Figure - available from: BMC Pregnancy and Childbirth
This content is subject to copyright. Terms and conditions apply.
PAS disorders in a 33-year-old woman with prior cesarean delivery and placenta previa. (a)T2WI(T2 weighted imaging) showed abnormal vascularization of placental bed and abnormal intraplacental vascularity. The accreta lesion was generally iso- to hyperintense on DWI (b), heterogeneously hyperintense on ADC map (c) and hyperintense on eADC map (d) (white arrow). On IVIM(intravoxel incoherent motion) images, the lesions appeared heterogeneously hyperintense on D map (e), heterogeneous on D* map (f) and hypo- to isointense with some areas of hyperintense on f map (g) (white arrow). On DKI (diffusion kurtosis imaging) images, the lesions appeared iso- to hyperintense on MD map (h) and hypointense on MK map (i) (white arrow)
Source publication
Background
To investigate the diagnostic value of monoexponential, biexponential, and diffusion kurtosis MR imaging (MRI) in differentiating placenta accreta spectrum (PAS) disorders.
Methods
A total of 65 patients with PAS disorders and 27 patients with normal placentas undergoing conventional DWI, IVIM, and DKI were retrospectively reviewed. The...
Similar publications
Background
To evaluate and compare the potential performance of various diffusion parameters obtained from mono-exponential model (MEM)-, bi-exponential model (BEM)-, and stretched exponential model (SEM)-based diffusion-weighted imaging (DWI) in grading of esophageal squamous carcinoma (ESC).
Methods
Eighty-two patients with pathologically confir...
Citations
... Intravoxel incoherent motion (IVIM) is a bi-exponential DWI model that separates microvascular perfusion from water molecular diffusion within the tissue [18,19], while Diffusion kurtosis imaging (DKI) is a non-Gaussian DWI model that allows accurate quanti cation of tissue heterogeneity and cellularity [20,21]. Our previous studies showed functional MRI can be used to differentiate PAS disorders [22,23]. However, the diagnostic performance of MRI features ad DWI parameters has not been compared and whether DWI parameters can help improve the diagnosis of invasive placentas has not be determined. ...
Introduction: To investigate if functional MRI can add additional diagnostic value in distinguishing invasive placentas in patients with placenta previa.
Methods: A total of 53 patients with invasive placentas and 20 patients with noninvasive placentas were retrospectively enrolled. DWI parameters were measured by volumetric analysis and MRI images were reviewed,respectively. The differences of DWI parameters and MRI features were compared. The receiver operating characteristic (ROC) curve and logistic regression analysis were used to assess the ability of different diffusion parameters and MRI features for distinguishing invasive placentas.
Results: Comparisons between patients with invasive and noninvasive placentas demonstrated D mean and D* min were significantly higher while ADC max and D max were significantly lower in patients with invasive placentas (p < 0.05). T2 dark bands, placental heterogeneity, abnormal intraplacental vascularity and placental bulge were associated with invasive placentas (p < 0.05). Multivariate analysis demonstrated that D max was an independent risk factor for invasive placentas. The AUC was 0.79 with sensitivity, specificity, and accuracy of 70%, 87%, and 78.5%, respectively.
Discussion: D max helps distinguish invasive placentas in patients with placenta previa.
... Diffusion kurtosis imaging (DKI) is another DWI model utilized in the quantification of the heterogeneity and cellularity of the tissue (17). Our previous studies employed these two DWI models to explore placental function in patients with PAS disorders; the ability of DWI parameters to predict PPH has not yet been ascertained (18,19). ...
Background
Placenta accreta spectrum (PAS) disorder encompasses a spectrum of pathologies, from placenta accreta to placenta percreta, which is usually associated with postpartum hemorrhage (PPH).
Methods
This cross-sectional study enrolled 109 patients suspected of having PAS disorders based on previous ultrasound results or clinical risk factors from November 2018 to March 2022 in Sichuan Provincial People’s Hospital. Of the 109 patients, 34 had PPH and 75 did not have PPH. Magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI) was performed for each patient and the apparent diffusion coefficient (ADC) from DWI, perfusion fraction (f), pure diffusion coefficient (D), and pseudo-diffusion coefficient (D*) from IVIM, and mean diffusion kurtosis (MK) and mean diffusion coefficient (MD) from DKI were measured and compared. The correlation between the DWI parameters and estimated blood loss (EBL) during surgery was identified using correlation analysis. The diagnostic performance for predicting PPH was compared between the two methods.
Results
The amount of bleeding during delivery was positively correlated with D [r=0.331, P<0.001, 95% confidence interval (CI): 0.170 to 0.477], D* (r=0.389, P<0.001, 95% CI: 0.207 to 0.527), f (r=0.222, P=0.02, 95% CI: 0.036 to 0.398), and MD (r=0.277, P=0.003, 95% CI: 0.108 to 0.439), but negatively correlated with MK (r=−0.280, P=0.003, 95% CI: −0.431 to −0.098). In predicting PPH, multivariate analyses showed the independent risk factors were placenta previa and D; the area under the curve (AUC) was 0.795 (95% CI: 0.711 to 0.878) when the two risk factors were combined together.
Conclusions
IVIM and DKI parameters are correlated with EBL. The combined use of placenta previa and D are helpful for predicting PPH in patients at high risk of PAS disorders.
Objectives:
To identify whether parameters measured from diffusion kurtosis and intravoxel incoherent motion help diagnose placenta percreta.
Methods:
We retrospectively enrolled 75 patients with PAS disorders including 13 patients with placenta percreta and 40 patients without PAS disorders. Each patients underwent diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI). The apparent diffusion coefficient (ADC), perfusion fraction (f), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), mean diffusion kurtosis (MK) and mean diffusion coefficient (MD) were measured by the volumetric analysis and compared. MRI features were also analyzed and compared. The receiver operating characteristic (ROC) curve and logistic regression analysis were used to evaluate the diagnostic efficiency of different diffusion parameters and MRI features for distinguishing placental percreta.
Results:
D* was an independent risk factor from DWI for predicting placenta percreta with sensitivity of 73% and specificity of 76%. Focal exophytic mass remained as independent risk factor from MRI features for predicting placenta percreta with sensitivity of 72.7% and specificity of 88.1%. When the two risk factors were combined together, the AUC was the highest, 0.880 (95% CI 0.8-0.96).
Conclusion:
D* and focal exophytic mass were associated with placenta percreta. A combination of the 2 risk factors can be used to predict placenta percreta.
Critical relevance statement:
A combination of D* and focal exophytic mass can be used to differentiate placenta percreta.
