The role of three-dimensional MRI in the differentiation between angular pregnancy and interstitial pregnancy

Background

In clinical practice it is an ongoing challenge to distinguish between angular pregnancy and interstitial pregnancy. With the three-dimensional (3D) magnetic resonance imaging (MRI) being increasingly used, it is worth exploring its role in differentiating angular pregnancy from interstitial pregnancy. This study aims to investigate how 3D MRI can help reveal the differences between these two special pregnancies in the early diagnosis.

Methods

We reviewed and analyzed the 3D MRI images of 50 patients with interstitial pregnancy and 55 patients with angular pregnancy retrospectively. Imaging features were identified to compare these two special pregnancies, and the ROC (Receiver Operating Characteristic) analysis was conducted to assess the diagnostic performance.

Results

The significant differences of the 3D MRI imaging features between interstitial pregnancy and angular pregnancy were found in the outline of uterus cavity (p < 0.001), involvement of junctional zone (p < 0.001), the signal of surroundings (p = 0.005), the relationship with round ligament (p = 0.042), and the overlying myometrial thickness (p = 0.041). Furthermore, the multivariate logistic regression analysis identified a series of significant indicators for angular pregnancy, including the junctional zone involvement, being-surrounded by hyper/iso-intensity on 3D images, and the asymmetric outline of uterus cavity. Combining these three imaging features, the AUC (Area under the Curve) of ROC curve was 0.87 in distinguishing interstitial pregnancy from angular pregnancy.

Conclusions

This study suggests that 3D MRI can help distinguish angular pregnancy from interstitial pregnancy in clinical practice, with the advantages that conventional MRI or ultrasound does not have. Through the significant image features, 3D MRI plays an important role in improving the timing of diagnosis, avoiding unnecessary interventions, and preventing hemorrhage in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04470-z.

Adenomyosis and infertility: the role of the junctional zone

OBJECTIVE

Adenomyosis is a benign uterine disorder characterized by the invasion of the endometrium within the myometrium, starting from the junctional zone (JZ), the inner hormone dependent layer of the myometrium that plays an important role in sperm transport, implantation and placentation. The resulting histological abnormalities and functional defects may represent the pathogenic substrate for infertility and pregnancy complications. The objective of this paper is to review the literature to evaluate the correlation between inner myometrium alterations and infertility and to assess the role of JZ in the origin of adverse obstetric outcomes of both spontaneous and in vitro fertilization (IVF) pregnancies.

METHODS

we searched Pubmed for all original and review articles in the English language from January1962 until December 2019, using the MeSH terms of 'adenomyosis', 'junctional zone', combined with 'infertility', 'obstetrical outcomes', 'spontaneous conception', 'in vitro fertilization' and 'classification'. The review was divided into three sections to assess this pathogenic correlation, evaluating also the importance of classification of the disease.

RESULTS AND CONCLUSIONS

Absent or incomplete remodeling of the JZ can affect uterine peristalsis, alter vascular plasticity of the spiral arteries and activate inflammatory pathways, all related to adverse obstetric outcomes. Despite these observations, there is still limited evidence whether adenomyosis is a cause of infertility. However, it is reasonable to screen patients for adenomyosis, to consider pregnant women with diffuse adenomyosis at high risk of adverse obstetric outcomes, and to evaluate the importance of a noninvasive validated classification in the management of women with adenomyosis.

Upregulated microRNA let-7a accelerates apoptosis and inhibits proliferation in uterine junctional zone smooth muscle cells in adenomyosis under conditions of a normal activated hippo-YAP1 axis

BACKGROUND

Let-7a is a small non-coding RNA that has been found to take part in cell proliferation and apoptosis. The hippo-YAP1 axis, known as a tumour suppressor pathway, also plays an important role in cell proliferation and apoptosis. YAP1, TAZ, and phospho-YAP1 play key roles in actions of the hippo-YAP1 axis. Adenomyosis (ADS) is a proliferative disease leading to a large uterus in patients with prolonged illness. Abnormal proliferation of smooth muscle cells (SMCs) in the uterine endometrial-myometrial junctional zone (JZ) is an important reason for developing ADS. This study aimed to explore the expression levels of let-7a and components of the hippo-YAP1 axis in SMCs in the uterine endometrial-myometrial JZ in ADS and to explore the roles of let-7a and the hippo-YAP1 axis of JZ SMC proliferation and apoptosis in ADS.

