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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.

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.

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.

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.

The CT scan of 100 patients with ascites were reviewed to assess the relative distribution of fluid in the greater and lesser peritoneal sacs. Discordant fluid accumulations were found in most cases. Patients with benign, transudative ascites (e.g., peritoneal dialysis, cirrhosis, congestive heart failure) had large greater sac collections with little fluid in the lesser sac. Those patients with diseases of organs bordering the lesser sac (e.g., pancreatitis, posteriorly penetrating gastric ulcer) had larger lesser sac fluid collections with little in the greater sac. Cytologically positive carcinomatosis of the abdomen was associated with concordant fluid volumes in these two spaces. These findings suggest that fluid within the lesser sac is not a typical manifestation of generalized peritoneal ascites and that its presence should direct a search for pathology in neighboring organs and for peritoneal malignancy.

Several cryosurgical techniques for freezing hepatic parenchyma have been developed. To assess the efficacy of sonographic monitoring of hepatic cryosurgery, an experimental animal model was devised. Real-time sonography was used to monitor the in vivo evolution of hypothermically induced hepatic cryolesions in four mongrel dogs. The results suggest that sonography is an effective and accurate means of monitoring the entire freezing and thawing cycle in hepatic cryosurgery.

Prenatal diagnosis of genetic defects was done using fetal blood sampling in 167 at-risk pregnancies, by fetal skin biopsy in 15 pregnancies, and by fetal liver biopsy in 8 pregnancies. Fetal blood sampling was done by fetoscopy through January 1985 and by sonographically directed percutaneous umbilical blood sampling since then. In our series, cytogenetics has become the major indication for fetal blood sampling, increasing from 6% of the cases with fetoscopy to 48% with umbilical blood sampling. Fetoscopy provided pure fetal blood in 61% of cases while umbilical blood sampling provided pure fetal blood 97% of the time. The corrected risk of fetal demise after percutaneous umbilical fetal blood sampling was 2% and after fetoscopy was 4%.

Recent advances in techniques for fetal catheterization and surgical manipulation have made intrauterine therapy of certain anomalies a reality [1 -4]. With a variety of treatment options now available, the fetus must be afforded as cornprehensive a diagnostic evaluation as possible. It may be insufficient to identify an abnormality and await delivery to perform a more complete diagnostic workup. Precise and detailed anatomic information is necessary to select appropriate cases for prenatal therapy and to plan the most efficacious therapeutic approach. We recently encountered a fetus with urinary tract obstruction in whom combined radiologic and sonographic imaging was necessary to establish the level of obstruction.

Roentgen findings in 107 girls under the age of ten years who had proven recurrent urinary tract infections were analyzed. From the excretory urograms done on these children, renal and pelvocalyceal outlines were accurately traced. Subsequently, renal length and parenchymal thickness at multiple points were measured. The presence or absence and grade of reflux were determined by voiding cystourethrography. Finally, the clinical history was correlated with the roentgen findings. With three exceptions, scarring and clubbing in the presence of infection occurred only in refluxing renal units. Kidneys exposed to a higher grade of reflux more frequently showed scarring and clubbing (p0.001). Seventeen out of 40 renal units either developed or had increase in clubbing and scarring while the patients were being followed. After surgical correction of reflux, 16 of 24 previously clubbed and scarred kidneys showed progression of the lesions, usually within 24 months after operation. All children whose kidneys showed progression after surgical operation had experienced an episode of acute urinary infection with chills and fever before operation. No significant difference existed in the age at clinical onset of infection in patients with ureteral reflux with or without roentgen evidence of clubbing and scarring. This study documents the close relationship between clubbing and scarring and reflux in the presence of urinary infection in infants and children.

Of 134 girls with demonstrable ureterovesical reflux, 61 (105 ureters) had the reflux surgically corrected with an overall surgical cure rate of 97 percent. In the remaining 73 children (112 ureters), the reflux was treated conservatively with medical management alone. During the follow-up period no significant differences were demonstrated in the overall incidence of urinary tract infection; two years following corrective operation or medical treatment more than 50 percent of both medically and surgically treated children were still experiencing infections. A pronounced decrease, however, occurred in the incidence of clinical pyelonephritis among the surgically treated group. Following correction of reflux, the incidence of pyelonephritis was similar in both medically and surgically treated cases and was approximately the same as that found in a comparable group of children without reflux. In approximately two-thirds of refluxing renal units in which there was evidence of clubbing and scarring before medical or surgical therapy, deterioration progressed during the follow-up period. In most of these cases infection control was felt to be inadequate with episodes of clinical pyelonephritis occurring during the period of medical management, or, in the surgically treated group, occurring just before corrective operation and the scar appearing within two years after operation. The majority of renal units in which calyceal clubbing and parenchymal scarring was present had the most severe grades of reflux.