Presence Of Bone Marrow Edema Research Articles

Reliability of the STIR sequence for acute type II odontoid fractures.

The STIR sequence is routinely used to assess acute traumatic osseous injury. Because the composition of the odontoid in older individuals may be altered with osteopenia and decreased vascularity, the STIR sequence may not accurately depict the acuity of an odontoid fracture. The purpose of this study was to evaluate the reliability of the STIR sequence to differentiate acute-versus-chronic type II odontoid fractures in older patients, particularly those with osteopenia. A retrospective review was performed for patients with type II odontoid fractures during a 10-year period with both CT and MR imaging performed within 24 hours of injury. Patients were paired with controls of similar ages and were grouped by age. The STIR images were evaluated in a blinded fashion for the presence of hyperintensity in the odontoid. Demographic and clinical characteristics were also recorded. Seventy-five patients with type II odontoid fracture and 75 healthy controls (mean and median age of 57 years) were identified. The sensitivity of STIR to detect fracture in the age group 57 years and older was significantly worse than that in the age group younger than 57 years (54% and 82%, respectively; P = .018). Older patients, particularly those with osteopenia, may have acute odontoid injuries without corresponding STIR hyperintensity. Additionally, interobserver agreement in STIR interpretation decreases with increasing patient age. As such, in this patient population, in which the presence of bone marrow edema as an indicator of fracture acuity may impact therapeutic decisions, correlation with CT findings and clinical history is crucial.

FRI0273 The presence of bone marrow edema at baseline magnetic resonance imaging and male sex may predict the development of radiographic sacroiliitis

ObjectivesRadiographic sacroiliitis is prerequisite for the diagnosis of ankylosing spondylitis (AS). Because of the development of unequivocal sacroiliitis may take about a decade, the diagnosis of AS is frequently delayed...

AB1282 Assessing active inflammation in sacroiliac joints (SIJ) in spondyloarthritis patients: No added value of gadolinium compared to short TAU inversion recovery (STIR) sequence

BackgroundMRI is used as a diagnostic tool to detect active disease of the sacroiliac joint. T1 weighted and STIR images are generally used and ASAS definition is based on bone...

OP0221 Is Site of Back Pain Related to Location of Inflammatory Lesions on MRI in Patients with Chronic Back Pain?

BackgroundIt is unclear whether location of inflammatory lesions (presence of bone marrow edema (BME)) is linked to site of pain symptomsObjectivesTo evaluate if localisation of back pain, as indicated by...

SAT0397 High bone turnover assessed by 18F-fluoride PET/CT in the spine of patients with ankylosing spondylitis: No redundancy to inflammatory lesions detected by whole body MRI

BackgroundThe current paradigm of radiographic progression in ankylosing spondylitis involves resolution of an inflammatory lesion and its replacement by fat tissue followed by cartilage metaplasia and endochondral ossification. However, syndesmophytes...

Magnetic resonance imaging of the sacroiliac joints in the early detection of spondyloarthritis: no added value of gadolinium compared with short tau inversion recovery sequence

To investigate the additional value of T1 fat-saturated after gadolinium (T1/Gd) compared with T1 and short tau inversion recovery (STIR) sequence in detecting active lesions of the SI joints typical of axial SpA (axSpA) in a prospective cohort study, the SpondyloArthritis Caught Early (SPACE) cohort, and to assess its influence on final MRI diagnosis of the SI joint (MRI-SIJ) based on the Assessment of Spondyloarthritis International Society (ASAS) definition of active sacroiliitis. Patients in the SPACE cohort received baseline and 3-month follow-up MRI-SIJ with coronal oblique T1, STIR and T1/Gd sequences. Bone marrow oedema (BME), capsulitis/enthesitis and synovitis and active sacroiliitis according to the ASAS definition were evaluated by three blinded readers. A total of 127 patients received an MRI-SIJ at baseline and 67 patients also received an MRI-SIJ at 3 months follow-up since the Gd protocol was added some months after the start of the SPACE project. Twenty-five of the 127 patients (19.7%) with a baseline MRI-SIJ and 14 of 67 patients (20.6%) with a follow-up MRI-SIJ presented BME on the STIR sequence sufficient to fulfill the ASAS definition for a positive MRI-SIJ. In eight patients, additional synovitis and/or capsulitis/enthesitis was observed; however, no additional BME was visualized on T1/Gd. One patient, without clinical diagnosis of axSpA, showed synovitis as an isolated finding. Synovitis and capsulitis/enthesitis are detectable with the administration of Gd. However, they are always observed in the presence of BME. Therefore T1 and STIR sequence alone are sufficient in the MRI assessment that, among others, is used for diagnosing patients with early axSpA.

