Medullary Tegmental Cap Dysplasia: Fetal and Postnatal Presentations of a Unique Brainstem Malformation

BACKGROUND AND PURPOSE

Medullary tegmental cap dysplasia is a rare brainstem malformation, first described and defined by James Barkovich in his book Pediatric Neuroimaging from 2005 as an anomalous mass protruding from the posterior medullary surface. We describe the neuroimaging, clinical, postmortem, and genetic findings defining this unique malformation.

MATERIALS AND METHODS

This is a multicenter, international, retrospective study. We assessed the patients' medical records, prenatal ultrasounds, MR images, genetic findings, and postmortem results. We reviewed the medical literature for all studies depicting medullary malformations and evaluated cases in which a dorsal medullary protuberance was described.

RESULTS

We collected 13 patients: 3 fetuses and 10 children. The medullary caps had multiple characteristics. Associated brain findings were a rotated position of the medulla, a small and flat pons, cerebellar anomalies, a molar tooth sign, and agenesis of the corpus callosum. Systemic findings included the following: polydactyly, hallux valgus, large ears, and coarse facies. Postmortem analysis in 3 patients revealed that the cap contained either neurons or white matter tracts. We found 8 publications describing a dorsal medullary protuberance in 27 patients. The syndromic diagnosis was Joubert-Boltshauser syndrome in 11 and fibrodysplasia ossificans progressiva in 14 patients.

CONCLUSIONS

This is the first study to describe a series of 13 patients with medullary tegmental cap dysplasia. The cap has different shapes: distinct in Joubert-Boltshauser syndrome and fibrodysplasia ossificans progressive. Due to the variations in the clinical, imaging, and postmortem findings, we conclude that there are multiple etiologies and pathophysiology. We suggest that in some patients, the pathophysiology might be abnormal axonal guidance.

Imaging Characteristics of CNS Neuroblastoma-FOXR2: A Retrospective and Multi-Institutional Description of 25 Cases

BACKGROUND AND PURPOSE

The 5th edition of the World Health Organization Classification of CNS tumors defines the CNS neuroblastoma FOXR2 in the group of embryonal tumors. Published clinical outcomes tend to suggest a favorable outcome after resection, craniospinal irradiation, and chemotherapy. This multicenter study aimed to describe imaging features of CNS neuroblastoma-FOXR2, which have been poorly characterized thus far.

MATERIALS AND METHODS

On the basis of a previously published cohort of tumors molecularly classified as CNS neuroblastoma-FOXR2, patients with available imaging data were identified. The imaging features on preoperative MR imaging and CT data were recorded by 8 experienced pediatric neuroradiologists in consensus review meetings.

RESULTS

Twenty-five patients were evaluated (13 girls; median age, 4.5 years). The tumors were often large (mean, 115 [ SD, 83] mL), showed no (24%) or limited (60%) perilesional edema, demonstrated heterogeneous enhancement, were often calcified and/or hemorrhagic (52%), were always T2WI-hyperintense to GM, and commonly had cystic and/or necrotic components (96%). The mean ADC values were low (687.8 [SD 136.3] × 10-6 mm2/s). The tumors were always supratentorial. Metastases were infrequent (20%) and, when present, were of nodular appearance and leptomeningeal.

CONCLUSIONS

In our cohort, CNS neuroblastoma FOXR2 tumors showed imaging features suggesting high-grade malignancy and, at the same time, showed characteristics of less aggressive behavior. There are important differential diagnoses, but the results of this study may assist in considering this diagnosis preoperatively.

Resting energy expenditure in children at risk of hypothalamic dysfunction

OBJECTIVE

Children with suprasellar brain damage are at risk of hypothalamic dysfunction (HD). HD may lead to decreased resting energy expenditure (REE). Decreased REE, however, is not present in all children with HD. Our aim was to assess which children suspect for HD have low REE, and its association with clinical severity of HD or radiological hypothalamic damage.

PATIENTS AND METHODS

A retrospective cohort study was performed. Measured REE (mREE) of children at risk of HD was compared to predicted REE (pREE). Low REE was defined as mREE <90% of predicted. The mREE/pREE quotient was associated to a clinical score for HD symptoms and to radiological hypothalamic damage.

RESULTS

In total, 67 children at risk of HD (96% brain tumor diagnosis) with a mean BMI SDS of +2.3 ± 1.0 were included. Of these, 45 (67.2%) had low mREE. Children with severe HD had a significant lower mean mREE/pREE quotient compared to children with no, mild, or moderate HD. Mean mREE/pREE quotient of children with posterior hypothalamic damage was significantly lower compared to children with no or anterior damage. Tumor progression or tumor recurrence, severe clinical HD, and panhypopituitarism with diabetes insipidus (DI) were significant risk factors for reduced REE.

CONCLUSION

REE may be lowered in children with hypothalamic damage and is associated to the degree of clinical HD. REE is, however, not lowered in all children suspect for HD. For children with mild or moderate clinical HD symptoms, REE measurements may be useful to distinguish between those who may benefit from obesity treatment that increases REE from those who would be better helped using other obesity interventions.

The atonic stomach: a dangerous condition prior to scoliosis surgery

A dilated atonic stomach as part of neuromuscular or syndromic disorders can have devastating results after scoliosis surgery. Patients can be asymptomatic preoperatively and non-clinical signs can be easily overlooked. Awareness of the condition, however, can prevent severe complications such as aspiration.

The Mammillary Bodies: A Review of Causes of Injury in Infants and Children

Despite their small size, the mammillary bodies play an important role in supporting recollective memory. However, they have typically been overlooked when assessing neurologic conditions that present with memory impairment. While there is increasing evidence of mammillary body involvement in a wide range of neurologic disorders in adults, very little attention has been given to infants and children. Literature searches of PubMed and EMBASE were performed to identify articles that describe mammillary body pathology on brain MR imaging in children. Mammillary body pathology is present in the pediatric population in several conditions, indicated by signal change and/or atrophy on MR imaging. The main causes of mammillary body pathology are thiamine deficiency, hypoxia-ischemia, direct damage due to masses or hydrocephalus, or deafferentation resulting from pathology within the wider Papez circuit. Optimizing scanning protocols and assessing mammillary body status as a standard procedure are critical, given their role in memory processes.

Neurological deficits are present in syndromic craniosynostosis patients with and without tonsillar herniation

BACKGROUND

Children with syndromic craniosynostosis (sCS) have a higher incidence of cerebellar tonsillar herniation (TH) than the general population. In the general population, TH ≥ 5 mm below the foramen magnum is associated with typical neurological deficits but, in sCS, we do not know whether this degree of TH is required before such deficits occur.

