Performing an Estimated Placental Volume (EPV) Measurement

Transcript

• 00:00It's my pleasure to be here with
• 00:02Doctor Steve Rad, a maternal fetal
• 00:04medicine specialist in Los Angeles,
• 00:06CA, and he's going to demonstrate how
• 00:08to do an estimated placental volume.
• 00:11Thank you. So here we are
• 00:14scanning and we're going to
• 00:16be looking at the placenta.
• 00:18As you can see, the placenta is posterior.
• 00:21We want to scan through the placenta.
• 00:24And 1st get a feel and orientation
• 00:27of where the placenta is.
• 00:29We want to find we want to be
• 00:32perpendicular to the plane of the placenta,
• 00:35and find a Crescent where the
• 00:38placenta appears, Crescent shaped.
• 00:41So here, as we scan through the placenta.
• 00:46You notice that?
• 00:50Approximately this area.
• 00:54With the maximum width. And.
• 00:59You can start to tell it's like a crescent
• 01:02can confirm once you get to that area.
• 01:08The edges become a little bit more. Clear.
• 01:13Right. I'll say one thing.
• 01:14When you're exactly perpendicular,
• 01:15these sound waves go down and
• 01:18come back to the transducer
• 01:20and the image becomes sharp.
• 01:22So you're looking for a sharp image
• 01:24across the whole width of the
• 01:26placenta from the tip to the tip.
• 01:29When you have this crescent image.
• 01:31Perfect. I think that's here.
• 01:33Excellent. So what do you do next?
• 01:35So next we'll be doing some measurements.
• 01:37We're going to imagine the.
• 01:40Placenta resting on a table.
• 01:43And we're going to be first
• 01:45measuring the width of the placenta.
• 01:48And we do that by measuring
• 01:50from each edge of the placenta
• 01:53and one edge to the other.
• 02:00And that gives us. The width of the placenta.
• 02:04Perfect. I'd like to think of this
• 02:06as the tip to tip measurement and
• 02:09which you've done in segment #1.
• 02:11Perfect. Next, we're going
• 02:13to be measuring the height of the placenta,
• 02:15and we locate the apex of the placenta.
• 02:23And we will measure.
• 02:26From the base of the placenta,
• 02:28a perpendicular line.
• 02:30To our width line.
• 02:34And I think of this as think of
• 02:36going over a bridge that is curved.
• 02:38When you get to the very top of the bridge,
• 02:40you know where the apex is.
• 02:41That's what you're thinking
• 02:43about with this crescent.
• 02:44You're finding the topmost
• 02:46point of this placenta.
• 02:49And we want our lines to be perpendicular.
• 02:51So what I do sometimes is swing
• 02:53side to side just to confirm.
• 02:58That were exactly perpendicular.
• 03:07And then we will save that measurement.
• 03:10Next, we're going to measure
• 03:12the placenta thickness.
• 03:14And that is going to be from
• 03:15starting from the same point where
• 03:17we measured the height and we
• 03:20will draw a line from there to the
• 03:24edge of the placenta fetal surface
• 03:26where meets the amniotic fluid.
• 03:29Perfect. And I'll just make the point.
• 03:31This last segment, the thickness measurement,
• 03:34starts at the same apex point and
• 03:37follows exactly the same line that
• 03:39you've created for the height.
• 03:41And that is perfect the way you just did it.
• 03:43Precisely. And then we save our
• 03:46measurements. And they're listed here,
• 03:49and those measurements can be put into an
• 03:52app either for an iPhone or Android phone,
• 03:54or if your machine is able to
• 03:57take the equation internally,
• 03:59you can have the machine do
• 04:00the calculation for you,
• 04:01but as those 3 numbers the width,
• 04:05the height and the thickness
• 04:06measurements: 1, 2 and 3 shown
• 04:08here that allow you to calculate the
• 04:11three-dimensional volume of this placenta.
• 04:14Exactly, and it doesn't take that long.
• 04:18And sometimes I personally repeat it.
• 04:22One or two times to confirm,
• 04:24and usually you'll get the very
• 04:25similar exact measurements.