Format

Send to

Choose Destination
See comment in PubMed Commons below
Bone. 2006 Feb;38(2):273-9. Epub 2005 Sep 30.

Automated registration of hip and spine for longitudinal QCT studies: integration with 3D densitometric and structural analysis.

Author information

  • 1Department of Radiology, University of California at San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94143-0946, USA. Wenjun.Li@radiology.ucsf.edu

Abstract

To eliminate user interaction in longitudinal quantitative computed tomography (QCT) measurements of bone mineral density (BMD) and geometry, we have developed and optimized an automated registration algorithm for QCT images of the hip and spine and integrated it with a previously developed 3D densitometric and structural analysis program. With registration, the follow-up images are automatically aligned with respect to the baseline scans, and the bone quantification of the aligned follow-up scan is initiated based on the bone morphometric features defined on the baseline scan. To validate the algorithm, we analyzed 20 pairs of repeat QCT images (10 hip pairs and 10 spine pairs) acquired on a modern multi-slice CT scanner, with repositioning between each scan pair to simulate repeat visits. Bone measurements obtained with automatic registration achieved comparable or improved precision errors compared to those obtained by careful manual analysis of the follow-up scans. The algorithm we have developed was based on the mutual information approach, with simplex optimization under a multi-resolution scheme. The average registration time was 2.3 min for a hip pair and 1.1 min for a vertebra pair using a standard desktop computer. Based on the reduced user interaction, high degree of precision, and short execution time, this is a promising technique for monitoring therapy in patients and clinical trials.

PMID:
16199215
PMCID:
PMC1550383
DOI:
10.1016/j.bone.2005.08.014
[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Support Center