OBJECTIVE

This prospective cohort study aimed to determine the association between findings on neurological assessment and cerebellar tonsillar position.

METHODS

Magnetic resonance imaging (MRI) was used to determine TH ≥ 5 mm and the presence of syringomyelia. In regard to the outcome of neurological deficits, these were categorized according to: A, cerebellar function; B, cranial nerve abnormalities; and C, sensory or motor dysfunction.

RESULTS

Twenty of 63 patients with sCS (32% [95% confidence interval 21-45%]) had TH ≥ 5 mm and/or syringomyelia. There was no significant difference in proportion between individual forms of sCS: 16/34 Crouzon, 2/11 Muenke, 2/12 Apert, and 0/7 Saethre-Chotzen patients. Neurological deficits were prevalent (73% [95% confidence interval 60-83%]), and as frequent in patients with TH ≥ 5 mm and/or syringomyelia as those without. Surgery occurred in 3 patients overall, and only in Crouzon patients.

CONCLUSION

Determining the effect of TH ≥ 5 mm on neurologic functioning in sCS patients is used to better determine when surgical intervention is warranted. However, we have found that neurological deficits are prevalent in sCS patients, irrespective of cerebellar tonsillar position, suggesting that such findings are developmental and, in part, syndrome-specific central nervous system features.

A New Ultrasound Marker for Bedside Monitoring of Preterm Brain Growth

BACKGROUND AND PURPOSE

Preterm neonates are at risk for neurodevelopmental impairment, but reliable, bedside-available markers to monitor preterm brain growth during hospital stay are still lacking. The aim of this study was to assess the feasibility of corpus callosum-fastigium length as a new cranial sonography marker for monitoring of preterm brain growth.

MATERIALS AND METHODS

In this longitudinal prospective cohort study, cranial ultrasound was planned on the day of birth, days 1, 2, 3, and 7 of life; and then weekly until discharge in preterm infants born before 29 weeks of gestational age. Reproducibility and associations between clinical variables and corpus callosum-fastigium growth trajectories were studied.

RESULTS

A series of 1-8 cranial ultrasounds was performed in 140 infants (median gestational age at birth, 27(+2) weeks (interquartile range, 26(+1) to 28(+1); 57.9% male infants). Corpus callosum-fastigium measurements showed good-to-excellent agreement for inter- and intraobserver reproducibility (intraclass correlation coefficient >0.89). Growth charts for preterm infants between 24 and 32 weeks of gestation were developed. Male sex and birth weight SD score were positively associated with corpus callosum-fastigium growth rate.

CONCLUSIONS

Corpus callosum-fastigium length measurement is a new reproducible marker applicable for bedside monitoring of preterm brain growth during neonatal intensive care stay.

Diffusion Tensor Imaging and Fiber Tractography in Children with Craniosynostosis Syndromes

BACKGROUND AND PURPOSE

Patients with craniosynostosis syndromes caused by mutations in FGFR-2, FGFR-3, and TWIST1 genes are characterized by having prematurely fused skull sutures and skull base synchondroses, which result in a skull deformity and are accompanied by brain anomalies, including altered white matter microarchitecture. In this study, the reliability and reproducibility of DTI fiber tractography was investigated in these patients. The outcomes were compared with those of controls.

MATERIALS AND METHODS

DTI datasets were acquired with a 1.5T MR imaging system with 25 diffusion gradient orientations (voxel size = 1.8 × 1.8 × 3.0 mm(3), b-value = 1000 s/mm(2)). White matter tracts studied included the following: corpus callosum, cingulate gyrus, fornix, corticospinal tracts, and medial cerebellar peduncle. Tract pathways were reconstructed with ExploreDTI in 58 surgically treated patients with craniosynostosis syndromes and 7 controls (age range, 6-18 years).

RESULTS

Because of the brain deformity and abnormal ventricular shape and size, DTI fiber tractography was challenging to perform in patients with craniosynostosis syndromes. To provide reliable tracts, we adapted standard tracking protocols. Fractional anisotropy was equal to that in controls (0.44 versus 0.45 ± 0.02, P = .536), whereas mean, axial, and radial diffusivity parameters of the mean white matter were increased in patients with craniosynostosis syndromes (P < .001). No craniosynostosis syndrome-specific difference in DTI properties was seen for any of the fiber tracts studied in this work.

CONCLUSIONS

Performing DTI fiber tractography in patients with craniosynostosis syndromes was difficult due to partial volume effects caused by an anisotropic voxel size and deformed brain structures. Although these patients have a normal fiber organization, increased diffusivity parameters suggest abnormal microstructural tissue properties of the investigated white matter tracts.

Atypical presentation of a newborn with Apert syndrome

INTRODUCTION

Apert syndrome is a rare syndrome characterized by a consistent phenotype including bilateral coronal suture synostosis with an enlarged anterior fontanel, midface hypoplasia, and complex symmetric syndactyly of hands and feet.

CASE REPORT

We present a boy with Apert syndrome caused by the pathogenic c.755C > G p.Ser252Trp mutation in the FGFR2 gene with atypical characteristics, including premature fusion of the metopic suture with a small anterior fontanel, hypotelorism, and a massive posterior fontanel. Directly after birth, he showed papilledema, epilepsy, and central apneas.

CONCLUSION

We present a newborn with Apert syndrome with atypical craniofacial presentation.

Choice of diffusion tensor estimation approach affects fiber tractography of the fornix in preterm brain

BACKGROUND AND PURPOSE

Neonatal DTI enables quantitative assessment of microstructural brain properties. Although its use is increasing, it is not widely known that vast differences in tractography results can occur, depending on the diffusion tensor estimation methodology used. Current clinical work appears to be insufficiently focused on data quality and processing of neonatal DTI. To raise awareness about this important processing step, we investigated tractography reconstructions of the fornix with the use of several estimation techniques. We hypothesized that the method of tensor estimation significantly affects DTI tractography results.

MATERIALS AND METHODS

Twenty-eight DTI scans of infants born <29 weeks of gestation, acquired at 30-week postmenstrual age and without intracranial injury observed, were prospectively collected. Four diffusion tensor estimation methods were applied: 1) linear least squares; 2) weighted linear least squares; 3) nonlinear least squares, and 4) robust estimation of tensors by outlier rejection. Quality of DTI data and tractography results were evaluated for each method.

RESULTS

With nonlinear least squares and robust estimation of tensors by outlier rejection, significantly lower mean fractional anisotropy values were obtained than with linear least squares and weighted linear least squares. Visualized quality of tract reconstruction was significantly higher by use of robust estimation of tensors by outlier rejection and correlated with quality of DTI data.