Bone oedema on MRI is highly associated with low bone mineral density in patients with early inflammatory back pain: results from the DESIR cohort

ObjectivesTo assess bone mineral density (BMD) at lumbar spine and hip in a large cohort of patients with early inflammatory back pain (IBP) suggestive of axial spondyloarthritis (SpA), and to...

Metal-on-Metal Total Hip Arthroplasty: Do Symptoms Correlate with MR Imaging Findings?

To determine the prevalence of magnetic resonance (MR) imaging abnormalities after metal-on-metal total hip arthroplasty and to determine whether presence of symptoms correlates with findings at MR imaging. This HIPAA-compliant study was approved by the institutional review board, and informed consent was waived. MR imaging was performed with conventional sequences and a 1.5-T clinical imager in 192 hips (174 patients) evaluated during a 15-month period. Two observers retrospectively reviewed the images for the presence and size of pseudotumor, communication with the pseudocapsule, wall thickness, synovial hypertrophy, compartmentalization, solid components, foci of wall susceptibility, osteolysis, bone marrow edema, abductor muscle or tendon abnormality, and Anderson MR grade (normal, infection, or varying severity of metal-on-metal disease). These findings were compared between asymptomatic and symptomatic patients by using the Fisher exact test or the Wilcoxon-Mann-Whitney test, as appropriate. Prevalence of pseudotumors per patient and per hip was 69% (120 of 174 patients, 132 of 192 hips). Bone marrow edema (present in six asymptomatic patients and 19 patients with pain, P < .01) and tendon tearing (present in five asymptomatic patients and 13 patients with pain, P < .05) were predictors of pain. Presence of symptoms was not correlated with presence (P = .4151) or size of pseudotumors. Anderson MR grade binarized into normal versus abnormal showed moderate agreement between readers (κ = 0.439) but was also not correlated with symptoms (P = .6648). The presence of bone marrow edema and abductor tendon tears but not the presence or size of pseudotumor was associated with patient pain.

Reports of magnetic resonance images of the hip in patients with femoroacetabular impingement: is useful information provided to the orthopedic surgeon?

The aim of this study was twofold: (1) To evaluate the quality of radiology reports of MR imaging/arthrography (MRI/MRA) of the hip performed on symptomatic young adults with suspected femoroacetabular impingement (FAI); and (2) to assess if MRI/MRA reports provide relevant information for surgical decision-making. We evaluated 110 MRI/MRA reports provided by 73 radiologists from 42 institutions. The images were requested preoperatively in young adults who underwent hip-preserving surgery for treatment of FAI. The quality of reports was graded using Lee's method by two independent observers. The description of seven characteristics of the hip joint was scrutinized in order to assess if the reports contained relevant information for surgical decision-making. The quality of reports was Grade IIA in two cases (1.8 %), IIB in six (5.5 %), III in 60 (54.5 %), and IV in 42 (38.2 %). Relevant hip characteristics for the study of FAI were reported as follows: acetabular labrum (88.1 %), cartilage characteristics (69 %), morphology of the femoral head-neck junction (34.5 %), acetabular version (6.3 %), acetabular coverage (20.9 %), soft tissues description (82.7 %), and presence of bone marrow edema (80.9 %). The vast majority (91.8 %) of the reports described five or less relevant FAI characteristics. Most of the radiology reports of MRI/MRA of the hip performed on symptomatic young adults with FAI were of the highest quality. However, some characteristics believed to be important for surgical decision-making in this particular group of patients were frequently not described. The inclusion of these hip joint characteristics in the radiology reports may improve the usefulness of the information provided to the orthopedic surgeon.