METHODS

We collected JZ tissues for the primary culture of SMCs from 25 women diagnosed with ADS and 27 women without ADS. We used quantitative real-time polymerase chain reaction and western blotting to measure the mRNA and protein expression levels of let-7a, YAP1, TAZ, and phospho-YAP1 in ADS JZ SMCs. A CCK-8 assay and flow cytometry analysis of apoptosis were utilized to test the proliferation and apoptosis of JZ SMCs. The let-7a overexpression lentiviral vector GV280 was used to increase the expression level of let-7a. We added verteporfin to block the phosphorylation of components of the hippo-YAP1 axis.

RESULTS

We found that the let-7a level was decreased, while the YAP1 and TAZ levels were increased in ADS JZ SMCs. Upregulated let-7a affected the expression levels of components of the hippo-YAP1 axis, accelerated apoptosis, and inhibited proliferation in JZ SMCs. Furthermore, accumulated YAP1 led to increasing proliferation of JZ SMCs after verteporfin treatment to block the phosphorylation of components of the hippo-YAP1 axis. If components of the hippo-YAP1 axis were unphosphorylated, upregulated let-7a could not inhibit the proliferation of ADS JZ SMCs. Upregulated let-7a could not activate the hippo-YAP1 axis in verteporfin treatment.

CONCLUSIONS

Our findings suggest that the let-7a and hippo-YAP1 axis may act as important regulators of JZ SMCs proliferation, and upregulated let-7a may be an effective method to treat ADS.

The cannabinoid receptor CB1 affects the proliferation and apoptosis of adenomyotic human uterine smooth muscle cells of the junctional zone: a mechanism study

BACKGROUND

The denomyotic junctional zone (JZ) plays an important role in the pathogenesis of adenomyosis. Proliferating cell nuclear antigen (PCNA) is an important nuclear marker of cell proliferation. This study aimed to evaluate the effects of the cannabinoid receptor CB1 on proliferation and apoptosis in the JZ in women with and without adenomyosis.

METHODS

JZ smooth muscle cells (JZSMCs) of the adenomyosis and control groups were collected and cultivated. Immunohistochemistry and immunoblotting were used for protein localization and expression detection of CB1 and PCNA. Additionally, qRT-PCR was used to quantitatively analyse the mRNA expression of the two. AM251 and ACEA were used to regulate the function of CB1 receptors, and CCK-8 assay and flow cytometry assay were used to verify the proliferation and apoptosis of JZSMCs after regulation.

RESULTS

We demonstrated that in normal JZSMCs CB1 and PCNA messenger RNA (mRNA) and protein expression was significantly higher in the proliferative phase of the menstrual cycle than in the secretory phase. CB1 and PCNA expression in JZSMCs from women with ADS was significantly higher than that in control women and did not significantly differ across the menstrual cycle. CB1 receptor antagonist AM251 inhibited the proliferation of adenomyotic JZSMCs in a dose-dependent manner. The CB1 receptor agonist ACEA significantly promoted the proliferation of adenomyotic JZSMCs. The apoptosis rate of adenomyotic JZSMCs treated with AM251 was significantly higher than that of JZSMCs from the untreated control group. The apoptosis rate was significantly decreased in the ACEA group compared with that in the untreated control group. Furthermore, AM251 suppressed the phosphorylation of AKT and Erk1/2 in adenomyotic JZSMCs. The CB1 agonist ACEA significantly promoted the phosphorylation of AKT and Erk1/2.

CONCLUSIONS

Our results indicated that the levels of CB1 and PCNA were increased in patients with adenomyosis and that cyclic changes were lost. CB1 may affect uterine JZ proliferation and apoptosis in adenomyosis by enhancing AKT and MAPK/Erk signalling.

Differential expression of system L amino acid transporter subtypes in rat placenta and yolk sac

INTRODUCTION

Amino acid transport across the placenta is crucial for fetal growth. In rodent models, the visceral yolk sac (referred to as yolk sac hereafter) is also likely to contribute to fetal amino acid provision. System L amino acid transporters mediate the transport of essential amino acids. System L activity is mediated by light chains LAT1 (Slc7a5) and LAT2 (Slc7a8) which form functional complexes by heterodimeric linkage to CD98 (Slc3a2). LAT4 (Slc43a2) is monomeric, possessing overlapping amino acid substrate specificity with LAT1 and LAT2.

METHODS

This study investigates the expression of these LAT subtypes in fetus-matched rat placenta and yolk sac.

