Valeria Ninivaggi MD, Presenter: Nothing to Disclose

Anna Lia Valentini MD, Abstract Co-Author: Nothing to Disclose

Benedetta Gui MD, Abstract Co-Author: Nothing to Disclose

Maura Micco MD, Abstract Co-Author: Nothing to Disclose

Michela Giuliani, Abstract Co-Author: Nothing to Disclose

Lorenzo Bonomo MD, Abstract Co-Author: Nothing to Disclose

To compare magnetic resonance imaging (MRI) with operative delivery findings or histopathology in diagnosing placental adhesive disorders; to verify whether a combination of specific signs improves MRI accuracy.

Two Radiologist with expertise in gynecological imaging retrospectively reviewed 18 MRI of pregnant women with placenta previa examined in our Institution from April 2011 to April 2014 after inconclusive ultrasound evaluation for placental adhesive disorders. Radiologists worked independently, blinded to clinical history of patients. For each patient the presence or absence of MRI findings reported in literature in cases of placental disorders were assessed: intraplacental thick dark bands on T2w images, intraplacental abnormal vascularity, uterine bulging, myometrial thinning, focally interrupted myometrial border, heterogeneous intraplacental signal intensity, placental protrusion into internal os, tenting of the bladder and direct visualization of nearest tissues invasion. Interpretation discrepancies were resolved by consensus. A third radiologist investigated history of patients and correlated imaging data with the gold standard: histological specimen in case of hysterectomy (4/18) or difficult detachment with hemorrhage described in surgical report in case of conservative approach (3/18).

Each singular sign was investigated separately for sensitivity (SS) and specificity (SP): intraplacental thick dark bands on T2w images (SS 71%, SS 100%), intraplacental abnormal vascularity (SS 71%, SP 100%), myometrial thinning less than 5 mm (SS 100%, SP 18%), heterogeneous intra-placental signal intensity (SS 71%, SP 54%), uterine bulging (SS 57%, SP 90%), focal interruption (SS 0,57%, SP 100%), direct invasion (SS 42%, SS 100%) and tenting of bladder (SS 57%, SP 100 %). Protrusion into internal os was not detected. In our series combined evaluation of all imaging signs detected suggest deepest infiltration in patient who underwent hysterectomy (SS 75%; SP 100%).

MRI accuracy in diagnosis of placental adhesive disorders can be improved by taking into account the association of reported signs. However, is not possible on the basis of MRI assess the degree of myometrial involvement

The detection of specific MRI signs could typify patients with Placental abnormality to ensure the correct preoperative assessment and the appropriate treatment planning in a safer way.

Ninivaggi, V, Valentini, A, Gui, B, Micco, M, Giuliani, M, Bonomo, L, Association of MRI Signs in Diagnosis of Placenta Accreta: Preliminary Results.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045705.html