Identifying and documenting osseous trauma from shark attacks by post mortem CT examination and autopsy

A 15-year-old male was attacked by a large white shark while surfing. CT examination revealed an above-knee amputation of the right lower extremity with stripping of soft tissues from the groin distally. 3-dimensional volume rendering did not show any fragments of shark teeth but did reveal linear gouges, areas of shaving of cortical bone and an inverted 'V'-shaped defect at the distal margin of the femoral shaft. At autopsy these injuries were confirmed in addition to areas with fine parallel cross-striations matching the marginal serrations of the teeth of a white shark. Thus, while post mortem CT with 3-dimensional reconstruction at high resolution can show the nature and number of the bony injuries following shark attack, it is complimented by pathological examination which may find fine parallel grooves from teeth serrations. Post mortem 3-dimensional volume rendering may also help to find or exclude fragments of teeth, and silicone casting may provide a permanent record of bone lesions.

Computed Tomographic Findings of Dental Disease and Secondary Diseases of the Head Area in Client-Owned Domestic Rabbits (Oryctolagus cuniculus): 90 Cases

Domestic rabbits have teeth that grow throughout the animal's life and are prone to disease. Clinical signs of dental disease in domestic rabbits are non-specific, and, therefore, a definitive diagnosis usually requires additional methods. This study was carried out on a group of 105 domestic rabbits aged 3 to 9 years. In total, 90 domestic rabbits with dental disease visible on CT images and other secondary diseases of the head area qualified for this study. Malocclusion was found in 57 (63.3%). Retrograde elongation of the tooth apices in the mandible was present in 39 (43.3%), and it was present in the maxilla in 48 (53%). Clinical tooth crowns were overgrown in 39 (43%). Dental abscesses were present in 54 (63%). Secondary to the presence of a dental abscess, osteomyelitis was found in 43 (79% of the animals with a dental abscess). Dental inflammatory resorption was found in 36 (40%). Secondary to dental disease, nasal cavity inflammation was found in 18 (20%). Otitis media was present in six (6.7%). The most common dental disease found in this study's animals was malocclusion secondary to abnormal clinical crown abrasion and abnormal tooth growth. In domestic rabbits, osteomyelitis is a common complication of dental abscesses. Computed tomography is an invaluable diagnostic method in the diagnosis of dental disease and secondary diseases of the head area, such as inflammation of the nasal cavities or otitis media, in pet rabbits.

Parasite escape mechanisms drive morphological diversification in avian lice

Organisms that have repeatedly evolved similar morphologies owing to the same selective pressures provide excellent cases in which to examine specific morphological changes and their relevance to the ecology and evolution of taxa. Hosts of permanent parasites act as an independent evolutionary experiment, as parasites on these hosts are thought to be undergoing similar selective pressures. Parasitic feather lice have repeatedly diversified into convergent ecomorphs in different microhabitats on their avian hosts. We quantified specific morphological characters to determine (i) which traits are associated with each ecomorph, (ii) the quantitative differences between these ecomorphs, and (iii) if there is evidence of displacement among co-occurring lice as might be expected under louse-louse competition on the host. We used nano-computed tomography scan data of 89 specimens, belonging to four repeatedly evolved ecomorphs, to examine their mandibular muscle volume, limb length and three-dimensional head shape data. Here, we find evidence that lice repeatedly evolve similar morphologies as a mechanism to escape host defences, but also diverge into different ecomorphs related to the way they escape these defences. Lice that co-occur with other genera on a host exhibit greater morphological divergence, indicating a potential role of competition in evolutionary divergence.

The target sign: a significant CT sign for predicting small-bowel ischemia and necrosis

OBJECTIVE

To investigate the correlation between changes in the thickness and density of diseased small-bowel wall and small-bowel ischemia and necrosis (SBN) on CT imaging when small-bowel obstruction (SBO) occurs.

METHODS

We retrospectively analyzed 186 patients with SBO in our hospital from March 2020 to June 2023. The patients were divided into simple SBO (control group) and SBN (case group) groups. We used logistic regression analysis, the chi-square test, and Fisher's exact test to analyze the correlation between the changes in the thickness and density of the diseased intestinal wall and the SBN. A receiver operating characteristic (ROC) curve was used to calculate the accuracy of the multivariate analysis.

RESULTS

Of the 186 patients with SBO, 98 (52.7%) had simple SBO, 88 (47.3%) had SBN, and the rate of SBN was 47.3% (88/186). Multivariate regression analysis revealed that six CT findings were significantly correlated with SBN (p < 0.05), namely, thickening of the diseased intestinal wall with the target sign (OR = 21.615), thinning of the diseased intestinal wall (OR = 48.106), increase in the diseased intestinal wall density (OR = 13.696), mesenteric effusion (OR = 21.635), decrease in the diseased intestinal wall enhancement on enhanced scanning (OR = 41.662), and increase in the diseased intestinal wall enhancement on enhanced scanning (OR = 15.488). The AUC of the multivariate analysis reached 0.987 (95% CI 0.974-0.999). Specifically, the target sign was easily recognizable on CT images and was a significant CT finding for predicting SBN.

CONCLUSION

We identified 6 CT findings that were significantly associated with SBN, and may be helpful for clinical treatment.

The comparative anatomy of the petrosal bone and bony labyrinth of four small-sized deer

Here we provide complete 3D reconstructions of the petrosal bone and bony labyrinth of four kinds of small-sized deer (Elaphodus cephalophus, Muntiacus reevesi, Muntiacus muntjak, Hydropotes inermis) based on high-resolution CT scanning, and select one musk deer (Moschus moschiferus) as a comparative object. The petrosal bone and bony labyrinth of E. cephalophus are illustrated for the first time, as well as the petrosal bones of M. reevesi and H. inermis. Some morphological characters of petrosal bone and bony labyrinth can be used to distinguish the above-mentioned species. For example, M. moschiferus shows a prominent transpromontorial sulcus and a ventral basicapsular groove on the petrosal bone; there is a bifurcate cochlear aqueduct on the bony labyrinth of E. cephalophus; there is a distinct fusion between the lateral and posterior semicircular canals on the bony labyrinth of H. inermis. Meanwhile, there are some intraspecific variations on the subarcuate fossa, the tegmen tympani, the cochlear aqueduct, as well as the endolymphatic sac. Our results further confirm that the petrosal bone and bony labyrinth have enormous potential for taxonomy. This work will provide new anatomical data for the phylogenetic study of ruminants in the future, and it will be very practical to identify the isolated ruminants' petrosal bones that are frequently unearthed from paleontological or archeological sites.

Microscopic deposition-property relationships in microbial-induced consolidation of coal dusts

In recent years, the preparation of new microbial dust suppressants based on microbial induced carbonate precipitation (MICP) technology through enriched urease-producing microbial communities has become a new topic in the field of coal dust control. The deposition of CaCO3 was the key to suppress coal dust. However, deposition characteristics in the field is not sufficient and the relationship between deposition characteristics and erosion resistance is not clear, which hinders the development of engineering application of new microbial dust suppressant. Therefore, based on X-CT technology, this paper observed and quantified micro-deposition of bio-consolidated coal dust with different calcium sources. Furthermore, a conceptual framework for deposition was proposed and its correlation with erosion resistance was revealed. The results showed that CaCO3 induced by calcium chloride and calcium lactate was aggregate deposited. Aggregate deposited CaCO3 was small in volume, showed the distribution of aggregation in the central area and loose outside, and mosaiced pores. CaCO3 induced by calcium nitrate was surface deposition due to attached biomass. Surface deposition was mostly large volume CaCO3 expanding from the inside out, which could cover coal dust to a high degree and completely cemented pores. In addition, the threshold detachment velocity of coal dust cemented by surface deposition was increased by 17.6-19.1% compared to aggregate deposition. This depended on the abundance and strength of CaCO3 bonding between coal dust particles under different deposition. The two-factor model based on porosity and CaCO3 coverage can well express relationship between erosion resistance and depositional characteristics. Those results will help the engineering application of MICP technology in coal dust suppression.

Study on Fatigue Life of Aluminum Alloy 6061-T6 Based on Random Defect Characteristics

A certain number of hole-like defects will occur in aluminum alloys under cyclic loading. The internal holes will reduce the strength of the material and cause stress concentration, which will aggravate the development of fatigue damage. A classification method of defect features based on X-ray CT damage data is proposed. The random hole distribution model is established through the linear congruence method and the region division method. The hole parameter is introduced as the intermediate variable of the 3D reconstruction model of internal defects. In the mesoscopic stage, the function relationship between the distribution of random holes and the fatigue life is established based on the coupling relationship between the number and proportion of pores and the fatigue life. In the macroscopic stage, the relationship between the random holes and the macroscopic crack growth life is established by taking the crack length as the damage variable. The crack propagation rate decreased with the increase in the number of holes. The prediction model of the whole life stage is established using the life function from microcrack initiation to macroscopic crack propagation. Finally, the validity of the whole stage fatigue life prediction model is demonstrated through the comparison and verification of experiments, which provides a certain engineering value for the life estimation of 6061-T6 aluminum alloy materials.

