Abstract
Objectives:
To compare the grading of lumbar degenerative disc disease (DDD), Modic end-plate changes (MEPC) and identification of high intensity zones (HIZ) on a combination of sagittal T1weighted turbo spin echo (T1W TSE), T2weighted fast spin echo (T2W FSE) and short tau inversion recovery (STIR) sequences (routine protocol) with a single sagittal T2W FSE Dixon MRI sequence which provides in-phase, opposed-phase, water only and fat only images in a single acquisition (Dixon protocol).
Methods:
50 patients underwent lumbar spine MRI using the routine protocol with the addition of a T2W FSE Dixon sequence. DDD grade, MEPC and HIZ for each disc level were assessed on the routine and Dixon protocols. Each protocol was reviewed independently by three readers (consultant musculoskeletal radiologists with 26-, 8- and 4 years’ experience), allowing assessment of inter-reader agreement and inter protocol agreement for each assessed variable.
Results:
The study included 17 males and 33 females (mean age 51 years; range 8–82 years). Inter-reader agreement for DDD grade on the routine protocol was 0.57 and for the Dixon protocol was 0.63 (p = 0.08). Inter-reader agreement for MEPC on the routine protocol was 0.45 and for the Dixon protocol was 0.53 (p = 0.02), and inter-reader agreement for identification of the HIZ on the routine protocol was 0.52 and for the Dixon protocol was 0.46 (p = 0.27). Intersequence agreement for DDD grade ranged from 0.61 to 0.97, for MEPC 0.46–0.62 and for HIZ 0.39–0.5.
Conclusion:
A single sagittal T2W FSE Dixon MRI sequence could potentially replace the routine three sagittal sequence protocol for assessment of lumbar DDD, MEPC and HIZ resulting in ~60% time saving.
Advances in knowledge:
Grading of lumbar DDD, presence of Modic changes and high intensity zones were compared on sagittal T1W TSE, T2W FSE and STIR sequences with a T2W FSE Dixon sequence, with fair-to-good correlation suggesting that three conventional sequences could be replaced by a single Dixon sequence.
Introduction
Low back pain (LBP)1,2 and sciatica3,4 are common clinical problems, which if persisting after adequate conservative measures may require investigation with lumbar spine MRI.5 Lumbar spine MRI studies typically comprise a combination of sagittal T1 weighted turbo spin echo (T1W TSE), sagittal T2 weighted fast spin echo (T2 W FSE) and axial T2 W FSE sequences,6,7 with the addition of axial T2W TSE and sagittal or coronal short tau inversion recovery (STIR) sequences also commonly recommended,8,9 resulting in a typical imaging time of 20–25 min.
The Dixon sequence is a well-established technique with a variety of musculoskeletal applications, providing fat only (FO), water only (WO), in-phase (IP) and opposed-phase (OP) images in a single sequence.10 In the spine, gradient echo chemical shift imaging (CSI) has been extensively used to characterise indeterminate marrow lesions and differentiate benign from pathological vertebral collapse.11 The T2W FSE Dixon sequence has been advocated for the assessment of malignant marrow disease as an alternative to the T1W TSE sequence allowing a reduction in scan times,12–14 and also as an alternative technique for fat suppression.15,16 Most recently, Zanchi et al demonstrated that by using the T2W FSE Dixon sequence in patients with non-specific LBP, the sagittal T1W TSE sequence was not required for the assessment of focal marrow lesions, facet arthropathy, spondylolysis, vertebral fractures and foraminal stenosis.17 In addition to these features, lumbar spine MRI in the setting of degenerative disc disease (DDD) requires assessment of the degree of DDD, the presence of disc bulges and prolapses, the identification of annular tears manifest by the high intensity zone (HIZ), and the assessment of Modic end-plate changes (MEPC).18–20
Following introduction of the sagittal T2W FSE Dixon sequence into our MRI spine protocol for the assessment of vertebral marrow, it was noted that the IP sequence had similar imaging characteristics to the conventional sagittal T2W FSE sequence. The aim of the current study was to investigate if the sagittal T2W FSE Dixon sequence was equivalent to a combination of sagittal T1W TSE, T2W TSE and STIR sequences from a routine lumbar spine protocol for the assessment of lumbar DDD, the classification of MEPC and the identification of lumbar HIZ, thus allowing a potential significant reduction in scan times.
