Abstract
Background
Magnetic resonance myelography (MRM) with three-dimensional (3D) T2-weighted (T2W) turbo spin echo (TSE) sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) may be a guide to the etiology of low back pain.
Purpose
To research the efficiency of a 3D T2W TSE SPACE MRM sequence for visualization of anatomic details of spinal nerve root at the spinal canal and lateral recess levels in the patients with low back pain.
Material and Methods
Lumbar spinal MRM 3D T2W TSE SPACE was performed in a total of 70 patients (median age 46 years). Patients were imaged while lying in a supine position with straightened legs. According to the degree of facet arthropathy findings, patients were divided into four separate subgroups in our retrospective cross-sectional study. Spinal nerve root angle was measured within the spinal canal and at lateral recess level, and facet joint angle and lumbar lordosis measurements were measured by two radiologists, independently.
Results
Lumbar level was strongly negatively correlated with facet joint angle (r = −0.95) as well as nerve root angle within the spinal canal (NRASC) (r = –0.857) and at the lateral recess level (NRALR) (r = −0.947). Intracanal decline of the spinal root angle caused by spinal stenosis findings was also observed (P < 0.05). For the measurements of NRASC and NRALR, inter-observer correlation was 0.85 and 0.82 for the spinal canal and at lateral recess level, respectively.
Conclusion
3D T2W SPACE in NRASC and NRALR provided high resolution images for evaluation. Therefore, this method may be a qualitative guide for the clinician and the surgeon in terms of root anatomy before any intervention.
Introduction
Low back pain negatively affects patients’ quality of life, particularly in patients aged < 45 years (1,2). Diagnosing the cause of low back pain by using the correct diagnostic method is crucial for adequate and effective treatment (1,2). Lumbar spinal stenosis is a common cause of lower back pain, having a huge share in its etiology (1,2). Lumbar spinal stenosis was described first as a separate syndrome in 1954 by Verbiest. Detailed imaging of nerve root compression caused by stenosis or disc degeneration is crucial for treatment planning (1,2). Root compression can still occur in the absence of clinical symptoms (1,2). Thus, imaging is highly valuable to describe the root compression for preoperative evaluation (1,2). Compressed roots may be treated with surgical intervention that aims to release the affected compressed roots causing the clinical symptoms (1,2). Recently, interventional injection techniques aimed at the patient’s pain (nerve block, facet block, epidural steroid injection) have been more frequently employed (1,2).
Choosing the best imaging modality to define lumbar spinal root anatomy and pathologies as well as to identify the correct clinical indication before treatment is crucial (2). Lumbar spine nerve roots have a near-vertical oblique anatomy and progress from the conus to branch out of the vertebral column (2,3). In our study, we investigated a three-dimensional (3D) T2-weighted (T2W) turbo spin echo (TSE) sampling perfection with application optimized contrasts using different flip angle evolution (SPACE) magnetic resonance myelography (MRM) method which was set up in the coronal plane to observe the lumbar spinal nerve roots through their entire progression at high resolution.
We evaluated the spinal nerve roots within the spinal canal and at the lateral recess level with high-resolution images without any invasive application or contrast agent usage. We aimed to determine the effect of facet arthropathy and facet tropism on spinal nerve root angle. Meanwhile, as for the secondary target, we aimed to determine the effects of the pathologies of adjacent bone structure and intervertebral disc on spinal nerve root angles.
Material and Methods
Patient group
A total of 70 patients (47 women, 23 men; age range = 18–86 years; median age = 46 years) who had undergone lumbar spinal MRM in our radiology department due to low back pain between July 2016 and February 2017 were included in our retrospectively planned study. Patients who had previous lumbar spinal surgery for any reason were excluded from the study (Table 1). Patients who had any malignancy history or spinal vertebral fracture were excluded from the study. Patients had all been previously verbally informed about and consented to MRM examination. Patients contraindicated for MR examination (claustrophobia, patients with pacemakers, etc.) and pediatric patients were excluded from this study. Ethical board approval was obtained for this study.
Demographic and radiological data of the 70 patients.
VAS, visual analogue scale.
Patients who were included in the study were divided into four subgroups based on facet joint arthropathy. These groups were as follows: Group 1 had normal facet joints; Group 2 had mild facet arthropathy; Group 3 had moderate facet arthropathy; and Group 4 had severe facet arthropathy.
