Identification of prevalent vertebral fractures using CT lateral scout views: a comparison of semi-automated quantitative vertebral morphometry and radiologist semi-quantitative grading

Opportunistic Screening Techniques for Analysis of CT Scans

PURPOSE OF REVIEW

Opportunistic screening is a combination of techniques to identify subjects of high risk for osteoporotic fracture using routine clinical CT scans prescribed for diagnoses unrelated to osteoporosis. The two main components are automated detection of vertebral fractures and measurement of bone mineral density (BMD) in CT scans, in which a phantom for calibration of CT to BMD values is not used. This review describes the particular challenges of opportunistic screening and provides an overview and comparison of current techniques used for opportunistic screening. The review further outlines the performance of opportunistic screening.

RECENT FINDINGS

A wide range of technologies for the automatic detection of vertebral fractures have been developed and successfully validated. Most of them are based on artificial intelligence algorithms. The automated differentiation of osteoporotic from traumatic fractures and vertebral deformities unrelated to osteoporosis, the grading of vertebral fracture severity, and the detection of mild vertebral fractures is still problematic. The accuracy of automated fracture detection compared to classical radiological semi-quantitative Genant scoring is about 80%. Accuracy errors of alternative BMD calibration methods compared to simultaneous phantom-based calibration used in standard quantitative CT (QCT) range from below 5% to about 10%. The impact of contrast agents, frequently administered in clinical CT on the determination of BMD and on fracture risk determination is still controversial. Opportunistic screening, the identification of vertebral fracture and the measurement of BMD using clinical routine CT scans, is feasible but corresponding techniques still need to be integrated into the clinical workflow and further validated with respect to the prediction of fracture risk.

UK clinical guideline for the prevention and treatment of osteoporosis

The National Osteoporosis Guideline Group (NOGG) has revised the UK guideline for the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women, and men age 50 years and older. Accredited by NICE, this guideline is relevant for all healthcare professionals involved in osteoporosis management.

INTRODUCTION

The UK National Osteoporosis Guideline Group (NOGG) first produced a guideline on the prevention and treatment of osteoporosis in 2008, with updates in 2013 and 2017. This paper presents a major update of the guideline, the scope of which is to review the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women, and men age 50 years and older.

METHODS

Where available, systematic reviews, meta-analyses and randomised controlled trials were used to provide the evidence base. Conclusions and recommendations were systematically graded according to the strength of the available evidence.

RESULTS

Review of the evidence and recommendations are provided for the diagnosis of osteoporosis, fracture-risk assessment and intervention thresholds, management of vertebral fractures, non-pharmacological and pharmacological treatments, including duration and monitoring of anti-resorptive therapy, glucocorticoid-induced osteoporosis, and models of care for fracture prevention. Recommendations are made for training; service leads and commissioners of healthcare; and for review criteria for audit and quality improvement.

CONCLUSION

The guideline, which has received accreditation from the National Institute of Health and Care Excellence (NICE), provides a comprehensive overview of the assessment and management of osteoporosis for all healthcare professionals involved in its management. This position paper has been endorsed by the International Osteoporosis Foundation and by the European Society for the Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases.

A deep-learning model for identifying fresh vertebral compression fractures on digital radiography

OBJECTIVES

To develop a deep-learning (DL) model for identifying fresh VCFs from digital radiography (DR), with magnetic resonance imaging (MRI) as the reference standard.

METHODS

Patients with lumbar VCFs were retrospectively enrolled from January 2011 to May 2020. All patients underwent DR and MRI scanning. VCFs were categorized as fresh or old according to MRI results, and the VCF grade and type were assessed. The raw DR data were sent to InferScholar Center for annotation. A DL-based prediction model was built, and its diagnostic performance was evaluated. The DeLong test was applied to assess differences in ROC curves between different models.

RESULTS

A total of 1877 VCFs in 1099 patients were included in our study and randomly divided into development (n = 824 patients) and test (n = 275 patients) datasets. The ensemble model identified fresh and old VCFs, reaching an AUC of 0.80 (95% confidence interval [CI], 0.77-0.83), an accuracy of 74% (95% CI, 72-77%), a sensitivity of 80% (95% CI, 77-83%), and a specificity of 68% (95% CI, 63-72%). Lateral (AUC, 0.83) views exhibited better performance than anteroposterior views (AUC, 0.77), and the best performance among respective subgroupings was obtained for grade 3 (AUC, 0.89) and crush-type (AUC, 0.87) subgroups.

