MRI investigation of normal fetal lung maturation using signal intensities on different imaging sequences.

To purpose of this paper is to study the relation between normal lung maturation signal and changes in intensity ratios (SIR) and to determine which magnetic resonance imaging sequence provides the strongest correlation of normal lung SIs with gestational age. 126 normal singleton pregnancies (20-37 weeks) were examined with a 1.5 Tesla unit. Mean SIs for lungs, liver, and gastric fluid were assessed on six different sequences, and SIRs of lung/liver (LLSIR) and lung/gastric fluid (LGSIR) were correlated with gestational age for each sequence. To evaluate the feasibility of SIRs in the prediction of the state of the lung maturity, accuracy of the predicted SIRs (D*) was measured by calculating relative residuals (D*-D)/D for each sequence. LLSIRs showed significant changes in every sequence (p<0.05), while LGSIRs only on two sequences. Significant differences were shown for the mean of absolute residuals for both LLSIRs (p<0.001) and for LGSIRs (p=0.003). Relative residuals of LLSIRs were significantly smaller on T1-weighted sequence, whereas they were significantly higher for LGSIRs on FLAIR sequence. Fetal liver seems to be adequate reference for the investigation of lung maturation. T1-weighted sequence was the most accurate for the measurement of the lung SIs; thus, we propose to determine LLSIR on T1-weighted sequence when evaluating lung development.

A new look at the fetus: thick-slab T2-weighted sequences in fetal MRI.

Although magnetic resonance imaging (MRI) of the fetus is considered an established adjunct to fetal ultrasound, stacks of images alone cannot provide an overall impression of the fetus. The present study evaluates the use of thick-slab T2-weighted MR images to obtain a three-dimensional impression of the fetus using MRI. A thick-slab T2-weighted sequence was added to the routine protocol in 100 fetal MRIs obtained for various indications (19th to 37th gestational weeks) on a 1.5 T magnet using a five-element phased-array surface coil. Slice thickness adapted to fetal size and uterine geometry varied between 25 and 50mm, as did the field of view (250-350 mm). Acquisition of one image took less than 1s. The pictorial essay shows that these images visualize fetal anatomy in a more comprehensive way than is possible with a series of 3-4mm thick slices. These thick-slab images facilitate the assessment of the whole fetus, fetal proportions, surface structures, and extremities. Fetal pathology may be captured in one image. Thick-slab T2-weighted images provide additional information that cannot be gathered from a series of images and are considered a valuable adjunct to conventional 2D MR images.

Magnetic resonance imaging of the normal placenta.

The goal of this study was to provide a representative description of the normal placenta with contrast medium-free magnetic resonance imaging (MRI) in order to determine a standard of reference. One hundred consecutive singleton pregnancies were investigated by MRI without application of a contrast medium. The mean gestational age (GA) at the time of investigation was 29.5 weeks (range 19-40). Patients with suspected utero-placental insufficiency (UPI) or placental anomalies were excluded. Signal intensities were assessed and correlated with the respective GA. Antenatal MRI without contrast medium was able to depict placental status and morphological changes during gestation. A regular homogeneous structure was found in weeks 19-23. Subsequently, sporadic, slightly marked lobules appeared, which increased in number and markedness with ongoing gestation. Stratification of the lobules was observed after 36 weeks. The ratio of placental and amniotic fluid signal intensities decreased significantly with higher GA and with placental grading. MRI is well suited as an imaging method for the placenta. Our data may be used as a reference in the assessment of the placenta on MRI, and may have further clinical impact with respect to the determination of UPI.

Association of deletions of the chromosomal region 15q24-ter and diaphragmatic hernia: a new case and discussion of the literature.

OBJECTIVE: To provide new insights into how chromosomal aberrations affect fetal development, as well as for the counseling of parents in comparable situations, it is important to characterize and report the genotypes of fetuses with clinical anomalies. METHODS: Molecular cytogenetic analyses in a fetus with congenital diaphragmatic hernia (CDH). RESULTS: This report describes the first case of a deletion of the region q26.1-ter on chromosome 15 occurring as a de novo event associated with CDH. A detailed review of the literature provides further evidence of a functional association between deletions within the chromosomal region 15q24-ter and the development of CDH. CONCLUSIONS: The obtained data argue that detection of such a deletion in the region 15q24-ter associated with CDH likely predicts a poor prognosis. This report highlights the importance of giving special diagnostic attention to the chromosomal region 15q24-ter when prenatal ultrasound examination provides evidence of a CDH and warrants further research to identify genetic elements within the chromosomal region 15q24-ter related to the development of diaphragmatic hernia.

Single-dose pharmacokinetics of ofloxacin during continuous venovenous hemofiltration in critical care patients.

BACKGROUND: Ofloxacin is a quinolone administered to patients with severe infections. Pharmacokinetic data on ofloxacin in critically ill patients on renal replacement therapy are sparse and conflicting. METHODS: Eight patients with anuric acute renal failure were administered 400 mg of ofloxacin intravenously. The pharmacokinetics of ofloxacin was analyzed during continuous venovenous hemofiltration (CVVH) with a high-flux polysulfone membrane. Serum and ultrafiltrate levels of ofloxacin were measured by means of high-performance liquid chromatography. RESULTS: Mean serum ofloxacin concentration peak was 5.5 +/- 0.7 mg/L. Elimination half-life, hemofiltration clearance, and total removal were 2.8 +/- 0.5 hours, 89.9 +/- 4.5 mL/min, and 76.9% +/- 7.1%, respectively. CONCLUSION: Ofloxacin is significantly and rapidly eliminated by CVVH with a high-flux polysulfone membrane.