Myelography using flat panel volumetric computed tomography: a comparative study in patients with lumbar spinal stenosis.

STUDY DESIGN: The technical feasibility of flat panel volumetric computed tomography (FPVCT) for lumbar myelographic imaging was evaluated in 20 patients and compared with multislice computed tomography (MSCT).

OBJECTIVE: The purpose of this study was to determine the feasibility and sensitivity of FPVCT for myelographic imaging in lumbar spinal stenosis.

SUMMARY AND BACKGROUND DATA: In the diagnosis of spinal stenosis, myelography and myelo-computed tomography (PCT) have been performed routinely for nearly 30 years. Rotational angiography is a new technique initially developed to visualize vessels but also allowing multiplanar reconstructed (MPR) CT images. The spatial resolution of FPCVT is even higher than in current MSCT. To date, this technique has not been evaluated for use in myelography.

METHODS: In 20 patients referred for CT for evaluation of low back pain, lumbar myelography was performed on a biplane angiography system equipped with flat panel detectors. FPVCT was provided from a volume data set out of a rotational acquisition and compared with MSCT performed on a 4-slice CT scanner. Hereby, for a total of 100 disc levels (range from L1-L2 to L5-S1), the narrowest dural cross-sectional diameter (D-CSD) and the dural cross-sectional area (D-CSA) referred to MSCT and FPVCT were calculated.

RESULTS: Mean D-CSD and C-CSA for all disc levels as measured by MSCT was 9.26 +/- 3.0 mm and 63.2 +/- 10.8 mm, respectively. Compared with D-CSD and C-CSA measured by FPVCT, there was no statistically significant difference (9.48 +/- 2.9 mm and 64.7 +/- 11.2 mm, respectively; P > 0.89). The most pronounced lumbar spinal stenosis was seen on L4/5 level with D-CSD of 6.6 +/- 3.6 mm and 6.8 +/- 3.2 mm and D-CSA of 53.7 +/- 14.7 mm and 55.0 +/- 14.3 mm, respectively.

CONCLUSION: In all patients, the diagnostic quality of the reconstructed FPVCT slice images is comparable to those acquired by MSCT. Using FPVCT, radiographic myelography and postmyelographic computed tomography can be performed with less radiation in a single session at the same imaging system.