Diagnostic accuracy of dual-energy computed tomography in bone marrow edema with vertebral compression fractures: A meta -analysis

Updates on the Applications of Spectral Computed Tomography for Musculoskeletal Imaging

Spectral CT represents a novel imaging approach that can noninvasively visualize, quantify, and characterize many musculoskeletal pathologies. This modality has revolutionized the field of radiology by capturing CT attenuation data across multiple energy levels and offering superior tissue characterization while potentially minimizing radiation exposure compared to traditional enhanced CT scans. Despite MRI being the preferred imaging method for many musculoskeletal conditions, it is not viable for some patients. Moreover, this technique is time-consuming, costly, and has limited availability in many healthcare settings. Thus, spectral CT has a considerable role in improving the diagnosis, characterization, and treatment of gout, inflammatory arthropathies, degenerative disc disease, osteoporosis, occult fractures, malignancies, ligamentous injuries, and other bone-marrow pathologies. This comprehensive review will delve into the diverse capabilities of dual-energy CT, a subset of spectral CT, in addressing these musculoskeletal conditions and explore potential future avenues for its integration into clinical practice.

Post-mortem feasibility of dual-energy computed tomography in the detection of bone edema-like lesions in the equine foot: a proof of concept

Introduction

In this proof-of-concept study, the post-mortem feasibility of dual-energy computed tomography (DECT) in the detection of bone edema-like lesions in the equine foot is described in agreement with the gold standard imaging technique, which is magnetic resonance imaging (MRI).

Methods

A total of five equine cadaver feet were studied, of which two were pathological and three were within normal limits and served as references. A low-field MRI of each foot was performed, followed by a DECT acquisition. Multiplanar reformations of DECT virtual non-calcium images were compared with MRI for the detection of bone edema-like lesions. A gross post-mortem was performed, and histopathologic samples were obtained of the navicular and/or distal phalanx of the two feet selected based on pathology and one reference foot.

Results

On DECT virtual non-calcium imaging, the two pathological feet showed diffuse increased attenuation corresponding with bone edema-like lesions, whereas the three reference feet were considered normal. These findings were in agreement with the findings on the MRI. Histopathology of the two pathologic feet showed abnormalities in line with bone edema-like lesions. Histopathology of the reference foot was normal.

Conclusion

DECT virtual non-calcium imaging can be a valuable diagnostic tool in the diagnosis of bone edema-like lesions in the equine foot. Further examination of DECT in equine diagnostic imaging is warranted in a larger cohort, different locations, and alive animals.

Detection of bone marrow edema in differential diagnoses of odontogenic cysts using dual-energy computed tomography

PURPOSE

In this study, we prospectively investigated the relationship between bone marrow edema (BME) and odontogenic cysts and explored the possibility of using dual-energy computed tomography (DECT) as an auxiliary tool for the diagnosis of odontogenic cysts.

METHODS

This cross-sectional study included 73 patients who underwent the DECT scan and surgery for odontogenic cysts or odontogenic tumors. The virtual noncalcium (VNCa) computed tomography (CT) values and CT values were measured at several sites. The predictor variable was diagnosis, and the other variables included age, sex, and sites. The primary outcome was VNCa CT value. Variables were tested using the chi-square test or the Kruskal-Wallis test. The VNCa CT and CT values were tested using the Scheffe test for multiple comparisons. All variables were analyzed as independent variables affecting the VNCa CT values around the lesion in the multiple regression analysis.

RESULT

There were 35 men and 38 women. The mean patient age was 50.0 ± 19.5 years (range: 8-86). The VNCa CT values (- 6.2 ± 34.3) around the lesion in patients with RCs were significantly higher than those in patients with dentigerous cysts (- 44.4 ± 28.6) and odontogenic keratocysts (- 67.3 ± 19.5). In multiple regression analysis, the VNCa CT values around the lesion showed a significant positive correlation with histological results (regression coefficient: - 0.605, P < 0.001).

CONCLUSION

The presence of BME is associated with radicular cysts, and DECT can be used as an auxiliary tool for radicular cyst diagnosis.

