Introduction
While reduced growth, as compared with population standards (usually below the 5th percentile) can occur at any time during childhood, a retardation of growth during puberty can have life long reprecussions. We had previousy defined the onset of the pubertal growth spurt, for a discrete population group, as the age at which the male bone mass surpasses that of the female. We pursued this by a review of cases, to determine what contributions imaging studies can make to problem cases.
Methods
Pediatric imaging cases were reviewed, to determine their role and contributions to endocrine evaluations of growth problems. More specifically, we began with bone densitometry studies because of the minimal radiation dose and ability to detect reduced bone mineral content. Bone scans (obtained with Tc-99m-diphosphonate) were examined to look at activity in the osseous growth centers. Were the osseous centers activity compatible with the reported age of the child (since each center "appears" and "disappears" at a specific age range)?
Results
Reduced bone density was uncommen in the younger children in our population, but was found in some teen agers, likely related to poor diet as well as anorexia or bulimia. Radiotracer bone scans revealed reduced osseous growth center activity (usually focal) in cases of trauma, or after therapy of malignancies. "Metabolic closure" of a site, prior to the age-appropriate time, indicated little opportunity for further growth of the affected bone. These data can often be supplemented with imaging information as to the size or function of internal organs.
Conclusions
Endocrine data on changes during the pubertal period can, in problem cases of failure to grow (or growth asymmetrically), be supplemented by imaging studies. The largest area for contributions may be in the osseous system. Bone density evaluation is rapid, accurate and of low radiation exposure. Particular utilization may be in teen agers with eating problems. Bone scans, with the Tc-99m-diphosphonates, can reveal whether the osseous growth centers are still metabolically active (and are "age appropriate").
References
Spencer PJ, Spencer RP: Growth, Development & Aging, in press.