions. They occur almost exclusively in premenopausal women and at imaging the ovaries are clearly separated from these cystic formations.27, 28

Functional ovarian cysts are the most common finding in women of reproductive age. Follicles are up to 20 mm as the dominant one could be 25 mm. Follicular cysts and corpus luteum cysts are larger and tend to increase if there is internal bleeding. This manifests with an increase of the signal on T1-weighted images.13, 17 They do not usually have diffusion restriction and does not change after contrast administration. Although, in corpus luteum cysts intense wall enhancement may be seen.

Serous cystadenoma and mucinous cystadenoma are benign tumors with thin walls (Figure 3). Mucinous type is usually larger, septated and has variable intensity on both T1- and T2-weighted images based on different mucin concentration. Some loculi are hyperintense on T1-weighted images, forming a pattern known as “honeycomb” or “stained glass”.17, 29, 30 Serous cystadenoma is more often bilateral and its wall could contain small nodules due to fibrosis or calcification.31, 32 Diffusion restriction could be detected in mucinous cystadenoma due to the dense mucinous material.12

Figure 3

45-year old patient with bilateral adnexal masses; serous papillary cystadenoma (arrow) and mucinous cystadenoma (arrowhead); both masses have predominantly high signal intensity on T2WI and T2WI fat sat (A), (B) and low signal intensity on T1WI fat sat (C).

Cystadenofibroma is usually a benign epithelial tumor that can present as a complex cystic mass with thick septa and solid component. It could present with plaques and nodules that have low signal intensity on T2-weighted images due to fibrous tissue (Figure 4).33, 34, 35

Figure 4

68-year old patient with previous hysterectomy; right serous cystadenofibroma (arrow); complex mass - heterogeneous on T2WI (A) which shows peripheral enhancement on T1WI fat sat with contrast (B). (C) Macroscopic histological preparation of the tumor.

Endometriomas are part of the cystic lesions containing blood products. In addition to that, they characterize with hyperintensity on T1-weighted images and lower signal intensity on T2-weighted images, called “shading sign”. Sometimes these lesions could have high signal intensity on both T1- and T2-weighed images. They do not change their signal intensity on fat-suppressed sequences13, 31, 36, 37 Patients having endometriosis are at risk of developing ovarian malignancies.38 Endometriomas usually do not enhance after contrast administration but could have restricted diffusion.11, 22

Mixed ovarian masses containing both cystic and solid parts are always suspicious for malignant – surface epithelial tumors and metastases. The benign representative of this category is mature cystic teratoma.

Mature cystic teratoma is known as the most common ovarian neoplasm that arises from ovarian germ cells.13, 31 Usually part of this tumor has high signal intensity on T1WI and intermediate on T2WI, fat-fluid or fluid-fluid level, low signal calcification parts and floating debris. It could also have a soft-tissue protuberance called Rokitansky nodule. On fat-suppressed sequences the areas containing fat show drop in signal intensity. Malignant transformation of mature cystic teratoma is rare.19, 37, 39, 40 Enhancement after contrast application is not typical. They could represent with restricted diffusion in the areas with keratin and fat globules.22, 23

Serous and mucinous cystadenocarcinoma are the most common epithelial malignancies of the ovaries – 50% and 10% of malignant lesions.41 Mucinous tumors are larger, lobulated and may be hyperintense on T1WI in addition to the high protein concentration in mucoid material.30, 42 Cystadenocarcinomas have thick and irregular walls, septations, solid components and papillary projections that have low signal intensity on T2WI with contrast enhancement after contrast administration. Serious fluid part demonstrates with high signal intensity on T2WI (Figure 5). Peritoneal invasion is sometimes discovered.17, 41 In connection with their malignant nature, a pronounced diffusion restriction is observed.

Figure 5

57- year old patient with left serous papillary adenocarcinoma (arrow); predominantly cystic mass with high signal intensity on T2WI (A) and solid component which is enhanced on T1WI fat sat with contrast (B). Part of the mass characterizes with diffusion restriction (C). (D) Microscopy preparation of the tumor.

Ovarian metastases most frequently originate from a primary process in the female genital tract, gastrointestinal tract (Krukenberg tumor) or breast. They are more commonly bilateral and multiloculated. Their solid parts are hypointense on T2WI and enhance after gadolinium administration. Distinguishing them from a primary ovarian process is not easy.17, 41, 43 Ovarian metastases have high signal intensity on DWI and low on ADC map (Figure 6).

Figure 6

63- year old patient with right ovarian metastasis from adenocarcinoma with intestinal phenotype; complex septated mass with heterogeneous signal intensity on T2WI (A); enhancement mostly in wall and septi on T1WI fat sat with contrast (B); part of the mass (arrowhead) has restricted diffusion; (D) Microscopy preparation of the metastasis.

Other less common representatives of mixed ovarian neoplasms are endometrioid tumors, yolk sac tumors and granulosa cell tumors.

Solid ovarian masses could have benign, borderline and malignant behavior. They include all three main histological types – epithelial, germ cell and sex cord tumors and metastases.

