Infant craniospinal ultrasonography: beyond hemorrhage and hydrocephalus

Cranial ultrasound in preterm infants ≤ 32 weeks gestation-novel insights from the use of very high-frequency (18-5 MHz) transducers: a case series

The quality of cranial ultrasound has improved over time, with advancing technology leading to higher resolution, faster image processing, digital display, and back-up. However, some brain lesions may remain difficult to characterize: since higher frequencies result in greater spatial resolution, the use of additional transducers may overcome some of these limitations. The very high-frequency transducers (18-5 MHz) are currently employed for small parts and lung ultrasound. Here we report the first case series comparing the very high-frequency probes (18-5 MHz) with standard micro-convex probes (8-5 MHz) for cranial ultrasound in preterm infants. In this case series, we compared cranial ultrasound images obtained with a micro-convex transducer (8-5 MHz) and those obtained with a very high-frequency (18-5 MHz) linear array transducer in 13 preterm infants ≤ 32 weeks gestation (9 with cerebral abnormalities and 4 with normal findings). Ultrasound examinations using the very high-frequency linear transducer and the standard medium-frequency micro-convex transducer were performed simultaneously. We also compared ultrasound findings with brain MRI images obtained at term corrected age. Ultrasound images obtained with the very high-frequency (18-5 MHz) transducer showed high quality and accuracy. Notably, despite their higher frequency and expected limited penetration capacity, brain size is small enough in preterm infants, so that brain structures are close to the transducer, allowing for complete evaluation.    Conclusion: We propose the routine use of very high-frequency linear probes as a complementary scanning modality for cranial ultrasound in preterm infants ≤ 32 weeks gestation. What is Known: • Brain lesions in preterm infants may remain insufficiently defined through conventional cranial ultrasound scan. • Higher frequency probes  offer better spatial resolution but have a narrower filed of exploration and limited penetration capacity. What is New: • Very high-frequency probes were compared with standard medium-frequency probes for cranial ultrasound in infants  ≤ 32 weeks' gestation. • Thanks to the smaller skull size of preterm infants, the new very high-frequency transducers allowed a complete and accurate evaluation.

Subventricular zone stem cell niche injury is associated with intestinal perforation in preterm infants and predicts future motor impairment

Brain injury is highly associated with preterm birth. Complications of prematurity, including spontaneous or necrotizing enterocolitis (NEC)-associated intestinal perforations, are linked to lifelong neurologic impairment, yet the mechanisms are poorly understood. Early diagnosis of preterm brain injuries remains a significant challenge. Here, we identified subventricular zone echogenicity (SVE) on cranial ultrasound in preterm infants following intestinal perforations. The development of SVE was significantly associated with motor impairment at 2 years. SVE was replicated in a neonatal mouse model of intestinal perforation. Examination of the murine echogenic subventricular zone (SVZ) revealed NLRP3-inflammasome assembly in multiciliated FoxJ1+ ependymal cells and a loss of the ependymal border in this postnatal stem cell niche. These data suggest a mechanism of preterm brain injury localized to the SVZ that has not been adequately considered. Ultrasound detection of SVE may serve as an early biomarker for neurodevelopmental impairment after inflammatory disease in preterm infants.

Hydrocephaly Analysis Supported by Computerized Tomography and Nuclear Magnetic Resonance

Hydrocephalus is widely known as "hydrocephaly" or "water in the brain," a building up of abnormal cerebrospinal fluid in the brain ventricles. Due to this abnormality, the size of the head becomes larger and increases the pressure in the skull. This pressure compresses the brain and causes damage to the brain. Identification by imaging techniques on the hydrocephalus is mandatory to treat the disease. Various methods and equipment have been used to image the hydrocephalus. Among them, computerized tomography (CT) scan and nuclear magnetic resonance (NMR) are the most considered methods and gives accurate result of imaging. Apart from imaging, cerebrospinal fluid-based biomarkers are also used to identify the condition of hydrocephalus. This review is discussed on "hydrocephalus" and its imaging captured by CT scan and NMR to support the biomarker analysis.

Evaluation of symmetrical increased echogenicity of bilateral caudothalamic grooves detected on cranial ultrasonography by comparing with susceptibility-weighted imaging

OBJECTIVE

To assess symmetrical increased echogenicity of bilateral caudothalamic grooves (SIEBCG) detected on newborn cranial ultrasonography (CUS) using magnetic resonance susceptibility-weighted imaging (SWI).

MATERIALS AND METHODS

A total of 14 newborns (8 girls; 12 premature with mean gestational age of 30 weeks and 5 days, 2 mature) who were detected to have SIEBCG on routine serial CUS and underwent cranial magnetic resonance imaging (MRI) were recruited for the study. The cranial MRI examinations including SWI acquired on the same day of SIEBCG detection and serial CUS to assess the progress of SIEBCG lesions in the following 6 month period were retrospectively evaluated and compared for the presence of germinal matrix hemorrhage.

RESULTS

On SWI, solely one patient (7, 1%) had signal alteration on caudothalamic groove compatible with grade 1 germinal matrix hemorrhage. Two patients (14, 2%) had parenchymal (on cerebellar and parietal white matter) millimetric hemorrhagic foci. Seven patients (50%) had signs of presumptive hypoxic insult including hyperintense dots on centrum semiovale and periventricular white matter in five, and increased signal intensity on the globus pallidi in two, on T1-weighted images. Four patients (28, 6%) had normal findings. Of these, 10 patients became normal on follow-up CUS at postterm-equivalent age, whereas four were missing.

