SPECT in the management of patients with back pain and spondylolysis

Symptom-imaging correlation in lumbar spine pain

Lumbar spine MRI is associated with a high prevalence of morphological abnormalities in both symptomatic and asymptomatic individuals. A difficult challenge, therefore, is distinguishing the relevant findings causing symptoms from incidental findings. The accurate diagnosis of pain generator is important because misdiagnosis can negatively impact patient management and outcome. Spine physicians use clinical symptoms and signs to interpret lumbar spine MRI and make treatment decisions. Symptom-MRI correlation enables the targeted inspection of images for pain generator. Radiologists can also use clinical information to improve diagnostic confidence and the value of dictated reports. Because high-quality clinical information may be difficult to obtain, radiologists often generate lists of lumbar spine abnormalities that are otherwise difficult to rank as pain generators. Based on the literature review, this article attempts to distinguish the MRI abnormalities that may represent incidental findings from the abnormalities that are more commonly associated with lumbar spine-related symptoms.

The current role and future directions of imaging in failed back surgery syndrome patients: an educational review

BACKGROUND

Failed back surgery syndrome (FBSS) is an umbrella term referring to painful sensations experienced by patients after spinal surgery, mostly of neuropathic nature. Adequate treatment of FBSS is challenging, as its etiology is believed to be multifactorial and still not fully clarified. Accurate identification of the source of pain is difficult but pivotal to establish the most appropriate treatment strategy. Although the clinical utility of imaging in FBSS patients is still contentious, objective parameters are highly warranted to map different phenotypes of FBSS and tailor each subsequent therapy.

MAIN BODY

Since technological developments have weakened the applicability of prior research, this educational review outlined the recent evidence (i.e., from January 2005 onwards) after a systematic literature search. The state of the art on multiple imaging modalities in FBSS patients was reviewed. Future directions related to functional MRI and the development of imaging biomarkers have also been discussed.

CONCLUSION

Besides the fact that more imaging studies correlated with symptomatology in the postoperative setting are warranted, the current educational review outlined that contrast-enhanced MRI and MR neurography have been suggested as valuable imaging protocols to assess alterations in the spine of FBSS patients. The use of imaging biomarkers to study correlations between imaging features and symptomatology might hold future potential; however, more research is required before any promising hypotheses can be drawn.

Lumbar spondylolysis - Current concepts review

Lumbar pars interarticularis (PI) injury or spondylolysis occurs only in humans. This represents a stress fracture of the PI. Excessive loading in repetitive hyperextension is a significant risk factor and occurs most commonly at L5 followed by L4. It is bilateral in 80% of symptomatic cases but can be unilateral defect as well which runs a more benign course. Symptoms of low back pain relating to this lesion are more common in young athletes involved in trunk twisting sports. Like other stress fractures, the pain may come on abruptly or more insidiously over time and only related to certain activities. The pathologic progression starts with a stress reaction in the pars, progressing to an incomplete stress fracture, and then a complete pars fracture. Diagnosis is dependent on clinical examination and radiological imaging studies (plain radiography, computed tomography (CT) scans and magnetic resonance imaging (MRI) scans). Treatment is dependent on symptoms as well as radiographic stage of the lesion. Conservative management is the mainstay of treating early lesions. A comprehensive rehabilitation program incorporates core spinal stabilization exercises. Athletes should not return to sports until pain free. Professional sporting individuals are at increased risk of failure of resolution of symptoms that may require early surgical repair of the PI defect. Modified Buck's technique & pedicle screw-hook constructs for direct repair has a high success rate in patients who have persistent low back pain. Minimally invasive lumbar pars defect repair has given similar successful outcome with added advantage of minimizing muscle injury, preserving the adjacent joint and reduced hospital stay. Functional outcome is evaluated using the Visual Analogue Scale (VAS) for back pain, Oswestry Disability Index (ODI) and 36-Item Short-Form Health Survey (SF-36). Preoperative ODI and SF-36 physical component scores (PCS) are significant predictor of a good functional outcome.

Lumbosacral Spondylolysis and Spondylolisthesis

Repetitive stress on the lumbosacral spine during sporting activity places the athletic patient at risk of developing symptomatic pars defect. Clinical history, physical examination, and diagnostic imaging are important to distinguish spondylolysis from other causes of lower back pain. Early pars stress reaction can be identified with advanced imaging, before the development of cortical fracture or vertebral slip progression to spondylolisthesis. Conservative management is first-line for low-grade injury with surgical intervention indicated for refractory symptoms, severe spondylolisthesis, or considerable neurologic deficit. Prompt diagnosis and management of spondylolysis leads to good outcomes and return to competition for most athletes.