MR technique
Lumbar spinal MR examination was performed on a 1.5-T MR device (Magnetom Avanto; Siemens Healthcare, Erlangen, Germany). Magnetic resonance imaging (MRI) was performed in patients lying in the supine position with straightened legs. In the myelography examination performed to image L1–S1 vertebral levels, a T2W SPACE sequence was used. Imaging was performed at a suitable angle for lumbar lordosis in the coronal plane and parameters were as follows: TR = 1500; TE = 136; field of view (FOV) = 30 × 30 cm; slice thickness = 0.8 mm; matrix = 320 × 310; number of excitations (NEX) = 2; and EC 1 = 172.5 kHz. Imaging duration varied by patient, 7–8 min on average.
No IV medication was injected.
All image datasets were transferred to a Picture Archiving and Communication System (PACS) workstation for image analysis (Centricity® PACS; GE Healthcare, Milwaukee, WI, USA).
Image analysis
Multiplanar reconstruction (MPR) images were obtained in two more planes (axial, sagittal) in addition to the coronal plane myelography images obtained initially (Fig. 1a).
(a) Coronal plane 3D T2W TSE SPACE MRM image obtained from a 35-year-old male patient. Progression of spinal nerve roots within the spinal canal (straight blue arrows) and at the lateral recess level (curved blue arrows) is observed. Left L5 nerve ganglion (thin long arrow) and L1 vertebra pedicles (small blue stars) are also noted. (b) A 56-year-old female patient. Coronal plane 3D T2W TSE SPACE MRM imaging shows the progress of cauda equine nerve fibers within the spinal canal through their entire path. The measurement of the L5 nerve root angle was obtained before entry to the neural foramen at the L5–S1 level. The angle, formed at the point where the imaginary line from the middle of spinal canal along craniocaudal direction and the other imaginary line consistent with the spinal nerve within the spinal column cross paths, provides the spinal root angle within the spinal canal. The root angle for the right side is 16.1° as measured on this image. (c) Coronal plane myelography images (3D T2W TSE SPACE) of a 50-year-old female patient: measurement of bilateral L4 nerve roots was obtained at the lateral recess at L4–L5. Ganglions at the neural foraminal level are also observed (blue arrows). Intervertebral discs at the L4–L5 and L5–S1 levels are observed (notched arrows). Degeneration findings such as T2 signal loss and height loss are noted in intervertebral discs.
Spinal nerve root angle measurements were obtained within the spinal canal (NRASC) and at the lateral recess level (NRALR) in coronal plane images. Within the spinal canal, spinal nerve root angle measurements were obtained for all lumbar levels (from L1 to L5) and separately for the right and left sides.
An imaginary line extending along the craniocaudal direction and dividing the spinal canal equally as right and left was pictured during nerve root measurements. The angles between the imaginary line dividing the canal in half and the secondary imaginary lines tracing the spinal nerves within the canal were measured (Fig. 1b).
At the lateral recess level, nerve root angle measurement was performed as follows: the angle between the imaginary line tracing the spinal nerve consistent with the nerve fiber extending at the lateral recess level before reaching the ganglion level, and the imaginary line extending along the caudal direction from the right lateral border to the left lateral border of the thecal sac were measured (Fig. 1c).
Right and left side facet angle measurements were obtained for all lumbar levels (from L1 to L5) in MPR axial plane images. The Grobler technique was utilized, meaning that the right and left facet angles were measured in the axial slice at the level through which the facet joint’s superior articular process of the lower level vertebrae passes (4). These measurements were as follows: the angles at which the imaginary oblique lines passing through the facet joint anteromedial and posterolateral points cross paths with the imaginary transverse line passing through the vertebra corpus posterior cortex were measured (Fig. 2a and b). A total of 700 facet joint angles were obtained.
(a) Facet angle measurement technique (Grobler method): measurement was obtained at the axial plane where the lower lumbar vertebra facet joint’s superior process passes at the lumber level. Vertebra corpus (B) was drawn with an imaginary transverse line passing through its posterior cortex tangentially. (A) Imaginary oblique lines passing through the anteromedial (C) and posterolateral (D) points of right or left side facet joints were drawn at this level. Angle of the points, where these lines cross paths (curved arrows), was evaluated as the facet angle. (b) A 40-year-old female patient. Facet angle measurement is seen in the axial plane MPR image obtained with the MRM passing through L3–L4 level (coronal plane 3D T2W TSE SPACE). Right side facet angle is 59° and left side facet angle is 58°. Facet tropism is not present according to these values. Facet joints can be considered as symmetrical. This measurement was obtained separately for all lumbar levels.
