Brain Ultrasonography Consensus on Skill Recommendations and Competence Levels Within the Critical Care Setting.

BACKGROUND: To report a consensus on the different competency levels for the elaboration of skill recommendations in performing brain ultrasonography within the neurocritical care setting. METHODS: Four brain ultrasound experts, supported by a methodologist, performed a preselection of indicators and skills based on the current literature and clinical expertise. An international panel of experts was recruited and subjected to web-based questionnaires according to a Delphi method presented in three separate rounds. A pre-defined threshold of agreement was established on expert subjective opinions, > 84% of votes was set to support a strong recommendation and > 68% for a weak recommendation. Below these thresholds, no recommendation reached. RESULTS: We defined four different skill levels (basic, basic-plus, pre-advanced, advanced). Twenty-five experts participated to the full process. After four rounds of questions, two items received a strong recommendation in the basic skill category, three in the advanced, twelve in the basic-plus, and seven in the pre-advanced. Two items in the pre-advanced category received a weak recommendation and three could not be collocated and were excluded from the list. CONCLUSIONS: Results from this consensus permitted stratification of the different ultrasound examination skills in four levels with progressively increasing competences. This consensus can be useful as a guide for beginners in brain ultrasonography and for the development of specific training programs within this field.

Nomograms for Fetal Cardiac Ventricular Width and Right-to-Left Ventricular Ratio.

OBJECTIVES: To establish nomograms for right ventricular (RV) and left ventricular (LV) widths and their ratio from 16 to 38 gestational weeks. METHODS: We conducted a retrospective evaluation of 1242 fetal echocardiographic examinations with normal findings in a single referral medical center between 2007 and 2013. We excluded all echocardiographic examinations with abnormal findings. The RV and LV widths, measured in end diastole from inner to inner line below the valves' insertion at the 4-chamber view, were obtained. Nomograms for the RV and LV widths and RV/LV ratio from 16 to 38 gestational weeks were constructed by using separate best-fitted regression models for estimation of mean and standard deviation at each gestational age (GA). RESULTS: Regression models for the RV and LV widths and RV/LV ratio were best fit by different-degree polynomial regression. The mean RV and LV widths and RV/LV ratio (±2 SD) increased statistically with GA from 16 to 38 weeks: 4.13 (3.00-5.44) to 16.68 (12.98-20.83) mm, 4.21 (3.18-5.49) to 15.17 (11.60-19.56) mm, and 1.03 (0.87-1.23) to 1.06 (0.87-1.30), respectively. Although the width increments in the RV and LV were both statistically and clinically significant, the ratio increment seemed to fall into the error of measurement and thus has no clinical significance. CONCLUSIONS: Reference values for cardiac ventricle widths and their ratio throughout gestation were established. The RV/LV ratio increases with GA, although without clinical significance. These reference values will be useful in objective assessment of RV-to-LV disproportion.

The reliability of fetal MRI in the assessment of brain malformations.

OBJECTIVES: To assess the inter- and intraobserver reliability of different fetal MRI measurements in cases of fetal brain malformations and to examine the concordance between ultrasonography (US) and MRI findings. METHODS: Fetal brain MRIs and US findings of 56 pregnant women were retrieved from the institutional database. Standardized fetal brain MRI measurements were performed by 4 observers, and the inter- and intraobserver reliability was determined. Additionally, US and MRI findings were retrospectively compared. RESULTS: The interobserver intraclass correlation coefficient (ICC) was above 0.9 for the cerebellum and posterior horn of the lateral ventricle. The measurements regarding the third ventricle (0.50), the fourth ventricle (0.58), and the corpus callosum (0.63) showed poor reliability. Overall, the intraobserver reliability was greater than the interobserver reliability. US and MRI findings were discordant in 29% of the cases with MRI rendering an extended diagnosis in 18%, a change of diagnosis in 3.6%, and excluding pathological findings suspected on US in 7.1%. CONCLUSIONS: Fetal MRI is a valuable complement to US in the investigation of fetal brain malformations. The reliability of most parameters was high, except for the measurements of the third and fourth ventricles and the corpus callosum.

Assessment of brain midline shift using sonography in neurosurgical ICU patients.

