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Essential features of Chiari II malformation in MR imaging: an interobserver reliability study--part 1.

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

Bottom Line: Brain MR imaging is essential in the assessment of Chiari II malformation in clinical and research settings concerning spina bifida.The interobserver reliability was assessed using κ statistics.Twenty-three of the features studied turned out to be unreliable, whereas the interobserver agreement was almost perfect (κ value > 0.8) for nine features (eight in the sagittal plane and one in the axial plane, but none in the coronal plane).

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 morphological features of the malformation on MR images may not always be straightforward. In an attempt to select those features that unambiguously characterize the Chiari II malformation, we investigated the interobserver reliability of all its well-known MR features.

Methods: Brain MR images of 79 children [26 presumed to have Chiari II malformation, 36 presumed to have no cerebral abnormalities, and 17 children in whom some Chiari II malformation features might be present; mean age 10.6 (SD 3.2; range, 6-16) years] were blindly and independently reviewed by three observers. They rated 33 morphological features of the Chiari II malformation as present, absent, or indefinable in three planes (sagittal, axial, and coronal). The interobserver reliability was assessed using κ statistics.

Results: Twenty-three of the features studied turned out to be unreliable, whereas the interobserver agreement was almost perfect (κ value > 0.8) for nine features (eight in the sagittal plane and one in the axial plane, but none in the coronal plane).

Conclusions: This study presents essential features of the Chiari II malformation on MR images by ruling out the unreliable features. Using these features may improve the assessment of Chiari II malformation in clinical and research settings.

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Related in: MedlinePlus

a Sagittal T1-weighted brain MR image in 16-year-old child with open spinal dysraphism. The image shows herniation of the vermis (large white arrow), herniation of the tonsil (large white open arrow), and medullary kinking (small white arrow); b sagittal T1-weighted brain MR image in 12-year-old child with open spinal dysraphism. The image shows herniation of the cerebellum (large white arrow). The vermis and tonsil cannot be demarcated from each other. Note the beaked tectum (small white arrow) and the hypoplastic tentorium. Also, note the downward displacement of the medulla and pons and the small fourth ventricle in both images
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Fig1: a Sagittal T1-weighted brain MR image in 16-year-old child with open spinal dysraphism. The image shows herniation of the vermis (large white arrow), herniation of the tonsil (large white open arrow), and medullary kinking (small white arrow); b sagittal T1-weighted brain MR image in 12-year-old child with open spinal dysraphism. The image shows herniation of the cerebellum (large white arrow). The vermis and tonsil cannot be demarcated from each other. Note the beaked tectum (small white arrow) and the hypoplastic tentorium. Also, note the downward displacement of the medulla and pons and the small fourth ventricle in both images

Mentions: The interobserver agreement of the applicable features is presented in Table 4. The right panel of the table shows the percentages of agreement and disagreement, while the left panel shows the κ values. The interobserver agreement among all three observers was almost perfect (κ value > 0.8) for the following features in the sagittal plane: Downward herniation cerebellum, Downward herniation tonsil, Downward displacement medulla, Downward displacement fourth ventricle, Medullary kinking, Abnormal width fourth ventricle, Hypoplastic tentorium, and Beaked tectum (Fig. 1). Only one feature in the axial plane (Small fourth ventricle) showed almost perfect agreement, while none of the features in the coronal plane did. The overall κ values for the remaining features ranged from 0.50 (Cerebellum wrapped around brainstem) to 0.75 (Downward displacement pons), except for a very low κ value for Enlarged massa intermedia (0.10). Table 4 also lists the κ values for pairs of observers. For seven features, the κ values differed substantially among pairs of observers: Downward herniation vermis, Upward herniation cerebellum, Downward displacement pons, and Abnormal course straight sinus in the sagittal plane; Cerebellum wrapped around brainstem in the axial plane; and Indentation and Gyral interdigitation in the coronal plane. In general, the agreement between observers A and B was stronger than the agreement of each of them with observer C.Table 4


Essential features of Chiari II malformation in MR imaging: an interobserver reliability study--part 1.