Clinical and MRI results after microfracture of osteochondral lesions of the talus

Arthroscopic microfracture (AM) of osteochondral lesions of the talus is used to induce intrinsic refilling of the defect and reduce pain. The aim of this retrospective study was to investigate the clinical state after AM and the MRI outcome. A total of 22 patients [10 women, 12 men, 31years old (mean, 13-68 range)] treated for osteochondral lesions of the talus by AM were examined 2years (median) postoperatively and pre- and postoperative MRI results compared. Swelling/effusion, articular constriction, joint pain, and range of motion restriction were documented. Clinical state was evaluated using the AOFAS hindfoot score. MRI was used to assess the size of the defect, presence of bone marrow edema, cysts and effusion, thickness of repair tissue, and integrity of the cartilage. In all but six cases, the defect was located at the medial shoulder of the talus. The postoperative AOFAS score at follow-up was 87.5points (median 36-100points range). Seven patients were free of pain, 11 had "mild, occasional" pain, 1 "moderate daily", and 3 "severe, almost always present" pain (AOFAS). The defect volume was significantly reduced from 377mm(3) preoperatively (median, interquartile distance: 417mm(3)) to 249mm(3) postoperatively (median, IQD: 336mm(3), p=0.019, Wilcoxon). In 7 cases, the defect was completely filled, in 11 partially and in 4 only slightly. After AM of osteochondral lesions of the talus, 18 of 22 patients had no or mild, occasional pain at 2years follow-up. On MRI, the lesion volume had been reduced and filling with repair tissue was found.

Magnetic Resonance Imaging Identification of Rotator Cuff Retears After Repair

Background: Magnetic resonance imaging (MRI) is the most commonly used imaging modality to assess the rotator cuff. Currently, there are a limited number of studies assessing the interobserver and intraobserver reliability of MRI after rotator cuff repair. Hypothesis: Fellowship-trained orthopaedic shoulder surgeons will have good inter- and intraobserver agreement with regard to features of the repaired rotator cuff (repair integrity, fat content, muscle volume, number of tendons involved, tear size, and retract) on MRI. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Seven fellowship-trained orthopaedic shoulder surgeons reviewed 31 MRI scans from 31 shoulders from patients who had previous rotator cuff repair. The scans were evaluated for the following characteristics: rotator cuff repair status (full-thickness retear vs intact repair), tear location, tendon thickness, fatty infiltration, atrophy, number of tendons involved in retear, tendon retraction, status of the long head of the biceps tendon, and bone marrow edema in the humeral head. Surgeons were asked to review images at 2 separate time points approximately 9 months apart and complete an evaluation form for each scan at each time point. Multirater kappa (κ) statistics were used to assess inter- and intraobserver reliability. Results: The interobserver agreement was highest (80%, κ = 0.60) for identifying full-thickness retears, tendon retear retraction (64%, κ = 0.45), and cysts in the greater tuberosity (72%, κ = 0.43). All other variables were found to have fair to poor agreement. The worst interobserver agreement was associated with identifying rotator cuff footprint coverage (47%, κ = −0.21) and tendon signal intensity (29%, κ = −0.01). The mean intraobserver reproducibility was also highest (77%-90%, κ = 0.71) for full-thickness retears, quality of the supraspinatus (47%-83%, κ = 0.52), tears of the long head of the biceps tendon (58%-94%, κ = 0.49), presence of bone marrow edema in the humeral head (63%-87%, κ = 0.48), cysts in the greater tuberosity (70%-83%, κ = 0.47), signal in the long head of the biceps tendon (60%-80%, κ = 0.43), and quality of the infraspinatus (37-90%, κ = 0.43). The worst intraobserver reproducibility was found in identification of the location of bone marrow edema (22%-83%, κ = −0.03). Conclusion: The results of this study indicate that there is substantial variability when evaluating MRI scans after rotator cuff repair. Intact rotator cuff repairs or full-thickness retears can be identified with moderate reliability. These findings indicate that additional imaging modalities may be needed for accurate assessment of the repaired rotator cuff.

A prospective study on MRI findings and prognostic factors in athletes with MTSS

In medial tibial stress syndrome (MTSS) bone marrow and periosteal edema of the tibia on the magnetic resonance imaging (MRI) is frequently reported. The relationship between these MRI findings and recovery has not been previously studied. This prospective study describes MRI findings of 52 athletes with MTSS. Baseline characteristics were recorded and recovery was related to these parameters and MRI findings to examine for prognostic factors. Results showed that 43.5% of the symptomatic legs showed bone marrow or periosteal edema. Absence of periosteal and bone marrow edema on MRI was associated with longer recovery (P = 0.033 and P = 0.013). A clinical scoring system for sports activity (SARS score) was significantly higher in the presence of bone marrow edema (P = 0.027). When clinical scoring systems (SARS score and the Lower Extremity Functional Scale) were combined in a model, time to recovery could be predicted substantially (explaining 54% of variance, P = 0.006). In conclusion, in athletes with MTSS, bone marrow or periosteal edema is seen on MRI in 43,5% of the symptomatic legs. Furthermore, periosteal and bone marrow edema on MRI and clinical scoring systems are prognostic factors. Future studies should focus on MRI findings in symptomatic MTSS and compare these with a matched control group.