CONCLUSION

The proposed DL model achieved adequate performance in identifying fresh VCFs from DR.

KEY POINTS

• The ensemble deep-learning model identified fresh VCFs from DR, reaching an AUC of 0.80, an accuracy of 74%, a sensitivity of 80%, and a specificity of 68% with the reference standard of MRI. • The lateral views (AUC, 0.83) exhibited better performance than anteroposterior views (AUC, 0.77). • The grade 3 (AUC, 0.89) and crush-type (AUC, 0.87) subgroups showed the best performance among their respective subgroupings.

Opportunistic diagnosis of osteoporosis, fragile bone strength and vertebral fractures from routine CT scans; a review of approved technology systems and pathways to implementation

Osteoporosis causes bones to become weak, porous and fracture more easily. While a vertebral fracture is the archetypal fracture of osteoporosis, it is also the most difficult to diagnose clinically. Patients often suffer further spine or other fractures, deformity, height loss and pain before diagnosis. There were an estimated 520,000 fragility fractures in the United Kingdom (UK) in 2017 (costing £4.5 billion), a figure set to increase 30% by 2030. One way to improve both vertebral fracture identification and the diagnosis of osteoporosis is to assess a patient's spine or hips during routine computed tomography (CT) scans. Patients attend routine CT for diagnosis and monitoring of various medical conditions, but the skeleton can be overlooked as radiologists concentrate on the primary reason for scanning. More than half a million CT scans done each year in the National Health Service (NHS) could potentially be screened for osteoporosis (increasing 5% annually). If CT-based screening became embedded in practice, then the technique could have a positive clinical impact in the identification of fragility fracture and/or low bone density. Several companies have developed software methods to diagnose osteoporosis/fragile bone strength and/or identify vertebral fractures in CT datasets, using various methods that include image processing, computational modelling, artificial intelligence and biomechanical engineering concepts. Technology to evaluate Hounsfield units is used to calculate bone density, but not necessarily bone strength. In this rapid evidence review, we summarise the current literature underpinning approved technologies for opportunistic screening of routine CT images to identify fractures, bone density or strength information. We highlight how other new software technologies have become embedded in NHS clinical practice (having overcome barriers to implementation) and highlight how the novel osteoporosis technologies could follow suit. We define the key unanswered questions where further research is needed to enable the adoption of these technologies for maximal patient benefit.

Osteoporotic Vertebral Fractures are Common in Hip Fracture Patients and are Under-recognized

INTRODUCTION

The vertebrae are the most common site for osteoporotic fracture. While they can result in disability and increased mortality, only one-third present clinically. People with multiple fractures are at greater risk of future fractures. Most hip fracture patients are neither diagnosed nor treated for their underlying osteoporosis. Computed tomography (CT) studies are often performed on hospitalised patients, can be used to diagnose osteoporosis and are gaining popularity for opportunistic osteoporosis screening by measuring BMD and other bone strength indices. The aim of this study was to assess the prevalence of vertebral fractures on CT pulmonary angiograms (CTPA) in a cohort of hip fracture patients and whether this increased their diagnosis and treatment rates.

METHODS

We retrospectively identified all hip fractures admitted to our institution between 2010 and 2017 to identify those who underwent CTPA scans. An independent, blinded consultant musculoskeletal radiologist reviewed the images for vertebral fractures and quantified severity using Genant criteria. Results were compared to the original radiology report, discharge diagnoses and treatment rates for osteoporosis.

RESULTS

Eleven percent (225/2122) of patients had CTPA images available. Seventy percent (158) were female with a mean age of 78 years (SD: 11). The median length of stay for all patients was 16 days (1-301). Forty percent (90) of patients had at least one vertebral fracture present and 20% (46) had more than one fracture. Only one in 5 radiology reports noted the fractures. 24% of subjects had osteoporosis treatment recorded at hospital discharge and there was no difference between those with vertebral fractures to those without.

