The value of magnetic resonance imaging and computed tomography in the study of spinal disorders

Assessment of Hidden Blood Loss in Spinal Metastasis Surgery: A Comprehensive Approach with MRI-Based Radiomics Models

BACKGROUND

Patients undergoing surgery for spinal metastasis are predisposed to hidden blood loss (HBL), which is associated with poor surgical outcomes but unpredictable.

PURPOSE

To evaluate the role of MRI-based radiomics models for assess the risk of HBL in patients undergoing spinal metastasis surgery.

STUDY TYPE

Retrospective.

SUBJECTS

202 patients (42.6% female) operated on for spinal metastasis with a mean age of 58 ± 11 years were divided into a training (n = 162) and a validation cohort (n = 40).

FIELD STRENGTH/SEQUENCE

1.5T or 3.0T scanners. Sagittal T1-weighted and fat-suppressed T2-weighted imaging sequences.

ASSESSMENT

HBL was calculated using the Gross formula. Patients were classified as low and high HBL group, with 1000 mL as the threshold. Radiomics models were constructed with radiomics features. The radiomics score (Radscore) was obtained from the optimal radiomics model. Clinical variables were accessed using univariate and multivariate logistic regression analyses. Independent risk variables were used to build a clinical model. Clinical variables combined with Radscore were used to establish a combined model.

STATISTICAL TESTS

Predictive performance was evaluated using area under the curve (AUC), accuracy, sensitivity, specificity, and F1 score. Calibration curves and decision curves analyses were produced to evaluate the accuracy and clinical utility.

RESULTS

Among the radiomics models, the fusion (T1WI + FS-T2WI) model demonstrated the highest predictive efficacy (AUC: 0.744, 95% confidence interval [CI]: 0.576-0.914). The Radscore model (AUC: 0.809, 95% CI: 0.664-0.954) performs slightly better than the clinical model (AUC: 0.721, 95% CI: 0.524-0.918; P = 0.418) and the combined model (AUC: 0.752, 95% CI: 0.593-0.911; P = 0.178).

DATA CONCLUSION

A radiomics model may serve as a promising assessment tool for the risk of HBL in patients undergoing spinal metastasis surgery, and guide perioperative planning to improve surgical outcomes.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

International Consensus Statement on the Radiological Evaluation of Dysraphic Malformations of the Spine and Spinal Cord

Dysraphic malformations of the spine and spinal cord (DMSSC) represent a spectrum of common congenital anomalies typically (though not exclusively) affecting the lower spinal segments. These may be responsible for varying degrees of neurologic, orthopedic, and urologic morbidity. With advances in neuroimaging, it is now possible to better diagnose and evaluate these disorders both prenatally and postnatally. Neuroimaging, performed at the right time and with technique optimization, is integral in guiding clinical management. However, the terminology used to describe these lesions has become increasingly confusing, and there is a lack of consensus regarding the essential radiologic features and their clinical weighting. This variability in radiologic practice risks unstructured decision making and increases the likelihood of suboptimal, less informed clinical management. In this manuscript, the first of a series of consensus statements, we outline a standardized international consensus statement for the radiologic evaluation of children with suspected DMSSC derived from a critical review of the literature, and the collective clinical experience of a multinational group of experts. We provide recommendations for plain radiography, sonography, CT, and MR imaging in the evaluation of DMSSC with an emphasis on technique of imaging and imaging protocols.

The Small Pixel Effect in Ultra-High-Resolution Photon-Counting CT of the Lumbar Spine

OBJECTIVES

Image acquisition in ultra-high-resolution (UHR) scan mode does not impose a dose penalty in photon-counting CT (PCCT). This study aims to investigate the dose saving potential of using UHR instead of standard-resolution PCCT for lumbar spine imaging.

