4/15/2021 Course Outline Pediatric Radiology: An Overview of Introduction to imaging the pediatric population Common Conditions Trauma Congenital conditions HEATHER L. MILEY, DC, MS, DACBR Scoliosis overview Arthritis Infection Other musculoskeletal disorders 1 2 Skeletal Development Bones take many years to grow and mature Intramembranous ossification Mesenchymal models of bones form during the Pediatric Imaging embryonic period, and direct ossification of the mesenchyme begins in the fetal period Endochondral ossification Cartilage models of the bones form from mesenchyme during the fetal period, and bone subsequently replaces most of the cartilage 3 4 Skeletal Development endochondral ossification Primary ossification center The main body of the bone model Shaft of a bone ossified from the primary ossification center is the diaphysis which grows as the bone develops Secondary ossification centers Appear in other parts of the developing bone after birth Parts of bone ossified from these centers are epiphyses Growth of a long bone at the epiphyseal plates https://courses.lumenlearning.com/wm-biology2/chapter/bone-growth-and-development/ 5 6 1 4/15/2021 Skeletal Development Physis Appears as a radiolucent line in the skeletally immature As the metaphysis and epiphysis mature and fuse, the physis thins, disappears, and endochondral ossification ceases A subchondral bone plate forms with horizontally- oriented trabeculae which appears as a radiopaque transverse fusion line (aka physeal scar) Case courtesy of Dr Matt Skalski, Radiopaedia.org, rID: 29729 7 8 Skeletal Development Apophysis A normal secondary ossification center located in the non-weight-bearing part of the bone Eventually fuses over time Process can be delayed, especially in female athletes Is a site of tendon or ligament attachment When unfused, can easily be mistaken for fractures Case courtesy of Dr Matt Skalski, Radiopaedia.org, rID: 27354 9 10 Imaging Guidelines * Epiphysis initially partially or MSK x-ray completely cartilaginous, rapidly Acute trauma – spine or extremity replaced by SOC until only articular cartilage (wavy arrow) remains Limping child up to age 5 Chronic pain ➢ growth plate stays relatively Back or neck pain constant during development; at Inflammatory back pain: known or suspected axial spondyloarthropathy the onset of skeletal maturation, narrows and becomes less Chronic extremity joint pain, suspected inflammatory arthritis hyperintense (straight arrow) and Clinically suspected vascular malformation of extremities then finally closes completely Malignant or aggressive primary musculoskeletal tumor staging and surveillance Primary bone tumors Can leave behind physeal scar (curved arrow) Soft tissue masses Stress fracture Suspected osteomyelitis, septic arthritis, or soft tissue infection Myelopathy or radiculopathy (spine) Ataxia (spine) Suspected congenital anomaly Imaging of Pediatric Growth Plate Disturbances. Jie C. Nguyen, B. Keegan Markhardt, Arnold C. Merrow, and Jerry R. Dwek. RadioGraphics 2017 37:6, 1791-1812 11 12 2 4/15/2021 Imaging Guidelines MRI or CT Internal derangement of joints (sports-related injuries) Tumors or infection Bone cancer or bone marrow for leukemia Congenital or acquired abnormalities of the spine or extremities Complex fractures Spinal cord 8 years https://radsource.us/developmental-variants/ 13 14 Imaging Guidelines Bone Marrow – MRI MSKUS Red marrow Developmental dysplasia of the hip Cellular, active, myeloid, or hematopoietic marrow Juvenile idiopathic arthritis Composed of cellular elements that include erythrocytes Cartilage/epiphyseal ossification centers that are not visualized on x- ray (red cells), granulocytes (white cells), and thrombocytes (platelets) Muscle hernia Posttraumatic abnormalities – brachial plexus injury, intramuscular Responsible for satisfying oxygenation needs, immunity, hematoma, myositis ossificans, foreign body, tendon laceration and coagulation Transient synovitis Osteoarticular and soft tissue infections Yellow marrow Soft tissue masses Fatty or inactive marrow Epidermoid or dermoid cysts Provide surface or nutritional support for red marrow Ganglion cysts elements Peripheral nerve sheath tumors (neurofibromas and schwannomas) Sparse vascular supply 15 16 Bone Marrow – MRI Amount and distribution of red and yellow marrow change with age Normal conversion from red to yellow marrow occurs in a predictable and progressive manner Completed by middle 20s Conversion proceeds from the extremities to the axial skeleton occurring in the distal bones of the extremities (hands and feet) first, and progressing finally to the proximal bones Occurs in a roughly symmetric manner on each side In the long