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From 1978 to 1990, 263 fetuses with an elevated level of amniotic fluid alpha-fetoprotein (AF-AFP) (> 2.0 multiples of the median) were examined with targeted fetal sonography. All cases of AF-AFP elevation among 22,355 genetic amniocenteses were represented. Sonography correctly showed 32 open neural-tube defects, including 20 myelomeningoceles, and depicted 94% (63 of 67) of the anomalous fetuses. Two of five anomalous fetuses with normal sonograms, however, had extremely high AF-AFP levels leading to prospectively correct diagnoses of congenital nephrosis. Therefore, programmatically, 97% (65 of 67) of the anomalous fetuses were recognized. The three programmatic misdiagnoses were all detected in the neonatal period and surgically corrected; subsequent development was normal. The combination of an elevated AF-AFP level and a detailed sonogram allowed distinction between a normal and an anomalous fetus in 99% of cases. When elevated levels are noted, AF-AFP analysis followed by detailed sonography is hi...

To evaluate the impact of endovaginal (EV) sonography in the diagnosis of ectopic pregnancy, a 2 year retrospective study was performed identifying 123 at-risk patients. Of these 123 women, 19 (15.4%) had a surgically proved ectopic pregnancy, only three (15.8%) of which were visualized directly at sonography. A confident diagnosis of an intrauterine pregnancy (IUP) was made at the initial scan in 74%, which contrasts with 58% diagnosed at the first transabdominal (TA) scan in an earlier study from this laboratory, thus confirming an improvement in diagnostic ability with EV transducers. This study has failed to confirm some findings of other workers, particularly that adnexal ring-like structures are visualized frequently in the presence of an ectopic pregnancy. No adnexal rings were observed in our 19 cases. The combination of an adnexal mass and free pelvic fluid was found to correlate best with the presence of an ectopic pregnancy. This study further emphasizes that a significant proportion (26.3%) of ectopic pregnancies have a normal EV sonogram at presentation. The group failing to demonstrate an IUP and showing no evidence of an adnexal mass or pelvic fluid (i.e., a normal pelvic sonogram) carried a 1:3 risk for the presence of an ectopic pregnancy, a result that is very similar to our data published before the introduction of EV technology. We conclude that, although it provides a significant improvement and refinement in the recognition of intrauterine pregnancies, EV scanning does not permit a confident diagnosis of ectopic pregnancy in many cases.

The sonograms and case records of 53 patients with prenatally detected myelomeningoceles were retrospectively reviewed. Sonographic findings were correlated with pathologic, surgical, and/or radiographic findings in 28 cases. Fourteen mothers chose to continue their pregnancies, and the level of neuromotor deficit was available for 11 children of this group. The sonographic and pathologic levels were in agreement in 18 of 28 cases (64%) and were within one spinal level in 22 of 28 cases (79%). The pathologic level of the lesion was underestimated (sonographic level lower than pathologic) in three fetuses and overestimated (sonographic level higher than pathologic) in another three. In 10 of 11 living children (91%) the neuromotor level was equal to or better than the anatomic level. The authors conclude that ultrasonography can, in most cases, allow accurate prediction of the level of the spina bifida lesion and the severity of neuromotor handicap in children with prenatal diagnoses of myelomeningocele.

An inability to image the kidneys, severe oligohydramnios, and an empty (nonvisualized) urinary bladder are the most common sonographic findings in fetuses with renal agenesis. The same features, except for the oligohydramnios, are seen in neonates with renal agenesis. Failure to visualize a kidney in the usual flank location with or without demonstration of the kidney in an ectopic location may also be a feature in fetuses or neonates with renal ectopia. The adrenal gland has an unusual but distinctive appearance on longitudinal sonograms in these patients. Sonograms of 23 fetuses and six neonates referred for presumed bilateral or unilateral renal agenesis or ectopia were reviewed retrospectively for the presence of a flattened ("lying down") adrenal gland. At the time of the examination, the adrenal gland was not actively sought as a part of the fetal survey or postnatal examination but was found retrospectively in 48% of these subjects. Although this finding has been described previously, the emphasis was on this observation as a potentially confusing sonographic feature. This manuscript emphasizes the characteristic appearance of the adrenal gland which instead serves as a simple means of confirming that the kidney did not develop in the flank. Detection of a flattened ("lying down") adrenal gland is an observation that should be actively sought in all fetuses and neonates with a presumed diagnosis of renal agenesis or ectopia.