CONCLUSION

Many hip fracture patients have undiagnosed spine fractures. A screening strategy which evaluates CT scans for fractures has potential to increase diagnosis and treatment rates of osteoporosis. However, more work is needed to increase awareness.

Morphometric vertebral fractures in patients with castration-resistant prostate cancer undergoing treatment with radium-223: a longitudinal study in the real-life clinical practice

PURPOSE

Radium-223 was associated with high incidence of non-vertebral fractures in patients with castration-resistant prostate cancer (CRPC). However, it is still unclear whether radium-223 may induce skeletal fragility regardless of other therapies for CRPC. We aimed at evaluating the prevalence, incidence, and determinants of vertebral fractures (VFs), i.e., the most frequent complication of skeletal fragility, in CRCP patients undergoing radium-223 therapy in the real-life clinical practice.

METHODS

We retrospectively reviewed 49 CRPC patients with symptomatic bone metastases treated with radium-223. Patients received median number of four radium-223 doses (range: 2-6) and were followed-up for a median period of 11 months (range: 6-44). VFs were assessed by a quantitative morphometry using lateral images of spine 11C-Choline PET/CT, excluding from the analysis the vertebral bodies affected by bone metastases.

RESULTS

Before radium-223 administration, 24 patients (49%) had VFs significantly associated with duration of androgen deprivation therapy (ADT; odds ratio 1.29) and previous abiraterone therapy (odds ratio 3.80). During radium-223 therapy, incident VFs occurred in 25% of patients, in relationship with prevalent VFs (hazard ratio 6.89) and change in serum total alkaline phosphatase values (hazard ratio 0.97), whereas the correlations with ADT and abiraterone therapy were lost. Noteworthy, the risk of VFs did not correlate with the therapeutic end points of radium-223.

CONCLUSIONS

This study provides a first evidence that in real-life clinical practice, radium-223 therapy may induce skeletal fragility with high risk of VFs, likely by inhibition of bone formation and independently of ADT and abiraterone therapy.

Heterogeneity and Spatial Distribution of Intravertebral Trabecular Bone Mineral Density in the Lumbar Spine Is Associated With Prevalent Vertebral Fracture

The spatial heterogeneity in trabecular bone density within the vertebral centrum is associated with vertebral strength and could explain why volumetric bone mineral density (vBMD) exhibits low sensitivity in identifying fracture risk. This study evaluated whether the heterogeneity and spatial distribution of trabecular vBMD are associated with prevalent vertebral fracture. We examined the volumetric quantitative computed tomography (QCT) scans of the L3 vertebra in 148 participants in the Framingham Heart Study Multidetector CT study. Of these individuals, 37 were identified as cases of prevalent fracture, and 111 were controls, matched on sex and age with three controls per case. vBMD was calculated within 5-mm contiguous cubic regions of the centrum. Two measures of heterogeneity were calculated: (i) interquartile range (IQR); and (ii) quartile coefficient of variation (QCV). Ratios in the spatial distributions of the trabecular vBMD were also calculated: anterior/posterior, central/outer, superior/mid-transverse, and inferior/mid-transverse. Heterogeneity and spatial distributions were compared between cases and controls using Wilcoxon rank sum tests and t tests and tested for association with prevalent fractures with conditional logistic regressions independent of integral vBMD. Prevalent fracture cases had lower mean ± SD integral vBMD (134 ± 38 versus165 ± 42 mg/cm3 , p < .001), higher QCV (0.22 ± 0.13 versus 0.17 ± 0.09, p = .003), and lower anterior/posterior rBMD (0.65 ± 0.13 versus 0.78 ± 0.16, p < .001) than controls. QCV was positively associated with increased odds of prevalent fracture (OR 1.61; 95% CI, 1.04 to 2.49; p = .034), but this association was not independent of integral vBMD (p = .598). Increased anterior/posterior trabecular vBMD ratio was associated with decreased odds of prevalent fracture independent of integral vBMD (OR 0.38; 95% CI, 0.20 to 0.71; p = .003). In conclusion, increased trabecular vBMD in the anterior versus posterior centrum, but not trabecular vBMD heterogeneity, was associated with decreased risk of prevalent fracture independent of integral vBMD. Regional measurements of trabecular vBMD could aid in determining the risk and underlying mechanisms of vertebral fracture. © 2019 American Society for Bone and Mineral Research.

