Pediatric case of the day. Chondroblastoma.
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Child↗
Biomedical subjects
D Jaramillo
Publications and source records attributed to D Jaramillo.
Gadolinium-enhanced MR imaging demonstrates abduction-caused hip ischemia and its reversal in piglets.
PURPOSE: To determine if gadolinium-enhanced MR imaging can detect early reversible ischemia of the capital femoral epiphysis and physis induced by hip hyperabduction in piglets. MATERIALS AND METHODS: Thirteen 1- to 3-week-old piglets were placed in maximal bilateral hip abduction and then studied with dynamic gadolinium-enhanced MR imaging 1-6 hr later to assess ischemia of the 26 femoral heads. The piglets were then allowed to ambulate freely for 1 or 7 days and reimaged in neutral position to assess reperfusion. We evaluated enhancement on MR images and compared them with histologic findings. RESULTS: Decreased or absent enhancement, interpreted as ischemia, developed after maximal hip abduction in all 26 cartilaginous epiphyses and 85% of the 26 physes. The most frequently seen abnormality was a sharply marginated, nonenhancing area in the anterior part of the femoral head. A smaller area of decreased enhancement developed in the posterior part of the femoral head adjacent to the acetabular rim. The secondary center of ossification was ischemic in 10 (56%) of the 18 hips after 1 hr of abduction and in all 8 hips after 4 or 6 hr (p = .02). The overall severity of ischemia was greater with longer abduction times (p < .001) and greater degrees of abduction (p < .01). Reperfusion was complete in two (17%) of the 12 hips after 1 day of ambulation and in all 10 (100%) after 1 week of ambulation. CONCLUSION: Enhanced MR imaging detects early ischemia of the epiphyseal and physeal cartilage and the epiphyseal marrow. In piglets, ischemia due to maximal abduction is reversible if corrected within 6 hr.
Age Factors↗
Pediatric musculoskeletal neoplasms. Evaluation with MR imaging.
MR imaging is an essential tool for the evaluation of musculoskeletal neoplasms in children. It provides useful information for diagnosis, determination of extent of disease, assessment of response to treatment, and detection of complications and effects of therapy. This article reviews the current role of MR imaging in each of these situations. A protocol for the evaluation of these lesions is suggested. Also addressed are issues related to differentiating pathologic conditions, normal marrow, and cartilaginous structures of the pediatric skeleton.
Bone Neoplasms↗
Trends in papers presented at meetings of the Society for Pediatric Radiology.
The abstracts of papers presented at the 1959-1994 meetings of the Society for Pediatric Radiology were reviewed and tabulated for organ system and imaging modality chiefly discussed and for number of authors per paper. Among organ systems, the musculoskeletal system and extremities were favored at first, then relatively ignored, then favored again. Interest in the central nervous system and head has been at a high level for the last decade. In modalities, plain radiography and fluoroscopy were dominant for more than 20 years but have now fallen to a much lower level of interest. Ultrasonography, magnetic resonance imaging, and computed tomography have passed all the older techniques and, collectively, have accounted for a large majority of the presentations for the last decade. Changes have been much greater in imaging techniques employed than in organ systems discussed. The number of authors per paper presented grew from 1.0 in 1959 to 1.7 for the 1960-1964 period to 4.1 for the 1990-1994 period.
Congresses as Topic↗
Gadolinium-enhanced MR imaging demonstrates abduction-caused hip ischemia and its reversal in piglets.
Purpose. To determine whether gadolinium-enhanced MR imaging can detect early reversible ischemia of the capital femoral epiphysis and physis induced by hip hyperabduction in piglets. Materials and methods. Thirteen 1- to 3-week-old piglets were placed in maximal abduction of both hips and studied with dynamic gadolinium-enhanced MR imaging 1-6 h later to assess ischemia of the 26 femoral heads. They were then allowed to ambulate freely for 1 or 7 days, and reimaged in neutral position to assess reperfusion. Enhancement was evaluated on MR images and compared with histologic findings.Results. Ischemia after hyperabduction developed in all 26 cartilaginous epiphyses and in 85 % of the physes. The most frequent abnormality was a sharply marginated nonenhancing area in the anterior part of the femoral head. A smaller area of ischemia developed in the posterior part of the femoral head, adjacent to the acetabular rim. The secondary center of ossification was ischemic in 56 % of the hips after 1 h of abduction and in all hips after 4 or 6 h (p = 0.02). The overall severity of ischemia was greater with increasing abduction time (p < 0.001) and increasing degree of abduction (p < 0.01). There was partial reperfusion in 83 % of the hips after 1 day of ambulation and complete reperfusion in all 26 hips (100 %) after 1 week.Conclusion. Enhanced MRI detects early ischemia of the epiphyseal and physeal cartilage and the epiphyseal marrow. In piglets, ischemia due to hyperabduction is reversible if corrected within 6 h.
