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This is an MRI of the abdomen and pelvis

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in a patient who presented at 19 weeks gestation

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from the Maternal-Fetal Medicine

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Clinic after abnormal obstetrical ultrasound.

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The patient had a history of

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multiple prior cesarean sections.

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Again, we've hung our steady-state free

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precession images on the left and our

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turbo spin-echo images on the right.

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We can see T2 heterogeneous

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myometrium in both cases.

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What's interesting about this case

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is that superior to the gestational

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sac within the uterine fundus,

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we see a T2 hyperintense structure that

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appears to be surrounded by the junctional zone.

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So this is the endometrial

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cavity for this patient.

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As we scroll inferiorly, we begin

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to see placental tissue, which

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has no overlying myometrium.

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There is frank extension of this placenta

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beyond the uterine serosa, and really there's

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an abrupt juxtaposition of myometrium here

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along the anterior aspect of the uterus.

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So there's myometrium and then

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a sharp demarcation between that

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tissue and the adjacent placenta.

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As we scroll inferiorly, we see

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additional placental tissue in the region

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of the cervix and the upper vagina.

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We also see prominent vessels in the

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left hemipelvis, which appear to be

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recruited from the left uterine artery.

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We can follow quickly the uterine

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arteries and identify their origin.

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So here's the abdominal aorta.

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This is the bifurcation.

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This is the left common iliac artery.

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It divides into external and internal divisions.

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This is the internal iliac artery.

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And then those anterior branches are

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the uterines, which seem to be directly

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recruited by the placenta here.

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These are coronal T2-weighted images of the

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abdomen and pelvis for the same patient.

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Again, in the coronal plane, we can see that

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the fundus of the uterus is relatively normal

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in appearance with T2 dark junctional zone,

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and then the T2 hyperintense endometrium.

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There is also T2 hypointense debris

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within the endometrial cavity superiorly.

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We see a sharply demarcated gestational sac

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with surrounding placenta, which is abruptly

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juxtaposed to the uterine myometrium.

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So again, we see T2 heterogeneous myometrium,

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which is directly abutting the placental tissue.

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The placenta is also heterogeneous

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with multiple placental bands, and

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it's relatively lobular in appearance.

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As we scroll anteriorly for this

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patient, we can see that there is really

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no intervening myometrium surrounding

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the placenta for this patient.

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Let's look at the sagittal

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images for this patient now.

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Again, we see the uterine fundus with a small

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amount of debris in the T2 hyperintense cavity.

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We also see the gestational sac, which

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contains a vertex presentation fetus,

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and T2 heterogeneous myometrium, which is

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directly abutting the gestational sac and

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the placenta, which we see inferiorly.

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Again, we see no overlying myometrium.

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As we try to trace it superiorly,

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there's an abrupt cutoff of the

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myometrium with the placenta located

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along the low anterior uterine segment.

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Importantly, as we scroll through the

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region of the low anterior uterine

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segment in the region of the bladder dome.

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If we attempt to trace the detrusor signal

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of the bladder, we can see that there's focal

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disruption of the bladder here posteriorly.

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And it's really only occurring on a single

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slice or one or two slices for this patient.

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And so this is the area where

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we see the bladder disrupted.

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And this was a site of focal bladder invasion.

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The appearance of this

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pregnancy is abnormal, right?

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We've not really been able to determine whether

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this gestation is within the endometrial cavity.

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And that's because this appearance is actually

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that of a cesarean scar ectopic pregnancy

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with an externalized placenta and placenta

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percreta focally invading the bladder dome.