CT Measurements Research Articles

Preoperative CT measurements for predicting postoperative complications following Whipple procedure

Preoperative CT measurements for predicting postoperative complications following Whipple procedure

Evaluating synchrophasor-enabled angle-based differential protection in distribution networks

The inclusion of Distributed Energy Resources (DERs) affects the protection requirements and the functional constraints of the modern distribution networks (MDNs). With continued research on the primary protection of MDNs, this paper evaluates an angle-based differential protection scheme utilizing synchrophasors from distribution-level phasor measurement units (D-PMUs). The suggested scheme is based on computing the Absolute Superimposed Differential Angle (ASDA) of positive sequence current between two ends of a distribution line. The ASDA concept is explained by considering internal and external fault conditions. The initial investigations are performed on a modified real-distribution network in the Dubai utility, assuming rotating or non-rotating DER. Thereafter, the scheme is thoroughly examined in a seven-node MDN modelled in Real-Time Simulator, exploring various scenarios such as different fault types, fault resistance and line length variations, switching transients, varying DER penetration levels and types, and different network operation modes. Additionally, the analysis of CT saturation effect, measurement noise and response time of the proposed scheme has been carried out. A real-time laboratory testbed is also developed utilizing physical PMUs and a real-time simulator to verify the performance of suggested scheme in a practical environment. Furthermore, a quantitative and qualitative evaluation of the proposed strategy is presented to demonstrate the strategy’s reliability and efficacy. Our findings demonstrate that the suggested approach reliably detects short-circuit faults in a broad spectrum of network conditions.

The value of volume measurement in CT in the follow-up of Stanford B aortic dissection after TEVAR

BackgroundTo investigate the value of dual-source CT combined with volumetric measurement in the follow-up of Stanford Type B aortic dissection (TBAD) intrathoracic aortic repair (TEVAR).Methods40 TBAD patients in our hospital were treated with TEVAR and followed up at 3, 6 and 12 months after surgery. Dual-source CT and volumetric measurements were used to calculate the diameters and areas of the true and false lumen and the total lumen of the left subclavian artery at a distance of 2 cm (P1), the middle part of the descending aorta (P2), the opening of the abdominal trunk (P3) and the anterior bifurcation of the abdominal aorta (P4) before and after surgery. The maximum diameter, maximum area, volume and modified aortic remodeling index (MARI) of the true and false lumen of the distal abdominal aortic dissection were measured to evaluate the postoperative vascular remodeling.ResultsThe true cavity diameter of P1 and P2 increased gradually, the false cavity diameter decreased gradually (P < 0.05), and the total and true cavity diameter of P3 and P4 increased (P < 0.05). After operation, the true cavity area of P1 and P2 gradually increased, and the false cavity area decreased (P < 0.05). The total area of P3, P4, and true cavity increased gradually after operation (P < 0.05). There were statistically significant differences in true and false lumen volume and MARI before and after surgery (P < 0.05).ConclusionCompared with diameter measurement and area measurement, volume measurement can more accurately reflect the remodeling of the true and false lumen of the uncoated aortic dissection.Clinical trial numberNot applicable.

Three-Dimensional Visualization of Inhomogeneous Reaction within Individual Active Material Particles in Composite Solid-State Battery Electrodes Using Nano CT-XANES