The Brenner tumor is a rare epithelial tumor and represents 2% of ovarian neoplasms.44 It is usually benign and has largely homogeneous low signal intensity on T1- and T2-weighed images. Its signal intensity is similar to those of fibromas but no cysts and necrosis are found in Brenner tumor. This ovarian tumor can occur in association with mucinous cystadenoma (Figure 7). Mild enhancement is observed after contrast application. Diffusion restriction is not characteristic of benign representatives of this tumor.39, 45

Figure 7

54- year old patient with mucinous cystadenoma (arrow) coexisting with benign Brenner tumor (arrowhead); mucinous cystadenoma has high signal intensity on T2WI (A) and low on T1WI fat sat (B); compared to it Brenner tumor has low signal intensity on T2WI (A) and high on T1WI fat sat (B); on T1 fat sat with contrast (C) only Brenner tumor shows enhancement and on DWI (D) only Brenner tumor shows restricted diffusion.

Fibromas encounter around 4% of all ovarian tumors. They could mimic malignant neoplasm as their size can vary and may be associated with ascites and pleural effusion (Meig syndrome). Another pathology they should be defined from is pedunculated uterine leiomyoma. These tumors demonstrate low signal intensity on both T1- and T2-weighted images. Scattered areas of high signal intensity could be present on T1WI due to cystic degeneration or edema.13, 17, 35 In this case diffusion restriction may be found. After contrast administration minimal enhancement is evident.

In this study 72.7% of histologically proven malignant neoplasms were mixed cystic and solid, 18.2% were solid and only one (9.1%) was cystic. That statement disagrees with El-Wekil et al.14 where no solid mass was found but cystic masses were 37.5% of their case series. However, 62.5% of tumors in their study were mixed cystic and solid which roughly coincides with our findings.

All of the histologically proven malignant lesions in this study show restricted diffusion. This confirms the literature data that an adnexal mass with higher signal intensity on DWI and lower on ADC map usually is a malignant lesion. Our results confirm the findings of previous studies in the literature that benign adnexal lesions have higher ADC values than the malignant once. We also found some exceptions of this statement concerning endometrioma, mature teratoma and chronic abscess presenting with lower ADC values despite of their benign origin.

Borderline ovarian tumors are usually complex masses that have some of the MR characteristics of the malignant one. They could show cellular proliferation and moderate nuclear atypia but without stromal invasion.46, 47 Similar to the study of Bent et. al.46 we identified 11 of the cases as suspicious. All of them demonstrated one or more MRI feature suggestive for malignancy – size more than 4 cm, solid part, cystic part with vegetations and septations, wall thickness more than 3 mm; contrast enhancement. In our study only one of the 10 suspicious cases were bilateral.

CA-125 is established tumor marker for ovarian cancer.13, 48 Limitation of this study is the small number of CA-125 tests performed before magnetic resonance imaging. Of these, elevated levels of CA-125 were found in 12 patients. Similarly, to other studies, over 60% of our patients with elevated CA-125 levels have proven malignant ovarian lesions.

Concerning unilateral or bilateral adnexal masses, we found malignant to be more often bilateral. Unilateral lesions are more often found in the right adnexa and in younger patients. This study as well as the Zhang et al. one49 suggests that large sizes and atypical signal intensity may influence the correct assessment of the type of ovarian lesions. The main limitations of our study include the retrospective reviewing of patients with some clinical missing, as well as surgical missing findings in patients who underwent surgery in another hospital.

Conclusions

Classifying adnexal masses is essential for the preoperative management of the patients. 3T MRI protocols, in particular diffusion techniques, increase significantly the accuracy of the diagnostic assessment. Further studies correlated with histological validation would support the role of MRI as a mandatory part of the patients’ management.

Figure 1

(A) Box plot presenting ADC values in four different types of adnexal tumors – highest ADC value found in a simple cyst; lowest found in a malignant tumor. (B) Mean apparent diffusion coefficient (ADC) values of twelve patients with histologically proven benign adnexal lesion and twelve patients with histologically proven malignant adnexal lesion. All values are expressed as mean value ± standard deviation (SD) x 10 -3 mm 2 /s.
(A) Box plot presenting ADC values in four different types of adnexal tumors – highest ADC value found in a simple cyst; lowest found in a malignant tumor. (B) Mean apparent diffusion coefficient (ADC) values of twelve patients with histologically proven benign adnexal lesion and twelve patients with histologically proven malignant adnexal lesion. All values are expressed as mean value ± standard deviation (SD) x 10 -3 mm 2 /s.

Figure 2

Type III time intensity curve (TIC) of a malignant adnexal mass.
Type III time intensity curve (TIC) of a malignant adnexal mass.

Figure 3

45-year old patient with bilateral adnexal masses; serous papillary cystadenoma (arrow) and mucinous cystadenoma (arrowhead); both masses have predominantly high signal intensity on T2WI and T2WI fat sat (A), (B) and low signal intensity on T1WI fat sat (C).
45-year old patient with bilateral adnexal masses; serous papillary cystadenoma (arrow) and mucinous cystadenoma (arrowhead); both masses have predominantly high signal intensity on T2WI and T2WI fat sat (A), (B) and low signal intensity on T1WI fat sat (C).

Figure 4

68-year old patient with previous hysterectomy; right serous cystadenofibroma (arrow); complex mass - heterogeneous on T2WI (A) which shows peripheral enhancement on T1WI fat sat with contrast (B). (C) Macroscopic histological preparation of the tumor.
68-year old patient with previous hysterectomy; right serous cystadenofibroma (arrow); complex mass - heterogeneous on T2WI (A) which shows peripheral enhancement on T1WI fat sat with contrast (B). (C) Macroscopic histological preparation of the tumor.

