Spontaneous involution of neonatal adrenal neuroblastoma detected by sonography

Abstracts Conclusions: It was concluded that the ultrasound examination is a fundamental tool in preventive medicine, being demonstrated through the results obtained. 32809 Prenatal ultrasound for the detection of chromosomal abnormalities Smith-Bindman R,*1 Currier B,2 Quale C,1 Roberson M,2 Cunningham G,2 1. Radiology, Epidemiology, and Biostatistics, University of California at San Francisco, San Francisco, CA, and 2. Genetic Disease Branch, CA Department of Health Services, Berkeley, CA Objective: The aim of this study was to assess the accuracy of ultrasound for detecting Down syndrome (DS) fetuses. Methods: Approximately 75% of California gravidae undergo serum biochemical screening (350,000 women/year) through the state-administered California Maternal Serum Expanded AFP program. All women who test positive on serum screening are offered an amniocentesis and ultrasound. Between November 1999 and January 2001, women with a positive DS screening test (mid-trimester risk ⬎ 1/190) were referred to one of 29 perinatal diagnostic centers for further evaluation, and we obtained and analyzed ultrasound results for these women using a standardized data collection form. Pregnancy outcomes were obtained through a surveillance system that requires physicians to complete a pregnancy outcome form on all women who tested positive on serum screening, as well as California state-required reporting of chromosomal abnormalities by cytogenetic laboratories. Results: Ultrasound results were collected for 19,415 women who had elevated risk of DS, trisomy 18, or neural tube defect. Overall, 14.7% of women had an abnormal ultrasound examination, based on a suspected structural abnormality or a DS marker. Prevalence of DS markers was similar to that reported in other high-risk populations, including choroid plexus cysts (n⫽363, 1.9%), mild ventriculomegally (n⫽66, 0.3%), nuchal fold thickening (n⫽211, 1.1%), echogenic intracardiac focus (n⫽509, 2.6%), echogenic bowel (N⫽193, 1.0%), renal pyelectasis (n⫽292, 1.5%), and two-vessel umbilical cord (n⫽106, 0.6%). The prevalence of structural anomalies also reflects the high-risk nature of these women: anencephaly (n⫽106, 0.6%), spina bifida (n⫽92, 0.4%), cystic hygroma (n⫽88, 0.4%), cleft lip or palate (n⫽44, n⫽0.2%), cardiac defect (n⫽169, 0.9%), abdominal wall defect (n⫽143, 0.7%), and renal agenesis (n⫽18, 0.1%). Approximately 240 cases of DS, 30 of trisomy 18, and 260 cases of other chromosomal abnormalities will have been diagnosed among these women. Conclusions: We are currently linking the serum screening, ultrasound, and pregnancy outcome data. We will quantify how prenatal US can augment risk assessment for chromosomal abnormalities after serum screening. 32814 In vitro characterization of liposomes and Optison by acoustic scattering at 3.5 MHz Holland CK,*1 Coussios C,1 Jakubowska L,1 Huang S,2 MacDonald RC,2 Nagaraj A,3 McPherson D,3 1. Biomedical Engineering, University of Cincinnati, Cincinnati, OH, 2. Biochemistry, Northwestern, Chicago, IL, and 3. Cardiology, Northwestern, Chicago, IL Objective: To assess the potential of immunoliposomes as an ultrasound contrast agent relative to albumen-stabilized microbubbles, a quantitative assessment of echogenicity was performed. Methods: Liposomes are stabilized phospholipid vesicles, which can encapsulate both gas and fluid. With antibody conjugation, this new formulation of immunoliposomes can be targeted to atheroma and other