MATERIALS AND METHODS

Eight cadaveric specimens were examined with 7 dose levels (5-35 mGy) each in UHR (120 × 0.2 mm) and standard-resolution acquisition mode (144 × 0.4 mm) on a first-generation PCCT scanner. The UHR images were reconstructed with 3 dedicated bone kernels (Br68 [spatial frequency at 10% of the modulation transfer function 14.5 line pairs/cm], Br76 [21.0], and Br84 [27.9]), standard-resolution images with Br68 and Br76. Using automatic segmentation, contrast-to-noise ratios (CNRs) were established for lumbar vertebrae and psoas muscle tissue. In addition, image quality was assessed subjectively by 19 independent readers (15 radiologists, 4 surgeons) using a browser-based forced choice comparison tool totaling 16,974 performed pairwise tests. Pearson's correlation coefficient ( r ) was used to analyze the relationship between CNR and subjective image quality rankings, and Kendall W was calculated to assess interrater agreement.

RESULTS

Irrespective of radiation exposure level, CNR was higher in UHR datasets than in standard-resolution images postprocessed with the same reconstruction parameters. The use of sharper convolution kernels entailed lower CNR but higher subjective image quality depending on radiation dose. Subjective assessment revealed high interrater agreement ( W = 0.86; P < 0.001) with UHR images being preferred by readers in the majority of comparisons on each dose level. Substantial correlation was ascertained between CNR and the subjective image quality ranking (all r 's ≥ 0.95; P < 0.001).

CONCLUSIONS

In PCCT of the lumbar spine, UHR mode's smaller pixel size facilitates a considerable CNR increase over standard-resolution imaging, which can either be used for dose reduction or higher spatial resolution depending on the selected convolution kernel.

Multidisciplinary and Coordinated Management of Osteoporotic Vertebral Compression Fractures: Current State of the Art

Osteoporotic vertebral compression fractures (OVCFs) present a significant health concern, affecting a substantial portion of the older adult population worldwide. This narrative review explores the prevalence, diagnostic challenges and management strategies for OVCFs. Despite the increasing incidence and impact on morbidity and mortality, existing clinical guidelines lack consistency and clear diagnostic and therapeutic recommendations. The review addresses key questions faced by physicians dealing with older adult patients experiencing acute back pain, offering insights into triage, radiological assessments and classification systems. We propose a comprehensive algorithm for clearing OVCF, considering clinical presentation, radiological findings and morphological aspects. Emphasis is placed on the importance of medically treating osteoporosis alongside OVCF management. The review encompasses relevant literature from 1993 to 2023, provides a detailed discussion on triage issues and incorporates a clinically oriented classification system developed by the German Society for Orthopaedics and Trauma. The Material and Methods section outlines the extensive literature search carried out in PUBMED, encompassing clinical and experimental studies, systematic reviews and meta-analyses. The articles retained focused mainly on answering critical questions regarding radiological assessments, imaging modalities and the presence of a specific classification system for OVCFs. The review emphasises that the evaluation and management of OVCFs necessitates a multidisciplinary approach involving spine specialists and bone disease experts. It also addresses the role of conservative versus surgical treatments, with a focus on percutaneous vertebral augmentation. The conclusion summarises the algorithm derived for use in emergency departments and general practice, aiming to streamline OVCF management, reduce unnecessary examinations and ensure optimal patient care. The algorithm recommends primary diagnosis using computed tomography, with magnetic resonance imaging reserved for specific cases. The review advocates a holistic approach, integrating medical and surgical interventions to address the complex challenges posed by OVCFs in ageing populations.

Value of chemical shift imaging in the evaluation of neural foramen stenosis

Background

Chemical shift Magnetic Resonance Imaging (MRI) is often routinely acquired to assess a spectrum of spinal lesions due to its ability versatility to obtain rapid sequences at the expense of spatial resolution images. It is one of the quickest sequences to acquire at the expense of spatial resolution.

Objective

In this study we assess the diagnostic efficacy of Chemical shift Magnetic Resonance Imaging (MRI) in the evaluation of Neural Foraminal stenosis.

Materials and methods

Conventional T2, T1 and STIR sagittal and axial images as well as 'in' and 'out' phase chemical shift sagittal MRI sequences of 25 consecutive patients presenting with back pain and radiculopathy were reviewed. The degree of neural stenosis in the lumbar spine foramina on both sides was graded using the Lee classification on T2 and 'in' and 'out' phase MRI sequences by two independent MSK radiologists. Statistical analysis was performed using paired T-Test and Cohen's weighted kappa test was applied as a measure of agreement between the two observed raters.