Figure 5

57- year old patient with left serous papillary adenocarcinoma (arrow); predominantly cystic mass with high signal intensity on T2WI (A) and solid component which is enhanced on T1WI fat sat with contrast (B). Part of the mass characterizes with diffusion restriction (C). (D) Microscopy preparation of the tumor.
57- year old patient with left serous papillary adenocarcinoma (arrow); predominantly cystic mass with high signal intensity on T2WI (A) and solid component which is enhanced on T1WI fat sat with contrast (B). Part of the mass characterizes with diffusion restriction (C). (D) Microscopy preparation of the tumor.

Figure 6

63- year old patient with right ovarian metastasis from adenocarcinoma with intestinal phenotype; complex septated mass with heterogeneous signal intensity on T2WI (A); enhancement mostly in wall and septi on T1WI fat sat with contrast (B); part of the mass (arrowhead) has restricted diffusion; (D) Microscopy preparation of the metastasis.
63- year old patient with right ovarian metastasis from adenocarcinoma with intestinal phenotype; complex septated mass with heterogeneous signal intensity on T2WI (A); enhancement mostly in wall and septi on T1WI fat sat with contrast (B); part of the mass (arrowhead) has restricted diffusion; (D) Microscopy preparation of the metastasis.

Figure 7

54- year old patient with mucinous cystadenoma (arrow) coexisting with benign Brenner tumor (arrowhead); mucinous cystadenoma has high signal intensity on T2WI (A) and low on T1WI fat sat (B); compared to it Brenner tumor has low signal intensity on T2WI (A) and high on T1WI fat sat (B); on T1 fat sat with contrast (C) only Brenner tumor shows enhancement and on DWI (D) only Brenner tumor shows restricted diffusion.
54- year old patient with mucinous cystadenoma (arrow) coexisting with benign Brenner tumor (arrowhead); mucinous cystadenoma has high signal intensity on T2WI (A) and low on T1WI fat sat (B); compared to it Brenner tumor has low signal intensity on T2WI (A) and high on T1WI fat sat (B); on T1 fat sat with contrast (C) only Brenner tumor shows enhancement and on DWI (D) only Brenner tumor shows restricted diffusion.

Diffusion MRI appearance of histologically different groups

Histopathological findingsDWI restrictedDWI Facilitated
Simple cyst-5
Inclusion cyst-1
Abscess1-
Endometrioma125
Teratoma5-
Serous cystadenoma-2
Mucinous cystadenoma11
Serous adenofibroma1-
Serous cystadenofibroma1-
Brenner tumor-1
Seromucinous carcinoma2-
Serous papillary adenocarcinoma2-
Adenosarcoma1-
Metastases6-

Results of 124 ovarian masses according to their MRI features

MalignantBenignBorderline
Cystic masses5/41 (12.2%)61/71 (85.9%)6/12 (50%)
Solid masses10/41 (24.4%)4/71 (5.6%)2/12 (16.6%)
Mixed masses26/41 (63.4%)6/71 (8.5%)4/12 (33.4%)
Cases with one ovary involvement18/30 (60%)46/58 (79.3%)9/10 (90%)
Cases with both ovaries’ involvement12/30 (40%)12/58 (20.7%)1/10 (10%)
Size of the mass (more than 4 cm)37/41 (90.2%)22/71 (31%)8/12 (66.7%)
Masses with adipose tissue presence-5/71 (7%)1/12 (8.3%)
Masses with high signal intensity in T2WI5/41 (12.2%)42/71 (59.1%)5/12 (41.6%)
Masses with low signal intensity in T2WI7/41 (17.1%)18/71 (25.4%)1/12 (8.4%)
Heterogeneous masses29/41 (70.7%)11/71 (15.5%)6/12 (50%)
Diffusion restriction39/41 (95.1%)19/71 (26.8%)7/12 (58.4%)
Wall thickness (more than 3 mm)20/41 (48.8%)12/71 (16.9%)5/12 (41.7%)
Presence of septa25/41 (61%)11/71 (15.5%)5/12 (41.7%)
Papillary projections presented14/41 (34.1%)-2/12 (16.6%)
Cases with presence of ascites16/30 (53.3%)15/58 (25.9%)2/10 (20%)
Lymph nodes involvement and metastases20/30 (66.6%)3/58* (5.2%)1/10 (10%)

3 Tesla Siemens and 3 Tesla Philips MRI protocols

SIEMENS VERIO 3.0T
FOV (mm)Matrix (mm)Slice thickness (mm)TR (ms)TE (ms)Voxel size (mm)TA(min)
T1 COR300390/32055008.70.9×0.9×5.001:36
T2 SAG200320/320433001330.6×0.6×4.003:44
T2 paracor200320/320437001400.6×0.6×4.003:24
T2 paracor +FS200256/256437001310.8×0.8×4.001:58
T2 paratra200320/320437401480.6×0.6×4.003:29
T2 paratra + FS200256/256437001380.8×0.8×4.002:13
T1 SAG160217/1924569120.4×0.4×4.003:44
T1 vibe dixon AX380188/3203.53.921.270.6×0.6×3.500:19
DWI AX (b50-400-800)360100/12854700571.4×1.4×5.002:49
POST C
T1 vibe dixon AX380188/3203.53.921.270.6×0.6×3.500:19
T1 SAG160217/1924569120.4×0.4×4.003:44
T1 COR300390/32055008.70.9×0.9×5.001:36
PHILIPS INGENIA 3.0T
COR STIR340228/18655622501.5×1.5×5.003:45
T2 SAG229208/208337761001.1×1.1×3.003:01
COR T2315392/29754846900.8×1.6×5.001:56
COR T1315392/315548380.8×1.2×5.002:11
AX T2261328/251548051000.8×1.0×5.002:05
AX T2 FS261236/20854346801.11×1.25×5.002:37
DWI 3b 0,100,800375124/10645299773.0×3.0×4.001:51
POST C
MDixon AX240220/2223,55.41.961.09×1.08×3.502:58
COR T1 FS315392/309551980.8×1.02×5.002:17

