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CT-3D MERGE fusion imaging improves image quality compared with CT and 3D MERGE in patients with lumbar disc
Hongyi Li1, Hailong Liu1, Mengqiang Xiao1
1Department of Radiology, Guangdong Provincial Hospital of Chinese Medicine, Zhuhai, China.
Background:
CT-routine MRI fusion imaging has recently become available to evaluate spinal anatomy before surgery. Due to the 3-5 mm slice thickness and non-isotropic of routine MRI sequence, the CT-routine MRI fusion imaging is not good. The MRI multiple recalled gradient echo (MERGE) sequence is potentially useful in diagnosis of lumbar degeneration disease due to the better nerve roots visualization, 1 mm slice thickness and its isotropy.
Purpose:
The present study aimed to evaluate the image quality of CT-3D MERGE fusion images compared with CT and 3D MERGE images in patients with lumbar disc herniation.
Methods:
Fifty-nine patients with lumbar disc herniation who underwent both lumbar CT and MRI including 3D-MERGE and routine lumbar MRI sequences were evaluated. All CT, 3D MERGE and CT-3D MERGE fusion images were separately assessed by two radiologists using five-point Likert scoring method based on five aspects: display of bony structure, intervertebral discs, nerve roots, overall anatomical details and image artifacts. Furthermore, two observers documented the sacral slope (SS), L4/5 intervertebral space heights (ISH), width and height of L4/5 intervertebral foramen (FW and FH) on CT and CT-MERGE fusion images.
Results:
There was insufficient evidence to show a difference in bony structure score between CT and CT-3D MERGE fusion images (p = 0.22), but it was significantly higher than that of MERGE (p < 0.001). The scores of intervertebral discs and nerve roots between MERGE and fusion images were not statistically different (p = 0.19 and 0.88), which were higher than CT (all p < 0.001). The overall anatomical detail score of fusion imaging was higher than CT and MERGE (p < 0.001). No significant difference of image artifacts score was found among CT, MERGE and fusion images (p = 0.47). There was no significant difference in SS, ISH, FW, FH values between CT and fusion images (all p > 0.05).
Conclusion:
CT-3D MERGE fusion images exhibit superior image quality to both CT and 3D MERGE for the simultaneous observation of bony structures, intervertebral discs, and nerve roots.
Insights
CT-3D MERGE fusion imaging offers superior visualization of spinal anatomy, including bony structures, discs, and nerve roots, compared to standard CT and routine MRI. This advanced technique enhances diagnostic accuracy for lumbar disc herniation.
Area of Science:
- Radiology
- Medical Imaging
- Spinal Diagnostics
Background:
- Routine MRI sequences have limitations (3-5 mm slice thickness, non-isotropy) for pre-surgical spinal evaluation.
- The MRI multiple recalled gradient echo (MERGE) sequence shows promise for lumbar degeneration due to better nerve root visualization and higher resolution (1 mm, isotropic).
Purpose of the Study:
- To compare the image quality of CT-3D MERGE fusion images against standard CT and 3D MERGE images.
- To evaluate the efficacy of CT-3D MERGE fusion in patients with lumbar disc herniation.
Main Methods:
- Evaluated 59 patients with lumbar disc herniation who underwent CT and MRI (3D-MERGE and routine).
- Radiologists assessed CT, 3D MERGE, and CT-3D MERGE fusion images using a 5-point Likert scale for bony structures, discs, nerve roots, anatomical detail, and artifacts.
- Measured sacral slope, intervertebral space heights, and intervertebral foramen dimensions on CT and CT-MERGE images.
Main Results:
- CT-3D MERGE fusion showed significantly higher bony structure scores than MERGE (p < 0.001) but not standard CT (p = 0.22).
- Intervertebral disc and nerve root scores were comparable between MERGE and fusion images (p > 0.19) but superior to standard CT (p < 0.001).
- Overall anatomical detail was significantly better on fusion images compared to CT and MERGE (p < 0.001); artifact levels were similar across all modalities.
Conclusions:
- CT-3D MERGE fusion imaging provides superior image quality for simultaneously visualizing bony structures, intervertebral discs, and nerve roots.
- This technique enhances the evaluation of spinal anatomy in patients with lumbar disc herniation.
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