Elka Miller

Evaluation of subcortical white matter and deep white matter tracts in malformations of cortical development.

Summary:  Aims: Abnormal cortical development will lead to abnormal axons in white matter. The purpose was to investigate (1) the microstructural changes in subcortical white matter adjacent to malformations of cortical development (MCD) and (2) the deep white matter tracts using diffusion tensor imaging (DTI).

The old and the new: supratentorial MR findings in Chiari II malformation

ObjectiveThe objective of this study was to use magnetic resonance imaging to develop an improved morphological understanding of the abnormalities of the forebrain in Chiari II malformation.Materials and methodsSeventy-four patients with Chiari II malformations investigated between 1999 and 2007 were enrolled. Imaging was retrospectively reviewed by two pediatric neuroradiologists, with special attention given to diencephalon, midline commissures, hemispheric white matter, and cortex.ResultsAn abnormal gray matter structure that we called hypothalamic adhesion across the anterior-inferior portion of the third ventricle was noted in 48.6%. The anterior commissure was in a low position in the lamina terminalis in 38%. Gross abnormalities of the corpus callosum/hippocampal commissure were found in 57%; they were, however, different from the abnormalities seen in classical commissural agenesis. An abnormal bundle of white matter forming a callosal ridge was noted on the dorsal callosal surface in 60%; it is believed to represent the aberrant cingular bundle recently identified using diffusion tensor imaging. Hemispheric white matter could be considered as normal in 48%, deficient posteriorly in 55%, and globally in 10%. Cortical posterior medial stenogyria was observed in 72%. Gray matter heterotopias were found in 19%. The posterior limbic cortex was thin and dysplastic in 46%. Hippocampi were commonly abnormal (85%), with atypical sulcation of the adjacent temporo-mesial cortex (93%).ConclusionMajor structural abnormalities were common in Chiari II malformation and were probably not related to hydrocephalus. Important anatomical structures involved in neurocognitive function should be considered as factors in the prognostic assessment of Chiari II patients.

Evidence-Based Outcomes of Studies Addressing Diagnostic Accuracy of MRI of Juvenile Idiopathic Arthritis

OBJECTIVE Our objective was to semiquantitatively evaluate the diagnostic accuracy of MRI for evaluation of synovium and cartilage of peripheral joints in juvenile idiopathic arthritis (JIA) according to the levels of evidence and recommendations of the Canadian Task Force on Periodic Health Examination guidelines. CONCLUSION Articles were screened using MEDLINE, EMBASE, DARE, and the Cochrane Library. Two independent reviewers assessed whether the currently available MRI techniques are accurate for diagnosis of synovial hypertrophy and cartilage degeneration in children with JIA. Overall, there is fair (grade B) strength of evidence that MRI is an accurate diagnostic method for evaluating synovium and cartilage and for assessing clinical responsiveness to treatment in peripheral joints in JIA.

Brain and Bone Abnormalities of Thanatophoric Dwarfism

OBJECTIVE The purpose of this article is to present the imaging findings of skeletal and brain abnormalities in thanatophoric dwarfism, a lethal form of dysplastic dwarfism. CONCLUSION The bony abnormalities associated with thanatophoric dwarfism include marked shortening of the tubular bones and ribs. Abnormal temporal lobe development is a common associated feature and can be visualized as early as the second trimester. It is important to assess the brains of fetuses with suspected thanatophoric dwarfism because the presence of associated brain malformations can assist in the antenatal diagnosis of thanatophoric dwarfism.

Juvenile Idiopathic Arthritis of the Axial Joints: A Systematic Review of the Diagnostic Accuracy and Predictive Value of Conventional MRI

OBJECTIVE Our objective was to evaluate the diagnostic accuracy and reliability of MRI and its ability to depict responsiveness to treatment for the evaluation of the axial joints (temporomandibular joint [TMJ], spinal joints, and sacroiliac joints) in juvenile idiopathic arthritis (JIA). CONCLUSION There is fair (grade B) evidence that MRI is an accurate diagnostic method for evaluating early and intermediate changes in the TMJ in JIA and insufficient evidence to indicate MRI is an accurate diagnostic method for detecting JIA in the spinal (grade I) and sacroiliac (grade I) joints.

Fetal MR imaging of atelosteogenesis type II (AO-II)

The diastrophic dysplasia family of osteochondrodysplasias comprises a spectrum of skeletal diseases characterized by abnormal growth and remodelling of cartilage and bone. They are caused by mutations in the diastrophic dysplasia sulfate transporter (DTDST) gene. Different defects in this gene product give rise to the variety of phenotypes based on the level of residual transport capacity. We reported a case of a fetus with this spectrum, evaluated and diagnosed with fetal MRI.

Responsiveness of Bold MRI to Short-Term Temperature Changes in Rabbit Knees with Inflammatory Arthritis

Objectives: Tissue signal change caused by temperature-dependent alterations in the affinity of oxygen for hemoglobin contributes to BOLD contrast. Our goals were to test whether BOLD MRI contrast changes with short-term variations in joint temperature (internal responsiveness) and to determine whether an association exists between BOLD MRI and intraarticular pO2 and blood flow [reference standards] upon joint temperature changes (external responsiveness). Methods: Seven juvenile rabbits had the carrageenin (antigen)-injected knee imaged, 10 had the contralateral knee imaged and 11 had one of non-injection knees imaged. Assigned knees underwent experimentally forced increased (37°-42°C) or decreased (37°- 30°C) local temperature for 15-minute periods using heating/cooling pads and were subsequently imaged. Intra-articular pO2 and blood flow were measured in vivo during MRI scanning by polarographic probes. Results: Relative BOLD MRI measurements showed moderate (≤0.8 and >0.5) or large (>0.8) Standardized Response Mean (SRM) changes upon increased local temperature in contralateral knees. Significant substantial correlations were obtained between absolute BOLD MRI measurements and intraarticular pO2 measurements in contralateral knees (r = 0.71, P = 0.048) upon increased local temperature and high correlations were obtained in arthritic knees (r = 0.92, P = 0.004) upon decreased local temperature. Conclusions: BOLD MRI was responsive to short-term joint temperature changes. Imaging contralateral joints in addition to arthritic joints with BOLD MRI may help maximize identification of minimal early changes in subjects with arthritis if findings of this study are confirmed in larger sample size experiments.

Imaging for Early Assessment of Peripheral Joints in Juvenile Idiopathic Arthritis

■ Plain radiographs are the standard imaging tools for the diagnosis of JIA; however, they show low sensitivity (50%) and moderate specificity (85%) for detection of cartilage destruction (strong evidence).