Expert Panel on Women’s Imaging, Atri M, Alabousi A, Reinhold C, Akin EA, Benson CB, Bhosale PR, et al. ACR Appropriateness CriteriaR clinically suspected adnexal mass, no acute symptoms. J Am Coll Radiol 2019; 16: S77-93. doi: 10.1016/j.jacr.2019.02.011ExpertPanel on Women’s ImagingAtriMAlabousiAReinholdCAkinEABensonCBBhosalePRet alACR Appropriateness CriteriaR clinically suspected adnexal mass, no acute symptomsJ Am Coll Radiol201916S779310.1016/j.jacr.2019.02.011Open DOISearch in Google Scholar

Sharma A, Apostolidou S, Burnell M, Campbell S, Habib M, Gentry-Maharaj A, et al. Risk of epithelial ovarian cancer in asymptomatic women with ultrasound-detected ovarian masses: a prospective cohort study within the UK collaborative trial of ovarian cancer screening (UKCTOCS). Ultrasound Obstet Gynecol 2012. 40: 338-44. doi: 10.1002/uog.12270SharmaAApostolidouSBurnellMCampbellSHabibMGentry-MaharajAet alRisk of epithelial ovarian cancer in asymptomatic women with ultrasound-detected ovarian masses: a prospective cohort study within the UK collaborative trial of ovarian cancer screening (UKCTOCS)Ultrasound Obstet Gynecol2012403384410.1002/uog.12270Open DOISearch in Google Scholar

Biggs WS, Marks ST. Diagnosis and management of adnexal masses. Am Fam Physician 2016; 93: 676-81. PMID: 27175840BiggsWSMarksSTDiagnosis and management of adnexal massesAm Fam Physician20169367681PMID: 27175840Search in Google Scholar

Van Calster B, Timmerman D, Valentin L, McIndoe A, Ghaem-Maghami S, Testa AC, et al. Triaging women with ovarian masses for surgery: observational diagnostic study to compare RCOG guidelines with an International Ovarian Tumour Analysis (IOTA) group protocol. BJOG 2012; 119: 662-71. doi: 10.1111/j.1471-0528.2012.03297.xVanCalster BTimmermanDValentinLMcIndoeAGhaem-MaghamiSTestaACet alTriaging women with ovarian masses for surgery: observational diagnostic study to compare RCOG guidelines with an International Ovarian Tumour Analysis (IOTA) group protocolBJOG20121196627110.1111/j.1471-0528.2012.03297.xOpen DOISearch in Google Scholar

Thomassin-Naggara I, Poncelet E, Jalaguier-Coudray A, Guerra A, Fournier LS, Stojanovic S, et al. Ovarian-adnexal reporting data system magnetic resonance imaging (O-RADS MRI) score for risk stratification of sonographically indeterminate adnexal masses. JAMA Netw Open 2020; 3: e1919896. doi: 10.1001/jamanetworkopen.2019.19896Thomassin-NaggaraIPonceletEJalaguier-CoudrayAGuerraAFournierLSStojanovicSet alOvarian-adnexal reporting data system magnetic resonance imaging (O-RADS MRI) score for risk stratification of sonographically indeterminate adnexal massesJAMA Netw Open20203e191989610.1001/jamanetworkopen.2019.19896Open DOISearch in Google Scholar

Valentini AL, Gui B, Miccò M, Mingote MC, De Gaetano AM, Ninivaggi V, et al. Benign and suspicious ovarian masses-MR imaging criteria for characterization: Pictorial review. J Oncol 2012; 2012: 481806. doi: 10.1155/2012/481806ValentiniALGuiBMiccòMMingoteMCDe GaetanoAMNinivaggiVet alBenign and suspicious ovarian masses-MR imaging criteria for characterization: Pictorial reviewJ Oncol2012201248180610.1155/2012/481806Open DOISearch in Google Scholar

Kataoka M, Kido A, Koyama T, Isoda H, Umeoka S, Tamai K, et al. MRI of the female pelvis at 3T compared to 1.5T: evaluation on high-resolution T2-weighted and HASTE images. J Magn Reson Imaging 2007; 25: 527-34. doi: 10.1002/jmri.20842KataokaMKidoAKoyamaTIsodaHUmeokaSTamaiKet alMRI of the female pelvis at 3T compared to 1.5T: evaluation on high-resolution T2-weighted and HASTE imagesJ Magn Reson Imaging2007255273410.1002/jmri.20842Open DOISearch in Google Scholar