Methods and materials
The study was approved by the local Research and Innovation Centre of The Institute of Orthopaedics under the Integrated Research Application System number 262826, with no requirement for informed patient consent.
Between 5 January 2020 and 2 June 2020, 50 patients underwent lumbar spine MRI studies for various combinations of LBP and/or sciatica, all imaged with a routine lumbar spine protocol and the addition of a sagittal T2W FSE Dixon sequence. All studies were performed on a 1.5T MRI Unit (Magnetom Sola, Siemens, Germany). The imaging protocol is presented in Table 1. Patients were not included in the study if there was either instrumented or non-instrumented spinal fusion, or in the presence of a lumbar degenerative scoliosis since the Modified Pfirrmann Grading System described by Griffiths et al21 for scoring lumbar DDD did not allow for the asymmetrical disc collapse seen in this condition. Age and gender of the patients was noted. For each case, the following MRI data were collected:
Table 1.
Basic MRI parameters for routine lumbar spine MRI study and T2W FSE Dixon sequence (excluding the axial T2W FSE sequence which would be used for both protocols)
| Sequence | TR (ms) | TE (ms) | TI (ms) | Slice thickness (mm) | FOV (mm) | Matrix | Scan time (min:s) |
|---|---|---|---|---|---|---|---|
| Sagittal T1W TSE | 450–699 | 10–20 | N/A | 4 × 0.4 | 350 × 100 | 464 × 80 | 02:17 |
| Sagittal T2W FSE | TR 3000 (minimum) | 70 or higher | N/A | 4 × 0.4 | 350 × 100 | 512 × 80 | 03:35 |
| Sagittal STIR | 3500 minimum) | 70 or higher | 180–220 | 4 × 0.4 | 350 × 100 | 384 × 95 | 04:38 |
| Total | 14:25 | ||||||
| Sagittal T2W FSE Dixon | TR 3000 (minimum) | 70 or higher | N/A | 4 × 0.4 | 380 × 50 | 416 × 100 | 01:59 |
FOV, field of view; TE, echo time; TI, inversion time; TR, repetition time; T2W FSE, T2 weighted fast spin echo; T1W TSE, T1 weighted turbo spin echo.
Lumbar DDD grade according to the Modified Pfirrmann grading system21 at each disc level from L1-L2 to L5-S1 (total 250 discs) on the sagittal conventional T2W FSE and IP T2W FSE Dixon sequences.
-
The presence and type of MEPC at each disc level from L1-L2 to L5-S1 (total 250 discs)18:
Type 1 (inflammatory); low signal intensity (SI) on T1W TSE or FO T2W FSE Dixon sequences and high SI on T2W FSE and STIR sequences, or IP and WO T2W FSE Dixon sequences.
Type 2 (fatty): high SI on T1W TSE or FO T2W FSE Dixon sequences, high SI on T2W FSE or IP T2W FSE Dixon sequences, and low SI on STIR or WO T2W FSE Dixon sequences.
Type 3 (sclerotic): low SI on all sequences.
Mixed: any combination of Types 1, 2 or 3.
Presence of the HIZ at each disc level from L1-L2 to L5-S1 (total 250 discs)19: manifest by focal high SI in the posterior annulus on the sagittal conventional T2W FSE or IP T2W FSE Dixon sequences.
The conventional sagittal T2W FSE sequence was viewed independently for grading of lumbar DDD and identification of HIZs by three readers, a Consultant Musculoskeletal Radiologist with 26 years’ experience (Reader 1), a Consultant Musculoskeletal Radiologist with 4 years’ experience (Reader 2), and a Consultant Musculoskeletal Radiologists 8 years’ experience (Reader 3) respectively. These readers also used the sagittal T1W TSE and STIR sequences for identifying and classifying MEPC. Following a period of approximately 3 months, the sagittal IP T2W FSE Dixon sequence was viewed independently for grading of lumbar DDD and identification of HIZs by the same three readers, who also used the sagittal FO and WO T2W FSE Dixon sequences for identifying and classifying MEPC.
Statistical analysis
The Modified Pfirrmann grading system for lumbar DDD has eight different stages for DDD based on a combination of SI from the nucleus pulposus, distinction between the inner and outer fibres of the posterior annulus and disc height.21 For the purposes of interobserver correlation of DDD, Grades 1–3 were combined since they equate to a normal disc for patient age. Grades 4 and 5 were combined since they equate to early DDD. Grade 6 was kept separate since it equates to moderate DDD. Grades 7 and 8 were combined since they equate to advanced DDD (Table 2).
