In a quest for the common bile duct

[Seaglass]

So I'm having trouble finding the CBD on RUQ ultrasound and I haven't found any good reasources to help (the radiology text doesn't even mention it). Anyone have a technique that works? Picutres would be helpful.

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[southerndoc]

I learned by experience/practice and with the help of our ultrasound fellow and director. I really didn't read anything good about how to find it (it's not described well, even in the ultrasound text by Ma).

I have found that it's much more difficult to find the "mickey mouse" sign than it is to find an oblique or parallel view of the CBD. I usually color flow doppler it just to make sure I'm looking at the right thing.

I usually find it best with an oblique view (the probe does not have to be in a sagittal or transverse plane, oblique actually works best for gallbladders). The best location seems to be in the right upper quadrant and not in the lateral chest/flank view (although I have sometimes found it there).

Maybe our Christiana colleage could comment on this as they seem to be very experienced with ultrasounds.

 

[EMIMG]

It does take practice. Finding the so-called Mickey Mouse sign does help, and color flow does help. I typically find that the GB is best scanned in the Left-lateral position. Try to find the portal vein which is normally best found in the transverse plane. Then look anterior to the portal vein. Normally the hepatic artery is Mickey's left ear and the CBD is his right ear.

As stated prior, it is better if you have color flow capabilities so you can ensure that you are seeing the portal vein and then the CBD instead of a different vascular structure such as the hepatic artery.

But, the best thing to do is practice, practice, and practice. If you cannot find it in the standard approach, sometimes it is helpful to take a slightly more lateral approach and shoot through the rib spaces.

 

[peksi]

My approach to all ultrasound is teachnig landmarks first.

For me in the RUQ the landmark is the portal vein. I identify the portal vein, remember it has echogenic walls, turn on this to get a longitudinal and look for the "duct' this may be the common hepatic, remeber this joins to form the CBD, generally you can find the hepatic artery and this is usually well identified with doppler, however I usually just use greyscale. i try to teach that there are two distinct concepts with scanning planes (sag, transverse etc. ) This is that there is the plane of the patient, as well as the plane of the organ or structure of interest, eg the coronal endovaginal view is often a transverse view of the uterus etc., but is coronal to the patient.

I identify the portal vein, turn to get a sagittal view of the portal vein, and search for the duct running it's length and anterior to it, i can usually identify it with this approach.

Paul

 

[daveshnave]

My approach to all ultrasound is teachnig landmarks first.

For me in the RUQ the landmark is the portal vein. I identify the portal vein, remember it has echogenic walls, turn on this to get a longitudinal and look for the "duct' this may be the common hepatic, remeber this joins to form the CBD, generally you can find the hepatic artery and this is usually well identified with doppler, however I usually just use greyscale. i try to teach that there are two distinct concepts with scanning planes (sag, transverse etc. ) This is that there is the plane of the patient, as well as the plane of the organ or structure of interest, eg the coronal endovaginal view is often a transverse view of the uterus etc., but is coronal to the patient.

I identify the portal vein, turn to get a sagittal view of the portal vein, and search for the duct running it's length and anterior to it, i can usually identify it with this approach.

Paul

While you're at it....


Do you have any advice for visualizing the ovaries on transabdominal? Obviously transvaginal is optimal, but if you don't have the time and/or the patient is going for an official transvaginal study imminently and you don't want to upset her, what's your advice for visualizing the ovaries? A full bladder is ideal. How about any landmarks to get me started? Do you look for the iliacs first or rather just scan lateral to the uterus in the adnexa? Granted I'm new to ultrasound, but I feel like I'm floundering....

 

[EMIMG]

Typically I find the best way if you are looking for them is to attempt to find the fundus and then see about following the tubes out. I think that this typically works well with the endovaginal and can work with the transabdominal.

I find that the transverse orientation typically works much better than longitudinal to localize, but remember that it is a 3-d structure so you should really try to scan through in both long and short axis.

But, if you are looking for the ovaries or ovarian pathology, you really should find the time to do the endovaginal approach. Remember, ultrasound is used as an adjunct to patient care and we should be using it to enhance the care the patient receives, and not do a half-hearted effort.

 

[RADRULES]

Ask a radiologist, that is our job.

 

[southerndoc]

Ask a radiologist, that is our job.

For help in teaching us how to locate the CBD?

Or are you referring to asking a radiologist to perform and interpret the study?

If it's the former, then great, please teach us. If it's the latter, then you of all people should realize that not all hospitals have 24-hour ultrasound techs and radiologists staffing the hospital 24 hours daily. What are we to do then? Board our patient that comes in at 6 pm overnight until the radiologist and tech comes in at 8:30 to perform and read the scan?

I've become very comfortable with ultrasound. That's one of the big strengths of my program. It's nice to E-FAST a trauma patient that comes in to see if they have blood in their abdomen, pneumothorax, or pericardial effusion; to quickly rule out a DVT; to assess for hypokinesis in suspected MI patients with non-specific ECG changes; or to see if there are stones in the gallbladder, pericholecystic fluid, or gallbladder wall thickening. I have to admit that the CBD can be tough to find sometimes, and I do not always trust my reading on this one.

There have been two instances where I have detected a DVT in a patient, but the patient's official DVT study is read as negative. How do I know I was right? Because the patients were asked to come back the next day to have a repeat study, which was officially read as DVT. Is this technical error or is this a fluke in how we test for DVT's? (To date, none of the negative DVT studies I've performed have had official studies read as positive -- perhaps it's the fact that we often assess more of the vein than most techs assess.)

OK, off my soapbox about 24-hour availability of ultrasound.