Introduction Solid-state batteries (SSBs) are next-generation batteries that are expected to exhibit higher energy density, power density, and safety than current lithium-ion batteries. In composite SSB electrodes, randomly distributed particles of active material (AM) and solid electrolyte (SE), and voids form three-dimensionally complicated ion/electron conduction paths and AM/SE interfaces. Such complex mass transport paths and limited AM/SE interfaces can locally impede the ion/electron supply to AM particles particularly under the rapid (dis)charging, potentially leading to a three-dimensional (3D) inhomogeneous reaction within each AM particle, as well as between particles. The occurrence of such inhomogeneous reaction can severely deteriorate the capacity, power output, and cycle life of SSBs. Therefore, it is essential to understand the mechanism of the occurrence of the inhomogeneous reaction and to design electrodes that enable uniform reaction progression. The most effective approach for this is the direct observation of the 3D inhomogeneous reaction within individual AM particles in actual composite SSB electrodes. However, most of existing methods enables only one- or two-dimensional observation of the inhomogeneous reaction1, 2, offering limited insight into the 3D reaction inhomogeneity in AM particles in SSB electrodes. With this background, in this work, we developed a 3D visualization technique of inhomogeneous reaction within individual AM particles in a composite SSB electrode using X-ray nano computed tomography technique combined with X-ray absorption near-edge structure spectroscopy (nano CT-XANES). Using this technique, we three-dimensionally observed the inhomogeneous reaction in each of thousands of AM particles in composite SSB electrodes. Furthermore, based on the obtained information, we discussed the optimal AM particle parameters (e.g., size, shape, particle distribution) that can alleviate the inhomogeneous reaction within and between AM particles, thereby maximizing electrode performance. Experimental The composite cathodes to be observed were prepared by mixing LiNi1/3Mn1/3Co1/3O2 (NMC) primary particle powders and Li2.2C0.8B0.2O3 (LCBO) solid electrolyte powders in a 1:1 weight ratio. The model SSBs were fabricated with the composite cathode (~50 μm thickness), LCBO solid electrolyte, poly (ethylene oxide) (PEO)-based polymer electrolyte, and Li metal anode. The model SSBs were charged to 100 mAh/g at 0.1~0.2 C, and the inhomogeneous reactions within AM particles in the composite cathodes after charging were visualized using nano CT-XANES. In the nano CT-XANES measurements, CT measurements were conducted near the Ni K-edge (8345.9-8352.4 eV) by incrementing the X-ray energy in 0.2 eV steps, with the entire set of measurements requiring approximately 25 minutes. The state-of-charge (SOC) of NMC (x in Li x Ni1/3Mn1/3Co1/3O2) in each voxel in the 3D CT images was evaluated based on the peak top energy shift of the Ni K-edge XANES spectrum in the respective voxels. Results and discussion Figures 1(a) and (b) show 3D SOC maps of the composite cathode after charging to 100 mAh/g at 0.2 C viewed from two different angles, and the corresponding charging curve, respectively. The observation area was approximately 34 × 47 μm in the in-plane direction of the electrode and approximately 34 μm thick with the voxel size of approximately 0.3 μm. The red/blue colored regions represent the charged (x = 0.45)/uncharged (x = 1.0) AM particles, respectively, while the transparent regions correspond to the SE or voids. As shown in this figure, the SOC of individual AM particles after charging varied significantly among the particles. While some particles, such as particle A, were charged to a Li content corresponding to the charging capacity of the entire electrode of 100 mAh/g (x = 0.64), there were also insufficiently charged particles (particle B) and excessively charged ones (particle C) relative to the average capacity of the entire electrode. These results indicates that the charge reactions proceeded inhomogeneously between AM particles. Furthermore, as shown in the 3D SOC maps of representative AM particles in Fig. 1(c), the reaction proceeded inhomogeneously within a particle. While the reaction progressed relatively uniformly within particles 1 and 2, the reaction proceeded quite inhomogeneously within particles 3 and 4. As described above, the charging state and its intra-particle inhomogeneity varied significantly among AM particles. To identify the characteristics of AM particles that determine the charging state and its inhomogeneity in each particle, in the presentation, we will statistically investigate the correlation between reaction states of each particle and morphological characteristics such as size and shape, for thousands of AM particles in the observation area.

Radiological features of the carpometacarpal joint in hamate body fracture on anteroposterior hand X-ray image

