A Novel Method to Measure the Sagittal Curvature in Spinal Deformities: The Reliability and Feasibility of 3-D Ultrasound Imaging

Timothy Tin Yan Lee, Wei Wei Jiang, Connie Lok Kan Cheng, Kelly Ka Lee Lai, Michael Kai Tsun To, René M. Castelein, Jason Pui Yin Cheung, Yong Ping Zheng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)


The objective of this study was to test the reliability of sagittal spinal curvature measurements using 3-D ultrasound in patients with adolescent idiopathic scoliosis (AIS). Ultrasound spinous process angle (USSPA) and ultrasound laminae angle (USLA) were measured on sagittal ultrasound images, while the Cobb angle (XCA) was measured on sagittal X-ray images. Intra-class correlation coefficients (ICC) for the intra- and inter-observer variability, linear regression analysis and Bland-Altman method, including mean absolute difference (MAD), were investigated to evaluate the reliability and validity of the two ultrasound angles compared with XCA. Excellent measurement reliabilities were demonstrated for both ultrasound angles (ICC ≥ 0.91). Moderate to good and significant linear correlations and good agreement were demonstrated between the ultrasound methods and XCA (Thoracic [R2 ≥ 0.574] / Lumbar [R2 ≥ 0.635]). No significant differences were found for the MADs between both corrected ultrasound angles and XCA. Sagittal ultrasound angles were demonstrated to be reliable for assessing sagittal curvature using spinous processes and laminae and to have good and significant correlations with XCAs. Since it is non-ionizing and relatively low cost, this method opens the possibility of providing frequent curve monitoring and evaluation, and screening for AIS patients, particularly based on sagittal profiles.

Original languageEnglish
Pages (from-to)2725-2735
Number of pages11
JournalUltrasound in Medicine and Biology
Issue number10
Publication statusPublished - Oct 2019


  • 3-D ultrasound
  • Sagittal
  • Scoliosis
  • Spinous processes

ASJC Scopus subject areas

  • Biophysics
  • Radiological and Ultrasound Technology
  • Acoustics and Ultrasonics

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