Reference ranges of fetal spleen biometric parameters and volume assessed by three-dimensional ultrasound and their applicability in spleen malformations

The Fetal Spleen in Low-Risk Pregnancies and prior to Preterm Birth: Observational Study of the Role of Anatomical and Functional Magnetic Resonance Imaging

INTRODUCTION

Spontaneous preterm birth complicates ∼7% of pregnancies and causes morbidity and mortality. Although infection is a common etiology, our understanding of the fetal immune system in vivo is limited. This study aimed to utilize T2-weighted imaging and T2* relaxometry (which is a proxy of tissue oxygenation) of the fetal spleen in uncomplicated pregnancies and in fetuses that were subsequently delivered spontaneously prior to 32 weeks.

METHODS

Women underwent imaging including T2-weighted fetal body images and multi-eco gradient echo single-shot echo planar sequences on a Phillips Achieva 3T system. Previously described postprocessing techniques were applied to obtain T2- and T2*-weighted imaging of the fetal spleen and T2-weighted fetal body volumes.

RESULTS

Among 55 women with uncomplicated pregnancies, an increase in fetal splenic volume, splenic:body volume, and a decrease in splenic T2* signal intensity was demonstrated across gestation. Compared to controls, fetuses who were subsequently delivered prior to 32 weeks' gestation (n = 19) had a larger spleen when controlled for the overall size of the fetus (p = 0.027), but T2* was consistent (p = 0.76).

CONCLUSION

These findings provide evidence of a replicable method of studying the fetal immune system and give novel results on the impact of impending preterm birth on the spleen. While T2* decreases prior to preterm birth in other organs, preservation demonstrated here suggests preferential sparing of the spleen.

Fetal Splenic Artery Pulsatility Index May Predict the Need for Neonatal Intensive Care in Gestational Diabetes Class A1 Cases

The fetal splenic artery pulsatility index is a parameter that reflects fetal well-being and has been used as a predictor of adverse pregnancy outcomes. The aim of this study was to investigate the predictive value of the splenic artery pulsatility index in gestational diabetes mellitus class A1 cases for intensive care unit admission. In this prospective case-controlled study, only sixty single pregnancy cases diagnosed with gestational diabetes mellitus class A1 were evaluated. Fetal splenic artery Doppler parameters such as peak systolic velocity, pulsatility index, resistivity index, and end-diastolic velocity were measured in all cases. The rate of requirements for the neonatal intensive care unit was noted. In cases requiring fetal intensive care, the fetal splenic pulsatility index was found to be statistically significantly lower than in healthy cases without it (0.94 ± 0.29 vs. 1.70 ± 0.53, respectively, p < 0.001, Student's t-test). When the fetal splenic PI cutoff value was selected as 1.105 cm3, the sensitivity was calculated as 97.9% and the specificity as 58.3% for predicting the need for fetal intensive care (AUC 0.968, p < 0.001, 95% CI 0.929-0.998). The use of a low fetal splenic artery PI parameter is a significant and good indicator for predicting the need for fetal intensive care according to the binary logistic regression analysis result (p = 0.006). This study suggests that evaluation of fetal splenic artery Doppler in mothers with gestational diabetes mellitus may be used to predict neonates requiring a newborn intensive care unit. Therefore, it is recommended that obstetricians use this simple, rapid, and valuable evaluation of fetal splenic artery Doppler and alert the neonatologist that a newborn intensive care unit may be required.

Automated body organ segmentation, volumetry and population-averaged atlas for 3D motion-corrected T2-weighted fetal body MRI

Structural fetal body MRI provides true 3D information required for volumetry of fetal organs. However, current clinical and research practice primarily relies on manual slice-wise segmentation of raw T2-weighted stacks, which is time consuming, subject to inter- and intra-observer bias and affected by motion-corruption. Furthermore, there are no existing standard guidelines defining a universal approach to parcellation of fetal organs. This work produces the first parcellation protocol of the fetal body organs for motion-corrected 3D fetal body MRI. It includes 10 organ ROIs relevant to fetal quantitative volumetry studies. We also introduce the first population-averaged T2w MRI atlas of the fetal body. The protocol was used as a basis for training of a neural network for automated organ segmentation. It showed robust performance for different gestational ages. This solution minimises the need for manual editing and significantly reduces time. The general feasibility of the proposed pipeline was also assessed by analysis of organ growth charts created from automated parcellations of 91 normal control 3T MRI datasets that showed expected increase in volumetry during 22-38 weeks gestational age range.

