Comparison of a new opposed phase imaging protocol to the standard conventional MRI protocol in demonstration of lumbar degenerative disc disease at 1.5T.
Date of Award
Master of Medicine (MMed)
Imaging and Diagnostic Radiology (East Africa)
Purpose: The purpose of the study was to compare diagnostic yield of a new Opposed Phase Imaging protocol [OPI] to the standard conventional MRI protocol [CONV] in demonstration of lumbar degenerative disc disease at 1.5T.
Materials and Methods: A total of 102 patients suspected of lumbar disc disease were examined using the two protocols. Images from both protocols were then analyzed independently by two radiologists. Category of disc disease[normal, bulge ,protrusion, extrusion] and anatomic clarity of spinal structures related to disc disease[nerve roots, osteophytes, modic changes and hemangiomas ] were assessed using a standard 4 point scoring scale [1=inadequate,2 =adequate,3=normal ,4=optimal.]
Comparison of the results from the two protocols was done using wilcoxons analysis, Mann Whitney test and the student paired t test.
Results: Of the 510 discs (in 102 patients) examined by OPI and conventional protocols, 488[96%,CI 93.93-97.45] had concordant diagnosis for disc disease and associated pathologies. Only 1% of the discordant disc lesions showed radiologically significant findings.
There was no statistically significant difference [P >0.05] among the two radiologists in the subjective scores given for the two protocols. OPI received similar scores to conventional protocol in optimally demonstrating osteophytes, modic changes and hemangiomas [p > 0.001].OPI however received significantly lesser scores [P< 0.001] for anatomic clarity of the discs and nerve roots.
The average imaging time for OPI protocol was 7 minutes which was significantly shorter [p <0.001, CI 7.07-7.19] than that of conventional protocol of 16 minutes.
Conclusion: OPI has comparable pick up rate for pathology in lumbar degenerative disc disease despite the fact that the new protocol gives less anatomic clarity compared to the conventional protocol for discs and nerve roots. The new protocol is adequate in demonstrating other spinal structures [modic changes, osteophytes and hemangiomas] related to degenerative disc disease.
OPI takes a significantly shorter imaging time and can therefore be an alternative time saver in imaging lumbar disc disease.
Magabe, P. C. (2010). Comparison of a new opposed phase imaging protocol to the standard conventional MRI protocol in demonstration of lumbar degenerative disc disease at 1.5T. (Unpublished master's dissertation). .
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