Traumatic bone marrow lesions in dual-energy computed tomography

Traumatic bone marrow lesions (TBMLs) are considered to represent a range of concealed bone injuries, including haemorrhage, infarction, and localised oedema caused by trabecular microfracture occurring in the cancellous bone. If TBMLs are not managed timeously, they potentially cause a series of complications that can lead to irreversible morbidity and prolonged recovery time. This article reviews interesting image findings of bone marrow lesions in dual-energy computed tomography (DECT). In addition to combining the benefits of traditional CT imaging, DECT also reveals and identifies various structures using diverse attenuation characteristics of different radiographic spectra. Therefore, DECT has the capacity to detect TBMLs, which have traditionally been diagnosed using MRI. Through evaluating DECT virtual non-calcium maps, the detection of TBMLs is rendered easier and more efficient in some acute accidents.

Utility of dual energy computed tomography in the evaluation of infiltrative skeletal lesions and metastasis: a literature review

Computed tomography (CT) is routinely used to diagnose and evaluate metastatic lesions in oncology. CT alone suffers from lack of sensitivity, especially for skeletal lesions in the bone marrow and lesions that have similar attenuation profiles to surrounding bone. Magnetic resonance imaging and nuclear medicine imaging remain the gold standard in evaluating skeletal lesions. However, compared to CT, these modalities are not as widely available or suitable for all patients. Dual energy computed tomography (DECT) exploits variations in linear attenuation coefficient of materials at different photon energy levels to reconstruct images based on material composition. DECT in musculoskeletal imaging is used in the imaging of crystal arthropathy and detecting subtle fractures, but it is not broadly utilized in evaluating infiltrative skeletal lesions. Malignant skeletal lesions have different tissue and molecular compositions compared to normal bone. DECT may exploit these physical differences to delineate infiltrative skeletal lesions from surrounding bone better than conventional monoenergetic CT. Studies so far have examined the utility of DECT in evaluating skeletal metastases, multiple myeloma lesions, pathologic fractures, and performing image-guided biopsies with promising results. These studies were mostly retrospective analyses and case reports containing small samples sizes. As DECT becomes more widely used clinically and more scientific studies evaluating the performance of DECT are published, DECT may eventually become an important modality in the work-up of infiltrative skeletal lesions. It may even challenge MRI and nuclear medicine because of relatively faster scanning times and ease of access.

Management of vertebral compression fractures: the role of dual-energy CT in clinical practice

PURPOSE

To evaluate the role of dual-energy computed tomography (DECT) in the management of vertebral compression fractures in clinical practice.

MATERIALS AND METHODS

This retrospective IRB-approved study included 497 consecutive patients with suspected acute vertebral fractures, imaged either by DECT (group 1) or MRI (group 2) before vertebroplasty. The site, number and type of fractures at imaging findings, and clinical outcome based on any change in pain (DELTA-VAS), before (VAS-pre) and after treatment (VAS-post), were determined and compared. Two radiologists evaluated DECT and MRI images (15 and 5 years of experience, respectively), and inter-observer and intra-observer agreement were calculated using k statistics.

RESULTS

Both in the control group (n = 124) and in the group of patients treated by vertebroplasty (n = 373), the clinical outcome was not influenced by the imaging approach adopted, with a DELTA-VAS of 5.45 and 6.42 in the DECT group and 5.12 and 6.65 in the MRI group (p = 0.326; p = 0.44). In the group of treated patients, sex, age, lumbar fractures, multiple fractures, previous fractures, Genant grade, involvement of anterior apex or superior endplates, and increased spinal curvatures were similar (p = ns); however, dorsal fractures were more prevalent in group 1 (p = 0.0197). Before treatment, the mean VAS-pre was 8.74 in group 1 (DECT) and 8.65 in group 2 (MRI) (p = 0.301), whereas after treatment, the mean VAS-post value was 2.32 in group 1 (p = 0.0001), and 2.00 in group 2 (p = 0.0001). The DELTA-VAS was 6.42 in the group of patients imaged using DECT and 6.65 in the group imaged using MRI (p = 0.326). Inter-observer and intra-observer agreement were 0.85 and 0.89 for DECT, and 0.88 and 0.91 for MRI, respectively.