High bone turnover assessed by 18F-fluoride PET/CT in the spine and sacroiliac joints of patients with ankylosing spondylitis: comparison with inflammatory lesions detected by whole body MRI

BackgroundThis study compares the frequency and distribution of increased activity on 18 F-fluoride PET/CT with the presence of bone marrow edema on whole-body MR imaging in the spine and sacroiliac joints (SIJ) of patients with active ankylosing spondylitis (AS).MethodsTen patients (6 men and 4 women), between 30 and 58 years old (median 44) with active AS, were prospectively examined with both whole-body MRI and 18 F-fluoride PET/CT. Patients fulfilled modified NY criteria and had a Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) of at least 4. Increased radiotracer uptake in PET/CT and bone marrow edema in whole-body MRI of spine and SIJ was evaluated independently by two blinded observers for each modality. Kappa statistics were used to compare interobserver agreement as well as scores of consensus reading of the two imaging modalities.ResultsAnalysis of interobserver agreement for PET/CT yielded a kappa value of 0.68 for spinal lesions and of 0.88 for SIJ lesions. The corresponding kappa values for the MRI modality were 0.64 and 0.93, respectively. More spinal lesions were detected by MRI in comparison to PET/CT (68 vs. 38), whereas a similar number of SIJ quadrants scored positive in both modalities (19 vs. 17). Analysis of agreement of lesion detection between both imaging modalities yielded a kappa value of only 0.25 for spinal lesions and of 0.64 for SIJ lesions.ConclusionIncreased 18 F-fluoride uptake in PET/CT is only modestly associated with bone marrow edema on MRI in the spine and SIJ of patients with AS, suggesting different aspects of bone involvement in AS.

Modulation of the intramedullary pressure responses by calcium dobesilate in a rabbit knee model of osteoarthritis

Background and purpose The presence of bone marrow edema in patients with osteoarthritis is associated with pain and disease progression. Management of bone edema with the synthetic prostacyclin iloprost may be complicated by side effects. Calcium dobesilate, a treatment for chronic venous disease, shares some pharmacological actions with iloprost but appears to be better tolerated. Anecdotal reports have suggested that calcium dobesilate may be useful for medical management of osteoarthritis, possibly by reducing bone marrow edema, and this study was performed to investigate possible benefits of treatment.Methods The effects of a 6-week period of oral calcium dobesilate administration on tibial intramedullary pressure dynamics and physical joint characteristics were evaluated in 20 rabbits with unilaterally induced knee osteoarthritis that were randomly allocated to either a treatment group or a placebo control group. Treatment or placebo started 8 weeks after induction of osteoarthritis, and was followed by a 4-week washout period.Results Calcium dobesilate did not affect joint thickness or range of motion, nor individual pressure measurements, compared to placebo. Pressure ranges in the operated limb were greater than in the intact limb after 8 weeks, and approached those of the intact limb after 6 weeks of treatment with calcium dobesilate but not with placebo. Inter-limb differences were lower (p = 0.02) in the dobesilate group following the washout period.Interpretation Calcium dobesilate had a detectable effect on pressure dynamics in the subchondral bone of osteoarthritic joints in this model. The significance of these effects for pain and function should be established.

Stable or unstable tear of the anterior cruciate ligament of the knee: an MR diagnosis?

