Semiautomatic Assessment of Facet Tropism From Lumbar Spine MRI Using Deep Learning: A Northern Finland Birth Cohort Study

STUDY DESIGN

This is a retrospective, cross-sectional, population-based study that automatically measured the facet joint (FJ) angles from T2-weighted axial magnetic resonance imagings (MRIs) of the lumbar spine using deep learning (DL).

OBJECTIVE

This work aimed to introduce a semiautomatic framework that measures the FJ angles using DL and study facet tropism (FT) in a large Finnish population-based cohort.

SUMMARY OF DATA

T2-weighted axial MRIs of the lumbar spine (L3/4 through L5/S1) for (n=1288) in the NFBC1966 Finnish population-based cohort were used for this study.

MATERIALS AND METHODS

A DL model was developed and trained on 430 participants' MRI images. The authors computed FJ angles from the model's prediction for each level, that is, L3/4 through L5/S1, for the male and female subgroups. Inter-rater and intrarater reliability was analyzed for 60 participants using annotations made by two radiologists and a musculoskeletal researcher. With the developed method, we examined FT in the entire NFBC1966 cohort, adopting the literature definitions of FT thresholds at 7° and 10°. The rater agreement was evaluated both for the annotations and the FJ angles computed based on the annotations. FJ asymmetry ( - was used to evaluate the agreement and correlation between the raters. Bland-Altman analysis was used to assess the agreement and systemic bias in the FJ asymmetry. The authors used the Dice score as the metric to compare the annotations between the raters. The authors evaluated the model predictions on the independent test set and compared them against the ground truth annotations.

RESULTS

This model scored Dice (92.7±0.1) and intersection over union (87.1±0.2) aggregated across all the regions of interest, that is, vertebral body (VB), FJs, and posterior arch (PA). The mean FJ angles measured for the male and female subgroups were in agreement with the literature findings. Intrarater reliability was high, with a Dice score of VB (97.3), FJ (82.5), and PA (90.3). The inter-rater reliability was better between the radiologists with a Dice score of VB (96.4), FJ (75.5), and PA (85.8) than between the radiologists and the musculoskeletal researcher. The prevalence of FT was higher in the male subgroup, with L4/5 found to be the most affected region.

CONCLUSION

The authors developed a DL-based framework that enabled us to study FT in a large cohort. Using the proposed method, the authors present the prevalence of FT in a Finnish population-based cohort.

Cartilaginous endplates: A comprehensive review on a neglected structure in intervertebral disc research

The cartilaginous endplates (CEP) are key components of the intervertebral disc (IVD) necessary for sustaining the nutrition of the disc while distributing mechanical loads and preventing the disc from bulging into the adjacent vertebral body. The size, shape, and composition of the CEP are essential in maintaining its function, and degeneration of the CEP is considered a contributor to early IVD degeneration. In addition, the CEP is implicated in Modic changes, which are often associated with low back pain. This review aims to tackle the current knowledge of the CEP regarding its structure, composition, permeability, and mechanical role in a healthy disc, how they change with degeneration, and how they connect to IVD degeneration and low back pain. Additionally, the authors suggest a standardized naming convention regarding the CEP and bony endplate and suggest avoiding the term vertebral endplate. Currently, there is limited data on the CEP itself as reported data is often a combination of CEP and bony endplate, or the CEP is considered as articular cartilage. However, it is clear the CEP is a unique tissue type that differs from articular cartilage, bony endplate, and other IVD tissues. Thus, future research should investigate the CEP separately to fully understand its role in healthy and degenerated IVDs. Further, most IVD regeneration therapies in development failed to address, or even considered the CEP, despite its key role in nutrition and mechanical stability within the IVD. Thus, the CEP should be considered and potentially targeted for future sustainable treatments.

Are current machine learning applications comparable to radiologist classification of degenerate and herniated discs and Modic change? A systematic review and meta-analysis

INTRODUCTION

Low back pain is the leading contributor to disability burden globally. It is commonly due to degeneration of the lumbar intervertebral discs (LDD). Magnetic resonance imaging (MRI) is the current best tool to visualize and diagnose LDD, but places high time demands on clinical radiologists. Automated reading of spine MRIs could improve speed, accuracy, reliability and cost effectiveness in radiology departments. The aim of this review and meta-analysis was to determine if current machine learning algorithms perform well identifying disc degeneration, herniation, bulge and Modic change compared to radiologists.

METHODS

A PRISMA systematic review protocol was developed and four electronic databases and reference lists were searched. Strict inclusion and exclusion criteria were defined. A PROBAST risk of bias and applicability analysis was performed.

RESULTS

1350 articles were extracted. Duplicates were removed and title and abstract searching identified original research articles that used machine learning (ML) algorithms to identify disc degeneration, herniation, bulge and Modic change from MRIs. 27 studies were included in the review; 25 and 14 studies were included multi-variate and bivariate meta-analysis, respectively. Studies used machine learning algorithms to assess LDD, disc herniation, bulge and Modic change. Models using deep learning, support vector machine, k-nearest neighbors, random forest and naïve Bayes algorithms were included. Meta-analyses found no differences in algorithm or classification performance. When algorithms were tested in replication or external validation studies, they did not perform as well as when assessed in developmental studies. Data augmentation improved algorithm performance when compared to models used with smaller datasets, there were no performance differences between augmented data and large datasets.