Léautaud A, Marcus C, Ben Salem D, Bouché O, Graesslin O, Hoeffel C. Pelvic MRI at 3.0 Tesla. J Radiol 2009; 90: 277-86. doi: 10.1016/s0221-0363(09)72506-5LéautaudAMarcusCBen SalemDBouchéOGraesslinOHoeffelCPelvic MRI at 3.0 Tesla. J Radiol2009902778610.1016/s0221-0363(09)72506-5Open DOISearch in Google Scholar

Hussain SM, van den Bos IC, Oliveto JM, Martin DR. MR imaging of the female pelvis at 3T. Magn Reson Imaging Clin N Am 2006; 14: 537-44, vii. doi: 10.1016/j.mric.2007.01.008HussainSMvan den BosICOlivetoJMMartinDRMR imaging of the female pelvis at 3TMagn Reson Imaging Clin N Am2006145374410.1016/j.mric.2007.01.00817433982Open DOISearch in Google Scholar

Thomassin-Naggara I, Balvay D, Rockall A, Carette MF, Ballester M, Darai E, et al. Added value of assessing adnexal masses with advanced MRI techniques. Biomed Res Int 2015; 2015: 785206. doi: 10.1155/2015/785206Thomassin-NaggaraIBalvayDRockallACaretteMFBallesterMDaraiEet alAdded value of assessing adnexal masses with advanced MRI techniquesBiomed Res Int2015201578520610.1155/2015/785206456459426413542Open DOISearch in Google Scholar

Davarpanah AH, Kambadakone A, Holalkere NS, Guimaraes AR, Hahn PF, Lee SI. Diffusion MRI of uterine and ovarian masses: identifying the benign lesions. Abdom Radiol 2016; 41: 2466-75. doi: 10.1007/s00261-016-0909-2DavarpanahAHKambadakoneAHolalkereNSGuimaraesARHahnPFLeeSIDiffusion MRI of uterine and ovarian masses: identifying the benign lesionsAbdom Radiol20164124667510.1007/s00261-016-0909-227660280Open DOISearch in Google Scholar

Dhanda S, Thakur M, Kerkar R, Jagmohan P. Diffusion-weighted imaging of gynecologic tumors: diagnostic pearls and potential pitfalls Radiographics 2014; 34: 1393-416. doi: 10.1148/rg.345130131DhandaSThakurMKerkarRJagmohanPDiffusion-weighted imaging of gynecologic tumors: diagnostic pearls and potential pitfallsRadiographics201434139341610.1148/rg.345130131Open DOISearch in Google Scholar

Jeong YY, Outwater EK, Kang HK. Imaging evaluation of ovarian masses. Radiographics 2000; 20: 1445-70. doi: 10.1148/ radiographics.20.5.g00se101445JeongYYOutwaterEKKangHKImaging evaluation of ovarian massesRadiographics20002014457010.1148/radiographics.20.5.g00se101445Open DOISearch in Google Scholar

El-Wekil A, Mohammad S Abdullah MS, El-Kholy SS. The role of MRI in the differentiation between benign and malignant ovarian lesions. Menoufia Med J 2017; 32: 106-11. doi: 10.4103/mmj.mmj_548_17El-WekilAMohammadSAbdullahMSEl-KholySSThe role of MRI in the differentiation between benign and malignant ovarian lesionsMenoufia Med J2017321061110.4103/mmj.mmj_548_17Open DOISearch in Google Scholar

Alt C, Bharwani N, Brunesch L, Danza FM, Derme M, El Sayed RF, et al. ESUR quick guide to female pelvis imaging 1.0. 2019: European Society of Urogenital Radiology. [cited 2020 May 15]. Available at: http://www.esur.org/fileadmin/content/2019/ESUR_2019_-_ESUR_Quick_Guide_to_Female_Pelvis_Imaging.pdfAltCBharwaniNBruneschLDanzaFMDermeMElSayed RFet alESUR quick guide to female pelvis imaging 1.02019European Society of Urogenital Radiologycited 2020 May 15Available athttp://www.esur.org/fileadmin/content/2019/ESUR_2019_-_ESUR_Quick_Guide_to_Female_Pelvis_Imaging.pdfSearch in Google Scholar

Koc Z, Erbay G, Ulusan S, Seydaoglu G, Aka-Bolat F. Optimization of b value in diffusion-weighted MRI for characterization of benign and malignant gynecological lesions. J Magn Reson Imaging 2012; 35: 650-9. doi: 10.1002/ jmri.22871KocZErbayGUlusanSSeydaogluGAka-BolatFOptimization of b value in diffusion-weighted MRI for characterization of benign and malignant gynecological lesionsJ Magn Reson Imaging201235650910.1002/jmri.22871Open DOISearch in Google Scholar

Foti PV, Attinà G, Spadola S, Caltabiano R, Farina R, Palmucci S, et al. MR imaging of ovarian masses: classification and differential diagnosis. Insights Imaging 2016; 7: 21-41. doi: 10.1007/s13244-015-0455-4FotiPVAttinàGSpadolaSCaltabianoRFarinaRPalmucciSet alMR imaging of ovarian masses: classification and differential diagnosisInsights Imaging20167214110.1007/s13244-015-0455-4Open DOISearch in Google Scholar