Influence of High-Frequency Ultrasonic Vibration Load on Pore-Fracture Structure in Hard Rock: A Study Based on 3D Reconstruction Technology

Rock fracture is a macroscopic fracturing process resulting from the initiation and propagation of microscopic cracks. Therefore, it is crucial to comprehend the damage and fracture mechanism of rock under ultrasonic vibration by investigating the evolutionary pattern of the meso-pore fracture structure in response to high-frequency vibrational loads, as explored in this study. Standard red sandstone samples with a diameter of 50 mm and height of 100 mm were subjected to ultrasonic high-frequency vibration tests. NMR and CT scans were conducted on the rock samples at different stages of ultrasonic vibration excitation to obtain the corresponding transverse relaxation time (T2) spectra and CT scan images for each layer. The NMR test results revealed that smaller pores formed within the rock under high-frequency vibration loads, with a noticeable expansion observed in micropores. Three-dimensional reconstruction analysis based on two-dimensional CT images demonstrated an increase in pore count by 145.56%, 122.67%, and 98.87%, respectively, for the upper, middle, and lower parts of the rock after 120 s of ultrasonic vibration excitation; furthermore, the maximum pore volume increased by 239.42%, 109.16%, and 18.99%, respectively, for these regions during this period as well. These findings contribute towards a deeper understanding regarding the mechanisms underlying rock fragmentation when exposed to high-frequency vibrational loads.

Lateral line system diversification during the early stages of ecological speciation in cichlid fish

BACKGROUND

The mechanosensory lateral line system is an important sensory modality in fishes, informing multiple behaviours related to survival including finding food and navigating in dark environments. Given its ecological importance, we may expect lateral line morphology to be under disruptive selection early in the ecological speciation process. Here we quantify the lateral line system morphology of two ecomorphs of the cichlid fish Astatotilapia calliptera in crater Lake Masoko that have diverged from common ancestry within the past 1,000 years.

RESULTS

Based on geometric morphometric analyses of CT scans, we show that the zooplanktivorous benthic ecomorph that dominates the deeper waters of the lake has large cranial lateral line canal pores, relative to those of the nearshore invertebrate-feeding littoral ecomorph found in the shallower waters. In contrast, fluorescence imaging revealed no evidence for divergence between ecomorphs in the number of either superficial or canal neuromasts. We illustrate the magnitude of the variation we observe in Lake Masoko A. calliptera in the context of the neighbouring Lake Malawi mega-radiation that comprises over 700 species.

CONCLUSIONS

These results provide the first evidence of divergence in this often-overlooked sensory modality in the early stages of ecological speciation, suggesting that it may have a role in the broader adaptive radiation process.

Quantitate evaluation of photogrammetry with CT scanning for orbital defect

Facial deformities can be caused by cancer, tumours, trauma, infections, congenital or acquired defects and may lead to alteration in basic functions such as communication, breathing, and mastication and aesthetic thereby affecting quality of life. Traditional processes for manufacturing maxillofacial prostheses involve complicated, time-consuming and tedious processes for the patient and the operator. Impression of the defect area, which is the one of the crucial step in fabrication of prosthesis, is the longest and most difficult process as it requires a long contact with the patient. The digital revolution is now changing the landscape of prosthetic production and making the impression making procedure simpler. Digital technology reduces patient chair side time by providing more accurate display data in less time (3-5 min) than traditional methods. Digital impressions eliminate the need for bulky impression materials and provide a more comfortable patient experience.

Application of Computed Tomography Scanning Parameters Combined with Serum Cripto-1 in the Diagnosis of Renal Cell Carcinoma

OBJECTIVE

This study aims to analyse the clinical value of computed tomography (CT) scanning parameters combined with serum teratoma-derived growth factor-1 (Cripto-1) in the diagnosis of renal cell carcinoma (RCC).

METHODS

A retrospective analysis was conducted on 256 patients with renal tumour admitted to our hospital from July 2020 to December 2022. They were divided into malignant group (n = 180) and benign group (n = 76) based on the final pathological results. All subjects underwent CT scans and serum Cripto-1 testing. The CT signs and serum Cripto-1 levels of the patients were analysed, and their diagnostic efficacy was evaluated.

RESULTS

The pathological diagnosis results showed 180 cases of malignant tumours, including 73 cases of clear cell carcinoma, 60 cases of papillary RCC and 47 cases of chromophobe cell carcinoma as well as 76 cases of benign tumour, including 31 cases of renal angiomyolipoma, 25 cases of eosinophilic tumour and 20 cases of renal fibroma. The malignant group had significantly higher incidence of cystic necrosis, uneven enhancement and rapid progression than the benign group (p < 0.01). The incidence of calcification was not statistically different between the two groups (p > 0.05). The malignant group had lower CT value of focus (p < 0.01) and relative corrected CT value of the renal cortex (p < 0.05), and significantly higher serum levels of Cripto-1 (p < 0.01) than the malignant group. The area under the curve of the combined diagnosis was significantly higher than that of serum Cripto-1 alone and comprehensive diagnosis of CT parameters (pcombined diagnosis vs serum Cripto-1 < 0.001, pcombined diagnosis vs comprehensive diagnosis of CT parameters = 0.002). The sensitivity of the combined diagnosis was also higher than that of serum Cripto-1 and CT parameters alone.

CONCLUSIONS

The combination of CT scanning parameters and serum Cripto-1 has high value in the diagnosis of renal tumours, and the area under the curve and sensitivity of the combined diagnosis are high. This work provides reference for clinical diagnosis and treatment of renal tumours.

Surface Evaluation of Gyroid Structures for Manufacturing Rubber-Textile Conveyor Belt Carcasses Using Micro-CT

Gyroid structures are among the most widely used three-dimensional elements produced by various additive manufacturing technologies. This paper focuses on a metrological analysis of Flexfill 92A material specimens with a relative density (25 to 85%) using industrial computer tomography. The results show that for a given structure, the best method is to use surface determination with the closure of internal defects in the material. The analysis implies that the smallest deviations of the specimens' external dimensions were achieved with respect to the CAD model at the highest relative densities. The wall thickness shows the smallest percentage change of 0.5685 at 45% relative density and the largest at 25% and 85% relative density. The nominal-actual comparison of manufactured specimens to the CAD model shows the smallest cumulative deviation of 0.209 mm at 90% and 25% relative density, while it slightly increases with increasing relative density. All produced specimens have a smaller material volume than their theoretical volume value, while the percentage change in volume is up to 8.6%. The surface of specimens is larger compared with the theoretical values and the percentage change reaches up to 25.3%. The percentage of pores in the specimens increases with increasing relative density and reaches 6%. The acquired knowledge will be applied in the framework of research focused on the possibilities of using additive manufacturing to produce a skeleton of rubber-textile conveyor belts. This paper presents initial research on the possibility of replacing the carcass of rubber-textile belts with an additive technology use.

Timing of computed tomography imaging in adult patients with severe trauma: A nationwide cohort study in Japan

PURPOSE

Computed tomography (CT) has become essential for the management of trauma patients. However, appropriate timing of CT acquisition remains undetermined. The purpose of this study was to assess the relationship between time to CT acquisition and mortality among adult patients with severe trauma.

METHODS

We conducted a retrospective cohort study using data from the Japan Trauma Data Bank, which had 256 participating institutions from all over Japan between 2004 and 2018. Patients were categorized upon arrival as either severe trunk trauma with signs of shock or severe head trauma with coma and separately analyzed. Cases were further divided into three groups based on time elapsed between arrival at hospital and CT acquisition as immediate (0-29 min), intermediate (30-59 min), or late (≥60 min). Primary outcome was mortality on discharge, and multivariate logistic regression with adjusting for confounders was used for evaluation.

RESULTS

A total of 8467 (3640 in immediate group, 3441 in intermediate group, 1386 in late group) with trunk trauma patients and 6762 (4367 in immediate group, 2031 in intermediate group, 364 in late group) with head trauma patients were eligible for analysis included in the trunk and head trauma groups, respectively. The trunk trauma patients with shock on hospital arrival was 56.4% (4773/8467), and the head trauma patients with deep coma upon EMS arrival was 44.2% (2988/6762). Mortality rate gradually increased from 5.7% to 15.8% with prolonged time to CT imaging among trunk trauma patients. Multivariate logistic regression for death on discharge among trunk trauma patients yielded an adjusted odds ratio of 1.79 (95% confidence interval: 1.42-2.27) for the late group compared to the immediate group. In contrast, among head trauma patients, an adjusted odds ratio was 0.93 (95% confidence interval: 0.71-1.20) for the late group compared to the immediate group.

CONCLUSION

CT scan at or after 60 min was associated with increased death on discharge among patients with severe trunk trauma but not in those with severe head trauma.

