Parnell Shawn

Final Pr. ID: Poster #: EDU-080

The skeletal dysplasias are a large diverse group of several hundred disorders which are marked by abnormal bone and cartilage growth with resultant short stature. Dysplasias have been divided into larger groups according to common radiographic and/or genetic mutations. The purpose of this educational exhibit is to highlight one of these major groups, which are characterized by mutations of type 2 collagen. Read More

Authors:  Parnell Shawn

Keywords:  skeletal dysplasia, musculoskeletal, type 2 collagen, skeletal survey, dwarfism

Averill Lauren,  Tomatsu Shunji,  Theroux Mary

Final Pr. ID: Poster #: CR-044

Morquio A syndrome is an autosomal recessive lysosomal storage disorder characterized by skeletal dysplasia and progressive disability due to orthopedic complications, spinal cord compression and airway compromise. Although the bony changes and cervical spine instability have been well described in the radiology literature, the importance of imaging the airway in these patients has received scant attention. The purpose of this poster is to illustrate the progressive abnormality of the thoracic inlet and trachea seen in children and young adults with Morquio A syndrome.
The interplay of pectus carinatum, hypertrophied clavicular heads and upper thoracic kyphosis leads to bony narrowing of the thoracic inlet. Furthermore, glycosaminoglycan deposition degrades the structural integrity of the tracheal wall, creating a twisted and floppy airway. Additional crowding by a crossing tortuous right brachiocephalic artery and sometimes the thyroid gland contribute to progressive narrowing of the trachea at the thoracic inlet. Imbalance of growth between the skeleton and the airway and blood vessels may also play a role.
We present a series of patients with Morqiuo A syndrome, with multimodality imaging depicting the complex anatomy of the thoracic inlet contributing to airway compromise. Radiographs of the neck, chest or spine can suggest airway narrowing with a tilted hourglass shape of the trachea seen in the frontal projection; lateral views, though, are often limited. MRI of the cervical spine, frequently acquired to evaluate the craniocervical junction, also allows for assessment of the thoracic inlet including the trachea and crossing right brachiocephalic artery. CT angiogram of the chest can more clearly delineate vascular, bony and airway relationships in individuals with declining respiratory function or unexpected airway difficulty during anesthetic management. Three dimensional rendering and airway fly-through techniques may help guide anesthetic care and, in extreme cases, airway reconstruction. The imaging features of the thoracic inlet in this group of Morquio A patients are correlated with clinical phenotype, pulmonary function tests, and bronchoscopy when available. Read More

Authors:  Averill Lauren , Tomatsu Shunji , Theroux Mary

Keywords:  trachea, skeletal dysplasia, brachiocephalic artery

Parikh Ashishkumar,  Luo Yu,  Spottswood Stephanie

Final Pr. ID: Poster #: CR-036

First described by Rathbun in 1948, hypophosphatasia is an inherited metabolic disorder arising from the deficient activity of the tissue-nonspecific isoenzyme of alkaline phosphatase. There are several different types and varying clinical presentations of hypophosphatasia, characterized according to their age of onset by Fraser in 1957. In addition, the severity of the radiographic findings is inversely correlated with the age of presentation, with older patients presenting with less severe forms of the disease. Classically, the radiographic findings resemble rickets/osteomalacia, but in the presence of normal Vitamin D metabolism. Additional findings associated with hypophosphatasia are Bowdler spurs, which are transverse bony spurs in the radius, fibula and ulna and central lucencies or “punched out” lesions in the metaphysis, particularly of the knee (Case 1). In this case series of 3 patients, these characteristic radiographic features as depicted on skeletal surveys, along with their clinical manifestations, diagnostic criteria, management, treatment, and prognosis will be discussed. In particular, the evolution of radiographic changes with treatment in one patient will be assessed (Case 2). Read More

Authors:  Parikh Ashishkumar , Luo Yu , Spottswood Stephanie

Keywords:  hypophosphatasia, skeletal dysplasia, phosphate, hypophosphatemia, Bowdler

Miyazaki Osamu,  Sawai Hideaki,  Yamada Takahiro,  Murotsuki Jun,  Horiuchi Tetsuya,  Nishimura Gen

Final Pr. ID: Poster #: SCI-014

Fetal CT has almost the same utility as a postnatal skeletal survey. Despite this benefit, the associated radiation exposure is disadvantageous and radiation dose reduction is mandatory. It is however impossible to measure the actual radiation dose to the fetus directly. Several previous reports have described the CT dose index (CTDI) volume and dose length product (DLP) as representing an imagined fetal dose. The actual fetal radiation dose needs to be confirmed using a phantom that practically corresponds to a pregnant woman. Read More

Authors:  Miyazaki Osamu , Sawai Hideaki , Yamada Takahiro , Murotsuki Jun , Horiuchi Tetsuya , Nishimura Gen

Keywords:  skeletal dysplasia, fetal CT, radiation dose

Handa Atsuhiko,  Nishimura Gen

Final Pr. ID: Poster #: EDU-034

Skeletal dysplasias encompass a heterogeneous group of over 400 disorders. They are individually rare, but collectively common with an approximate incidence of 1/5000; thus, radiologists occasionally encounter skeletal dysplasias in daily practice. However, many radiologists and trainees struggle with this topic because of the lack of proper resources.

A group of skeletal dysplasias that share similar radiological patterns has been grouped into a “skeletal dysplasia family” which generally have common pathogenesis. For example, a skeletal dysplasia family comprising mucopolysaccharidosis, oligosaccharidosis, and mucolipidosis all radiologically exhibit dysotosis multiplex, and all share an abnormality in lysosome dysfunction.

The beauty of this family concept is its simplicity and power. First, it allows a more systematic approach to the chaotic world of skeletal dysplasias – a stepwise approach, with the first step of general pattern recognition and categorization of a certain case into a certain family, and the second step of diagnosis based on more meticulous observations for subtle but distinctive radiological findings. Since major skeletal dysplasia families are limited in number, the radiologist can become familiar with their patterns. Second, radiographs can predict the presence of genetic mutations. Geneticists or pediatricians would appreciate the correct radiological diagnosis even in today’s genetics practice with advanced molecular techniques. Radiological diagnosis and genetics are complementary. Third, it may lead us to a more precise assessment of radiological findings. Shared findings among family members allow more accurate characterization of the severest end of the family which occasionally look similar to the one with different pathogenesis.

The purpose of this exhibit is to demonstrate the imaging characteristics of major skeletal dysplasia families and the stepwise approach to the diagnosis. We will review the classic and more recently established dysplasia families. In addition, we will review clinical and genetic features that help radiologists to participate in multidisciplinary care.

Introduction – Dysostosis multiplex family – FGFR3 (achondroplasia) family – COMP family – Type II collagenopathies – TRPV4 (metatropic dysplasia) family – Skeletal ribosomopathies – DTDST (diastrophic dysplasia) family – Linkeropathies – Filaminopathies A and B – Punctata group – Skeletal ciliopathies – Osteogenesis imperfecta group Read More

Authors:  Handa Atsuhiko , Nishimura Gen

Keywords:  Skeletal dysplasia