CONCLUSIONS

Quality assessment and choice of processing methodology have considerable impact on neonatal DTI analysis. Dedicated acquisition, quality assessment, and advanced processing of neonatal DTI data must be ensured before performing clinical analyses, such as associating microstructural brain properties with patient outcome.

Optimal timing of cerebral MRI in preterm infants to predict long-term neurodevelopmental outcome: a systematic review

SUMMARY

Advances in neonatal neuroimaging have improved detection of preterm brain injury responsible for abnormal neuromotor and cognitive development. Increasingly sophisticated MR imaging setups allow scanning during early preterm life. In this review, we investigated how brain MR imaging in preterm infants should be timed to best predict long-term outcome. Given the strong evidence that structural brain abnormalities are related to long-term neurodevelopment, MR imaging should preferably be performed at term-equivalent age. Early MR imaging is promising because it can guide early intervention studies and is indispensable in research on preterm brain injury.

Determination of the optimal length of insertion of central venous catheters in pediatric patients by endovascular ECG

BACKGROUND

In children the position of the tip of central venous catheters (CVC) is most often examined by chest radiography. Endovascular electrocardiography (ECG), using the CVC as an electrode, permits the correct placement of a CVC without the need for a chest X-ray. The use of a commercialised endovascular ECG-system (Alphacard®) for CVC-placement was evaluated in pediatric patients.

METHODS

ECG-guidance was prospectively applied in 50 children (0-17 years, stratified into 5 age related subgroups). Positioning of the CVC was performed under ECG-guidance and subsequently assessed by chest X-ray. The frequency of correct ECG-guided CVC-placement in one single attempt, duration until confirmation by ECG and X-ray, and body weight-related depth of CVC-insertion were assessed.

RESULTS

In 44 patients ECG-guidance resulted in a correct placement of the CVC-tip. Duration (median and [IQR] in sec.) to confirmation of correct placement was shorter with the ECG method (78[49-136]) than with X-ray (720[249-1095]) (P<0.0001). In five patients the ECG method failed because the CVC chosen was too short or the anesthetist did not trust the ECG-method. In one patient an unknown anatomical anomaly was present. Depth of insertion of the CVC was positively correlated with body weight (r2 0.68, P<0.0001). Stratification for age had no impact on duration until confirmation of CVC-position. No complications occurred during CVC-placement.

CONCLUSION

ECG guidance of CVC-placement in children is a reliable technique, preventing children and health care providers from unnecessary X-ray exposure. Depending on local infrastructure and protocols it can furthermore shorten the procedure of CVC placement.

Acquisition guidelines and quality assessment tools for analyzing neonatal diffusion tensor MRI data

Diffusion tensor imaging is a valuable measure in clinical settings to assess diagnosis and prognosis of neonatal brain development. However, obtaining reliable images is not straightforward because of the tissue characteristics of the neonatal brain and the high likelihood of motion artifacts. In this review, we present guidelines on how to acquire DTI data of the neonatal brain and recommend high-quality data acquisition and processing as an essential means to obtain accurate and robust parametric maps. Sudden head movements are problematic for DTI in neonates, and these may lead to incorrect values. We describe strategies to minimize the corrupting effects both in terms of acquisition (eg, more gradient directions) and postprocessing (eg, tensor estimation methods). In addition, tools are described that can help assess whether a dataset is of sufficient quality for further assessment.

Cognitive outcome of patients with classic infantile Pompe disease receiving enzyme therapy

OBJECTIVE

Classic infantile Pompe disease affects many tissues, including the brain. Untreated infants die within their first year. Although enzyme-replacement therapy (ERT) significantly increases survival, its potential limitation is that the drug cannot cross the blood-brain barrier. We therefore investigated long-term cognitive development in patients treated with ERT.

METHODS

We prospectively assessed cognitive functioning in 10 children with classic infantile Pompe disease who had been treated with ERT since 1999. Brain imaging was performed in 6 children.

RESULTS

During the first 4 years of life, developmental scores in 10 children ranged from above-average development to severe developmental delay; they were influenced by the type of intelligence test used, severity of motor problems, speech/language difficulties, and age at start of therapy. Five of the children were also tested from 5 years onward. Among them were 2 tetraplegic children whose earlier scores had indicated severe developmental delay. These scores now ranged between normal and mild developmental delay and indicated that at young age poor motor functioning may interfere with proper assessment of cognition. We found delayed processing speed in 2 children. Brain imaging revealed periventricular white matter abnormalities in 4 children.

CONCLUSIONS

Cognitive development at school age ranged between normal and mildly delayed in our long-term survivors with classic infantile Pompe disease treated with ERT. The oldest was 12 years. We found that cognition is easily underestimated in children younger than 5 years with poor motor functioning.

Brain and ventricular volume in patients with syndromic and complex craniosynostosis

PURPOSE

Brain abnormalities in patients with syndromic craniosynostosis can either be a direct result of the genetic defect or develop secondary to compression due to craniosynostosis, raised ICP or hydrocephalus. Today it is unknown whether children with syndromic craniosynostosis have normal brain volumes. The purpose of this study was to evaluate brain and ventricular volume measurements in patients with syndromic and complex craniosynostosis. This knowledge will improve our understanding of brain development and the origin of raised intracranial pressure in syndromic craniosynostosis.

METHODS

Brain and ventricular volumes were calculated from MRI scans of patients with craniosynostosis, 0.3 to 18.3 years of age. Brain volume was compared to age matched controls from the literature. All patient charts were reviewed to look for possible predictors of brain and ventricular volume.

RESULTS

Total brain volume in syndromic craniosynostosis equals that of normal controls, in the age range of 1 to 12 years. Brain growth occurred particularly in the first 5 years of age, after which it stabilized. Within the studied population, ventricular volume was significantly larger in Apert syndrome compared to all other syndromes and in patients with a Chiari I malformation.

CONCLUSIONS

Patients with syndromic craniosynostosis have a normal total brain volume compared to normal controls. Increased ventricular volume is associated with Apert syndrome and Chiari I malformations, which is most commonly found in Crouzon syndrome. We advice screening of all patients with Apert and Crouzon syndrome for the development of enlarged ventricle volume and the presence of a Chiari I malformation.