Facet joints were graded in terms of facet joint arthropathy as follows: Grade 1 = normal (normal joint spacing); Grade 2 = mild (joint spacing that has thinned by 1–2 mm, millimetric osteophytes may be present, subchondral millimetric cysts, no air in joint spacing); Grade 3 = moderate (joint spacing is < 1 mm, moderate osteophytes are present, subchondral millimetric cysts, air is present in joint spacing); and Grade 4 = severe (joint spacing cannot be visualized, marked osteophytes with severe subchondral cystic changes). The relationship between facet arthropathy and NRASC, NRALR was evaluated.
Facet angle tropism was determined using the facet angle measurements of all lumbar levels. Tropism was deemed present if the angle difference between right and left facet joints was ≥7 at the same level (4).
Facet tropism was graded as mild, moderate, or severe. Tropism was graded as mild if the angle difference between right and left side facets was 7–10°, moderate if this value was 10–15°, and severe if it was >15° (4). Patients were determined to be either with tropism or without facet tropism (4). The presence of facet tropism was considered an asymmetrical facet angle and its absence was considered a symmetrical facet angle (4). The relationship between facet tropism and spinal nerve root angle was evaluated (4).
The angle of lumbar lordosis was measured in MPR sagittal plane images (5). The lordosis angle was obtained by measuring the angle of the point at which an imaginary line drawn as parallel to sacral 1 vertebra corpus upper end plateau crosses paths with another imaginary line drawn as parallel to L1 vertebra corpus upper end plateau (Fig. 3). The relationship between the angles of lumbar lordosis and the spinal nerve root was also evaluated.
A 35-year-old female patient’s lumbar lordosis angle measurement: the lordosis measurement was obtained in the MRM sagittal plane MPR image. The angle between the imaginary line passing through L1 vertebra corpus upper end plateau and another imaginary line passing through the sacral 1 vertebra upper end plateau was measured.
All measurements were made by two radiology specialists (with 8 and 10 years of experience, respectively) independently.
Statistical analysis
The distribution of variables was checked with the Kolmogorov–Smirnov test. Averages for nerve root, facet, and lordosis angles were obtained and correlations between variables were evaluated with Pearson correlation test.
Inter-observer agreement was evaluated with Gwet’s AC test. Interclass correlation coefficient (ICC) values in the range of 0.4–0.6, 0.6–0.8, or ≥0.8 indicated moderate, good, and very good agreement, respectively.
All statistical assessments were performed using Statistical Package for the Social Sciences (SPSS) software (v.22.0; SPSS Inc., Chicago, IL, USA).
Results
Group 1 had 25 patients (median age = 43.3 years). Group 2 had 29 patients (median age = 40.4 years). Group 3 had 10 patients (median age = 60 years). Group 4 had six patients (median age = 54.33 years).
The average lumbar lordosis angles were 43.30°, 46.6°, 39°, and 40° for Groups 1, 2, 3, and 4, respectively.
Relationship of lumbar level with nerve root angle and facet angle
Average spinal nerve root angle measurements for lumbar levels and average facet angle measurements for the right and left sides for all lumbar levels are shown in Table 2.
Total study population (n = 70) averages for facet angle and spinal nerve root angle.
Lumbar level was negatively correlated with nerve root angle (r = −0.857 and −0.947 within the spinal canal and at the lateral recess level, respectively). This negative correlation was particularly prominent in Groups 2 and 3. A moderate degree of correlation was present in other groups (−0.60 when r = −0.557, respectively).
Lumbar level was strongly negatively correlated with facet angle (r = −0.95).
Relationship of facet arthropathy and lordosis angle
No significant relationship was present between the degree of facet arthropathy and lumbar lordosis angle (P > 0.05).
Relationship of lordosis angle and nerve root angle
The lordosis angle was measured as 43.4° on average in our study population and was in the range of 31–63° (SD 7.65). A decline was noted in the angle for patients in Group 4, which was 40° on average. There was no statistically significant correlation detected between the lordosis angle and the canal and lateral recess level spinal nerve root angles. This was valid for all groups (P > 0.05).
Relationship of facet angle and nerve root angle
There was no statistically significant difference detected between facet angle measurements and nerve root angle measurements for all groups (P > 0.05).
Relationship of facet arthropathy and nerve root angle
No statistically significant difference was noted when the variables obtained from each group were compared with the total patient population of n = 70 (P > 0.05).