Table 2.
The grading system for degenerative disc disease (modified from21)
| Grade for study | Grade from paper | Signal from nucleus and inner fibres of anulus | Distinction between inner and outer fibres of anulus at posterior aspect of disc | Height of disc |
|---|---|---|---|---|
| 1 | 1 | Uniformly hyperintense (=CSF) | Distinct | Normal |
| 1 | 2 | Hyperintense (>presacral fat;<CSF) ± hypointense intranuclear cleft | Distinct | Normal |
| 1 | 3 | Hyperintense (<presacral fat) | Distinct | Normal |
| 2 | 4 | Mildly hyperintense (slightly >outer fibres of anulus) | Indistinct | Normal |
| 2 | 5 | Hypointense (=outer fibres of anulus) | Indistinct | Normal |
| 3 | 6 | Hypointense | Indistinct | <30% reduction disc height |
| 4 | 7 | Hypointense | Indistinct | 30–60% reduction disc height |
| 4 | 8 | Hypointense | Indistinct | >60% reduction disc height |
CSF, cerebrospinal fluid.
The first analysis examined the agreement between readers 1, 2 and 3 for the routine lumbar spine MRI sequences and the T2W FSE Dixon sequence, while the second analysis examined the agreement between the two sequences for each of the three readers. Since all outcomes were measured on a categorical basis, the agreement between readers and between sequences was assessed using the κ statistic. Additionally, the size of the inter-reader agreement was compared between the conventional and Dixon methods. The κ values and their standard errors were used to perform a z-test to examine if there were statistical differences between the two sequences.
Results
The study group included 50 patients, 17 males and 33 females with mean age of 51 years (range 8–82 years). Table 3 presents the basic data for grading of DDD, MEPC and HIZ for the three readers and the two sequences. This demonstrated the majority of discs showing either no or mild degenerative changes (Grade 1 and 2) (Figure 1), with between 11 and 26% of discs showing Grade 3 and 4 DDD (Figures 1 and 2). MEPC were seen at 11–17% of disc levels (Figures 3 and 4), while a HIZ was noted at 4–7% of disc levels (Figure 5).
Table 3.
Summary of responses for both methods for three readers
| Variable | Category | Reader 1 | Reader 2 | Reader 3 | |||
|---|---|---|---|---|---|---|---|
| T2W FSE | Dixon | T2W FSE | Dixon | T2W FSE | Dixon | ||
| Grade DDD | 1 | 112 (45%) | 114 (46%) | 80 (32%) | 80 (32%) | 111 (44%) | 111 (44%) |
| 2 | 110 (44%) | 98 (39%) | 132 (53%) | 117 (47%) | 81 (32%) | 82 (33%) | |
| 3 | 17 (7%) | 16 (6%) | 21 (8%) | 27 (11%) | 31 (12%) | 31 (12%) | |
| 4 | 11 (4%) | 22 (9%) | 17 (7%) | 26 (10%) | 27 (11%) | 26 (10%) | |
| MEPC | None | 219 (88%) | 211 (84%) | 217 (87%) | 205 (82%) | 216 (86%) | 217 (87%) |
| 1 | 16 (6%) | 8 (3%) | 23 (9%) | 13 (5%) | 3 (1%) | 7 (3%) | |
| 2 | 2 (1%) | 11 (4%) | 5 (2%) | 16 (6%) | 19 (8%) | 7 (3%) | |
| 3 | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 1 (0.4%) | 0 (0%) | |
| Mixed | 13 (5%) | 20 (8%) | 5 (2%) | 16 (6%) | 11 (4%) | 18 (7%) | |
| HIZ | No | 232 (93%) | 233 (93%) | 234 (94%) | 236 (94%) | 220 (88%) | 231 (92%) |
| Yes | 18 (7%) | 17 (7%) | 16 (6%) | 14 (6%) | 30 (12%) | 19 (8%) | |
DDD, Degenerative disc disease; HIZ, High intensity zone; MEPC, Modic endplate changes;T2W FSE, T2 weighted fast spin echo.
Figure 1.