Prognostic Value of Serum Biomarkers in Patients With Moderate-Severe Traumatic Brain Injury, Differentiated by Marshall Computer Tomography Classification

Prognostication is challenging in patients with traumatic brain injury (TBI) in whom computed tomography (CT) fails to fully explain a low level of consciousness. Serum biomarkers reflect the extent of structural damage in a different way than CT does, but it is unclear whether biomarkers provide additional prognostic value across the range of CT abnormalities. This study aimed to determine the added predictive value of biomarkers, differentiated by imaging severity. This prognostic study used data from the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI) study (2014-2017). The analysis included patients aged ≥16 years with a moderate-severe TBI (Glasgow Coma Scale [GCS] <13) who had an acute CT and serum biomarkers obtained ≤24h of injury. Of six protein biomarkers (GFAP, NFL, NSE, S100B, Tau, UCH-L1), the most prognostic panel was selected using lasso regression. The performance of established prognostic models (CRASH and IMPACT) was assessed before and after the addition of the biomarker panel and compared between patients with different CT Marshall scores (Marshall score <3 vs. Marshall score ≥3). Outcome was assessed at six months post-injury using the extended Glasgow Outcome Scale (GOSE), and dichotomized into favorable and unfavorable (GOSE <5). We included 872 patients with moderate-severe TBI. The mean age was 47 years (range 16-95); 647 (74%) were male and 438 (50%) had a Marshall CT score <3. The serum biomarkers GFAP, NFL, S100B and UCH-L1 provided complementary prognostic information; NSE and Tau showed no added value. The addition of the biomarker panel to established prognostic models increased the area under the curve (AUC) by 0.08 and 0.03, and the explained variation in outcome by 13-14% and 7-8%, for patients with a Marshall score of <3 and ≥3, respectively. The incremental AUC of biomarkers for individual models was significantly greater when the Marshall score was <3 compared with ≥3 (p < 0.001). Serum biomarkers improve outcome prediction after moderate-severe TBI across the range of imaging severities and especially in patients with a Marshall score <3.

Clinical Utility of Near-Infrared Device in Detecting Traumatic Intracranial Hemorrhage: A Pilot Study Toward Application as an Emergent Diagnostic Modality in a Low-Resource Setting

Limited computed tomography (CT) availability in low- and middle-income countries frequently impedes life-saving neurosurgical decompression for traumatic brain injury. A reliable, accessible, cost-effective solution is necessary to detect and localize bleeds. We report the largest study to date using a near-infrared device (NIRD) to detect traumatic intracranial bleeds. Patients with confirmed or suspected head trauma who received a head CT scan were included. Within 30 min of the initial head CT scan, a blinded examiner scanned each patient's cranium with a NIRD, interrogating bilaterally the frontal, parietal, temporal, and occipital quadrants Sensitivity, specificity, accuracy, and precision were investigated. We recruited 500 consecutive patients; 104 patients had intracranial bleeding. For all patients with CT-proven bleeds, irrespective of size, initial NIRD scans localized the bleed to the appropriate quadrant with a sensitivity of 86% and specificity of 96% compared with CT. For extra-axial bleeds >3.5mL, sensitivity and specificity were 94% and 96%, respectively. For longitudinal serial rescans with the NIRD, sensitivity was 89% (< 4 days from injury: sensitivity: 99%), and specificity was 96%. For all patients who required craniectomy or craniotomy, the device demonstrated 100% sensitivity. NIRD is highly sensitive, specific, and reproducible over time in diagnosing intracranial bleeds. NIRD may inform neurosurgical decision making in settings where CT scanning is unavailable or impractical.

Sleep Apnea Combined with Pulmonary Hypertension in a Veteran Patient Population

We have investigated the concurrence of sleep apnea and pulmonary hypertension in a Veteran population. We retrospectively reviewed 142 patients who underwent chest CT scans and had a dilated main pulmonary artery, defined as a width exceeding 29 mm on axial images. Approximately 40% of patients with pulmonary hypertension had associated sleep apnea. No significant difference in pulmonary artery diameters could be found between the group without sleep apnea and the group with sleep apnea (34.5 ± 4.2 mm vs. 34.7 ± 4.4 mm, p = 0.373).

Performance Evaluation and Oil Displacement Effect of Amphiphilic Polymer Heavy Oil Activator

A heavy oil activator is an amphiphilic polymer solution that contains hydrophilic and oleophobic groups. It can enhance heavy oil recovery efficiency. This paper studied the changes in the distribution of the remaining oil after activator flooding and the performance of heavy oil's active agent. Nuclear magnetic resonance spectroscopy, laser confocal microscopy, microscopic visualization, and CT scanning techniques were used to analyze crude oil utilization, and the distribution characteristics of the remaining oil during activator flooding of heavy oil. The results showed that the heavy oil activator solution presented a dense spatial network and good viscosification ability. The activator could reduce the interfacial tension of oil and water, disassemble the heavy components of dispersed heavy oil and reduce the viscosity of heavy oil. The utilization degree of the remaining oil in small and middle pores increased significantly after activator flooding, the remaining oil associated with membranous-like and clusterlike structures was utilized to a high degree, and the decline of light/heavy fraction in heavy oil slowed down. Heavy oil activator improved the swept volume and displacement efficiency of heavy oil, playing a significant role in improving the extent of recovery of heavy oil reservoirs.

Using computed tomography to recover hidden medieval fragments beneath early modern leather bindings, first results

Medieval bindings fragments have become increasingly interesting to Humanities researchers as sources for the textual and material history of medieval Europeans. Later book binders used these discarded and repurposed pieces of earlier medieval manuscripts to reinforce the structures of other manuscripts and printed books. That many of these fragments are contained within and obscured by decorative bindings that cannot be dismantled ethically has limited their discovery and description. Although previous attempts to recover these texts using IRT and MA-XRF scanning have been successful, the extensive time required to scan a single book, and the need to modify or create specialized IRT or MA-XRF equipment for this method are drawbacks. Our research proposes and tests the capabilities of medical CT scanning technologies (commonly available at research university medical schools) for making visible and legible these fragments hidden under leather bindings. Our research team identified three sixteenth-century printed codices in our university libraries that were evidently bound in tawed leather by one workshop. The damaged cover of one of these three had revealed medieval manuscript fragments on the book spine; this codex served as a control for testing the other two volumes to see if they, too, contain fragments. The use of a medical CT scanner proved successful in visualizing interior book-spine structures and some letterforms, but not all of the text was made visible. The partial success of CT-scanning points to the value of further experimentation, given the relatively wide availability of medical imaging technologies, with their potential for short, non-destructive, 3D imaging times.

Compartmentalized Quantitative Analysis of Concrete Sulfate-Damaged Area Based on Ultrasonic Velocity

The corrosion of concrete in sulfate environments is a difficult problem in the durability of civil engineering structures. To investigate the variability of deterioration damage to concrete structures by sulfate erosion under non-destructive testing and quantify the protective effect of silane coatings on concrete under the action of sulfate erosion, an accelerated erosion experiment was carried out using field sampling in a tunnel project under a sulfate erosion environment. By means of ultrasonic velocity measurement and CT scanning, the samples protected by a silane coating under the sulfate attack environment were compared with those not protected. The deterioration characteristics of concrete under the sulfate attack environment and the protective effect of silane coating on the concrete structure were analyzed. In addition, a method for evaluating the sulfate damage to concrete based on CT images and ultrasonic velocity analysis was proposed. The results show that the samples prepared in the field show a significant difference in ultrasonic velocity in the process of erosion and deterioration according to the material difference at the measuring point interface. Through the overall damage evaluation analysis of the sample, it is concluded that the damage degree of the protected group sample is light and the heterogeneity is weak, whereas the local damage to the exposed group is serious. Combined with the CT image analysis of concrete before and after loading, the distribution characteristics of the damaged area divided by the concrete sulfate damage evaluation method proposed in this paper are highly similar to the real situation. The results of the study can provide a reference for similar projects for the detection, analysis, protection and evaluation of sulfate-attacked concrete.

Experimental Study of the Propagation Process of Dissection Using an Aortic Silicone Phantom

BACKGROUND

The mortality of acute aortic dissection (AD) can reach 65~70%. However, it is challenging to follow the progress of AD formation. The purpose of this work was to observe the process of dissection development using a novel tear-embedded silicone phantom.

METHODS

Silicone phantoms were fabricated by embedding a torn area and primary tear feature on the inner layer. CT scanning and laser lightening were conducted to observe the variations in thickness and volume of the true lumen (TL) and false lumen (FL) during development.

RESULTS

The model with a larger interlayer adhesion damage required a lower pressure to trigger the development of dissection. At the initiation stage of dissection, the volume of TL increased by 25.5%, accompanied by a 19.5% enlargement of tear size. The force analysis based on the change of tear size verified the deduction of the process of interlaminar separation from the earlier studies.

CONCLUSIONS

The primary tear and the weakening adhesion of the vessel layers are key factors in AD development, suggesting that some forms of primary damage to the arterial wall, in particular, the lumen morphology of vessels with straight inner lumen, should be considered as early risk predictors of AD.

Associations of the MUC5B promoter variant with timing of interstitial lung disease and rheumatoid arthritis onset

OBJECTIVES

To investigate the associations of the common MUC5B promoter variant with timing of RA-associated interstitial lung disease (RA-ILD) and RA onset.