Meinhold-Heerlein I, Fotopoulou C, Harter P, Kurzeder C, Mustea A, Wimberger P, et al. The new WHO classification of ovarian, fallopian tube, and primary peritoneal cancer and its clinical implications. Arch Gynecol Obstet 2016; 293: 695-700. doi: 10.1007/s00404-016-4035-8Meinhold-HeerleinIFotopoulouCHarterPKurzederCMusteaAWimbergerPet alThe new WHO classification of ovarian, fallopian tube, and primary peritoneal cancer and its clinical implicationsArch Gynecol Obstet201629369570010.1007/s00404-016-4035-8Open DOISearch in Google Scholar

Outwater EK, Siegelman ES, Hunt JL. Ovarian teratomas: tumor types and imaging characteristics. Radiographics 2001; 21: 475-90. doi: 10.1148/radiographics.21.2.g01mr09475OutwaterEKSiegelmanESHuntJLOvarian teratomas: tumor types and imaging characteristicsRadiographics2001214759010.1148/radiographics.21.2.g01mr09475Open DOISearch in Google Scholar

Caruso PA, Marsh MR, Minkowitz S, Karten G. An intense clinicopathologic study of 305 teratomas of the ovary. Cancer 1971; 27: 343-8. doi: 10.1002/1097-0142(197102)27:2<343::aid-cncr2820270215>3.0.co;2-bCarusoPAMarshMRMinkowitzSKartenGAn intense clinicopathologic study of 305 teratomas of the ovaryCancer197127343810.1002/1097-0142(197102)27:2<343::aid-cncr2820270215>3.0.co;2-bOpen DOISearch in Google Scholar

Nakayama T, Yoshimitsu K, Irie H, Aibe H, Tajima T, Nishie A, et al. Diffusion-weighted echo-planar MR imaging and ADC mapping in the differential diagnosis of ovarian cystic masses: usefulness of detecting keratinoid substances in mature cystic teratomas. J Magn Reson Imaging 2005; 22: 271-8. doi: 10.1002/jmri.20369NakayamaTYoshimitsuKIrieHAibeHTajimaTNishieAet alDiffusion-weighted echo-planar MR imaging and ADC mapping in the differential diagnosis of ovarian cystic masses: usefulness of detecting keratinoid substances in mature cystic teratomasJ Magn Reson Imaging200522271810.1002/jmri.20369Open DOISearch in Google Scholar

Agostinho L, Horta M, Salvador JC, Cunha TM. Benign ovarian lesions with restricted diffusion. Radiol Bras 2019; 52: 106-11. doi: 10.1590/01003984.2018.0078AgostinhoLHortaMSalvadorJCCunhaTMBenign ovarian lesions with restricted diffusionRadiol Bras2019521061110.1590/01003984.2018.0078Open DOISearch in Google Scholar

Feuerlein S, Pauls S, Juchems MS, Stuber T, Hoffmann MH, Brambs HJ, et al. Pitfalls in abdominal diffusion-weighted imaging: how predictive is restricted water diffusion for malignancy. AJR Am J Roentgenol 2009; 193: 1070-6. doi: 10.2214/AJR.08.2093FeuerleinSPaulsSJuchemsMSStuberTHoffmannMHBrambsHJet alPitfalls in abdominal diffusion-weighted imaging: how predictive is restricted water diffusion for malignancyAJR Am J Roentgenol20091931070610.2214/AJR.08.209319770331Open DOISearch in Google Scholar

Dunn DP, Kelsey NR, Lee KS, Smith MP, Mortele KJ. Non-oncologic applications of diffusion-weighted imaging (DWI) in the genitourinary system. Abdom Imaging 2015; 40: 1645-54. doi: 10.1007/s00261-015-0471-3DunnDPKelseyNRLeeKSSmithMPMorteleKJNon-oncologic applications of diffusion-weighted imaging (DWI) in the genitourinary systemAbdom Imaging20154016455410.1007/s00261-015-0471-326109511Open DOISearch in Google Scholar

Duarte AL, Dias JL, Cunha TM. Pitfalls of diffusion-weighted imaging of the female pelvis. Radiol Bras 2018; 51: 37-44. doi: 10.1590/01003984.2016.0208DuarteALDiasJLCunhaTMPitfalls of diffusion-weighted imaging of the female pelvisRadiol Bras201851374410.1590/01003984.2016.0208Open DOISearch in Google Scholar

Takeuchi M, Matsuzaki K, Nishitani H. Diffusion-weighted magnetic resonance imaging of ovarian tumors: differentiation of benign and malignant solid components of ovarian masses. J Comput Assist Tomogr 2010; 34: 173-6. doi: 10.1097/RCT.0b013e3181c2f0a2TakeuchiMMatsuzakiKNishitaniHDiffusion-weighted magnetic resonance imaging of ovarian tumors: differentiation of benign and malignant solid components of ovarian massesJ Comput Assist Tomogr201034173610.1097/RCT.0b013e3181c2f0a220351498Open DOISearch in Google Scholar

Moyle PL, Kataoka MY, Nakai A, Takahata A, Reinhold C, Sala E. Nonovarian cystic lesions of the pelvis. Radiographics 2010; 30: 921-38. doi: 10.1148/rg.304095706MoylePLKataokaMYNakaiATakahataAReinholdCSalaENonovarian cystic lesions of the pelvisRadiographics2010309213810.1148/rg.30409570620631360Open DOISearch in Google Scholar