3D T2w fetal body MRI: automated organ volumetry, growth charts and population-averaged atlas

Structural fetal body MRI provides true 3D information required for volumetry of fetal organs. However, current clinical and research practice primarily relies on manual slice-wise segmentation of raw T2-weighted stacks, which is time consuming, subject to inter- and intra-observer bias and affected by motion-corruption. Furthermore, there are no existing standard guidelines defining a universal approach to parcellation of fetal organs. This work produces the first parcellation protocol of the fetal body organs for motion-corrected 3D fetal body MRI. It includes 10 organ ROIs relevant to fetal quantitative volumetry studies. We also introduce the first population-averaged T2w MRI atlas of the fetal body. The protocol was used as a basis for training of a neural network for automated organ segmentation. It showed robust performance for different gestational ages. This solution minimises the need for manual editing and significantly reduces time. The general feasibility of the proposed pipeline was also assessed by analysis of organ growth charts created from automated parcellations of 91 normal control 3T MRI datasets that showed expected increase in volumetry during 22-38 weeks gestational age range. In addition, the results of comparison between 60 normal and 12 fetal growth restriction datasets revealed significant differences in organ volumes.

Three‑Dimensional Ultrasonography in Preoperative and Postoperative Volume Assessment of the Undescended Testicle

BACKGROUND Ultrasound (US) is the preferred imaging method for cryptorchidism, but most guidelines indicate that its value is questionable. The aim of this study was to evaluate the clinical value of ultrasonic mobility and testicular atrophy index (TAI) based on three‑dimensional US (3DUS) in preoperative and postoperative assessment of the undescended testis. MATERIAL AND METHODS Data from 158 children with unilateral extraperitoneal cryptorchidism were collected and their diagnoses were surgically confirmed. They were divided into different age groups and into 2 ultrasonic mobility groups: the mobile group (MG) and the restricted group (RG). Differences in sonographic characteristics between different groups were compared. Three-dimensional ultrasound performed with virtual organ computer-aided analysis (VOCAL) was used to determined preoperative and postoperative TAI and the reliability of TAI was analyzed. RESULTS Measurement of testicular volume with the VOCAL method was significantly more reliable than that done with the two-dimensional Lambert method. In all age groups, preoperative testicular volumes were smaller than that in the contralateral scrotal testis and postoperatively, they increased steadily. Both preoperative and postoperative TAI were higher in the RG than in the MG. In the MG, postoperative TAI decreased significantly in all age groups. In the RG, in contrast, effective volume growth was only achieved in patients who had undergone surgery before they reached age 1 year. CONCLUSIONS TAI values determined with 3DUS using the VOCAL technique objectively reflect recovery of testicular volume following surgery for undescended testicle. Ultrasonic mobility evaluation is beneficial for clinical management of the condition.

Three-dimensional sonographic minute structure analysis of fetal cerebellar vermis development and malformations: utilizing volume contrast imaging

PURPOSE

To obtain three-dimensional ultrasonic (3D US) structural details and biometrics of the fetal cerebellar vermis and evaluate the value of developmental and malformation identification.

METHODS

The 3D US minute structure of the fetal cerebellar vermis in mid-sagittal view was detected in normal fetuses (n = 438; 16-41 weeks). Biometric sizes were measured to establish the stage-specific norms and reproducibility analysis. Additionally, 28 fetuses with suspected abnormal posterior fossa contents were assessed to analyze the clinical value.