METHODS

We identified patients with RA meeting 2010 ACR/EULAR criteria and available genotype information in the Mass General Brigham Biobank, a multihospital biospecimen and clinical data collection research study. We determined RA-ILD presence by reviewing all RA patients who had CT imaging, lung biopsy or autopsy results. We determined the dates of RA and RA-ILD diagnoses by manual records review. We examined the associations of the MUC5B promoter variant (G>T at rs35705950) with RA-ILD, RA-ILD occurring before or within 2 years of RA diagnosis and RA diagnosis at age >55 years. We used multivariable logistic regression to estimate odds ratios (ORs) for each outcome by MUC5B promoter variant status, adjusting for potential confounders including genetic ancestry and smoking.

RESULTS

We identified 1005 RA patients with available genotype data for rs35705950 (mean age 45 years, 79% female, 81% European ancestry). The MUC5B promoter variant was present in 155 (15.4%) and was associated with RA-ILD [multivariable OR 3.34 (95% CI 1.97, 5.60)], RA-ILD before or within 2 years of RA diagnosis [OR 4.01 (95% CI 1.78, 8.80)] and RA onset after age 55 years [OR 1.52 (95% CI 1.08, 2.12)].

CONCLUSIONS

The common MUC5B promoter variant was associated with RA-ILD onset earlier in the RA disease course and older age of RA onset. These findings suggest that the MUC5B promoter variant may impact RA-ILD risk early in the RA disease course, particularly in patients with older-onset RA.

Validating the use of 3D biplanar radiography versus CT when measuring femoral anteversion after total hip arthroplasty : a comparative study

AIMS

Although CT is considered the benchmark to measure femoral version, 3D biplanar radiography (hipEOS) has recently emerged as a possible alternative with reduced exposure to ionizing radiation and shorter examination time. The aim of our study was to evaluate femoral stem version in postoperative total hip arthroplasty (THA) patients and compare the accuracy of hipEOS to CT. We hypothesize that there will be no significant difference in calculated femoral stem version measurements between the two imaging methods.

METHODS

In this study, 45 patients who underwent THA between February 2016 and February 2020 and had both a postoperative CT and EOS scan were included for evaluation. A fellowship-trained musculoskeletal radiologist and radiological technician measured femoral version for CT and 3D EOS, respectively. Comparison of values for each imaging modality were assessed for statistical significance.

RESULTS

Comparison of the mean postoperative femoral stem version measurements between CT and 3D hipEOS showed no significant difference (p = 0.862). In addition, the two version measurements were strongly correlated (r = 0.95; p < 0.001), and the mean paired difference in postoperative femoral version for CT scan and 3D biplanar radiography was -0.09° (95% confidence interval -1.09 to 0.91). Only three stem measurements (6.7%) were considered outliers with a > 5° difference.

CONCLUSION

Our study supports the use of low-dose biplanar radiography for the postoperative assessment of femoral stem version after THA, demonstrating high correlation with CT. We found no significant difference for postoperative femoral version when comparing CT to 3D EOS. We believe 3D EOS is a reliable option to measure postoperative femoral version given its advantages of lower radiation dosage and shorter examination time.Cite this article: Bone Joint J 2022;104-B(11):1196-1201.

Comprehensive Testing of Sulfate Erosion Damage of Concrete Structures and Analysis of Silane Coating Protection Effect

In order to study the protection performance of silane coating on in-service concrete structures in a sulfate environment, we collect concrete samples in the field to simulate the concrete erosion process by accelerated erosion with wetting-drying cycles. We place the samples into protected, exposed and control groups corresponding to a corrosive environment with silane protection, corrosive environment without protection and general environment for three different service conditions. A combination of ultrasonic velocimetry, CT (Computed Tomography) scan imaging, NMR (Nuclear Magnetic Resonance) pore structure analysis, strength testing and other methods are used to analyze the strength, ultrasonic wave velocity, pore structure and other characteristics of the specimens during sulfate erosion. Based on the test results, the protective effect of silane coating on concrete structures under sulfate attack is quantitatively analyzed, and an index for judging the damage rate of specimens is proposed to quantitatively analyze the protective effect of silane coating. The research results show that the damage of the concrete structure under silane protection in a sulfate-attack environment can be reduced by more than 50%; its integrity damage index and strength damage index are easily affected by the location of local defects, which leads to a decrease in the protection efficiency of the surface silane coating.

Anatomy and relationships of the early diverging Crocodylomorphs Junggarsuchus sloani and Dibothrosuchus elaphros

The holotype of Junggarsuchus sloani, from the Shishugou Formation (early Late Jurassic) of Xinjiang, China, consists of a nearly complete skull and the anterior half of an articulated skeleton, including the pectoral girdles, nearly complete forelimbs, vertebral column, and ribs. Here, we describe its anatomy and compare it to other early diverging crocodylomorphs, based in part on CT scans of its skull and that of Dibothrosuchus elaphros from the Early Jurassic of China. Junggarsuchus shares many features with a cursorial assemblage of crocodylomorphs, informally known as "sphenosuchians," whose relationships are poorly understood. However, it also displays several derived crocodyliform features that are not found among most "sphenosuchians." Our phylogenetic analysis corroborates the hypothesis that Junggarsuchus is closer to Crocodyliformes, including living crocodylians, than are Dibothrosuchus and Sphenosuchus, but not as close to crocodyliforms as Almadasuchus and Macelognathus, and that the "Sphenosuchia" are a paraphyletic assemblage. D. elaphros and Sphenosuchus acutus are hypothesized to be more closely related to Crocodyliformes than are the remaining non-crocodyliform crocodylomorphs, which form several smaller groups but are largely unresolved.

Reconstruction of Paprosky III defects with custom-made implants: do we get them in the correct position? : short-term radiological results

AIMS

The aim of this study was to examine the implant accuracy of custom-made partial pelvis replacements (PPRs) in revision total hip arthroplasty (rTHA). Custom-made implants offer an option to achieve a reconstruction in cases with severe acetabular bone loss. By analyzing implant deviation in CT and radiograph imaging and correlating early clinical complications, we aimed to optimize the usage of custom-made implants.

METHODS

A consecutive series of 45 (2014 to 2019) PPRs for Paprosky III defects at rTHA were analyzed comparing the preoperative planning CT scans used to manufacture the implants with postoperative CT scans and radiographs. The anteversion (AV), inclination (IC), deviation from the preoperatively planned implant position, and deviation of the centre of rotation (COR) were explored. Early postoperative complications were recorded, and factors for malpositioning were sought. The mean follow-up was 30 months (SD 19; 6 to 74), with four patients lost to follow-up.

RESULTS

Mean CT defined discrepancy (Δ) between planned and achieved AV and IC was 4.5° (SD 3°; 0° to 12°) and 4° (SD 3.5°; 1° to 12°), respectively. Malpositioning (Δ > 10°) occurred in five hips (10.6%). Native COR reconstruction was planned in 42 cases (93%), and the mean 3D deviation vector was 15.5 mm (SD 8.5; 4 to 35). There was no significant influence in malpositioning found for femoral stem retention, surgical approach, or fixation method.

CONCLUSION

At short-term follow-up, we found that PPR offers a viable solution for rTHA in cases with massive acetabular bone loss, as highly accurate positioning can be accomplished with meticulous planning, achieving anatomical reconstruction. Accuracy of achieved placement contributed to reduced complications with no injury to vital structures by screw fixation.Cite this article: Bone Joint J 2022;104-B(10):1110-1117.

Anthracene Single-Crystal Scintillators for Computer Tomography Scanning

X-ray imaging and computed tomography (CT) technology, as the important non-destructive measurements, can observe internal structures without destroying the detected sample, which are always used in biological diagnosis to detect tumors, pathologies, and bone damages. It is always a challenge to find materials with a low detection limit, a short exposure time, and high resolution to reduce X-ray damage and acquire high-contrast images. Here, we described a low-cost and high-efficient method to prepare centimeter-sized anthracene crystals, which exhibited intense X-ray radioluminescence with a detection limit of ∼0.108 μGy s^-1, which is only one-fifth of the dose typically used for X-ray diagnostics. Additionally, the low absorption reduced the damage in radiation and ensured superior cycle performance. X-ray detectors based on anthracene crystals also exhibited an extremely high resolution of 40 lp mm^-1. The CT scanning and reconstruction of a foam sample were then achieved, and the detailed internal structure could be clearly observed. These indicated that organic crystals are expecting to be leading candidate low-cost materials for low-dose and highly sensitive X-ray detection and CT scanning.

COVID-19 Diagnosis and Classification Using Radiological Imaging and Deep Learning Techniques: A Comparative Study

In December 2019, the novel coronavirus disease 2019 (COVID-19) appeared. Being highly contagious and with no effective treatment available, the only solution was to detect and isolate infected patients to further break the chain of infection. The shortage of test kits and other drawbacks of lab tests motivated researchers to build an automated diagnosis system using chest X-rays and CT scanning. The reviewed works in this study use AI coupled with the radiological image processing of raw chest X-rays and CT images to train various CNN models. They use transfer learning and numerous types of binary and multi-class classifications. The models are trained and validated on several datasets, the attributes of which are also discussed. The obtained results of various algorithms are later compared using performance metrics such as accuracy, F1 score, and AUC. Major challenges faced in this research domain are the limited availability of COVID image data and the high accuracy of the prediction of the severity of patients using deep learning compared to well-known methods of COVID-19 detection such as PCR tests. These automated detection systems using CXR technology are reliable enough to help radiologists in the initial screening and in the immediate diagnosis of infected individuals. They are preferred because of their low cost, availability, and fast results.