Kim MY, Rha SE, Oh SN, Jung SE, Lee YJ, Kim YS, et al. MR Imaging findings of hydrosalpinx: a comprehensive review. Radiographics 2009; 29: 495-507. doi: 10.1148/rg.292085070KimMYRhaSEOhSNJungSELeeYJKimYSet alMR Imaging findings of hydrosalpinx: a comprehensive reviewRadiographics20092949550710.1148/rg.29208507019325061Open DOISearch in Google Scholar

Laurent PE, Thomassin-Piana J, Jalaguier-Coudray A. Mucin-producing tumors of the ovary: MR imaging appearance Diagn Interv Imaging 2015; 96: 1125-32. doi: 10.1016/j.diii.2014.11.034LaurentPEThomassin-PianaJJalaguier-CoudrayAMucin-producing tumors of the ovary: MR imaging appearanceDiagn Interv Imaging20159611253210.1016/j.diii.2014.11.03425753545Open DOISearch in Google Scholar

Marko J, Marko KI, Pachigolla SL, Crothers BA, Mattu R, Wolfman DJ. Mucinous neoplasms of the ovary: radiologic-pathologic correlation Radiographics 2019; 39: 982-97. doi: 10.1148/rg.2019180221MarkoJMarkoKIPachigollaSLCrothersBAMattuRWolfmanDJMucinous neoplasms of the ovary: radiologic-pathologic correlationRadiographics2019399829710.1148/rg.2019180221667728331283462Open DOISearch in Google Scholar

Vargas HA, Barrett T, Sala E. MRI of ovarian masses J Magn Reson Imaging 2013; 37: 265-81. doi: 10.1002/jmri.23721VargasHABarrettTSalaEMRI of ovarian massesJ Magn Reson Imaging2013372658110.1002/jmri.2372123355430Open DOISearch in Google Scholar

Jung SE, Lee JM, Rha SE, Byun JY, Jung JI, Hahn ST. CT and MR imaging of ovarian tumors with emphasis on differential diagnosis Radiographics 2002; 22: 1305-25. doi: 10.1148/rg.226025033JungSELeeJMRhaSEByunJYJungJIHahnSTCT and MR imaging of ovarian tumors with emphasis on differential diagnosisRadiographics20022213052510.1148/rg.22602503312432104Open DOISearch in Google Scholar

Cho SM, Byun JY, Rha SE, Jung SE, Park GS, Kim BK, et al. CT and MRI findings of cystadenofibromas of the ovary. Eur Radiol 2004; 14: 798-804. doi: 10.1007/s00330-003-2060-zChoSMByunJYRhaSEJungSEParkGSKimBKet alCT and MRI findings of cystadenofibromas of the ovaryEur Radiol20041479880410.1007/s00330-003-2060-z14504904Open DOISearch in Google Scholar

Tang YZ, Liyanage S, Narayanan P, Sahdev A, Sohaib A, Singh N, et al. The MRI features of histologically proven ovarian cystadenofibromas-an assessment of the morphological and enhancement patterns. Eur Radiol 2013; 23: 48-56. doi: 10.1007/s00330-012-2568-1TangYZLiyanageSNarayananPSahdevASohaibASinghNet alThe MRI features of histologically proven ovarian cystadenofibromas-an assessment of the morphological and enhancement patternsEur Radiol201323485610.1007/s00330-012-2568-122814827Open DOISearch in Google Scholar

Siegelman ES, Outwater EK. Tissue characterization in the female pelvis by means of MR imaging. Radiology 1999; 212: 5-18. doi: 10.1148/radiology.212.1.r99jl455SiegelmanESOutwaterEKTissue characterization in the female pelvis by means of MR imagingRadiology199921251810.1148/radiology.212.1.r99jl45510405714Open DOISearch in Google Scholar

Woodward PJ, Sohaey R, Mezzetti TP Jr. Endometriosis: radiologic-pathologic correlation. Radiographics 2001; 21: 193-216; questionnaire 288-94. doi: 10.1148/radiographics.21.1.g01ja14193WoodwardPJSohaeyRMezzettiTP JrEndometriosis: radiologic-pathologic correlationRadiographics200121193216questionnaire 288-9410.1148/radiographics.21.1.g01ja1419311158655Open DOISearch in Google Scholar

Rockall A, Forstner R. Adnexal diseases. In: Hodler J, Kubik-Huch RA, von Schulthess GK, editors. Diseases of the abdomen and pelvis 2018-2021: diagnostic imaging. Cham (CH): IDKD Book; 2018. p. 75-84.RockallAForstnerRAdnexal diseasesHodlerJKubik-HuchRAvon SchulthessGKDiseases of the abdomen and pelvis 2018-2021: diagnostic imagingCham (CH)IDKD Book2018758410.1007/978-3-319-75019-4_831314383Search in Google Scholar

Siegelman ES, Oliver ER. MR imaging of endometriosis: ten imaging pearls. Radiographics 2012; 32: 1675-91. doi: 10.1148/rg.326125518SiegelmanESOliverERMR imaging of endometriosis: ten imaging pearlsRadiographics20123216759110.1148/rg.32612551823065164Open DOISearch in Google Scholar

Imaoka I, Wada A, Kaji Y, Hayashi T, Hayashi M, Matsuo M, et al. Developing an MR imaging strategy for diagnosis of ovarian masses. Radiographics 2006; 26: 1431-48. doi: 10.1148/rg.265045206ImaokaIWadaAKajiYHayashiTHayashiMMatsuoMet alDeveloping an MR imaging strategy for diagnosis of ovarian massesRadiographics20062614314810.1148/rg.26504520616973774Open DOISearch in Google Scholar