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

a Sagittal T1-weighted brain MR image in 16-year-old child with open spinal dysraphism. The image shows herniation of the vermis (large white arrow), herniation of the tonsil (large white open arrow), and medullary kinking (small white arrow); b sagittal T1-weighted brain MR image in 12-year-old child with open spinal dysraphism. The image shows herniation of the cerebellum (large white arrow). The vermis and tonsil cannot be demarcated from each other. Note the beaked tectum (small white arrow) and the hypoplastic tentorium. Also, note the downward displacement of the medulla and pons and the small fourth ventricle in both images
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3376258&req=5

Fig1: a Sagittal T1-weighted brain MR image in 16-year-old child with open spinal dysraphism. The image shows herniation of the vermis (large white arrow), herniation of the tonsil (large white open arrow), and medullary kinking (small white arrow); b sagittal T1-weighted brain MR image in 12-year-old child with open spinal dysraphism. The image shows herniation of the cerebellum (large white arrow). The vermis and tonsil cannot be demarcated from each other. Note the beaked tectum (small white arrow) and the hypoplastic tentorium. Also, note the downward displacement of the medulla and pons and the small fourth ventricle in both images
Mentions: The interobserver agreement of the applicable features is presented in Table 4. The right panel of the table shows the percentages of agreement and disagreement, while the left panel shows the κ values. The interobserver agreement among all three observers was almost perfect (κ value > 0.8) for the following features in the sagittal plane: Downward herniation cerebellum, Downward herniation tonsil, Downward displacement medulla, Downward displacement fourth ventricle, Medullary kinking, Abnormal width fourth ventricle, Hypoplastic tentorium, and Beaked tectum (Fig. 1). Only one feature in the axial plane (Small fourth ventricle) showed almost perfect agreement, while none of the features in the coronal plane did. The overall κ values for the remaining features ranged from 0.50 (Cerebellum wrapped around brainstem) to 0.75 (Downward displacement pons), except for a very low κ value for Enlarged massa intermedia (0.10). Table 4 also lists the κ values for pairs of observers. For seven features, the κ values differed substantially among pairs of observers: Downward herniation vermis, Upward herniation cerebellum, Downward displacement pons, and Abnormal course straight sinus in the sagittal plane; Cerebellum wrapped around brainstem in the axial plane; and Indentation and Gyral interdigitation in the coronal plane. In general, the agreement between observers A and B was stronger than the agreement of each of them with observer C.Table 4

Bottom Line: Brain MR imaging is essential in the assessment of Chiari II malformation in clinical and research settings concerning spina bifida.The interobserver reliability was assessed using κ statistics.Twenty-three of the features studied turned out to be unreliable, whereas the interobserver agreement was almost perfect (κ value > 0.8) for nine features (eight in the sagittal plane and one in the axial plane, but none in the coronal plane).

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 morphological features of the malformation on MR images may not always be straightforward. In an attempt to select those features that unambiguously characterize the Chiari II malformation, we investigated the interobserver reliability of all its well-known MR features.

Methods: Brain MR images of 79 children [26 presumed to have Chiari II malformation, 36 presumed to have no cerebral abnormalities, and 17 children in whom some Chiari II malformation features might be present; mean age 10.6 (SD 3.2; range, 6-16) years] were blindly and independently reviewed by three observers. They rated 33 morphological features of the Chiari II malformation as present, absent, or indefinable in three planes (sagittal, axial, and coronal). The interobserver reliability was assessed using κ statistics.

Results: Twenty-three of the features studied turned out to be unreliable, whereas the interobserver agreement was almost perfect (κ value > 0.8) for nine features (eight in the sagittal plane and one in the axial plane, but none in the coronal plane).

Conclusions: This study presents essential features of the Chiari II malformation on MR images by ruling out the unreliable features. Using these features may improve the assessment of Chiari II malformation in clinical and research settings.

Show MeSH
Related in: MedlinePlus