Re: intrauterine ectopic

From: Terry J. DuBose (tjdubose@uams.edu)
Tue Aug 27 13:10:36 2002

Dr. Fougner, very good point... in fact seeing outliers is the reason I like more measurements... you can "see" the fetal proportionality. Granted, a short femur is not necessarily diagnostically specific, but it is better to have the information than not to have it. And "age range analysis" allows one to compare all the parameters at once without a bunch of graphs that are much more difficult to interpret, which is another reason I like more measurements.

For example look at this BBII report in the 23rd week with normal proportions and all parameters falling within +/-1SD of the mean (time-series plot across the bottom of the screen). http://www.io.com/~dubose/BB-REPT.GIF

Then this case near term (38th week by head parameters), that has short femurs and humeri.... http://www.io.com/~dubose/BB-38-1.GIF

Granted from this information one can not Dx Downs or other conditions, but I do believe that it is helpful to know that the femur is at a -1.5SD and the humerus is at a -0.7SD below the mean.

Are you saying we should ignore outliers? That is the same argument that Dr. Sabbagha had with Dr. Hadlock in the 1980's... Sabbagha felt that the average of multiple fetal parameters would "dilute" the accuracy of the "true" or "correct" measurement. The problem was that due to individuation of fetal proportions, some long, some short, some fat, some thin, some brachicephalic, some dolichol, and on and on, it was impossible to determine which parameter in any given case was the "true" measurement. So we all now use Hadlock's average of multiple fetal parameters' ages for dates. But that is only part of the "picture"… there is also the question of how far from the mean or average of the multiple fetal parameters can a single parameter be without being "too far" out… an outlier? Thus the ARA to view the fetal proportions as a distribution about the mean. Baslically, all parameters' should be within +/-8% of the age... Hadlock & Bowie's distribution... personally I prefer to use +/-10% of the age because it is easier to calculate, the 2% difference is very small, gives the advantage to the fetus, and is based upon the average of up to 12 parameters' ages rather than Hadlock's 4.

Of course, we must also realize that I am approaching this from a non-physician sonographer's point of view... my job is to provide the physician with as much accurate information as I can... not nearly so difficult, I realize, as making the final Dx from all of this.

For more about BBII and Age Range Analysis (ARA) see: http://www.io.com/~dubose/BB-WEBH.HTM and http://www.io.com/~dubose/bbii.html Also, Fetal Sonography, chapter 7, Fetal Size/Age Analysis.

Peace, Terry J DuBose, M.S., RDMS Little Rock, Arkansas USA

----------------------------------------------------------

ultrasound@obgyn.net writes: ---------------------------------------------------------- >Terry,

