الفهرس 
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Abstract
MR imaging is used as a problem-solving tool for confusing ovarian
lesions, characterizing benign and malignant ovarian tumors; moreover, it
enables a specific diagnosis for certain pathologic types. For example,
MR imaging is well known to provide accurate information about
hemorrhage and fat.
MR imaging characteristics and clinical history may all help in
narrowing the differential diagnosis of female pelvic masses although the
final diagnosis is based on the histological examination.
Morphologic imaging features are used primarily for distinguishing
benign from malignant gynecologic masses and for evaluating potential
metastatic disease. Newer tools such as functional imaging with DWI are
becoming increasingly important in the evaluation of ovarian masses.
DWI is of interest for tumor detection, characterization, and response
to treatment. DWI depends on the fact that water molecules can diffuse
freely in low cellular environment, while tissue hypercellularity causes its
restriction, a phenomenon called ‛Brownian motion’. As a result,
malignant tumors due to its hypercellular nature show restricted diffusion,
unlike most benign tumors. So it implies a noninvasive technique which
can be used especially if contrast intake is avoided.
Our study included 30 patients with different ovarian lesions, 22
benign cases and 8 malignant cases proved by histopathology and
laparoscopy, and the mean age was 40.37 years.
Pelvi-abdominal pain was the most common complaint among
patients under study.
All of patients subjected to MRI pelvic assessment performed on 1.5T
MR imaging machine with pelvic phased-array coil.
The MRI protocol was T1 in axial plane, T2 in axial , coronal and
sagittal , T1 (post contrast for some cases) fat saturation in axial , coronal
and sagittal and diffusion weighted images. All cases MRI results were
compared with pathological or laparoscopic results.
For differentiation between benign and malignant ovarian lesions
most of benign ovarian lesions show facilitated diffusion (14 benign cases
in our study), except some benign lesions (for example in our study: one
hemorrhagic cyst case, one chocolate cyst case, one proteinaceous cyst
case and three tubo-ovarian abscess cases). While most of malignant
ovarian lesions show restricted diffusion and corresponding low values in
ADC maps (six malignant cases in our study) with ADC value ≥ [OR ≤ ]
1.16 × 10-3 mm2/s as a cutoff point differentiating between benign and
malignant ovarian lesions.
Five cases which were complex cystic and solid, two cases associated
with ascites and one case with papillary projections, seven cases of
mixed contents and six cases which had heterogeneous pattern of
enhancement proved to be malignant pathologically.
For differentiation between benign and malignant ovarian lesions by
MRI in comparison to histopathology and laparoscopy, the sensitivity,
specificity, PPV, NPV and accuracy of conventional MR imaging all
have increased from 87.5% , 86.4 , 70% , 95% , 86.7% respectively for
conventional MRI to 100% , 93.3% , 88.9% , 100% , 95% respectively
for diffusion MR imaging.