Animals↗
Normal maturing distal tibia and fibula: changes with age at MR imaging.
PURPOSE: To describe the normal appearance of the maturing distal tibia and fibula at magnetic resonance (MR) imaging. MATERIALS AND METHODS: The authors retrospectively studied 50 MR examinations of patients aged 2 months to 21 years, dividing them into six developmental groups according to the appearance of the distal tibia and fibula. Epiphyseal ossification, physeal closure, and the signal characteristics of physeal cartilage were evaluated. RESULTS: Distal tibial epiphyseal ossification and physeal closure both began anteromedially and usually occurred earlier than in the fibula. The tibial physis developed an anteromedial undulation (Kump hump) before closure; volume averaging at the Kump hump simulated premature closure. The cartilaginous epiphysis had a lower signal intensity than the physis on T2-weighted images. The physis was most conspicuous on gradient-recalled-echo and fat-suppressed spin-echo proton-density-weighted images. CONCLUSION: Developmental cartilaginous and bone changes in the distal tibia and fibula follow a definite pattern and are well seen at MR imaging.
Adolescent↗
Cartilaginous abnormalities and growth disturbances in Legg-Calvé-Perthes disease: evaluation with MR imaging.
PURPOSE: To evaluate the magnetic resonance (MR) imaging appearance of cartilaginous abnormalities in Legg-Calvé-Perthes (LCP) disease and their association with growth arrest. MATERIALS AND METHODS: Twenty-seven MR images and radiographs of 25 hips in 23 patients were reviewed for epiphyseal, physeal, and metaphyseal abnormalities. Follow-up radiographs (mean time, 20.5 months) were evaluated for growth arrest. RESULTS: Epiphyseal abnormality seen in 74% of cases was not related to growth disturbances. Transphyseal bone bridging on MR images, the strongest predictor of abnormal growth (P < .01), was found in 63% of femurs. MR imaging helped detect physeal abnormalities with greater sensitivity (94%), specificity (89%), and positive predictive value (94%) than radiography. Metaphyseal extension of physeal cartilage seen in 81% of cases was associated with growth abnormality (P < .01), particularly when detected at radiography. CONCLUSION: Cartilaginous physeal and metaphyseal abnormalities in LCP disease are common and frequently result in growth arrest.
Adolescent↗
Osteomyelitis and septic arthritis in children: appropriate use of imaging to guide treatment.
Modern imaging techniques have become essential components of the management of acute osteomyelitis and septic arthritis in children. This article addresses the role of these techniques, based on clinical practice guidelines recently developed at a children's hospital by an interdisciplinary group. The recommendations reflect a review of the literature and an analysis of our own experience with 84 children treated for musculoskeletal sepsis during the past 3 years. We attempt to optimize imaging resources by analyzing the unique aspects of these infections in the pediatric skeleton, the clinical needs at different stages of the disease, and the relative strengths and weaknesses of the various imaging procedures. Our goal was to define the use of imaging in cases of osteomyelitis and septic arthritis in children in specific clinical scenarios in which additional information is likely to lead to management modification.
Acute Disease↗
Temporomandibular joint disc replacement made by tissue-engineered growth of cartilage.