To evaluate the observation that fetuses with omphaloceles containing only bowel have an especially high prevalence of karyotypic abnormalities, we retrospectively reviewed the sonograms and case records of 37 fetuses with omphaloceles detected sonographically between 1984 and 1990. Nine fetuses had concomitant morphologic abnormalities characteristic of the amniotic band syndrome. Of the remaining 28 fetuses, karyotypic correlation was available in 22, and the karyotype was abnormal in five of these (23%). The omphaloceles contained liver in 22 fetuses and only bowel in six fetuses. Among fetuses with exteriorized liver, karyotypes were abnormal in one (6%) of 16 tested. In contrast, four (67%) of the six fetuses whose omphaloceles contained only bowel had abnormal karyotypes; for each of these four, sonograms showed morphologic abnormalities in addition to the omphalocele. In the two fetuses with bowel-only omphaloceles and normal karyotypes, the omphalocele was the only abnormality seen on sonograms, and these children are well after surgical repair. When fetuses with the amniotic band syndrome were excluded, sonograms showed concomitant anomalies in 15 fetuses with liver-containing omphaloceles, and the karyotype was abnormal in only one of these 15. The results of this study support previous observations that karyotypic abnormalities are more common in association with omphaloceles that contain only bowel compared with those that contain only liver. If we combine our data with data from three other studies that address this issue, 87% of fetuses with omphaloceles containing only bowel had an abnormal karyotype, a significantly higher rate than in those fetuses whose omphaloceles contained liver also (9%).

Sonograms of fetuses at risk for congenital lethal osteogenesis imperfecta (osteogenesis imperfecta type II) were retrospectively reviewed blindly and correlated with pregnancy outcomes. Six of eight cases of type II osteogenesis imperfecta were correctly diagnosed with use of the proposed criteria of multiple fractures, demineralization of the calvaria, and femoral length more than 3 standard deviations below the mean for gestational age. The two cases not diagnosed had sonographic abnormalities but did not meet all three criteria. Among 18 pregnancies genetically at risk for the disease but with normal outcomes, all sonograms were normal, meeting none of the proposed criteria. Among an additional 25 fetuses with osteochondrodysplasias, no case satisfied all three of the proposed diagnostic criteria. With use of strict standards for the diagnosis of type II osteogenesis imperfecta, this disease can be distinguished from other fetal skeletal abnormalities. In a pregnancy at risk for recurrence of osteogenesis imperfecta, a normal sonogram after 17 weeks excludes this lethal condition.

Sonograms and radiographs of the lumbar spine in 51 fetuses and neonates with thanatophoric dwarfism, achondroplasia, and osteogenesis imperfecta type II were retrospectively evaluated. Study data included 27 prenatal and 27 neonatal sonograms and radiographs in 40 fetuses and neonates and 11 cases described in the radiology literature. To precisely compare the sonographic and radiographic appearances of platyspondyly in dysplasia, a simple vertebral ratio was obtained from measurement of vertebral interspace and vertebral body height. Normal ranges were obtained from sonograms in 125 normal fetuses and from radiographs in 55 normal fetuses. The severe platyspondyly of thanatophoric dysplasia and the milder platyspondyly of achondroplasia were detected by about 20 menstrual weeks. The vertebral bodies appeared slightly larger on sonograms than on radiographs in both normal fetuses and fetuses with dysplasia.

To evaluate the reliability of sonographic lung-to-head ratio (LHR) measurement as a predictor of survival in fetuses with congenital diaphragmatic hernia (CDH) and to compare the probability of survival in those with temporary tracheal occlusion (TO) or standard care with respect to the LHR.Fifty-six fetuses with left CDH with liver herniated into the thorax at complete prenatal evaluation were included in logistic regression analyses of antenatal predictors of survival to hospital discharge. Sixteen subjects underwent TO and 40 received standard care.LHR was a significant predictor of survival, with probability of survival increasing with increasing LHR (odds ratio (OR) 8.5, P = 0.04). When subjects with anomalies were excluded, the LHR effect was similar after adjustment for TO (OR 7.1, P = 0.11). Linear spline models suggested a plateau in survival at an LHR of 1.0 and all models suggested increased odds of survival with TO. Minimum LHR measurements had a high degree of inter- and intraobserver agreement (intraclass correlation coefficients of 0.70 and 0.80, respectively).Calculation of the LHR in fetuses with CDH is a reliable and powerful predictor of survival to hospital discharge, although improving odds of survival may plateau at an LHR of 1.0. TO may have an independent benefit on survival to hospital discharge.

