MRI-based ratio of fetal lung volume to fetal body volume as a new prognostic marker in congenital diaphragmatic hernia.

OBJECTIVE: The objective of our study was to evaluate the prognostic accuracy of the MRI-based ratio of fetal lung volume (FLV) to fetal body volume (FBV) for predicting survival and the need for extracorporeal membrane oxygenation (ECMO) therapy in fetuses with congenital diaphragmatic hernia (CDH). MATERIALS AND METHODS: MRI was performed in 96 fetuses (34 females and 62 males; mean gestational age, 33 ± 5 [SD] weeks; range, 23-39 weeks) with CDH and 44 healthy control subjects. FLV and FBV were measured for each fetus by one of three investigators, and we calculated the FLV/FBV ratio. Additionally, a subgroup analysis of growth-restricted fetuses was performed. Logistic regression analysis was used to model the dependence of survival and ECMO requirement on the FLV/FBV ratio. Prognostic accuracy was evaluated by applying the area under the curve (AUC). RESULTS: Seventy-eight of the 96 (81%) fetuses survived and 35 (36%) neonates needed ECMO therapy. The FLV/FBV ratio was significantly higher in fetuses who survived (p < 0.0001; AUC = 0.829). Neonates who received ECMO therapy showed a significantly lower prenatal FLV/FBV ratio (p = 0.0001; AUC = 0.811) than neonates who did not need ECMO therapy. A subgroup analysis (n = 13) showed a trend toward a higher FLV/FBV ratio of survivors in comparison with nonsurvivors (p = 0.065; AUC = 0.875). CONCLUSION: In our study, the MRI-based FLV/FBV ratio was able to predict neonatal survival and ECMO requirement in children with CDH with high accuracy. Unlike other prognostic parameters, FLV/FBV ratio is independent of a reference to a control group and may enhance prognostic accuracy particularly in growth-restricted neonatal patients.

Repetitive MR measurements of lung volume in fetuses with congenital diaphragmatic hernia: individual development of pulmonary hypoplasia during pregnancy and calculation of weekly lung growth rates.

OBJECTIVE: To investigate individual changes in fetal lung volume (FLV) in fetuses with isolated congenital diaphragmatic hernia (CDH) and to calculate weekly growth rates of the FLV using serial MR examinations during pregnancy. METHODS: MR-FLV was measured in 89 fetuses with CDH. All fetuses received two MRIs. A mean weekly growth rate of the FLV was determined for each fetus and compared with the growth rate of healthy fetuses. RESULTS: Mean observed-to-expected MR-FLV (o/e MR-FLV) measured at the first MRI was 33.3 ± 12.2% and 29.5 ± 10.9% at the second MRI. In 61% of all fetuses (54/89) the o/e MR-FLV decreased during pregnancy, 26% (23/89) showed an increase in the o/e MR-FLV and 13 % (12/89) had stable values. First and last o/e MR-FLV values were significantly associated with mortality and neonatal extracorporeal membrane oxygenation (ECMO) requirement with a higher prognostic accuracy of MR-FLV measurements near delivery. Patients with CDH had lower weekly lung growth rates than healthy fetuses. There was a significant difference in the mean weekly growth rate between survivors and non-survivors and patients with and without ECMO requirement. CONCLUSION: Individual development of FLV in patients with CDH during pregnancy is extremely variable. Follow-up MR-FLV measurements are advisable before deciding upon pre- and postnatal therapeutic options. KEY POINTS: • Lung development in congenital diaphragmatic hernia (CDH) during pregnancy is extremely variable. • MRI demonstrates that lung growth rate is reduced in fetuses with CDH. • The final observed-to-expected fetal lung volume provides the best prognostic information. • Follow-up measurements are advisable before deciding upon therapeutic options.

Periodic MRI lung volume assessment in fetuses with congenital diaphragmatic hernia: prediction of survival, need for ECMO, and development of chronic lung disease.

