Severity of foraminal lumbar stenosis and the relation to clinical symptoms and response to periradicular infiltration-introduction of the "melting sign"

Correlation of Foraminal Parameters with Patient-Reported Outcomes in Patient with Degenerative Lumbar Foraminal Stenosis

The relationship between quantitative anatomic parameters in MRI and patient-reported outcomes (PROs) before and after surgery in degenerative lumbar foraminal stenosis remains unknown. We included 58 patients who underwent transforaminal lumbar interbody fusion (TLIF) for single-level degenerative disc disease with foraminal stenosis between February 2013 and June 2020. PROs were evaluated using the visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and EuroQol-5D (EQ-5D). The foraminal parameters assessed using preoperative MRI included foraminal height, posterior intervertebral disc height, superior and inferior foraminal width, and foraminal area. The correlation between foraminal parameters and PROs before operation, at 1 year follow-up, and change from baseline were assessed. The associations between the aforementioned parameters were examined using linear regression analysis. The analysis revealed that among these parameters, superior foraminal width was found to be significantly correlated with ODI and EQ-5D at the 1 year follow-up and with change in ODI and EQ-5D from baseline. The associations remained significant after adjustment for confounding factors including age, sex, body mass index, and duration of hospital stay. The results indicated that in degenerative lumbar foraminal stenosis, decreased superior foraminal width was associated with better improvement in disability and quality of life after TLIF.

The value of magnetic resonance imaging and computed tomography in the study of spinal disorders

Computed tomography (CT) and magnetic resonance imaging (MRI) have replaced conventional radiography in the study of many spinal conditions, it is essential to know when these techniques are indicated instead of or as complementary tests to radiography, which findings can be expected in different clinical settings, and their significance in the diagnosis of different spinal conditions. Proper use of CT and MRI in spinal disorders may facilitate diagnosis and management of spinal conditions. An adequate clinical approach, a good understanding of the pathological manifestations demonstrated by these imaging techniques and a comprehensive report based on a universally accepted nomenclature represent the indispensable tools to improve the diagnostic approach and the decision-making process in patients with spinal pain. Several guidelines are available to assist clinicians in ordering appropriate imaging techniques to achieve an accurate diagnosis and to ensure appropriate medical care that meets the efficacy and safety needs of patients. This article reviews the clinical indications of CT and MRI in different pathologic conditions affecting the spine, including congenital, traumatic, degenerative, inflammatory, infectious and tumor disorders, as well as their main imaging features. It is intended to be a pictorial guide to clinicians involved in the diagnosis and treatment of spinal disorders.

Is the Severity of Cervical Foraminal Stenosis Related to the Severity and Sidedness of Symptoms?

(1) Background: Cervical foraminal stenosis (CFS) is a common cause of axial neck and arm pain. The aim of this study was to determine the relationship between the severity of CFS and clinical symptoms in terms of severity and sidedness. (2) Methods: We retrospectively reviewed 75 consecutive patients with degenerative CFS. We graded 900 foramina from C3–4 to T1–2 using Park’s grading system. We collected visual analogue scale (VAS) and neck disability index (NDI) values from the neck and both arms. We analyzed the relationships with CFS grades and total number. We defined four types of left/right dominance of CFS (none, left-dominant, right-dominant, and both) by comparing left and right sides using total counts and maximal grade of CFS, respectively. We compared arm pain sidedness (no arm pain, left-only, right only, and bilateral) among different left and right CFS dominance types. (3) Results: Mean neck and left and right arm VAS scores were 4.4 ± 2.5, 4.9 ± 1.6, and 4.6 ± 2.0, respectively. The mean total NDI was 16.0 ± 8.0. The CFS grade at C3–4 and total count were correlated with neck VAS. Arm VAS was also correlated with CFS grade and total counts. Total NDI score was not correlated with radiological parameters. The presence and sidedness of arm pain were significantly different between left and right CFS dominance groups divided by total count of grade 2 and 3 CFS. (4) Conclusions: The CFS grade and total count were correlated with neck and arm VAS. Arm pain occurred more frequently on the side with more grade 2 and 3 CFS.

Spinal nerve signal intensity on Dixon T2-weighted water-only sequence: an important outcome predictor after lumbar transforaminal epidural injection

OBJECTIVES

To evaluate the role of Dixon T2-weighted water-fat separation technique in predicting the outcome of lumbar transforaminal epidural injections (TFESIs).

METHODS

Patients who underwent TFESI of a single spinal nerve within 3 months after magnetic resonance imaging (MRI) exam between August 2018 and April 2020 were identified. The patients were classified into positive or negative outcome groups based on the response to the TFESI procedure. Two musculoskeletal radiologists measured the signal intensity of the injected side spinal nerves, contralateral side spinal nerves, and subcutaneous fat on axial Dixon T2-weighted water-only images, and the diameter of spinal nerve on axial Dixon T2-weighted in-phase images of the pre-procedural MRI. The measured values of the injected side spinal nerves were compared between the two groups and with the contralateral side spinal nerve.

RESULTS

A total of 94 patients were included, 76 in the positive outcome group and 18 in the negative outcome group. The mean signal intensity and the nerve-to-fat signal ratio of the injected side spinal nerve were significantly higher in the positive outcome group than in the negative outcome group (793.78 vs. 679.19, p = 0.016; 4.21 vs. 3.28, p = 0.003). In the positive outcome group, the diameter of the spinal nerve was significantly higher on the injected side than on the contralateral side (6.91 mm vs. 6.37 mm, p = 0.016).

CONCLUSIONS

The mean signal intensity and the nerve-to-fat signal ratio of the spinal nerve on axial Dixon T2-weighted water-only images can help predict patient response to the TFESI.

KEY POINTS

• Applying the Dixon technique to lumbar spine MRI can help predict patient response to the TFESI procedure. • An increased nerve-to-fat signal ratio and mean spinal nerve signal intensity on axial Dixon T2-weighted water-only images predicted favorable TFESI outcomes.