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Interobserver reliability and diagnostic performance of Chiari II malformation measures in MR imaging--part 2.

Geerdink N, van der Vliet T, Rotteveel JJ, Feuth T, Roeleveld N, Mullaart RA - Childs Nerv Syst (2012)

Bottom Line: Three observers blindly and independently reviewed the MR images for 21 measures of the cerebellum, brainstem, and posterior fossa in three planes.Reliability was good for most measures, except for the degree of herniation of the vermis and tonsil.The measures mamillopontine distance and cerebellar width showed excellent diagnostic performance.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatric Neurology 801, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands. n.geerdink@cukz.umcn.nl

ABSTRACT

Purpose: Brain MR imaging is essential in the assessment of Chiari II malformation in clinical and research settings concerning spina bifida. However, the interpretation of MR images of the malformation is not always straightforward. Morphometric analyses of the extent of Chiari II malformation may improve the assessment. In an attempt to select appropriate morphometric measures for this purpose, we investigated the interobserver reliability and diagnostic performance of several morphometric measures of Chiari II malformation on MR images.

Methods: Brain MR images of 79 children [26 with open spinal dysraphism, 17 with closed spinal dysraphism, and 36 without spinal dysraphism; mean age 10.6 (SD 3.2; range, 6-16) years] were evaluated. All children had been assessed for Chiari II malformation (defined as cerebellar herniation in combination with open spinal dysraphism; n = 23). Three observers blindly and independently reviewed the MR images for 21 measures of the cerebellum, brainstem, and posterior fossa in three planes. The interobserver reliability was assessed by an agreement index (AI = 1 - RRE) and the diagnostic performance by receiver operating characteristic analyses.

Results: Reliability was good for most measures, except for the degree of herniation of the vermis and tonsil. Most values differed statistically significantly between children with and without Chiari II malformation. The measures mamillopontine distance and cerebellar width showed excellent diagnostic performance.

Conclusions: Morphometric measures may reliably quantify the morphological distortions of Chiari II malformation on MR images and provide additional tools to assess the severity of Chiari II malformation in clinical and research settings.

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Receiver operating characteristic curves for measures with a good diagnostic performance (AUC > 0.90). See Table 5 for further details
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Fig1: Receiver operating characteristic curves for measures with a good diagnostic performance (AUC > 0.90). See Table 5 for further details

Mentions: The diagnostic performance of the measures based on the data from observer A is presented in Table 5 and illustrated by ROC curves in Fig. 1. The AUC was substantial (>0.90) for five measures: foramen magnum diameter, pons length, pons thickness, and mamillopontine distance in the sagittal plane (Fig. 2), and cerebellar width in the axial plane (Fig. 3), but sensitivity or specificity were not all that high for pons length and pons thickness. Consistency of the performance of these five measures was evaluated using the measurement values of observers B and C (Table 6). In this analysis, only mamillopontine distance and cerebellar width maintained their excellent diagnostic performance. Despite the high sensitivity and specificity in the primary analysis, foramen magnum diameter failed to the consistency test.Table 5


Interobserver reliability and diagnostic performance of Chiari II malformation measures in MR imaging--part 2.

Geerdink N, van der Vliet T, Rotteveel JJ, Feuth T, Roeleveld N, Mullaart RA - Childs Nerv Syst (2012)

Receiver operating characteristic curves for measures with a good diagnostic performance (AUC > 0.90). See Table 5 for further details
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3376256&req=5

Fig1: Receiver operating characteristic curves for measures with a good diagnostic performance (AUC > 0.90). See Table 5 for further details
Mentions: The diagnostic performance of the measures based on the data from observer A is presented in Table 5 and illustrated by ROC curves in Fig. 1. The AUC was substantial (>0.90) for five measures: foramen magnum diameter, pons length, pons thickness, and mamillopontine distance in the sagittal plane (Fig. 2), and cerebellar width in the axial plane (Fig. 3), but sensitivity or specificity were not all that high for pons length and pons thickness. Consistency of the performance of these five measures was evaluated using the measurement values of observers B and C (Table 6). In this analysis, only mamillopontine distance and cerebellar width maintained their excellent diagnostic performance. Despite the high sensitivity and specificity in the primary analysis, foramen magnum diameter failed to the consistency test.Table 5

Bottom Line: Three observers blindly and independently reviewed the MR images for 21 measures of the cerebellum, brainstem, and posterior fossa in three planes.Reliability was good for most measures, except for the degree of herniation of the vermis and tonsil.The measures mamillopontine distance and cerebellar width showed excellent diagnostic performance.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatric Neurology 801, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands. n.geerdink@cukz.umcn.nl

ABSTRACT

Purpose: Brain MR imaging is essential in the assessment of Chiari II malformation in clinical and research settings concerning spina bifida. However, the interpretation of MR images of the malformation is not always straightforward. Morphometric analyses of the extent of Chiari II malformation may improve the assessment. In an attempt to select appropriate morphometric measures for this purpose, we investigated the interobserver reliability and diagnostic performance of several morphometric measures of Chiari II malformation on MR images.

Methods: Brain MR images of 79 children [26 with open spinal dysraphism, 17 with closed spinal dysraphism, and 36 without spinal dysraphism; mean age 10.6 (SD 3.2; range, 6-16) years] were evaluated. All children had been assessed for Chiari II malformation (defined as cerebellar herniation in combination with open spinal dysraphism; n = 23). Three observers blindly and independently reviewed the MR images for 21 measures of the cerebellum, brainstem, and posterior fossa in three planes. The interobserver reliability was assessed by an agreement index (AI = 1 - RRE) and the diagnostic performance by receiver operating characteristic analyses.

Results: Reliability was good for most measures, except for the degree of herniation of the vermis and tonsil. Most values differed statistically significantly between children with and without Chiari II malformation. The measures mamillopontine distance and cerebellar width showed excellent diagnostic performance.

Conclusions: Morphometric measures may reliably quantify the morphological distortions of Chiari II malformation on MR images and provide additional tools to assess the severity of Chiari II malformation in clinical and research settings.

Show MeSH
Related in: MedlinePlus