Review of COVID-19 testing and diagnostic methods

More than six billion tests for COVID-19 has been already performed in the world. The testing for SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus-2) virus and corresponding human antibodies is essential not only for diagnostics and treatment of the infection by medical institutions, but also as a pre-requisite for major semi-normal economic and social activities such as international flights, off line work and study in offices, access to malls, sport and social events. Accuracy, sensitivity, specificity, time to results and cost per test are essential parameters of those tests and even minimal improvement in any of them may have noticeable impact on life in the many countries of the world. We described, analyzed and compared methods of COVID-19 detection, while representing their parameters in 22 tables. Also, we compared test performance of some FDA approved test kits with clinical performance of some non-FDA approved methods just described in scientific literature. RT-PCR still remains a golden standard in detection of the virus, but a pressing need for alternative less expensive, more rapid, point of care methods is evident. Those methods that may eventually get developed to satisfy this need are explained, discussed, quantitatively compared. The review has a bioanalytical chemistry prospective, but it may be interesting for a broader circle of readers who are interested in understanding and improvement of COVID-19 testing, helping eventually to leave COVID-19 pandemic in the past.

Comparison of Application Value of Different Radiation Dose Evaluation Methods in Evaluating Radiation Dose of Adult Thoracic and Abdominal CT Scan

Objective

To explore the differences among volumetric CT dose index (CTDI_vol), body-specific dose assessment (SSDE_ED) based on effective diameter (ED), and SSDE_WED based on water equivalent diameter (WED) in evaluating the radiation dose of adult thoracic and abdominal CT scanning.

Methods

From January 2021 to October 2021, enhanced chest CT scans of 100 patients and enhanced abdomen CT scans of another 100 patients were collected. According to the body mass index (BMI), they can be divided into groups A and D (BMI < 20 kg/m²), groups B and E (20 kg/m² ≤ BMI ≤ 24.9 kg/m²), and groups C and F (BMI > 24.9 kg/m²). The CTDIvol, anteroposterior diameter (AP), and the left and rght diameter (LAT) of all the patients were recorded, and the ED, water equivalent diameter (WED), the conversion factor (f _size,ED), (f _{size, WED}), SSDE_ED, and SSDE_WED were calculated. The differences were compared between the different groups.

Results

The AP, LAT, ED, and WED of groups B, E, C, and F were higher than those of groups A and D, and those of groups C and F were higher than those of groups B and E (P < 0.05). The f _size,ED and f _{size, WED} of groups B, E, C, and F are lower than those of groups A and D, and those of groups C and F are lower than those of groups B and E (P < 0.05). CTDI_vol, SSDE_ED, and SSDE_WED in groups B, E, C, and F are higher than those in groups A and D, and those in groups C and F are higher than those in groups B and E (p < 0.05). In the same group, patients with chest- and abdomen-enhanced have higher SSDE_WED and SSDE_ED than CTDI_vol, patients with chest-enhanced CT scans have higher SSDE_WED than SSDE_ED, and patients with abdomen-enhanced CT scans have higher SSDE_ED than SSDE_WED (P < 0.05).

Conclusion

CTDIvol and ED-based SSDEED underestimated the radiation dose of the subject exposed, where the patient was actually exposed to a greater dose. However, SSDE_WED based on WED considers better the difference in patient size and attenuation characteristics, and can more accurately evaluate the radiation dose received by patients of different sizes during the chest and abdomen CT scan.

Impact of multidetector computed tomography scan parameters, novel reconstruction settings, and lung nodule characteristics on nodule diameter measurements: A Phantom Study

PURPOSE

Novel CT reconstruction techniques strive to maintain image quality and processing efficiency. The purpose of this study is to investigate the impact of a newer hybrid iterative reconstruction technique, Adaptive Statistical Iterative Reconstruction-V (ASIR-V) in combination with various CT scan parameters on the semi-automated quantification using various lung nodules.

METHODS

A chest phantom embedded with eight spherical objects was scanned using varying CT parameters such as tube current and ASIR-V levels. We calculated absolute percentage error (APE) and mean APE (MAPE) using differences between the semi-automated measured diameters and known dimensions. Predictive variables were assessed using a multivariable general linear model. The linear regression slope coefficients (β) were reported to demonstrate effect size and directionality.

RESULTS

The APE of the semi-automated measured diameters was higher in ground-glass than solid nodules (β = 9.000, p<0.001). APE had an inverse relationship with nodule diameter (mm; β = -3.499, p<0.001) and tube current (mA; β = -0.006, p<0.001). MAPE did not vary based on the ASIR-V level (range: 5.7-13.1%).

CONCLUSION

Error is dominated by nodule characteristics with a small effect of tube current. Regardless of phantom size, nodule size accuracy is not affected by tube voltage or ASIR-V level, maintaining accuracy while maximizing radiation dose reduction. This article is protected by copyright. All rights reserved.

Study on fracture behavior of molars based on three-dimensional high-precision computerized tomography scanning and numerical simulation

A series of three-dimensional (3D) numerical simulations are conducted to investigate the gradual failure process of molars in this study. The real morphology and internal mesoscopic structure of a whole tooth are implemented into the numerical simulations through computerized tomography scanning, digital image processing, and 3D matrix mapping. The failure process of the whole tooth subject to compressions including crack initiation, crack propagation, and final failure pattern is reproduced using 3D realistic failure process analysis (RFPA3D) method. It is concluded that a series of microcracks are gradually initiated, nucleated, and subsequently interconnect to form macroscopic cracks when the teeth are under over-compressions. The propagation of the macroscopic cracks results in the formation of fracture surfaces and penetrating cracks, which are essential signs and manifestations of the tooth failure. Moreover, the simulations reveal that, the material heterogeneity is a critical factor that affects the mechanical properties and fracture modes of the teeth, which vary from crown fractures to crown-root fractures and root fractures depending on different homogeneity indices.

Ankle structure of the Tokay gecko (Gekko gecko) and its role in the deployment of the subdigital adhesive system

The remarkable ability of geckos to adhere to smooth surfaces is often thought of in terms of external structures, including the branching setae that make contact with the surface producing van der Waals forces. Some geckos also exhibit unique movements of the distal segments of the limbs during locomotion and static clinging, including active digital hyperextension and considerable pedal rotation. During static clinging, geckos can exhibit considerable adduction/abduction of the pes while the crus and thigh remain firmly adpressed to the substratum. This decoupling of pedal adduction/abduction from ankle flexion/extension and pedal long-axis rotation is a significant departure from pedal displacements of a typical lizard lacking adhesive ability. The structure of the ankle is likely key to this decoupling, although no detailed comparison of this complex joint between pad-bearing geckos and other lizards is available. Here we compare the configuration of the mesotarsal joint of nongekkotan lizards (Iguana and Pristidactylus) with that of the Tokay gecko (Gekko gecko) using prepared skeletons, scanning electron microscopy, and micro-computed tomographic (µCT) scans. We focus on the structure of the astragalocalcaneum and the fourth distal tarsal. The mesotarsal joint exhibits a suite of modifications that are likely associated with the secondarily symmetrical pes of pad-bearing geckos. For example, the lateral process of the astragalocalcaneum is much more extensive in G. gecko compared with other lizards. The mesotarsal joint exhibits several other differences permitting dissociation of long-axis rotation of the pes from flexion-extension movement, including a reduced ventral peg on the fourth distal tarsal, an articulatory pattern dominated by a well-defined, expansive distomesial notch of the astragalocalcaneum, and an associated broad proximodorsal articulatory facet of the fourth distal tarsal. Pad-bearing geckos are capable of effectively deploying their intricate adhesive system across a broad array of body angles because of this highly modified ankle. Future research should determine whether the differences encountered in G. gecko (and their extent) apply to the Gekkota as a whole and should examine how the elements of the ankle move dynamically during locomotion across a range of taxa.

Pilot study of micromotion nailing for mechanical stimulation of tibial fracture healing

Aims

The study objective was to prospectively assess clinical outcomes for a pilot cohort of tibial shaft fractures treated with a new tibial nailing system that produces controlled axial interfragmentary micromotion. The hypothesis was that axial micromotion enhances fracture healing compared to static interlocking.

Methods

Patients were treated in a single level I trauma centre over a 2.5-year period. Group allocation was not randomized; both the micromotion nail and standard-of-care static locking nails (control group) were commercially available and selected at the discretion of the treating surgeons. Injury risk levels were quantified using the Nonunion Risk Determination (NURD) score. Radiological healing was assessed until 24 weeks or clinical union. Low-dose CT scans were acquired at 12 weeks and virtual mechanical testing was performed to objectively assess structural bone healing.

Results

A total of 37 micromotion patients and 46 control patients were evaluated. There were no significant differences between groups in terms of age, sex, the proportion of open fractures, or NURD score. There were no nonunions (0%) in the micromotion group versus five (11%) in the control group. The proportion of fractures united was significantly higher in the micromotion group compared to control at 12 weeks (54% vs 30% united; p = 0.043), 18 weeks (81% vs 59%; p = 0.034), and 24 weeks (97% vs 74%; p = 0.005). Structural bone healing scores as assessed by CT scans tended to be higher with micromotion compared to control and this difference reached significance in patients who had biological comorbidities such as smoking.