Zhang H, Zhang GF, He ZY, Li ZY, Zhang GX. Prospective evaluation of 3T MRI findings for primary adnexal lesions and comparison with the final histological diagnosis. Arch Gynecol Obstet 2014; 289: 357-64. doi: 10.1007/s00404-013-2990-xZhangHZhangGFHeZYLiZYZhangGXProspective evaluation of 3T MRI findings for primary adnexal lesions and comparison with the final histological diagnosisArch Gynecol Obstet20142893576410.1007/s00404-013-2990-x23934242Open DOISearch in Google Scholar

Funt SA, Hricak H. Ovarian malignancies. Top Magn Reson Imaging 2003; 14: 329-37. doi: 10.1097/00002142-200308000-00005FuntSAHricakHOvarian malignanciesTop Magn Reson Imaging2003143293710.1097/00002142-200308000-0000514578777Open DOISearch in Google Scholar

Hussain SM, Outwater EK, Siegelman ES. MR imaging features of pelvic mucinous carcinomas. Eur Radiol 2000; 10: 885-91. doi: 10.1007/s003300051029HussainSMOutwaterEKSiegelmanESMR imaging features of pelvic mucinous carcinomasEur Radiol2000108859110.1007/s00330005102910879695Open DOISearch in Google Scholar

Hann LE, Lui DM, Shi W, Bach AM, Selland DL, Castiel M. Adnexal masses in women with breast cancer: US findings with clinical and histopathologic correlation Radiology 2000; 216: 242-7. doi: 10.1148/ radiology.216.1.r00jl15242HannLELuiDMShiWBachAMSellandDLCastielMAdnexal masses in women with breast cancer: US findings with clinical and histopathologic correlationRadiology2000216242710.1148/radiology.216.1.r00jl15242Open DOISearch in Google Scholar

Outwater EK, Siegelman ES, Kim B, Chiowanich P, Blasbalg R, Kilger A. Ovarian Brenner tumors: MR imaging characteristics. Magn Reson Imaging 1998; 16: 1147-53. doi: 10.1016/s0730-725x(98)00136-2OutwaterEKSiegelmanESKimBChiowanichPBlasbalgRKilgerAOvarian Brenner tumors: MR imaging characteristicsMagn Reson Imaging19981611475310.1016/s0730-725x(98)00136-2Open DOISearch in Google Scholar

Yamashita Y, Hatanaka Y, Torashima M, Takahashi M, Miyazaki K, Okamura H. Characterization of sonographically indeterminate ovarian tumors with MR imaging. A logistic regression analysis. Acta Radiol 1997; 38: 572-7. doi: 10.1080/02841859709174389YamashitaYHatanakaYTorashimaMTakahashiMMiyazakiKOkamuraHCharacterization of sonographically indeterminate ovarian tumors with MR imaging. A logistic regression analysisActa Radiol199738572710.1080/028418597091743899240680Open DOISearch in Google Scholar

Bent CL, Sahdev A, Rockall AG, Singh N, Sohaib SA, Reznek RH. MRI appearances of borderline ovarian tumours Clin Radiol 2009; 64: 430-8. doi: 10.1016/j.crad.2008.09.011BentCLSahdevARockallAGSinghNSohaibSAReznekRHMRI appearances of borderline ovarian tumoursClin Radiol200964430810.1016/j.crad.2008.09.01119264189Open DOISearch in Google Scholar

deSouza NM, O’Neill R, McIndoe GA, Dina R, Soutter WP. Borderline tumors of the ovary: CT and MRI features and tumor markers in differentiation from stage I disease. AJR Am J Roentgenol 2005; 184: 999-1003. doi: 10.2214/ ajr.184.3.01840999deSouzaNMO’NeillRMcIndoeGADinaRSoutterWPBorderline tumors of the ovary: CT and MRI features and tumor markers in differentiation from stage I diseaseAJR Am J Roentgenol2005184999100310.2214/ajr.184.3.0184099915728632Open DOISearch in Google Scholar

Maggino T, Gadducci A, D’Addario V, Pecorelli S, Lissoni A, Stella M, et al., Prospective multicenter study on CA 125 in postmenopausal pelvic masses. Gynecol Oncol 1994; 54: 117-23. doi: 10.1006/gyno.1994.1179MagginoTGadducciAD’AddarioVPecorelliSLissoniAStellaMet alProspective multicenter study on CA 125 in postmenopausal pelvic massesGynecol Oncol1994541172310.1006/gyno.1994.11798063233Open DOISearch in Google Scholar

Zhang H, Zhang GF, He ZY, Li ZY, Zhu M, Zhang GX. Evaluation of primary ad-nexal masses by 3T MRI: categorization with conventional MR imaging and diffusion-weighted imaging. J Ovarian Res 2012; 5: 33. doi: 10.1186/1757-2215-5-33ZhangHZhangGFHeZYLiZYZhuMZhangGXEvaluation of primary ad-nexal masses by 3T MRI: categorization with conventional MR imaging and diffusion-weighted imagingJ Ovarian Res201253310.1186/1757-2215-5-33357631923148860Open DOISearch in Google Scholar

Recommended articles from Trend MD

Plan your remote conference with Sciendo