A 70-year-old female being imaged for low back pain. (a) Sagittal T2W FSE and (b) IP T2W FSE Dixon MR images showing Grade 1 DDD at L1-L2, L3-L4, L4-L5 and L5-S1 (arrows) with Grade 3 DDD at L2-L3 (arrowhead) manifest by loss of T2W nuclear SI and slight loss of disc height. Note is made of a small intra dural lesion (black arrows) which is seen on both sequences. DDD, degenerative discdisease; IP, in-phase; SI, signal intensity; T2W FSE, T2weighted fast spin echo.
Figure 2.
A 76-year-old female being imaged for low back pain. (a) Sagittal T2W FSE and (b) IP T2W FSE Dixon MR images showing Grade 3 DDD at L3-L4 (arrows) and Grade 4 DDD at L2-L3 (arrowhead). DDD, degenerative discdisease; IP, in-phase; T2W FSE, T2 weighted fast spin echo.
Figure 3.
A 63-year-old male being imaged for low back pain. (a) Sagittal T1W TSE, (b) sagittal STIR, (c) sagittal FO T2W FSE Dixon and (d) sagittal WO T2W FSE Dixon MR images showing Grade 4 DDD at L3-L4 with associated prominent Type 1 MEPC (arrows). DDD, degenerative disc disease; MEPC, Modic end-plate changes; STIR, short tau inversion recovery; T1WTSE, T1 weighted turbo spin echo; T2W FSE, T2weighted fast spin echo; WO, water only.
Figure 4.
A 49-year-old male being imaged for low back pain. (a) Sagittal T1W TSE, (b) sagittal T2W FSE, (c) sagittal FO T2W FSE Dixon and (d) sagittal IP T2W FSE Dixon MR images showing Grade 2 DDD at L5-S1 with associated Type 2 MEPC (arrows). DDD, degenerative disc disease; FO, fat only; IP, in-phase; MEPC, Modic end-plate changes; STIR, shorttau inversion recovery; T1W TSE, T1weighted turbo spin echo; T2W FSE, T2weighted fast spin echo.
Figure 5.
A 44-year-old female being imaged for low back pain. (a) Sagittal T2W FSE and (b) IP T2W FSE Dixon MR images showing Grade 2 DDD at L5-S1 (arrows) and a posterior central HIZ (black arrow). DDD, degenerative disc disease; HIZ, high intensity zone; T2W FSE, T2weighted fast spin echo.
Table 4 presents the inter-reader agreement for the three readers for each sequence independently. For all parameters, the agreement between readers was roughly similar for the conventional T2W FSE and T2W FSE Dixon methods. The agreement between readers was significantly higher for the Dixon method for MEPC (p = 0.02), although the κ value was only 0.08 units higher for this method. There was also slight evidence that agreement between readers for grade of DDD was higher for the Dixon method, although this difference did not quite reach statistical significance (p = 0.08). There was no significant difference between methods for identification of the HIZ (p = 0.27).
Table 4.
Inter-reader agreement for the three readers
| Variable | Conventional κ (95% CI) | Dixon κ (95% CI) | Difference estimate (95% CI) | p-value |
|---|---|---|---|---|
| Grade of DDD | 0.57 (0.52, 0.62) | 0.63 (0.58, 0.68) | 0.06 (-0.01, 0.13) | 0.08 |
| MEPC | 0.45 (0.40, 0.50) | 0.53 (0.48, 0.58) | 0.08 (0.48, 0.15) | 0.02 |
| HIZ | 0.52 (0.45, 0.59) | 0.46 (0.39, 0.54) | −0.06 (-0.16, 0.04) | 0.27 |
CI, confidence interval; DDD, Degenerative disc disease; HIZ, High intensity zone; MEPC, Modic endplate changes.
Table 5 presents the intersequence agreement for each of the three readers. The results suggested good-to-very good agreement between techniques for the grade of DDD. However, agreement was only moderate for MEPC and HIZ.
Table 5.
Intersequence agreement for the three readers
| Variable | Reader 1 κ (95% CI) | Reader 2 κ (95% CI) | Reader 3 κ (95% CI) |
|---|---|---|---|
| Grade of DDD | 0.66 (0.56, 0.75) | 0.61 (0.53, 0.69) | 0.97 (0.89, 1.00) |
| MEPC | 0.62 (0.54, 0.71) | 0.46 (0.38, 0.54) | 0.47 (0.38, 0.55) |
| HIZ | 0.48 (0.35, 0.60) | 0.50 (0.38, 0.63) | 0.39 (0.27, 0.51) |
CI, confidence interval; DDD, Degenerative disc disease; HIZ, High intensity zone; MEPC, Modic endplate changes.