DISCUSSION

This review highlights several shortcomings of current approaches, including few validation attempts or use of large sample sizes. To the best of the authors' knowledge, this is the first systematic review to explore this topic. We suggest the utilization of deep learning coupled with semi- or unsupervised learning approaches. Use of all information contained in MRI data will improve accuracy. Clear and complete reporting of study design, statistics and results will improve the reliability and quality of published literature.

Carfentanil on the darknet: Potential scam or alarming public health threat?

BACKGROUND

In an age of global insecurity, highly potent synthetic drugs have become a major public health issue. Their online advertisement and sale are facilitated by surface web, darknet markets and social media fuelling substance abuse and addiction, as well as various types of new criminal activities and their growth in sophistication. This study presents a systematic analysis of the darknet sale of one of the most potent synthetic opioids: Carfentanil. With an equianalgesic potency of 10.000 times a unit of morphine, its toxicity is comparable to traditional nerve agents, and it has been previously used as a chemical weapon, causing human fatalities.

METHODS

Digital trace data was collected retrospectively from all the darknet marketplaces, which have been active in the past five years. Data on vendors offering Carfentanil on Agartha, Empire and Yakuza marketplaces were analysed with regard to items sold and sellers' features as these were the only active markets at the time of search. Searches were carried out in the English language only.

RESULTS

63 Cartfentanil vendors operating on 19 darknet marketplaces were identified. Contacts and payments were facilitated with end-to-end encryption messaging mobile applications and content-expiring messages. Although it is known that Agartha is a scam market, and no operative sellers were found on Yakuza, several sellers promoting Carfentanil sales were active in the Empire marketplace with a number of transaction ranging from 4 to 1223.

CONCLUSION

The availability of highly potent drugs such as Carfentanil on the darknet requires the urgent development of novel scientific methods and tools able to monitor and to predict such new threats, while informing policymaking and protecting the health and the security of citizens.

Immediate effects and associations between interoceptive accuracy and range of motion after a HVLA thrust on the thoracolumbar junction: A randomised controlled trial

BACKGROUND

There is paucity in the literature regarding the role of interoceptive accuracy (IAc) at predicting the effectiveness of osteopathic techniques which increase spinal mobility when directed specifically at the thoracolumbar junction (TLJ).

AIMS

The study aimed to explore whether a high velocity, low amplitude (HVLA) thrust of the TLJ would increase spinal mobility (measured through Range of Motion; ROM) and change IAc. Also, whether baseline IAc correlated with the post-ROM measures and change in ROM.

METHOD

21 asymptomatic participants were allocated into three conditions in a randomised order. These were; (1) a high velocity low amplitude manipulation of the TLJ; (2) sham (basic touch); and (3) a control (laying supine on a plinth). Before and following each intervention, the participants' spinal ROM was measured using an Acumar digital inclinometer. In addition to this an ECG was used to measure their pre and post condition IAc.

RESULTS

There were significant increases in ROM for all condition, however, the HVLA thrust led to a significantly greater increase in ROM (p < 0.001) when compared to the control and sham. Baseline IAc was inversely associated with post-ROM but there was no association with change in ROM. The HVLA thrust did not significantly change IAc scores from pre to post intervention.

CONCLUSIONS

HVLA thrust over the TLJ is a useful intervention for increasing spinal ROM. IAc maybe a useful predictor for intervention effectiveness of this technique and spinal area which could in the future be utilised by osteopaths as part of their diagnostics.

A Mennydörgés Istenének amerikanizálása: hogyan lesz a fiúuralkodóból Asgard jogos királya a Thorban

A tanulmány Terence McSweeney Avengers Assemble! Critical Perspectives on the Marvel Cinematic Universe című könyvének két szövegéből áll, amelyek könnyedén illeszkednek egymáshoz. A Thorral (Kenneth Branagh, 2011) foglalkozó első részben a filmet az amerikai monomítoszokkal és az amerikai politikával, valamint az Egyesült Államokon kívüli amerikai beavatkozással veti össze a szerző, látványos párhuzamokat vonva. A tanulmány második fele a Thor: Sötét világon (Thor: Dark World. Alan Foster, 2014) keresztül a Marvel-filmek problémás nőábrázolását mutatja be, kiemelt helyen kezelve Thor szerelmét, Jane Fostert.