INTRODUCTION: Brain midline shift (MLS) is a life-threatening condition that requires urgent diagnosis and treatment. We aimed to validate bedside assessment of MLS with Transcranial Sonography (TCS) in neurosurgical ICU patients by comparing it to CT. METHODS: In this prospective single centre study, patients who underwent a head CT were included and a concomitant TCS performed. TCS MLS was determined by measuring the difference between the distance from skull to the third ventricle on both sides, using a 2 to 4 MHz probe through the temporal window. CT MLS was measured as the difference between the ideal midline and the septum pellucidum. A significant MLS was defined on head CT as > 0.5 cm. RESULTS: A total of 52 neurosurgical ICU patients were included. The MLS (mean ± SD) was 0.32 ± 0.36 cm using TCS and 0.47 ± 0.67 cm using CT. The Pearson's correlation coefficient (r(2)) between TCS and CT scan was 0.65 (P < 0.001). The bias was 0.09 cm and the limits of agreements were 1.10 and -0.92 cm. The area under the ROC curve for detecting a significant MLS with TCS was 0.86 (95% CI = 0.74 to 0.94), and, using 0.35 cm as a cut-off, the sensitivity was 84.2%, the specificity 84.8% and the positive likelihood ratio was 5.56. CONCLUSIONS: This study suggests that TCS could detect MLS with reasonable accuracy in neurosurgical ICU patients and that it could serve as a bedside tool to facilitate early diagnosis and treatment for patients with a significant intracranial mass effect.

Transcranial sonography (TCS) of brain parenchyma in movement disorders: quality standards, diagnostic applications and novel technologies.

Transcranial B-mode sonography (TCS) of brain parenchyma is being increasingly used as a diagnostic tool in movement disorders. Compared to other neuroimaging modalities such as magnetic resonance imaging (MRI) and computed tomography, TCS can be performed today with portable machines and has the advantages of noninvasiveness and high resistance to movement artifacts. In distinct brain disorders TCS detects abnormalities that cannot be visualized or can only be visualized with significant effort with other imaging methods. In the field of movement disorders, TCS has been established mainly as a tool for the early and differential diagnosis of Parkinson's disease. The postoperative position control of deep brain stimulation electrodes, especially in the subthalamic nucleus, can reliably and safely be performed with TCS.  The present update review summarizes the current methodological standards and defines quality criteria of adequate TCS imaging and assessment of diagnostically relevant deep brain structures such as substantia nigra, brainstem raphe, basal ganglia and ventricles. Finally, an overview is given on recent technological advances including TCS-MRI fusion imaging and upcoming technologies of digitized image analysis aiming at a more investigator-independent assessment of deep brain structures on TCS.

Reader variability in the use of diagnostic terms to describe white matter lesions seen on cranial scans of severely premature infants: the ELGAN study.

PURPOSE: To evaluate reader variability of white matter lesions seen on cranial sonographic scans of extreme low gestational age neonates (ELGANs). METHODS: In 1,452 ELGANs, cranial sonographic scans were obtained in the first and second postnatal weeks, and between the third postnatal week and term. All sets of scans were read independently by two sonologists. We reviewed the use of four diagnostic labels: early periventricular leucomalacia, cystic periventricular leucomalacia, periventricular hemorrhagic infarction (PVHI), and other white matter diagnosis, by 16 sonologists at 14 institutions. We evaluated the association of these labels with location and laterality of hyperechoic and hypoechoic lesions, location of intraventricular hemorrhage, and characteristics of ventricular enlargement. RESULTS: Experienced sonologists differed substantially in their application of the diagnostic labels. Three readers applied early periventricular leucomalacia to more than one fourth of all the scans they read, whereas eight applied this label to ≤5% of scans. Five applied PVHI to ≥10% of scans, while three applied this label to ≤5% of scans. More than one third of scans labeled cystic periventricular leucomalacia had unilateral hypoechoic lesions. White matter abnormalities in PVHI were more extensive than in periventricular leucomalacia and were more anteriorly located. Hypoechoic lesions on late scans tended to be in the same locations, regardless of the diagnostic label applied. CONCLUSIONS: Experienced sonologists differ considerably in their tendency to apply diagnostic labels for white matter lesions. This is due to lack of universally agreed-upon definitions. We recommend reducing this variability to improve the validity of large multicenter studies.

