Lumbar diskography

The correlation between the lumbar disc MRI high-intensity zone and discogenic low back pain: a systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the correlation between the MRI high-intensity zone (HIZ) and the pathogenesis of discogenic low back pain.

METHODS

Literature from PubMed, EMBASE, Cochrane Library, Science Direct, China Knowledge Network, Wanfang Database, and China Biomedical Literature Database was searched until August 2023. Cohort studies including patients with low back pain who underwent lumbar spine MRI and discography, as well as the results evaluating the correlation between HIZ and discography for morphological changes in the disc and pain replication phenomena, were included in the analysis. The literature that met the inclusion criteria was screened, and the methodological quality of the included studies was evaluated. Meta-analysis of the extracted data was performed by using RevMan 5.1.1.

RESULTS

In total, 28 reports were included in this meta-analysis. There was a statistically significant correlation between a positive HIZ and abnormal disc morphology in discography (OR 28.15, 95% CI [7.38, 107.46], p < 0.00001). Patients with HIZ-positive discs had a significantly higher incidence of consistent pain (71.0%, 969/1365) than those with HIZ-negative imaging (29.0%, 1314/4524) (OR 7.71, 95% CI [5.29, 11.23], p < 0.00001).Segments that were HIZ-positive and had abnormal disc morphology had a higher incidence of consistent pain (86.1%, 230/267) than HIZ-negative subjects (32.2%, 75/233) (OR 14.09, 95% CI [2.12, 93.48], p = 0.006).

CONCLUSION

A positive MRI T2-weighted image of the lumbar disc with HIZ indicates disc degeneration. In addition, HIZ may be a specific indicator for the physical diagnosis of discogenic low back pain. A more advanced degree of disc degeneration on the basis of HIZ positivity corresponded to a greater probability of discography-induced consistent pain, whereas the degree of disc degeneration on the basis of HIZ negativity was less correlated with contrast-induced consistent pain.

Differentiating lumbar disc protrusions, disc bulges, and discs with normal contour but abnormal signal intensity. Magnetic resonance imaging with discographic correlations

STUDY DESIGN

Independent evaluation by two observers of 132 lumbar discs in 45 patients with chronic low back pain investigated by both magnetic resonance imaging and discography.

OBJECTIVES

To assess some of the fundamental differences between lumbar disc protrusions, disc bulges, and discs with normal contour but abnormal signal intensity on T2-weighted magnetic resonance images.

SUMMARY OF BACKGROUND DATA

Moderate interobserver agreement has been reported when the morphologic terms normal, bulge, protrusion, and extrusion are used. The validity of this nomenclature remains unknown.

METHODS

Discs were evaluated on magnetic resonance images for central and peripheral signal characteristics, height, contour, and nerve root compression. Discograms were classified according to degrees of disc degeneration, disruption, and pain reproduction.

RESULTS

Loss of intervertebral height or abnormal signal intensity on magnetic resonance imagery was significantly associated with disc disruptions extending into or beyond the outer anulus on discograms. All 23 protrusions (100%) and 12 of 15 disc bulges (80%) were associated with Stage 2 or 3 anular disruptions and, in most instances, similar or exact reproduction of pain during disc injection. There was no significant difference between disc protrusions, disc bulges, and discs with normal contour but abnormal signal, with respect to degree of disc degeneration, extent of disruptions, or presence of discogenic pain.

CONCLUSIONS

In patients with chronic low back pain, loss of disc height or abnormal signal intensity is highly predictive of symptomatic tears extending into or beyond the outer anulus. Disc bulges and disc protrusions do not represent discs with significantly different internal architecture, based on the findings of discography, and are no more suggestive of symptomatic tears than discs showing normal contour but decreased height or abnormal signal intensity.

The role of radiology in percutaneous laser disc decompression

Diagnostic imaging has always played a key role in the evaluation of patients with suspected lumbar disc herniation. With the development of percutaneous laser disc decompression (PLDD), radiology is now equally important in its treatment. All physicians involved with the PLDD candidate must be familiar with the imaging techniques unique to this procedure to ensure a successful outcome. The following review is based on the cumulative experience gained in performing over 200 PLDD procedures. It discusses the function of diagnostic radiology in all facets of PLDD including patient selection, intraoperative imaging, postoperative evaluation, and analysis of complications. Fundamental radiologic concepts that apply to PLDD are explained and protocols suggested to optimize results and avoid complications.

Radiological considerations: patient selection for percutaneous laser disc decompression

Percutaneous laser disc decompression (PLDD) is an effective method of treating the lumbar herniated nucleus pulposis (HNP) that is both contained by the annular/posterior longitudinal ligament (PLL) complex and connected to the parent disc of origin. Not all radiological studies have the same ability to diagnose this specific type of herniation and therefore are not equally useful in the preoperative evaluation of the PLDD candidate. Ninety PLDD treated patients were retrospectively reviewed to determine which of the four most commonly performed lumbar imaging exams, when abnormal, correlated with a successful outcome. Overall MacNab criteria improvement occurred in 73.3% of PLDD-treated patients. An abnormal CT discogram correlated with PLDD success in all patients treated (100%). An abnormal MRI, CT, or myelogram correlated with success in 75% or less of patients treated. The theoretical reasons for the superiority of CT discography are discussed and the diagnostic potential of all major lumbar imaging modalities is reviewed. A diagnostic decision scheme for the evaluation of the prospective PLDD patient is presented.

Radiological considerations: percutaneous laser disc decompression

Diagnostic radiology is an integral part of percutaneous laser disc decompression (PLDD). All physicians involved in PLDD patient selection and treatment must be familiar with the imaging techniques unique to this procedure to ensure a successful outcome. The following review is based on the cumulative experience gained in performing over 150 PLDD procedures. It discusses the function of diagnostic radiology in all facets of PLDD including patient selection, intraoperative imaging, postoperative evaluation, and analysis of complications. Fundamental radiologic concepts that apply to PLDD are explained and protocols suggested to optimize results and avoid complications.