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pathologic components, and thus they are being developed as novel diagnostic ultrasound echo contrast agents to enhance imaging of atherosclerosis. The diameter of the liposomes ranges from 0.25 to 5.0 microns. To measure the backscattering coefficient of liposome suspensions of varying concentrations, the backscattered power at 3.5 MHz was compared to that reflected from a planar air-water interface. The backscattering coefficient was also estimated theoretically as a function of air volume fraction by modeling the encapsulated air as a free air bubble and assuming single bubble scattering. Results: For most of the concentrations of liposomes used (on the order 108/ml), the backscattering coefficient equals or exceeds that of Optison (Mallinckrodt, Inc.) at the human clinical dose concentration (104/ ml). The backscattering coefficient at 3.5 MHz appears to be a linear function of liposome concentration, suggesting that single bubble acoustic scattering theory holds. Conclusions: This detection technique shows promise as a sensitive method for determining whether the immunoliposomes are left intact or if they are destroyed during imaging, thus helping to explore their potential as a vehicle for targeted drug delivery. 32816 A description of a new artifact observed in ultrasound images of linear metallic objects Gorny K,* Tradup D, Hangiandreou N, Muller B, Gorman B, Radiology, Mayo Clinic, Rochester, MN Objective: We report an unusual artifact observed recently in clinical ultrasound (US) images obtained during a biopsy. We do not believe that this artifact has been previously described in the literature. The artifact appeared as a comet-like pattern of echogenic signal, which originated at the tip of the biopsy needle and emanated downward, simulating a rough mirror image of the needle. Experiments in test objects as well as numerical calculations were performed to explain the artifact appearance and establish the origin. Methods: A general explanation of the artifact is that it is due to a vibrational wave produced by initial incidence of the US pulse with the needle. This wave travels down the length of the needle, reflects off the needle tip, and travels back the length of the needle, ultimately producing a signal detected by the transducer and mapped into the US image. Experiments were performed to determine whether the wave traveling along the needle was shear or longitudinal in nature. The artifact was replicated in test objects consisting of strips of various metals including aluminum and copper, immersed in a water bath. Measurements of the incident angles, which produced the artifact, as well as the angle between the metal object and the artifact were made, and were compared with theoretical predictions. Results: We found that copper strips produced artifacts for incident angles between 14 and 62 degrees, and the artifact angles varied from 29 degrees and 35 degrees as a function of incident angle. Similarly, for aluminum strips, artifacts were observed for incident angles between 13 and 42 degrees, while the artifact angles varied between 20 degrees and 30 degrees. These results are reasonably consistent with a shear wave explanation. More definitive experiments are in progress. Conclusions: We describe a new artifact observed both clinically and in test objects that results from US waves traveling along the length of a needle or similar metal object. Although our quantitative measurements are not conclusive, it appears most likely that this artifact results from shear, rather than longitudinal waves. 32818 Spontaneous involution of neonatal adrenal neuroblastoma detected by sonography Felc Z, Neonatal Unit, General Hospital, Celje, Slovenia

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Objective: Possible spontaneous involution of untreated adrenal neuroblastoma in newborn infants is frequently discussed, but has very rarely been demonstrated clinically. Methods: We report five patients with adrenal neuroblastoma detected by ultrasound early in the Department of Obstetrics and Gynecology, Neonatal Unit, General Hospital, Celje, Slovenia. One patient was detected antenatally; the other four tumors were detected postnatally by routine renal sonography, performed on each of 17,705 consecutive newborns delivered throughout 9 years, ending December 31, 1998. All five patients were admitted to the Department of Oncology, University Children’s Hospital, Ljubljana, Slovenia. Results: During our screening, 5 cases of neonatal adrenal neuroblastoma (2 girls, 3 boys; four cases were right sided, one case was left sided) were noted at an incidence of 2.9 per 10,000. In all patients, treatment was delayed to await a possible spontaneous involution. Local tumor growth was observed in two patients, and the tumors were removed 12 and 16 weeks, respectively, after the initial diagnosis of neuroblastoma. Three of the five patients showed spontaneous tumor involution. All five patients are free of disease. Conclusions: In our study, overall spontaneous involution of adrenal neuroblastoma for newborn infants is 60%. Further studies are needed to confirm our speculation that ultrasound screening in newborn infants mainly detects adrenal neuroblastomas that would dissappear without any treatment. 32819 Ultrasonically enhanced optical coherence tomography of the retina and choroid Lloyd H,*1 Rondeau MJ,1,2 Silverman RH,1,2 Lizzi FL,3 Coleman DJ,1,2 1. Ophthalmology, WMC of Cornell University, New York, NY, 2. Dyson Vision Research Institute, New York, NY, and 3. Biomedical Engineering Directorate, Riverside Research Institute, New York, NY Objective: The aim of this study was to examine the ability of photon/ phonon interaction to reduce the effect of multiple scattering in clinical OCT images of the posterior pole of the eye and therefore improve resolution and reduce noise. Methods: A third-generation commercial ophthalmic OCT (ZeissMeditec OCT3) was used in conjunction with an ATL 7.5-MHz linear array or a single element unfocused 8-MHZ transducer as the experimental apparatus. The configuration of the OCT delivery optics precluded direct co-localization of the ultrasound and laser beams, but approximate focal distance along with a 10 to 15 degree ultrasound beam offset could be achieved. Healthy volunteers with clear media and no history of ocular disease were scanned with the combined ultrasound system. OCT data acquisition sequences were performed concurrently with CW and pulsed ultrasound protocols at intensities below FDA limits for ophthalmic examinations. Fourier and wavelet methods were used to estimate changes in OCT PSF during ultrasound exposure. Results: Statistically significant but small changes in mean PSF were seen for both CW and pulsed exposure for each ultrasound delivery system. Improvement was seen in spite of sub-optimal experimental parameters and the presence of the crystalline lens in the ultrasound path. Conclusions: The study demonstrates that concurrent diagnostic level ultrasound exposure can improve OCT resolution using commercially available equipment. The use of dedicated co-axial OCT/ultrasound transducers with frequency and excitation characteristics optimized to frequency shift multiple scattered light outside the range of detector’s bandpass filter could provide clinical significant improvements in system resolution without the use of expensive solid state lasers.

