DOI: 10.1148/radiol.2401050674
Limbic Tract Anomalies in Pediatric Myelomeningocele and Chiari II Malformation: Anatomic Correlations with Memory and LearningInitial Investigation1
Behroze Vachha, MBBS, PhD,
Richard C. Adams, MD and
Nancy K. Rollins, MD
1 From Pediatric Developmental Disabilities, Texas Scottish Rite Hospital for Children, Dallas, Tex (B.V., R.C.A.); Departments of Pediatrics (B.V., R.C.A.) and Radiology (N.K.R.), University of Texas Southwestern Medical Center, Dallas, Tex; and Department of Radiology, Children's Medical Center of Dallas, 1935 Motor St, Dallas, TX 75235 (N.K.R.). Received April 22, 2005; revision requested June 16; revision received June 28; accepted July 8; final version accepted September 2.
Address correspondence to N.K.R. (e-mail: Nancy.rollins{at}childrens.com).

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Figure 1: Sagittal FT reconstruction image shows normal cingulum (thick arrows) and fornix (thin arrows) in 6-month-old boy with Chiari II malformation who was too young to undergo cognitive assessment. A = anterior, P = posterior.
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Figure 2: Transverse bottom-up FT reconstruction image of fornices (short arrows) and anterior commissure (long arrows) in 14-year-old boy with no memory or learning problems. Note the symmetric defects in the crura of the fornix (arrowheads). L = left, R = right.
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Figure 3a: Sagittal images show abnormal limbic fibers in 5-year-old girl with memory and learning deficits. (a) T1-weighted spin-echo MR image (400/12; two signals acquired) shows severe hindbrain deformity and dysmorphic corpus callosum. (b) FT reconstruction image shows incomplete atrophic cingulum (long arrows) and thin fornix (short arrows). A = anterior, P = posterior.
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Figure 3b: Sagittal images show abnormal limbic fibers in 5-year-old girl with memory and learning deficits. (a) T1-weighted spin-echo MR image (400/12; two signals acquired) shows severe hindbrain deformity and dysmorphic corpus callosum. (b) FT reconstruction image shows incomplete atrophic cingulum (long arrows) and thin fornix (short arrows). A = anterior, P = posterior.
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Figure 4: Sagittal FT reconstruction image in 14-year-old girl with general memory and learning impairment. Defect in right crus of the fornix (short straight arrows) and intact left fornix (curved arrow) are observed. Temporal segment of left cingulum (long straight arrow) is attenuated compared with the normal right temporal segment (arrowhead).
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Figure 5: Oblique sagittal FT reconstruction image in 5-year-old girl with Chiari II malformation complicated by agenesis of septum pellucidum. Cognitive testing was not performed. Fornices (long arrow) are caudally displaced and right cingulum (short arrow) is deficient, whereas left cingulum (arrowhead) is thin but intact. Rostral fibers of corpus callosum partially obscure cingulum. A = anterior, P = posterior.
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Figure 6a: Images show aberrant fibers of cingulum in 7-year-old boy with no memory and learning deficits. The cingulum and fornices are otherwise intact. (a) Sagittal T2-weighted fast spin-echo MR image (3500/120, two signals acquired) shows corpus callosum with dysgenesis, shortened in anteroposterior dimension with absence of splenium. Posterior fossa shows stigmata of Chiari II malformation. (b) Sagittal color map shows that corpus callosum is composed of red callosal fibers (short arrow) and green fibers (long arrow) derived from the cingulum and that they cannot be differentiated from each other on routine MR images. (c) Transverse top-down FT reconstruction image shows fibers of the cingulum (arrow) crossing obliquely over corpus callosum and normally positioned frontoparietal segments of the cingulum (arrowheads).
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Figure 6b: Images show aberrant fibers of cingulum in 7-year-old boy with no memory and learning deficits. The cingulum and fornices are otherwise intact. (a) Sagittal T2-weighted fast spin-echo MR image (3500/120, two signals acquired) shows corpus callosum with dysgenesis, shortened in anteroposterior dimension with absence of splenium. Posterior fossa shows stigmata of Chiari II malformation. (b) Sagittal color map shows that corpus callosum is composed of red callosal fibers (short arrow) and green fibers (long arrow) derived from the cingulum and that they cannot be differentiated from each other on routine MR images. (c) Transverse top-down FT reconstruction image shows fibers of the cingulum (arrow) crossing obliquely over corpus callosum and normally positioned frontoparietal segments of the cingulum (arrowheads).
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Figure 6c: Images show aberrant fibers of cingulum in 7-year-old boy with no memory and learning deficits. The cingulum and fornices are otherwise intact. (a) Sagittal T2-weighted fast spin-echo MR image (3500/120, two signals acquired) shows corpus callosum with dysgenesis, shortened in anteroposterior dimension with absence of splenium. Posterior fossa shows stigmata of Chiari II malformation. (b) Sagittal color map shows that corpus callosum is composed of red callosal fibers (short arrow) and green fibers (long arrow) derived from the cingulum and that they cannot be differentiated from each other on routine MR images. (c) Transverse top-down FT reconstruction image shows fibers of the cingulum (arrow) crossing obliquely over corpus callosum and normally positioned frontoparietal segments of the cingulum (arrowheads).
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Figure 7b: Moderate ventricular enlargement without shunt and anomalous cingulum in 13-month-old girl who had undergone prenatal closure of lumbar MM at 24 weeks gestational age. (a) Sagittal T1-weighted spin-echo MR image (400/12, two signals acquired) shows corpus callosum with dysgenesis. (b) Transverse top-down FT reconstruction image shows multiple white matter bundles (arrows) oriented anteroposteriorly above body of corpus callosum. The corpus callosum with dysgenesis is composed of callosal fibers and aberrant cingulum, and they cannot be differentiated on routine MR images.
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Figure 7a: Moderate ventricular enlargement without shunt and anomalous cingulum in 13-month-old girl who had undergone prenatal closure of lumbar MM at 24 weeks gestational age. (a) Sagittal T1-weighted spin-echo MR image (400/12, two signals acquired) shows corpus callosum with dysgenesis. (b) Transverse top-down FT reconstruction image shows multiple white matter bundles (arrows) oriented anteroposteriorly above body of corpus callosum. The corpus callosum with dysgenesis is composed of callosal fibers and aberrant cingulum, and they cannot be differentiated on routine MR images.
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Copyright © 2006 by the Radiological Society of North America.