Despite advances in postnatal care, patients born with a congenital diaphragmatic hernia (CDH) suffer substantial morbidity and mortality. The present study was undertaken to determine the prognostic influence of prenatally-diagnosed liver herniation in the hemithorax in fetuses with CDH. The medical records of 48 patients evaluated for a prenatally-diagnosed left CDH were retrospectively reviewed. Patients were analysed according to the position of the liver by prenatal ultrasound; 32 fetuses had a major portion of the liver herniated into the left hemithorax ('liver up') and 16 had an intra-abdominal liver ('liver down'). Liver position was determined using colour-flow Doppler ultrasonography. There were two fetal deaths in the liver-up group and one in the liver-down group. The liver-up group more frequently required extracorporeal membrane oxygenation (ECMO) support (53 per cent) compared with the liver-down group (19 per cent). Postnatal survival was significantly less in the liver-up group (43 per cent) vs. the liver-down group (93 per cent). Fetuses with congenital diaphragmatic hernia and liver herniated into the hemithorax have a much worse prognosis than similarly afflicted fetuses without liver herniation. Prenatal ultrasonographic diagnosis of congenital diaphragmatic hernia allows for preparation for a critically ill newborn and aids in prenatal family counselling.

Ultrasound has been found to be extremely accurate in diagnosing the chorionicity of multiple gestations. Prenatal counselling and/or planning for selective termination is most often based on the sonographic prediction of chorionicity. We present a case of triplet pregnancy in which early sonographic prediction of chorionicity did not match the pathological diagnosis at delivery.

Fetal chest masses are rare lesions that can be detected on prenatal sonography. This report of three cases of bilateral fetal chest masses (two bilateral congenital cystic adenomatoid malformations of the lung and one case of bilateral pulmonary sequestrations) serves to emphasize the occasional occurrence of bilateral masses and the variability in prognoses.

The aim of this study was to generate quantitative data regarding technical and analytical time savings obtained by use of an ultrasonographic PACS. Data/time cards were recorded for each patient encountered in an outpatient diagnostic ultrasound facility for a 4 week period immediately before and a 1 year period after installation of a PACS environment. Use of a sonographic PACS resulted in a per case time savings of 293 s in the technical component and 51 to 63 s in the analytical component of an average ultrasonographic examination. We conclude that use of a PACS workstation has the potential to increase productivity for both the sonographer and the radiologist.

Managing a pregnant patient with a suspected nonobstetric abdominopelvic disorder is challenging. Information from imaging affects the treatment options, which range from operating emergently and risking miscarriage to terminating the pregnancy or delaying treatment until after delivery. The most common indications for MR imaging during pregnancy are disorders of the central nervous and cardiovascular systems. In the evaluation of the abdomen and pelvis, sonography plays the pivotal role; however, sonography may be inconclusive because of its limited specificity in tissue characterization and technical difficulties caused by the enlarged uterus. For these reasons MR imaging has emerged as a valuable adjunct to sonography. In this pictorial essay we describe a variety of nonobstetric abdominopelvic disorders during pregnancy in which MR imaging contributed to patient management.

This study was performed to evaluate the efficacy of the American Institute of Ultrasound in Medicine/American College of Radiology guidelines for the detection of fetal abdominal abnormalities. In Part 1 of the study, images from 100 fetuses with sonographically diagnosed abdominal anomalies were masked except for one view of the abdominal circumference, stomach, renal area, bladder, and cord insertion. Ninety-six cases were recognized as abnormal by two sonologists. In Part 2, sonograms of 70 normal fetuses and 30 abnormal fetuses were similarly masked and shown to a sonographer and a fourth year radiology resident. Each identified 29 of 30 abnormal cases. Among fetuses with abdominal anomalies detectable at a prenatal diagnostic center, the majority of abnormal fetuses could be identified by evaluation of the five AIUM/ACR recommended views.