The association of calcium intake with osteoporotic vertebral fractures in a large Chinese cohort

The effect of calcium on prevention of osteoporosis and related fracture which are aging issues is unclear. The aim of this study is to explore the association of calcium intake with vertebral fracture. This study enrolled 3,457 participants from China Action on Spine and Hip Status (CASH) study from 2013 and 2017. Dietary calcium intake was collected using validated food frequency questionnaires (FFQ). Vertebral fracture of CT images was defined as the primary outcome. The mean calcium intake of men and women were 522.75mg/day and 507.21mg/day, respectively. 6% reduction in the odds of fracture risk was observed per 100 unit increase of calcium intake from food among females (OR, 0.94; 95% CI, 0.89-0.99), but results among males were not significant. We divided calcium intake into quintiles when modelling its associations with fracture risk, negative associations of fracture risk with calcium intake were found among females. In a population with low usual calcium intake, higher dietary calcium intake was associated with fewer vertebral fracture in women and that no such association was seen in men.

Translation of Quantitative Imaging Biomarkers into Clinical Chest CT

Quantitative imaging has been proposed as the next frontier in radiology as part of an effort to improve patient care through precision medicine. In 2007, the Radiological Society of North America launched the Quantitative Imaging Biomarkers Alliance (QIBA), an initiative aimed at improving the value and practicality of quantitative imaging biomarkers by reducing variability across devices, sites, patients, and time. Chest CT occupies a strategic position in this initiative because it is one of the most frequently used imaging modalities, anatomically encompassing the leading causes of mortality worldwide. To date, QIBA has worked on profiles focused on the accurate, reproducible, and meaningful use of volumetric measurements of lung lesions in chest CT. However, other quantitative methods are on the verge of translation from research grounds into clinical practice, including (a) assessment of parenchymal and airway changes in patients with chronic obstructive pulmonary disease, (b) analysis of perfusion with dual-energy CT biomarkers, and (c) opportunistic screening for coronary atherosclerosis and low bone mass by using chest CT examinations performed for other indications. The rationale for and the key facts related to the application of these quantitative imaging biomarkers in cardiothoracic chest CT are presented. ^©RSNA, 2019 See discussion on this article by Buckler (pp 977-980).

Vertebral Fracture Identification as Part of a Comprehensive Risk Assessment in Patients with Osteoporosis

PURPOSE OF REVIEW

To review current evidence regarding the vertebral fracture prevalence, the accuracy of vertebral fracture identification on current imaging technologies, and the potential impact of vertebral fracture identification on fracture risk.

RECENT FINDINGS

Important new studies have clarified the features of prevalent vertebral fracture that most strongly predict incident fractures. Age- and sex-stratified estimates of vertebral fracture prevalence on densitometric lateral spine images in the US population are now available. The accuracy of densitometric vertebral fracture assessment, how computed tomography scans and other spinal images obtained for indications other than vertebral fracture assessment can be leveraged to detect prevalent vertebral fractures, and the potential impact of vertebral fracture assessment on patient and provider fracture risk management behavior have been clarified. Substantial progress has been made regarding screening strategies using lateral spine imaging to detect prevalent vertebral fracture in the older population. Further research regarding implementation of these strategies in clinical practice and their impact on clinical outcomes is needed.

The protocol for the Prospective Urban Rural Epidemiology China Action on Spine and Hip status study

The Prospective Urban Rural Epidemiology (PURE) China Action on Spine and Hip status (CASH) study focused on the prevalence of osteoporosis and spinal fracture in China. The aim of the PURE CASH study is to determine the prevalence of osteoporosis and spinal fracture, and explore the potential relationship between spinal fracture and bone mineral density (BMD). This study is a prospective large-scale population study with a community-based sampling and recruitment strategy. The aim is to determine the prevalence of osteoporosis and vertebral fracture in this population, to evaluate the association between vertebral fractures and BMD values, and to assess the prediction power of BMD for incident fractures. Participants in the PURE CASH study are all from the PURE study in China, recruited from 12 centers in 7 Chinese provinces. The inclusion criteria are that participants should be aged more than 40 years and able to give informed consent. Exclusion criteria are pregnant women, individuals with metal implants in the lumbar spine, use of medications or the existence of any disease or condition known to have a major influence on BMD, and inability to give informed consent. A total of 3,457 participants undergo a quantitative computed tomography (QCT) scan of the upper abdomen. The scanning parameters are as follows: 120 kVp at all centers, mAs between 75 and 200, FOV 40 cm×40 cm. The BMD values of L1 to L3 are measured, and the average BMD calculated. The American College of Radiology QCT criteria for the diagnosis of osteoporosis is applied to determine the presence of osteoporosis. The scout view images of T4-L4 vertebrae are reviewed by two experienced radiologists for semi-quantification of vertebral fractures according to Genant's method.

