|
|
 |
 |
 |
|
|
|||
|
||||
|
||||
Re: AFIFrom: Terry J DuBose (tjdubose@juno.com)Sat Sep 4 09:40:55 1999
Dr. Antony. Some prefer one method over the other. There is some subjectivity in all methods of estimating the amniotic fluid. The measurement of the single largest pocket or the sum of the 4 quadrants (AFI) method are both attempts to remove the subjectivity by quantification. However, even with these measurement methods, the exact placement of the cursors is quite variable in observer to observer, fluid pocket to pocket, and pregnancy to pregnancy. However, it does give one a "number", even if variable. Early in sonography (1977, Yale Un iv.) there was an attempt to estimate the fluid volume by measuring the volume of the uterus, but this was also variable. In 1987, Phelan, et al, published the AFI (Phelan, Ahn, Smith, Amniotic fluid index measurements during pregnancy. J Reprod Medicine 1987, 32:601-604). This method calls for measuring the largest vertical pocket (clear of umbilical cord, fetal extremities, etc) of amniotic fluid in four quadrants of the uterus (divide the uterus sagittally and transversely into 4 quadrants). The sum of the 4 vertical measurements is the AFI. As a general rule the AFI should be between 5 & 22 centimeters throughout pregnancy. The AFI will vary normally, increasing during the first half, then a very slow decrease in the second half. The largest AFI is usually found during the 22-28th weeks. I have a graph of this change with +/- 2SD in FETAL SONOGRAPHY, W. B. Saunders, 1996, p. 373. Sepulveda, Flack, & Fisk, using an infusion method in severe oligohydramnios and anhydramnios pregnancies, found that the AFI (4-quadrant sum) was more accurate than the single pocket method (Am J Obstet Gynecol 1994, 170:1160-1163). However, Goldstein & Filly (J Ultrasound in Medicine 1988; 7:363-369) found that in experienced hands a subjective assessment of fluid quantities was just as good as the measurement methods. In the subjective assessment the observer, as they are doing the sonograms, decides "This looks like too much, too little, or just right amounts of fluid." This subjective assessment does require quite a bit of experience, but does seem to be as good. Hope this helps. Peace, Terry J. DuBose, M.S., RDMS Little Rock, Arkansas USA ----------------------------------------------- On Sat, 4 Sep 1999 00:37:13 -0500 "DR.JOE ANTONY" <jscan@vsnl.com> ----------------------------------------------- writes: -- ----------------------------------------------- > Is amniotic fluid index an outdated technique? > Referring some articles on medline- largest single pocket has > replaced AFI- is that true? > One referring doc insisted on AFI-- I have no literature describing > the method. > Do you take the total of all four quadrants in cms? or is the > average of largest pockets taken-- > ie: divided by 4? Please describe exactly how to estimate AFI. > Regards, DR.JOE ANTONY
|
|
Return to
|
Mail a New Message to the Forum: ultrasound@obgyn.net Forum Administrator: terry.dubose@obgyn.net Report Technical Problems: webmaster@obgyn.net Last Updated: Wed Dec 2 05:35:32 2009 |
The American Medical Association is no longer designating CME hours for AMA Category II CME credit. However, physicians themselves may self designate learning activities as Category II CME credit hours if they feel it is of sufficient educational merit and meets the formal definitions of continuing medical education. OBGYN.net believes these interaction in this forum meets these criteria. For further information see the AMA web site.