Discussion
The current study has investigated the potential for a single sagittal T2W FSE Dixon sequence of the lumbar spine (which provides FO, WO, IP and OP images) to replace sagittal T1W TSE, T2W FSE and STIR sequences for the assessment of lumbar DDD grade, the presence and type of MEPC and the presence of a HIZ, with a potential time saving of 8 min 31 s. The inter-reader agreement was significantly higher for assessment of MEPC using the Dixon and also higher for grade of DDD, although the latter did not quite reach statistical significance. There was no significant difference between methods for identification of the HIZ. Good-to-very good agreement between the two techniques was also identified for the grade of DDD. Therefore, these results would suggest that the single T2W FSE Dixon sequence could be used as the only sagittal sequence for lumbar spine MRI without any significant loss of diagnostic information. Using the combination of a single sagittal T2W FSE Dixon sequence and an axial T2W FSE sequence would result in a ~60% reduction in scan length (Table 1).
When suggesting the replacement of conventional imaging sequences which have been established for decades with newer sequences, it is important to consider the relevance of the variables that are being assessed in relation to symptoms and clinical decision making. A classification of lumbar intervertebral disc degeneration was initially proposed by Pfirrmann et al in 2001, the stated aim being for the comparison of data from different investigations rather than for correlation with patient symptoms and effect on treatment.22 Using a 5-point grading system, the authors demonstrated a very high level of inter- and intraobserver agreement. This system was then modified by Griffiths et al21 into an 8-point scoring system which showed interobserver agreement similar to the current study (weighted κ: 0.65–0.67). The latter classification was used in the current study, with all discs initially graded from 1 to 8, but then regraded into four grades for statistical purposes based on the fact that Grades 1–3 could be taken to represent normal discs for age, Grades 4–5 early disc degeneration manifest by variable loss of T2W nuclear SI without loss of disc height, Grade 6 moderate disc degeneration manifest by <30% disc height loss, and Grades 7–8 advanced disc degeneration based on >30% disc height loss (Table 2). Neither of the grading systems included assessment of disc bulge or prolapse, and these factors were also not considered in the current study since they are evident on the axial T2W FSE sequence which better assesses their relationship to nerve root compression and canal stenosis. Recent review articles comparing the findings on lumbar spine MRI with symptoms of LBP and sciatica have mentioned lumbar DDD but not commented on its relationship to symptoms.5,23 Therefore, the simple grading of lumbar DDD may not be of clinical relevance, as opposed to the effect of secondary changes in disc morphology which may result in lumbar nerve root compression. In the current study, MEPC were identified in 11–12% of cases on the conventional T2W FSE sequence, and 13–17% on the T2W FSE Dixon sequence. Systematic literature reviews have suggested that MEPC may be relatively specific markers of LBP but have variable sensitivity, and the way in which the identification of MEPC affects the management of lumbar degenerative disc disease is unclear.18,24,25 Similarly, systematic literature reviews on the lumbar HIZ have suggested that it may be a marker of LBP, but published studies are often limited by small sample size, heterogeneity of study populations, and lack of standardisation of HIZ phenotype.26,27 Therefore, the importance of identifying both MECP and HIZ in terms of guiding patient management remains unclear. In the current study, inter-reader agreement for MEPC was significantly better on the T2W FSE Dixon sequence and equivalent for identification of the HIZ.
