PMCID: PMC5127038 DOI: 10.1186/s12969-016-0123-3
BACKGROUND: Dystrophic calcifications may occur in patients with J uvenile Idiopathic Inflammatory Myopathy (JIIM) as well as other connective tissue and metabolic diseases, but a reliable method of measuring the volume of these calcifications has not been established. The purpose of this study is to determine the feasibility of low dose, limited slice, Computed Tomography (CT) to measure objectively in-situ calcification volumes in patients with JIIM over time.
METHODS: Ten JIIM patients (eight JDM, two Overlap) with calcifications were prospectively recruited over a 2-year period to undergo two limited, low dose, four-slice CT scans. Calculation of the volume of calcifications used a CT post processing workstation. Additional patient data included: Disease Activity Scores (DAS), Childhood Myositis Assessment Scale (CMAS), myositis specific antibodies (MSA), and the TNFα-308 promoter region A/G polymorphism. Statistical analysis utilized the Pearson correlation coefficient, the paired t-test and descriptive statistics.
RESULTS: Ten JIIM, mean age 14.54 ± 4.54 years, had a duration of untreated disease of 8.68 ± 5.65 months MSA status: U1RNP (1), PM-Scl (1), Ro (1, 4 indeterminate), p155/140 (2), MJ (3), Mi-2 indeterminate (1), negative (3). 4/8 JDM (50%) were TNF-α-308 A+. Overall, the calcification volumes tended to decrease from the first to the second CT study by 0.5 cm
CONCLUSION: We conclude: 1) the limited low dose CT technique provides objective data about volume of the calcifications in JIIM; 2) measuring the volume of calcifications in an extremity is associated with minimal radiation exposure; 3) This method may be useful to evaluate the efficacy of therapies for JIIM dystrophic calcification.
Pediatr Rheumatol Online J
Adolescent; Calcinosis; Child; Feasibility Studies; Female; Humans; Male; Myositis; Pilot Projects; Radiation Dosage; Tomography, X-Ray Computed; Young Adult
Calcification; Calcification volume; Computed Tomography (CT); Juvenile idiopathic inflammatory myopathy; Overlap syndrome
Ibarra, M., Rigsby, C., Morgan, G. A., Sammet, C. L., Huang, C., Xu, D., Targoff, I. N., Pachman, L. M. Monitoring change in volume of calcifications in juvenile idiopathic inflammatory myopathy: a pilot study using low dose computed tomography. Pediatr Rheumatol Online J 14, 64-64 (2016).