Feasibility of peripheral quantitative computed tomography (PQCT) for people with Parkinson’s

Background: People with Parkinson’s have a greater risk of low bone mineral density (BMD), and of falls, both contributing to an increased risk of fractures. Currently, dual-energy X-Ray absorptiometry (DXA) scanners are the clinical gold standard to measure areal BMD. However, such 2-dimensional measures are affected by bone size, and scans are not always practical for frail individuals. Peripheral quantitative computed tomography (pQCT) scans assess bone compartment specific density, composition, and geometry, providing volumetric measures independent of bone size.

Methods: We assessed the feasibility of conducting pQCT scans of the lower-leg and forearm in a Parkinson’s cohort using the StratecXCT2000L. Three sites were imaged in the lower-leg, and two were imaged in the forearm. Image quality was graded by the scan operator.

Results: In a Parkinson’s cohort (n = 143) with mean age 74.7 years (SD = 7.91), 29.4% clinical frailty scale 5 or more, 122 lower-leg and 131 forearm scans were completed. Difficulty positioning participants, and hardware/software issues were the main reasons why leg and arm scans were not completed respectively. Of the completed scans over 98% of all slices obtained from the leg, and 93% of slices from the arm were of sufficient quality for analysis.

Conclusion: We have shown that pQCT scans are feasible in a Parkinson’s cohort including older adults living with frailty. Tremor or dyskinesia rarely resulted in severe movement artefacts, and most scans were of sufficient quality for analysis. Using a scanner with a larger aperture would increase the number of scans at the leg.