Conclusion

In this pilot study, micromotion fixation was associated with improved healing compared to standard tibial nailing. Further prospective clinical studies will be needed to assess the strength and generalizability of any potential benefits of micromotion fixation.

Cite this article: Bone Jt Open 2021;2(10):825–833.

Vascular imaging of patients with refractory Takayasu arteritis treated with tocilizumab: post hoc analysis of a randomized controlled trial

OBJECTIVES

Tocilizumab, an anti-interleukin-6 receptor antibody, was investigated in patients with refractory Takayasu arteritis (TAK) in a phase 3 randomized controlled trial. In this post hoc analysis, we investigated whether tocilizumab treatment inhibited the progression of vascular lesions caused by TAK in these patients.

METHODS

Included patients received at least one dose of tocilizumab and underwent computed tomography (CT) at baseline and at week 48 after tocilizumab initiation. Three radiologists not involved in the original trial independently evaluated the CT images. Twenty-two arteries from each patient were assessed for change from baseline in wall thickness (primary end point), dilatation/aneurysm, stenosis/occlusion or wall enhancement for at least 96 weeks after tocilizumab initiation. Patient-level assessments were also conducted.

RESULTS

In 28 patients, 86.7% of 22 arteries had improved/stable wall thickness at week 96. Proportions of patients with improved/stable, partially progressed or newly progressed lesions were 57.1%, 10.7% and 28.6% for wall thickness; proportions with improved/stable lesions were 92.9% for dilatation/aneurysm and 85.7% for stenosis/occlusion. Patients with newly progressed lesions, reflecting more refractory disease, were prescribed glucocorticoids at dosages that could not be reduced below 0.1 mg/kg/day at week 96.

CONCLUSIONS

∼60% of patients with TAK did not experience progression in wall thickness within 96 weeks after initiation of tocilizumab treatment. Few patients experienced progressed dilatation/aneurysm or stenosis/occlusion. Wall thickness progression likely resulted from refractory TAK. Patients who experience this should be monitored regularly by imaging, and additional glucocorticoid or immunosuppressive treatment should be considered to avoid vascular progression.

A systematic review and meta-analysis to inform cancer screening guidelines in idiopathic inflammatory myopathies

Objectives

To identify clinical factors associated with cancer risk in the idiopathic inflammatory myopathies (IIMs) and to systematically review the existing evidence related to cancer screening.

Methods

A systematic literature search was carried out on Medline, Embase and Scopus. Cancer risk within the IIM population (i.e. not compared with the general population) was expressed as risk ratios (RR) for binary variables and weighted mean differences (WMD) for continuous variables. Evidence relating to cancer screening practices in the IIMs were synthesized via narrative review.

Results

Sixty-nine studies were included in the meta-analysis. DM subtype (RR 2.21), older age (WMD 11.19), male sex (RR 1.53), dysphagia (RR 2.09), cutaneous ulceration (RR 2.73) and anti-transcriptional intermediary factor-1 gamma positivity (RR 4.66) were identified as being associated with significantly increased risk of cancer. PM (RR 0.49) and clinically amyopathic DM (RR 0.44) subtypes, Raynaud’s phenomenon (RR 0.61), interstitial lung disease (RR 0.49), very high serum creatine kinase (WMD −1189.96) or lactate dehydrogenase (WMD −336.52) levels, and anti-Jo1 (RR 0.45) or anti-EJ (RR 0.17) positivity were identified as being associated with significantly reduced risk of cancer. Nine studies relating to IIM-specific cancer screening were included. CT scanning of the thorax, abdomen and pelvis appeared to be effective in identifying underlying asymptomatic cancers.

Conclusion

Cancer risk factors should be evaluated in patients with IIM for risk stratification. Screening evidence is limited but CT scanning could be useful. Prospective studies and consensus guidelines are needed to establish cancer screening strategies in IIM patients.

The anatomy of the palate in Early Triassic Chaohusaurus brevifemoralis (Reptilia: Ichthyosauriformes) based on digital reconstruction

The palatal anatomy of ichthyosauriforms remains largely unknown. Here, the complete palate of the early-branching ichthyosauriform Chaohusaurus brevifemoralis is reconstructed and described for the first time with the assistance of high-resolution X-ray computed tomography (CT) scanning on the basis of the three-dimensionally preserved skull of its paratype (GMPKU-P-3086) from the Lower Triassic of South China. The reconstruction reveals new palatal features of C. brevifemoralis. The palatine contacts the jugal directly, which is observed in ichthyosauriforms for the first time. A single row of denticles is present on each side of the palate. The vomer exceeds the anterior and posterior margins of the internal naris. The pterygoid is posterior to the internal naris. The epipterygoid is present and the ectopterygoid is absent.

Preoperative tumour size as a predictor of the presence of lymphovascular invasion in lung adenocarcinoma

Aim To examine whether preoperative tumour size may serve as a biomarker for the occurrence of lymphovascular invasion (LVI) in centrally and peripherally located lung adenocarcinoma. Method The study included 261 patients surgically treated for diagnosed lung adenocarcinoma. A ROC curve was used to determine the biomarker potential of tumour size relative to the occurrence of LVI. Binary logistic regression was used to show changes of tumour size impact on the status of LVI. Result Tumour prevalence according to localization had no statistical significance (p=0.464), while the presence of LVI in central, as well as peripheral positions, was statistically significantly different (p<0.001). The area under the curve of 0.978 highlights the fact that tumour size is an excellent marker of the presence of LVI in centrally located adenocarcinomas of the lung. A similar finding was confirmed in peripherally located lung adenocarcinomas with an area below the curve of 0.943. Binary logistical regression showed that in centrally localized adenocarcinomas of the lung, each additional centimetre of tumour growth represents an increase in the likelihood of LVI+ by 17.14 times. In peripherally located adenocarcinomas of the lung, this increase in likelihood of LVI for each centimetre of growth was 5.46 times. Conclusion With a high degree of sensitivity and specificity, preoperative tumour size may serve as an important biomarker and positive predictor of the presence of LVI in lung adenocarcinoma of any location.

Advanced imaging for quantification of abnormalities in the salivary glands of patients with primary Sjögren's syndrome

Objectives

To assess non-invasive imaging for detection and quantification of gland structure, inflammation and function in patients with primary Sjogren's syndrome (pSS) using PET-CT with ¹¹C-Methionine (¹¹C-MET; radiolabelled amino acid), and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG; glucose uptake marker), to assess protein synthesis and inflammation, respectively; multiparametric MRI evaluated salivary gland structural and physiological changes.

Methods

In this imaging/clinical/histology comparative study (GSK study 203818; NCT02899377) patients with pSS and age- and sex-matched healthy volunteers underwent MRI of the salivary glands and ¹¹C-MET PET-CT. Patients also underwent ¹⁸F-FDG PET-CT and labial salivary gland biopsies. Clinical and biomarker assessments were performed. Primary endpoints were semi-quantitative parameters of ¹¹C-MET and ¹⁸F-FDG uptake in submandibular and parotid salivary glands and quantitative MRI measures of structure and inflammation. Clinical and minor salivary gland histological parameter correlations were explored.

Results

Twelve patients with pSS and 13 healthy volunteers were included. Lower ¹¹C-MET uptake in parotid, submandibular and lacrimal glands, lower submandibular gland volume, higher MRI fat fraction, and lower pure diffusion in parotid and submandibular glands were observed in patients vs healthy volunteer, consistent with reduced synthetic function. Disease duration correlated positively with fat fraction and negatively with ¹¹C-MET and ¹⁸F-FDG uptake, consistent with impaired function, inflammation and fatty replacement over time. Lacrimal gland ¹¹C-MET uptake positively correlated with tear flow in patients, and parotid gland ¹⁸F-FDG uptake positively correlated with salivary gland CD20+ B-cell infiltration.

Conclusion

Molecular imaging and MRI may be useful tools to non-invasively assess loss of glandular function, increased glandular inflammation and fat accumulation in pSS.

How does scanner choice and 3D model resolution affect data accuracy?

Researchers using digital methods often collect data from 3D models at different resolutions, obtained using different scanning techniques. Although previous research has sought to understand whether scanning method and model resolution affect data accuracy, no study has systematically evaluated the sources of error associated with scanning method, data acquisition method and model resolution with the aim of providing practical recommendations about the model resolution required to yield sufficiently accurate data for specimens of given sizes. In this study, using data taken from primate specimens of three broad size categories, we test whether 3D models obtained using five different scanners (Breuckmann SmartSCAN, DAVID/HP 3D Pro S3, NextEngine 2020i, Creaform Go!Scan 20 and microCT/clinicalCT) yield accurate measurements. We assess whether caliper measurements can be used alongside measurements collected from 3D surface models, whether scanning resolution affects measurement accuracy, and how scan resolution, estimated using each scanner's proprietary software, compares to model resolution measured in a standardized way. Each scanner produces 3D models that yield accurate measurements for each size category, however, combining caliper data with those taken from digital models can be problematic. Our results indicate that the accuracy of measurements taken from 3D models depends on both object size and model resolution. Based on our findings, we recommend that small specimens should be scanned at <0.3 mm, medium specimens at 0.3-0.7 mm, and large specimens at 0.3-0.5 mm resolutions if data taken from 3D surface models are to be combined with caliper datasets. We further show, for the first time, that discrepancies in estimated final model resolution are frequently observed across software packages. We therefore recommend that researchers ensure that final model resolutions are adequate based on specimen size and are independently verified using a software package other than the scanner's proprietary software. Finally, we consider the implications of the findings that measurements obtained from surface models are variably consistent with those obtained using calipers.