Osteoporotic Vertebral Fracture Prevalence Varies Widely Between Qualitative and Quantitative Radiological Assessment Methods: The Rotterdam Study

Accurate diagnosis of vertebral osteoporotic fractures is crucial for the identification of individuals at high risk of future fractures. Different methods for radiological assessment of vertebral fractures exist, but a gold standard is lacking. The aim of our study was to estimate statistical measures of agreement and prevalence of osteoporotic vertebral fractures in the population-based Rotterdam Study, across two assessment methods. The quantitative morphometry assisted by SpineAnalyzer® (QM SA) method evaluates vertebral height loss that affects vertebral shape whereas the algorithm-based qualitative (ABQ) method judges endplate integrity and includes guidelines for the differentiation of vertebral fracture and nonfracture deformities. Cross-sectional radiographs were assessed for 7582 participants aged 45 to 95 years. With QM SA, the prevalence was 14.2% (95% CI, 13.4% to 15.0%), compared to 4.0% (95% CI, 3.6% to 4.5%) with ABQ. Inter-method agreement according to kappa (κ) was 0.24. The highest agreement between methods was among females (κ = 0.31), participants age >80 years (κ = 0.40), and at the L₁ level (κ = 0.40). With ABQ, most fractures were found at the thoracolumbar junction (T₁₂ -L₁ ) followed by the T₇ -T₈ level, whereas with QM SA, most deformities were in the mid thoracic (T₇ -T₈ ) and lower thoracic spine (T₁₁ -T₁₂ ), with similar number of fractures in both peaks. Excluding mild QM SA deformities (grade 1 with QM) from the analysis increased, the agreement between the methods from κ = 0.24 to 0.40, whereas reexamining mild deformities based on endplate depression increased agreement from κ = 0.24 to 0.50 (p <0.001). Vertebral fracture prevalence differs significantly between QM SA and ABQ; reexamining QM mild deformities based on endplate depression would increase the agreement between methods. More widespread and consistent application of an optimal method may improve clinical care. © 2017 American Society for Bone and Mineral Research.

Anterior cervical distraction and screw elevating-pulling reduction for traumatic cervical spine fractures and dislocations: A retrospective analysis of 86 cases

Treatment of cervical fracture and dislocation by improving the anterior cervical technique.Anterior cervical approach has been extensively used in treating cervical spine fractures and dislocations. However, when this approach is used in the treatment of locked facet joints, an unsatisfactory intraoperative reduction and prying reduction increases the risk of secondary spinal cord injury. Thus, herein, the cervical anterior approach was improved. With distractor and screw elevation therapy during surgery, the restoration rate is increased, and secondary injury to the spinal cord is avoided.To discuss the feasibility of the surgical method of treating traumatic cervical spine fractures and dislocations and the clinical application.This retrospective study included the duration of patients' hospitalization from January 2005 to June 2015. The potential risks of surgery (including death and other surgical complications) were explained clearly, and written consents were obtained from all patients before surgery.The study was conducted on 86 patients (54 males and 32 females, average age of 40.1 ± 5.6 years) with traumatic cervical spine fractures and dislocations, who underwent one-stage anterior approach treatment. The effective methods were evaluated by postoperative follow-up.The healing of the surgical incision was monitored in 86 patients. The follow-up duration was 18 to 36 (average 26.4 ± 7.1) months. The patients achieved bones grafted fusion and restored spine stability in 3 to 9 (average 6) months after the surgery. Statistically, significant improvement was observed by Frankel score, visual analog scale score, Japanese Orthopedic Association score, and correction rate of the cervical spine dislocation pre- and postoperative (P < .01).The modified anterior cervical approach is simple with a low risk but a good effect in reduction. In addition, it can reduce the risk of iatrogenic secondary spinal cord injury and maintain optimal cervical spine stability as observed during follow-ups. Therefore, it is suitable for clinical promotion and application.