CONCLUSION

The outcome of vertebral compression fracture management was no different between the two groups of patients studied.

Virtual non-calcium dual-energy CT: clinical applications

Dual-energy CT (DECT) has emerged into clinical routine as an imaging technique with unique postprocessing utilities that improve the evaluation of different body areas. The virtual non-calcium (VNCa) reconstruction algorithm has shown beneficial effects on the depiction of bone marrow pathologies such as bone marrow edema. Its main advantage is the ability to substantially increase the image contrast of structures that are usually covered with calcium mineral, such as calcified vessels or bone marrow, and to depict a large number of traumatic, inflammatory, infiltrative, and degenerative disorders affecting either the spine or the appendicular skeleton. Therefore, VNCa imaging represents another step forward for DECT to image conditions and disorders that usually require the use of more expensive and time-consuming techniques such as magnetic resonance imaging, positron emission tomography/CT, or bone scintigraphy. The aim of this review article is to explain the technical background of VNCa imaging, showcase its applicability in the different body regions, and provide an updated outlook on the clinical impact of this technique, which goes beyond the sole improvement in image quality.

Dual-Energy Computed Tomography in Spine Fractures: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of this study was to perform a systematic literature review and meta-analysis to evaluate the sensitivity, specificity, and accuracy of dual-energy computed tomography (DE-CT) of bone marrow edema and disc edema in spine injuries.In vertebral injuries, prompt diagnosis is essential to avoid any delays in treatment. Conventional radiography may only reveal indirect signs of fractures, such as when it is displaced. Therefore, to detect the presence of bone marrow or disc edemas, adjunctive tools are required, such as magnetic resonance imaging (MRI) or DE-CT.

METHODS

Search terms included ((DECT) OR (DE-CT) OR (dual-energy CT) OR "Dual energy CT" OR (dual-energy computed tomography) OR (dual energy computed tomography)) AND ((spine) OR (vertebral)), and the PubMed, EMBASE, and MEDLINE databases and the Cochrane Library and Google were used. We found 1233 articles on our preliminary search, but only 13 articles met all criteria. Data were extracted to calculate the pooled sensitivity, specificity, and diagnostic odds ratio for analysis using R software.

RESULTS

Within the 13 studies, 515 patients, 3335 vertebrae, and 926 acute fractures (27.8%) defined by MRI were included. The largest cohort included 76 patients with 774 vertebrae. In 12 publications, MRI was reported for comparison. For DE-CT, the overall sensitivity was 86.2% with a specificity of 91.2% and accuracy of 89.3%. Furthermore, 5 studies reported the accuracy of CT with an overall sensitivity of 81.3%, specificity of 80.7%, and accuracy with 80.9%. Significant differences were found for specificity (P < .001) and accuracy (P = .023). However, significant interobserver differences were reported.

CONCLUSIONS

DE-CT seems to be a promising diagnostic tool to detect bone marrow and disc edemas, which can potentially replace the current gold standard, the MRI.

LEVEL OF EVIDENCE

2.

CLINICAL RELEVANCE

This study shows that DE-CT seems to be a promising diagnostic tool with an accuracy of 89.3%.

Diagnostic accuracy of dual-energy CT for detecting bone marrow edema in patients with acute knee injuries: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis evaluated the diagnostic accuracy of dual-energy CT (DECT) for detecting bone marrow edema (BME) in adult patients with acute knee injuries.

METHODS

A systematic review of MEDLINE, EMBASE, Scopus, the Cochrane Library, and gray literature was performed from inception to January 31, 2020, using PRISMA-DTA guidelines. The review included studies assessing the diagnostic accuracy of DECT for detecting BME in at least 10 adult patients with acute knee injuries and with an MRI reference standard. Study details were independently extracted by two reviewers. Meta-analysis was performed using a bivariate mixed-effects regression model with subgroup analysis performed to evaluate for sources of variability. Risk of bias (ROB) was evaluated using the QUADAS-2 tool.