Results

A total of 250 lumbar neural foramina were assessed. There was substantial agreement (Cohen's weighted kappa) for both raters between 'in' and 'out' phase chemical shift sagittal MRI sequences (rater 1 = 0.699, rater 2 = 0.718), as well as good agreement between raters for both 'in' and 'out' phase chemical shift sagittal MRI sequences (in phase = 0.656, 'out' phase = 0.576). However, when compared to the gold standard rating on a T2 based sequence, ratings on in' and 'out' phase MRI sequences overestimated the degree of stenosis. When comparing 'in' and 'out' ratings to the T2 ratings, agreement was poor with kappa ranging from 0.132 to 0.202.

Conclusion

Though both 'in' and 'out' phase chemical shift sagittal MRI sequences can be used to analyse neural foraminal stenosis, given its propensity to over-estimate the degree of stenosis in comparison to the T2 based images, assessment of the condition on these complementary limited sequences technique should be avoided/should be undertaken with caution.

The Educational Impact of Radiology in Anatomy Teaching: A Field Study Using Cross-Sectional Imaging and 3D Printing for the Study of the Spine

INTRODUCTION

Cross-sectional imaging and 3D printing represent state-of-the-art approaches to improve anatomy teaching compared to traditional learning, but their use in medical schools remains limited. This study explores the utility of these educational tools for teaching normal and pathological spinal anatomy, aiming to improve undergraduate medical education.

MATERIALS AND METHODS

A field study was conducted on a cohort of undergraduate medical students who were exposed to anatomy lessons of the spine considering three learning paradigms: traditional learning, cross-sectional imaging examinations, and 3D printed models. 20 students (intervention group) received the three approaches, and other 20 students (control group) received the conventional (traditional) approach. The students were examined through a multiple-choice test and their results were compared to those of a control group exposed to traditional learning matched by age, sex and anatomy grades. In addition, students in the experimental group were assessed for their satisfaction with each learning method by means of an ad hoc questionnaire.

RESULTS

Students exposed to cross-sectional imaging and 3D printing demonstrated better knowledge outcomes compared to the control group. They showed high satisfaction rates and reported that these technologies enhanced spatial understanding and facilitated visualization of specific pathologies. However, limitations such as the representativeness of non-bone conditions in 3D printed models and the need for further knowledge on imaging fundamentals were highlighted.

CONCLUSION

Cross-sectional imaging and 3D printing offer valuable tools for enhancing the teaching of spinal anatomy in undergraduate medical education. Radiologists are well positioned to lead the integration of these technologies, and further research should explore their potential in teaching anatomy across different anatomical regions.

Pneumorrhachis Secondary to a Locally Advanced Rectal Cancer with Pre-Sacral Abscess-Case Report and Review

The occurrence of pneumorrhachis (PR), defined as the presence of air within the spinal canal, presents a complex clinical picture with diverse etiological factors. We report an exceedingly rare case of PR arising from locally advanced rectal cancer accompanied by a pre-sacral abscess. This report aims to enhance awareness and understanding of rare causes of PR within the medical community, particularly among surgeons engaged in emergency procedures. The patient survived the acute phase of the disease through multiple surgical interventions and admission to the intensive care unit, but succumbed to cardiovascular complications three weeks later. We also offer a brief review of the literature concerning PR originating from the colorectal lumen.

Imaging of low-energy vertebral fractures

Low-energy vertebral fractures pose a diagnostic challenge for the radiologist due to their often-inadvertent nature and often subtle imaging semiology. However, the diagnosis of this type of fractures can be decisive, not only because it allows targeted treatment to prevent complications, but also because of the possibility of diagnosing systemic pathologies such as osteoporosis or metastatic disease. Pharmacological treatment in the first case has been shown to prevent the development of other fractures and complications, while percutaneous treatments and various oncological therapies can be an alternative in the second case. Therefore, it is necessary to know the epidemiology and typical imaging findings of this type of fractures. The objective of this work is to review the imaging diagnosis of low-energy fractures, with special emphasis on the characteristics that should be outlined in the radiological report to guide a specific diagnosis that favours and optimizes the treatment of patients suffering of low energy fractures.