The averages for nerve root angle at the lateral recess level at L4–L5 and within the spinal canal at L5–S1 in the total patient population were significantly higher than the averages in Groups 4 and 3 (P < 0.05).
In Group 4, the average nerve root angle was negatively correlated with lumbar level at the lateral recess (r = –0.67) but there was no significant correlation with lumbar level within the spinal canal (r = 0.23).
Five patients in our population had scoliosis. Of these, one was aged 71 years and had severe scoliosis and grade 4 facet arthropathy. Two patients had no facet arthropathy and another two patients had grade 2 facet arthropathy. In the evaluation performed, the nerve root angle at the side of scoliosis was lower than the opposite side, both within the spinal canal and at the lateral recess level (Fig. 4a and b).
(a) A 27-year-old female patient. Mild scoliosis facing right is present at the L3–L4 level. It is observed that the spinal nerve root angle of the right side is lower than that of the left side at the lateral recess level (right 15.5°, left 20.7°). This patient had no facet joint arthropathy findings. (b) Spinal intracanal nerve root measurement of the same case with scoliosis. Again, the angle is lower on the scoliosis side compared with the opposite side (right side 6.9°, left side 8.4°). The difference between root angles was low in this case of mild scoliosis but an increase in difference was noted with the increase of the degree of scoliosis.
Severe stenosis findings were present in three of six patients in Group 4. Two patients had findings at the L5–S1 level and one had findings at the L4–L5 level. Spinal root angle values in Group 4 are higher, particularly at the L4–L5 level compared with other groups.
Relationship of facet tropism and nerve root angle
For each lumbar level, there was no significant relationship between facet tropism and spinal root angle relationship in both for the canal and lateral recess levels (r < 0.25 for all levels).
When we looked at rates of facet tropism, tropism was most frequently observed at the L5–S1 level (Fig. 5). We observed that a moderate and severe degree of tropisms were more frequent for the L5–S1 level and all lumbar levels (Fig. 5).
Distribution of facet joint angle tropism according to lumbar levels and grading of facet tropism (n = 70). It is observed that the incidence and the degree of tropism increase with increasing lumbar level.
Adequacy of 3D T2W TSE SPACE MRM to visualize spinal nerve roots
It was also noted that the spinal nerve roots were easily traced within the spinal canal in cases of lumbar stenosis and deformation of the roots; if compression was present, the point of compression was exhibited with the 3D T2W TSE SPACE MRM method (Fig. 6a).
(a) A 55-year-old female patient. In the axial plane images obtained with MR myelography (3D T2W TSE SPACE) and MPR, ligamentum flavum thickening at the L3–L4 level (thick blue arrow) and gathering of spinal roots caused by the stenosis which was in turn caused by grade 3 facet arthropathy (thin blue arrow) are observed. In the axial plane MPR image, it is noted that the thecal sac is compressed prominently from the posterior left side. Prominent stenosis of root angles within spinal canal is noted (blue arrow). (b) A 47-year-old male patient with left leg pain. In MPR sagittal plane and coronal MRM (3D T2W TSE SPACE) images, extruded hernia partially migrated to the superior is observed at the L5–S1 level (notched right arrow). It is also noted that the left L5 nerve is compressed at lateral recess level due to hernia (thin long arrow) (the pedicles are marked with a star and the ganglion is marked with a blue arrowhead). (c) A 36-year-old female patient. Perineural cyst localized on the left side at the L2–L3 level (curved left arrow) and spinal nerve roots within (thin long arrow) are observed. Shape change in ganglion, caused by perineural cyst compression (small thick blue arrow), is noted. Pedicles in the upper and lower levels are marked with small blue stars.
Intervertebral disc pathologies (bulging, protrusion or extruded hernia, sequestration) and compression findings and levels caused by them were easily evaluated (Fig. 6b).
Spinal nerve roots were easily traced within the spinal canal at the lateral recess and foraminal levels. Evaluation of the intervertebral disc, pedicle, and ganglion was also performed at these levels. Diagnosis of pre-ganglion expansion of nerve root surroundings or perineural cysts was also made with the myelography method (Fig. 6c).
Inter-observer agreement
Moreover, there was high correlation present in the facet angle and lumbar lordosis angle measurements (Gwet’s AC2 = 0.95 and 0.97, respectively).