Return to Play in Adolescent Athletes With Symptomatic Spondylolysis Without Listhesis: A Meta-Analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVES

To assess return to play (RTP) rates in adolescent athletes with lumbar spondylolysis without spondylolisthesis treated conservatively or operatively.

METHODS

A review of Medline, EMBASE, and Cochrane Reviews was performed. The pooled results were performed by calculating the effect size based on the logit event rate. Studies were weighted by the inverse of the variance. Confidence intervals were reported at 95%. Heterogeneity was assessed using the Q statistic and I² value.

RESULTS

The initial literature search resulted in 724 articles, of which 29 were deemed relevant on abstract review. Overall, 11 studies provided data for 376 patients with a pars interarticularis defect. Return to athletic competition, based on logit event rate, was found to be statistically favored after both nonoperative and operative treatment (92.2% vs 90.3%). There was no heterogeneity noted among the studies reporting nonoperative treatment (Q value of 4.99 and I² value of 0). There was mild heterogeneity within the operative studies (Q value of 3.54 and I² value of 15.18).

CONCLUSIONS

Adolescent athletes RTP 92.2% of the time with nonoperative management, compared with 90.3% when treated operatively, though both treatment groups strongly favor RTP. As this is the first study to pool results of all relevant literature, it provides strong evidence to guide decision making and help manage expectations in this unique patient population.

The added value of SPECT/spiral CT in patients with equivocal bony metastasis from hepatocellular carcinoma

The aim of this study was to evaluate the incremental value provided by single-photon emission computed tomography (SPECT)/spiral computed tomography (CT) over SPECT alone for the evaluation of equivocal bone lesions in patients with hepatocellular carcinoma (HCC).

PATIENTS, METHODS

This was a retrospective study of 65 patients (61 men and 4 women; mean age, 53.1 ± 10.1 years; age range, 31-78 years) with HCC confirmed by pathology who underwent planar whole body scintigraphy and SPECT/CT. Each lesion was scored visually using a 5-point scale (0, negative; 1, benign; 2, likely benign; 3, likely bone metastasis; 4, bone metastasis). Lesions in which diagnostic confidence was scored as 3 or 4 were categorized into metastases.The final diagnosis of each lesion was based on pathological confirmation or follow-up by whole body scintigraphy and SPECT/spiral CT conducted two or more times. The diagnostic accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SPECT alone and SPECT/CT were computed.

RESULTS

The diagnostic accuracy, sensitivity, specificity, PPV, and NPV of SPECT alone were 78.4, 70.9%, 94.9%, 96.8% and 59.7%, respectively. Moreover, for agreement of SPECT alone and the final results, the kappa value was 0.567 (p < 0.001), which was considered to be moderate agreement. The diagnostic accuracy, sensitivity, specificity, PPV, and NPV of SPECT/CT were 99.2%, 100%, 97.4%, 98.9% and 100 %, respectively. Furthermore, for agreement of SPECT/CT and the final results, the kappa value was 0.981 (p < 0.001), which was considered to be nearly perfect agreement.

CONCLUSIONS

SPECT/spiral CT is more accurate and valuable than SPECT alone in the differential diagnosis of equivocal bone lesions in patients with HCC.

Radiological and Radionuclide Imaging of Degenerative Disease of the Facet Joints

The facet joint has been increasingly implicated as a potential source of lower back pain. Diagnosis can be challenging as there is not a direct correlation between facet joint disease and clinical or radiological features. The purpose of this article is to review the diagnosis, treatment, and current imaging modality options in the context of degenerative facet joint disease. We describe each modality in turn with a pictorial review using current evidence. Newer hybrid imaging techniques such as single photon emission computed tomography/computed tomography (SPECT/CT) provide additional information relative to the historic gold standard magnetic resonance imaging. The diagnostic benefits of SPECT/CT include precise localization and characterization of spinal lesions and improved diagnosis for lower back pain. It may have a role in selecting patients for local therapeutic injections, as well as guiding their location with increased precision.

