Intro By weighing the advantages and disadvantages, it will be possible for one to plan the investigations in the victims with symptoms ranging from low backache to, low backache with bladder involvement which will prove to be specific and cost effective instead of subjecting the victims to multiple investigations. With this in mind the present study comparative study conventional versus CT myelography in lumbar stenosis lesions was undertaken. AP diam. Less than 12 mm is considered canal stenosis , while less than 10 mm is considered absolute canal stenosis.
Materials and Methods: The present study included 80 patients who clinically presented with complains ranging from low backache to paraplegia, with or without bladder involvement and who were clinically considered to have compressive myelopathy. All the above patients were subjected to conventional myelographic  evaluation .Then the patient was subjected to CT scan evaluation of the lumbar spine by taking sequential sections on Spiral CT Scan unit  Results: On Con myelography, 31 patients were thought to have single disc involvement, but in 3 out of 31 were detected to have L5–S1 disc involvement on CTM which were missed on Con. myelo Conclusion : CT myelography proved to be far superior to conventional myelography as dimensions of the canal can be correctly measured.  Hypertrophy of ligamentum flavum can be assessed.  Involvement of apophyseal joints can be better noted.  Assessment of the epidural fat can be better, done on CT myelography than on conventional myelography.