2D and 3D MR imaging in the assessment of Fallopian tube features

Transcription

1 2D and 3D MR imaging in the assessment of Fallopian tube features Poster No.: C-1292 Congress: ECR 2010 Type: Topic: Scientific Exhibit Genitourinary Authors: J. Takahama, S. Kitano, N. Marugami, A. Takahashi, S. Miura, M. Takewa, T. Itoh, K. Kichikawa; Kashihara city, Nara/JP Keywords: Fallopian tube, MRI, 3D images Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 10

2 Purpose Introduction Though the dilated fallopian tubes can be easily detected on MRI because of its characteristic features, normal and not dilated fallopian tubes are too fine and torturous structures to detect in ordinal two-dimensional (2D) MR images because of its limit of resolution. Current MRI technique can provide more detailed information on the anatomy and pathology using three-dimensional (3D) images. 3D T2 weighted images (sampling perfection with application optimized contrasts using different flip angle evolutions=space) sequences and high resolution 3D gradient-echo (volumetric interpolated breath-hold examination=vibe) data allows high-quality planar images to be generated in any desired directions by means of multiplanar reconstruction (MPR). We herein report our retrospective comparison in clinical female pelvic images with regard to comparison the detectability of fallopian tubes between conventional 2D-T2 weighted images, 3D SPACE and VIBE. Purpose To demonstrate the diagnostic efficacy of 2D-T2 weighted images, 3D-T2 weighted images (SPACE) and 3D Dynamic contrast enhanced FS-T1WI (VIBE) for determining tubal features. Methods and Materials Patients The study included continuous 106 female patients that obtained pelvic MR images in our institute from January 2009 to June The twenty-seven patients were excluded due to the insufficient examination or post bilateral adnexal resection. Two patients who had undergone unilateral adnexal resection were included in this study. We analyzed retrospectively 79 patients with 156 adnexae (mean age, 53.1 years; age range, years). Pelvic MRI was performed for uterine leiomyoma (n=16), corpus cancer (n=9), cervical cancer (n=11), sarcoma (n=2), benign ovarian mass (n=9), malignant ovarian mass (n=8), endometriosis (n=9), vaginal melanoma (n=1) other benign condition (n=11), and normal in genital organ (n=3). Seventy-six patients with 150 adnexae underwent gadorinium enhanced MRI. MRI technique Page 2 of 10

3 We performed female pelvic MR examination on a commercially available 1.5T system (Magnetom Avant, Siemens Medical Solutions, Erlangen, Germany), employing a 4 channel SENSE body coil. We analyzed conventional 2D-T2 weighted images in axial and sagittal plane (TR/TE=4000/76, SENSE factor=1, Slice thickness=3mm, Matrix= 320 x 320), 3D- T2 weighted images (SPACE:TR/TE=2500/138 SENSE factor=2, Restore(+), Slice thickness=1mm, Matrix= 256x258) and 3D-Dynamic contrast enhanced FS-T1WI (VIBE: SPACE:TR/TE=4.3/1.49 FA=12, Slice thickness=1mm, Matrix= 256x258). Data Analysis: Qualitative Analysis A total of 156 sets, 2D-T2 weighted images and 3D-T2 weighted images, and also 150 sets, additional 3D-Dynamic contrast enhanced FS-T1 weighted images were randomly and independently evaluated on a commercially available workstation (Siemens Medical Solutions) by two independent reviewers (7 and 15 years of experience) blinded to patient. For the 3D data sets, both source images and MPR were reviewed. The fallopian tubes arise from the medial end of the upper lateral margin of the uterus and extend close to the ipsilateral ovary. In the reproductive age, the fallopian tubes are approximately 9-11cm long and 1-4mm wide in luminal diameter. For the fallopian tubes lie in a peritoneal fold along the superior margin of the broad ligament, they usually parallel to the utero-ovarian arterial anastomosis vessels suited in the broad ligament(1, 2). In addition, the round ligaments extend from the end of the upper lateral margin of the uterus and can be the help for detect the isthmus of the fallopian tube. For the normal fallopian tubes are usually collapsed and difficult to detect as tubal structure, we define normal fallopian tube as the lineal soft tissue structure arise from the uterus close to the round ligament and extend along to the utero-ovarian anastomosis vessels. The confidence level in determining the presence of the fallopian tube anatomy and pathological changes was graded as 1, nondiagnostic; 2, difficult to determine, low confidence; 3. some difficulty, moderate confidence; 4, little difficulty, high confidence. All dilated fallopian tubes were documented and measured the maximal diameter. We also documented not pathological, normal fallopian tubes that contains a little fluid and measured its diameter. Images for this section: Page 3 of 10

