Quantitative analysis of cranial-orbital changes in infants with anterior synostotic plagiocephaly

Extremely Preterm Infants with a Near-total Absence of Cerebellum: Usefulness of Quantitative Magnetic Resonance in Predicting the Motor Outcome

This study aims to evaluate in extremely premature infants the severity of brain structural injury causing total absence or near-total absence of cerebellar hemispheres by using MRI visual and volumetric scoring systems. It also aims to assess the role of the score systems in predicting motor outcome. We developed qualitative and quantitative MRI scoring systems to grade the overall brain damage severity in 16 infants with total absence or near-total absence of cerebellar hemispheres. The qualitative scoring system assessed the severity of macrostructural abnormalities of cerebellum, brainstem, supratentorial gray and white matters, ventricles while the quantitative scoring system weighted the loss of brain tissue volumes, and gross motor function classification system (GMFCS) was used to assess motor function at 1- and 5-year follow-ups.Positive correlations between both MRI scores and GMFCS scales were detected at follow-ups (p > 0.05), but only the volumetric score could identify those infants developing higher levels of motor impairment.Brain volumetric MRI offers an unbiassed assessment of prenatal brain damage. The quantitative scoring system, performed at term equivalent age, can be a helpful tool for predicting the long-term motor outcome in extremely preterm infants with a near-total absence of cerebellum.

Anterior Synostotic Plagiocephaly: A Quantitative Analysis of Craniofacial Features Using Computed Tomography

The premature fusion of one coronal suture causes anterior synostotic plagiocephaly (ASP), which results in overt craniofacial dysmorphology that could be challenging to correct. This study aimed to document and compare the morphometry of the anterior cranial fossa (ACF), orbit, and ear on the ipsilateral (synostotic) and contralateral (nonsynostotic) sides in a select cohort of South African patients with ASP, using computed tomography (CT) scans. The dimensions of the ACF, orbit and the position of the ear on the ipsilateral and contralateral sides were measured using a set of anatomical landmarks on 2-dimensional CT scans of 18 consecutive patients diagnosed with nonsyndromic ASP. The differences between the ipsilateral and contralateral sides were calculated and expressed as a percentage of the contralateral side. All ACF parameters decreased significantly on the ipsilateral side when compared to the contralateral side, resulting in the volume of the ACF being the most affected (-27.7%). In terms of the orbit, on the ipsilateral side, the length-infraorbital rim, height, and surface area parameters increased significantly, with the height being the most affected (24.6%). The remaining orbital parameters (length-supraorbital rim, breadth and volume) decreased significantly, with the length-supraorbital rim parameter being the most affected (-10.8%). The ipsilateral ear was found to be displaced anteriorly (9.33 mm) and caudally (5.87 mm) from the contralateral ear. These measures may be useful to surgeons during corrective surgery by indicating the degree of the asymmetry on each side, making it easier to plan the technique and extent of surgical correction of the affected structures.

Severity of Unilateral Coronal Synostosis Linked to Intracranial Volume

ABSTRACT

Severity of unilateral coronal synostosis (UCS) varies and can affect intracranial volume (ICV), and intracranial pressure. Correlation between ICV and severity according to Utrecht Cranial Shape Quantifier and presence of papilledema as sign of raised intracranial pressure is determined. The authors included patients with UCS (≤18 months). Intracranial volume was calculated on preoperative CT scans by manual segmentation (OsiriX [Fondation OsiriX, Geneva, Switzerland]). Calculated ICV was compared to Lichtenberg normative data for control patients. When present, papilledema was noted. Utrecht Cranial Shape Quantifier was used to quantify severity using the variables: asymmetry ratio of frontal peak and ratio of frontal peak gradient. Severity of UCS was correlated to ICV using Pearson correlation coefficient. Mean age at CT scan of patients with UCS was 7 months (1-18 months). Mean calculated ICV was 870.96 mL (617.31-1264.46 mL). All patients had ICV between ± 2 SD curves of Lichtenberg; 10 had an ICV between -1 SD and +1 SD. Majority of ICV in girls was at or larger than normative mean, in boys ICV was mostly lower than normative mean. Pearson correlation coefficient between severity of UCS and ICV was negligible (r = -0.28). Preoperative papilledema during fundoscopy was found in 4.5% (1/22; ICV 1003.88 mL; severe UCS). Therefore, severity of UCS does not correlate to ICV. Despite varying severity of UCS, ICV remains within normal ranges.

Orbital volume, ophthalmic sequelae and severity in unilateral coronal synostosis

PURPOSE

Unilateral coronal synostosis (UCS) results in an asymmetrical skull, including shallow and asymmetrical orbits, associated with reduced orbital volume and high prevalences of ophthalmic sequelae. Aim is to link orbital volumes in patients with UCS to severity according to UCSQ (Utrecht Cranial Shape Quantifier) and presence of ophthalmic sequelae.

METHODS

We included preoperative patients with UCS (≤ 18 months). Orbital volume was measured on CT scans by manual segmentation (Mimics software (Materialise, Leuven, Belgium)), and severity of UCS was determined by UCSQ. Orbital volume of affected side was compared to unaffected side using Wilcoxon signed rank test. Orbital volume ratio was calculated (affected/unaffected volume) and compared to the category of UCSQ by Kruskal-Wallis test. Opthalmic sequelae were noted.

RESULTS

We included 19 patients (mean age 7 months). Orbital volume on affected side was significantly lower (p = 0.001), mean orbital volume ratio was 0.93 (SD 0.03). No significant differences in group means of orbital volume ratio between different levels of severity of UCSQ were found (Kruskal-Wallis H (2) = 0.873; p > 0.05). Ophthalmic sequelae were found in 3 patients; one had adduction impairment and strabismus (mild UCS), one had astigmatism (moderate UCS), and one had abduction impairment (on both ipsi- and contralateral side) and vertical strabismus (severe UCS).

CONCLUSION

No association between orbital volume ratio and severity of UCS was found. Side-to-side asymmetry in orbital volume was noted. No association between either preoperative orbital volume ratio or severity of UCS and the presence of preoperative ophthalmic sequelae was found.

Statistical shape analyses of trigonocephaly patients

PURPOSE

Surgery is the first treatment option for patients with metopic craniosynostosis. Fronto-orbital advancement is the preferred method for correction of isolated trigonocephaly, but it is hard to understand whether surgery has been successful mainly in an early period. We aim to investigate the shape differences in the head shapes of trigonocephaly patients compared between preoperative and postoperative term.

METHODS

Cranial shape data were collected from the two-dimensional digital images. The Generalized Procrustes analysis was used to obtain mean shapes of the preoperative and postoperative term. The shape deformation of the frontal calvarium from preoperative to the postoperative term was evaluated using the thin-plate spline (TPS) method.

RESULTS

There was significant cranial shape difference between preoperative and postoperative term. The high-level deformations for preoperative to postoperative term determined seen in TPS graphic. Highest deformation was observed at the bifrontal dimension especially at nasion and posterior edge of the forehead.

CONCLUSIONS

In this study, we showed that the shape difference and structural deformation of the calvarium were correlated with the metopic craniosynostosis. The present study also shows that preoperative and postoperative head shapes of patients with trigonocephaly can be compared using the landmark-based geometrical morphometric method by taking into consideration the topographic distribution.