New applications of conventional and Doppler sonography in pediatrics

Sonography is assuming an increasingly dynamic role in pediatric diagnosis. The small size of the patient and the use of short-focus, higher frequency transducers, coupled with continuous improvement in sonographic equipment, provide remarkably detailed images. The introduction of Doppler technology has catapulted sonography from the realm of purely anatomic information to that of physiologic and angiographic data. In neurosonography, there has been refinement of the nomenclature, quantification, and prognosis of intracranial hemorrhage and ischemic disorders. Doppler technology has helped us in understanding the vascular dynamics that occur after acute interruption of right internal carotid flow in patients who undergo extracorporeal membrane oxygenation. In abdominal diagnosis, sonography is also playing an increasingly important role in assessing both gastrointestinal and renal conditions. This review outlines some of the important concepts underlying pediatric sonography today and reviews some salient contributions of recent literature.     

Comparison of morning versus afternoon cecal intubation rates

Background  

Many factors impacting cecal intubation rates have been examined in detail; however, little information exists regarding the effect of the timing of the procedure. We sought to examine any difference in cecal intubation rates between morning and afternoon colonoscopies and identify factors contributing to a discrepancy.     

Transvaginal color duplex sonography: clinical potentials and limitations.

This overview describes our preliminary experience in the application of transvaginal color Doppler sonography in evaluation of the uterus and ovaries. The main indications for this type of sonography include evaluation for ovarian torsion, differentiation of benign from malignant ovarian masses, diagnosis of pelvic congestion, and assessment of utero-ovarian perfusion. Obstetric applications include evaluation of complicated early pregnancy and evaluation of placental disorders such as placenta accreta. No doubt future applications will arise soon from active investigation with this new technique.     

Three-dimensional color Doppler sonography and uterine artery arteriography of fibroids: assessment of changes in vascularity before and after embolization.

OBJECTIVE: To assess the accuracy of three-dimensional color Doppler sonography and uterine artery arteriography in depicting changes in fibroid vascularity before and after embolization. METHODS: Preembolization and postembolization three-dimensional color Doppler sonography and selective uterine artery arteriography were retrospectively compared in 15 patients who underwent uterine artery embolization for treatment of symptomatic fibroids. Three-dimensional color Doppler sonography was performed by using a scanner with color power angiographic imaging capability. Vascularity was quantified by using an estimation of power-weighted pixel density as described by our group in previously published studies. Uterine artery arteriography was performed by using a standard selective microcatheter embolization technique. For purposes of comparison, fibroids were classified as either hypervascular or hypovascular relative to myometrial vascularity before and minutes to several hours after uterine artery embolization. Changes in fibroid vascularity (i.e., from hypervascular to hypovascular) as depicted by three-dimensional color Doppler sonography were compared with those shown on uterine artery arteriography and classified as being in agreement or disagreement. RESULTS: In 13 (87%) of 15 patients there was agreement; in 2 (13%) of 15 there was disagreement. In both cases of disagreement, three-dimensional color Doppler sonography showed collateral flow not depicted by uterine artery arteriography The mean reduction in quantitated vascularity after uterine artery embolization was 44% (range, 19%-78%). CONCLUSIONS: Three-dimensional color Doppler sonography accurately depicts fibroid vascularity and in some cases can reveal collateral flow not depicted by uterine artery arteriography.     

Prospective evaluation of complications in an endoscopy unit: use of the A/S/G/E quality care guidelines.

In 1989, the American Society for Gastrointestinal Endoscopy released a quality assurance monograph in which a procedure review process was outlined. The major elements of the program for quality assurance in gastrointestinal endoscopy included: (1) procedure reports, (2) an endoscopic unit record, and (3) a procedure review. This study was designed to use the procedure review process to determine the incidence of complications, to identify quality assurance issues, and to determine whether audits and/or studies would result from this process. To make a meaningful interpretation as to what constitutes an important complication, a classification to define potential problems was established. Using this classification, a complication was identified in 64 of 3287 procedures (1.9%). These complications were discussed in a monthly morbidity and mortality conference. Additionally, 21 quality assurance issues were identified that led to four studies addressing these quality assurance issues.     

Elevated alpha-fetoprotein and a normal fetal sonogram: association with placental abnormalities

This report documents the outcome of 25 pregnancies with elevated serum alpha-fetoprotein levels on two separate samplings despite normal anatomic appearance of the fetus on a detailed "consultative" sonographic examination. Six of these also had elevated amniotic fluid alpha-fetoprotein. All fetuses in this series were anatomically normal at time of delivery; one aborted fetus was triploid. Of the 25 pregnancies, 16 had sonographically demonstrable placental hemorrhage, eight retroplacental and eight subchorionic. One had hydropic changes in the placenta associated with triploidy. Of the subgroup of six pregnancies in which both serum and amniotic fluid values were elevated, one had a retroplacental hemorrhage, one had a subchorionic hemorrhage, and one had diffuse hydropic changes in the placenta. A control group of 112 patients with normal alpha-fetoprotein levels yielded four with small (less than 2 cm3) subchorionic hemorrhage. The occurrence rate of placental hemorrhage in women with elevated alpha-fetoprotein and normal fetus was 64%, whereas the control group of patients with normal alpha-fetoprotein had a 3.6% occurrence rate of placental hemorrhage. Sonographically detectable placental abnormalities may be associated with elevated alpha-fetoprotein in serum and/or amniotic fluid samples. Such abnormalities may occur because of fetomaternal admixture associated with placental hemorrhage and/or intraamniotic bleeding resulting from subchorionic hemorrhage.     

Expression of CD83 in the murine immune system

CD83 is used as a marker for mature dendritic cells (DC) in man. We have developed a new monoclonal antibody (mAb), Michel-17, that specifically recognizes mouse CD83. We show that murine CD83 is expressed mainly on mature DC and on activated T cells. Histological analysis of serial spleen sections revealed a CD83 expression pattern resembling that of MIDC-8, a known murine DC marker molecule. In contrast to other costimulatory receptors, cross-linking of CD83 with the mAb Michel-17 on DC or T cells does not induce any activation signals. Our data describe for the first time the expression pattern of murine CD83, which is comparable to that of human CD83.The unique mAb Michel-17 will help to elucidate the biological functions of the CD83 molecule in more detail.