Evaluation of neck pain with (18)F-NaF PET/CT

AIM

(18)F-Sodium fluoride ((18)F-NaF) PET/computed tomography (CT) has improved spatial resolution in the cervical spine compared with single photon emission computed tomography/CT techniques using traditional tracers. Limited data are available, however, on its effectiveness in the management of the symptomatic cervical spine, and the aim of this study was therefore to elucidate this issue.

PATIENTS AND METHODS

A retrospective study was carried out between April 2011 and April 2012. Across this period, 66 patients were referred to the department for the assessment of neck pain, of whom 58 were included in the study. (18)F-NaF was used as the tracer and images were acquired on an integrated PET/CT scanner. All studies were evaluated by either consultant nuclear medicine physicians or by a radiologist. Two consultant neurosurgeons correlated the imaging reports with the clinical data from the patient notes to give an overall impression as to how beneficial the test had been with regard to patient management.

RESULTS

In 49/58 (84.5%) cases, the (18)F-NaF PET/CT report was thought to have been clinically useful in patient management. In 9/58 (15.5%) cases, the report was thought not to have been clinically beneficial, generally because of high background vertebral uptake of (18)F-fluoride secondary to degenerative disease.

CONCLUSION

As our experience with (18)F-NaF PET/CT broadens, we believe that it will become an increasingly important tool in the evaluation and management of the symptomatic cervical spine.

Detection of pars injury by SPECT in patients younger than age 10 with low back pain

BACKGROUND

Evaluation of extension-based low back pain in young athletes with suspected pars injury may include a referral for skeletal single photon emission computed tomography (SPECT). However, the diagnostic yield of this technique in children with low back pain before the age of 10 years remains uncertain. We examined a series of consecutive SPECT scans to address this question.

MATERIALS AND METHODS

A retrospective review of department databases revealed 107 consecutive skeletal Tc-99m MDP SPECT scans performed between January 1, 2007 and December 31, 2009 in children less than 10 years of age. Of these, 72 studies were performed for a referral diagnosis of back pain. There were 43 girls (44 studies) and 28 boys (28 studies). The mean age was 7.2 years (range, 1.9 to 9.9 y). All SPECT scans were reviewed and positive findings documented. In addition, all available anatomic imaging, imaging reports (computed tomography, magnetic resonance, and x-ray) and clinical notes were reviewed, and results were compared with those of SPECT studies.

RESULTS

Of the 72 SPECT studies, 35 (49%) identified a focal area in the spine of abnormal increased uptake, with 17 in the region of the pars interarticularis. With additional imaging, 1 case was demonstrated not to be a pars injury (computed tomography showed a transverse process fracture) and 2 patients with negative SPECT scans were shown to have pars injuries that SPECT scan had not detected, for a total of 18 pars injuries (25%) in this cohort. Reported participation in gymnastics or football was related to pars injury (odds ratio 4.3, P=0.04).

CONCLUSIONS

Pars injury was found in 25% of children referred for SPECT scan with back pain below 10 years of age. SPECT scan was highly sensitive for this injury as well as in identifying other potential sites of pathology, and should be considered in the workup of persistent low back pain in young children.

LEVEL OF EVIDENCE

Level II, diagnostic study.

Is hybrid imaging (SPECT/CT) a useful adjunct in the management of suspected facet joints arthropathy?

PURPOSE

The purpose of this study was to assess the value of SPECT/CT imaging in patients with chronic spinal pain.

METHODS

This was a retrospective consecutive study. Patients with chronic neck or back pain from outpatient spinal clinics with clinical features raising the possibility of a facetogenic pain generator and non-conclusive MRI/CT findings were included. Imaging was performed on a dual-headed, hybrid SPECT/CT γ-camera with a low-dose CT transmission scan acquired after the SPECT study. SPECT/CT studies were viewed in the coronal, axial, and sagittal planes and in 3-dimensional mode. Descriptive statistical analysis was performed.

RESULTS

Seventy-two patients were included (37 females, 35 males, mean age of 53.9 years). There were 25 cervical spine scans and 49 lumbar spine scans. In the cervical spine group, 13 (52 %) patients had scintigraphically active cervical facet joint arthropathy and ten (36 %) had other pathology identified. Two thirds of patients diagnosed with facet joint arthropathy received steroid guided injections following their scans. In the lumbar spine group 34 (69.4 %) patients had scintigraphically active lumbar facet joint arthropathy and eight had other pathology identified. Twenty patients (58.8 %) diagnosed with facet joint arthropathy subsequently received steroid guided injections.