To compare the prognoses for fetuses with sonographically detected inferior vermian agenesis (IVA) or complete vermian agenesis (CVA).The sonograms of 65 fetuses with Dandy-Walker malformations were retrospectively reviewed. Fetuses were divided into two groups--those with IVA and those with CVA.Of the 65 fetuses, 37 had IVA; 28, CVA. Thirteen (20%) of the 65-nine (24%) of the 37 with IVA and four (14%) of the 28 with CVA--lived for longer than 1 year. Chromosomal abnormalities were found in 23 (45%) of the 51 fetuses tested for karyotypic abnormalities or clinically thought to have Down syndrome. Seventeen (53%) of the 32 with IVA and six (32%) of the 19 with CVA that were tested for karyotypic abnormalities or clinically thought to have Down syndrome had chromosomal abnormalities (P = .07). Associated morphologic abnormalities were prenatally detected in 49 (75%) of the 65-in 28 (76%) of the 37 with IVA and in 21 (75%) of the 28 with CVA.The overall guarded prognosis is similar for fetuses with Dandy-Walker malformations for whom IVA or CVA has been sonographically diagnosed. Fetuses with IVA have a higher prevalence of karyotypic abnormalities.

Teratogen exposures cause 1-2% of congenital abnormalities. Our anecdotal experience was that detailed fetal sonograms conducted for the indication of teratogen exposure failed to demonstrate significant morphological abnormalities. We reviewed our experience to see how often such examinations yielded positive results. Records from 11 September 1989 to 13 September 1993 were reviewed. All women referred for detailed fetal sonography for the sole indication of exposure to drugs, toxins, or infectious agents and with a sonographic age of 16-24 menstrual weeks were included. All exposures were included in the study, even those without known teratogenic potential. Patients previously diagnosed with a morphological abnormality or with an abnormal level of maternal serum alpha-fetoprotein were excluded.A total of 125 women with 126 singleton pregnancies comprised the study population. Ten women had multiple exposures. Including the multiple exposures, there was a total of 138 exposures, 104 to drugs and other toxins (45 of which were not known human teratogens), and 34 to infections. The only significant morphological abnormality found was a duplicated kidney in a woman with parvovirus exposure. While parvovirus is a cause of anemia and hydrops, it is not a known human teratogen. We therefore assume that this was a coincidental association. We conclude that teratogen exposure is a low-yield indication for detailed fetal sonography.

In vivo studies of the location of the normal conus medullaris in infancy and childhood have been extended to the fetus utilizing sonography. This prospective study of 33 fetuses showed that the fetal conus medullaris can be visualized in the prone fetus as early as 19 menstrual weeks. By the time the conus medullaris was observed sonographically, its location was within the normal adult range, thus refuting the commonly held notion that the conus medullaris ascends to adult levels sometime in childhood. Our results suggest that a fetal spinal cord termination level of L2-L3 or higher should be considered within normal limits. A termination level of L3 is indeterminate and requires neonatal evaluation. A termination level of L3-L4 or lower is abnormal and should instigate a careful sonographic search for associated abnormalities.

To investigate the relationship of ventriculomegaly (VM) with gestational age (GA) and the severity of the associated Chiari II malformation.The sonograms of 51 fetuses with myelomeningoceles were retrospectively reviewed. VM was judged to be present when the transverse ventricular atrial diameter was greater than 10 mm. The severity of the posterior fossa (PF) deformity was subjectively graded as mild, moderate, or severe. Thirty-four fetuses were scanned ator = 24 weeks GA, and 17 were scanned at24 weeks GA.The prevalence of VM was 61%. However, only 44% of fetusesor = 24 weeks GA had VM, whereas 94% of fetuses24 weeks GA had VM. When compared with fetuses with mild PF deformities, fetuses with moderate or severe deformities had a higher prevalence of VM and the largest ventricles.The prevalence of VM in fetuses with myelomeningoceles varies with both GA and the severity of the associated PF deformity. These observations may provide additional prognostic information once a myelomeningocele is detected at sonography.

Amniocentesis has been advocated by some authors when fetal choroid plexus cysts are discovered, because of their reported association with karyotype abnormalities. We have noted an oval hypoechoic structure projecting into the adjacent choroid plexus, which simulates a cyst when imaged across its short axis, in 39 of 50 consecutive fetuses. This presumably normal structure or pseudocyst may represent the corpus striatum. Knowledge of its existence and benign nature will help avoid diagnostic errors and unnecessary amniocenteses.