Type 2 diabetes mellitus and bone fragility: Special focus on bone imaging

Fragility fracture rate is increased in type 2 diabetes patients despite of higher bone mineral density than non-diabetes control subjects. Vertebral fractures are usually asymptomatic; therefore, morphometric radiologic evaluation should be considered especially for diabetes patients.

Bone quality may more contribute to the increased risk of osteoporotic fractures in patients with type 2 diabetes than bone mass. Hip geometry, cortical porosity, and trabecular bone score have been studied as bone quality parameters by imaging in type 2 diabetes mellitus.

Precision and Accuracy of Measurements on CT Scout View

OBJECTIVES

The purposes of this study were to (1) investigate the limits of measurements on scout view in three computed tomography axes, x, y and z and (2) develop a model to provide better understanding of measurement accuracy.

METHODS

For the first objective, anteroposterior and lateral scout views of a Catphan phantom 200 mm in diameter and length were acquired with a GE scanner at 21 different table heights. Phantom measurements on scout view were performed by two experienced readers. The comparison of their measures provided estimation of precision. The accuracy was assessed by determining the bias, calculated as the difference between the values measured on scout view and the real phantom size. Second, a model was developed investigating the relationship between the dimensions of the object, its image, and the table height. This relationship was tested on our data.

RESULTS

Scout view measurements were precise, with less than 0.53% difference between readers. In addition, small biases of about 1 mm were detected in the z-axis, whatever the table height. In the other axes, serious biases from -13 to +73 mm were measured. Furthermore, at isocentre, overestimations up to 7 mm were shown. The results also indicated that biases in scout view measurements are because of the geometrical projection related to the object-detector distance.

CONCLUSIONS

Measurements in the table movement axis are precise and accurate, conferring to scout views an added value for preoperative planning in orthopedic surgery.

Prevalent vertebral fractures on chest CT: higher risk for future hip fracture

Subclinical or undiagnosed vertebral fractures on routine chest computed tomography (CT) may be useful for detecting patients at increased risk of future hip fractures who might benefit from preventive interventions. We investigated whether prevalent vertebral fractures on routine chest CT are associated with future hip fractures. From a source population of 5679 patients ≥40 years old undergoing chest CT in one of three Dutch hospitals between 2002 and 2005, patients hospitalized for hip fractures (n = 149) during a median follow-up of 4.4 years were identified. Following a case-cohort design, a random sample of 576 patients was drawn from the source population and added to the cases. In this group, the presence and severity of vertebral fractures was determined using semiquantitative vertebral fracture assessment and multivariate case-cohort appropriate Cox modeling. We found that cases were older (69 versus 63 years) and more often female (48% versus 38%) than the source population. Compared with those with no fracture, patients with any vertebral fracture had triple the risk of future hip fracture (age- and gender-adjusted hazard ratio [HR] = 3.1, 95% confidence interval [CI] 2.1-4.7). This HR rose to 3.8 (CI 2.6-5.6) if mild fractures were discounted. Future fracture risk increased significantly with increasing severity of vertebral fracture status: from mild (HR = 2.4, CI 1.5-3.7) and moderate (HR = 4.8, CI 2.5-9.2) to severe (HR = 6.7, CI 2.9-15.5). The same was true for having higher cumulative fracture grades: 1 to 3 (HR = 2.7, CI 1.8-4.1), 4 to 6 (HR = 4.8, CI 2.2-10.5), or ≥7 (HR = 11.2, CI 3.7-34.6). In conclusion, prevalent vertebral fractures on routine clinical chest CT are associated with future hip fracture risk.

Comprehensive vertebral deformity and vertebral fracture assessment in clinical practice: intra- and inter-reader agreement of a clinical workflow tool

STUDY DESIGN

Study design randomized intra- and inter-reader reproducibility study.