To determine the usefulness of magnetic resonance (MR) imaging to distinguish stable from unstable tears of the anterior cruciate ligament (ACL) of the knee. MR images of 97 patients with surgically confirmed ACL tear were retrospectively reviewed. According to arthroscopic and clinical examination, these patients had 36 stable and 61 unstable (9 partial and 52 complete) ACL tears. MR images were interpreted by two blinded reviewers and scored with respect to previously reported primary and secondary MR signs of ACL injury. Based on a comprehensive assessment of all the MR findings, ACLs were categorized as being stable or unstable. MR accuracy was calculated considering only primary MR signs and considering both primary and secondary MR signs of ACL injury, separately. Accuracy of each individual primary and secondary MR sign was calculated. Considering only primary MR signs, sensitivity, specificity, and accuracy of MR were 77, 92, and 82%, respectively. Considering both primary and secondary MR signs, sensitivity, specificity, and accuracy of MR were 59, 81, and 67%, respectively. Of all MR signs, discontinuity and abnormal orientation had highest test accuracy (79 and 87%, respectively). Anterior tibial translation, uncovering of the posterior horn of the lateral meniscus, and hyperbuckled PCL were only seen in unstable ACLs (specificity 100%), but these secondary findings had low sensitivity (23%). Bone contusion around the lateral knee compartment was seen in both unstable and stable ACLs (accuracy 64%). Previously reported MR imaging signs do not allow accurate distinction between clinically stable and unstable ACL injuries. Anterior tibial translation, uncovering of the posterior horn of the lateral meniscus, and hyperbuckled PCL, if present, are helpful signs in the diagnosis of an unstable tear. The presence of bone marrow edema around the lateral knee compartment is not predictive of ACL insufficiency.

Radiologic findings of adult pelvis and appendicular skeletal Langerhans cell histiocytosis in nine patients

The purpose of this article was to evaluate the radiologic findings of adult pelvis and appendicular skeletal Langerhans cell histiocytosis (LCH), emphasizing the CT and MR findings. The images of nine patients with pathologically proven LCH (five men and four women; mean age, 37.11 years) were retrospectively reviewed. Imaging analysis was confined to the long and flat bones. CT scans were performed in five patients and MR imaging was performed in eight. Images were assessed for the following features on CT and MRI: the location and number of lesions; the presence of cortical destruction, endosteal scalloping, and a periosteal reaction on CT or MRI; the margin of soft tissue masses, the presence of bone marrow edema, and a "budding" appearance on MRI; and the presence of sclerotic margins or septations on CT. The involved skeletal sites were the pelvis (seven), femurs (five), humeri (two), tibias (two), fibula (one), clavicle (one), scapula (one), and sternum (one). Endosteal scalloping, a periosteal reaction, and a budding appearance were common on MRI or CT images. Although cortical destruction and the soft tissue lesion formation were rare, soft tissue masses had well-defined margins. Endosteal scalloping and a budding appearance with a periosteal reaction on CT and MRI may be helpful signs for differentiation of LCH from malignant tumors in adults.

La “poussée” dolorosa acuta dell’artrosi di ginocchio con concomitante edema midollare: efficacia del trattamento con bisfosfonati parenterali

Knee osteoarthritis is a frequent clinical condition in the elderly population, characterized by chronic low or mild pain with the occasional occurrence of severe pain. Acute pain in knee osteoarthritis is often related to the presence of bone marrow edema on magnetic resonance (MR). Bisphosphonates are reported to be effective in the treatment of pain in clinical conditions characterized by bone marrow edema on MR imaging, such as transient osteoporosis of the hip, reflex sympathetic dystrophic syndrome and sacroileitis in spondyloarthritis. We report on the case of a 75-year-old woman affected by knee osteoarthritis with acute pain, refractory to conventional therapies with NSAIDs and intra-articular hyaluronic acid and corticosteroids. MR imaging showed an extensive signal alteration of the medial compartment of the right knee, hyperintense on T1-weighted and hypointense on T2-weighted and STIR sequences, suggestive for the presence of bone marrow edema. She was treated with intravenous pamidronate at the dosage of 60 mg, administered four times, once every third day. She reported a significant pain reduction in two weeks and complete pain relief in two months. MR performed two months later showed bone marrow edema disappearance. Our experience suggests that a short course of pamidronate could be effective in the treatment of acute pain related to symptomatic knee osteoarthritis with bone marrow edema, and it could be considered as an innovative therapeutic approach to pain refractory to standard therapies.

