The Lodox Statscan has won several innovation and design awards which bear testimony to the creative and innovative thinking that goes on in the company. However, not only the engineers at Lodox like exploring and pushing the boundaries; the end-users of the scanners have also been thinking outside the box and looking for novel ways to exploit the features the Lodox scanners have to offer. For example, in the medical field the scanner was shown to be useful in arteriography and was suitable as an alternative means of imaging ventriculoperitoneal shunts.
Three recent online articles (University of Pretoria, News24, Idaho State Journal) took up the story of Dr Kyra Stull who recently graduated with a PhD from Pretoria University. Dr Stull has devised a new method that is useful for determining the age and sex of sub-adult (younger than 12 years) skeletal remains, a vital tool in forensic anthropology.
This is not the first time that a Lodox scanner has been used in forensic anthropology. Skeletal and mummified remains from Limpopo province in South Africa were imaged. Various other studies of bones using the Lodox scanner have been conducted over the years at the University of Cape Town, whether to determine the validity of previous methods for determining age, or whether to look for disease patterns in early populations in the Western Cape.
The particular problems related to determining the age at death of a child’s remains is that there is a lot of variability in growth patterns in children. Previous methods measuring the length of bones relied mainly on reference material dating from the 1800s, using North American and European Caucasian antiquated skeleton collections. However, these methods relied on small sample sizes of a relatively homogeneous population, and ignored the changes in stature and build of modern children (they are generally taller and larger), as well as ethnic, cultural and socio-economic differences.
Dr Stull has compiled the world’s largest known image database of children’s long bones. These are Lodox X-ray images from Red Cross War Memorial Children’s Hospital and from Salt River Forensic Pathology Services. From various measurements on the bones statistical/mathematical regression calculations can be done to estimate the age of a long bone.
X-ray images from hospitals and mortuaries would be a very useful resource for such a tool. However, regular X-ray machines tend to distort the image, making measurements from the images problematic. In addition, an X-ray image is a projection, much like a shadow of an object (in this case the bones) cast onto the detector. The further away the object is from the detector (object to image distance OID), the larger the “shadow” (Figure 2). Therefore, unless the geometry of the X-ray device is known, or if a reference object with known dimensions is present in the image, it is impossible to determine true sizes from the X-ray image. These problems are eliminated when using a Lodox scanner. The scanner produces a very thin fan beam which does not distort the image in the scan direction. Therefore, measurements in the scan direction are true lengths on the X-ray image. In fact, 97% of measurements on the Lodox X-ray image are within ± 2 mm of the true length and 85% are within ± 1 mm. The viewing software that comes with the Lodox scanner allows for measurements to be taken directly on the digital image.
When the first low-dose scanner was produced by De Beers to prevent the theft of diamonds, nobody imagined how this technology would evolve and find a use, first in the trauma unit, then in forensic pathology mortuaries, and now in forensic anthropology. Watch this space; we are certain more novel uses will be found to exploit the characteristics of this unique low-dose X-ray scanner.