OBJECTIVE

To evaluate reproducibility of quantitative morphometry (QM) and agreement of dichotomous fracture/no-fracture status on lateral spinal radiographs acquired during routine clinical practice using a clinical workflow tool.

SUMMARY OF BACKGROUND DATA

Several recent guidelines have underlined the importance of Genant semi-quantitative scoring and selective QM to confirm and grade suspected vertebral fractures in clinical practice.

METHODS

Thoracic and lumbar spine radiographs were acquired from 98 consecutive subjects (mean age, 60.1 ± 11.7 yr) attending the clinic for osteoporosis evaluation. For each subject, QM and Genant semi-quantitative scoring were performed on all evaluable vertebrae from L4 to T4 using a software workflow tool. A radiologist and an experienced radiographical technician performed 2 repeat reading sessions of the radiographs 12 months apart, blinded to each other's results; for the second read, the cases were anonymized and the order was randomized.

RESULTS

Inter-reader reproducibility results were 3.1% and 3.2% coefficient of variation (%) for heights, 0.030 and 0.031 root mean square standard deviation for height ratios. For intrareader reproducibility, these values were 2.2% and 3.5% coefficient of variation %; 0.023 and 0.034 root mean square standard deviation. Kappa score results for agreement of dichotomous fracture/no-fracture status were 0.67 and 0.72 (inter-rater) and 0.50 and 0.67 (intrarater).

CONCLUSION

The software assessed in this study is a reliable clinical tool that facilitates QM and Genant semi-quantitative scoring of the spine in routine clinical practice.

LEVEL OF EVIDENCE

3.

Reliability and accuracy of scout CT in the detection of vertebral fractures

OBJECTIVE

The aim of the present study was to evaluate the reliability of scout CT (sCT) lateral radiograph, in terms of diagnostic accuracy and intra- and interobserver agreement in the detection of vertebral fractures (VFs).

METHODS

300 CT examinations of the thoracic and/or lumbar spine were collected and independently analysed by 3 musculoskeletal radiologists in 2 different sessions. A semi-quantitative approach was used for VF assessment on sCT, and morphometric analysis was performed when a VF was suspected. Results of multiplanar sagittal CT reconstructions interpreted by the most expert radiologist were considered as gold standard. Arthrosis was also scored. Only vertebral bodies assessable by both sCT and gold standard were considered for the analysis. Area under the receiver operating characteristic curve (AUROC), Cohen's kappa statistic and linear-by-linear association were used for statistical analysis.

RESULTS

1522 vertebrae were considered (130 males and 170 females; ages, 73.0±2.8 years). 73 of 1522 (4.8%) VFs were identified in 34/300 patients (11.3%). In the detection of VFs, the sensitivity and specificity of sCT were 98.7% and 99.7%, respectively. Accuracy (AUROC=0.992±0.008), as well as interobserver agreement (k=0.968±0.008), was excellent. Intra-observer agreement was perfect (k=1.000). Performance of this method was independent of arthrosis, vertebral level and type and grade of VFs.

CONCLUSION

sCT is a simple but very accurate method for the detection of VFs. It should be introduced as a spine evaluation tool for the detection of VFs in examinations that are performed for other diagnostic purposes.

ADVANCES IN KNOWLEDGE

sCT lateral radiograph is an accurate tool for the detection of VFs. This technique may be used with several advantages in clinical practice.

Quantitative vertebral morphometry based on parametric modeling of vertebral bodies in 3D

Quantitative vertebral morphometry (QVM) was performed by parametric modeling of vertebral bodies in three dimensions (3D).

INTRODUCTION

Identification of vertebral fractures in two dimensions is a challenging task due to the projective nature of radiographic images and variability in the vertebral shape. By generating detailed 3D anatomical images, computed tomography (CT) enables accurate measurement of vertebral deformations and fractures.

METHODS

A detailed 3D representation of the vertebral body shape is obtained by automatically aligning a parametric 3D model to vertebral bodies in CT images. The parameters of the 3D model describe clinically meaningful morphometric vertebral body features, and QVM in 3D is performed by comparing the parameters to their statistical values. Thresholds and parameters that best discriminate between normal and fractured vertebral bodies are determined by applying statistical classification analysis.