Volume 29, Number 5S, 2003 32820 Efficacy of fetal cardiac axis measurements as a screen for cardio-thoracic anomalies Egan JF,*1,2 Szjada B,2 Milewski E,2 Deroche M,2 Bolnick A,2 Borgida AF,2 1. Maternal-Fetal Medicine, St. Francis Hospital and Medical Center, Hartford, CT, and 2. Maternal-Fetal Medicine, University of Connecticut, Farmington, CT Objective: The aim of this study was to assess the efficacy of fetal cardiac axis measurements as a screening method for cardiac and thoracic cavity anomalies. Methods: We reviewed our prospectively collected obstetrical ultrasound database from 1/95 to 5/02 at 15–22 weeks’ gestation for cardiac axis measurements. The examination closest to 18.0 weeks’ gestational age was used if more than one was recorded. A cardiac axis measurement of 27 to 59 degrees was considered normal (Bork et al., AJOG 1998;179:982– 4). Cardiothoracic abnormalities were determined by targeted ultrasound and/or fetal echocardiography. Sensitivity (Sens), false positive rate (FPR), positive predictive value (PPV), and negative predictive value (NPV) were analyzed for cardiac and thoracic cavity anomalies. Results: Of the 17,021 pregnancies scanned during the study period, 3,880 had a cardiac axis recorded. Ultrasound images from March 2000 to May 2000 were searched for normal cardiac axis determination. Other measurements were exported from the database. Of the 3880 fetuses, 85 (2.2%) had an abnormal cardiac axis, and 40 (0.4%) had a cardiac or thoracic abnormality. The mean (⫾SD) normal cardiac axis was 44 (⫾7.1). Cardiac axis was independent of gestational age (R2 ⫽ 0.0063). The following anomalies were found: cardiac (n⫽33): ASD/ VSD (20), A/V canal (5), DORV (2), HLH/HRH (3), situs inversus (4), cardiomegaly (2), tetralogy of Fallot (1); thoracic cavity/lung (n⫽7): CCAM (3), diaphragmatic hernia (1), pleural effusion (3), and scimitar syndrome (1). Some fetuses had more than one anomaly. Conclusions: Cardiac axis measurement is gestational age independent and is an efficacious screen for cardiac and thoracic defects.

Cardiac Thoracic

Sens (%) 36.4 57.1

FPR (%) 1.2 1.6

PPV (%) 21 6

NPV (%) 99.5 99.9

32833 Acoustic streaming—An in vitro study Clarke L,*1,2 Edwards A,2 Graham E,2 1. Ultrasound Department, Monash Medical Centre, Clayton, VIC, Australia, and 2. Monash University, Clayton, VIC, Australia Objective: Acoustic streaming has been used in the clinical situation to help distinguish cystic from solid breast lesions (Nightingale et al, 1995 & 1999). In our clinical situation, we have seen particular types of ovarian cysts exhibit acoustic streaming. To make this observation useful, we need to establish the conditions in which a cyst will exhibit acoustic streaming. Therefore, our aims were to establish the variables that affect the presence of acoustic streaming; to identify the optimum parameters under which acoustic streaming is observed; and to establish how the viscosity of different fluids affects acoustic streaming. Methods: A Phillips ATL5000 ultrasound machine with a C8-4 transvaginal probe was used. A cyst was constructed using a condom filled with fluid and the probe and cyst were suspended in a tissue-mimicking (milk) bath. The variables that were studied included cyst size (3cm & 5 cm cysts), distance of the cyst from the transducer (1 cm, 2 cm, 3 cm), and fluids of different, known viscosities. These fluids included methanol, water, milk, olive oil, and glycerine. The observations made included the presence of streaming in B-mode and colour Doppler