الفهرس 
ACKNOWLEDGEMENTOnly 14 pages are availabe for public view
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Abstract
Ovarian cancer has been a leading malignancy endangering women’s health with high rate of worldwide prevalence. It is well known as the silent killer as it is mostly presented late with vague nonspecific GIT symptoms. Optimum management depends upon accurate preoperative characterization and staging of the ovarian mass. Imaging modalities have advanced greatly in order to improve characterization of female pelvic masses.
More recently functional methods as MRI Perfusion and MR diffusion have been tested to improve the diagnostic confidence about 25% and 15%, respectively thus increase the accuracy of MRI imaging to 94.6%.
The aim of our study to demonstrate the role of MR perfusion in preoperative characterization of adnexal masses.
This is a prospective study conducted in Assiut university hospital including 32 patients presented with indeterminate adnexal lesions on US basis. Our selection criteria were presence of a solid component (vegetation’s, thick septa (≥ 3mm thickness, or soft tissue component within the adnexal mass of sufficient size ≥3mm) to draw a region of interest or Pure solid lesions. We excluded Patients with simple cystic adnexal lesions containing no solid part, lesions that had a solid component <3 mm in size as it was not possible to obtain meaningful post -processing data, pregnant women with ovarian cancer as there may be a risk from administration of contrast agent in these patients, women with impaired renal functions, those who underwent previous hysterectomy for any cause or patients with any general contraindication to MRI as presence of any paramagnetic substance as pacemakers.
The study group age ranged from ranged from 15 to 73 years with mean (44.41).
MR Perfusion technique based on DCE T1 weighted sequence is recently referred as Permeability MRI as it shows that factors related to tumor biological processes and neoangiogenesis are determinants in the contrast uptake dynamics in adnexal masses. In this study we performed rapid DCE imaging using GRE TIWI FAT SAT with temporal resolution of 14 sec for each phase. We performed 30 consecutive phase, each phase was 14 seconds with the whole sequence lasting for 7 minutes. The imaged stack should include part of the soft tissue inside the adnexal mass (i.e., solid portion, papillary projections, or thickened irregular septa) and the adjacent external myometrium in the optimal plane.
All patients underwent operative management. The result of MRI was correlated with histopathological findings.
Type 1 curve was tested to be 100% specific to benign cases. Type 3 curve was 76.5% sensitive and 60% specific in predicting malignancy. while type II curve showed significant overlap between benign and malignant tumors with no evident diagnostic performance .There was significant correlation between curve type and pathological diagnosis of the lesions (p=0.017)
In the current study, the most perfusion parameter that showed significant difference between benign vs. invasive lesion was WOR (wash out rate) (P=0.028).To our knowledge, no published literature demonstrated the role of WOR in discriminating between benign and malignant adnexal lesion.
In this study, we demonstrated that a lesion with a WOR ˃ 6.03 is likely to be malignant (PPV 93.3%).
WIR (Wash in Rate) showed high sensitivity (88.2%) but low Specivity (50%).Thus we can depend upon WIR in depicting malignant masses and correct our diagnosis by applying the cutoff of WOR to exclude the false positive cases so avoiding radical surgery in unnecessary patients especially in women in childbearing period aiming at preserving fertility.
Also, SImax (maximum absolute enhancement) showed relevant criterion for distinguishing invasive from non-invasive tumors as it represent the vascular density within the tumor. In our study it showed a 73.2% accuracy and PPV 81.2% in distinguishing benign and malignant tumours.