4 Fig. 1 Page 4 of 10

5 Results Results Overview of the qualitative values is shown in Table 1. Both 3D-T2 weighted images and 3D-Dynamic contrast enhanced FS-T1 images had more 4 (high-confidence) qualitative scores than the 2D-T2 weighted images. Otherwise, non-diagnostic materials are only estimated in 3D images. Remarkable dilated fallopian tubes were observed in 4 adnexae. The diameter was over 5mm in all cases (range 5-18mm). In both 2D- and 3D-images, the dilated fallopian tubes were detected with high confidence revel. Tubal structure contains small amount of fluid can be detected in 7 adnexae. 3D- T2 weighted images and 3D-Dynamic contrast enhanced FS-T1WI could detect these normal fallopian tubes. Though the confident score showed relative high on 3D-T2 weighted, we could not detect of no ovarian tubes on 2D-T2 weighted images in these patients. Images for this section: Page 5 of 10

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9 Conclusion Discussion MRI is useful tool for diagnosis of gynecologic lesions and now applied for many gynecological patients. Uterine and ovarian lesions had been reported in many papers about its anatomical and pathological images. Though MR images of dilated fallopian tube (hydrosalpinx, hematosalpinx, and pyosalpinx) were already reported in papers, the normal non-dilated fallopian tubes are not yet discussed enough besides salpingography(3-7). The long and torturous shape of the fallopian tube was difficult to determine in conventional MR images. 3D images, which enable to observe any oblique images using MPR, are now available on 1.5T MRI. Though SPACE was developed to reduce the flip angle or use a variable flip angle to limit the SAR at 3.0T-MRI, SPACE also can be used for 3D-T2 weighted images at 1.5T. SPACE magnetic resonance cholangiopancreatography was verified superior to conventional 3D TSE MRCP at 1.5T as a result of shortening of echo spacing. 3D-VIBE is also available at 1.5T and high spatial resolution. Though the normal fallopian tube is difficult to recognize because of its torturous collapsed shape, we defined it as the lineal soft tissue structure arise from the uterus close to the round ligament and extend along to the utero-ovarian anastomosis vessels. Using this definition, we could find the structure with confidence in 56% on SPACE, 62% on VIBE besides 40% on 2D-T2Wi. Comparing the conventional 2D images, 3D images make it easy to recognize the cord like structure. 3D-VIBE is better than 3D-T2Wi because contrast enhanced vessels are suitable to find the utero-ovarian anastomosis vessels. Though the 3D images have better confidence revel to find the fallopian tubes, nondiagnostic patients were observed in each sequence. In these cases, MR scan range is limited by enlarged uterus or large pelvic lesions. Dilated fallopian tubes (over 5mm) are observed in all images and no significant difference in subjective image quality. This result may lead that 3D-images have no advantage for diagnosis of tubal lesions comparing with ordinal imaging technique. One of reviewed patients in this study was proved as advanced tubal cancer, showed very typical dilated tubal findings. Though it was common findings, dilated continuous tubal feature was clear in 3D images and the confidence of diagnosis is higher than 2D images. Detection and recognition of normal fallopian tube is also important for detect atrophic ovary, or fallopian tubal cancer that sometimes detected as only solid mass without any dilated fallopian tubes. We believe this imaging may help clinical diagnosis. We also have limitation in this study. It is difficult to get all histopathological proof and the definition of the tube may depict other structure of pelvic lesion. Page 9 of 10

10 CONCLUSION 2D and 3D MRI are accurate methods for evaluation of dilated tube over 4mm diameter. 3D MRI may also improve detectability of minite fluid filled tube. References 1. Anderson M, Robboy S, Russel P. Pathology of the female reproductive tract. In: Robboy S, Anderson M, Russell P, eds. London, England: Churchill Livingstone, 2002; Wheeler JE. Pathology of fallopian tube. In: Blaunstein A, ed. Blaunstein's pathology of the female genital tract. 2nd ed. ed. New York, NY: Springer-Verlag, 1984; Gougoutas CA, Siegelman ES, Hunt J, Outwater EK. Pelvic endometriosis: various manifestations and MR imaging findings. AJR Am J Roentgenol 2000; 175: Ha HK, Lim GY, Cha ES, et al. MR imaging of tubo-ovarian abscess. Acta Radiol 1995; 36: Kawakami S, Togashi K, Kimura I, et al. Primary malignant tumor of the fallopian tube: appearance at CT and MR imaging. Radiology 1993; 186: Kim SH, Yang DM, Kim KA. Unusual causes of tubo-ovarian abscess: CT and MR imaging findings. Radiographics 2004; 24: Tukeva TA, Aronen HJ, Karjalainen PT, Molander P, Paavonen T, Paavonen J. MR imaging in pelvic inflammatory disease: comparison with laparoscopy and US. Radiology 1999; 210: Personal Information Page 10 of 10