Terry J. DuBose

Embryonic Heart Rate and Age

This study used linear regression analysis to show that embryonic heart rate (EHR) can be used in the clinical setting to provide an estimate of embryonic age that correlates well with the fetal crown-rump length age (CRL; r = 0.856). A regression was performed on data from 275 examinations in which an embryonic heart rate was recorded before the ninth menstrual week from a cross-sectional population of 1,136 examinations throughout pregnancy. In this analysis, EHR was used as the independent variable and CRL as the dependent variable to yield the following formula for CRL age in menstrual days: CRL Age (menstrual days) = 8.18 + 0.285 EHR. Based on this result, a rounded version of the formula was sought that would provide essentially the same estimated fetal age as the regression formula for the range of EHR that occurred in the sample (84-193 beats/min) yet allow for a simpler computation. Within that range of EHR, the following clinical versions of the regression formula were found to produce results that did not differ significantly from the original formula: Days of Gestation = 0.3 EHR -8 and Menstrual Days Age = 0.3 EHR + 6. Both the original regression and the clinical versions yielded 95% prediction intervals of approximately ± 8 days across the range of EHR that occurred in the sample. While fetal age based on this method is only an approximation of the CRL age, the heart rate can be obtained using time/motion mode sonography when only the less accurate gestational sac diameters are available. The EHR is useful to corroborate early age estimates, especially when using transvaginal transducers and may provide useful information concerning cardiac development.

Confusion and Direction in Diagnostic Doppler Sonography

Spectral and color sonographic Doppler information has become critical to medical imaging and diagnosis. However, there are no standards for the display of the Doppler frequency-shifted sonographic directional information. The display of the spectral and Doppler directional information is arbitrary and under operator control. The authors discuss the current situation of the Doppler directional displays and the problems that may be caused by this confusion.

Fetal Biometry: Vertical Calvarial Diameter and Calvarial Volume

This paper proposes a method of approximating the fetal calvarial volume (CV) by measuring the vertical calvarial diameter in addition to the biparietal diameter and the fetal long skull diameter. The methods of measurement and calculation are discussed, and graphic analysis is presented. The approximate CV and the sum of the three fetal skull diameters (3D) correlate well with fetal gestational age regardless of individual variations in fetal skull shape and normal molding. Two least squares regressions for estimating fetal ages from the CV and 3D are given. Three cephalic indices in the transverse, sagittal, and coronal planes are also discussed.

Sonography of arcuate uterine blood vessels.

Five sonographic cases are presented with images that demonstrate normal arcuate arteries and peripheral uterine blood vessels. These vascular structures are shown in both the longitudinal and transverse sections, and should not be confused with pathology such as Nabothian cysts, hydrosalpinx, pelvic inflammatory disease, hydatid cysts of Morgagni, endometriosis, or abnormal pelvic varices.

Re: Fetal brain/liver volume ratio and umbilical volume flow parameters relative to normal and abnormal human development

Boito, Struijk, Ursem, Fedele and Wladimiroff1 are commended for their forward looking article concerning the fetal brain/liver volume ratio and perfusion as they relate to growth and well-being. This complex analysis does point in the direction that sonography needs to go in order to better assess fetal health. The authors are encouraged to continue their research. It will be interesting to see their results in a larger population, and hopefully they will publish regression formulas for all their parameters. This approach may be useful in the assessment of fetal infections in which the liver and/or spleen are often enlarged. The infected fetus is ill and may be truly growth-restricted with an abdominal/head circumference ratio which may appear normal due to the diminution of subcutaneous fat but increased liver/spleen sizes. However, their use of a fetal brain volume that was estimated from the transverse head circumference was frustrating, especially since they used actual volumetric measurements for the liver. To use the transverse head circumference for volumetric estimations ignores the change in the vertical cranial diameter (VCD) with molding and abnormal head shapes; ‘VCD is the most dynamic diameter and most sensitive to these changes in skull shape’2,3. While their methods may be valid for the estimation of the mean head volume in a large, normal population, their estimations would exhibit less variation, especially near term, if true three-dimensional measurements were used for the volume. The fetal head does not exist in ‘Flat Land’ and due to the arrangements of the sutures and fontanels, often head molding will exaggerate the VCD in dolichocephaly, and brachycephaly will result from compression of the vertical axis as the fetus presses its head against the uterine wall or pubic symphysis. True volumetric measurements should result in greater sensitivity for their methods4,5. The estimation of volumes from the biparietal diameter or transverse head circumference will be relatively accurate in normally shaped heads; however, if molding and abnormal head shapes are an issue, then one diameter or a circumference in a single plane are not enough for the greatest accuracy. To illustrate, the following analysis of variance (Table 1), and histograms (Figure 1) represent 6845 of 10 296 cases, in which all three diameters were measured and the age by last menstrual period was > 10 gestational weeks. The histograms are ratios of each diameter divided by the average of the three diameters for each case. Note Table 1 Analysis of variance (ANOVA) of the three-dimensions index (3d) of the fetal cranium