RESULTS

Slc7a5, Slc7a8 and Slc43a2 transcripts were expressed in placenta and yolk sac with similar expression patterns between sexes. LAT1 expression was significantly higher in placenta than yolk sac. Conversely, LAT2 and LAT4 expression was significantly higher in yolk sac than placenta; CD98 expression was comparable. LAT1, LAT2, LAT4 and CD98 were distributed to rat placental labyrinth zone (LZ) and junctional zone (JZ). LAT1 and LAT4 demonstrated higher expression in LZ, whilst LAT2 was more intensely distributed to JZ. LAT1, LAT2, LAT4 and CD98 were expressed in yolk sac, with punctate LAT1 staining to endodermal cell cytoplasm, contrasting with the intense LAT2, LAT4 and CD98 endodermal cell basolateral distribution, accounting for greater LAT2 and LAT4 expression in yolk sac compared to placenta.

CONCLUSION

LAT1, LAT2 and LAT4 are expressed in rat placenta and yolk sac implicating a combined role for these LAT subtypes in supporting fetal growth and development.

Rapid Effects of Oestrogen on Intracellular Ca2+ in the Uterine Junctional Myometrium of Patients With and Without Adenomyosis in Different Phases of the Menstrual Cycle

We investigated the role of oestrogen receptor 1 (ESR1) in regulating the [Ca²⁺]i concentration in the junctional zone (JZ) and its effect on adenomyosis. JZ smooth muscle cells (JZSMCs) were isolated from 17 control and 24 adenomyotic uteri, and membrane proteins were extracted from the cells. In the control group, the levels of membrane ESR1 and [Ca²⁺]i in the proliferative phase were significantly greater than they were in the secretory phase. While no difference was detected between the two phases, ESR1 and [Ca²⁺]i levels in the adenomyosis group were significantly higher in the proliferative and secretory phases than they were in the control groups. Oestradiol induced a rapid increase in [Ca²⁺]i in the JZSMCs of both groups. When pretreated with the ESR1 antagonist ICI 182,780, the increase in [Ca²⁺]i was clearly reduced in both groups compared with the control, but the differences were not significant. Filtered E-6-BSA also induced [Ca²⁺]i, and its actions were similar to those of oestrogen. Removal of extracellular Ca²⁺ did not alter the effect of oestradiol, but the phospholipase C inhibitor U73122 (10 μM) and 2-aminoethoxydiphenyl borate (5 μM) significantly reduced the oestradiol-induced [Ca²⁺]i flux. Oestradiol was unable to induce a [Ca²⁺]i flux in thapsigargin-depleted cells; this result indicated that oestradiol mediates the [Ca²⁺]i flux in JZSMCs through ESR1, which activates the phospholipase C pathway. ESR1 levels were assessed by Western blotting. Changes in the [Ca²⁺]i concentration induced by oestrogen stimulation were analysed by immunofluorescence. The ΔFCa²⁺ was calculated as the difference between baseline and peak fluorescence response to stimulation. We found that the abnormal intracellular [Ca²⁺]i response to oestrogen could account for aberrant JZ peristalsis.

The association between adenomyosis and recurrent miscarriage

OBJECTIVE(S)

To assess the association between the ultrasonographic presence of adenomyosis and recurrent miscarriage (RM).

STUDY DESIGN

A prospective matched case-control study was conducted between March 2018 and December 2018 at Ankara University Hospital. A total of 132 women were assessed with transvaginal ultrasonography for the presence of adenomyosis markers. The case group consisted of 66 women with RM. The control group consisted of 66 women without RM or any other gynaecologic conditions. The rates of ultrasonographic adenomyosis, using strict criteria, were compared between the groups. Other etiologic factors for RM were described in the case group. The primary outcome was the ultrasonographic diagnosis of adenomyosis.

RESULTS

The ultrasonographic diagnosis of adenomyosis, using diagnostic criteria of at least two markers, was significantly higher in the RM group when compared to the control group (19.7% vs. 6.1%, respectively; P = 0.035). The most common ultrasonographic finding in the RM group was heterogeneous myometrium (18.2%). In the RM group, there was at least one possible risk factor (including adenomyosis) for RM in 42 women (63.6%). The prevalence of adenomyosis in nine women with unexplained RM was 13.6%.

CONCLUSION(S)

The prevalence of adenomyosis was significantly increased in women with RM compared to healthy controls. Adenomyosis and uterine anomalies were the most common risk factors associated with RM.