CONCLUSIONS

Hybrid SPECT/CT imaging identified potential pain generators in 92 % of cervical spine scans and 86 % of lumbar spine scans. The scan precisely localised SPECT positive facet joint targets in 65 % of the referral population and a clinical decision to inject was made in 60 % of these cases.

Single photon emission computerized tomography (SPECT) scan-positive facet joints and other spinal structures in a hospital-wide population with spinal pain

BACKGROUND CONTEXT

The current criterion standard for zygapophyseal (facet) joint pain diagnosis is placebo-controlled triple comparative local anesthetic facet joint or medial branch blocks. Single photon emission computerized tomography (SPECT) scanning is a less invasive modality that has been widely used in patients with spinal pain for the diagnosis of facet joint arthritis. Previous studies have shown that SPECT results correlate well with response to facet joints steroid injections.

PURPOSE

To evaluate the prevalence of SPECT scan-positive facet joints and other spinal areas in different age groups in a hospital-wide population with spinal pain.

STUDY DESIGN

Retrospective study.

METHODS

This study included 534 patients who underwent a SPECT scan for spinal pain over 7.5 years in our hospital. All referrals from all doctors for any cervical or lumbar spinal pain were included, and the results were reviewed.

RESULTS

A total of 486 patients (91.1%) had at least one positive abnormality on SPECT scan; 81.3% had increased uptake in different structures and regions of the spine. This included 42.8% increased uptake in the facet joint 29.8% in the vertebral bodies/end plates, and 5.9% in sacroiliac joints. The prevalence of increased uptake in the lumbosacral and cervical spine was 44% and 37%, respectively. When patients were divided into five age groups (below 40, 40-49, 50-59, 60-69, and 70 years and older), there was a significantly higher increased prevalence in advancing age groups.

CONCLUSIONS

In a hospital-wide population with spinal pain, there is a 42.88% prevalence of increased uptake in the facet joint on SPECT. The incidence increases significantly with advancing age. SPECT can play a role in investigating patients with spinal pain.

Streamlining the evaluation of low back pain in children

The workup of low back pain in children often results in overimaging so as not to miss organic back pain. The primary goal of this study was to identify which combination of imaging modalities provides the most sensitive and specific screening protocol for children with low back pain. Medical records from 100 consecutive patients between 2 and 18 years of age presenting with low back pain, without night pain or constitutional symptoms, were evaluated. A hyperextension test combined with a radiograph showed a negative predictive value of 0.81 and sensitivity of 0.90. The addition of a bone scan was highly effective in achieving good negative predictive value and sensitivity. Bone scans had perfect negative predictive value and sensitivity when symptom duration was less than 6 weeks. We identified a set of factors that is highly predictive for distinguishing organic back pain from mechanical back pain. Painless hyperextension combined with negative anteroposterior, lateral, and oblique lumbar radiographs and magnetic resonance images predicts mechanical back pain. For patients with nonneurologic back pain of less than 6 weeks duration, bone scan is the most useful screening test because it is accurate, accessible, inexpensive, and unlikely to require sedation.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Radiological findings and healing patterns of incomplete stress fractures of the pars interarticularis

OBJECTIVE

The objective was to retrospectively record the CT and MRI features and healing patterns of acute, incomplete stress fractures of the pars interarticularis.

METHOD

The CT scans of 156 adolescents referred with suspected pars interarticularis stress fractures were reviewed. Patients with incomplete (grade 2) pars fractures were included in the study. Fractures were assessed on CT according to vertebral level, location of cortical involvement and direction of fracture propagation. MRI was also performed in 72 of the 156 cases. MRI images of incomplete fractures were assessed for the presence of marrow oedema and cortical integrity. Fracture healing patterns were characterised on follow-up CT imaging.

RESULTS

Twenty-five incomplete fractures were identified in 23 patients on CT. All fractures involved the inferior or infero-medial cortex of the pars and propagated superiorly or superolaterally. Ninety-two percent of incomplete fractures demonstrated either complete or partial healing on follow-up imaging. Two (8%) cases progressed to complete fractures. Thirteen incomplete fractures in 11 patients confirmed on CT also had MRI, and 92% demonstrated oedema in the pars. Ten out of thirteen fractures (77%) showed a break in the infero-medial cortex with intact supero-lateral cortex, which correlated with the CT findings. MRI incorrectly graded one case as a complete (grade 3) fracture, and 2 cases as (grade 1) stress reaction. Six fractures had follow-up MRI, 67% showed partial or complete cortical healing, and the same number showed persistent marrow oedema.