BackgroundHamate body fractures are rare and can be overlooked due to the diagnostic difficulty on X-ray. We focused on the carpometacarpal joint space width (CMC-JSW) and examined the features of this fracture on versatile anteroposterior hand X-ray images, initially taken for hand trauma cases. MethodsTen patients (nine males and one female; mean age, 34 years) diagnosed with a hamate body fracture on CT in our facility between January 2013 and October 2023 were included in this study. The fracture types were dorsal type in six cases and shear type in four cases. The 4th and 5th CMC-JSWs were measured on anteroposterior hand radiography and CT sagittal sections. If the metacarpal and hamate bones appeared to overlap due to depression, the width was expressed as a negative value (overlap sign). CMC-JSWs were compared between the types or unaffected sides using the Mann–Whitney U test. The correlation with X-ray and CT measurements was analyzed using the Spearman test. ResultsThe average CMC-JSWs (IV: −0.52 mm, V: −1.33 mm) in hamate body fractures on X-ray were minus and these values were significantly lower than unaffected side (IV: 1.51 mm, V: 1.48 mm) (p < 0.05, p < 0.001). CMC-JSW (IV: −1.64 mm) and CMC-JSW (V: −2.70 mm) of dorsal type were significantly lower than shear type (IV: 1.17 mm, V: 0.72 mm) (p < 0.05). CMC-JSW values on X-ray were positively correlated with those on CT (IV: ρ = 0.796, V: ρ = 0927). ConclusionsDecreased CMC-JSW, correlated with CT sagittal sections, and “overlap sign” on anteroposterior hand X-ray were possible radiological characteristics of hamate body fracture. Care should be taken to avoid overlooking shear-type fractures because of subtle CMC-JSW decreases.

Mono-pole blocking accident analysis caused by inaccurate measurement of optical CT in ±800 kV UHVDC transmission system under lightning strike

The ultra-high voltage direct current (UHVDC) power transmission systems usually transmit a capacity of 6-8 GW, their stability and reliability are of vital importance to the large power grid. This paper analyses a mono-pole blocking accident caused by the inaccurate measurement of optical current transformer (OCT) when the pole line of Shaanbei-Wuhan ±800 kV UHVDC transmission system was struck by lightning. Combined with electromagnetic transient simulation of the UHVDC transmission system, digital simulation and in-plant testing of the optical CT, a comprehensive understanding of the factors contributing to the accident is achieved. It reveals that optical CT measurement anomalies were significant contributors to the misoperation of protective relays, which led to the mono-pole blocking accident. Based on the simulations of optical CT under high peak currents and high di/dt conditions caused by lightning strike, the importance of proper setting of demodulation algorithm parameters in optical CT to avoid inaccurate measurements is emphasized. Through in-plant testing and steady state current accuracy verification, the reasonableness of demodulation parameters is verified. Simulation results illustrate the challenges in measuring very fast transient current accurately, which are the premise and guarantee of stable operation of UHVDC transmission systems under lightning strike.

In-Stent Restenosis in Peripheral Arterial Disease: Ultra-High-Resolution Photon-Counting Versus Third-Generation Dual-Source Energy-Integrating Detector CT Phantom Study in Seven Different Stent Types.

The visualization of peripheral in-stent restenosis using energy-integrating detector CT is challenging due to deficient spatial resolution and artifact formation. This study compares the first clinically available photon-counting detector CT to third-generation dual-source energy-integrating detector CT. Nylon cylinders with central bores (4mm, 2mm), mimicking 75% and 95% stenoses, were placed inside seven different 8-mm diameter stents and filled with diluted contrast medium. Phantoms were scanned with photon-counting detector CT at slice thicknesses of 0.2mm (available only in this scanner type), 0.5mm, and 1.0mm versus 0.5mm and 1.0mm in energy-integrating detector CT at matched CT dose indices. Contrast-to-noise ratios were calculated from attenuation rates. Residual lumen size was measured as full width at half-maximum. Subjective image quality was assessed by two independent blinded raters. Mean contrast-to-noise ratio was lowest in photon-counting detector CT at 0.2mm slice thickness (0%, 75%, and 95% in-stent restenosis: 6.11 ± 0.6, 5.27 ± 0.54, and 5.02 ± 0.66) and highest at 1.0mm slice thicknesses with similar measurements in photon-counting detector CT and energy-integrating detector CT (11.46 ± 1.08, 9.94 ± 1.01, 8.26 ± 1.0 vs. 3.34 ± 1.0, 9.92 ± 0.38, 7.94 ± 1.07). Mean full width at half-maximum measurements in photon-counting detector CT at 0.2mm slice thickness for 0%, 75%, and 95% in-stent restenosis were 8.00 ± 0.37, 3.98 ± 0.34, and 1.92 ± 0.16mm. Full width at half-maximum was least precise in 95% in-stent restenosis at 1.0mm slice thickness with similar measurements between scanners (1.57 ± 0.33 vs. 1.71 ± 0.15mm). Interrater correlation coefficient was 0.75 [95% CI: [0.53; 0.86]; subjective scores were best at 0.2mm slice thickness in photon-counting detector CT (19.43 ± 0.51 and 19.00 ± 0.68). In phantom in-stent restenosis in 8mm stents, we observed similar full width at half-maximum for photon-counting detector CT and energy-integrating detector CT in 0% and 75% in-stent restenosis, but at 95% in-stent restenosis, FWHM tended to be more accurate in smaller slice thicknesses in both scanners. Subjective image assessment yielded best results at 0.2mm slice thickness in photon-counting detector CT despite lower contrast-to-noise ratio.