Adaptive focusing for transcranial ultrasound imaging using dual arrays.

Ultrasonic brain imaging remains difficult and limited because of the strong aberrating effects of the skull (absorption, diffusion and refraction of ultrasounds): high resolution transcranial imaging would require adaptive focusing techniques in order to correct the defocusing effect of the skull. In this paper, a noninvasive brain imaging device is presented. It is made of two identical linear arrays of 128 transducers located on each side of the skull. It is possible to separate the respective influence of the two bone windows on the path of an ultrasonic wave propagating from one array to the other, and thus estimate at each frequency the attenuation and phase shift locally induced by each bone window. The information obtained on attenuation and phase is used to correct the wave fronts that have to be sent through the skull in order to obtain a good focusing inside the skull. Compared to uncorrected wave fronts, the spatial shift of the focal spot is corrected, the width of the focal spot is reduced, and the sidelobes level is decreased up to 17 dB. Transcranial images of a phantom are presented and exhibit the improvement in image quality provided by this new noninvasive adaptive focusing method.

Variable interpretation of ultrasonograms may contribute to variation in the reported incidence of white matter damage between newborn intensive care units in New Zealand.

BACKGROUND: The incidence of cerebral white matter damage reported to the Australian and New Zealand Neonatal Network (ANZNN) varies between neonatal intensive care units (NICUs). HYPOTHESIS: Differences in the capture, storage, and interpretation of the cerebral ultrasound scans could account for some of this variation. METHODS: A total of 255 infants of birth weight <1500 g and gestation <32 weeks born between 1997 and 2002 and drawn equally from each of the six NICUs in New Zealand were randomly selected from the ANZNN database. Half had early cerebral ultrasound scans previously reported to ANZNN as normal, and half had scans reported as abnormal. The original scans were copied, anonymised, and independently read by a panel of three experts using a standardised method of reviewing and reporting. RESULTS: There was considerable variation between NICUs in methods of image capture, quality, and completeness of the scans. There was only moderate agreement between the reviewers' reports and the original reports to the ANZNN (kappa 0.45-0.51) and between the reviewers (kappa 0.54-0.64). The reviewers reported three to six times more white matter damage than had been reported to the ANZNN. CONCLUSION: Some of the reported variation in white matter damage between NICUs may be due to differences in capture and interpretation of cerebral ultrasound scans.

Intra-operative 3D ultrasound in neurosurgery.

In recent years there has been a considerable improvement in the quality of ultrasound (US) imaging. The integration of 3D US with neuronavigation technology has created an efficient and inexpensive tool for intra-operative imaging in neurosurgery. In this review we present the technological background and an overview of the wide range of different applications. The technology has so far mostly been applied to improve surgery of tumours in brain tissue, but it has also been found to be useful in other procedures such as operations for cavernous haemangiomas, skull base tumours, syringomyelia, medulla tumours, aneurysms, AVMs and endoscopy guidance.

Does variation in interpretation of ultrasonograms account for the variation in incidence of germinal matrix/intraventricular haemorrhage between newborn intensive care units in New Zealand?

BACKGROUND: The incidence of germinal matrix/intraventricular haemorrhage (GM/IVH) reported to the Australian and New Zealand Neonatal Network (ANZNN) varies between neonatal intensive care units (NICUs). HYPOTHESIS: Differences in the capture, storage, and interpretation of the cerebral ultrasound scans may account for some of this variation. METHODS: A total of 255 infants with birth weight <1500 g and gestation <32 weeks born between 1997 and 2002 were randomly selected from the ANZNN database, 44 from each of the six NICUs in New Zealand. Twenty two infants from each NICU had cerebral ultrasound scans previously reported to ANZNN as normal; another 22 had scans reported as abnormal. The original scans were copied using digital photography and anonymised and independently read by a panel of three experts using a standardised method of reviewing and reporting. RESULTS: There was considerable variation between NICUs in methods of image capture and quality and completeness of the scans. However, there was little variation in the reporting of scans between the reviewers and the reports to ANZNN (weighted kappa 0.75-0.91). Grade 1 GM/IVH was generally over-reported and grade 4 under-reported to the ANZNN. CONCLUSION: For all NICUs, a high level of agreement was found between the reviewers' reports and the reports to the ANZNN. Thus the variation between NICUs in the incidence of GM/IVH reported to the ANZNN is unlikely to be due to differences in capture, storage, and interpretation of the cerebral ultrasound scans. Further investigation is warranted into the reasons for the variation in incidence of GM/IVH between NICUs.