Overexpression of Lin28B Promoted the Proliferation of Adenomyotic Smooth Muscle Cells of the Junctional Zone via Regulating Let-7a

The inner myometrium, also called the junctional zone (JZ), is believed to play a major role in the development of adenomyosis. Recently, we found that the lethal-7a (Let-7a) microRNA (miRNA) was clearly downregulated in the miRNA expression profiles of JZ smooth muscle cells (JZSMCs) of patients with adenomyosis. Lin28, including Lin28A and Lin28B, is responsible for the post-transcriptional downregulation of the Let-7 miRNA family. However, the expression pattern of Lin28 and the function of the Lin28/Let-7 axis in adenomyosis have not yet been identified. In this study, we aim to explore the potential roles of the Lin28/Let-7 axis in the development of adenomyosis. Immunohistochemistry, western blot, and reverse transcription polymerase chain reaction (RT-qPCR) were used to evaluate the Lin28 expression, respectively. The correlation between Let-7a, Lin28A, and Lin28B expression was further examined using Pearson's correlation analysis. RNA interference was used to inhibit Lin28B gene, and then Cell Counting Kit (CCK-8) assay was performed to detect the cell proliferation capacity. The results revealed that the expression levels of Lin28B were upregulated in the JZ of adenomyosis whatever about proteins or mRNA (P < 0.0001); furthermore, its mRNA expression level was negatively correlated with Let-7a (r = - 0.749, P < 0.0001). After inhibiting Lin28B gene, the proliferation capacity of JZSMCs in adenomyosis group decreased after 48 h (P < 0.05). These results indicated that Lin28B may be involved in the pathogenesis of adenomyosis by promoting the proliferation capacity of JZSMCs via regulating Let-7a.

Intrauterine cystic adenomyosis: Report of two cases

BACKGROUND

Cystic adenomyosis is a special type of adenomyosis. Its clinical manifestations lack specificity. Pelvic ultrasound and nuclear magnetic resonance imaging can help clarify the diagnosis. Because cystic uterine adenomyosis is rare in clinical work, it can be easily misdiagnosed or its diagnosis can be missed. Early surgical treatment and postoperative drug treatment can alleviate dysmenorrhea, menorrhagia, anemia, and other symptoms.

CASE SUMMARY

Two cases complained about abnormal vaginal bleeding and were diagnosed with intrauterine cystic adenomyosis by gynecological ultrasound and pathological examination. The clinical manifestations included dysmenorrhea, hypermenorrhea, and a history of cesarean section. Both cases underwent a surgery, and chocolate-like liquid was released from the cystic mass in the uterus and the manifestations were relieved.

CONCLUSION

Intrauterine cystic adenomyosis could be diagnosed by pathological examination and treated by hysterectomy or hystscopy to release the liquid inside.

Two- and three-dimensional transvaginal ultrasonography for diagnosis of adenomyosis of the inner myometrium

RESEARCH QUESTION

How diagnostically accurate is two-dimensional (2D-TVS) compared with three-dimensional transvaginal ultrasonography (3D-TVS) in diagnosing adenomyosis of the inner myometrium. What is the most accurate combination of ultrasonographic features?

DESIGN

Premenopausal women (n = 110) scheduled for hysterectomy or transcervical resection of the endomyometrium owing to abnormal uterine bleeding were consecutively enrolled. All participants had real-time 2D-TVS and, later, blinded off-line 3D-TVS to diagnose adenomyosis. Results were compared with a detailed histopathological examination of the inner myometrium as gold standard.

RESULTS

Prevalence of adenomyosis of the inner myometrium was 29%. For 2D-TVS and 3D-TVS, respectively, the diagnostic accuracy was sensitivity 72% (95% CI 53 to 86) and 69% (95% CI 50 to 84); specificity 76% (95% CI 65 to 85) and 86% (95% CI 76-93); and area under the curve (AUC) 0.74 (95% CI 0.7 to 0.8) and 0.77 (95% CI 0.7 to 0.9). Specificity of 3D-TVS was not statistically significantly better than 2D-TVS; the difference between them almost reached statistical significance (P = 0.06). The most accurate three-dimensional feature was junctional zone irregularity (JZ_max-JZ_min ≥5mm) (AUC: 0.78). A combination of two or more two-dimensional and two or more three-dimensional features was highly accurate (AUC: 0.77).

CONCLUSIONS

For diagnosing adenomyosis of the inner myometrium, 3D-TVS offers a high accuracy similar to 2D-TVS. Identification of junctional zone irregularity with 3D-TVS may be beneficial to diagnosis. Two or more two-dimensional features and two or more three-dimensional features combined may give a more objective diagnosis, and may be useful for clinical practice and future research.

