Functional evaluation of the lumbar spine with axial loaded computed tomography (AL-CT) and cine AL-CT

This study reports a personal experience in the functional study of the lumbar spine with original diagnostic techniques called Axial Loaded Computed Tomography (AL-CT) and Cine AL-CT, based on the use of the Axial Loader, a device that develops a variable and reproducible axial load in a supine patient during computed tomography or magnetic resonance investigation(3,4). We built a non ferromagnetic, X-ray transparent bed (the Axial Loader), with double blocking rests for shoulders and feet, that can be used during CT and MR spine studies. The inferior block is a platform that moves continuously in a longitudinal direction, with a micrometric mechanism. A dynamometer placed between the inferior platform and the patient's feet can measure the load applied. We studied 75 patients, with a clinical and diagnostic suspicion of lumbar spine instability. The examinations were performed on a conventional CT unit (GE Sytec 3000, General Electric, Milwaukee) with a ''volumetric'' approach to the lumbar spine. In conclusion, AL-CT and Cine AL-CT is currently the only diagnostic modality that can give dynamic information on the differents UFSs in all their components in one mildy invasive, easily reproducible diagnostic examination.