Gender comparisons of diagnostic evaluation for ischemic stroke patients.

BACKGROUND: Sixty-two percent of all stroke deaths in the United States occur in women. We compared diagnostic evaluations by gender in ischemic stroke patients in a biethnic, population-based study. METHODS: A random sample of patients with ischemic stroke identified between 2000 and 2002 by BASIC (Brain Attack Surveillance in Corpus Christi Project) were selected for this study (n = 381). Gender differences in the use of stroke diagnostic tests were assessed. Separate multivariable logistic regression models predicting diagnostic test use were constructed, adjusted for age, ethnicity, hypertension, atrial fibrillation, diabetes, history of stroke, coronary artery disease, having a primary care provider, discharge disposition, modified Rankin Scale score at discharge, and insurance status. RESULTS: The study population consisted of 161 men and 220 women. Median age was 74.3 years. The respective proportions of males and females receiving any carotid artery evaluation were 71% and 62%; brain MRI, 43% and 41%; echocardiography, 57% and 48%; and EKG, 90% and 86%. Multivariable logistic models found that women were less likely to undergo echocardiography (odds ratio [OR] 0.64, CI: 0.42 to 0.98) and carotid evaluation (OR 0.57, CI: 0.36 to 0.91). There was no association of ischemic stroke subtype and gender to explain these results (p = 0.76). CONCLUSIONS: Despite controlling for explanatory variables, women with stroke were less likely to receive standard diagnostic tests vs men. Intervention is needed to increase access to quality stroke care for women.

Evaluation and development of potentially better practices for the prevention of brain hemorrhage and ischemic brain injury in very low birth weight infants.

OBJECTIVE: Neonatal care providers from 5 institutions formed a multidisciplinary focus group with the purpose of identifying potentially better practices, the implementation of which would lead to a reduction in the incidence of intracranial hemorrhage and periventricular leukomalacia in very low birth weight infants. METHODS: Practices were analyzed, 4 benchmark neonatal intensive care units were identified and evaluated, and the literature was assessed using an evidence-based approach. The work was also reviewed by a nationally respected expert. RESULTS: Ten potentially better clinical practices were identified. In addition, variability in cranial ultrasound practice, related to both procedural process and interpretation, was identified as a confounding problem in evaluating quality. Using the same process, potentially better cranial ultrasound practices were also identified. CONCLUSIONS: Implementation of these practices will improve clinical outcomes as well as the reliability of sonogram interpretation, the basis for evaluating the quality of the team's work.

Correlation of ultrasound with postmortem neuropathologic studies in neonates.

We examined the correlation between cranial sonogram and postmortem examination neurodiagnoses in 51 infants (30 boys and 21 girls) who underwent cranial sonogram before death. The mean gestation of the infants at birth was 32 weeks 6 days; the mean birth weight, 1,992 gm; and the mean survival, 27 days. Most infants had several postmortem examination neurodiagnoses; therefore the postmortem examination diagnosis considered to be most significant in terms of clinical management and long-term neurologic function was chosen for each infant and designated as the primary diagnosis. The ability of the cranial sonogram to diagnose the primary diagnosis was then evaluated. The accuracy of the cranial sonogram in defining primary diagnoses was 59%. There were 21 cases (41%) in which cranial sonogram failed to define the primary diagnosis; nine of these could be explained on the basis of the timing of the ultrasound in relation to the age of the lesion or to the microscopic nature of the lesion. In 12 patients the factors causing the failure of cranial sonogram to define primary postmortem examination diagnoses could not be identified. The positive predictive value of a cranial sonogram diagnosis was 77%; the negative predictive value was 19%.

Correlation between neonatal cranial ultrasound, MRI in infancy and neurodevelopmental outcome in infants with a large intraventricular haemorrhage with or without unilateral parenchymal involvement.