The prenatal sonograms of 15 fetuses with cephaloceles (13 occipital, one ethmoidal, and one frontoparietal) were retrospectively reviewed. The prognosis for fetuses with cephaloceles was poor: Only three of 14 with follow-up were born alive (21%), and all are likely to be handicapped. Karyotypes were abnormal in four of nine fetuses tested (44%). Associated cranial abnormalities observed in various numbers of fetuses included ventriculomegaly, the "lemon" sign, a flat basioccipital, "beaked" tectum, and bone defect. A wide variety of neural and nonneural anomalies were associated with cephaloceles. At least one sonographically observed concomitant neural or nonneural axis abnormality or an abnormal karyotype was present in nine of 15 fetuses (60%). Some associated neural malformations noted pathologically were not observed prenatally. Cranial meningoceles were not accurately distinguished from encephaloceles sonographically, and they also were associated with a poor prognosis. Comparison of findings in fetuses with cephaloceles with those of 15 fetuses with cystic hygromas revealed that the two abnormalities can usually be distinguished by the relationship of the mass with the neck and by other cranial findings present in fetuses with cephaloceles but absent in association with cystic hygromas.

A few fetal diseases may benefit from surgical treatment before birth, but hysterotomy and subsequent delivery by cesarean section pose a risk to the otherwise unaffected mother. To assess maternal risk of mortality, morbidity, and reproductive potential after fetal surgery, we reviewed our experience with 17 highly selected women who underwent fetal surgery. Fifteen of these procedures were performed for one of two congenital anomalies: severe bilateral hydronephrosis and congenital diaphragmatic hernia. There were no deaths or serious maternal injuries. In the 14 women who continued pregnancy after hysterotomy, uterine irritability and preterm labor were frequent complications, requiring early confinement in most cases. There has been no detectable effect on future fertility, as indicated by eight subsequent normal pregnancies. We conclude that hysterotomy for fetal surgery can be accomplished without unduly endangering the mother's life or her future reproductive potential. However, morbidity related to premature labor remains a serious problem, and our ability to control uterine contractions after hysterotomy remains the limiting factor in human fetal surgery.The authors describe their experience with 17 highly selected women who underwent hysterotomy for fetal surgery for complex anomalies and then cesarean delivery through the Fetal Treatment Program at the University of California, San Francisco. Maternal risk of mortality, morbidity, and reproductive potential after fetal surgery were assessed. There were no deaths or serious maternal injuries, although the 14 women who continued their pregnancies experienced uterine irritability and preterm labor followed by premature delivery. Seven of the 17 women had eight subsequent normal pregnancies. The authors conclude from their experience that hysterotomy for fetal surgery can be performed without endangering a woman's life or her future fertility. Uterine irritability and premature labor remain serious problems. The authors believe that now is the time to rigorously examine the efficacy, safety, and cost-effectiveness of fetal therapies before they become accepted treatment.

MOST infants with congenital diaphragmatic hernia die because their lungs are inadequate to support extrauterine life. This remains true despite advances in postnatal care, including preoperative stabilization,1 , 2 pharmacologic treatment of persistent pulmonary hypertension of the newborn,3 , 4 and temporary support with extracorporeal membrane oxygenation.5 , 6 Recently, prenatal diagnosis has allowed us to define the natural history of fetal diaphragmatic hernia better: approximately 75 percent of fetuses with congenital diaphragmatic hernia detected before birth die despite optimal postnatal care.7 8 9 10 11 The neonatal outcome is related to the degree of pulmonary hypoplasia from in utero lung compression, which is determined by the timing and volume . . .

We sought to evaluate whether results of Doppler ultrasound alone or in combination with morphologic sonographic evaluation could predict acute renal transplant rejection accurately enough to avoid biopsy. Seventy-one patients were evaluated at time of biopsy. A resistive index greater than 0.90 was 100% predictive of acute rejection, but sensitivity was only 26%. Resistive indices in acute and chronic rejection were often similar. When all morphologic features were abnormal (11%), acute rejection was uniformly present. Regression analysis selected resistive index over morphologic features for ability to predict acute rejection. When resistive index is greater than 0.90 or all morphologic features are abnormal, acute rejection can be predicted with high accuracy, but biopsy remains necessary in many cases.

Magnetic resonance imaging (MRI) was used to evaluate abdominal aortic aneurysms in 27 patients. The findings were compared retrospectively with CT, ultrasound (US), and angiography in 17 cases and prospectively with US in 10 cases. MRI identified the renal arteries in all cases, demonstrated involvement at or above the origin of the renal arteries in eight patients, and showed extension of the aneurysm into the iliac arteries in 12 cases. The outer dimension of the aneurysm, the diameter of the residual lumen, and the length of the aneurysm were measured easily from the MR images. The measurements of transverse dimension of the abdominal aortic aneurysm were similar for MRI, CT, and US. MRI more accurately defined extension above the renal arteries and below the aortic bifurcation. It is concluded that MRI provides the necessary information for the surveillance and preoperative evaluation of abdominal aortic aneurysms.

