0:00

Because of the concern for significant

0:02

vascular recruitment in the setting of placenta

0:04

percreta, the previous patient was sent for

0:07

CTA of the abdomen and pelvis to further

0:09

delineate the degree of vascular recruitment.

0:12

On the left, we have arterial phase

0:14

contrast-enhanced CT images of the abdomen

0:17

and pelvis, and on the right, we have

0:18

venous phase contrast-enhanced images.

0:22

As we scroll in further, the

0:22

gravid uterus comes into view.

0:25

Let's take a look at the normal appearance of

0:27

the uterine myometrium on contrast-enhanced CT.

0:31

Again, it's somewhat heterogeneous

0:32

in appearance, and looks similar

0:35

to what we saw on the prior MRI.

0:37

We see the fetus with an appropriate

0:39

amount of surrounding amniotic fluid.

0:43

As we scroll inferiorly, the placental tissue

0:45

begins to come into view, and we can see

0:48

that it is heterogeneously enhancing in the

0:50

arterial phase, and relatively homogeneously

0:53

enhancing or filling in in the venous phase.

0:57

When we reach the region of the inferior uterus,

1:01

particularly that inferior most lower uterine

1:04

segment in the region of the lower cervix

1:06

and upper vagina, again we see this mass of

1:10

placental tissue which is bulging and extending

1:13

toward the left adnexa and left pelvic sidewall.

1:17

In the region of the previously noted

1:19

aberrant vasculature on MRI, we can see

1:22

that on the arterial phase, there is a

1:24

not insignificant amount of arterially

1:27

enhancing vasculature in the left hemipelvis.

1:31

There are also a number of vessels that

1:34

enhance in the venous phase on this CT.

1:38

If we come more superiorly and we trace

1:41

the arterial vessels from the level of the

1:44

aortic bifurcation, we can see the left

1:47

common iliac artery, which divides into

1:50

the external and internal iliac arteries.

1:54

As we scroll inferiorly,

1:56

we see anterior branches

1:58

of the internal iliac artery, which

2:00

directly extend toward this placental mass.

2:04

And they also extend inferiorly

2:06

along the cervix and upper vagina.

2:09

And so in this patient, concern was raised

2:12

for not only parametrial involvement,

2:14

but recruitment of arterial vessels

2:16

from the cervical-vaginal plexus.

2:19

These are coronal arterial and

2:21

venous phase CT images of the abdomen

2:23

and pelvis for the same patient.

2:26

Again, in the lower uterine segment on

2:28

the left side, we see a bulge of placental

2:30

tissue which is directly abutting and

2:32

exerting mass effect on the bladder dome.

2:36

In the left hemipelvis, we can see

2:38

extensive aberrant vasculature, extending

2:41

from the branches of the internal iliac

2:43

artery toward the abnormal placenta.

2:47

These are sagittal CT images of the

2:48

abdomen and pelvis for the same patient.

2:51

The placenta previa is particularly

2:53

apparent on these images,

2:55

in addition to the direct abutment

2:57

of the bladder dome by the placenta.

3:00

We also see the recruited arterial vasculature

3:03

in the left hemipelvis on the sagittal images.

3:06

I'd also like to point out that there

3:08

are a significant number of vessels

3:09

running within the perivascular fat

3:11

pad and adjacent to the bladder dome.

3:15

One of the benefits of obtaining thin-section,

3:17

high-resolution CT images of the abdomen

3:20

and pelvis in this patient population is

3:22

our ability to reconstruct these images

3:25

and generate 3D and cinematic renderings.

3:28

This is a 3D rendering of

3:29

the CT data for this patient.

3:32

Again, we can see the placental bulge in the

3:34

left lower uterus, and the 3D rendering

3:37

nicely illustrates the extensive tangle

3:39

of aberrant vasculature that has been

3:41

recruited by the placenta in the left

3:43

hemipelvis compared with the right.

3:46

An additional reconstruction that we're

3:48

able to generate when we obtain CT for this

3:50

patient population is cinematic rendering,

3:53

which is a post-processing technique

3:55

that utilizes photorealistic lighting and

3:57

is generated on a separate workstation.

4:00

We can see the normal myometrial

4:01

vasculature in this patient, as

4:04

well as the fetal sacrum and femur.

4:06

Inferiorly, we can see the placenta, which

4:09

is protruding from the lower uterine segment.

4:12

Cinematic rendering is particularly helpful

4:14

in delineating the texture of structures

4:16

and in performing textural analysis.

4:18

And we can see a clear delineation between

4:20

the myometrium and myometrial vasculature

4:23

and the aberrant placenta in this patient.

4:26

As we scroll through the cinematic

4:28

rendering, we're also able to rotate the

4:30

images and provide additional views of the

4:33

pathology in the lower uterine segment.

4:36

This is particularly helpful in cases

4:38

where operative planning is of the

4:39

utmost importance, and we try to minimize

4:42

peripartum hemorrhage in these patients

4:44

by doing an extensively planned surgical

4:46

approach and also planning for peripartum

4:49

procedures like uterine artery embolization.