UNLABELLED: During a 7-year-period, 1625 infants of 34 weeks gestation or less were enrolled in a prospective ultrasound (US) study. One hundred and eleven (6.8%) infants developed a large intraventricular haemorrhage (IVH) with or without unilateral parenchymal involvement (PI). Fifty-six of these 111 infants survived (50.4%) and in 23 (41%) of them a magnetic resonance imaging (MRI) study was performed beyond 12 months corrected age. There appeared to be a good agreement between neonatal ultrasound findings and MRI changes noted in infancy. Of the 10 cases with a large IVH without PI (group A), seven had a VP shunt with complete decompression of previously enlarged ventricles. Six of these seven infants had periventricular hyperintensity (PVHI) but none developed cerebral palsy (CP). Two of the ten cases without a VP shunt had irregular ventricular enlargement (VE) with PVHI in one. Both developed CP. Seven cases showed thinning of the corpus callosum. Of the 13 cases with a large IVH associated with PI (group B), the site of the PI could still be recognised on MRI and the degree of communication of the porencephalic cyst (PC) with the lateral ventricles correlated well with neonatal US findings. On MRI, VE was present in only 6 cases. Wallerian degeneration was present in 9/13 infants and all but one developed a hemiplegia. In 12/13 cases there was thinning of the corpus callosum, either focal or diffuse. PVHI was present in all infants. In 6/13 PVHI was only present around the PC. Neurodevelopmental outcome differed for both groups. CP was only present in 2/10 infants in group A, compared to 11/ 13 in group B. Global delay, in the absence of CP, was more common in infants with a large IVH than in those with associated PI. CONCLUSION: Combining neonatal US with MRI in infancy enhances our understanding of the long-term effects of severe haemorrhagic brain lesions, occurring in preterm infants.

Reliability of interpretation of cranial ultrasound examinations of very low-birthweight neonates.

The authors studied intra- and inter-reader reliability of the interpretation of cranial ultrasound examinations of very low-birthweight infants. A radiologist read 173 films, 88 of which he had read previously; the other 85 had been read previously by a second radiologist. For the diagnoses of subependymal hemorrhage and intraventricular hemorrhage, intra-reader agreement was similar to inter-reader agreement. 98 ultrasound films were read initially as showing subependymal hemorrhage; in nine cases the second reading did not agree. In five of 58 cases read initially as showing intraventricular hemorrhage, the second reading did not agree. Similarly, of 32 cases read initially as showing intraparenchymal echo-density, four were interpreted as negative on second reading. For all three diagnoses, disagreement occurred often enough to cause substantial misclassification bias when cranial ultrasound is used for clinical research.

Accuracy of echoventriculography as compared with computer tomography in children.

The accuracy of echoventriculography (echo-VG) using CT findings as a reference has been examined in 144 children. Lateral ventricular index on echo-VG was compared with anterior horn and body indices on CT. The correlation coefficient was 0.617 and 0.725, respectively. Twelve cases with a deviation exceeding 2 SD in the regression between the indices were analysed. The conclusion is that echo-VG is fairly accurate and useful as a screening method and for follow-up examinations in children.

[The advantages and limitations of an automatic ultrasound determination of the cerebral midline--a study of 1889 cases]. / Möglichkeiten und Grenzen einer automatisierten Mittellinienbestimmung bei der Ultraschalluntersuchung des Schädels--Eine Untersuchung von 1889 Fällen

The examination of the brain with ultrasound has become an indispensible diagnostic tool in all cases of intracranial pathology. Valuable information is obtained both in emergencies and in follow-up studies. Since long practice is necessary before the results of echoencephalograms can be interpreted accurately, a need was felt for a standardization of the examination which would eliminate the subjective influence of the investigator. The automatic midline computer, called Midliner, which has recently become available, makes fewer demands on the experience of the investigator although the diagnostic possibilities are not as broad. The position of the midline echo is of primary interest, although the width of the third ventricle can be successfully determined in occasional cases. this study, which presents the results of the Midliner examinations in three clinics, is grouped according to diagnosis. Through a comparison with conventional A-scan echoencephalograms, as well as with neuroradiological and operative findings in 1889 cases, the reliability of this method is clearly demonstrated. The advantages and disadvantages of the examination are discussed and the field of application indicated.