Radiologists Versus AI-Based Software: Predicting Lymph Node Metastasis and Prognosis in Lung Adenocarcinoma From CT Under Various Image Display Conditions

PurposeTo compare the variability of quantitative values from lung adenocarcinoma CT images independently assessed by 2 radiologists and AI-based software under different display conditions, and to identify predictors of pathological lymph node metastasis (LNM), disease-free survival (DFS), and overall survival (OS). MethodsPreoperative CT images of 307 patients were displayed under 4 conditions: lung-1, lung-2, mediastinum-1, and mediastinum-2. Two radiologists (R1, R2) measured total diameter (tD) and the longest solid diameter (sD) under each condition. The AI-based software automatically detected lung nodules, providing tD, sD, total volume (tV), and solid volume (sV). ResultsAll measurements by R1 and R2 with AI-based software were identical. Four out of the 8 measurements showed significant variation between R1 and R2. For LNM, multivariate logistic regression identified significant indicators including sD at mediastinum-2 of R1, sD at mediastinum-1 and mediastinum-2 of R2, tV, and the proportion of sV to tV (sV/tV) of AI-based software. For DFS, multivariate Cox regression identified sD at lung-1 of R1, the proportions of sD to tD at lung-2 of R1, sD at lung-2 and mediastinum-1 of R2, tV, and sV/tV of AI-based software as significant. For OS, multivariate Cox regression identified sD at lung-1 and mediastinum-2 of R1, tD at lung-2 of R2, sD at mediastinum-1 of R2, sV, and sV/tV of AI-based software as significant. ConclusionRadiologists’ CT measurements were significant predictors of LNM and prognosis, but variability existed among radiologists and display conditions. AI-based software can provide accurate and reproducible indicators for predicting LNM and prognosis.

Aortic valve tissue quantification in bicuspid aortic valve stenosis

Abstract Background The relative contribution of calcific versus noncalcific aortic valve tissue volume to aortic stenosis (AS) in bicuspid aortic valve (BAV) is unclear. Purpose We aimed to assess the association of aortic valve tissue volume quantified by contrast-enhanced CT with echocardiographic AS severity, and diagnostic implication of noncalcific tissue volume for severe AS. Methods We retrospectively identified 234 patients with BAV who had echocardiographic AS severity and contrast-enhanced CT evaluation within six months and left ventricular ejection ≥50%, including 150 severe AS (aortic valve area≤1 cm2 or indexed valve area≤0.6cm2/m2 plus mean grdient≥40mmHg or peak velocity≥4 m/s), 84 nonsevere AS (61 with at least mild AS: peak veloicty≥2.0 m/s plus mean gradient ≥10mmHg, and 23 with normal aortic valve function). Contrast-enhanced CT aortic valve calcific volume and noncalcific (fibrosis) volume were quantified using patient-specific Hounsfield unit thresholds (Figure). Noncontrast CT aortic valve calcium score (AVCscore) was quantified by the Agaston method. CT measurements were indexed to echocardiographic aortic valve annulus area and square-root transformed for the analysis. Results Of 234 patients, the mean age was 64±11 years, and 64% were men. There were positive correlations of indexed calcific volume, noncalcific volume, and inverse correlations of percentages of noncalcific volume (noncalcific volume divided by the sum of calcific and noncalcific volume) with peak velocity and mean gradient (|r|=0.30 to 0.68). Among 150 patients with severe AS, 28 had an AVCscore below the severe AVC threshold (1200 AU in women and 2000 AU in men) while exhibited a higher percentage of noncalcific volume compared to 122 patients with severe AVCscore (67±15% vs. 39±15%, p&amp;lt;0.001). After excluding 122 patients with severe AS and severe AVCscore, the indexed noncalcific volume was associated with severe AS (β±S.E: 0.18±0.07, p=0.005) with an area under the curve of 0.71; in contrast, AVCscore was not (p=0.55). Conclusion Both calcific and noncalcific aortic valve tissue volume contribute to AS severity in patients with BAV. Notably, noncalcific tissue volume is a key factor in determining severe AS in patients without severe AVCscore, suggesting its potential diagnostic value.Figure

