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العنوان
Role of diffusion weighted and perfusion weighted imaging in characterization of ovarian tumours /
المؤلف
Mohamed, Eman Sameh Hussein.
هيئة الاعداد
باحث / Eman Sameh Hussein Mohamed
مشرف / Randa Hussein Abdallah
مشرف / Nermeen Nasry Halim
مناقش / Eman Ahmed Fouad
تاريخ النشر
2018.
عدد الصفحات
139 P. :
اللغة
الإنجليزية
الدرجة
الدكتوراه
التخصص
الأشعة والطب النووي والتصوير
تاريخ الإجازة
1/1/2018
مكان الإجازة
جامعة عين شمس - كلية الطب - قسم الاشعة التشخيصية
الفهرس
Only 14 pages are availabe for public view

from 139

from 139

Abstract

Ovarian tumors; are the second most common gynecological tumor and is the fifth commonest tumor in women.
Although the final diagnosis of an ovarian tumor is based on the histological examination, it is preferred to preoperatively characterize and differentiate between benign, border line tumors and invasive ovarian cancers, in order to decide if surgery is required, and which type of surgery is appropriate. Thus, helping to avoid unnecessary surgery especially in postmenopausal women and help deciding for conservative surgery for young women wishing to preserve childbearing potential.
US is the first imaging modality that can be used for detection of adnexal mass lesions. CT also is used for detection of distant metastasis of the tumour however; it has limited capapbility of assessing local metastasis. However, more accurate lesion characterization is done through MRI. Conventional MRI provides soft tissue characterization based on different signal intensities and contrast uptake in post contrast images.
With the development of recent technologies, new functional MRI sequences are being used. Of these, is the diffusion weighted images (DWI) and dynamic contrast enhanced MRI (DCE-MRI). DWI is used in the abdomen and pelvis after it has been established as a useful functional imaging tool in neurologic applications for a number of years.
DWI depends on the fact that water molecules can diffuse freely in low cellular environment, while tissue hyper cellular environment restricts its movement, a phenomenon called ‛Brownian motion’. As a result, malignant ovarian tumors due to their hypercellular nature show diffusion restriction, unlike most benign tumors. So it implies a noninvasive technique which can be used especially if contrast intake is avoided as in pregnancy.
DCE- MRI depends on the leakage of contrast agent from capillaries into the extravascular extracellular space, thus allowing quantitative analysis which reflects the blood flow and the vascular permeability. Dynamic contrast-enhanced MR correlate with tumoral angiogenesis & can help distinguish benign, borderline, and invasive tumors.
Our study showed that addition of DWI as well as DCE-MRI to the conventional MRI increased the sensitivity, specificity and accuracy of the examination.
In conclusion, the combination of DWI and DCE to conventional MRI:
• Using a completely noninvasive technique with no radiation exposure
• It improves the specificity of MRI and thus increasing the radiologist’s confidence in image interpretation which will finally reflect on the patients’ outcome and prognosis.
• DWI might be an alternative for contrast administration especially for those where contrast intake is better avoided as during pregnancy.
Limitations:
• DWI and dynamic study interpretation should be in conjunction with other morphological criteria in conventional MRI sequences as there is some overlap in the results of diffusion regarding mature cystic teratomas.
Recommendations:
• Further study with large number of patients is recommended
• Patients with mature cystic teratomas better to be avoided on further similar studies as in these cases; DWI findings are misleading and can give false results.