RESULTS

The minute structure of normal fetuses, including cerebellar vermis contours and the fastigial recess of the fourth ventricle, were visible around Week 19. The main lobules and fissures were apparent around Week 22, and all nine lobules, fissures, and the fourth ventricle were clearly displayed by Week 28. Cerebellar vermis biometric sizes (anterior-posterior length, cranio-caudal length, circumference, and surface area (SA)) grew in a linear fashion with high reliability, especially SA measurements (for intraclass, ICC 0.989, 95% CI (0.980-0.994); for interclass, ICC 0.992, 95% CI (0.984-0.996)). On the middle sagittal section of 3D US, the SA reduced at least 50% in the Dandy-Walker group with no recognizable cerebellar vermis structures showing. The SA in vermian hypoplasia malformation reduced during [Formula: see text] to 50% with the primary/secondary fissures absent or partly absent and arborization of the lobules reduced. That would be an important diagnosis and antidiastole clue. Combined with minute structural observation, sonographic diagnoses were accurate in 88% of cases.

CONCLUSION

Minute structures obtained by 3D US were clinically useful in the evaluation of cerebellar vermis development and cerebellar vermis malformations.

Organogenesis and foetal haemodynamics during the normal gestation of healthy black-rumped agoutis (Dasyprocta prymnolopha, Wagler, 1831) bred in captivity

The objective of this study was to define the patterns of organogenesis and foetal haemodynamics during the normal gestation of healthy agoutis (Dasyprocta prymnolopha) kept in captivity. Thirty pregnant agoutis that ranged in size from small to medium and weighed between 2.5 and 3 kg underwent B-mode and Doppler ultrasonography for the biometric evaluation of the foetal organs. The foetal aortic blood flow proved to be predominantly systolic, and the measured flow velocity was 78.89 ± 2.95 cm/s, with a maximum pressure gradient of 2.12 ± 0.27 mmHg. The liver was characterized by its large volume, occupying the entire cranial aspect of the abdominal cavity, and it was associated cranially with the diaphragm and caudally with the stomach. The flow velocity in the portal vein was estimated to equal 12.17 ± 2.37 cm/s, with a resistivity index of 0.82 ± 0.05. The gallbladder was centrally located and protruded cranially towards the diaphragm. The spleen was visualized as an elongated structure with tapered cranial and caudal extremities, and the foetal kidneys were visualized bilaterally in the retroperitoneal region, with the right kidney positioned slightly more cranially than the left. The morphological characterization and hemodynamic analysis of the foetal organs of black-rumped agoutis via B-mode and Doppler ultrasonography allow determination of the vascular network and of reference values for the blood flow required for perfusing the anatomical elements essential for maintaining the viability of foetuses at different gestational ages.

[Detailed in utero ultrasound description of 34 cases of congenital cytomegalovirus infection]

OBJECTIVES

To describe precisely prenatal ultrasound features in congenital cytomegalovirus (CMV) infection.

MATERIAL AND METHODS

We retrospectively evaluated the ultrasound descriptions of cases of congenital CMV infection between 2004 and 2013.

RESULTS

In 74 congenital CMV infections, related ultrasound abnormalities were reported in 34 cases (45.9%). Abnormalities reported were either cerebral (11 cases), either extracerebral (6 cases), or associated (17 cases). A total of 22/34 cases presented extracerebral features of 11 different sorts of abnormalities, mainly intra-uterine growth retardation (11 cases) and hyperechogenic bowel (10 cases) and 26/34 cases presented cerebral features of 14 different sorts, mainly brain calcifications (12 cases) and occipital horn cavity (12 cases). MRI was performed in 25 cases and have found additional abnormalities in 8 cases. These abnormalities are not specific to CMV infection. However, a frequent finding attracted our attention: the anechogenic cavity located on the extremity of the occipital horn.

CONCLUSION

A potentially specific sign, inexistent in other fetal pathologies, is an anechogenic cavity located on the extremity of the occipital and/or temporal horn, a germinal region which contains numerous proliferating and differentiating germinal cells. A better understanding of these signs could increase the sensitivity of ultrasound, and clarify the pathophysiology of congenital CMV infection.