Interactive Transcript
0:00
In patients with suspected placenta percreta,
0:03
it's particularly important
0:05
to try to identify any structures
0:07
that may be invaded by the placenta.
0:10
One of the most frequently invaded
0:12
structures is the bladder dome.
0:14
When evaluating the bladder dome,
0:16
it's important to evaluate the signal
0:18
of the bladder wall in its entirety.
0:20
So you can trace the signal of the bladder
0:22
wall, which should appear T2 hypointense.
0:26
Bladder dome invasion may be difficult to detect
0:29
because it often appears as a signal abnormality
0:32
on only a single slice of the images.
0:35
This may look like focal disruption
0:38
of the normal detrusor signal.
0:40
You can also see blurring or irregularity
0:43
of the bladder wall or the bladder mucosa.
0:46
As is the case in this patient with a low
0:48
lying placenta and placenta percreta, we see
0:51
focal disruption of the bladder wall signal.
0:53
With a small amount of focal protrusion of
0:56
placental signal into the bladder lumen.
0:59
In patients who have close approximation of
1:02
the bladder by the placenta, but not frank
1:04
invasion of the bladder dome, you may also see
1:07
prominent vessels in the supravesicular fat
1:09
pad, which will appear as T2 dark flow voids.
1:13
Identifying bladder dome invasion
1:15
is also particularly important.
1:18
Because at the time of delivery, if bladder dome
1:20
invasion is suspected, the surgeons will have
1:23
to make a cystotomy, or opening in the bladder
1:25
dome, and then repair it, which may require
1:28
involvement of urology at the time of surgery.
1:32
Another key feature that should be evaluated
1:34
in patients with suspected placenta
1:36
percreta is involvement of the parametrium
1:40
and recruitment of the uterine vessels.
1:43
The parametrium is a fibrous band of
1:45
tissue that separates the supravaginal
1:47
cervix from the urinary bladder.
1:50
You will not see the parametrium in a pregnant
1:53
patient because of all of the vascularity
1:55
that normally proliferates in the pelvis.
1:59
The parametrium extends between
2:00
the broad ligaments, and the uterine
2:02
arteries run within the parametrium.
2:05
So in patients who have placenta percreta, as
2:08
is the case here, if you see recruitment of
2:11
the uterine arteries by the aberrant placenta,
2:15
you can imply that the parametrium is involved.
2:18
So in this patient, we're at the level of the
2:21
urinary bladder on this T2-weighted axial image.
2:24
We can see a placental tissue mass in the lower
2:27
uterine segment near the internal cervical os.
2:31
The uterine arteries are branches off of the
2:34
anterior division of the internal iliac artery.
2:37
And we can see in this patient T2
2:39
dark vessels, which are extending
2:41
directly from the region of the uterine
2:43
arteries toward the abnormal placenta.
2:47
Identifying parametrial involvement and uterine
2:50
vascular recruitment is important because
2:52
it may necessitate radical hysterectomy.
2:55
If branches of the uterine arteries are
2:56
involved, the surgeon will have to take
2:58
a broader, more lateral vascular pedicle
3:01
rather than a traditional hysterectomy.
© 2024 MRI Online. All Rights Reserved.