RESULTS

Eight studies evaluating 267 patients between the ages of 25-54 with acute knee injuries undergoing DECT and MRI were included in analysis. Summary sensitivity, specificity, and AUROC values for BME were 84% (95% confidence interval (CI) 74-91%), 96% (95% CI 93-98%), and 0.97 (95% CI 0.95-0.98), respectively. Bone-based characterization was found to have lower specificity than region-based characterization (83% (57-95%) versus 97 (96-98%), p < 0.05), but no difference in sensitivity. No other statistical differences were identified amongst study subgroups to account for presumed variability amongst studies. Most studies were rated low risk for bias and applicability concerns.

CONCLUSION

DECT is specific and accurate for detecting BME in adult patients with acute knee injuries and can be used as an alternative to MRI, particularly when MRI is contraindicated or unavailable.

Dual-Energy Computed Tomography Virtual Noncalcium Technique in Diagnosing Osteoporosis: Correlation With Quantitative Computed Tomography

OBJECTIVE

The aim of this study was to evaluate dual-energy computed tomography (CT) virtual noncalcium (VNCa) technique as a means of quantifying osteoporosis.

METHODS

Dual-energy CT scans were obtained prospectively, targeting lumbar regions of 55 patients with chronic low back pain. A standard quantitative CT (QCT) phantom was positioned at the waist during each procedure, using proprietary software (QCT Pro; Mindways, Tex) to measure bone mineral density (BMD) in each vertebral body. Vendor dual-energy analytic software was altered with a specially modified configuration file to produce a "Virtual Non Calcium" or "VNCa" output, as such output variables were remapped to produce the following calcium values rather than iodine, yielding the following QCT parameters: CT value of calcium (originally "contrast media" [CM]), CT value of mixed energy imaging (regular CT value [rCT]), calcium density (originally "contrast agent density" [CaD]), and fat fraction (FF). Pearson test served to assess correlations between BMD and these parameters. Multiple linear regression analysis was applied to construct an equation for generating regressive BMD (rBMD) values. In gauging diagnostic accuracies, the criterion-standard BMD cutoff point (<80 mg/cm3) was adopted for QCT, whereas the rBMD threshold was defined by receiver operating characteristic curve.

RESULTS

Contrast media, rCT, CaD, and FF values (reflecting CT value of calcium, regular CT value, calcium density, and fat fraction, respectively) significantly correlated with BMD (r values: 0.885, 0.947, 0.877, and 0.492, respectively; all P < 0.01). Contrast media, CaD, and FF showed independent associations with BMD; the regressive equation was formulated as follows: rBMD = 54.82 - 0.19 × CM + 20.03 × CaD - 1.24 × FF. The area under the curve of rBMD in diagnosing osteoporosis was 0.966 ± 0.009 (P < 0.01). At an rBMD threshold of less than 81.94 mg/cm3, sensitivity and specificity were 90.0% and 92.0%, respectively.

CONCLUSIONS

Dual-energy CT VNCa technique may constitute a valid alternative method for quantifying the mineral content and marrow fat composition of bone in diagnostic assessments of osteoporosis.

Dual energy computed tomography evaluation of skeletal traumas

Skeletal traumas are among the most common routine challenges faced by Emergency Radiologists, in particular in case of radiographically occult nondisplaced fractures or in case of soft tissue injuries. With the development of Dual Energy Computed Tomography (DECT) technology, new post-processing applications have gained a useful diagnostic role in many fields of musculoskeletal imaging including acute skeletal trauma imaging. In addition to conventional CT images, DECT allows for the generation of virtual calcium-suppressed images subtracting calcium from unenhanced CT images based on the fact that material attenuation varies at different energy levels. In this way, virtual-non-calcium (VNC) images can precisely characterize traumatic bone marrow edema in both axial and appendicular skeleton, facilitating prompt clinical decision, especially when magnetic resonance method is contraindicated or unavailable. Other DECT emerging applications in the trauma setting include metal artifact reduction and collagen mapping for the evaluation of injuries affecting ligament, tendon, and intervertebral disk. This review focuses on the basic principles of DECT and related post-processing algorithms, highlighting the current advantages and limitations of these new imaging advances in the Emergency Department related to skeletal traumas.