The relationship between carotid and coronary calcification in patients with coronary artery disease

BACKGROUND

Atherosclerosis is a multi-system pathology with heterogeneous involvement. We aimed to investigate the relationship between the presence and severity of carotid and coronary calcification in a group of patients with coronary artery disease.

METHODS

Sixty-three patients presenting with unstable angina or positive stress test for myocardial ischaemia were enrolled in this study. All patients underwent CT scanning of the carotid and coronary arteries using the conventional protocol and Agatston scoring system. Risk factors for atherosclerosis were also analyzed for correlation with the extent of arterial calcification.

RESULTS

Total coronary artery calcium score (CAC) was several times higher than total carotid calcium score (1274 (1018) vs 6 (124), p = 0·0001, respectively). The left carotid calcium score correlated strongly with the right carotid calcium score (rho = 0·69, p < 0·0001). The total CAC score correlated modestly with the total carotid calcium score (rho = 0·34, p = 0·007), in particular with left carotid score (rho = 0·38, p = 0·002), but not with the right carotid score. The left coronary calcium score correlated with the right coronary calcium score (rho = 0·35, p = 0·004), left carotid calcium score (rho = 0·33, p = 0·007) and left carotid calcium score at the bifurcation (rho = 0·34, p = 0·006). While hypertension correlated with carotid calcium score, diabetes and dyslipidaemia correlated with left CAC score.

CONCLUSION

In patients with coronary disease, the carotid calcification pattern appeared to be similar between the right and left system in contrast to that of the coronary arteries. CAC correlated only modestly with the carotid score, despite being significantly higher. Hypertension was related to carotid calcium score while diabetes and dyslipidaemia correlated with coronary calcification.

Fluid-Fluid Interfacial Effects in Multiphase Flow during Carbonated Waterflooding in Sandstone: Application of X-ray Microcomputed Tomography and Molecular Dynamics

Fluid-fluid interfacial reactions in porous materials are pertinent to many engineering applications such as fuel cells, catalyst design, subsurface energy recovery (enhanced oil recovery), and CO₂ storage. They have been identified to control physicochemical properties such as interfacial rheology, multiphase flow, and reaction kinetics. In recent years, engineered waterflooding has been identified as an effective way to increase hydrocarbon recovery and solid-fluid interaction has been assessed as the key mechanism. However, in this study, we demonstrated that in the absence of solid-fluid interactions (in strong hydrophilic porous media), fluid-fluid interfacial reactions can significantly affect multiphase flow and thus lead to an increased hydrocarbon recovery during engineered carbonated waterflooding. We designed a microwaterflooding system to evaluate the interfacial reactions during two phase flow with engineered carbonated waters. Given that salinity controls the amount of dissolved CO₂, we injected carbonated high salinity water and carbonated low salinity water to achieve different fluid-fluid reactions. We injected the carbonated water in a sandstone with 99.5% quartz under X-ray microcomputed tomography (μCT) scanning at a resolution of 3.43 μm per pixel. Image processing shows that carbonated low salinity waterflooding can recover 8% more oil than carbonated high salinity waterflooding, while the quartz-rich sandstone remains strongly hydrophilic in both samples. A gradual CT intensity distribution indicates an interfacial phase generation between carbonated brine and crude oil during carbonated waterflooding. Therefore, we attributed the additional hydrocarbon recoveries to the fluid-fluid interfacial reactions. To understand the effects of fluid-fluid reactions on interfacial properties, we performed molecular dynamics simulations to investigate the chemical species distribution at the interface, interfacial tension (IFT) changes, and CO₂ diffusion. The MD simulation results revealed a layered structure of the interface, a lower CO₂ diffusion coefficient in carbonated high salinity water, a lower IFT in carbonated low salinity water, a swelling hydrocarbon phase in carbonated low salinity water, and more CO₂ accumulated at the interface between the hydrocarbon phase and carbonated low salinity water. This work provides a general and fundamental understanding of the influence of fluid-fluid interactions on the interfacial properties between carbonated water and the hydrocarbon interface.

Prognostic factors of pulmonary hypertension associated with connective tissue disease: pulmonary artery size measured by chest CT

OBJECTIVE

Pulmonary artery enlargement is a common manifestation of chest CT in patients with pulmonary arterial hypertension (PAH). The exact clinical significance of this phenomenon has not been clarified in connective tissue disease (CTD)-associated PAH (CTD-PAH). We aimed to explore the association between the dilatation of pulmonary artery and prognosis of CTD-PAH patients.

METHODS

We retrospectively investigated 140 CTD-PAH patients diagnosed by echocardiography from 2009 to 2018. A chest multi-slice CT was performed on all the patients. Main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), ascending aorta (AAo) and descending aorta (DAo) diameters were measured. The ratios MPA/AAo and MPA/DAo were also calculated. The primary end point was all-cause mortality.

RESULTS

During the observational period of 3.44 (0.23) years, 36 patients were followed to death. Cox univariate proportional hazard analysis showed that age, gender, MPA diameter, LPA diameter and RPA diameter were related to the risk of 5-year all-cause mortality in patients with CTD-PAH. In Cox multivariate proportional hazard analysis, MPA diameter and gender were predictors of all-cause mortality in CTD-PAH patients. An all-cause mortality risk prediction model revealed that baseline MPA diameter has the ability to predict 5-year all-cause mortality in CTD-PAH patients. Kaplan-Meier analysis showed that the 5-year survival rate was significantly lower in patients with MPA ≥37.70 mm (P ≤ 0.00012) compared with MPA ≤ 37.70 mm.

CONCLUSION

MPA diameter ≥37.70 mm measured by chest multi-slice CT was a potential independent risk factor of the poor long-term prognosis in Chinese CTD-PAH patients.

Three-dimensional surface scanning methods in osteology: A topographical and geometric morphometric comparison

Objectives

Three‐dimensional (3D) data collected by structured light scanners, photogrammetry, and computed tomography (CT) scans are increasingly combined in joint analyses, even though the scanning techniques and reconstruction software differ considerably. The aim of the present study was to compare the quality and accuracy of surface models and landmark data obtained from modern clinical CT scanning, 3D structured light scanner, photogrammetry, and MicroScribe digitizer.

Material and methods

We tested 13 different photogrammetric software tools and compared surface models obtained by different methods for four articulated human pelves in a topographical analysis. We also measured a set of 219 landmarks and semilandmarks twice on every surface as well as directly on the dry bones with a MicroScribe digitizer.

Results

Only one photogrammetric software package yielded surface models of the complete pelves that could be used for further analysis. Despite the complex pelvic anatomy, all three methods (CT scanning, 3D structured light scanning, photogrammetry) yielded similar surface representations with average deviations among the surface models between 100 and 200 μm. A geometric morphometric analysis of the measured landmarks showed that the different scanning methods yielded similar shape variables, but data acquisition via MicroScribe digitizer was most prone to error.

Discussion

We demonstrated that three‐dimensional models obtained by different methods can be combined in a single analysis. Photogrammetry proved to be a cheap, quick, and accurate method to generate 3D surface models at useful resolutions, but photogrammetry software packages differ enormously in quality.

Value of FEops HEARTguide patient-specific computational simulations in the planning of left atrial appendage closure with the Amplatzer Amulet closure device: rationale and design of the PREDICT-LAA study

BACKGROUND

Optimal preprocedural planning is essential to ensure successful device closure of the left atrial appendage (LAA).

DESIGN

The PREDICT-LAA study is a prospective, international, multicentre, randomised controlled trial (ClinicalTrials.gov NCT04180605). Two hundred patients eligible for LAA closure with an Amplatzer Amulet device (Abbott, USA) will be enrolled in the study. Patients will be allocated to a computational simulation arm (experimental) or standard treatment arm (control) using a 1:1 randomisation. For patients randomised to the computational simulation arm, preprocedural planning will be based on the analysis of cardiac computed tomography (CCT)-based patient-specific computational simulations (FEops HEARTguide, Ghent, Belgium) in order to predict optimal device size and position. For patients in the control arm, preprocedural planning will be based on local practice including CCT analysis. The LAA closure procedure and postprocedural antithrombotic therapy will follow local practice in both arms. The primary endpoint of the study is incomplete LAA closure and device-related thrombus as assessed at 3 months postprocedural CCT. Secondary endpoints encompass procedural efficiency (number of devices used, number of repositioning, procedural time, radiation exposure, contrast dye), procedure-related complications within 7 days postprocedure and a composite of all-cause death and thromboembolic events at 12 months.

