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Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI.

Yi JS, Cha JG, Han JK, Kim HJ - Korean J Radiol (2015)

Bottom Line: Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial.MDCT tended to underestimate the extent of herniated disc lesions compared with MRI.MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon 420-767, Korea.

ABSTRACT

Objective: To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI).

Materials and methods: Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI.

Results: The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI.

Conclusion: Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

No MeSH data available.


Related in: MedlinePlus

Schematic of seven virtual segments of C-spine for evaluation of epicenter and number of involved segments of herniated disc materials.Two imaginary lines (*) are drawn by tracing inner margin of bilateral pedicles, and additional four lines that divide inter-pedicular space evenly are drawn. Additionally, another two lines that divide same space at lateral aspect of lines drawn along inner margin of pedicles are drawn. As result, eight virtual lines are drawn on posterior aspect of body of cervical spine, and seven segments are created.
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Figure 2: Schematic of seven virtual segments of C-spine for evaluation of epicenter and number of involved segments of herniated disc materials.Two imaginary lines (*) are drawn by tracing inner margin of bilateral pedicles, and additional four lines that divide inter-pedicular space evenly are drawn. Additionally, another two lines that divide same space at lateral aspect of lines drawn along inner margin of pedicles are drawn. As result, eight virtual lines are drawn on posterior aspect of body of cervical spine, and seven segments are created.

Mentions: After independent evaluation, the three readers formed consensus interpretations on of the disc morphology on axial and sagittal MDCT images and MRI, and the extent of agreement between the two techniques was determined by reference to these consensus interpretations. Herniated discs (protrusion and extrusion) were selected from 255 disc levels at which the three readers agreed herniation was evident on both MDCT and MRI (Fig. 1). Also, an interpretation agreed upon by two readers was considered to be a consensus. If there were differences in disc morphological evaluation among the three readers, the disc levels were re-evaluated by all readers to attain a consensus interpretation. To evaluate the number of involved segments (NIS) and epicenter of herniated disc materials, the locations of the NIS and epicenter were recorded by two reviewers. Two imaginary lines were drawn by tracing the inner margin of the bilateral pedicles, and an additional four lines that divided the inter-pedicular space evenly were drawn. Furthermore, another two lines that also divided the same space at the lateral aspect of the lines drawn along the inner margin of the pedicles were drawn. As a result, eight virtual lines were drawn on the posterior aspect of the body of the cervical spine, and seven segments were created. Figure 2 shows a schematic of the seven segments. Next, the readers were asked to select the segment that showed the maximal extent of posterior herniation (Fig. 3). For the assessment of inter-modality agreement in terms of the NIS and epicenter of the herniated disc materials, 58 disc levels from 36 patients were selected. Twenty-three patients were males (mean age, 52.5 years; range, 17-77 years), and 13 were females (mean age, 51.23 years; range, 26-76 years); the mean age of all patients was 52.0 years (range, 17-77 years) (Fig. 1).


Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI.

Yi JS, Cha JG, Han JK, Kim HJ - Korean J Radiol (2015)

Schematic of seven virtual segments of C-spine for evaluation of epicenter and number of involved segments of herniated disc materials.Two imaginary lines (*) are drawn by tracing inner margin of bilateral pedicles, and additional four lines that divide inter-pedicular space evenly are drawn. Additionally, another two lines that divide same space at lateral aspect of lines drawn along inner margin of pedicles are drawn. As result, eight virtual lines are drawn on posterior aspect of body of cervical spine, and seven segments are created.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4499554&req=5

Figure 2: Schematic of seven virtual segments of C-spine for evaluation of epicenter and number of involved segments of herniated disc materials.Two imaginary lines (*) are drawn by tracing inner margin of bilateral pedicles, and additional four lines that divide inter-pedicular space evenly are drawn. Additionally, another two lines that divide same space at lateral aspect of lines drawn along inner margin of pedicles are drawn. As result, eight virtual lines are drawn on posterior aspect of body of cervical spine, and seven segments are created.
Mentions: After independent evaluation, the three readers formed consensus interpretations on of the disc morphology on axial and sagittal MDCT images and MRI, and the extent of agreement between the two techniques was determined by reference to these consensus interpretations. Herniated discs (protrusion and extrusion) were selected from 255 disc levels at which the three readers agreed herniation was evident on both MDCT and MRI (Fig. 1). Also, an interpretation agreed upon by two readers was considered to be a consensus. If there were differences in disc morphological evaluation among the three readers, the disc levels were re-evaluated by all readers to attain a consensus interpretation. To evaluate the number of involved segments (NIS) and epicenter of herniated disc materials, the locations of the NIS and epicenter were recorded by two reviewers. Two imaginary lines were drawn by tracing the inner margin of the bilateral pedicles, and an additional four lines that divided the inter-pedicular space evenly were drawn. Furthermore, another two lines that also divided the same space at the lateral aspect of the lines drawn along the inner margin of the pedicles were drawn. As a result, eight virtual lines were drawn on the posterior aspect of the body of the cervical spine, and seven segments were created. Figure 2 shows a schematic of the seven segments. Next, the readers were asked to select the segment that showed the maximal extent of posterior herniation (Fig. 3). For the assessment of inter-modality agreement in terms of the NIS and epicenter of the herniated disc materials, 58 disc levels from 36 patients were selected. Twenty-three patients were males (mean age, 52.5 years; range, 17-77 years), and 13 were females (mean age, 51.23 years; range, 26-76 years); the mean age of all patients was 52.0 years (range, 17-77 years) (Fig. 1).

Bottom Line: Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial.MDCT tended to underestimate the extent of herniated disc lesions compared with MRI.MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon 420-767, Korea.

ABSTRACT

Objective: To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI).

Materials and methods: Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI.

Results: The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI.

Conclusion: Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

No MeSH data available.


Related in: MedlinePlus