Os naviculare: the multi-ossicle configuration of a normal variant

To describe the multi-ossicle appearance of the os naviculare on MRI and CT examinations and to correlate this appearance with the published classification of this well-known skeletal variant. We retrospectively reviewed 148 patients, examined within a 2-year period (170 CT and MRI studies of the foot-ankle), for the presence of os naviculare. This variant was classified according to a widely used system (type I, II, III). In addition, each navicular variant was further reclassified according to the presence of one or more ossicles. The presence of bone marrow edema was also recorded. Accessory navicular bone was identified in 34 cases (20%) of the 170 exams. It was detected in 14 male and 14 female patients with the following incidence: 11.15% type I (19 cases), 4.11% type II (7 cases) and 4.74% type III (8 cases). In six cases the location was bilateral. Among patients with os naviculare, a multi-ossicle appearance with a total incidence of 14.7% (8.8% two ossicle configuration and 5.9% three ossicle configuration) was observed. In two type II cases studied with MRI, there was bone marrow edema suggesting a painful pseudarthrosis. The presence of multiple accessory navicular bone ossicles, not previously described with cross-sectional imaging, is reported herein. The pathogenesis and clinical relevance of this uncommon variant needs to be elucidated with further studies.

Matrix-induced autologous chondrocyte implantation of the knee: mid-term and long-term follow-up by MR arthrography

To define magnetic resonance (MR) arthrography imaging findings of matrix-induced autologous chondrocyte implantation (MACI) grafts of the knee in order to describe implant behaviour and to compare findings with validated clinical scores 30 and 60 months after MACI implant. Thirteen patients were recruited (10 male, 3 female) with a total number of 15 chondral lesions. Each patient underwent an MACI procedure and MR arthrography 30 and 60 months after surgery. MR arthrography was performed using a dedicated coil with a 1.5-Tesla unit. The status of the chondral implant was evaluated with the modified MOCART scoring scale. The lining of the implant, the integration to the border zone, the surface and structure of the repaired tissue were assessed, and the presence of bone marrow oedema and effusion was evaluated. For clinical assessment, the Cincinnati score was used. At 60 months, the abnormality showed worsening in 1 out of 15 cases. Integration showed improvement in 3 out of 15 cases, and worsening in 3 out of 15 cases. Two surfaces of the implant showed further deterioration at 60 months, and 1 afflicted implant fully recovered after the same time interval. Implant contrast enhancement at 30 months was seen in 2 out of 15 cases, 1 of which recovered at 60 months. According to the MOCART score, 4 cases were rated 68.4 out of 75 at 30 months and 65 out of 75 at 60 months. The mean clinical score decreased from 8.6 out of 10 at 30 months to 8.1 out of 10 at 60 months. Magnetic resonance arthrography improved the evaluation of implants and facilitated the characterisation of MACI integration with contiguous tissues. The follow-up showed significant changes in MACI, even at 60 months, allowing for useful long-term MR evaluations.

Lumbar spondylolysis: a review

Spondylolysis is an osseous defect of the pars interarticularis, thought to be a developmental or acquired stress fracture secondary to chronic low-grade trauma. It is encountered most frequently in adolescents, most commonly involving the lower lumbar spine, with particularly high prevalence among athletes involved in certain sports or activities. Spondylolysis can be asymptomatic or can be a cause of spine instability, back pain, and radiculopathy. The biomechanics and pathophysiology of spondylolysis are complex and debated. Imaging is utilized to detect spondylolysis, distinguish acute and active lesions from chronic inactive non-union, help establish prognosis, guide treatment, and to assess bony healing. Radiography with satisfactory technical quality can often demonstrate a pars defect. Multislice CT with multiplanar reformats is the most accurate modality for detecting the bony defect and may also be used for assessment of osseous healing; however, as with radiographs, it is not sensitive for detection of the early edematous stress response without a fracture line and exposes the patient to ionizing radiation. Magnetic resonance (MR) imaging should be used as the primary investigation for adolescents with back pain and suspected stress reactions of the lumbar pars interarticularis. Several imaging pitfalls render MR imaging less sensitive than CT for directly visualizing the pars defects (regional degenerative changes and sclerosis). Nevertheless, the presence of bone marrow edema on fluid-sensitive images is an important early finding that may suggest stress response without a visible fracture line. Moreover, MR is the imaging modality of choice for identifying associated nerve root compression. Single-photon emission computed tomography (SPECT) use is limited by a high rate of false-positive and false-negative results and by considerable ionizing radiation exposure. In this article, we provide a review of the current concepts regarding spondylolysis, its epidemiology, pathogenesis, and general treatment guidelines, as well as a detailed review and discussion of the imaging principles for the diagnosis and follow-up of this condition.