CONCLUSION

Symmetrical increased echogenicity of bilateral caudothalamic grooves seen on newborn CUS may be the indicator of other pathologies as ischemic insult or focal parenchymal hemorrhage. In the presence of SIEBCG, further examination with SWI should be performed.

Emergency Point-of-Care Ultrasound Identification of Pediatric Ventriculoperitoneal Shunt Malfunctions

Ventriculoperitoneal shunt malfunctions should be accurately and efficiently diagnosed. In this case series, we describe the use of point-of-care ultrasound to rapidly identify pediatric ventriculoperitoneal shunt tubing fracture, obstruction, and infection.

Evaluation of Dorsal Midline Discolorations with Physical Examination and Ultrasound

OBJECTIVE

To assess the association between dorsal midline skin discolorations, tethering of the spinal cord, and the role of ultrasound screening of these stigmata, focusing specifically on vascular lesions.

STUDY DESIGN

We conducted a prospective observational study of infants <6 months of age with suspicious dorsal midline skin stigmata. All were evaluated by physical examination and ultrasound scan. A subset also had a magnetic resonance imaging examination. We examined the association between small, red-shaded discolorations and their respective imaging findings.

RESULTS

Among 100 cases with discolorations of vascular types, either isolated or combined with low-risk simple dimples or deviated gluteal folds, none had clinically significant pathologic findings requiring surgical intervention.

CONCLUSIONS

Midline lumbar discolorations are more benign than previously thought. Despite the very low association of this group of stigmata with surgical implications, we still recommend the routine use of ultrasound scanning.

Sonographic spinal imaging of normal anatomy, pathology and magnetic growing rods in children

The wide availability of ultrasound, along with its lack of ionizing radiation burden and need for sedation for most exams, often make sonography the first line in the imaging evaluation of children. The developing osseous anatomy of the spine in young infants provides a distinct window allowing for a detailed depiction of the spinal canal and its contents, which is not present in older children or adults. Here we review the clinical indications, sonographic technique, normal anatomy and pathology for imaging the lumbosacral spine in neonates and young infants. Additionally, we review the procedure for ultrasound assessment of the lengthening of magnetically controlled growing spinal rods, which allows orthopedists and radiologists to evaluate the effectiveness of distraction procedures of this hardware without the use of ionizing radiation.

Quantitative analysis of cranial ultrasonographic periventricular echogenicity in relation to early neuromotor development in preterm infants

BACKGROUND

Periventricular white matter (WM) hyperechoic flares that do not evolve into cystic lesion(s) are frequently encountered on cranial ultrasonography (CUS) of preterm infants. Subjective interpretation of its presence, however, is challenging and its association with maturation and neurodevelopment remains undefined.

OBJECTIVES

To determine the relationship between quantitative WM echogenicity and postnatal and postmenstrual ages and the relationship between quantitative WM echogenicity and neuromotor development at term equivalent.

METHODS

We measured the mean pixel brightness intensity at the frontoparietal and parieto-occipital WM, choroid plexus and calvarium bone on sequential neonatal CUS scans of preterm infants born at <34 weeks gestation. The relative echogenicity (RE) was derived by dividing the mean WM echogenicity to that of the choroid plexus (RE(CP)) or bone (RE(BN)). The Lacey Assessment of the Preterm Infant was administered before discharge.

RESULTS

58 preterm infants (the mean gestational age 30.6±2.3 weeks and the mean birth weight 1211.9±224.7 g) were included. The RE(CP) of the frontoparietal WM decreased significantly with advancing postnatal and postmenstrual ages (r=-0.4, p<0.0001). The RE(BN) values of the frontoparietal and parieto-occipital WM during intermediate and late predischarge CUS studies, respectively, were significantly associated with neuromotor status at term (p<0.05). The RE(CP) and RE(BN) measured during the first week of life were not associated with neuromotor status at term.

CONCLUSIONS

Quantitative measurements of the periventricular WM echogenicity are feasible in neonatal CUSs of premature infants and may reflect microstructural developmental changes. An optimal echogenicity quantification technique and its correlation with long-term outcome remain to be determined.

[Ultrasound examination in childhood: new perspectives]

Everyday use of the modern imaging techniques such as CT, MRI, isotope, PET/CT decreased the reputation and importance of ultrasound. In some cases, ultrasound is only the first exploratory imaging method. Using the latest multi-slice CT, imaging can be performed in seconds, which led to a dramatic increase in the number of CT exams. However, this also means a significant radiation exposure to children, while US still harmless in this regard. In addition, significant progress has been made in ultrasound technology in recent years, which led an improvement in image quality. Children are ideal subjects for US examination as they usually have smaller weight with less body fat. Thus, ultrasound examination is easy to perform with a high frequency transducer resulting in much more detailed and higher resolution than in adults. With adequate equipment and experienced examiner in pediatric radiology, almost all parts of the body can be examined, making this technique as the first (sometimes together with X-ray) and, in most cases, the ultimate imaging exam for the diagnosis. This article will discuss the possibilities where ultrasound performed with a modern device is sufficient for an accurate diagnosis.

Head Ultrasound and MR imaging in the evaluation of neonatal encephalopathy: competitive or complementary imaging studies?

Magnetic resonance (MR) imaging is superior to ultrasonography (US) for the evaluation and prognostication of neonates with neonatal encephalopathy (NE). Nonetheless, US may provide important information early in the course of NE and can be used to document the evolution of lesions. This article provides an overview of useful findings in the US evaluation of infants with NE. Although many of the findings do not appear as conspicuous or as extensively as they do on MR imaging, recognition and familiarity with subtle head US abnormalities may allow head US to play an important complementary role to MR imaging in the evaluation of infants with NE.