--
----------------------------------------------------------
>
>more parameters may smooth datasets but problems arise with statistical
>outliers.  for example, does a short femur suggest down's, short stature
>or a younger fetus?
>
>art
>
>At Mon, 26 Aug 2002, Terry J DuBose wrote:
>>
>>Yes, I know you are correct about garbage, but one person's garbage may
>>be another's found treasure.
>>
>>Multiple fetal parameters do provide better data, and the more parameters
>>the higher the statistical power.  I really do miss the days before
>>managed care when there was time to take measurements and study the
>>results.  Sonography is much more accurate than it is given credit for
>>being, I am sure.  There is a lot of sloppy work being done because the
>>reputation is that it is fuzzy and highly variable.  However, the normal
>>embryos are quite uniform... it is the operator dependency that is the
>>main variable... and the equipment, knowledge, and skill of some of those
>>operators.
>>
>>Peace,  Terry
>>
>>-------------------------------------------------
>>
>>-------------------------------------------------
>>On Mon, 26 Aug 2002 16:59:30 -0500 evsono@pipeline.com (art fougner, md)
>>-------------------------------------------------
>>-------------------------------------------------
>>writes:
>>-------------------------------------------------
>>
>>--
>>-------------------------------------------------
>>> Terry -
>>-------------------------------------------------
>>>
>>-------------------------------------------------
>>> sure as long as the measurements mean something - "measure twice,
>>> cut
>>> once & you'll save a lot of wood" is an old carpenter's expression
>>> that
>>> works.  BUT - if your measurements have not been validated for a
>>> particular situation - then garbage in -> garbage out may apply.  in
>>> the
>>> end we all subscribe to Hunter's theorem - "works for me!"
>>>
>>> art
>>>
>>> At Sun, 25 Aug 2002, Terry J DuBose wrote:
>>> >
>>> >No argument from me either.  Obviously the larger the structure the
>>> more
>>> >accurate the measurement because a few pixels at 1-3 mm will be a
>>> larger
>>> >percent error than those same few pixels at 10 mm or more. For
>>> this
>>> >reason the CRL continues to be more and more accurate until the
>>> >embryo/fetus begins to flex and extend, or gets too large for the
>>> field
>>> >of view.  There are CRL tables out to 18-19 weeks, but the accuracy
>>> is
>>> >less than that of the head at that late date.   However, I have
>>> found
>>> >that we can measure very early simply by measuring the mass of
>>> cells
>>> >where the cardiac activity is observed.
>>> >
>>> >Often we are called upon to evaluate a pregnancy for early spotting
>>> and
>>> >we don't always have the luxury of choosing the exact date.  If it
>>> is at
>>> >5-6 weeks, then I always measure the mean sac as well as the CRL
>>> and EHR
>>> >for age. If all three give a similar age, then that is a "warm
>>> fuzzy",
>>> >but if the EHR trails the CRL age by more than 6 days, then it is
>>> >worrisome.  The mean sac is more variable due to shape differences
>>> due to
>>> >the placement in the uterus, degree of bladder pressure, myomas,
>>> etc.
>>> >However, I did not like the sac after 7 weeks because the CRL is