Neural tube defects (NTDs) are among the most common congenital anomalies in the United States, with an estimated prevalence of 16 per 10,000 births. The measurement of amniotic fluid alpha-fetoprotein (AF-AFP) concentration has been used to detect NTDs since the early 1970s. When the AF-AFP concentration is elevated, ultrasonography is commonly used to confirm the presence of a NTD. In this study, patient charts, amniocentesis records, and ultrasound reports from a three-year period were reviewed. The 97 fetuses identified as being at high risk for NTDs were divided into four groups: those with high AF-AFP concentrations (Groups 1 and 2, with from 3 to 5 standard deviations (SD) above the mean and with more than 5 SD above the mean, respectively): those referred from other institutions because of suspicious sonographic results (Group 3); and those at risk because of a previous sibling with a NTD (Group 4). Ultrasonography was 100 per cent sensitive and 100 per cent specific in diagnosing NTDs. Thus, in pregnancies with an elevated AF-AFP concentration, ultrasonography can reliably identify normal fetuses as well as differentiate between those with NTDs and those with other congenital anomalies. Also, since AF-AFP concentrations decline after 20 weeks' gestation, ultrasonography may be a better test than a repeat amniocentesis in equivocal cases of AF-AFP elevation.

Seven infants born at our institution between July 1979 and June 1982 had congenital diaphragmatic hernia (CDH). Four cases of CDH were correctly identified by fetal ultrasonography. Diagnosis relied upon the demonstration of abdominal organs within the thorax. During this period, no false positive diagnoses of CDH were made. Significant associated sonographic features included polyhydramnios, mediastinal displacement, and distorted upper abdominal anatomy.

To document the characteristic sonographic abnormalities of anencephaly and to identify potentially confusing sonographic features, we reviewed 20 cases of anencephaly. All of these cases were diagnosed prenatally with sonography after 14 menstrual weeks in patients who were seen at our institution between 1984 and 1988. In all cases, the correct diagnosis was made on the prenatal sonograms and was confirmed pathologically. The sonographic diagnosis was primarily based on the absence of brain and calvarium superior to the orbits on coronal views of the fetal head. This typical appearance was altered by the presence of echogenic tissue superior to the orbits in nine (45%) of 20 cases. Pathologically, the tissue corresponded to angiomatous stroma (area cerebrovasculosa) and appeared quite sizable on sonograms in four fetuses (20%). It may appear solid or mixed solid and cystic. In one fetus, it appeared brainlike. Despite this appearance, the sonologist should not be dissuaded from the diagnosis of classic anencephaly. Hydramnios occurred in seven (35%) of 20 patients, and oligohydramnios occurred in none of the patients. Anencephaly may be distinguished from the cranial defects associated with the amniotic band syndrome (amputation defects that occur as the sequelae of amniotic disruption) on the basis of the symmetry of the cranial defects (100% of anencephalic fetuses in this series) and the absence of limb, body wall, and spinal abnormalities that typically accompany the amniotic band syndrome. Although there may be minor variations in the sonographic appearance of the cranial defect of anencephalic fetuses (i.e., much or little angiomatous stroma), we conclude that this anomaly can be accurately detected and diagnosed on fetal sonograms obtained after 14 weeks menstrual age and distinguished from the amniotic band syndrome.

While it is often easy to detect masses in the right upper quadrant that originate from the liver, adrenal gland, or kidney, it may be difficult to determine the anatomic origin of large masses in the posterior aspect of the right upper quadrant. In this paper it is reported that the reflection produced by right upper quadrant retroperitoneal fat is displaced in a characteristic manner by masses originating in this area. This greatly assists in the localization of these masses. Hepatic and subhepatic masses posteriorly displace this echo, while renal and adrenal lesions anteriorly displace it.

