Amy Salinas MD, Abstract Co-Author: Nothing to Disclose

Liina Poder MD, Abstract Co-Author: Nothing to Disclose

Joseph Stengel DO, Abstract Co-Author: Nothing to Disclose

Seerat Aziz MD, Abstract Co-Author: Nothing to Disclose

Fergus V. Coakley MD, Abstract Co-Author: Nothing to Disclose

Aliya Qayyum MD, Presenter: Spouse, Employee, Koninklijke Philips Electronics NV

To determine the incremental value of MR imaging when performed in addition to ultrasound in patients with suspected placenta accreta, using updated diagnostic criteria.

We retrospectively identified 15 patients who underwent pelvic MR imaging after ultrasound for evaluation of suspected placenta accreta from January 1998 to December 2007. The MR imaging and ultrasound studies were independently reviewed by 3 readers who classified the likelihood of placenta accreta. All available clinical and medical records were reviewed to determine patient history and outcome. Three independent and experienced readers scored a total of 5 ultrasound and 5 MR features of the placenta as well as an overall impression. Sensitivity, specificity, positive and negative predictive values were calculated for each modality.

Seven of the fifteen patients had follow-up clinical and pathologic data. Four of the patients had confirmed placenta accreta and 3 were negative. The sensitivity, specificity, positive and negative predictive values for diagnosis of placenta accreta with ultrasound were 0.90, 0.56, 0.69, 0.83, respectively. The sensitivity, specificity, positive and negative predictive values for diagnosis of placenta accreta with MR imaging were 0.92, 0.57, 0.79, 0.80, respectively. There was no statistical difference in the diagnostic scores and overall impression as to the likelihood of placenta accreta between the 2 modalities. In particular, newer criteria such as dark placental bands on MR imaging did not correlate well with the overall impression on either modality.

 Even using updated diagnostic criteria, MR imaging does not appear to be of clear incremental diagnostic value to ultrasound in the diagnosis of placenta accreta.

Pending further research, MR imaging should be regarded as investigational when performed for the diagnosis of placenta accreta.

Salinas, A, Poder, L, Stengel, J, Aziz, S, Coakley, F, Qayyum, A, Ultrasound of Suspected Placenta Accreta: Incremental Value of MR Imaging Using Updated Diagnostic Criteria.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6022019.html