>>> much,
>>> >much better at that time.  Even the EHR age is better than the mean
>>> sac
>>> >in normal embryos, but nothing is better than the CRL after the 6th
>>> week.
>>> >
>>> >Granted, in the 5th week we are dealing with some variables we
>>> don't
>>> >completely understand... the implantation date and it's influence
>>> on
>>> >growth... and very small structures with larger percent errors.
>>> >
>>> >Not only was Robinson and Shaw-Dunn's CRL table very good for the
>>> >equipment they used, their EHR was also remarkably accurate.  Only
>>> they
>>> >apparently could not see the EHR before about 7 weeks, and only saw
>>> the
>>> >two week acceleration to the early 9th week.  Others who measured
>>> the EHR
>>> >later, with better equipment saw the earlier acceleration
>>> (Hertzberg,
>>> >Mahony, Bowie: 1st Trimester Fetal Cardiac Activity; JUM 1988,
>>> >7:573-575), but they completely missed the high peak rate in the
>>> early
>>> >9th week that Robinson & Shaw-Dunn documented.  They missed the
>>> peak
>>> >because they did not use M-mode, but tried to visually count the
>>> heart
>>> >rate that reaches 175+ and only found a plateau around 140-160
>>> B/M.
>>> >
>>> >I like all the measurements I can get... the more the better,
>>> whenever it
>>> >is...
>>> >
>>> >Peace, Terry J DuBose, M.S., RDMS
>>> >Little Rock, Arkansas USA
>>> >
>>> >On Sun, 25 Aug 2002 19:07:38 -0500 evsono@pipeline.com (art
>>> fougner, md)
>>> >writes:
>>> >> i agree - anecdotally first tried to date a pregnancy from a 6
>>> wk
>>> >> fetal
>>> >> pole only to find myself wiping the yolk off my face so to speak
>>> at
>>> >> 13
>>> >> wks when i not surprisingly redated the pregnancy.  i avoid
>>> >> assigning
>>> >> dates until crl is at least 7 wks size.  amazing how hugh
>>> >> robinson's
>>> >> table worked out - even with the old compound b scanner.
>>> >>
>>> >> art
>>> >>
>>> >> At Sun, 25 Aug 2002, Allen Worrall wrote:
>>> >> >
>>> >> >I am of the opinion that measuring the greatest embryonic
>>> length
>>> >> (not
>>> >> >properly called a CRL in a very early embryo) is a somewhat
>>> >> imprecise thing
>>> >> >at 5.5-6 menstrual weeks,  because it is difficult to know
>>> exactly
>>> >> where to
>>> >> >put the cursors on a very early fuzzy embryonic pole. And MSD
>>> is
>>> >> not very
>>> >> >precise (but can be measured more precisely than greatest
>>> embryonic
>>> >> length,
>>> >> >since you can be pretty sure where to put the cursors when you
>>> are
>>> >> measuring
>>> >> >the gestational sac). I feel this way despite having a very
>>> good
>>> >> machine,
>>> >> >excellent transvaginal probe, and ability to enlarge the
>>> embryonic
>>> >> pole as
>>> >> >much as needed.
>>> >> >
>>> >> >I have the feeling that gestational age may be more accurate
>>> when
>>> >> measured
>>> >> >at 7-8 weeks, when the embryo is larger and you can see just
>>> where
>>> >> to put
>>> >> >the cursors.
>>> >> >
>>> >> >Anyone have a comment pro or con?
>>> >> >
>>> >> >Allen
>>> >> >
>>> >> >Joseph A Worrall MD RDMS
>>> >> >OB/GYN Ultrasound at the Fairbanks Clinic
>>> >> >Fairbanks, Alaska, USA
>>> >> >jworrall@alaska.net
>>> >> >http://www.obgynsono.com
>>> >> >
>>> >
>>