CONCLUSION

The objective of the PREDICT-LAA study is to test the hypothesis that a preprocedural planning for LAA closure with the Amplatzer Amulet device based on patient-specific computational simulations can result in a more efficient procedure, optimised procedural outcomes and better clinical outcomes as compared with a standard preprocedural planning.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04180605).

Clinical impact of CT coronary angiography without exclusion of small coronary artery segments: a real-world and long-term study

OBJECTIVES

CT coronary angiography (CTCA) has become a valuable diagnostic test in the workup of patients with possible coronary artery disease (CAD). Because of inherent limitations in spatial resolution, epicardial vessels with a small diameter, in general less than 1.5-2 mm, have so far been excluded in studies assessing clinical utility of CTCA. This study sought to assess the clinical impact of CTCA taking into account pathology in small coronary arteries.

METHODS

We conducted a retrospective cohort study of all patients with possible CAD who underwent dual-source CTCA and subsequent invasive coronary angiography (ICA) between January 2010 and July 2017. Patients with an Agatston calcium score ≥1000 were reported separately. Diagnostic accuracy of CTCA on a patient, vessel and segment level was calculated. The physician's therapeutic decision was defined as conservative, medical antianginal treatment or revascularisation. Using ICA as the reference, we calculated the precision of CTCA to replicate these therapeutic recommendations.

RESULTS

In total, 1209 patients underwent both CTCA and ICA. Overall diagnostic performance of CTCA showed a sensitivity of 90% (95% CI 86% to 93%) and specificity of 40% (95% CI 36% to 45%). With regard to clinical decision making, CTCA showed good performance: 91% of patients who were treated medically or by revascularisation were correctly identified. Prevalence of disease in small vessel segments was low: 16% showed significant CAD on ICA. Prevalence of significant disease was 70% in patients with an Agatston score ≥1000: the majority underwent revascularisation.

CONCLUSIONS

From a true patient perspective, without exclusion of smaller coronary artery segments, CTCA allows safe patient management.

Non-destructive CT Method for Spatially Resolved Measurement of Elemental Content and Density of Li-B Alloys

Lithium-boron (Li-B) alloys play an important role in the fields of thermal batteries and Li metal batteries, where the electrochemical performance is highly dependent on microstructure homogeneity and the Li content. In this study, computed tomography (CT) scanning has been firstly used to study the elemental content and spatial distribution of Li in a Li-B alloy. For a commercial Li-B alloy, quantitative relationships between the CT values, [Hu], and the weight percent of Li, w_T−Li, and the density, ρ_Li−B, that is, [Hu] =13563.836.2×wT-Li-2.8-1,016.2 and [Hu] = 790.1 × ρ_Li−B − 1, 016.2, respectively. The experimental data were found to be in good agreement with current theory. The CT scanning method was non-destructive, and proved to be fast, highly accurate, and low-cost for the characterization of Li-B alloy ingots in terms of elemental composition, density, and uniformity.

Research priorities in cardiovascular imaging

Aim

A modified Delphi approach was used to develop consensus opinion among British Society for Cardiac Imaging/British Society of Cardiac CT (BSCI/BSCCT) members in order to prioritise research questions in cardiovascular imaging.

Methods

All members of the BSCI/BSCCT were invited to submit research questions that they considered to be of the highest clinical and/or academic priority in the field of cardiovascular imaging (phase 1). Subsequently a steering committee removed duplicate questions and combined questions of a similar theme by consensus agreement where appropriate. BSCI/BSCCT members were invited to rank the resulting research questions in two further iterative rounds (phases 2 and 3) to determine a final list of high-priority research questions.

Results

A total of 111 research questions were submitted in phase 1 by 30 BSCI/BSCCT members. While there was a broad range of topics, from determining the optimal features/markers of the vulnerable plaque to investigating how cardiac imaging can best be used to maximise clinical outcomes and economic costs, multimodality imaging-related (n=44, 40%) questions dominated the categories and coronary artery imaging (n=40, 36%) was the most common topic. Over two iterative rounds of prioritisation of these research questions, the original 111 were reduced to 75 questions in round 2, and 25 in round 3. From these 25 a final Top 10 list was distilled by consensus grouping.

Conclusion

This study has identified and ranked the top research priorities in cardiovascular imaging, as identified by the BSCI/BSCCT membership. This is a first step towards identifying the cardiovascular imaging research priorities within the UK and may assist researchers and funding bodies alike in setting priorities.

Angiographic control versus ischaemia-driven management of patients undergoing percutaneous revascularisation of the unprotected left main coronary artery with second-generation drug-eluting stents: rationale and design of the PULSE trial

BACKGROUND

The role of planned angiographic control (PAC) over a conservative management driven by symptoms and ischaemia following percutaneous coronary intervention (PCI) of the unprotected left main (ULM) with second-generation drug-eluting stents remains controversial. PAC may timely detect intrastent restenosis, but it is still unclear if this translated into improved prognosis.

METHODS AND ANALYSIS

PULSE is a prospective, multicentre, open-label, randomised controlled trial. Consecutive patients treated with PCI on ULM will be included, and after the index revascularisation patients will be randomised to PAC strategy performed with CT coronary after 6 months versus a conservative symptoms and ischaemia-driven follow-up management. Follow-up will be for at least 18 months from randomisation. Major adverse cardiovascular events at 18 months (a composite endpoint including death, cardiovascular death, myocardial infarction (MI) (excluding periprocedural MI), unstable angina, stent thrombosis) will be the primary efficacy outcome. Secondary outcomes will include any unplanned target lesion revascularisation (TLR) and TLR driven by PAC. Safety endpoints embrace worsening of renal failure and bleeding events. A sample size of 550 patients (275 per group) is required to have a 80% chance of detecting, as significant at the 5% level, a 7.5% relative reduction in the primary outcome.

TRIAL REGISTRATION NUMBER

NCT04144881.

Non-invasive Diagnostic Strategy in ACTH-dependent Cushing's Syndrome

CONTEXT

Inferior petrosal sinus sampling (IPSS) is used to diagnose Cushing's disease (CD) when dexamethasone-suppression and CRH tests, and pituitary magnetic resonance imaging (MRI), are negative or give discordant results. However, IPSS is an invasive procedure and its availability is limited.

OBJECTIVE

To test a noninvasive diagnostic strategy associated with 100% positive predictive value (PPV) for CD.

DESIGN

Retrospective study.

SETTING

Two university hospitals.

PATIENTS

A total of 167 patients with CD and 27 patients with ectopic ACTH-syndrome investigated between 2001 and 2016.

MAIN OUTCOME MEASURE(S)

Performance of a strategy involving the CRH and desmopressin tests with pituitary MRI followed by thin-slice whole-body computed tomography (CT) scan in patients with inconclusive results.

RESULTS

Using thresholds of a cortisol increase > 17% with an ACTH increase > 37% during the CRH test and a cortisol increase > 18% with an ACTH increase > 33% during the desmopressin test, the combination of both tests gave 73% sensitivity and 98% PPV of CD. The sensitivity and PPV for pituitary MRI were 71% and 99%, respectively. CT scan identified 67% EAS at presentation with no false-positives. The PPV for CD was 100% in patients with positive responses to both tests, with negative pituitary MRI and CT scan. The Negative Predictive Value was 100% in patients with negative responses to both tests, with negative pituitary MRI and positive CT scan. Using this strategy, IPPS could have been avoided in 47% of patients in whom it is currently recommended.

CONCLUSIONS

In conjunction with expert radiologic interpretation, the non-invasive algorithm studied significantly reduces the need for IPSS in the investigation of ACTH-dependent Cushing's syndrome.

Derivation of an angiographically based classification system in Takayasu's arteritis: an observational study from India and North America

OBJECTIVES

To develop and replicate, using data-driven methods, a novel classification system in Takayasu's arteritis based on distribution of arterial lesions.

METHODS

Patients were included from four international cohorts at major academic centres: India (Christian Medical College Vellore); North America (National Institutes of Health, Vasculitis Clinical Research Consortium and Cleveland Clinic Foundation). All patients underwent whole-body angiography of the aorta and branch vessels, with categorization of arterial damage (stenosis, occlusion or aneurysm) in 13 territories. K-means cluster analysis was performed to identify subgroups of patients based on pattern of angiographic involvement. Cluster groups were identified in the Indian cohort and independently replicated in the North American cohorts.

RESULTS

A total of 806 patients with Takayasu's arteritis from India (n = 581) and North America (n = 225) were included. Three distinct clusters defined by arterial damage were identified in the Indian cohort and replicated in each of the North American cohorts. Patients in cluster one had significantly more disease in the abdominal aorta, renal and mesenteric arteries (P < 0.01). Patients in cluster two had significantly more bilateral disease in the carotid and subclavian arteries (P < 0.01). Compared with clusters one and two, patients in cluster three had asymmetric disease with fewer involved territories (P < 0.01). Demographics, clinical symptoms and clinical outcomes differed by cluster.

CONCLUSION

This large study in Takayasu's arteritis identified and replicated three novel subsets of patients based on patterns of arterial damage. Angiographic-based disease classification requires validation by demonstrating potential aetiological or prognostic implications.