Background Both CT and MRI are widely known to be important tools in diagnosing spinal disorders. However, even when three-dimensional data are collected, images are often presented in two dimensions and in monochrome. Furthermore, CT and MRI represent different types of information, and it is very difficult for doctors to mentally fuse these images. We have been working to overcome these challenges, and reported the first 3-D MRI/CT fusion images1,2. We present herein the cervical nerve roots (two cases of cervical spondylotic amyotrophy) in which noteworthy finding were observed about cervical nerve roots by using this technique.
Objectives There are many patients suffering from cervical radiculopathy or muscular atrophy of upper extremity due to C5, 6, 7 nerve root disorders. We have produced virtual anatomy of C5, 6 and 7 nerve roots to evaluate the pathological state and courses of nerve roots.
Methods We used an Asteion 4® 4-row CT unit (TOSHIBA, Tochigi, Japan) and an Echelon Vega® 1.5-T MRI unit (HITACHI, Tokyo, Japan). We combined 3-D CT images of bone construction with 3-D MRI of both neural architecture (spinal cord and nerve roots) using Synapse Vincent® workstation software (FUJIFILM, Tokyo, Japan). The method for producing images was as follows. First, DICOM data from CT and MRI were transmitted to the workstation. Next, the Multivolume application on the workstation was used to create a 3-D architecture from the respective CT and MRI data in the same space by the volume-rendering method. The position and rotation tool was used for sagittal, axial, and coronal positions in the respective virtual images, and adjusted manually. Cervical nerve roots were mapped and segmented, then color was applied for visualization.
Results We could evaluated unambiguous, 3-D confirmation of the pathological state and courses of nerve roots (C5, 6, 7) of CSA cases, both inside and outside the foraminal arch of the spine, as well as the locations with bony spurs. Positional relationships between intervertebral discs, bony spurs and nerve roots/spinal cord could also be depicted. We could observe the entire cervical spine in any direction at a glance. A total of 5-8 h was required to produce 3-D fusion imaging.
Conclusions This is a groundbreaking method that enables both bone and cervical roots to be viewed simultaneously, and an even greater merit of these images is that they are produced using minimally invasive scanning methods without the use of contrast media.
It is vitally important to obtain MRI data to produce fusion images, and there are numerous reasons for the poor results of MRI to date. Why is it so difficult to obtain clear MR images of the cervical spine? We have researched the following conditions for getting best image, that is, MRI hardware, MRI operation, and scan time. We show the latest technical data for MRI driving.
There may well be spinal pathology that are only detected after the start of spinal surgery. Nonetheless, if it were possible to demonstrate that the patient’s detailed anatomy could not be seen satisfactorily in preoperative images, it may also be possible to better interpret preoperative images. Virtual images have thus enabled the visualization of previously inaccessible anatomical locations and depiction in detailed images.
Yamanaka Y, 3-D MRI/CT fusion imaging of the lumbar spine. Skeletal Radiol 2010
Kamogawa J, Virtual anatomy of spinal disorders by 3-D MRI/CT fusion imaging. In the book “Scoliosis”, InTech, 2012, in press.
Disclosure of Interest None Declared