The T2W FSE Dixon sequence has several other potential benefits compared to standard MRI sequences in the lumbar spine, including improved fat suppression15,16 and the assessment of vertebral metastases and myeloma.12–14 The latter studies have suggested that conventional T1W TSE MRI sequences could be replaced by a T2W FSE Dixon sequence with resultant time saving. Most recently, Zanchi et al assessed the role of T2W FSE Dixon sequence in patients with non-specific LBP and/or lumbar radiculopathy at 3T,17 similar to the current study. However, their emphasis was on the assessment of features which are traditionally assessed on a sagittal T1W TSE sequence rather than the assessment of lumbar DDD which was the focus of the current study. They assessed eight independent factors, focal bone marrow abnormalities, MEPC, degenerative changes in the vertebral corners, Schmorl’s nodes, endplate fractures, foraminal stenosis, spondylolysis and facet arthropathy, finding that a simplified protocol using only the FO, WO and IP T2W FSE Dixon sequence was equivalent to the same protocol with the addition of a T1W TSE sequence. They concluded that the T1W TSE could be eliminated for the imaging of their target population without any loss of diagnostic information. A further potential benefit of the Dixon sequence is that of quantitative CSI using the IP and OP sequences for the assessment of indeterminate vertebral marrow changes. This has typically been performed in the spine using gradient echo techniques and has been shown to be of value for the differentiation of non-neoplastic marrow lesions from neoplastic marrow replacement, and the differentiation between benign osteoporotic compression fractures and pathological vertebral compression fractures.11 Most recently, the value of gradient echo CSI for the characterisation of focal nodular marrow hyperplasia has been reported.28 However, the potential for differentiation between yellow marrow, red marrow and focal marrow lesions using T1W and T2W FSE Dixon sequences has also been reported,29 and a further study has shown that CSI using IP and OP T2W FSE Dixon sequences is comparable to the more established techniques of T1W gradient echo CSI.30
The study has several limitations. The study population of 50 patients was relatively small, but when considered as individual disc/endplate units (n = 250), it is felt that this was adequate and that increasing patient numbers would unlikely have changed the results. Levels of inter-reader agreement ranged from moderate-to-good, which were not as high as the earlier studies by Pfirrmann et al22 and Griffiths et al21 but were quite consistent if not better than those recently reported by Zanchi et al.17 There was no assessment of disc bulge, prolapse or canal stenosis, but MRI based grading systems for both canal stenosis and disc herniation utilise axial T2W FSE sequences31–33 , and therefore these aspects of lumbar DDD would not be affected by the substitution of the three routinely used sagittal sequences with the single T2W FSE Dixon sequence. There was also no assessment of foraminal compromise which is traditionally assessed on sagittal T1W TSE images 34, but this was included in the study by Zanchi et al17.
In conclusion, the current study suggests that a single sagittal T2W FSE Dixon sequence utilising the FO, IP and WO images could replace the sagittal T1W TSE, T2W FSE and STIR sequences which are commonly used in lumbar spine imaging for the assessment of lumbar DDD, MEPC and HIZ with a subsequent reduction of scan time by ~60% at 1.5T. Further studies at both 1.5T and 3T utilising MR Units from different manufacturers are recommended to substantiate these findings, which could have a very significant impact on cost implications for lumbar spine MRI.
Footnotes
Acknowledgements: The authors would like to acknowledge Mr Paul Bassett for his statistical input.
Contributor Information
Asif Saifuddin, Email: asif.saifuddin@nhs.net.
Ramanan Rajakulasingam, Email: ramanan.rajakulasingham1@nhs.net.
Rodney Santiago, Email: rodney.santiago@nhs.net.
Mateen Siddiqui, Email: mateen.siddiqui@nhs.net.