Distinctive Phenotypic Abnormalities Associated with Submicroscopic 21q22 Deletion Including DYRK1A

Partial monosomy 21 has been reported, but the phenotypes described are variable with location and size of the deletion. We present 2 patients with a partially overlapping microdeletion of 21q22 and a striking phenotypic resemblance. They both presented with severe psychomotor delay, behavioral problems, no speech, microcephaly, feeding problems with frequent regurgitation, idiopathic thrombocytopenia, obesity, deep set eyes, down turned corners of the mouth, dysplastic ears, and small chin. Brain MRI showed cerebral atrophy mostly evident in frontal and temporal lobes, widened ventricles and thin corpus callosum in both cases, and in one patient evidence of a migration disorder. The first patient also presented with epilepsy and a ventricular septum defect. The second patient had a unilateral Peters anomaly. Microarray analysis showed a partially overlapping microdeletion spanning about 2.5 Mb in the 21q22.1-q22.2 region including the DYRK1A gene and excluding RUNX1. These patients present with a recognizable phenotype specific for this 21q22.1-q22.2 locus. We searched the literature for patients with overlapping deletions including the DYRK1A gene, in order to define other genes responsible for this presentation.

Self-limiting sternal tumors of childhood (SELSTOC)

BACKGROUND

Because a sternal mass is often alarming, it is important to identify the clinical features of benign processes.

PROCEDURE

Data on clinical presentation, diagnostics, treatment and outcome of pediatric patients presenting with a sternal tumor between 2001 and 2009 were collected from medical records.

RESULTS

Among the 1,700 children who were referred to our pediatric-oncology center, 14 presented with a rapidly growing sternal mass. All patients (10 males) were Caucasian and median age was 16 (range: 7-50) months. Reported symptoms were local pain (n = 7) and/or raised body temperature (n = 5). No major preceding traumas were reported. Physical examination revealed solid tumors with a median diameter of 3 (range: 1-4.5) cm in a pre-sternal/para-sternal location. Half of the patients showed red/blue discoloration of the skin. On radiology, dumbbell-shaped lesions extended to the area behind the sternal bone, involving the cartilage, leading to increased distance between ossification centers. Histopathology at diagnosis was available from five patients and showed aspecific chronic or acute inflammation (n = 4) and a reactive osteochondromatous lesion (n = 1). Laboratory infection parameters were not/only slightly raised and microbiologic cultures were negative in all patients. All tumors decreased in size within 1 month, in both patients with and without antibiotics. On physical examination the tumors disappeared within 6 months.

CONCLUSIONS

This study reports 14 young children with a rapidly growing sternal mass due to aseptic inflammation, that we named self-limiting sternal tumor of childhood (SELSTOC). To prevent invasive diagnostic interventions and unnecessary treatment, we advocate a wait-and-see approach with close follow-up in the first weeks.

Abdominal fat in children measured by ultrasound and computed tomography

The prevalence of childhood obesity is increasing rapidly. Visceral fat plays an important role in the pathogenesis of metabolic and cardiovascular diseases. Currently, computed tomography (CT) is broadly seen as the most accurate method of determining the amount of visceral fat. The main objective was to examine whether measures of abdominal visceral fat can be determined by ultrasound in children and whether CT can be replaced by ultrasound for this purpose. To assess whether preperitoneal fat thickness and area are good approximations of visceral fat at the umbilical level, we first retrospectively examined 47 CT scans of nonobese children (body mass index <30kg/m(2); median age 7.9 y [95% range 1.2 to 16.2]). Correlation coefficients between visceral and preperitoneal fat thickness and area were 0.58 (p<0.001) and 0.76 (p<0.001), respectively. Then, to assess how preperitoneal and subcutaneous fat thicknesses and areas measured by ultrasound compare with these parameters in CT, we examined 34 nonobese children (median age 9.5 [95% range 0.3 to 17.0]) by ultrasound and CT. Ultrasound measurements of preperitoneal and subcutaneous fat were correlated with CT measurements, with correlation coefficients ranging from 0.75-0.97 (all p<0.001). Systematic differences of up to 24.0cm(2) for preperitoneal fat area (95% confidence interval -29.9 to 77.9cm(2)) were observed when analyzing the results described by the Bland-Altman method. Our findings suggest that preperitoneal fat can be used as an approximation for visceral fat in children and that measuring abdominal fat with ultrasound in children is a valid method for epidemiological and clinical studies. However, the exact agreement between the ultrasound and CT scan was limited, which indicates that ultrasound should be used carefully for obtaining exact fat distribution measurements in individual children.

Magnetic resonance imaging in neonatal stroke

Neonatal stroke occurs in 1 in 2300-5000 live births, the incidence of which is lower than that in adults, but still higher than that in childhood. The higher incidence of perinatal stroke in preterm and term infants compared to stroke in childhood may be partly explained by higher detection rates using routine fetal ultrasound and postnatal cranial sonography. In addition, there is greater availability of magnetic resonance imaging (MRI) for neuroimaging in preterm and full-term infants, which is due in part to the availability of MR-compatible incubators and MR systems at or near the neonatal intensive care unit. In addition, the wide range of MR techniques, such as T2-, diffusion- and susceptibility-weighted imaging allows improved visualization and quantification of neonatal stroke or hypoxic-ischemic injury. This chapter reviews the MR neuroimaging modalities that actually assist the clinician in the detection of neonatal stroke.

Movement disorder and neuronal migration disorder due to ARFGEF2 mutation

We report a child with a severe choreadystonic movement disorder, bilateral periventricular nodular heterotopia (BPNH), and secondary microcephaly based on compound heterozygosity for two new ARFGEF2 mutations (c.2031_2038dup and c.3798_3802del), changing the limited knowledge about the phenotype. The brain MRI shows bilateral hyperintensity of the putamen, BPNH, and generalized atrophy. Loss of ARFGEF2 function affects vesicle trafficking, proliferation/apoptosis, and neurotransmitter receptor function. This can explain BPNH and microcephaly. We hypothesize that the movement disorder and the preferential damage to the basal ganglia, specifically to the putamen, may be caused by an increased sensitivity to degeneration, a dynamic dysfunction due to neurotransmitter receptor mislocalization or a combination of both.

Quantitative differentiation between healthy and disordered brain matter in patients with neurofibromatosis type I using diffusion tensor imaging

BACKGROUND AND PURPOSE

Hyperintensities on T2-weighted images are seen in the brains of most patients with neurofibromatosis type I (NF-1), but the origin of these unidentified bright objects (UBOs) remains obscure. In the current study, we examined the diffusion characteristics of brain tissue in children with NF-1 to test the hypothesis that a microstructural abnormality is present in NF-1.