RESULTS

The proposed QVM in 3D was applied to 454 normal and 228 fractured vertebral bodies, yielding classification sensitivity of 92.5% at 7.5% specificity, with corresponding accuracy of 92.5% and precision of 86.1%. The 3D shape parameters that provided the best separation between normal and fractured vertebral bodies were the vertebral body height and the inclination and concavity of both vertebral endplates.

CONCLUSION

The described QVM in 3D is able to efficiently and objectively discriminate between normal and fractured vertebral bodies and identify morphological cases (wedge, (bi)concavity, or crush) and grades (1, 2, or 3) of vertebral body fractures. It may be therefore valuable for diagnosing and predicting vertebral fractures in patients who are at risk of osteoporosis.

Detection of incidental vertebral fractures in breast imaging: the potential role of MR localisers

OBJECTIVES

Incidental diagnosis of vertebral fractures (VFs) may represent a key point in the assessment of bone health status. Our purpose was to retrospectively evaluate localisation sequences (MR-loc) of breast MRI as a potential tool to detect osteoporotic VFs.

METHODS

MR-loc sagittal images of 856 breast MRIs were reviewed by three expert musculoskeletal radiologists with a semiquantitative approach to detecting VFs. Anamnesis and data of patients were investigated. Official breast MRI and previous imaging reports were checked to understand if VFs or other relevant bone findings were known in patients' clinical history.

RESULTS

A total of 780/856 female patients (91.1 %) undergoing MRI for oncological reasons and 76/856 (8.9 %) with non-oncological aims were recruited into the study (54.7 ± 12.2 years old, 21-89 years); 57/856 MR-loc images (6.7 %) were considered inadequate for diagnostic purposes and were excluded from the analysis. MR-loc detected VFs in 71/799 patients (8.9 %). VFs were neither reported nor previously known in the clinical history of 63/71 patients (88.7 %; P < 0.001). No mention of VFs was found in any breast MR reports. In four patients MR-loc identified vertebral metastases.

CONCLUSIONS

A systematic evaluation of MR-loc may offer additional clinical information to prevent unrecognised VFs. MR-loc may screen for VFs in other imaging settings.

KEY POINTS

Vertebral fractures are usually a hallmark of osteoporosis. Localisation sequences before breast MR examinations can identify vertebral fractures. MR localisers should be inspected for vertebral fractures in other clinical settings.

Identification of prevalent vertebral fractures using CT lateral scout views: a comparison of semi-automated quantitative vertebral morphometry and radiologist semi-quantitative grading

We compared vertebral fracture assessment by semi-automated quantitative vertebral morphometry measurements with the conventional semi-quantitative (SQ) grading using lateral CT scout views. The semi-automated morphometry method showed good to excellent agreement with the visual SQ grading by radiologists for identification of vertebral fractures.

INTRODUCTION

Semi-automated quantitative vertebral morphometry (QM) measurements may enhance management of osteoporosis patients by providing an efficient means to identify vertebral fractures (VFx). We compared identification of prevalent VFx by semi-automated QM to SQ grading.

METHODS

A non-radiologist performed semi-automated QM from CT lateral scout views in 200 subjects (102 men, 98 women, 65.8 ± 8.9 years) selected from the Framingham Heart Study Multidetector CT Study. VFx were classified in the QM approach based on using Genant's criteria for deformities, and compared with conventional SQ grading performed by experienced radiologists as the gold standard. The kappa (k) statistics, percent agreement (% Agree), sensitivity (SE), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV) were computed.

RESULTS

Among 200 subjects, 57 had mild and 41 had moderate or severe VFx by visual SQ grading. Per-person analyses showed excellent agreement between the two methods, with k = 0.780. The % Agree ranged from 86.7% to 91.2%, the SE was 81.3%-96%, and the SP was 86.5%-92%. Among 2,588 vertebrae analyzed, 107 had mild and 49 had moderate or severe VFx by visual SQ grading. Per-vertebra analyses revealed good agreement, with k = 0.580. Agreement between the methods tended to be highest in L1-L4 region. Agreement and validity measures were higher when only moderate and severe fractures were included.

CONCLUSION

The semi-automated quantitative vertebral morphometry measurements from CT lateral scout views provided good to excellent agreement with the standard SQ grading for assessment of prevalent vertebral fractures.