Michael Khoo, Email: michael.khoo@nhs.net.
Ian Pressney, Email: ianpressney@nhs.net.
REFERENCES
- 1.Fayaz A, Croft P, Langford RM, Donaldson LJ, Jones GT. Prevalence of chronic pain in the UK: a systematic review and meta-analysis of population studies. BMJ Open 2016; 6: e010364. doi: 10.1136/bmjopen-2015-010364 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Fatoye F, Gebrye T, Odeyemi I. Real-World incidence and prevalence of low back pain using routinely collected data. Rheumatol Int 2019; 39: 619–26. doi: 10.1007/s00296-019-04273-0 [DOI] [PubMed] [Google Scholar]
- 3.Konstantinou K, Dunn KM. Sciatica: review of epidemiological studies and prevalence estimates. Spine 2008; 33: 2464–72. [DOI] [PubMed] [Google Scholar]
- 4.Jensen RK, Kongsted A, Kjaer P, Koes B. Diagnosis and treatment of sciatica. BMJ 2019; 359: l6273. doi: 10.1136/bmj.l6273 [DOI] [PubMed] [Google Scholar]
- 5.Roudsari B, Jarvik JG. Lumbar spine MRI for low back pain: indications and yield. AJR Am J Roentgenol 2010; 195: 550–9. doi: 10.2214/AJR.10.4367 [DOI] [PubMed] [Google Scholar]
- 6.Demaerel P, Sunaert S, Wilms G. Sequences and techniques in spinal MR imaging. JBR-BTR 2003; 86: 221–2. [PubMed] [Google Scholar]
- 7.Shah LM, Hanrahan CJ. MRI of spinal bone marrow: Part I, techniques and normal age-related appearances. AJR Am J Roentgenol 2011; 197: 1298–308. doi: 10.2214/AJR.11.7005 [DOI] [PubMed] [Google Scholar]
- 8.Lakadamyali H, Tarhan NC, Ergun T, Cakır B, Agıldere AM. Stir sequence for depiction of degenerative changes in posterior stabilizing elements in patients with lower back pain. AJR Am J Roentgenol 2008; 191: 973–9. doi: 10.2214/AJR.07.2829 [DOI] [PubMed] [Google Scholar]
- 9.Gupta R, Mittal P, Mittal A, Mittal K, Gupta S, Kaur R. Additional merit of coronal stir imaging for MR imaging of lumbar spine. J Craniovertebr Junction Spine 2015; 6: 12–15. doi: 10.4103/0974-8237.151582 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.van Vucht N, Santiago R, Lottmann B, Pressney I, Harder D, Sheikh A, et al. The Dixon technique for MRI of the bone marrow. Skeletal Radiol 2019; 48: 1861–74. doi: 10.1007/s00256-019-03271-4 [DOI] [PubMed] [Google Scholar]
- 11.Suh CH, Yun SJ, Jin W, Park SY, Ryu C-W, Lee SH. Diagnostic performance of in-phase and Opposed-Phase Chemical-Shift imaging for differentiating benign and malignant vertebral marrow lesions: a meta-analysis. AJR Am J Roentgenol 2018; 211: W188–97. doi: 10.2214/AJR.17.19306 [DOI] [PubMed] [Google Scholar]
- 12.Hahn S, Lee YH, Suh J-S. Detection of vertebral metastases: a comparison between the modified Dixon turbo spin echo T 2 weighted MRI and conventional T 1 weighted MRI: a preliminary study in a tertiary centre. Br J Radiol 2018; 16: 20170782. doi: 10.1259/bjr.20170782 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Maeder Y, Dunet V, Richard R, Becce F, Omoumi P. Bone marrow metastases: T2-weighted Dixon spin-echo fat images can replace T1-weighted spin-echo images. Radiology 2018; 286: 948–59. doi: 10.1148/radiol.2017170325 [DOI] [PubMed] [Google Scholar]
- 14.Danner A, Brumpt E, Alilet M, Tio G, Omoumi P, Aubry S. Improved contrast for myeloma focal lesions with T2-weighted Dixon images compared to T1-weighted images. Diagn Interv Imaging 2019; 100: 513–9. doi: 10.1016/j.diii.2019.05.001 [DOI] [PubMed] [Google Scholar]
- 15.Pokorney AL, Chia JM, Pfeifer CM, Miller JH, Hu HH. Improved fat-suppression homogeneity with mDIXON turbo spin echo (TSE) in pediatric spine imaging at 3.0 T. Acta Radiol 2017; 58: 1386–94. doi: 10.1177/0284185117690424 [DOI] [PubMed] [Google Scholar]
- 16.Lee S, Choi DS, Shin HS, Baek HJ, Choi HC, Park SE, et al. Fse T2-weighted two-point Dixon technique for fat suppression in the lumbar spine: comparison with SPAIR technique. Diagn Interv Radiol 2018; 24: 175–80. doi: 10.5152/dir.2018.17320 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Zanchi F, Richard R, Hussami M, Monier A, Knebel J-F, Omoumi P. Mri of non-specific low back pain and/or lumbar radiculopathy: do we need T1 when using a sagittal T2-weighted Dixon sequence? Eur Radiol 2020; 30: 2583–93. doi: 10.1007/s00330-019-06626-6 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Zhang Y-H, Zhao C-Q, Jiang L-S, Chen X-D, Dai L-Y. Modic changes: a systematic review of the literature. Eur Spine J 2008; 17: 1289–99. doi: 10.1007/s00586-008-0758-y [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Khan I, Hargunani R, Saifuddin A. The lumbar high-intensity zone: 20 years on. Clin Radiol 2014; 69: 551–8. doi: 10.1016/j.crad.2013.12.012 [DOI] [PubMed] [Google Scholar]