CT measurement of blood perfusion in hepatocellular carcinoma: from basic principle, measurement methods to clinical application

Hepatocellular carcinoma (HCC) is one of the common and fatal malignant tumors worldwide, and the burden of HCC is particularly severe in China. Physiologically, the blood supply to healthy liver is mainly from the portal vein, supplemented by the hepatic artery. While in the development of HCC, the main source of blood supply to HCC is changed from the portal vein to the hepatic artery. The characteristics of HCC vascularization are important for imaging, surgery, interventional therapy, targeted therapy, etc. Even in the future, with the development of radiation therapy technology, such as proton and heavy ion therapy and artificial intelligence technology, the dynamic changes in HCC blood perfusion can be used as a new biomarker of tumor activity to provide accurate information on the intensity modulation of radiotherapy, so that accurate measurements of HCC blood perfusion is of great significance in guiding the diagnosis and treatment of HCC. The technologies for measurement of HCC blood perfusion have developed from invasive techniques, such as inert gas scavenging, electromagnetic flowmeter, and radionuclide-labeled erythrocyte elution in the middle of the last century to the present non-invasive techniques of CT. With the development of CT imaging technology in the last 30 years, the CT-based imaging technology can assess the status of organ and tissue perfusion relatively easily and accurately. In this paper, the various CT measurement techniques of blood perfusion in HCC were categorized into three types: semi-quantitative technique, relative quantitative technique, and absolute quantitative technique. Their basic principle, scanning methods, and clinical applications were discussed to provide a reference for the diagnosis and treatment of HCC.

Coronary CT angiography-based FFR with ultrahigh-resolution photon-counting detector CT: Intra-individual comparison to energy-integrating detector CT

PurposeTo evaluate the feasibility of CT angiography-derived fractional flow reserve (CT-FFR) calculations on ultrahigh-resolution (UHR) photon-counting detector (PCD)-CT series and to intra-individually compare the results with energy-integrating (EID)-CT measurements. MethodProspective patients with calcified plaques detected on EID-CT between April 1st, 2023 and January 31st, 2024 were recruited for a UHR CCTA on PCD-CT within 30 days. PCD-CT was performed using the same or a lower CT dose index and an equivalent volume of contrast media. An on-site machine learning algorithm was used to obtain CT-FFR values on a per-vessel and per-patient basis. For all analyses, CT-FFR values ≤ 0.80 were deemed to be hemodynamically significant. ResultsA total of 34 patients (age: 67.3 ± 6.6 years, 7 women [20.6 %]) were included. Excellent inter-scanner agreement was noted for CT-FFR values in the per-vessel (ICC: 0.93 [0.90–0.95]) and per-patient (ICC: 0.94 [0.88–0.97]) analysis. PCD-CT-derived CT-FFR values proved to be higher compared to EID-CT values on both vessel (0.58 ± 0.23 vs. 0.55 ± 0.23, p < 0.001) and patient levels (0.73 ± 0.23 vs. 0.70 ± 0.22, p < 0.001). Two patients (5.9 %) with hemodynamically significant lesions on EID-CT were reclassified as non-significant on PCD-CT. All remaining participants were classified into the same category with both scanner systems. ConclusionsWhile UHR CT-FFR values demonstrate excellent agreement with EID-CT measurements, PCD-CT produces higher CT-FFR values that could contribute to a reclassification of hemodynamic significance.

