Cranial ultrasound in the detection of intracranial calcifications

How to look for intracranial calcification in children with neurological disorders: CT, MRI, or both of them?

BACKGROUND

Intracranial calcification (ICC) is an important diagnostic clue in pediatric neurology. Considering the radiation-induced cancer risk associated with computed tomography (CT), we aim to define the diagnostic value of magnetic resonance imaging (MRI) sequences sensitive to paramagnetic/diamagnetic substances in the detection of ICC, comparing with CT scanning.

MATERIALS AND METHODS

We selected MRI and CT scans performed in children affected by neurological conditions associated with ICC referred to the participating centers between 2005 and 2018. Inclusion criteria were age at neuroradiological investigation < 18 years, availability of good quality CT positive for calcification, and MRI scan that included GE or/and SWI sequences, performed no more than 6 months apart.

RESULTS

Eighty-one patients were included in the study. CT and MRI scans were reviewed by consensus. MRI failed to detect ICC in 14% of the cases. Susceptibility-weighted imaging (SWI) was the best MRI sequence to use in this setting, followed by gradient echo imaging. In 19% of the cases, CT could have been avoided because the identification or monitoring of ICC has not been necessary for the clinical management of the patient.

CONCLUSION

In the diagnostic workup of pediatric-onset neurological disorders of unknown cause, the first step to look for ICC should be an MRI that includes SWI and GE sequences. If ICC is absent on MRI, brain CT scanning should be performed at least once. When the identification or monitoring of ICC is unlikely to add information useful for patient's follow-up or treatment, we recommend not performing CT scanning.

Agreement between ultrasonography and computed tomography in detecting intracranial calcifications in congenital toxoplasmosis

AIM

To evaluate the agreement between ultrasound (US) and computed tomography (CT) in detecting intracranial calcification in infants with congenital toxoplasmosis.

MATERIALS AND METHODS

Forty-four infants referred for investigation of congenital toxoplasmosis were prospectively evaluated, and the diagnosis was confirmed or ruled out by serological testing and by follow-up in the first year of life. The investigation protocol included cranial US and cranial CT, and examinations were conducted and interpreted by two radiologists blinded to the results of the other imaging test and to the diagnostic confirmation.

RESULTS

The diagnosis of congenital toxoplasmosis was confirmed in 33 patients, and agreement between US and CT findings was found in 31 of these cases. Both methods detected calcifications in 18 patients, and neither detected calcifications in 13 patients. Overall agreement was 94% and the kappa coefficient was 0.88 (95% confidence interval: 0.71, 1; p<0.001), which revealed almost perfect agreement between the two diagnostic methods.

CONCLUSION

In this study, US and CT demonstrated equal sensitivity in the detection of intracranial calcification in infants with congenital toxoplasmosis.

Prognostic significance of hyperechogenic lesions in the basal ganglia and thalamus in neonates

Neonatal cranial ultrasonography at times reveals hyperechogenic lesions in the basal ganglia and thalamus. These lesions have been attributed to a wide variety of pathologic states, among them toxoplasmosis, rubella, cytomegalovirus, and herpes simplex (TORCH) infections, chromosomal abnormalities, and asphyxia. The clinical significance in terms of the neurodevelopmental outcome of this radiologic abnormality is unknown. We performed a developmental evaluation on 16 children aged 2 to 6 years in whom neonatal cranial ultrasonography had demonstrated hyperechogenic lesions in the basal ganglia or thalamus and had no other neurodevelopmental risk factors. There was no significant difference between the average Developmental Quotient of the target population and the normal population in regard to developmental status. We conclude that in our population, an isolated finding of hyperechogenic lesions in the basal ganglia is probably not a predictor of poor neurodevelopmental outcome.

Osteopetrosis: brain ultrasound and computed tomography findings

A case of osteopetrosis presenting with rare features of dysmorphism with proptosis due to hypoplasia of the orbits and the temporal bone is described. The case also had calcifications in the periventricular regions, the falx cerebri and the corpora colliculi. These features and sonographic findings of osteopetrosis have not been reported previously. The sensitivity and specificity of imaging modalities in the diagnosis of intracranial calcifications is discussed.

