Accuracy and Interobserver Reliability of Magnetic Resonance Imaging for Placenta Accreta Spectrum Disorders

Author(s):  
Brett D. Einerson ◽  
Christina E. Rodriguez ◽  
Robert M. Silver ◽  
Meghan A. Donnelly ◽  
Anne M. Kennedy ◽  
...  

Abstract Objective This study aims to define the accuracy, predictive value, and interobserver reliability of magnetic resonance imaging (MRI) in the diagnosis of placenta accreta spectrum (PAS) disorders. Study Design Two experienced radiologists independently interpreted the MRI studies of patients with possible PAS from two referral centers. Radiologists were blinded to sonographic and clinical information. We calculated diagnostic testing characteristics and kappa statistics of interobserver reliability for MRI findings of PAS. Results Sixty-eight MRI cases were evaluated. Confirmed PAS and severe PAS were present in 44 (65%) and 20 (29%) cases. For the diagnosis of any PAS, MRI had a sensitivity 66%, specificity 71%, positive predictive value (PPV) 81%, negative predictive value (NPV) 53%, and accuracy 68%. For the diagnosis of severe PAS (percreta), MRI had a sensitivity 85%, specificity 79%, PPV 63%, NPV 93%, and accuracy 81%. The accuracy of individual signs of PAS was lower (44–65%). Interobserver agreement was almost perfect for previa; substantial for myometrial interruptions, PAS, severe PAS, and placental bulging/balling; and moderate to slight for other signs of PAS. Conclusion Although the interobserver reliability of MRI for a diagnosis of PAS is substantial, the accuracy and predictive value are modest and lower than previously reported.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Cecilia Cavalli ◽  
Claudia Maggi ◽  
Sebastiana Gambarini ◽  
Anna Fichera ◽  
Amerigo Santoro ◽  
...  

Abstract Objectives We aimed to assess the performance of ultrasound (US) and magnetic resonance imaging (MRI) signs for antenatal detection of placenta accreta spectrum (PAS) disorders in women with placenta previa (placental edge ≤2 cm from the internal uterine orifice, ≥260/7 weeks’ gestation) with and without a history of previous Caesarean section. Methods Single center prospective observational study. US suspicion of PAS was raised in the presence of obliteration of the hypoechoic space between uterus and placenta, interruption of the hyperechoic uterine-bladder interface and/or turbulent placental lacunae on color Doppler. All MRI studies were blindly evaluated by a single operator. PAS was defined as clinically significant when histopathological diagnosis was associated with at least one of: intrauterine balloon placement, compressive uterine sutures, peripartum hysterectomy, uterine or hypogastric artery ligature, uterine artery embolization. Results A total of 39 women were included: 7/39 had clinically significant PAS. There were 6/18 cases of PAS with anterior placenta: hypoechoic space interruption and placental lacunae were the most sensitive sonographic signs (83%), while abnormal hyperechoic interface was the most specific (83%). On MRI, focal myometrial interruption and T2 intraplacental dark bands showed the best sensitivity (83%), bladder tenting had the best specificity (100%). 1/21 women with posterior placenta had PAS. There was substantial agreement between US and MRI in patients with anterior placenta (κ=0.78). Conclusions US and MRI agreement in antenatal diagnosis of clinically significant PAS was maximal in high-risk women. Placental lacunae on ultrasound scan and T2 intraplacental hypointense bands on MRI should trigger the suspicion of PAS.


Author(s):  
Elisa Lopes ◽  
Francisco Feitosa ◽  
Antonio Brazil ◽  
José de Castro ◽  
Jesus da Costa ◽  
...  

Objective To assess and compare the sensitivity and specificity of ultrasonography and magnetic resonance imaging in the diagnosis of placenta accreta in patients with placenta previa. Methods This retrospective cohort study included 37 women, and was conducted between January 2013 and October 2015; 16 out of the 37 women suffered from placenta accreta. Histopathology was considered the gold standard for the diagnosis of placenta accreta; in its absence, a description of the intraoperative findings was used. The associations among the variables were investigated using the Pearson chi-squared test and the Mann-Whitney U-test. Results The mean age of the patients was 31.8 ± 7.3 years, the mean number of pregnancies was 2.8 ± 1.1, the mean number of births was 1.4 ± 0.7, and the mean number of previous cesarean sections was 1.2 ± 0.8. Patients with placenta accreta had a higher frequency of history of cesarean section than those without it (63.6% versus 36.4% respectively; p < 0.001). The mean gestational age at birth among women diagnosed with placenta previa accreta was 35.4 ± 1.1 weeks. The mean birth weight was 2,635.9 ± 374.1 g. The sensitivity of the ultrasound was 87.5%, with a positive predictive value (PPV) of 65.1%, and a negative predictive value (NPV) of 75.0%. The sensitivity of the magnetic resonance imaging was 92.9%, with a PPV of 76.5%, and a NPV of 75.0%. The kappa coefficient of agreement between the 2 tests was 0.69 (95% confidence interval [95%CI]: (0.26–1.00). Conclusion The ultrasound and the magnetic resonance imaging showed similar sensitivity and specificity for the diagnosis of placenta accreta.


2019 ◽  
Vol 1 ◽  
pp. 97-100
Author(s):  
Vijinder Arora ◽  
Sonali Malik ◽  
Kunwarpal Singh

Objective: The objective of our study was to determine the role of diffusion-weighted (DW) magnetic resonance imaging (MRI) in diagnosing and differentiating between complete and partial anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears and to compare it with conventional MRI sequences. Materials and Methods: We conducted a prospective study for a period of 2 years from October 2017 to October 2019 on 30 patients with clinically suspected ACL/PCL injuries of the knee. MRI of the knee joint was performed using conventional, and DW sequences and the findings on both the sequences were assessed independently and compared with the intraoperative or follow-up MRI findings. Results: As per operative and follow-up MRI findings, the sensitivity and specificity of conventional MRI were 60% and 33.33% with a positive and negative predictive value of 47.37% and 45.45%, respectively. On the other hand, the sensitivity and specificity of DW MRI were 70.00% and 33.33% with a positive and negative predictive value of 51.22% and 52.13%, respectively. P = 0.417 was statistically not significant. Conclusion: According to our study, adding DW sequence to conventional MR sequences yielded comparable results in diagnosis and differentiation between complete and partial ACL and PCL tears.


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