OBJECTIVE: To test the effectiveness of the new technique of tissue-engineered growth of cartilage, temporomandibular joint (TMJ) disc replacements were created by seeding dissociated chondrocytes on synthetic, three-dimensional, bioresorbable polymer constructs of a predetermined anatomic shape, incubating the cell-polymer constructs in vitro, and transplanting them into test animals. MATERIALS AND METHODS: Twelve highly porous and bioresorbable cell-transplantation devices in the shape of TMJ discs were created using biodegradable polylactid and polyglycolic acid fibers. Bovine articular cartilage was dissociated into chondrocytes and the cells were allowed to attach to the three-dimensional polymer scaffolds and multiply in vitro. After 1 week, the cell-polymer constructs were implanted subcutaneously into nude mice. The neocartilage was assessed by magnetic resonance imaging (MRI) techniques, gross inspection, histology, and biomechanical and biochemical analysis after 12 weeks. RESULTS: All implants seeded with chondrocytes showed gross evidence of histologically organized hyaline cartilage. The scaffolds maintained their specific shape. They not only showed appropriate intrinsic stability during neomorphogenesis of cartilage in vitro and in vivo, but also seemed to guide the growth of cartilage. The presence of sulfated glycosaminoglycans was shown by aldehyde fuchsin alcian blue staining of the specimens. Type II collagen, considered to be indicative of cartilage formation, was found in the specimens tested. MRI showed signal characteristics similar to those of hyaline cartilage. Analysis of neocartilage force/displacement curves and aqueous phase compliance using a closed compression chamber suggested that the ability of the constructs to resist deformation was similar to that of native donor cartilage. CONCLUSION: The technology of tissue-engineered growth of cartilage on individually designed scaffolds may have many applications not only in reconstructive surgery of the TMJ, but also in craniomaxillofacial, plastic, and orthopedic surgery.
Animals↗
Comparison between fast spin-echo and conventional spin-echo imaging of normal and abnormal musculoskeletal structures in children and young adults.
RATIONALE AND OBJECTIVES: The differences in imaging characteristics between conventional and fast spin-echo studies of the skeletons of children and young adults were evaluated. METHODS: Concurrent conventional and fast spin-echo studies of 23 patients were compared by measuring signal intensity, contrast, and, subjectively, conspicuity of normal and abnormal musculoskeletal structures. RESULTS: Fast proton-density-weighted images had lower signal-to-noise ratios of muscle, fat, and physeal, epiphyseal, and articular cartilage. Using more than three echoes for proton-density images resulted in blurring and decreased lesion conspicuity. On fast T2-weighted images, there was greater conspicuity of normal cortex, ligaments, and muscle; but less contrast between fat and water because of a higher signal-to-noise ratio of fat. When both sequences were obtained with similar image quality, fast spin-echo was 40% faster. CONCLUSION: Fast spin-echo studies allows faster imaging, but can have blurring on proton-density-weighted images and decreased fat-water contrast on T2-weighted images.
Adipose Tissue↗
Patellar sleeve fracture: demonstration with MR imaging.
PURPOSE: To demonstrate the magnetic resonance (MR) imaging characteristics of patellar sleeve fracture, a cartilaginous avulsion from the lower pole of the patella occurring during forceful contraction of the quadriceps muscle against a partially flexed knee. MATERIALS AND METHODS: The authors evaluated radiographs and MR images from three children with suspected sleeve fractures. RESULTS: Radiographs showed small bone fragments avulsed from the lower patella in two children and no bone abnormality in one. MR imaging demonstrated separation of most of the cartilaginous lower patella in all children, definite intraarticular extension in one, and possible intraarticular extension in another. CONCLUSION: MR imaging can help determine the need for surgery by depicting the extent of cartilaginous injury and displacement of fracture fragments.
Cartilage↗
Dysraphic myelodysplasias associated with urogenital and anorectal anomalies: prevalence and types seen with MR imaging.
OBJECTIVE: The purpose of this study was to determine by MR imaging the prevalence and types of dysraphic abnormalities of the spinal cord (i.e., myelodysplasias) associated with urogenital and anorectal malformations of childhood. MATERIALS AND METHODS: Since 1987, 92 patients with imperforate anus complex, cloacal malformation, and cloacal exstrophy have had MR imaging as a screening examination for occult dysraphic myelodysplasia. The prevalence and types of myelodysplasia were determined for each group. RESULTS: The prevalence of dysraphic myelodysplasia in each group of children was 17% (1/6) for low imperforate anus (ectopic anus), 34% (11/32) for high imperforate anus (with fistulization), 46% (19/41) for cloacal malformation, and 100% (13/13) for cloacal exstrophy. The most common abnormalities in each group were tethered cord with intradural or filar lipoma in imperforate anus; low-placed or dysplastic conus medullaris and tethered cord with lipoma or myelolipoma in cloacal malformation; and lipomyelocele, lipomyelomeningocele, or lipomyelocystocele in cloacal exstrophy. CONCLUSION: Our results show that the prevalence of myelodysplasia as seen on MR imaging is high in patients with urogenital and anorectal anomalies.
Anus, Imperforate↗
Atypical idiopathic scoliosis: MR imaging evaluation.