Real-time ultrasonography (US) was performed on the allografts of 100 consecutive renal transplant recipients at the time of allograft biopsy. Evaluation of the sonograms included the grading of parameters previously demonstrated to be indicative of allograft rejection. The appearance of the renal sinus fat, allograft size, corticomedullary ratio, sharpness of the corticomedullary junction, medullary conspicuity, presence of focal parenchymal abnormalities, and thickening of the pelvic or infundibular wall were individually evaluated. The authors correlated the US and the histopathologic findings. While the accuracy of a positive prediction of rejection was relatively high (83%-90%), this result is influenced by the relatively high prevalence of rejection in the biopsy group (83%). Accuracy of a negative prediction was uniformly low (17%-30%). Mild rejection was difficult to differentiate ultrasonographically from no rejection, although severe rejection could usually be differentiated from mild or no rejection, particularly in patients with the interstitial type of rejection.

Normal pancreatic ultrasound studies of 28 patients were evaluated as to pancreatic echogenicity and correlated with the morphologic appearance of the pancreas on CT to test the hypothesis that increasing pancreatic echogenicity is related to greater fat infiltration. Statistical analysis indicates that fat is a major but not the only determining factor of increasing echogenicity.

Ultrasound is the modality of choice for the diagnosis of cholelithiasis and for the evaluation of the intra- and extrahepatic biliary tree in the patient with jaundice, but its role in the diagnosis of choledocholithiasis is less certain. We prospectively examined 90 patients who were to undergo endoscopic retrograde cholangiopancreatography (ERCP) by performing right upper quadrant sonography immediately prior to ERCP. We assessed the size of the intra- and extrahepatic ducts and the presence or absence of calculi. ERCP, which was successfully performed in 77 of 94 attempted examinations, percutaneous transhepatic cholangiography, or surgical follow-up composed the diagnostic standard for comparison. Ultrasound was not accurate in the diagnosis (sensitivity, 25%) or exclusion (value of a negative study, 73%) of choledocholithiasis. Furthermore, in the postcholecystectomy patient population, ultrasound assessment of biliary duct size is not a useful predictor of biliary disease. For symptomatic postcholecystectomy patients, we recommend ERCP as the initial diagnostic modality.

To show that the position of the choroid plexus is dependent on gravity and to prove that this fact can be used as a simple means of avoiding the erroneous diagnosis of ventriculomegaly on fetal sonography, we evaluated 75 fetal sonograms retrospectively. Twenty-five fetuses had ventriculomegaly, and 50 had normal cerebral ventricles. The gestational ages ranged from 15 to 39 weeks. To show objectively that the position of the choroid plexus within the lateral ventricle was gravity dependent, we measured the choroid angle in each case. The choroid angle (the angle between the long axis of the choroid plexus and the linear midline echo on transverse axial sonograms through the body of the lateral ventricles) varied directly with ventricular size. In the group with normal-sized ventricles, the values for choroid angle followed a normal, unimodal distribution and had a mean of 14 degrees, a range of 6-22 degrees, and an SD of 4.3 degrees. In cases of ventriculomegaly, the values for choroid angle did not follow a normal distribution and ranged from 29 to 90 degrees. The choroid "dangled" from its attachment at the foramen of Monro and rested on the dependent wall of the lateral ventricle, resulting in a choroid angle that was increased over normal; the degree of the angle was dependent on the severity of the ventricular enlargement. The resting position of the choroid plexus marked the position of the lateral ventricular wall even when the reflection of ultrasound from the ventricular wall itself could not be seen. Detection of the position of the dependent choroid plexus is a simple observation that can be used to avoid the erroneous diagnosis of fetal ventriculomegaly and to help gauge the severity of true ventricular enlargement.

Twenty-five fetuses with ureteropelvic junction obstruction were evaluated to determine the likelihood of progression of hydronephrosis in utero, and the outcome for the neonate. Such information may alter prenatal as well as perinatal management. These observations showed that the degree of dilatation in utero is likely to be greater than that observed postnatally; the degree of dilatation does not necessarily correlate with renal functional impairment measured postnatally; significant progression of dilatation in utero is relatively uncommon, especially in unilateral cases; and uretero-pelvic junction obstruction, even when bilateral, is unlikely to be fatal. Of 21 live newborn infants with follow-up, 14 required surgery and seven were placed under observation.

Antenatal sonography routinely images the fetal cisterna magna. The identification of a prominent cisterna magna on a routine antenatal sonogram performed for obstetric indications may raise the question of a congenital posterior fossa lesion. To delineate the size of the fetal cisterna magna, standardized measurements for the midsagittal depth of the cisterna magna were prospectively obtained on 219 consecutive antenatal sonograms in fetuses of 15 menstrual weeks or more. The cisterna magna depth measured 5 +/- 3 mm; the largest cisterna magna measured 10 mm in depth. In the absence of other findings to suggest a posterior fossa lesion, a prominent cisterna magna is unlikely to be clinically significant.