Diagnostic accuracy of dual-energy CT for the detection of bone marrow edema in the appendicular skeleton: a systematic review and meta-analysis

OBJECTIVES

This meta-analysis evaluated the diagnostic accuracy of dual-energy CT (DECT) for detecting bone marrow edema (BME) in the appendicular skeleton.

METHODS

A systematic review of MEDLINE, EMBASE, Scopus, the Cochrane Library, and gray literature from inception through January 31, 2020, was performed. Original articles with > 10 patients evaluating the accuracy of DECT for detecting BME in the appendicular skeleton with a reference standard of MRI and/or clinical follow-up were included. Study details were independently extracted by two reviewers. Meta-analysis was performed using a bivariate random-effects model with multivariable meta-regression. Risk of bias (RoB) was evaluated with QUADAS-2.

RESULTS

Twenty studies evaluating 790 patients for BME in the appendicular skeleton were included in analysis. The summary sensitivity, specificity, and AUC values for BME in the appendicular skeleton were 86% (95% confidence interval [CI] 82-89%), 93% (95% CI 90-95%), and 0.95, respectively. Quantitative analysis had a higher sensitivity than qualitative analysis on meta-regression (p = 0.01), but no difference in specificity (p = 0.28). No other covariates contributed to variability in accuracy (etiology (trauma vs non-trauma); location (upper vs lower extremity); and RoB). Studies demonstrated generally low or unclear RoB and applicability. Eight studies included index tests with high RoB when quantitative assessments used a retrospective cut-off value.

CONCLUSIONS

DECT demonstrates a higher specificity than sensitivity and AUC > 0.9. In scenarios where MRI availability is limited or contraindicated, DECT could be an alternative to MRI for detecting BME in the appendicular skeleton. However, limitations in sources of variability and RoB warrant continued study.

KEY POINTS

• Twenty studies evaluating 790 patients for bone marrow edema in the appendicular skeleton with dual-energy CT were included in analysis. • The summary sensitivity, specificity, and AUC values for detecting bone marrow in the appendicular skeleton were 86% (95% confidence interval [CI] 82-89%), 93% (95% CI 90-95%), and 0.95, respectively. • In scenarios where MRI availability is limited or is contraindicated, DECT could be an alternative to MRI for detecting bone marrow edema in the appendicular skeleton.

Differentiation of usual vertebral compression fractures using CT histogram analysis as quantitative biomarkers: A proof-of-principle study

PURPOSE

To investigate the utility of CT histogram analysis (CTHA) for discrimination of traumatic, osteoporotic and malignant fractures in patients with vertebral compression fractures (VCFs). To evaluate the feasibility and accuracy of CTHA in differentiating non-malignant (traumatic and osteoporotic) from malignant VCFs.

MATERIALS AND METHODS

Totally, 235 patients with VCFs were enrolled in the current experimental study. There were 132 patients with traumatic VCFs, 51 with osteoporotic VCFs and 52 with malignant VCFs, with MRI and histology as the standard references. All the patients underwent unenhanced CT scans. Nineteen histogram-based parameters were derived using Omni-Kinetics software (Omni-Kinetics, GE Healthcare). The reproducibility of those parameters was evaluated using two independent delineations conducted by two observers. These histogram parameters were compared among the three different VCFs using Kruskal-Wallis H test. Traumatic VCFs and osteoporotic VCFs were combined as non-malignant VCFs and compared with malignant VCFs using Mann-Whitney U test Multivariable logistic regression analysis was performed on the significantly different features and built a diagnosis model. Receiver operating characteristic (ROC) curve was carried out to observe the difference of diagnostic performance between the single positive parameter and the combination of parameters.

RESULTS

All the 19 parameters presented excellent reproducibility, with intraclass correlation coefficient values from 0.789 to 0.997. At quantitative evaluation, the best predictive histogram parameters in discrimination of the three different types of VCFs were relative min intensity (p = 0.022), relative entropy (p = 0.043), and relative frequency size (p < 0.001). Relative frequency size (p < 0.001) and relative quantile5 (p = 0.012) resulted in statistically significant difference between non-malignant and malignant VCFs. The area under ROC curve indicated that relative frequency size combined with relative quantile5 (0.754; 95 % confidence intervals: 0.661∼0.829; p < 0.001) was of best performance in differentiating malignant from non-malignant VCFs.