MATERIALS AND METHODS

Diffusion tensor imaging (DTI) was performed in 50 children with NF-1 and 8 controls. Circular regions of interest were manually placed in 7 standardized locations in both hemispheres, including UBO sites. Apparent diffusion coefficients (ADC), fractional anisotropy (FA), and axial anisotropy (A(m)) were used to differentiate quantitatively between healthy and disordered brain matter. Differences in eigenvalues (lambda(1), lambda(2), lambda(3)) were determined to examine parenchymal integrity.

RESULTS

We found higher ADC values for UBOs than for normal-appearing sites (P < .01) and higher ADC values for normal-appearing sites than for controls (P < .04 in 5 of 7 regions). In most regions, we found no differences in FA or A(m). Eigenvalues lambda(2) and lambda(3) were higher at UBO sites than in normal-appearing sites (P < .04).

CONCLUSION

With ADC, it was possible to differentiate quantitatively between normal- and abnormal-appearing brain matter in NF-1 and also between normal-appearing brain matter in NF-1 and healthy brain matter in controls, indicating subtle pathologic damage disrupting the tissue microstructure in the NF-1 brain. Higher diffusivity for lambda(1), lambda(2), and lambda(3) indicates that this disturbance of microstructure is caused by accumulation of fluid or vacuolation.

Microcephaly and simplified gyral pattern of the brain associated with early onset insulin-dependent diabetes mellitus

Two families are presented with a child suffering from microcephaly with a simplified gyral pattern of the brain (SGP) and early onset insulin dependent diabetes mellitus (IDDM). The first patient was diagnosed postmortally with Wolcott-Rallison syndrome, after her younger brother developed IDDM, and a homozygous mutation in the eukaryotic translation initiation factor 2-alpha kinase 3 was found. The younger brother did not undergo magnetic resonance imaging (MRI). The patient from the second family has no EIF2AK3 mutation. SGP is considered to arise from decreased neuronal proliferation or increased apoptosis at an early stage of embryonal development, but insight into the pathways involved is minimal. EIF2AK3 is involved in translation initiation. It has been proposed that loss of function mutations reduce the ability of the cell to respond to endoplasmic reticulum stress, resulting in apoptosis of pancreatic Langerhans cells. Our findings suggest that in some cases, early onset IDDM and SGP can arise from common mechanisms leading to increased apoptosis.

[Respiratory insufficiency caused by acute disseminated encephalomyelitis in a child]

A 1.5-year-old boy presented with progressive ataxia and meningeal irritation after a period of general malaise and fever. He was eventually admitted to a paediatric intensive care unit for respiratory insufficiency. A diagnosis of acute disseminated encephalomyelitis (ADEM) with pontine involvement was made. The patient was mechanically ventilated and treated with immunoglobulins and corticosteroids, after which he recovered almost completely. ADEM is characterised by rapidly progressive demyelination of the central nervous system. The exact incidence and aetiology are unknown. The disorder is considered to be an autoimmune reaction, and current treatment is aimed at the suppression of this reaction. Despite the dramatic clinical and radiological presentation of ADEM, the prognosis is favourable in most cases.

Brain abnormalities in a case of malonyl-CoA decarboxylase deficiency

Malonyl-CoA decarboxylase (MCD) deficiency is an extremely rare inborn error of metabolism that presents with metabolic acidosis, hypoglycemia, and/or cardiomyopathy. Patients also show neurological signs and symptoms that have been infrequently reported. We describe a girl with MCD deficiency, whose brain MRI shows white matter abnormalities and additionally diffuse pachygyria and periventricular heterotopia, consistent with a malformation of cortical development. MLYCD-gene sequence analysis shows normal genomic sequence but no messenger product, suggesting an abnormality of transcription regulation. Our patient has strikingly low appetite, which is interesting in the light of the proposed role of malonyl-CoA in the regulation of feeding control, but this remains to be confirmed in other patients. Considering the incomplete understanding of the role of metabolic pathways in brain development, patients with MCD deficiency should be evaluated with brain MRI and unexplained malformations of cortical development should be reason for metabolic screening.

Primitive neuroectodermal tumours (PNETs) located in the spinal canal; the relevance of classification as central or peripheral PNET

Intraspinal location of central PNET (cPNET) is very rare. We present a case, critically review all publications of primary intraspinal cPNET occurrence and discuss tendencies in clinical presentation. In several previous attempts to summarise, authors often confused cPNET with peripheral PNET (pPNET). cPNET and pPNET are different entities with different immunohistochemical profiles and genetic backgrounds. Clinically, they are both aggressive tumours, but exhibit different characteristics in their local manifestation and metastatic spread. Survival rates are quite similar provided that treatment is applied according to the established protocols. Protocols in cPNET treatment differ from those for pPNET as regards the order of the treatment sub-modalities, specific chemotherapeutic regimen and intensity, radiation dose and its extent and consequently, the side effects. Therefore, failure to distinguish cPNET from pPNET leads to clinical guidance and treatment proposals based on false assumptions, which might effect outcomes. Often, distinguishing between cPNET and pPNET is easy, because they occur in different location. In the case of intraspinal tumour location, however, the differentiation is crucial because both primary cPNET and pPNET can occur intraspinally, even though this is rare. Nowadays, demonstrating the expression of MIC2 glycoprotein by immunocytochemical staining (CD99) showing the specific EWS-FLI1 chimeric gene presence in pPNET, offers an easy way of making a differential diagnosis between cPNET and pPNET.

Novel mutations in three families confirm a major role of COL4A1 in hereditary porencephaly

BACKGROUND

Porencephaly (cystic cavities of the brain) is caused by perinatal vascular accidents from various causes. Several familial cases have been described and autosomal dominant inheritance linked to chromosome 13q has been suggested. COL4A1 is an essential component in basal membrane stability. Mouse mutants bearing an in-frame deletion of exon 40 of Col4a1 either die from haemorrhage in the perinatal period or have porencephaly in survivors. A report of inherited mutations in COL4A1 in two families has shown that familial porencephaly may have the same cause in humans.

OBJECTIVE

To describe three novel COL4A1 mutations.

RESULTS

The three mutations occurred in three unrelated Dutch families. There were two missense mutations of glycine residues predicted to result in abnormal collagen IV assembly, and one mutation predicted to abolish the traditional COL4A1 start codon. The last mutation was also present in an asymptomatic obligate carrier with white matter abnormalities on brain magnetic resonance imaging.

CONCLUSIONS

This observation confirms COL4A1 as a major locus for genetic predisposition to perinatal cerebral haemorrhage and porencephaly and suggests variable expression of COL4A1 mutations.

