A prospective study on fetal posterior cranial fossa assessment for early detection of open spina bifida at 11-13 weeks.

The objective of this study was to test three measurements: brain stem (BS), intracranial translucency (IT) and brain stem to occipital bone distance (BSOB), as well as one landmark: cisterna magna (CM) visibility, for early diagnosis of open spina bifida (OSB) in a low risk population. A prospective observational study was undertaken in a university hospital. A sample of 1479 women consented to participate between 20 September 2013 and 30 June 2015. Measurements were performed from the mid-sagittal view, as is routinely used for nuchal thickness assessment. CM visibility was assessed qualitatively as the third anechoic band in the posterior cranial fossa (PCF). All pregnancies were screened with a combination of maternal serum alpha-fetoprotein and second trimester anomaly scan and followed until delivery. Predictive values were calculated for each marker. We were able to diagnose two OSB cases and highly suspect one Dandy-Walker malformation case at the first trimester scan by the observation of PCF. PCF characteristics of OSB cases were increased BS diameter, increased BS-BSOB ratio and non-visualization of the CM. All the markers demonstrated high sensitivity and specificity but CM visibility reached the highest positive predictive value. Due to relatively high false positive rates, PCF measurements could not reach a satisfactory performance to validate their clinical use as a single marker. CM visibility has the advantage of being a qualitative marker and reduces the need for sophisticated and time-consuming measurements. Intracranial translucency and BS-BSOB ratio measurements should be used when the CM visibility is absent or in doubt.

Percentile-based assessment of craniosynostosis.

Perioperative assessment of craniosynostosis is based mostly on subjective scores. In this study, we sought to find an objective method to assess cranial deformation based on normative craniofacial percentiles. Anthropometric datasets from 104 (79 males, 25 females) patients with craniosynostoses were included. Anthropometric data were compared with normative age-dependent percentiles. Deviations above the 90th or below the 10th percentile were defined as significant cranial deformation. The cohort comprised 69 children with sagittal, 22 metopic, nine coronal, two bicoronal, one lambdoid, and one with coronal + lambdoid craniosynostosis. Most children with sagittal synostosis were above the 90th percentile for cranial circumference and length, whereas only 27.9% were below the 10th percentile for cranial width. Most (83%) children with scaphocephaly had cranial indices below the 10th percentile. For trigonocephaly, we found normal cranial circumference values in most patients (10th-90th percentile), 40.9% were above the 90th percentile for cranial length, and 63.1% and 57.9% were above the 90th percentiles for sagittal and transverse circumferences. For unicoronal synostosis transverse circumference was above the 90th percentile in 83.3% of children. Matching of anthropometric data of craniosynostosis patients with craniofacial norms could be useful in grading the clinical picture and potentially adapting the operative procedure.

Quantitative and qualitative assessment of morphology in sagittal synostosis: mid-sagittal vector analysis.

Consensus remains lacking regarding the optimal surgical treatment modality for sagittal synostosis. There is, however, wide agreement that objective analytical methods are required to demonstrate the characteristic morphology of the condition and to substantiate the benefits of specified surgical techniques. Simple calculated anthropomorphic indices, such as the cranial index, are commonly used but fail to provide satisfactory representation of morphology, which is far more complex than can be represented by its simple length-width ratio. Techniques to provide more comprehensive, yet practical, assessment of morphology are needed for analytic purposes. Herein, we introduce vector analysis as an objective, computed tomography (CT)-based morphometric technique for assessment of cranial morphology; this work represents the first application of the technique mid-sagittal vector analysis (MSVA). MSVA is a single plane application that was devised to address dysmorphology in sagittal synostosis. It was our hypothesis that MSVA would quantitatively and qualitatively depict preoperative morphology and postoperative correction in specific regions. Sixteen patients undergoing cranial reshaping surgery for sagittal synostosis were included in the study. All patients underwent routine preoperative and 1 year postoperative CT scans, from which the MSVA was derived. MSVA is a radial vector analysis in which distances to the cranial surface are measured from a single reference point origin in the sagittal plane. Preoperative morphology, characterized by respective vectors, was analyzed in three regions: the frontal, vertex, and occipital regions. Comparison with postoperative paired data was conducted for each patient. The analysis of postoperative change demonstrated (1) decrease in prominence in the frontal and occipital regions, (2) increase in height and forward translation of the vertex, and (3) ability to distinguish and qualify frontal versus occipital bossing and correction thereof. We conclude that the longitudinal differences associated with scaphocephaly are well characterized and differentiated by MSVA. Quantitative and qualitative assessment identifies three relevant regions affected by the condition and its treatment: the frontal, vertex, and occipital regions. The transverse dimension is not addressed in this single plane analysis; a more comprehensive application will require additional planes of analysis and the development of a normative database.

MRI assessment of the alar ligaments in the late stage of whiplash injury--a study of structural abnormalities and observer agreement.

Our aim was to characterise and classify structural changes in the alar ligaments in the late stage of whiplash injuries by use of a new MRI protocol, and to evaluate the reliability and the validity of this classification. We studied 92 whiplash-injured and 30 uninjured individuals who underwent proton density-weighted MRI of the craniovertebral junction in three orthogonal planes. Changes in the alar ligaments (grades 0-3) based on the ratio between the high signal area and the total cross-sectional area were rated twice at a 4-month interval, independently by three radiologists. Inter- and intraobserver statistics were calculated by ordinary and weighted kappa. Cases classified differently were reviewed to identify potential causes for disagreement. The alar ligaments were satisfactorily demonstrated in all cases (244 ligaments in 122 individuals). The lesions, 2-9 years after the injury, varied from small high-signal spots to high signal throughout the cross-sectional area. Signal was highest near the condylar insertion in 82 of 94 ligaments, indicating a lesion near that insertion, and near the dental insertion in eight, indicating a medial lesion. No grade 2 or 3 lesion was found in the control group. At least two observers assigned the same grade to 214 ligaments (87.7%) on the second occasion. In 30 ligaments (12.3%) this agreement was not obtained. Pair-wise interobserver agreement (weighted kappa) was fair to moderate (0.31-0.54) in the first grading, improving to moderate (0.49-0.57) in the second. Intraobserver agreement (weighted kappa) was moderate to good (0.43-0.70). Whiplash trauma can cause permanent damage to the alar ligaments, which can be shown by high-resolution proton density-weighted MRI. Reliability of classification of alar ligament lesions needs to be improved.

Occipital lesions: a possible cost of cradleboards.

This examination of a Mimbres-Mogollon pueblo skeletal sample reveals a surprising percentage of individuals with occipital lesions. Each lesion is located in the approximate center of the squama immediately superior to the external occipital protuberance. Notably, no child over the age of 1 year exhibits a lesion that would have been active at the time of death, but a number of older children and adults exhibit evidence of healed lesions in this same area on the occipital. The restricted nature of these lesions, in terms of both their locations and ages of those actively affected, suggests that the use of cradleboards may have been at least a contributing, if not initiatory, factor in their creation. Specifically, this study suggests that the pressure and friction of an infant's head against a cradleboard may have 1) produced ischemic ulcers, 2) produced the conditions favorable for bacterial infections such as impetigo or carbuncles, or 3) complicated the treatment of other infections appearing on the back of the scalp.