>>>>> >>> >>----- Original Message -----
>>> >> >From: "Terry J DuBose" <tjdubose@juno.com>
>>> >> >To: "Multiple recipients of list ULTRASOUND"
>>> >> ><ultrasound@mail.medispecialty.com>
>>> >> >Sent: Sunday, August 25, 2002 9:52 AM
>>> >> >Subject: Re: intrauterine ectopic
>>> >> >
>>> >> >> Dr. Fougner, I agree... I have also seen EHRs at 1 mm...
>>> >> correlates to
>>> >> >> about 5.0 weeks after LMP and a mean EHR of of 94 B/M (my
>>> table
>>> >> 7-5,
>>> >> >> Fetal Sonography, 1996.  The heart rate will usually
>>> accelerate
>>> >> at a rate
>>> >> >> of 3.3 beats per minute per day from when it is first
>>> detected
>>> >> until a
>>> >> >> CRL of 2.6-2.8 mm or 9.2 weeks before beginning a
>>> deceleration
>>> >> from a
>>> >> >> peak of about 189 B/M at 9.2 weeks (+/-1 to 2 days).  The EHR
>>> >> time series
>>> >> >> curve has the shape of a classic damping  feed-back curve.
>>> >> >>
>>> >> >> Dr. Ronald Shats, Amsterdam 1991, TV Sonography in Early
>>> Human
>>> >> Preg. said
>>> >> >> that if you see cardiac activity you are seeing the embryonic
>>> >> pole.  He
>>> >> >> also indicated that one of the problems in getting an exact
>>> age
>>> >> is there
>>> >> >> appears to be a variation in time of first heart beating  due
>>> to
>>> >> >> variations in implantation times.  On page 39 of his
>>> dissertation
>>> >> that
>>> >> >> "References to days are given only as guidelines and thus are
>>> >> >> approximations of the truth because early stages of
>>> implantation
>>> >> of the
>>> >> >> human blastocyst have not been observed.   Most knowledge
>>> about
>>> >> early
>>> >> >> implantation is based on studies of the Rhesus monkey, but
>>> the
>>> >> process is
>>> >> >> thought to be essentially similar to man."
>>> >> >>
>>> >> >> Sonography has given us a very early window on embryonic
>>> >> development.
>>> >> >> The correlation of the CRL, EHR, and hCG have not been
>>> thoroughly
>>> >> studied
>>> >> >> and are not well understood. We have gotten to within about 3
>>> >> days of a
>>> >> >> "true" date, but can't seem to resolve it more than that.
>>> >> >>
>>> >> >> One of the most interesting questions in human development,
>>> >> IMHO.
>>> >> >>
>>> >> >> Peace, Terry J DuBose, M.S., RDMS
>>> >> >> Little Rock, Arkasas USA
>>> >> >>
>>> >> >> On Sun, 25 Aug 2002 11:08:06 -0500 evsono@pipeline.com (art
>>> >> fougner, md)
>>> >> >> writes:
>>> >> >> > Martin -
>>> >> >> >
>>> >> >> > have seen as Terry so fondly calls it - embryonic cardiac
>>> >> activity
>>> >> >> > with
>>> >> >> > 1 mm fetal poles using 7 - 8 Mhz frequency vaginal
>>> >> transducers.
>>> >> >> >
>>> >> >> > Sharon -
>>> >> >> >
>>> >> >> > have seen for want of a better term - intra-amniotic yolk
>>> sacs
>>> >> twice
>>> >> >> > -
>>> >> >> > both pregnancies ended in spontaneous Ab.  wonder if your
>>> >> findings
>>> >> >> > could
>>> >> >> > represent the early appearance of the extrachorial
>>> gestation?
>>> >> do
>>> >> >> > you
>>> >> >> > have images? i sense a case report.
>>> >> >> >
>>> >> >> > art
>>> >> >> >
>>> >> >> > At Sat, 24 Aug 2002, Sharon Brown wrote:
>>> >> >> > >
>>> >> >> > >At Sat, 24 Aug 2002, Martin Necas wrote:
>>> >> >> > >>
>>> >> >> > >>Dear Sharon,
>>> >> >> > >>
>>> >> >> > >>I don't think it is possible to get fetal heart tones at
>>> 6-7
>>> >> weeks
>>> >> >> > GA.
>>> >> >> > >>That's just way too early.
>>> >> >> > >>
>>> >> >> > >>>From your description, are you saying that the embryo is
>>> >> outside
>>> >> >> > the
>>> >> >> > >>gestational sac and outside the endometrium...  so that
>>> seems
>>> >> to
>>> >> >> > imply
>>> >> >> > >>that the embryo is within the myometrium?
>>> >> >> > >>
>>> >> >> > >>A couple things that I thought of with your desciption
>>> was
>>> >> for
>>> >> >> > example
>>> >> >> > >>small focal subchorionic clot pulsating with maternal
>>> heart
>>> >> beat.
>>> >> >> > >>
>>> >> >> > >>Usually when I see something really strange on a first
>>> >> trimester
>>> >> >> > scan, I
>>> >> >> > >>would ask myself:
>>> >> >> > >>1) does bHCG correlate with the ultrasound findings?
>>> >> >> > >>2) does LMP correlate with the ultrasound findings?