For the spinal nerve root measurements, inter-observer correlation was 0.85 and 0.82 for the spinal canal and lateral recesses, respectively.
Discussion
The purpose of lumbar spinal examinations performed due to low back pain is to show nerve root compression causing radiculopathy (1,2). This bears great significance for patient comfort and morbidity, and allows the clinician to proceed with the correct treatment method (1,2).
It is evident from many previous studies from the literature that all nerve tissue and herniated disc pathologies, including lumbosacral nerve dorsal ganglions as well as stenosis, can be visualized with MRM (3,6,7). MRM was performed via different techniques in these studies (8–11).
We aimed to image the lumbar region spinal nerve roots within the spinal canal and at the lateral recess level in patients with low back pain complaints in high resolution, by using 3D T2W TSE SPACE MRM examination in our study. By doing so, we aimed to determine the effects of the pathologies of adjacent bone structure and intervertebral disc on spinal nerve root angles.
We also assessed the relationship between the measurement of lumbar lordosis angle with facet arthropathy and spinal root angle. We did not detect any statistically significant relationship. In the evaluation we conducted, by referring to a study in which the measurements of lumbar lordosis via lumbar MRI were compared to the measurements taken via upright lumbar X-ray, the examinations were performed while patients were lying in the supine position with straightened legs (5) .
There are numerous studies in the literature comparing imaging techniques for identifying the etiology of low back pain (6–12).
Although MRI is a gold standard imaging technique for degenerative disc disease research, it can be inadequate, particularly for evaluating lateral recess pathologies (2,6). In one study, MRI significantly underestimated root compression caused by degenerative changes in the lateral recess. According to this study, conventional myelography is a more effective method for evaluating the causes of radiculopathy localized in the lateral recess (12).
In another study performed in cases of lateral recess stenosis, MR findings were compared with electromyography findings; results showed that clinical and imaging findings were frequently inconsistent (13). Lumbar myelography has long been considered the gold standard for detecting radicular compression syndromes (13); however, it is invasive in nature (13). The invasive imaging methods of conventional myelography and post-myelography CT can cause many side effects, particularly headache and cerebrospinal fluid leak, but also contrast agent allergy, infection, spinal hematoma, and cerebellar tonsillar herniation (13).
A study conducted by Eberhardt et al. compared post-myelography CT and MRM in patients with lumbar spinal stenosis (9). MRM involved a 3D heavily T2W half-Fourier acquisition single-shot turbo spin echo (HASTE) sequence (9). In this study, in which dural area and volume were measured, MRM measurements were larger in the cases with severe stenosis (9). The authors considered this to be caused by the accumulation of intradural contrast agent accumulation in the case of severe stenosis (9).
In another study, conventional myelography was compared with MRM performed with 3D fast imaging with steady precision (FISP) sequence (10). In this method using a single gradient sequence, intrathecal formation and pathologies were not clearly evaluated due to high T2 contrast (10).
In their study, Aota et al. compared the conventional MRI and MRM examinations in the patients with foraminal stenosis (6). In this study, MRM images were obtained in coronal plane and with a T2* technique (6). This study concluded that MRM provides more specific information in the preoperative stage (6). The fat-saturated (FAT-SAT) technique was utilized in this study and MRM images were acquired in a slice thickness of 5 mm (6). However, in our study, we managed to downsize the slice thickness to 0.8 mm; this allowed us to evaluate nerve roots seamlessly, starting from the interior spinal canal until the neural foraminal level. The benefit of not using the FAT-SAT technique also led to increased image quality, due to the contrast difference caused by fat.
MRM was conducted with diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) mapping techniques in one of the two studies conducted by Eguchi et al. in patients with foraminal entrapment (8). It was also mentioned that nerve root has a more transverse course at the foraminal level in patients with foraminal stenosis in this study (8). According to this study, MR neurography using DWI can clearly show lumbar nerve roots, and the mean ADC in nerve root entrapment with foraminal stenosis is higher than in intact nerve roots in a scan time of approximately 10 min by using MRI at 1.5 T (8). The ADC map is limited because the tissue contrast between nerves and surrounding tissues is poor (8). We managed to acquire higher-resolution images in a shorter period of time. Moreover, it was mentioned in this study that the ADC values of compressed roots are higher (8). However, in our study, we could visualize the nerve root in such a manner to directly point out the compressed level directly in all three planes, without any need of measurement.