OBJECTIVE: The purpose of the study was to investigate the ability to predict survival, need for extracorporeal membrane oxygenation (ECMO), and incidence of chronic lung disease in patients with congenital diaphragmatic hernia in the context of a classification into three different times of gestation (< 28, 28-32, and > 32 weeks) by assessing the ratio between observed and expected MRI fetal lung volume. MATERIALS AND METHODS: The data analysis included 226 fetuses with congenital diaphragmatic hernia. MRI was performed at different times of gestation with a T2-weighted HASTE sequence. Receiver operating characteristic curve analysis was performed to investigate the prognostic value of assessment of the ratio between observed and expected MRI fetal lung volumes at different stages of fetal growth. RESULTS: For all reviewed times of gestation, the ratio between observed and expected MRI fetal lung volumes had almost equivalent statistically significant differences for neonatal survival (p ≤ 0.0029), need for ECMO therapy (p ≤ 0.0195), and development of chronic lung disease (p ≤ 0.0064). Results with high prognostic accuracy for early and for medium and late times in gestation also were obtained. Receiver operating characteristic analysis showed the highest area under the curve (≥ 0.819) for neonatal survival. CONCLUSION: In patients with congenital diaphragmatic hernia, the relation between observed and expected MRI fetal lung volume is a valuable prognostic parameter for predicting neonatal mortality, morbidity represented by the development of chronic lung disease, and the need for ECMO therapy in early gestation (< 28 weeks) as well as later gestation with no statistically significant differences.

Fetal lung volume in congenital diaphragmatic hernia: association of prenatal MR imaging findings with postnatal chronic lung disease.

PURPOSE: To assess whether chronic lung disease (CLD) in surviving infants with congenital diaphragmatic hernia (CDH) is associated with lung hypoplasia on the basis of the results of antenatal observed-to-expected fetal lung volume (FLV) ratio measurement at magnetic resonance (MR) imaging. MATERIALS AND METHODS: The study received approval from the institutional review board, with waiver of informed consent for this retrospective review from patients who had previously given informed consent for prospective studies. The ratio of observed to expected FLV at MR imaging was calculated in 172 fetuses with CDH. At postpartum day 28, the need for supplemental oxygen implicated the diagnosis of CLD. At day 56, patients with CLD were assigned to one of three groups-those with mild, moderate, or severe CLD-according to their demand for oxygen. Logistic regression analysis was used to assess the prognostic value of the individual observed-to-expected FLV ratio for association with postnatal development of CLD. RESULTS: Children with CLD were found to have significantly smaller observed-to-expected FLV ratios at MR imaging than infants without CLD (P < .001). Grading of CLD revealed significant differences in observed-to-expected FLV ratio between patients with mild CLD and those with moderate (P = .012) or severe (P = .007) CLD. For an observed-to-expected FLV ratio of 5%, 99% of patients with CDH developed CLD, compared with less than 5% of fetuses with an observed-to-expected FLV ratio of 50%. Perinatally, development and grade of CLD were further influenced by the need for extracorporeal membrane oxygenation (ECMO) (P < .001) and gestational age at delivery (P = .009). CONCLUSION: Manifestation of CLD in surviving infants with CDH is associated with the prenatally determined observed-to-expected FLV ratio. Early neonatal therapeutic decisions can additionally be based on this ratio. Perinatally, ECMO requirement and gestational age at delivery are useful in further improving the estimated probability of CLD.

Ultra late onset group B streptococcal sepsis with acute renal failure in a child with urethral obstruction: a case report.