Progressive damage on high resolution computed tomography despite stable lung function in cystic fibrosis

For effective clinical management of cystic fibrosis (CF) lung disease it is important to closely monitor the start and progression of lung damage. The aim of this study was to investigate the ability of high-resolution computed tomography (HRCT) scoring systems and pulmonary function tests (PFT) to detect changes in lung disease. CF children (n=48) had two HRCT scans in combination with two PFT 2 yrs apart. Their scans were scored using five scoring systems (Castile, Brody, Helbich, Santamaria and Bhalla). "Sensitivity" was defined as the ability to detect disease progression. In this group of children, HRCT scores worsened. PFT remained unchanged or improved. Of the HRCT parameters, mucous plugging and the severity, extent and peripheral extension of bronchiectasis worsened significantly. Relationships between changes in HRCT scores and PFT were weak. Substantial structural lung damage was evident in some children who had normal lung function. These data show that high-resolution computed tomography is more sensitive than pulmonary function tests in the detection of early and progressive lung disease, and suggest that high-resolution computed tomography may be useful in the follow up of cystic fibrosis children and as an outcome measure in studies that aim to reduce lung damage.

Digital radiogrammetry of the hand in a pediatric and adolescent Dutch Caucasian population: normative data and measurements in children with inflammatory bowel disease and juvenile chronic arthritis

We have evaluated the applicability of a new Digital X-ray Radiogrammetry (DXR) system in a Dutch Caucasian pediatric population. For this study we enrolled 535 healthy participants who all signed an informed consent form. In addition, 20 children suffering from inflammatory bowel disease (IBD) and juvenile chronic arthritis (JCA) were enrolled. Radiographs of the left hand were obtained from all participants. From the healthy population a subset of children with a history of forearm fractures were separately analyzed. Measurements consisted of DXR (X-posure; Pronosco-Sectra, Linköping, Sweden). Five hundred thirty-five subjects were enrolled in the study. Twenty-two subjects (4.3%) were discontinued (age 3-10 years), all because of a nonrecognizable radiograph by the DXR system. The short-term coefficient of variation of DXR in this population was 0.59%. Significant differences in DXR-BMD between boys and girls for the ages of 11, 12, 16, 17, and 18 years were found. There were also significant differences in DXR-BMD between the sequential Tanner stages. For 88 subjects repeat radiographs were available (mean interval 1.8 years). In all cases an increase in DXR-BMD was seen. Girls with IBD, JCA, or a history of forearm fractures and boys with IBD showed a significantly lower DXR-BMD compared with healthy controls. We show that DXR is an applicable technique in children. Also, in a small subpopulation it is possible to discriminate children with a high risk of low BMD.

Slide tracheoplasty for congenital tracheal stenosis

BACKGROUND/PURPOSE

The aim of this study was to add to the experience of slide tracheoplasty in infants with congenital tracheal stenosis (CTS), to review the recent literature on this subject, and to evaluate the diagnostic workup in infants with CTS.

METHODS

A retrospective review of 3 infants with CTS treated with slide tracheoplasty was conducted at our institution. They all underwent bronchoscopy, tracheobronchography, and echocardiography. Therapy consisted of slide tracheoplasty and simultaneous correction of associated vascular malformations.

RESULTS

A pulmonary artery sling was missed initially on esophagography in 2 patients. Stridor became worse in 2 patients after tracheobronchography. After surgical therapy, 2 patients survived and were discharged 12 days after surgery. Both are without symptoms at follow-up of 12 and 20 months. One patient had inoperable restenosis and died 27 days after the operation.

CONCLUSIONS

Esophagography is not a reliable tool to depict associated vascular anomalies for patients with CTS. According to the literature, computer tomography has become more reliable to depict the tracheobronchial tree and is useful to elucidate associated vascular anomalies as well. Compared with other surgical techniques for infants with CTS reported in the literature, slide tracheoplasty has fewer postoperative complications and comparable survival rates.

Hereditary porencephaly: clinical and MRI findings in two Dutch families

Familial porencephaly is a rare disorder causing motor impairment, hemiplegia, mental retardation and epilepsy in variable degrees. Two families with porencephaly and apparently dominant inheritance are reported. Brain MRI findings are reviewed and described in seven affected individuals. Most patients also show white matter abnormalities in the cerebral hemisphere, also contralateral to the cystic lesion. In the first family an obligate carrier was identified who did not have a cystic lesion but clear abnormalities of the white matter. Although a predisposition for thrombophilia has previously been reported, we did not observe any genetic, environmental or epigenetic predisposition for the porencephaly. The lesions are most compatible with a deep venous thrombosis/ischemic event occurring in a late stage of pregnancy, not necessarily aggravated by perinatal asphyxia.

Arterial infarction caused by carotid artery dissection in the neonate

Arterial stroke in a neonate caused by carotid artery dissection is rare. We report two cases, one with dissection at the level of the skull base, one just distal to the carotid bulb. Non-invasive techniques like MR angiography and sonography demonstrated the dissection accurately. MR imaging, especially the diffusion-weighted images, showed the extension and site of the cerebral infarction. In one case dissection could be suspected following vacuum and forceps extraction. In the other no obvious birth trauma was reported. In conclusion, in a neonate with clinical signs suggestive of cerebral infarction, dissection of the carotid artery should be considered.

Estimation of lung growth using computed tomography

Anatomical studies suggest that normal lungs grow by rapid alveolar addition until about 2 yrs of age followed by a gradual increase in alveolar dimensions. The aim of this study was to examine the hypothesis that normal lung growth can be monitored by computed tomography (CT). Therefore, the gas volume per gram of lung tissue was estimated from measurements of lung density obtained from CT scans performed on children throughout the growth period. CT scans were performed on 17 males and 18 females, ranging in age from 15 days-17.6 yrs. CT-measured lung weight was correlated with predicted post mortem values and CT measured gas volume with predicted values of functional residual capacity. The median value for lung expansion was 1.86 mL x g(-1) at 15 days, decreased to 0.79 mL x g(-1) by 2 yrs and then increased steadily to 5.07 mL x g(-1) at 17 yrs. Computed tomography scans can be used to estimate lung weight, gas volume and expansion of normal lungs during the growth period. The increase in the lung expansion after the age of 2 yrs suggests progressive alveolar expansion with increasing lung volume.

