Between August 2012 and November 2012 12 patients affected by hystologically proved EC were enrolled in our prospective study.
MR examination was performed on a 1,5T scanner (Symphony,
Siemens) equipped with high-performing gradients (amplitude 30 mT/m),
with patient in supine position; before exam beginning,
20 mg of N-butile-scopolamine were injected i.v.
to reduce bowel movements artifacts.
Then we started with TSE T2-weighted sequences on multiple planes (FOV:220X220,slice thickness:4mm,effective matrix:384x75,
FA:180°,
TR:4400,
TE:104 both for sagittal and coronal planes; slice thickness:3mm,
effective matrix:320x75,
FA:180°,
FOV:280x280,
TR:5452,
TE:103 for axial oblique plane),
TSE T1-weighted on axial plane,
with and without fat saturation; diffusion weighted images were obtained on axial oblique,
coronal and sagittal planes with b values of 50,
400 and 800 s/mm2 (slice thickness:4mm,effective matrix192x192,
FOV:340x340,
TR:5500,
TE:85 both for sagittal and coronal planes; slice thickness:3mm,
effective matrix:192x192,
FOV:304x304,
TR:4600,
TE:84 for axial oblique plane)
Then ADC maps were generated from isotropic DW images,
by calculating the slope of logarithmic decay curve for signal intensity against b value with the use of a software.
Tumors were defined as lesions of heterogeneous intermediate signal intensity relative to the hyperintense normal endometrium and mildly hyperintense signal intensity relative to the normal myometrium on T2-weighted images; on high b value DW images tumors showed higher signal intensity than the adjacent myometrium and hypointense areas on the ADC map referring to the normal myometrium.
The depth of myometrial invasion was calculated both on TSE T2-weighted sequences (Figures 1-2-3) and on ADC maps on axial oblique,
sagittal and coronal planes (Figures 4-5).
It was defined as the distance between inner myometrial interface and deepest myometrial invasion point.
The myometrial invasion ratio was invasion depth divided by myometrial thickness,
defined as <50% vs >50%,
according with FIGO new staging.
The standard of reference were the hystological results.
Cases with imaging myometrial involvement more or equal than 50% were considered as true positive (TP) and false positive(FP); true negative (TN) and false negative (FN) cases were those with imaging myometrial invasion less than 50%.
Diagnostic performance of both T2W and DWI sequences in the assessment of myometrial invasion were evaluated,
considering sensibility,
specificity,
positive and negative predictive value and diagnostic accuracy for each one,
with a significative statistical correlation of p value <0,05.