Congenital infections and the nervous system

Despite vaccines, new antimicrobials, and improved hygienic practices, congenital infections remain an important cause of death and long-term neurologic morbidity among infants world-wide. Important agents include Toxoplasma gondii, cytomegalovirus, Treponema pallidum, herpes simplex virus types 1 and 2, and rubella virus. In addition, several other agents, such as the varicella zoster virus, human parvovirus B19, and Borrelia burgdorferi, can potentially infect the fetus and cause adverse fetal outcomes. This article provides an overview of these infectious disorders and outlines current strategies for acute treatment and long-term management.

Hyperechoic lesions in the basal ganglia: an incidental sonographic finding in neonates and infants

Cerebral ultrasound (US) imaging was performed as a screening procedure in approximately 3,600 neonates and infants over a period of 18 months. Hyperechoic lesions in the basal ganglia and thalamic region were detected incidentally in 15 of these patients. Clinical diagnoses included cytomegalovirus infection, asphyxia, rotavirus infection, prematurity, amniotic infection, dysmorphic stigmata, hyperbilirubinemia, congenital heart disease, and diabetic fetopathia. Lesions showed a single punctate (n = 5), multiple punctate (n = 8), or stripe-like pattern (n = 2), with no disease-specific distribution. Computed tomography performed in two of the 15 patients was normal. Lesions resolved within four to seven months in four of eleven cases who had follow-up studies, whereas echogenicities persisted in the remaining seven patients over a period of observation ranging between one to 15 months. Our results indicate that hyperechoic lesions in the basal ganglia and thalamic region may be associated with congenital infections and asphyxia, but could indicate some other unknown pathology. No correlation was found between the morphology of foci and both clinical diagnosis and results of follow-up studies.

Demonstration of perivascular echogenicities in congenital cytomegalovirus infection by colour Doppler imaging

Two children with congenital cytomegalovirus infection and intracerebral echogenicities were investigated by computer sonography and colour Doppler imaging (CDI). By simultaneous imaging of brain tissue and CDI, blood flow within the stripe-like echogenicities of the basal ganglia was demonstrated. Using CDI the echogenicities were identified as the walls of thalamostriate vessels.

Outcome in children with symptomatic congenital cytomegalovirus infection

To determine factors that are associated with adverse developmental outcome after congenital cytomegalovirus infection, we reviewed the clinical, laboratory, and radiographic findings in 18 children with symptomatic congenital cytomegalovirus infections. When children with adverse outcomes (intelligence or developmental quotients of 50 or less, n = 10) were compared with children with mild sequelae (intelligence or developmental quotients of 70 or higher, n = 8), we found no relationship between developmental outcome and neonatal clinical features (birth weight, jaundice, hepatomegaly, splenomegaly, or petechiae). With the possible exception of intracranial calcifications, no single clinical or radiographic feature was associated with a specific developmental outcome. However, children who had postnatal microcephaly, postnatal seizures, and an abnormal central nervous system imaging study were more likely to have severe developmental sequelae.

Diagnosis of brain neuropathology in utero

The fetal brain can be evaluated very effectively with high-resolution real-time ultrasound equipment. This paper reviews normal fetal brain anatomy with specific emphasis on artifacts of ultrasound scanning of the brain. A review of the developmental abnormalities seen in utero include ventriculomegaly, anencephaly, encephalocele, meningomyelocele, Dandy-Walker syndrome, holoprosencephaly, craniosynostosis, microcephaly, and agenesis of the corpus callosum. The destructive lesions reviewed include hydranencephaly, infection, intracranial hemorrhage, and mass lesion. Identification of these abnormalities can be extremely helpful in providing the patients with management options and providing the obstetrician with information which can help in obstetric and neonatal therapy.

Cranial ultrasound in the detection of postmeningitic complications in the neonates

Serial cranial ultrasound examinations were performed through the anterior fontanel to detect and follow the complications of bacterial meningitis in 16 neonates. The final results included normal findings in 9 patients, and abnormal in the other 7 cases. Among the latter, 5 patients with hydrocephalus were sequentially found after the second week of the disease and the earlier the onset, the larger the ventricular dilation. One ventriculitis showed polycystic loculi with abnormal septa in the advanced stage. Cystic low attenuation lesion with mass effect at a later stage of meningitis specified one patient with brain abscess. Progressive dilatation of ventricular systems without associated growth of head girth disclosed a process of brain atrophy. They had neither obvious neurological signs nor specific CSF findings clinically, but their sonograms showed the abnormal changes which were finally proved by CT scans. The potential value of cranial ultrasound in the detection of post-meningitic complication besides CT scan is stressed.