Sonographic Correlation of Fetal Heart Rate and Gender

This study sonographically evaluates the fetal heart rate throughout gestation and the babys sex at birth to determine if the fetal heart rate is an indicator of the babys sex. The results of the evaluation of 365 cases indicates that the fetal heart rate is not an accurate indicator of fetal sex.

Electronic Systems for Student Clinical Records

Proper documentation of a student’s clinical education is a critical component of a diagnostic medical sonography program’s administrative functions. Traditional paper documents have been used for decades to record and verify a student’s clinical training. However, these paper records can rapidly become a paperwork nightmare, especially for large sonographic programs spread over a broad geographical area. This article examines the reasons for keeping accurate clinical records, discusses paper clinical records systems, and reviews some of the new electronic systems for student clinical records that are now emerging in the allied health professions.

Crystallography and the Gene Helix Discovery An Interdisciplinary Educational Project

This interdisciplinary project was designed to give students of radiography and sonography a basic understanding of x-ray diffraction in crystallography, the dual nature of electromagnetic radiation, and the Human Genome Project. As a secondary result of the project, questions concerning the attribution and polemics of research publication arose, so this discussion is also included. This latter issue, involving Rosalind Franklin’s contributions to the study of human genetics, is particularly interesting to radiographic technologists and diagnostic sonographers because images that they produce continue to be published without any attribution or acknowledgment of their contribution.

OBGYN.net and Sonography

TERRY J. DUBOSE, MS, RDMS, FSDMS, FAIUM Most sonographers are technophiles. In general, people who become sonographers are not afraid of technology or computers. For this reason alone, it is not surprising that sonographers and sonologists have flocked to use the Internet and the World Wide Web for education, consultations, and communications with colleagues around the world. The number of people using the Internet is increasing rapidly worldwide, and medical Web sites are increasing exponentially. The World Wide Web is a graphic mode of communications, and it is natural that ultrasound images would be exchanged and discussed via this new medium. This article will be a brief review of the history, uses, and contributions of OBGYN.net to ultrasound. Before the World Wide Web was invented, many medical professionals around the world had begun to communicate via e-mail and list servers or discussion groups. The earliest list for OB-GYN discussion was OBGYN-L, established in 1995 by Dr. Geffrey Klein while he was a resident at Baylor School of Medicine in Houston. While a graduate student in 1994-1996, I was a subscriber to OBGYN-L and the first sonographer participant. In 1996, OBGYN-L went onto the Web as OBGYN.net, and the power of the Web for sharing visual information such as sonograms was obvious. I suggested that an Ultrasound Section was the natural evolution of the electronic medium, and Ultrasound@OBGYN.net was born in November 1997. The Ultrasound@OBGYN.net discussion forum is for health care professionals using sonography in women’s health and includes some of the luminaries of ultrasound worldwide. I believe that this is one of the highest and best uses of the World Wide Web in medicine. The ability to quickly display images and get responses from many experts around the world is a remarkable advancement in world health. However, I must caution that to give a second opinion longdistance is not necessarily good medicine. While we can be enthusiastic about this new medium, the physician managing the case must remain in control 120 JDMS 17:120–121 March/April 2001

ARDMS OB/GYN Task Analysis Results:

The American Registry for Diagnostic Medical Sonographers (ARDMS) administers credentialing examinations for individuals in specialties in medical sonography and vascular technology. The ARDMS is a member of the National Commission of Certifying Agencies, which accredits certifying organizations, as well as being accredited by the American National Standards Institute (ANSI) and the International Standards Organization (ISO). Part of the requirement of the certifying agencies is that the examinations reflect current practices in each of the specialty areas. To fulfill this requirement, the ARDMS performs a task analysis of each specialty examination every five years. The survey covers each content area of the certifying examination and the content outline is revised to reflect any changes in the current practice of the specialty. The examination blueprint is the revised outline which ARDMS provides for their OB/GYN examination candidates. (See appendix at the end of this article.)