Diffusion-weighted MR imaging for Diagnosis of Uterine Leiomyomas

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1 Diffusion-weighted MR imaging for Diagnosis of Uterine Leiomyomas Poster No.: C-0111 Congress: ECR 2015 Type: Scientific Exhibit Authors: A. Er 1, G. Pekindil 2, M. Gök 3, A. R. Kandiloglu 2, A. G. Tamay 2 ; Van/TR, Manisa/TR, Kars/TR Keywords: DOI: Genital / Reproductive system female, MR physics, MR-Diffusion/ Perfusion, MR, Imaging sequences, Molecular imaging, Outcomes analysis, Image verification, Pathology, Tissue characterisation /ecr2015/C-0111 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 11

2 Aims and objectives Uterine leiomyomas or fibroids are the most common pelvic tumors in women. The insidence of these tumors is 30%, in women over age 30 (1). As high resolution Magnetic Resonance equipment were introduced and commonly used, Magnetic Resonance Imaging (MRI) has been used as the first choice in pelvic region assessment with its superiority in soft tissue resolution and ability of obtaining multiplanar imaging (2). Additionaly in recent years, Diffusion Weighted Imaging (DWI) has also been used, to be able to assess pelvic region fast, and non-invasively (3). Although leiomyomas are easy to diagnose with their hypointensity in T2WI, at times they are difficult to differentiate from other malign uterine tumors, specifically from leiomyosarcomas. The ability to differentiate these tumors is rendered more difficult with atypical degenerated leimyoma forms. Knowing the Apparent Diffusion Coefficient (ADC) values with DWI for leiomyomas is thought to help differentiate them from other malign tumors (4,5). There are limited studies within the literature about this issue. The aim of our study is to determine ADC values with DWI of histopathologically proven leimyoma's of patients who for various reasons were operated on and obtained pelvic MRI's preoperatively. As our study did not include malign uterine tumors within the study group, we did not compare the ADC values of benign against malign uterine tumors. Methods and materials The study population included 50 women who had pelvic MRI with DWI for various gynecological diseases and were surgically treated [myomectomy (n:10 or hysterectomy (n:40)] at our institution. We retrospectively analysed MRI and DWI of all patients who had histopathological diagnoses after surgery. 10 patients whose leiomyomas were under 2cm in size and 2 patients whose images we were not able to obtain, were excluded from the study group. The final study population was 38 women aged years old with a mean age 43.78±8.39. The leiomyoma sizes ranged from 2cm to 18cm. The location included 53 intramural, 12 subserosal and 4 submucosal. In 19 patients (52.8%) there was only one, in 9 patients (25%) there were two, in 3 patients (8.3%) there were three, in 4 patients (11.1%) there were four and in 1 patient (2.8%) there were five leiomyomas, totaling 69 leiomyomas analysed by the study. According to postoperative histopathological diagnoses 78.3% (n:54) of these were typical leiomyoma, 14.5% (n:10) of these were cellular leiomyoma and 7.2% (n:5) of these were degenerated leiomyomas. Page 2 of 11

3 In the pelvic MRI, sagittal T2, axial T2, fat-suppressed axial T1, diffusion b 800 sequences were used. By forming ADC maps, ADC measurements were obtained by placing ROI over from the parts of the leiomyomas which were not cystic, calcific or hemorrhagic (3). Results In Diffusion-weighted MR imaging, %100 percent of cellular leiomyomas, %20 percent of degenerated leiomyomas and %5,6 percent of ordinary leiomyomas showed high SI. The mean ADC values of typical leiomyomas, degenerated leiomyomas and cellular leiomyomas are measured as 1.29 x10-3, 1.86 x10-3, 1.11 x10-3 respectively. There was a statistically meaningful difference between ADC values. There was also significant difference between ADC values of leiomyomas smaller then 8 cm and leiomyomas larger then 8 cm. Histopathological Number Minimum Maximum Mean Standart Diagnosis Deviation P value Typical 54 0,89 1,8 1,29 0,19 0,016 Degenerated5 1,67 2,04 1,86 0,17 0,016 Cellular 10 0,90 1,3 1,11 0,13 0,016 Myometrium17 1,52 1,85 1,64 0,09 0,016 Table 1: ADC values (b:800) of leiomyomas according to histopathological diagnosis and normal myometrium. Images for this section: Page 3 of 11

4 Fig. 1: ADC value distribution according to histopathology of leiomyomas (1:typical, 2:degenerated, 3: cellular) Page 4 of 11

5 Fig. 2: Patient#5, 45y/o female with typical intramural leiomyoma, hypointense in T2WI. Page 5 of 11

6 Fig. 3: Patient#5, 45y/o female with typical intramural leiomyoma, in DWI (b:800) leiomyoma is isointese with myometrium. Page 6 of 11

7 Fig. 4: Patient#5, 45y/o female with typical intramural leiomyoma, in ADC mapping (b:800) ADC value measured 1.26x10-3. Page 7 of 11

8 Fig. 5: Patient#7, 47y/o female with degenerated leiomyoma, in T2WI it is hyperintense. Page 8 of 11

9 Fig. 6: Patient#7, 47y/o female with degenerated leiomyoma, in DWI leiomyoma is isointense with myometrium. Page 9 of 11

10 Fig. 7: Patient#7, 47y/o female with degenerated leiomyoma, in ADC mapping ADC value was measured 2,04x10-3. Page 10 of 11

11 Conclusion The knowledge of typical characteristics of leiomyomas in diffusion weighted MR imaging is considered as a useful tool in differentiation between leiomyoma subtypes (typical, cellular, degenerated) and other malignant tumors such as uterine neoplasm and leiomyosarcoma. Personal information References 1. Wamsteker K, Emanuel MH, de Kruif JH. "Transcervical hysteroscopic resection of submucous fibroids for abnormal uterine bleeding: results regarding the degree of intramural extension." Obstet Gynecol 1993; 82: Edelman R, Zlatkin MB, Hesselink JR, "Clinical magnetic resonance imaging." 2nd edition. Philadepphia: WB Saunders Company, 1996; Whittaker CS, Coady A, Culver L, Rustin G, Padwick M, Padhani AR. "Diffusion-weighted MR imaging of female pelvic tumors: A pictorial review." RadioGraphics 2009;29: Tamai K, Koyama T, Saga T, Morisawa N, Mikami Y, Togashi K, "The utility of diffusion weighted MR imaging for differentiating uterine sarcomas from benign leiomyomas." Eur Radiol 2008, 18: Namimoto T, Awai K, Nakaura T, Yanaga Y, Hirai T, Yamashita Y. "Role of diffusion-weighted imaging in the diagnosis of gynecological diseases." EurRadiol 2009;19: Page 11 of 11