Correlation of CT measurements of total body gas volume and hounsfield units with post-mortem interval

Accurate estimation of the post-mortem interval (PMI) may be a matter of crucial importance in forensic investigations.A preliminary investigation to assess whether longitudinal changes in organ Hounsfield units (HU) and total body gas volume (TBGV), as measured from serial PMCT scans, correlate with postmortem interval (PMI).: Eight euthanised lambs each had five whole body CT scans performed over seven days and measurements were taken from the brain, heart, lungs, liver, kidneys and spleen. HU tissue density was measured directly from the PMCT images, while TBGV was calculated using ImageJ software. A random effect model was fitted with the subject fitted as a random intercept. Ethical and Animal Welfare approval was obtained. : The average increase in TBGV was 422 ml/Kg with a change of 77 ml/Kg per day. For each additional post-mortem day, the HU of the brain, heart, lung, liver and spleen decreased by per day since death, while HU for the kidneys increased by day since death. Expect for the kidney where it increased, there was clear and progressive decrease in tissue densities and for all organs there was an increase in TBGV over time. However, the overlap in values between cases indicates that more work is required before either HU or TBGV can be developed as non-invasive methods to reliably determine time of death in humans.

Application of a customized 3D-printed osteotomy guide plate for tibial transverse transport

Enhance the efficiency of tibial transverse transport by employing customized 3D-printed osteotomy guide plates and striving to improve precision through CT evaluation for enhanced guide design. 17 diabetic foot patients were treated with the plate for tibial transverse transport. Preoperatively, we collected DICOM data from the affected tibia’s CT and designed the geometric parameters of the tibial cortical bone window. A customized 3D-printed osteotomy guide plate was then fabricated using 3D printing technology. Postoperative X-ray and CT evaluations, conducted at two and five weeks post-surgery, assessed five crucial geometric parameters of the bone window. Measurements included the distance from the upper edge of the tibial cortical bone window to the tibial plateau, the distance from the anterior edge of the tibial cortical bone window to the bone ridge, the height of the tibial cortical bone window, the center-to-center distance between the 4.0 mm diameter Schanz pin and the osteotomy Kirschner pin, and the center-to-center distance of the 4.0 mm diameter Schanz pin. These measured parameters were subsequently compared to the preoperative design parameters. The Clinical trial registration number is ChiCTR2400087174. CT measurements showed no significant differences (P > 0.05) from preoperative design parameters across the five evaluated aspects. The average osteotomy duration was 35 ± 15 min with no bone window fractures. The bone window aligned effectively with the tibial shaft, achieving complete incorporation after distraction. A 4 to 8-month postoperative follow-up confirmed full healing of the tibial surgical wound and diabetic foot wounds. Utilizing customized 3D-printed osteotomy guide plates in tibial transverse bone transport surgery enables accurate translation of preoperative virtual designs into real-time procedures, enhancing surgical efficiency and quality.

Relation between sarcopenia and hepatic encephalopathy in liver cirrhosis - a study in tertiary care hospital

Introduction: Liver cirrhosis is a common medical problem associated with high morbidity and mortality. Consequences of cirrhosis leading to encephalopathy is a neuropsychiatric manifestation requiring hospital admission and poor prognosis. Similarly, sarcopenia in cirrhosis, resulting from multifactorial cause confers prognostic significance. The objective of this study is to find the relation between sarcopenia and hepatic encephalopathy. Methods: A retrospective observational study was conducted and data was taken from electronic medical records of patients admitted with hepatic encephalopathy in department of gastroenterology of Tribhuvan university Teaching hospital. A total of 96 cirrhotic patients were included during one and half year study duration. Sarcopenia was assessed using assessment tool like hand grip strength, chair stand test and CT measurement of either skeletal muscle area (SMA) or skeletal muscle index (SMI). Hepatic encephalopathy was graded according to West Haven criteria among admitted patients. Results: Among 96 patients with cirrhosis, 85 patients (88.5%) were found to have sarcopenia. Prevalence of sarcopenia was higher among female compared to male (97% vs 84%). Similarly, sarcopenia was found to be higher in patients with HE-2 and HE-3 compared to HE-1 ( 91% vs 93% vs 79% respectively). Conclusion: Sarcopenia is commonly associated with hepatic encephalopathy. Bangladesh J Medicine 2024; 35: 195-199