>>> >> >> > >>3) does FH Rate correlate with CRL
>>> >> >> > >>
>>> >> >> > >>If I think I'm seeing a heartbeat, but I'm not entirely
>>> sure
>>> >> if it
>>> >> >> > may
>>> >> >> > >>be from maternal pulsation or embryonic in origin, a neat
>>> >> trick is
>>> >> >> > to
>>> >> >> > >>grab the patient's wrist and see if the embryonic
>>> heartbeat
>>> >> is
>>> >> >> > different
>>> >> >> > >>rate.  If not, it's probably transmitted pulsation from
>>> the
>>> >> >> > mother.
>>> >> >> > >>
>>> >> >> > >>I hope this helps. A set of images would be great.
>>> >> >> > >>
>>> >> >> > >>Yours,
>>> >> >> > >>
>>> >> >> > >>--
>>> >> >> > >>Martin Necas
>>> >> >> > >>RDMS, RVT
>>> >> >> > >>
>>> >> >> > >>At Fri, 23 Aug 2002, Sharon Brown wrote:
>>> >> >> > >>>
>>> >> >> > >>>I need info if posible.  Last week I was sent a patient
>>> from
>>> >> the
>>> >> >> > ER, in
>>> >> >> > >>>which the doc told the woman that he found fetal heart
>>> >> tones.  I
>>> >> >> > did a
>>> >> >> > >>>transvag and found a gestational sac with a yolk sac
>>> >> within.
>>> >> >> > However,
>>> >> >> > >>>hard as I looked I couldn't find a fetal pole.  As I was
>>> >> scanning
>>> >> >> > the
>>> >> >> > >>>uterus I found what the doc was talking about.  The
>>> problem
>>> >> is
>>> >> >> > that the
>>> >> >> > >>>fetal pole that I found was outside of the gestational
>>> sac
>>> >> and it
>>> >> >> > did
>>> >> >> > >>>have heart motion, it was also hyperechoic.  I am
>>> >> completely
>>> >> >> > baffeled by
>>> >> >> > >>>this, and the Rad that I showed the images and talked
>>> with
>>> >> >> > couldn't
>>> >> >> > >>>quite figure it out either.  How is it possible that a
>>> fetus
>>> >> can
>>> >> >> > reach
>>> >> >> > >>>the 6-7 week stage outside of the gestational sac, and
>>> what
>>> >> would
>>> >> >> > cause
>>> >> >> > >>>it to implant outside of the endometrious, yet still
>>> within
>>> >> the
>>> >> >> > uterus.
>>> >> >> > >>>It was in the area where one would normally find a sub
>>> >> chorionic
>>> >> >> > bleed.
>>> >> >> > >>>The fetal pole and the yolk sac both measured 4 mm.  Any
>>> >> help
>>> >> >> > would be
>>> >> >> > >>>appreciated.  Thanks Sharon
>>> >> >> > >>
>>> >> >> > >--
>>> >> >> > >Thanks for your input.  Hopefully I will be able to speak
>>> with
>>> >> the
>>> >> >> > radiologist
>>> >> >> > >that read the scan.  He wanted to do some research and
>>> said
>>> >> he
>>> >> >> > would let me
>>> >> >> > >know what he found out.  The motion was too fast to be that
>>> of
>>> >> the
>>> >> >> > mother. The
>>> >> >> > >heart motion was discovered by the ER doc before referring
>>> >> the
>>> >> >> > patient to me.
>>> >> >> > >At first I thought he was mistaken because of the empty
>>> sac,
>>> >> >> > however when I did
>>> >> >> > >find what he was referring to I did my own testing and
>>> found
>>> >> heart
>>> >> >> > motion a
>>> >> >> > >posibility in the absence of anyother logical conclusion.
>>> I
>>> >> am not
>>> >> >> > an expert
>>> >> >> > >in ob and so far what I have seen has been pretty straight
>>> >> forward.
>>> >> >> >  I was unprepared
>>> >> >> > >for this finding. I will certainly let all know what it
>>> turns
>>> >> out
>>> >> >> > to be if possible.
>>> >> >> > >again thanks for your response.  Sharon
>>> >> >> > >
>>> >> >> > >I will try to get permission to upload a couple of images.
>>> At
>>> >> this
>>> >> >> > point I
>>> >> >> > >don't know what to think.
>>> >> >> > >
>>> >> >> >
>>> >> >> > --
>>> >> >> > art fougner, md
>>> >> >> > ich bin ein New Yorker
>>> >> >> >
>>> >> >>
>>> >>
>>> >> --
>>> >> art fougner, md
>>> >> ich bin ein New Yorker
>>> >>
>>>
>>> --
>>> art fougner, md
>>> ich bin ein New Yorker
>>>
>
>--
>art fougner, md
>ich bin ein New Yorker
>


Peace, Terry J. DuBose, M.S., RDMS
Assistant Professor & Director, Diagnostic Medical Sonography Program
University of Arkansas for Medical Sciences, CHRP
4301 West Markham St. Mail Slot #563
Little Rock, Arkansas, 72205 USA
501-686-6510
DuBoseTerryJ@UAMS.edu
http://www.io.com/~dubose/
http://www.uams.edu/CHRP/dmshome.htm
http://www.obgyn.net/us/panel/panel.htm



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