In a study conducted by Kim et al., it was stated that the two most significant findings of root compression at foraminal level are the visualization of the swelling of dorsal root ganglion and running course abnormality of L5 exiting root at foramen or extraforamen (7). We have also observed in our study that in comparison with the other group, nerve root angle at the lateral recess level is higher in our patient group with a high angle of facet arthropathy. In addition, we comfortably observed the changes caused by compression in the dorsal root ganglion, but we did not assess them in this study. This may be the subject of another study.
In the MRM study conducted by Eguchi et al. (11) on diffusion tensor imaging, it was observed that tracts that might be apparently missing in tractograms of patients with foraminal stenosis does not necessarily indicate loss of nerve fibers or paralysis, but there is some isotropic change and fractional anisotropy (FA) reduction (11). We, on the other hand, as mentioned before, were able to track the nerve root alongside its entire course seamlessly. Moreover, we could easily observe its relations with surrounding tissues via the MPR images we acquired.
In the study conducted by Kojima et al. (10) on patients with L5 radiculopathy, morphology of dorsal root ganglions was assessed (10). A 3D balance T1 gradient sequence was utilized in this study and it is affected by TR durations and B0 homogeneity (10). On the other hand, the T2W TSE SPACE sequence we utilized does not suffer from such sensitivity.
However, we were able to detail intradural structures in our study, due to the high spatial resolution. Since there is no gradient echo technique in the SPACE sequence, the utilization of the spin echo technique and the radiofrequency (RF) pulse in various angles allowed us to obtain high contrast images.
SPACE uses non-selective, short refocusing pulse trains consisting of RF pulses with variable flip angles. This allows for very high turbo factors (>100) and high sampling efficiency. The SPACE sequence produces high-resolution isotropic images that can be reconstructed in multiple planes. SPACE sequences are less sensitive to susceptibility, flow, and chemical shift artefacts, which makes it superior over conventional TSE (3).
Another aspect of our study which differs from the other studies is the absence of any fat-suppression technique (9). Thus, the contrast caused specifically by epidural fat or perineural fat within the spinal canal helped the imaging contrast. This was also a contributing finding in the evaluation of stenosis.
As no fat-suppression technique was utilized, lateral recess stenosis or ligamentum flavum thickening were evaluated more precisely owing to the contrast caused by the present fat.
For this study, along with the isotropic images with a slice thickness of 0.8 mm obtained with the 3D T2W SPACE technique, we also obtained high-resolution MPR axial and sagittal plane images. In particular, the radix and ganglion levels, lateral recess levels, which were not clearly visualized in previous examinations, were evaluated in high resolution in our study (12). The high resolution allowed the evaluation of morphological changes or nerve root angle caused by disc pathologies in nerve roots. Even the millimetric intracanal sequestrum disc pathologies were easily identified due to high spatial resolution.
Lumbar spinal root angle values gradually decreased towards the caudal but, interestingly, the root angle measurement at the lateral recess level was higher in patients with severe facet arthropathy in Group 4 when compared with other groups. An increase in the root angle at the lateral recess level was noticeable in patients with paracentral or central disc pathologies, in contrast to patients with stenosis. The reason for this is that disc pathology or facet arthropathy causing spinal nerve compression can cause an expansion in the root angle.
In the future, the 3D T2W TSE SPACE sequence obtained in the coronal plane for approximately 7–8 min as used in our study may replace the three-plane T2W sequences obtained in lumbar MRI. A new lumbar spinal MR protocol will require a shorter amount of imaging time. Greater image quality may be created with additional T1-weighted sequences. Images comparable to lumbar CT in terms of high resolution may be obtained.
As for the disadvantages of our study, our patient population lacked diversity. Our patient group mainly comprised patients with chronic low back pain with spinal degeneration. For example, there were no patients with acute low back pain or patients who had undergone surgery and yet still had persistent low back pain. This may be a subject of a future study. In addition, the fact that we did not correlate our radiological findings with a clinical test (such as electromyography) or a surgical intervention is another disadvantage.
In conclusion, the visualization and clarification of spinal root anatomy and compression to determine low back pain etiology could serve as a “guidebook” for treatment-oriented intervention or surgery. Images obtained with 3D T2W SPACE allowed the high-resolution evaluation of spinal nerve roots within the spinal canal and at the lateral recess level. Accompanying stenosis or degenerative disc pathologies and their effects on nerve roots were easily visualized with great image quality and reliability. This method can deliver adequate quality for guiding the clinician and surgeon in the preoperative stage in terms of root anatomy.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.