Comparative analysis of high field MRI and histology for ex vivo whole organ imaging: assessment of placental functional morphology in a murine model

OBJECTIVES

The purpose of our study was to evaluate MRI as a tool to examine placental morphology in a murine model in comparison to classical histology techniques.

METHODS

Assessment of placental samples (n = 24) from C57Bl/6 J mice was performed using MR imaging and histomorphological analyses. To optimize image contrast for MRI, a protocol for gadolinium-mediated enhancement of placental tissue was established. To test method sensitivity, placental zone assessment with MRI and histology was applied to a model of prenatal stress exposure known to affect placental morphology (n = 10). Mean data acquisition time for both methods was estimated. Difference between groups was calculated using the Mann-Whitney U test.

RESULTS

Tissue fixation with formaldehyde and staining with gadolinium resulted in the best image quality. Placental functional zones were identified and measured with both MRI and histology. MRI and histology were able to detect changes in the L/Jz ratio upon a prenatal stress challenge (p = 0.001; p = 0.003). Data acquisition time was shorter using MRI assessment.

CONCLUSIONS

Ex vivo MRI analyses of murine placental functional morphology with MRI are feasible and results are comparable to time-consuming histology. Both MRI and histology allow the detection of experimentally induced morphological tissue alterations.

Perfusion of the uterine junctional zone in nulliparous and primiparous women assessed by DCE-MRI, as a function of menstrual cycle and hormonal contraception

PURPOSE

To evaluate the perfusion parameters of inner and outer myometrium in healthy nulliparous and primiparous women who are and who are not currently using hormonal contraceptives by means of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

MATERIAL AND METHODS

We performed pelvic 1.5T DCE-MRI on 98 women: 18 nulliparous non-users, 30 nulliparous users, 12 primiparous non-users and 38 primiparous users of hormonal contraception (mean age respectively 26.4, 25.8, 30.23 and 28.18years). The nulliparous non-users underwent DCE-MRI investigations during their follicular, ovulatory and luteal phase. Perfusion parameters (iAUC/volume, Ktrans, Kep and Ve) were assessed in the anterior and posterior junctional zone (JZ), outer myometrium and cervix.

RESULTS

In nulliparous non-users, the mean Ktrans and iAUC/volume showed a decrease from follicular to luteal phase (0.82 vs 0.55min^-1 for Ktrans, p=0/027 and 1.28 vs 0.68 for iAUC/volume, p<0.001). The anterior JZ demonstrated lower Ktrans (p=0.050) and higher Kep (p=0.012), in nulliparous non-users, lower Ktrans in nulliparous users (p<0.001) and lower Ve in primiparous users (p=0.012) than the anterior outer myometrium. Ktrans at the anterior and posterior JZ wall in nulliparous users was lower than in non-users (p=0.001 and p=0.013) and Ve at the anterior JZ wall in primiparous users was lower than in non-users (p=0.044).

CONCLUSION

This study provides data on normal perfusion parameters of inner and outer myometrium, which may be potentially useful in assisted reproductive therapy.

The abnormal expression of oxytocin receptors in the uterine junctional zone in women with endometriosis

BACKGROUND

The junctional zone (JZ), also called as the endometrial-myometrial junction, is related to peristaltic-like movements in the non-pregnant uterus. Hyperperistalsis and dysperistalsis of uterus constructions might underlie many important disorders such as dysmenorrhea, infertility, endometriosis, implantation failure. The major proteins for uterine contraction of the non-pregnant uterus may be Oxytocin (OT) and oxytocin receptor (OTR). The objective of this study was to inspect the expression of OTR in isthmic and mid-fundal parts of the uterine junctional zone at different stages of the follicular cycle in patients with and without endometriosis.

METHODS

Uterine biopsies containing endometrium and junctional zone were collected from the isthmic and mid-fundal parts of the anterior wall after hysterectomy. The OTR expression was evaluated by immunohistochemistry.