Seventeen cases of an aberrant sheet of tissue in the amniotic cavity are described to expand and clarify previous observations of this entity. The sheet of tissue demonstrates a thickened base and a free edge that undulates. The fetus moves freely about the sheet of tissue. There are no associated fetal deformities, and infants have no manifestations of the amniotic-band syndrome. Evidence suggests that these sheets may originate from "wrapping" of the amniochorionic membrane over a uterine synechia. These benign sheets of tissue should not be confused with the amniotic-band syndrome.

To assess the possible relationship between the degree of maternal hydration and the sonographic identification of minimal fetal renal pyelectasis, a prospective study was performed in which fetuses demonstrating mild dilation of the renal pelvis (maximum diameter ranging from 3 to 11 mm) were reexamined after the mothers refrained from oral intake for 12 hours. Complete or almost complete resolution of the pyelectasis occurred in only four of 17 kidneys (23.5 per cent) while the remaining fetal kidneys demonstrated little or no change in the degree of pyelectasis following maternal dehydration. This observation, as well as previous experimental research, suggests that the state of maternal oral hydration is not a major cause of minimal fetal pyelectasis. Additionally, the observation of fetal pyelectasis measuring at least 3 mm in greatest dimension is common, occurring in approximately 18 per cent of fetuses older than 24 menstrual weeks.

The distal femoral epiphyseal secondary ossification center (DFE), which can be reliably identified and measured sonographically, may assist the sonologist in predicting third-trimester menstrual age. Between 28 and 35 menstrual weeks, the percentage of fetuses with a DFE progressively increases. Although the mean age at DFE appearance is approximately 32-33 menstrual weeks, the DFE may be seen as early as 29 menstrual weeks. Nevertheless, the age of a fetus without an identifiable DFE is most likely less than or equal to 34 menstrual weeks. Measurements of the DFE show that its size increases linearly: the menstrual age of a fetus whose DFE measures greater than or equal to 7mm is most likely greater than or equal to 37 weeks.

The cisterna magna is effaced in association with myelomeningocele. The authors retrospectively investigated the size of the fetal cisterna magna as a predictor of fetal myelomeningocele in 67 pregnant women (17-38 menstrual weeks) referred for prenatal sonography because of an elevated serum alpha-fetoprotein level (n = 61) or a suspicion of fetal ventriculomegaly on previously obtained sonograms (n = 6). Twenty fetuses had myelomeningocele, 14 had isolated ventriculomegaly, and 33 were normal. A normal-sized cisterna magna (range, 4-9 mm in depth) was present in all normal fetuses. In 19 of 20 fetuses with myelomeningocele, the views of the posterior fossa were adequate, and in each of these the cisterna magna was effaced (n = 18) or very small (n = 1). The cisterna magna was effaced in five of 13 (38%) fetuses with isolated ventriculomegaly in whom the posterior fossa was adequately imaged. Although effacement of the cisterna magna is a nonspecific finding, the high negative predictive value of this si...

Eleven patients whose pregnancies were at 34-36 weeks of gestational development underwent magnetic resonance (MR) imaging. Images of the maternal pelvis were assessed for anatomical changes of pregnancy in comparison with MR images of five non-pregnant volunteers. The relationship of the fetal presenting part to the internal os of the cervix was seen in all patients. Effacement of the cervix was identified when present. The maternal spine demonstrated disk abnormalities in nine patients. Changes in venous flow patterns were readily identified in all patients. The inferior vena cava was flattened or obliterated, a high signal was present in the iliac vessels (TE 56), and large collateral vessels were present.

The nuclear magnetic resonance (NMR) imaging characteristics of gallstones of various composition from 36 patients were studied in vitro using a spin-echo imaging technique. The majority of gallstones (83%) produced no measurable NMR signal despite having a mean water content of 12% and a mean cholesterol content of 61%. Six (17%) of the stones had a weak but measurable signal in the center of the stone, which was thought to represent signal from water in clefts or pores within the stones. The mean water and cholesterol content of the stones with measurable signal did not differ significantly from that of stones with no signal. A possible explanation for these findings, based on the known NMR characteristics of solid materials, is offered.