bone, epiphyses and apophyses first, then diaphysis, followed by distal metaphysis, and finally proximal metaphysis Case courtesy of Dr Matt Skalski, Radiopaedia.org, rID: 21541 17 18 3 4/15/2021 Bone Marrow – MRI Rate of conversion from red to yellow marrow Age Group Marrow Findings Infants (<1 year) diffuse red marrow, except for ossified epiphyses and apophyses Congenital Conditions Children (1-10 years) yellow marrow below knees and elbows, and in diaphysis of femora and humeri Adolescents (10-20 years) progressive yellow marrow in distal and proximal metaphyses of proximal long bones Adults (>25 years) yellow marrow except in axial skeleton and proximal metaphyses of proximal long bones 19 20 Congenital Disorders of Bone Congenital – Skull Can be divided into: Parietal foramina Congenital anomalies Result from delayed/incomplete ossification of the Normal skeletal variants posterior aspect of the parietal bone near the Skeletal dysplasias sagittal suture Commonly encountered in clinical practice Transmits an emissary vein to the superior sagittal Some skeletal variants may simulate disease on x-ray sinus Can occur as a normal variant, or part of a Skeletal dysplasias are the result of faulty development and can congenital syndrome be grouped according to the features of the disease: Proximal or distal limb shortening Consider further imaging (CT or MRI) if larger than 5 Sclerosis of osseous structures mm as this can be associated with vascular anomalies (especially venous) Specific spinal abnormalities Agenesis or duplication of specific anatomic structures 21 22 Congenital – Spine Craniocervical junction (e.g., atlantooccipital assimilation, third occipital condyle, epitransverse and paracondylar process) Spina bifida occulta Block vertebra Including Klippel-Feil syndrome Odontoid anomalies (e.g., os odontoideum) Agenesis of the posterior neural arch (e.g., C1 posterior arch, articular process, pedicle, etc.) Hemivertebra Butterfly vertebra Cervical ribs Posterior ponticle Transitional segments Sprengel deformity Unfused secondary ossification centers Case courtesy of Benjamin Pereira Zimmermann, Radiopaedia.org, rID: 72098 23 24 4 4/15/2021 Congenital – Spine Atlanto-occipital assimilation Fusion of the atlas to the occiput = transitional vertebra 0.5% of the population Typically asymptomatic but symptoms from nerve or vascular compression can occur Need MRI with additional cuts through C0-C2 to include the transverse ligament Complete (C1 not identifiable) to incomplete (C1 partially identifiable) https://radiologykey.com/the-spine-congenital-and-developmental-conditions/ 25 26 Congenital – Spine Atlanto-occipital assimilation Associations: Fusion of C2 and C3 (50% of cases) Basilar invagination Cleft palate Cervical ribs Urinary tract anomalies Cranio-cervical instability https://www.rrnursingschool.biz/syndrome-omim/basilar-impression.html 27 28 Case courtesy of Assoc Prof Frank Gaillard, Radiopaedia.org, rID: 10365 https://www.semanticscholar.org/paper/Congenital-osseous-anomalies-of-the-upper-cervical-Hosalkar-Sankar/87e6da0d1d2e730f7ff81e8334cd99bafcfc978f 29 30 5 4/15/2021 Congenital – Spine Klippel-Feil syndrome A complex heterogenous condition that results in cervical vertebral fusion Two or more non-segmented cervical vertebrae Classic triad (50%) Short neck Low hairline Restricted neck motion https://radiologykey.com/the-spine-congenital-and-developmental-conditions/ 31 32 Congenital – Spine Congenital – Spine Klippel-Feil syndrome Klippel-Feil syndrome Associations: Can show fusion of many cervical and upper thoracic vertebrae; fusion of two or three vertebrae Sprengel deformity with associated hemivertebrae, atlanto-occipital Anomalies of the aortic arch and branching vessels fusion, or other cervical spine abnormalities; or Spinal scoliosis cervical fusion with lower thoracic or lumbar Intervertebral disc herniation vertebral fusion Cervical spondylosis Classification grouped by patterns of inheritance, associated anomalies, and the axial level of the Renal abnormalities most anterior fusion 33 34 Congenital – Spine Klippel-Feil syndrome X-ray: vertebral fusion, hemivertebrae, omovertebral bone, spina bifida, associated scoliosis and Sprengel deformity CT: may additionally demonstrate canal stenosis secondary to degenerative changes MRI: indicated in patients with neurologic deficits; excellent in demonstrating canal stenosis and cord compression, as well as disc bulge/herniation; can also reveal associated conditions such as myelomalacia, syrinx, diastematomyelia, and Chiari I malformation 5 yom Case courtesy of Dr Mostafa El-Feky, Radiopaedia.org, rID: 52725 35 36 6 4/15/2021 Congenital – Hip/Pelvis Developmental dysplasia