CONCLUSIONS

Incomplete fracture of the pars interarticularis represents a stage of the evolution of a complete stress fracture. The direction of fracture propagation is consistent, and complete healing can be achieved in most cases with appropriate clinical management. CT best demonstrates fracture size and extent, and is the most appropriate modality for follow-up. MRI is limited in its ability to fully depict the cortical integrity of incomplete fractures of the pars, but the presence of marrow oedema on fat-saturated T2-weighted sequences is a useful means of detecting acute spondylolysis.

Acquired spondylolysis after implantation of a lumbar ProDisc II prosthesis: case report and review of the literature

STUDY DESIGN

A case of acquired lumbar spondylolysis following lumbar disc arthroplasty L5-S1 in an 40-year-old woman and review of the literature.

OBJECTIVES

To present and discuss a case of acquired lumbar spondylolysis after implantation of an artificial disc L5-S1 that may have impaired a good clinical result requiring additional posterior lumbar instrumentation and fusion in order to improve understanding of this condition and to propose an effective method of surgical management.

SUMMARY OF BACKGROUND DATA

Lumbar disc arthroplasty is a possible surgical option for patients with degenerative disc disease. Acquired spondylolysis is a rare but known complication of spinal fusion but has never been described as a consequence of mobile disc arthroplasty. The authors present the first case in the literature who developed this complication.

METHODS

A 40-year-old woman with severe osteochondrosis L5-S1 and discogenic lumbar back pain underwent implantation of an artificial disc. Surgery and postoperative course were uneventful and the patient improved significantly as for back pain and mobility. Eighteen months after surgery, the patient was again admitted to our outpatient clinic for back pain that had slowly increased over time.

RESULTS

The radiologic workup showed a new spondylolysis L5 without a spondylolisthesis. Because of unsuccessful conservative treatment, the patient underwent posterior lumbar instrumentation and fusion L5-S1, leading to a significant pain reduction and a good clinical outcome.

CONCLUSION

Spine surgeons should be aware of the possibility of lumbar disc arthroplasty to induce acquired spondylolysis impairing good clinical results.

Spondylolysis in active adolescents: expediting return to play

Spondylolysis is the most common identifiable cause of back pain in active adolescents, who often cope with the condition by hoping it will just go away. If the pain is prolonged or severe enough to bring them to a physician, an aggressive work-up for a specific diagnosis should be initiated. History and physical exam findings are suggestive but not diagnostic. Radiographs provide a first look, but other tests (eg, bone scans, CT, and MRI) are necessary to determine the metabolic activity and full extent of any lesions. Conservative therapy, including activity modification, physical therapy, and sometimes bracing, provides pain relief and focuses on return to full activity and prevention of recurrence.

The role of single photon emission computed tomography in bone imaging

Single photon emission computed tomography (SPECT) of the bone is the second most frequently performed SPECT examination in routine nuclear medicine practice, with cardiac SPECT being the most frequent. Compared with planar scintigraphy, SPECT increases image contrast and improves lesion detection and localization. Studies have documented the unique diagnostic information provided by SPECT, particularly for avascular necrosis of the femoral head, in patients with back pain, for the differential diagnosis between malignant and benign spinal lesions, in the detection of metastatic cancer in the spine, for the diagnosis of temporomandibular joint internal derangement, and for the evaluation of acute and chronic knee pain. Although less rigorously documented, SPECT is being increasingly used in all types of situations that demand more precise anatomic localization of abnormal tracer uptake. The effectiveness of bone SPECT increases with the selection of the proper collimator, which allows one to acquire adequate counts and minimize the patient-to-detector distance. Low-energy, ultrahigh-resolution or high-resolution collimation is preferred over all-purpose collimators. Multihead gamma cameras can increase the counts obtained or shorten acquisition time, making SPECT acquisitions more practical in busy departments and also increasing image quality compared with single-head cameras. Iterative reconstruction, with the use of ordered subsets estimation maximization, provides better quality images than classical filtered back projection algorithms. Three-dimensional image analysis often aids lesion localization.