Carlos Andres Rojas MD, Presenter: Nothing to Disclose

Fawad Shaheen MD, Abstract Co-Author: Nothing to Disclose

Michael Edward Yokum MD, Abstract Co-Author: Nothing to Disclose

Eric J. Schmidlin MD, Abstract Co-Author: Nothing to Disclose

Carlos Rodrigo Martinez MD, Abstract Co-Author: Nothing to Disclose

Katie Jean Carpenter MD, Abstract Co-Author: Nothing to Disclose

Assessment of the pre-vertebral soft tissue (PVST) thickness in the pediatric population has been used in the evaluation of the cervical spine in traumatic and/or inflammatory processes. Previously reported data is based on analysis of lateral radiographs. The purpose of this study is to establish normal thickness of PVST in the pediatric population based on MDCT images.  

Cervical PVST thickness was retrospectively measured in 134 normal patients (0-16 yo) who underwent cervical spine MDCT with multi-planar reconstructions.The patients were divided by gender and age into four groups: 0-2 (n=23), 3-6 (n=30), 7-10 (n=33) and 11-16 (n=48). Measurements were performed in the mid-sagittal plane at the mid-vertebral body level parallel to the endplates from C1 to C7. The Mean, Range, SD and upper limit normal were calculated for each level. Established normal values were then compared to the accepted data on radiographs.

There is large variability in thickness of the PVST depending on age. The smallest upper limit normal values were found at C1-C3 levels, with the smallest standard deviation at C2 level. Below C4 the PVST enlarge due to the presence of the esophagus, and have large variability in thickness. The normal PVST thickness at C2-C3 levels was determined to be 9.8mm (0-2yo), 8.2mm (3-6yo), 8.5mm (7-10yo) and 8.0mm (11-16yo) compared to the accepted normal value of 6mm at C3 based on radiographs. No statistically significant difference was found between males and females.

The PVST thickness in children shows large variablity depending on age and is significantly thicker than in adults. The upper limit normal for the PVST C2-C3 levels on MDCT images are larger than the normal value suggested based on radiographs despite intrinsic magnification in radiography. These differences in the normal upper limit of normal are mainly due to the degree of cervical flexion/extension, inspiration/expiration and phase of swallowing, parameters controlled on radiographs but not routinely during MDCT acquisition.

Establishing upper limit of normal in the pediatric prevertebral soft tissue thickness on MDCT images.

Rojas, C, Shaheen, F, Yokum, M, Schmidlin, E, Martinez, C, Carpenter, K, Evaluation of the Normal Pediatric Prevertebral Soft Tissue Thickness on Multidetector Computed Tomography.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6019374.html