Collagen Ialpha1 polymorphism is associated with bone characteristics in Caucasian children and young adults

A large proportion of the variation in bone mass can be explained by genetic factors. We analyzed the G to T substitution in the Sp1 binding site in the first intron of the collagen type Ialpha1 (COLIA1) gene in relation to bone mass. The genotypes GG, GT, and TT were determined in 148 Caucasian children and young adults. We performed dual energy X-ray absorptiometry twice (mean follow-up time 4.4 years), and speed of sound (SOS) was assessed by tibial ultrasonometry at follow-up. Genotype distribution was 104 (70%) GG, 40 (27%) GT and 4 (3%) TT. Carriers of the T-allele had a 0.5 SDS (standard deviation score) decreased bone mineral content (BMC) of total body (P = 0.001), and a 0.4 SDS decreased bone mineral density (BMD) for both lumbar spine (P = 0.04) and total body (P = 0.05). The genotype effect on BMD and BMC decreased after adjustment for height or body mass index. When we calculated apparent BMD, these differences diminished to 0.1 SDS and were no longer significant. T-allele carriers had shorter stature (0.4 SDS; P = 0.04) and smaller bones (0.5 SDS lower width of the lumbar vertebral body; P = 0.01). The T-allele was also associated with lower SOS (P = 0.03), independent of BMD and BMC, and lower lean body mass. Similar associations were found at follow-up. The change in BMD and BMC SDS between the first and second measurement did not differ between the GG and GT&TT group. In conclusion, the COLIA1 polymorphism in children and young adults is associated with several bone characteristics. However, at least a part of the COLIA1 effect on bone mass may be related to differences in frame size.

Spinal epidural abscess presenting with abdominal pain

We report a case of spinal epidural abscess presenting as abdominal pain. An 7-year-old boy presented with abdominal pain. He was operated on under suspicion of appendicitis. During operation, no abnormalities were found. Postoperatively, the abdominal pain did not subside. Subsequently, the boy developed neurological abnormalities. MRI showed a spinal epidural abscess. A laminectomy was performed and the boy was treated with antibiotics; he recovered well. This case showed that it is important to consider a spinal epidural abscess as a cause of abdominal pain with fever in children.

Bone mineral assessment with tibial ultrasonometry and dual-energy X-ray absorptiometry in long-term survivors of acute lymphoblastic leukemia in childhood

Acute lymphoblastic leukemia (ALL) in childhood is a serious disease that can affect growth and the attainment of maximal peak bone mass. The latter has recently been recognized as a risk factor for the development of osteoporosis later in life. To determine long-term effects of the disease itself and its treatment, we assessed the bone status of a group of long-term survivors of childhood ALL, all treated with high doses of steroids (dexamethasone) and methotrexate and without cranial irradiation. All 21 subjects enrolled in this cross-sectional study were diagnosed to have non-high-risk precursors acute lymphoblastic leukemia (12 boys and 9 girls, mean age 16.5 yr, range 12.2-25.4 yr). Standard deviation (SD) scores were calculated using a tibial ultrasound device and spinal dual-energy X-ray absorptiometry (DXA) device as bone assessment techniques. SD scores of those two different bone assessment techniques were compared. The mean SOS (speed of sound) SD scores (SDS) of the tibia (mean 0.26, standard deviation [sd] 1.00) were not significantly different from our reference value of 0. There was no significant difference between the SOS SDS in boys and girls. With DXA, no significant difference was seen between the mean BMD SDS and the reference data and no significant difference in BMD between boys and girls was found. The individual mean SDS for bone mineral density (BMD) of lumbar spine are 0.24 (sd 1.02), total body 0.17 (sd 1.00), and apparent BMD (BMAD) 0.07 (sd 1.09). Spearman's correlation between mean SOS SDS and mean BMD of lumbar spine was 0.47, mean SOS SDS and mean BMAD SDS was 0.43, and mean SOS SDS and mean BMD of total body was 0.49. These correlations were significant at the 0.05 level (two tailed). Despite high-dose dexamethasone and methotrexate used for treatment of these children with ALL, no long-term side effects on the bone mineral status of the subjects, measured with DXA or tibial ultrasonometry, could be determined.

Is the Greulich and Pyle atlas still valid for Dutch Caucasian children today?

BACKGROUND

In our Paediatric Radiology Department, the Greulich and Pyle technique is used to assess skeletal age. Several authors have raised questions with regard to the applicability of this technique in a contemporary paediatric and adolescent population.

OBJECTIVE

To compare skeletal age and calendar age in a healthy Dutch Caucasian population in order to test the applicability in this specific population.

MATERIALS AND METHODS

For this study we enrolled 278 Dutch Caucasian boys (age range 5.0-19.5 years, mean 12.6 years) and 294 Dutch Caucasian girls (age range 5.2-19.9 years, mean 12.2 years). Radiographs of the left hand were scored according to the Greulich and Pyle atlas by two investigators.

RESULTS

Intra-observer coefficient of variation of duplicate assessment of skeletal age for investigator 1 (resident) was 2.4 % and for investigator 2 (radiologist) was 1.5 %. We found no significant systematic differences between the two observers regarding variability and levels of measurement, and the agreement was good. There was a strongly significant correlation between skeletal and calendar age rgirls = 0.974 and rboys = 0.979 (P < 0.001). On average, calendar age preceded skeletal age by a small amount (1.7 months in girls and 3.3 months in boys, both P < 0.001).

CONCLUSIONS

The reliability of the Greulich and Pyle atlas in our study corresponds well with previously reported studies. Based on our data, we conclude that the Greulich and Pyle atlas is still applicable in Dutch Caucasian children and adolescents.

Quantitative tibial ultrasonometry versus radiographic phalangeal absorptiometry in a Caucasian pediatric population

There is a need for a reliable bone assessment technique in children. In this study, we compare an existing technique used in children, radiographic absorptiometry (RA), with a relatively novel technique, quantitative tibial ultrasonometry (QUS). In a prospective cohort study, we enrolled 290 girls (mean age 12.7 years) and 273 boys (mean age 12.4 years). Radiographs of the left hand and the left index finger were taken with an aluminium reference wedge within the field of exposure. Radiographic absorptiometry on the second middle phalanx at the mid-level (BMD50%) and proximal quarter (BMD25%) was performed with interactive software. Tibial QUS was performed using the SoundScan Compact. Multiple regression analysis showed that SOS correlated significantly with BMD25% for both boys (r = 0.65, P < 0.001) and girls (r = 0.59, P < 0.001), taking into account age and gender. The same applied for the correlation between speed of sound (SOS) and BMD50% in boys (r = 0.62, P < 0.001) and girls (r = 0.67, P < 0.001). Cubic regression between calendar age and BMD25% showed the best fit for both boys (r2 = 0.60) and girls (r2 = 0.60). For BMD50% a difference in regression was found between boys and girls. Quadratic regression gave a satisfactory fit for boys (r2 = 0.61 ) whereas for girls, a cubic relation was best (r2 = 0.59). Overall, there was a significant correlation between BMD25% and BMD50% for boys r = 0.89 and for girls r = 0.91 (both P < 0.001). Our data show a significant correlation between two different bone assessment techniques. In addition, these data suggest that both tibial ultrasonometry and RA are useful techniques in children.

