An integrative framework for 3D cobb angle measurement on CT images.
Measuring the Cobb angle on computed tomography (CT) images remains a challenging but requisite task for clinical diagnoses of scoliosis. Traditionally, clinical practitioners resort to manual demarcation, but this approach is inefficient and subjective. Most of the existing computerized algorithms are two-dimensional (2D) and incapable of multi-angle calibration.



A novel integrative framework based on curvature features and geometric constraints is proposed to measure three-dimensional (3D)Cobb angles on CT images. This framework enables Cobb angle estimation in stereo and accomplishes the synchronous computation of the Cobb angle in three imaging planes. The whole system was quantitatively evaluated on 22 spine models obtained from the clinic.



The results demonstrate that the integrative framework performs well in clinical Lenke classification and outperforms both the traditional manual method and the 2D digital method as evidenced by high intra-observer and inter-observer reliability (ICC>0.94, SEM 0.9°-1.2° for intra-observer, ICC>0.94, SEM 0.8°-1.2° for inter-observer). This 3D framework is also robust across different models (SE<3°).



The new integrative framework is able to measure the Cobb angles in three imaging planes simultaneously and is therefore clinically advantageous.
Hefei University of Technology, Hefei, China.
Xing
X
Huo
Hefei University of Technology, Hefei, China.
Jie Qing
JQ
Tan
The Second Hospital of Anhui Medical University, Hefei, China.
Jun
J
Qian
The Second Hospital of Anhui Medical University, Hefei, China.
Li
L
Cheng
The Second Hospital of Anhui Medical University, Hefei, China. Electronic address: jyh_2016@hotmail.com.
Jue Hua
JH
Jing
Hefei University of Technology, Hefei, China.
Kun
K
Shao
Hefei University of Technology, Hefei, China.
Bing Nan
BN
Li
D000465:Algorithms; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D015588:Observer Variation; D010363:Pattern Recognition, Automated / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012600:Scoliosis / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
3D cobb angle measurement; 3D spinal model; Best-fit plane; Computed tomography; Curvature feature