„A világ megváltozott, és egyikünk sem térhet vissza”: a 9/11 utáni szuperhős illuzórikus erkölcsi kétértelműsége az Amerika kapitány: A tél katonájában

A tanulmány, amely Terence McSweeney Avengers Assemble! című 2018-as könyvéből származik, az Amerika kapitány: A tél katonáját elemzi, és azt igyekszik bizonyítani, hogy bár a film a kritikusok szerint az MCU egyik legjobban sikerült darabja, valójában közel sem olyan radikális politikai szempontból, mint elsőre gondolnánk. McSweeney bemutatja, hogy a film drámai hatása elsősorban az Amerika kapitány: Az első bosszúállóban már megismert „nagy generációs” hősi retorika és a morális kompromisszumokra hajlamos modern kor közti feszültségből fakad. A fasiszta Hydra felemelkedéséről, az amerikai kormányba való beférkőzéséről és a Vízió projekt bevezetéséről szóló narratíva egyértelműen az amerikai „terror elleni háborúval” kapcsolatos aggályokra és félelmekre játszik rá. Ennek ellenére azonban politikailag konzervatív alkotásról van szó, amelynek vélt szubverzivitása inkább annak köszönhető, hogy mindenki számára lehetővé teszi, hogy a saját politikai meggyőződését lássa a filmben tükröződni.

Evaluation of a new blood-conserving arterial line system for patients in intensive care units

OBJECTIVE

To evaluate blood samples obtained from a new blood-conserving arterial line system for the presence of hemodilution or heparin contamination.

DESIGN

Prospective, clinical trial.

SETTING

A coronary intensive care unit in a tertiary-care teaching hospital.

PATIENTS

Cardiovascular patients in whom invasive arterial blood pressure monitoring was indicated.

INTERVENTIONS

Paired blood samples were obtained from a conventional arterial line system and a new blood-conserving arterial line system for the measurement of hematocrit and partial thromboplastin time, and compared to evaluate for the presence of either hemodilution or heparin contamination.

MEASUREMENTS AND MAIN RESULTS

A Bland-Altman bias analysis of the variability between the two blood draw methods was performed. The analysis indicated that a) a randomly determined partial thromboplastin time obtained from the blood-conserving arterial line would lie between 3.32 and -5.11 of the partial thromboplastin time taken from the conventional arterial line value with 95% confidence; and b) a randomly determined hematocrit obtained from the blood-conserving arterial line would lie between 1.97 and -1.85 of the hematocrit taken from the conventional arterial line value with 95% confidence.

CONCLUSIONS

We concluded that a) blood samples obtained with the blood-conserving arterial line demonstrate no evidence of hemodilution or heparin contamination; b) the blood-conserving arterial line provides blood samples without the need for an initial volume of blood to be discarded; c) the blood-conserving arterial line provides a means for blood conservation in the intensive care setting.

Cranial nerve palsies in cervical injuries

The occurrence of cranial nerve palsies in cervical injuries is described in eight patients. The clinical features were dramatic and usually presented soon after injury, the most common picture being that of a bulbar palsy, with acute respiratory distress and dysphagia. Neurologic recovery, both from cranial nerve palsies and motor and sensory deficits, was substantial in all instances, suggesting that brain-stem ischaemia due to vertebral artery spasm or compression had been a factor in their causation. Alternatively, differential movement between the base of the skull and the upper part of the cervical spine at the time of injury could have caused an extracranial injury to the lower cranial nerves.

Injuries of the cervical spine

There has been a world-wide increase in serious neck injuries. Better understanding of the altered physiology of spinal man, and the employment of the appropriate supportive measures, has led to a lessening in morbidity. These general measures and the indications for surgery are discussed.

Syringomyelia as a sequel to traumatic paraplegia

Ten cases of post-traumatic paraplegia are described in whom syringomyelia symptoms have supervened. Five patients have been operated upon after investigation. Operative results have been encouraging. A discussion of likely pathogenetic mechanisms is presented.

Paraplegia as a sequela to dorsal disc prolapse

A retrospective study of seven patients referred to a spinal injury unit following surgery for thoracic disc prolapse is presented. Early diagnosis and increased awareness of the condition followed by lateral rhachotomy or anterolateral decompression is essential if the former dismal prognosis is to be improved.

Cervicodorsal injury presenting as sternal fracture

Clinically silent cervicodorsal fracture may occur following upper-thoracic injury in the presence of a characteristic buckling injury to the sternum. Failure to recognise the association may result in gross kyphotic deformity. Three examples are provided, illustrating the role of radiology in the management of this complex traumatic lesion.

Traumatic atlanto-axial fracture disclocation in a child

An 18-month-old child was rendered tetraplegic below C6 in a road traffic accident. There was an associated fracture-dislocation of the atlanto-axial joint. Early management, and the probable role of autonomic dysreflexia in increasing the neurological deficit are considered.

Hidden flexion injury of the cervical spine

This paper describes seven patients who developed late vertebral deformity after flexion injuries of the cervical spine. In four the clinical and radiological features were subtle and because the patients walked into an emergency department the severity of the injury was not initially appreciated. Certain specific clinical and radiological features of flexion injury are described and emphasis is placed on the importance of correct management. A radiological tetrad is described which should alert the surgeon to the possibility of damage to the posterior interspinous complex of the cervical spine and so lead to further radiological investigations. Despite the frequency of flexion injuries the alarming complications described in this paper are rare.