The authors analyzed the clinical and imaging findings in 30 consecutive pediatric, adolescent, and young adult patients who underwent MR imaging because of atypical features of idiopathic scoliosis. Atypical clinical and plain radiographic features included early onset (n = 4), rapid progression (n = 19), pain (n = 17), other neurologic symptoms or signs (n = 12), associated syndromes (n = 4), a convex left thoracic or thoracolumbar curve (n = 18), a kyphotic component (n = 7), and pedicle thinning (n = 4). MR imaging demonstrated 17 abnormalities in 11 patients: lumbar disk protrusions (n = 1), patulous intradural space (dural ectasia) (n = 3), hydrosyringomyelia (n = 7), Chiari I malformation (n = 5), and cord astrocytoma (n = 1). Significant associations with abnormal MR imaging findings were shown for patients with pain, weakness, abnormal neurologic findings, and atypical curvatures. Furthermore, there was a striking association of convex left thoracic or thoracolumbar scoliosis with hydrosyringomyelia (six of seven cases). On the basis of these results, "atypical" spinal curvatures at radiography and "atypical" clinical features should prompt performance of additional diagnostic studies.
Adolescent↗
Indirect trauma to the growth plate: results of MR imaging after epiphyseal and metaphyseal injury in rabbits.
Abnormalities of the growth plate secondary to epiphyseal and metaphyseal injury were studied with magnetic resonance (MR) imaging, radiography, and histologic examination in 20 rabbits. Epiphyseal injury resulted in either the formation of a bony bridge across the growth plate or focal curving of the growth plate caused by a decrease in longitudinal growth. Metaphyseal injury resulted in interference with endochondral ossification, thickening of the growth plate, and extension of cartilage into the metaphysis. Serial MR images obtained during the first 6 weeks after injury showed persistence of abnormalities of the growth cartilage after epiphyseal injury, but resolution of abnormalities after metaphyseal injury. Abnormalities of the cartilage were best seen on T2-weighted images. Gadolinium enhancement showed reconstitution of metaphyseal vascularity after metaphyseal injury but did not enable detection of transphyseal vascularity after epiphyseal injury until a bony bridge formed.
Animals↗
Conversion of bone marrow in the humerus, sternum, and clavicle: changes with age on MR images.
To study the normal conversion of bone marrow in the humerus, sternum, and clavicle, 101 T1-weighted magnetic resonance (MR) studies obtained in 91 patients aged 2 days to 37 years were retrospectively evaluated. Conversion from hypointense (red) to hyperintense (yellow) bone marrow was assessed by comparison of signal intensity of the bone marrow with that of muscle and fat. Conversion began in the proximal humeral epiphysis (in 16 of 21 adequate studies [76%]), humeral diaphysis (17 of 30 adequate studies [57%]), and distal metaphysis (16 of 25 adequate studies [64%]) before age 1 year and was nearly complete in these regions (20 of 22 adequate studies [91%], 20 of 21 adequate studies [95%], and five of seven adequate studies [71%]) in examinations of children aged 1-5 years. In the proximal humeral metaphysis, conversion was seen in 21 of 22 adequate studies (95%) in children aged 1-5 years and was nearly complete in all by age 20 years. Conversion began in the sternum (six of six studies [100%] in children aged 6-10 years) and clavicle (six of eight studies [75%] in children aged 6-10 years) before age 11 years but was never complete. Bone marrow conversion in the humerus, sternum, and clavicle follows a well-defined pattern and is depicted earlier by MR imaging than one would expect on the basis of histologic data.
Adolescent↗
Metaphyseal abnormalities in children: pathophysiology and radiologic appearance.
The most active site of formation of bone in children is the metaphysis. Systemic and local diseases are reflected by alterations in the morphology of this region. In this pictorial essay, we examine several patterns of metaphyseal abnormalities seen on radiologic images and review the associated pathophysiology. Differential diagnosis may be aided by considering the pathologic mechanisms responsible for the various metaphyseal alterations.
Adolescent↗
Magnetic resonance imaging of the epiphysis: an experimental study.
The purpose of this study was to determine if metabolically altered cartilage could be distinguished from normal cartilage in the epiphysis by magnetic resonance imaging. Epiphysis from ten New Zealand White rabbits and five newborn lambs were imaged before and after heat-killing. The physiological change produced was documented with tritiated thymidine and radioactive sulfate autoradiography. Magnetic resonance imaging could detect differences in the tissues produced by heat-killing. The changes were most pronounced in the marrow, less pronounced in the epiphyseal cartilage and least pronounced but still detectable in the growth plate.
Animals↗