Comparison between quantitative calcaneal and tibial ultrasound in a Dutch Caucasian pediatric and adolescent population

In the field of bone densitometry, attention has recently been focused on the pediatric population. Quantitative ultrasound (QUS) as bone assessment technique has many advantages for children in comparison with bone assessment techniques that use ionizing radiation. In this pilot study, we investigated the use of calcaneal and tibial QUS systems in a healthy Caucasian pediatric population. We studied 120 healthy Caucasian Dutch children between ages 7 and 19 yr: 53 boys (mean age of 12.5 yr, range 4.5-18) and 67 girls (mean age of 13.5 yr; range 7.1-19). We recruited children from a large population who previously had participated in a bone assessment study performed at our hospital. Two operators performed calcaneal QUS of the right calcaneus and tibial QUS of the right tibia. The correlation between calcaneal and tibial ultrasound was modest but significant (r = 0.29; p < 0.01). Using the calcaneal device, we found in girls a weak positive correlation between skeletal age and speed of sound (SOS) (r = 0.38), broadband ultrasound attenuation (r = 0.57), and quantitative ultrasound index (r = 0.46), all with a value of p < 0.01. For boys all parameters failed to reach significance. Using the tibial device, we found a good correlation between skeletal age and SOS in girls (r = 0.76) and modest correlation in boys (r = 0.50), both with a value of p < 0.01. This is one of the first studies to present a comparison between two ultrasound techniques in children. At present we feel that, in light of the poor correlation with skeletal age, calcaneal ultrasound has yet to prove its efficacy in children. Tibial ultrasound seems to be a good bone assessment technique in children.

Absence of a PDX-1 mutation and normal gastroduodenal immunohistology in a child with pancreatic agenesis

Pancreatic agenesis is a rare condition, of which only a limited number of cases have been described. One recent paper reported a homozygous mutation in the pancreatic duodenal homeobox gene 1 (PDX-1) in a child with pancreatic agenesis. We report a 6-year-old boy with pancreatic agenesis, treated medically, without abnormalities in the PDX-1 gene coding sequence and with normal gastroduodenal endocrine cell distribution. Genes other than PDX-1 also appear to be involved in human pancreatic agenesis.

Tibial quantitative ultrasound versus whole-body and lumbar spine DXA in a Dutch pediatric and adolescent population

RATIONALE AND OBJECTIVES

To understand normal bone development, studies in healthy children and adolescents are important. To assess the applicability of tibial quantitative ultrasound measurements (QUS) in children, we performed a study that compared dual-energy x-ray absorptiometry (DXA) of the lumbar spine and whole body with tibial QUS.

METHODS

For this study we recruited 146 Dutch children and adolescents, 58 boys (median age, 14.1 years; range, 7.6-23.4 years) and 88 girls (median age, 18.0 years; range, 7.6-23.5 years). Tanner stage, weight, and height were assessed for all participants. Bone mineral density (BMD; g x cm(-2)) of the whole body and lumbar spine (L2-L4) and bone mineral apparent density (BMAD) of the lumbar spine (g x cm(-3)) were assessed by using the Lunar DPXL. For tibial QUS, the Soundscan compact system was used.

RESULTS

Both lumbar as well as whole-body BMD showed a strong, significant correlation with tibial QUS in boys and girls: rtotal body boys = 0.81, rtotal body girls = 0.77, rlumbar spine boys = 0.79, and rlumbar spine girls = 0.72. Lumbar spine BMAD also showed significant correlations with tibial QUS: rboys= 0.63 and rgirls = 0.63 (for all correlations, P < 0.001).

CONCLUSIONS

Our study showing strong, significant correlations between DXA and tibial QUS measurements suggests that tibial QUS is a technique that may be applicable in children and adolescents.

Optimal rotational interval for 3-dimensional echocardiography data acquisition for rapid and accurate measurement of left ventricular function

BACKGROUND

Prolonged 3-dimensional echocardiography (3DE) acquisition time currently limits its routine use for calculating left ventricular volume (LVV) and ejection fraction (EF). Our goal was to reduce the acquisition time by defining the largest rotational acquisition interval that still allows 3DE reconstruction for accurate and reproducible LVV and EF calculation.

METHODS

Twenty-one subjects underwent magnetic resonance imaging and precordial 3DE with 2 degrees acquisition intervals. Images were processed to result in data sets containing images at 2 degrees, 4 degrees, 8 degrees, 16 degrees, 32 degrees, and 64 degrees intervals by excluding images in between. With use of the paraplane feature, 8 equidistant short-axis slices were generated from each data set. The suitability of these short-axis slices for manual endocardial tracing was scored visually by 4 independent experienced observers. The LVV and EF were calculated by using Simpson's rule from 3DE data sets with 2 degrees, 8 degrees, and 16 degrees intervals, and the results were compared with values obtained from magnetic resonance imaging. The probability of 3DE to detect LVV and EF differences was calculated.

RESULTS

All patients were in sinus rhythm with a mean heart rate of 72 bpm (SD + or - 12). The LV short-axis images obtained with 16 degrees rotational scanning intervals allowed LV endocardial tracing in all subjects. Good correlation, close limits of agreement, and nonsignificant differences were found between values of LVV and EF calculated with 3DE at 2 degrees, 8 degrees, and 16 degrees rotational intervals and those obtained with magnetic resonance imaging. At steps of 16 degrees, 3DE had excellent correlation (r = 98, 99, and 99), close limits of agreement (+ or - 38, + or - 28.6, and + or - 4.8), and nonsignificant differences (P =.5,.8, and.2) with values obtained from magnetic resonance imaging for calculating end-diastolic LVV, end-systolic LVV, and EF, respectively. Three-dimensional echocardiography with use of 16 degrees rotational intervals could detect 15-mL differences in end-diastolic volume with a probability of 95%, 11-mL differences in end-systolic volume with a probability of 92%, and 0.02 differences in EF with a probability of 95%.

CONCLUSIONS

The 3DE data sets reconstructed with images selected at 16 degrees intervals from data sets obtained at 2 degrees precordial rotational acquisition intervals allowed the generation of LV short-axis images with adequate quality for endocardial border tracing. Therefore precordial acquisition at 16 degrees intervals would be sufficient for the reconstruction of 3DE data sets for LV function measurement. This would reduce the acquisition time while maintaining enough accuracy for clinical decision making and would thus make 3DE more practical as a routine method.