- 20.Clarençon F, Law-Ye B, Bienvenot P, Cormier Évelyne, Chiras J. The degenerative spine. Magn Reson Imaging Clin N Am 2016; 24: 495–513. doi: 10.1016/j.mric.2016.04.008 [DOI] [PubMed] [Google Scholar]
- 21.Griffith JF, Wang Y-XJ, Antonio GE, Choi KC, Yu A, Ahuja AT, et al. Modified Pfirrmann grading system for lumbar intervertebral disc degeneration. Spine 2007; 32: E708–12. doi: 10.1097/BRS.0b013e31815a59a0 [DOI] [PubMed] [Google Scholar]
- 22.Pfirrmann CWA, Metzdorf A, Zanetti M, Hodler J, Boos N. Magnetic resonance classification of lumbar intervertebral disc degeneration. Spine 2001; 26: 1873–8. doi: 10.1097/00007632-200109010-00011 [DOI] [PubMed] [Google Scholar]
- 23.Ract I, Meadeb J-M, Mercy G, Cueff F, Husson J-L, Guillin R. A review of the value of MRI signs in low back pain. Diagn Interv Imaging 2015; 96: 239–49. doi: 10.1016/j.diii.2014.02.019 [DOI] [PubMed] [Google Scholar]
- 24.Jensen TS, Karppinen J, Sorensen JS, Niinimäki J, Leboeuf-Yde C. Vertebral endplate signal changes (Modic change): a systematic literature review of prevalence and association with non-specific low back pain. Eur Spine J 2008; 17: 1407–22. doi: 10.1007/s00586-008-0770-2 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Fields AJ, Battié MC, Herzog RJ, Jarvik JG, Krug R, Link TM, et al. Measuring and reporting of vertebral endplate bone marrow lesions as seen on MRI (Modic changes): recommendations from the ISSLS degenerative spinal phenotypes group. Eur Spine J 2019; 28: 2266–74. doi: 10.1007/s00586-019-06119-6 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Teraguchi M, Yim R, Cheung JP-Y, Samartzis D. The association of high-intensity zones on MRI and low back pain: a systematic review. Scoliosis Spinal Disord 2018; 13: 22. doi: 10.1186/s13013-018-0168-9 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Cheung JPY, Luk KDK. The relevance of high-intensity zones in degenerative disc disease. Int Orthop 2019; 43: 861–7. doi: 10.1007/s00264-018-4260-9 [DOI] [PubMed] [Google Scholar]
- 28.Rajakulasingam R, Saifuddin A. Focal nodular marrow hyperplasia: imaging features of 53 cases. Br J Radiol 2020; 93: 20200206. doi: 10.1259/bjr.20200206 [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Sasiponganan C, Yan K, Pezeshk P, Xi Y, Chhabra A. Advanced MR imaging of bone marrow: quantification of signal alterations on T1-weighted Dixon and T2-weighted Dixon sequences in red marrow, yellow marrow, and pathologic marrow lesions. Skeletal Radiol 2020; 49: 541–8. doi: 10.1007/s00256-019-03303-z [DOI] [PubMed] [Google Scholar]
- 30.Saifuddin A, Shafiq H, Malhotra K, Santiago R, Pressney I. Comparison of in-phase and opposed-phase T1W gradient echo and T2W fast spin echo Dixon chemical shift imaging for the assessment of non-neoplastic, benign neoplastic and malignant marrow lesions. Skeletal Radiol 2020; 6916 Nov 2020. doi: 10.1007/s00256-020-03663-x [DOI] [PubMed] [Google Scholar]
- 31.Y-J K, Lee E, Lee JW, Park CY, Cho J, Kang Y. Clinical validity of two different grading systems for lumbar central canal stenosis: Schizas and Lee classification systems. PLoS ONE 2020; 15: e0233633. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Pfirrmann CWA, Dora C, Schmid MR, Zanetti M, Hodler J, Boos N. Mr Image–based grading of lumbar nerve root compromise due to disk herniation: reliability study with surgical correlation. Radiology 2004; 230: 583–8. doi: 10.1148/radiol.2302021289 [DOI] [PubMed] [Google Scholar]
- 33.Hao D-J, Duan K, Liu T-J, Liu J-J, Wang W-T. Development and clinical application of grading and classification criteria of lumbar disc herniation. Medicine 2017; 96: e8676. doi: 10.1097/MD.0000000000008676 [DOI] [PMC free article] [PubMed] [Google Scholar]