MEASUREMENT OF SPINAL DEFORMITIES USING 
STEREOPHOTOGRAMMETRY 
K Jones 
School of Planning, Landscape Architecture and Surveying 
Queensland University of Technology 
BRISBANE QUEENSLAND 4000 
G N Askin, W E Ryan, C Natalie and A D Porter 
Mater Misericordiae Hospital 
SOUTH BRISBANE QUEENSLAND 4101 
AUSTRALIA 
Commission V, Working Group 5 
KEY WORDS: 
Medical Imaging. 
Close Range, Measurement, 
Medicine, Stereoscopic Acquisition, 
Biostereometrics, 
ABSTRACT: Idiopathic scoliosis is primarily a cosmetic deformity comprising a scoliosis (lateral bend) and 
a rib hump posteriorly related to twisting of the spine as well as disordered rib growth. The authors were 
involved in a project looking at the use of surface shape for the assessment and monitoring of scoliosis. 
The aims of the project were to measure back shape and to show the reproducibility of the measurement. 
This paper describes the photogrammetric acquisition, restitution and measurement aspects of the project 
and outlines the results obtained and current directions being followed. 
1. INTRODUCTION 
1.1 Background 
Idiopathic scoliosis is primarily a cosmetic deformity 
comprising a scoliosis (lateral bend) and a rib 
hump posteriorly related to twisting of the spine as 
well as disordered rib growth. It typically occurs in 
pubescent girls and may progress during 
adolescent growth phase or early afterwards. Only 
in severe deformities does it interfere with 
respiratory and cardiac function. 
The management of idiopathic scoliosis is twofold. 
Firstly, to identify those curves which are 
progressive, and secondly to surgically recreate the 
optimal cosmetic trunk appearance and prevent 
further progression in those patients whose 
deformity exceeds acceptable limits. 
Identification of the condition is largely through 
school health screening programmes and is based 
on a crude assessment of rib hump. Further 
assessment and monitoring are both clinical (using 
instruments such as spirit level) and radiological 
(using X-rays to measure the lateral deviation of 
the spine). However, the radiographic parameters 
do not necessarily correlate with actual rib 
deformity and correction of the scoliosis by surgery 
may not correct rib hump. 
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Monitoring the condition is both clinical and 
radiological and continues until after skeletal 
maturity. However, multiple radiographic 
examinations in this age group of girls is not 
considered desirable. While not the only method 
available, photogrammetry is a non contact, non 
invasive method of measuring the three 
dimensional back shape of patients and offers the 
possibility of reducing or minimising radiographic 
examinations. 
1.2 Experimental Procedure 
A series of stereoscopic photographs were taken of 
a group of twelve patients. This series consisted of 
an initial set of three photographs at a single sitting 
where the patient was photographed in a frame, 
then removed from the frame for a period of time, 
repositioned and rephotographed. Each set of 
photographs was followed by the radiographic 
examination normally used in the clinic to allow 
later comparison of back topography with X-ray 
parameters. This initial set of stereophotographs 
was used to determine the reproducibility of the 
technique. Subsequent series of stereophotographs 
was taken at 3 and 9 months. The second series 
will be used to determine whether any progression 
in the scoliotic curves can be detected using 
photogrammetry, and to develop guidelines for 
further radiological investigation. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B5. Vienna 1996 
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