INTRODUCTION: Group B streptococci are a well-known cause of early and late onset sepsis. In neonates and older children gram-negative bacteria are mostly found in urinary tract infections and urosepsis. In adults predisposing factors for group B streptococci urinary tract infection may include diabetes mellitus and chronic renal failure. CASE PRESENTATION: We present a rare case of a five-month-old Caucasian boy with ultra late onset urosepsis and acute renal failure caused by group B streptococci serotype V. Excretion urography showed a subvesical obstruction that consequently was surgically corrected after antibiotic treatment of the acute infection. CONCLUSIONS: Group B streptococci serotype V, urogenitary tract malformations, previous hospitalization and medical interventions may be important risk factors for the development of ultra late onset Group B streptococci sepsis in non-neonates.

In vitro models of the fetal lung: comparison of lung volume measurements with 3-dimensional sonography and magnetic resonance imaging.

OBJECTIVES: Three-dimensional (3D) sonography is an established volumetric method in gynecology and obstetrics. The aim of this study was to investigate the variability of 3D sonographic measurements and their accuracy in comparison with magnetic resonance imaging (MRI) for assessing fetal lung volume using in vitro lung models. METHODS: Twenty-three in vitro lung models with randomly defined volumes ranging from 1 to 60 mL were made from gelatin with plastic sheaths, manually molded into the shape of fetal lungs. The models were measured using 3D sonography and MRI. The 3D sonographic volumes were calculated using the rotational technique with angles of 6° and 30°. Multiplanar T2-weighted sequences were used for the MRI measurements. The percentage error and absolute percentage error were calculated for each method, and intraobserver and interobserver variability in 3D sonographic measurements was assessed with intraclass correlation coefficients (ICCs). Agreement between calculated and real volumes using the limits of agreement method was also evaluated. RESULTS: The ICCs for the rotation angles indicated very good intraobserver and interobserver variability (6°, 0.995 and 0.996; 30°, 0.997 and 0.985). No systematic errors were observed in the mean percentage errors for 3D sonographic measurements or MRI volumetry. The lowest median absolute percentage error (1.76) was obtained with MRI volumetry, significantly lower than the values for sonography (6°, 5.00; P < .001; 30°, 5.49; P < .001). There were no significant differences in absolute percentage errors between the rotation angles (P = .82) and no significant differences in limits of agreement between 3D sonography and MRI (6°, P = .76; 30°, P = .39). CONCLUSIONS: Three-dimensional sonographic volumetry was almost as accurate as MRI in this in vitro model and can be regarded as a good alternative method. Further research is needed to confirm these findings in vivo and to assess the prognostic value in fetuses with lung hypoplasia (eg, congenital diaphragmatic hernias).

Reliability and validity of MR image lung volume measurement in fetuses with congenital diaphragmatic hernia and in vitro lung models.

PURPOSE: To prospectively assess the reliability of magnetic resonance (MR) image volume measurement in fetuses with congenital diaphragmatic hernia (CDH) and the reliability and validity of measurements in in vitro lung models. MATERIALS AND METHODS: This study was approved by the ethics committee, and informed consent was obtained. MR fetal lung volume (FLV) was measured in 40 consecutive fetuses with CDH by using half-Fourier acquired single-shot turbo spin-echo MR imaging and true fast imaging with steady-state precession at 24-36 weeks gestation (mean gestational age, 30.6 weeks +/- 3.5 [standard deviation]). Lung volumes were independently assessed in three orthogonal section planes by two experienced observers. Additionally, 28 in vitro lung models of defined volumes of 1-60 mL were evaluated the same way. To assess measurement validity and reliability, the intraclass correlation coefficient (ICC) and the Bland-Altman plot were used. RESULTS: The interobserver reliability was high for both the lung models and FLV measurements (ICC, 0.999 and 0.928, respectively). Measurement validity was also good, with a mean difference between the calculated volume and the true volume of 0.4 mL (95% confidence interval: 0.30, 0.48). Measurement reliability and validity did not depend, to any considerable degree, on imaging plane or sequence (ICC range, 0.878-0.999) or on total volume. CONCLUSION: The reliability and validity of MR volume measurements are high. The method is independent of the sequence and the imaging plane and can be performed with a very good interobserver agreement, even in small volumes.