RESULTS

In the control uterus, OTR expression in the isthmic region was significantly higher than in the fundal region in the proliferative phase (p < 0.05) but significantly lower in the secretory phase (p < 0.05). And the expression of OTR in the proliferative phase was significantly higher than that in the secretory phase in both isthmic and fundal regions (p = 0.000 and 0.049, respectively). However, in endometriosis uteri, OTR expression in the isthmic region showed no significant difference with that in the fundal region in both proliferative and secretory phases (p = 0.597 and 0.736, respectively). In both isthmic and fundal regions, OTR expression was not significantly different between the proliferative phase and secretory phase (p = 0.084 and 0.222, respectively). OTR expression in fundal regions of revised ASRM I and II endometriosis were lower than that of revised ASRM III and IV (p = 0.049). In the fundal region of JZ, the expression of OTR in ovarian endometriosis was significantly lower than that in deep infiltrating endometriosis (p = 0.046). The expression level of OTR in the funds region is positively associated with the severity of dysmenorrhea in endometriosis group (r = 0.870, p < 0.05). Comparing to normal uteri, the expression of OTR in the secretory phase was significantly higher in the endometriosis uteri (p < 0.05). In the fundus of endometriosis uteri, OTR expression was significantly higher in both the proliferative and secretory phases (p = 0.045 and 0.028, respectively).

CONCLUSION

OTR expression in the JZ of women with endometriosis changes significantly, which may result in abnormal uterine contractile activity, reducing the endometriosis-related fertility and dysmenorrhea.

The Significance of MRI Evaluation of the Uterine Junctional Zone in the Early Diagnosis of Adenomyosis

Goal:

The aim of the study is to define the MRI appearance of disorder in the Junctional zone (JZ) in women with adenomyosis compared to those without it, given the importance of the JZ in the regulation of various reproductive events.

Materials and methods:

This was a prospective, comparative and open study. Patients with adenomyosis have been sorted in target group, n = 82, while the control group consisted of patients without adenomyosis, n = 82. All patients, from both groups have undergone a magnetic resonance imaging of the pelvis. Using a software tool for measurement, the thickness of the JZ was measured in T2w sag sequences in all patients from both groups (target and control) n = 164. Patients in the target group type adenomyosis were assessed and categorized either as: diffuse, focal, or Adenomyoma and the results were compared. The presence of endometriosis and myomas in both groups was evaluated and its coexistence with adenomyosis was analyzed as well.

Results:

Of the 82 patients in the target group, 81.7% of the patients had diffuse adenomyosis, while 18.3% had focal type with statistically significant difference (p <0.05). The results of the Mann-Whitney U test showed that p <0.05, implying that there is a statistically significant difference in the thickness of the JZ between the control and target group, therefore patients from the target group with adenomyosis had a statistically significantly thicker junctional zone than the patients in the control group. The JZ in the target group was on average M = 14,3mm, SD = 1.3mm, while the thickness of JZ in the control group without adenomyosis was M = 5,6mm, SD = 1,3. Chi-square shows that p <0.05, implying that there is a statistically significant difference in the number of patients with myomas between the two groups, where the myomas significantly over-represented in the target group with 32,9 % vs.6 %).

Conclusion:

MRI is the method of choice for imaging and evaluation of JZ as an important diagnostic marker in the diagnosis of adenomyosis. It is important to recognize this condition as early as possible and distinguish it from other pathologies in order for timely and appropriate treatment.

A longitudinal study of placental perfusion using dynamic contrast enhanced magnetic resonance imaging in murine pregnancy

INTRODUCTION

To evaluate changes in placental perfusion with advancing gestation in normal murine pregnancy using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI).

METHODS

Seven timed-pregnant CD-1 mice underwent DCE-MRI scanning longitudinally on gestational days (GD) 13, 15 and 17. Placentas were segmented into high (HPZ) and low perfusion zones (LPZ) using tissue similarity mapping. Blood perfusion of the respective regions and the whole placenta was quantified using the steepest slope method. The diameter of the maternal central canal (CC) was also measured.

RESULTS

An increase in perfusion was observed between GD13 and GD17 in the overall placenta (p = 0.04) and in the HPZ (p = 0.02). Although perfusion in the LPZ showed a slight increasing trend, it was not significant (p = 0.07). Perfusion, in units of ml/min/100 ml, in the overall placenta and the HPZ was respectively 61.2 ± 31.2 and 106.2 ± 56.3 at GD13 (n = 19 placentas); 90.3 ± 43.7 and 139 ± 55.4 at GD15 (n = 20); and 104.9 ± 76.1 and 172.2 ± 85.6 at GD17 (n = 14). The size of the CC increased with advancing gestation (p < 0.05).

DISCUSSION

Using longitudinal DCE-MRI, the gestational age-dependent perfusion change in the normal murine placenta and in its regional compartments was quantified. In mid and late gestations, placental constituent regions differ significantly in their perfusion rates. The CC diameter also showed increase with advancing gestation, which may be playing an important role toward the gestational age-dependent increase in placental perfusion.