CONCLUSIONS

Our results are encouraging and suggest that histogram parameters derived from unenhanced CT could be reliable quantitative biomarkers for diff ;erential diagnosis of usual VCFs.

Dual-Energy CT of Material Decomposition Analysis for Detection with Bone Marrow Edema in Patients with Vertebral Compression Fractures

RATIONALE AND OBJECTIVES

This study investigated detecting bone marrow edema (BME) in patients with vertebral compression fractures. We compared dual-energy material density analysis images to magnetic resonance imaging (MRI), which is considered the gold standard.

MATERIALS AND METHODS

In this retrospective study, 260 vertebral bodies from 30 patients (11 males, 19 females, mean age of 81) were assessed by MRI and dual-energy material density analysis. Diagnostic accuracy was assessed using the receiver operating characteristic (ROC) curve. Fifty-two of the 260 vertebral bodies were considered to have BME based on the dual-energy material density analysis images; 50 were deemed to have BME by MRI.

RESULTS

ROC analysis of the dual-energy material density analysis values revealed an area under the ROC curve of 0.95 for radiologist 1, 0.97 for radiologist 2, and 0.96 for radiologist 3. A mean cutoff value of 1032.6 mg/cm³ provided an overall sensitivity of 93.0% (95% confidence intervals [CI]: 86.0%-99.9%), specificity of 98.0% (95% CI: 95.5%-99.0%), accuracy of 97.0% (95% CI: 95.2%-99.0%), positive predictive value of 95.0% (95% CI: 81.0%-97.5%), and negative predictive value of 98.0% (95% CI: 93.0%-99.9%).

CONCLUSION

BME in patients with vertebral compression fractures can be detected using dual-energy material density analysis images.

Diagnostic performance of dual-energy CT for the detection of bone marrow oedema: a systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis was to assess the sensitivity and specificity of dual-energy CT (DECT) for the detection of bone marrow oedema (BME).

METHODS

An electronic search of the PubMed and EMBASE databases was conducted. Bivariate modelling and hierarchical summary receiver-operating characteristic modelling were performed to evaluate the overall diagnostic performance of DECT for BME. Subgroup analysis was performed according to the assessment type (qualitative vs. quantitative) and anatomical location (spine vs. appendicular skeleton). Meta-regression analyses were performed according to the subject, study, and DECT characteristics.

RESULTS

Twelve eligible studies (1901 lesions, 450 patients) were included. DECT exhibited a pooled sensitivity of 0.85 [95% confidence interval (CI): 0.78-0.90] and a pooled specificity of 0.97 (95% CI: 0.92-0.98) for BME detection. In addition, the diagnostic performance of qualitative assessment (sensitivity, 0.85; specificity, 0.97) was higher than that of quantitative assessment (sensitivity, 0.84; specificity, 0.88) of DECT findings. The diagnostic performance of DECT for the spine (sensitivity, 0.84; specificity, 0.98) and appendicular skeleton (sensitivity, 0.84; specificity, 0.93) were excellent. According to meta-regression analysis, the use of a tin filter, ≥ 2 image planes, and a slice thickness < 1 mm tended to exhibit higher sensitivity and hyperacute stage BME (< 24 h) tended to exhibit lower sensitivity.

CONCLUSIONS

These findings indicate that DECT has excellent sensitivity and specificity for BME detection. Qualitative assessment of DECT findings obtained using a tin filter, ≥ 2 image planes, and a 0.5-1-mm slice thickness in the acute stage BME (≥24 h) is recommended for more sensitive diagnosis.

KEY POINTS

• Overall, DECT is useful for the detection of BME (sensitivity, 85%; specificity-97%). • Qualitative assessment (sensitivity-85%; specificity-97%) is more accurate than quantitative assessment (sensitivity-84%; specificity-88%). • DECT showed excellent diagnostic performance for both the spine/appendicular skeleton (sensitivity-84%/84%; specificity-98%/93%).