Application research on asthma-COPD overlap using low-dose CT scan and quantitative analysis

The aim of this study was to assess the proximal airway remodeling, emphysema, and air trapping of asthma-COPD Overlap. 20 ACO patients, 55 mild to moderate COPD patients and 38 non-severe asthma patients were participated in low-dose dual phase CT scanning and pulmonary function test, comparative analysis was performed to identify differences in CT measurements among three groups. (Ⅰ) The average age and smoking index of ACO and mild to moderate COPD were both higher than non-severe asthma. ACO and mild to moderate COPD group had a higher proportion of males than non-severe asthma. (Ⅱ) In terms of pulmonary function test, FEV1 (%Pred), FEV1/FVC%, MEF25% (%Pred), MEF 50% (%Pred), MMEF (%Pred), and PEF (%Pred) in ACO were significantly reduced than those in non-severe asthma. (Ⅲ) On proximal airway parameters, ACO exhibited higher WA% and Pi10 compared to mild to moderate COPD. However, there was no statistically significant difference in WA% and Pi10 between ACO and non-severe asthma. (Ⅳ) On CT lung function, the emphysema index VI-910ex of ACO was significantly higher than non-severe asthma.Additionally, ACO demonstrated higher MLDex and VI-856ex compared to non-severe asthma. Compared with non-severe asthma, ACO is more common in male patients with older age and a longer history of smoking, which had more severe airflow obstruction and airway dysfunction than non-severe asthma.ACO showed more obvious proximal airway remodeling than mild to moderate COPD, and was more similar to non-severe asthma.The extent of emphysema and air trapping in ACO were more pronounced compared to non-severe asthma.

Cochlear Apex Triangulation Utilizing Ct Measures And Middle Ear Landmarks.

To better characterize the cochlear apex in relation to surgically relevant landmarks to guide surgeons and improve procedural success of apical electrode placement. Retrospective image analysis. Tertiary referral center. Cochlear implant recipients with available preoperative computed tomography (CT) imaging. None. Cochlear dimensions and cochlear apex distance measures to surgically relevant middle ear landmarks and critical structures. Eighty-two temporal bone CT scans were analyzed utilizing multiplanar reformats. The average lateral width of promontory bone over the cochlear apex was 1.2 mm (standard deviation [SD], 0.3). The anteroposterior distance from the round window (avg, 4.2 mm; SD, 0.5), oval window (avg, 3.3 mm; SD, 0.3), cochleariform process (avg, 2.3; SD, 0.5), and superior-inferior distance from the cochleariform process (avg, -0.9; SD, 0.8) to the cochlear apex were measured. The relationship of the cochlear apex to critical structures was highly variable.A newly developed stapes vector was created and found to mark the posterior/superior boundary of the apex in 94% of patients. When a vector parallel to the stapes vector was drawn through the round window, it marked the anterior/inferior boundary of the cochlear apex in 89% of patients. This study assists in characterizing cochlear apex anatomy and its relation to surrounding structures as a means of improving procedural accuracy and reducing trauma during apical cochleostomy. Understanding both distance relationships and expected boundaries of the apex could help to inform future surgical approaches.

Early three-dimensional growth in uncomplicated type B aortic dissection is associated with long-term outcomes

ObjectiveLate adverse events (LAEs) are common among initially uncomplicated type B aortic dissection (uTBAD); however, identifying those patients at highest risk of LAEs remains a significant challenge. Early false lumen (FL) growth has been suggested to increase risk, but confident determination of growth is often hampered by error in two-dimensional clinical measurements. Semi-automated three-dimensional (3D) mapping of aortic growth, such as by vascular deformation mapping (VDM), can potentially overcome this limitation using computed tomography angiograms (CTA). We hypothesized that FL growth in the early pre-dissection phase by VDM can accurately predict LAEs. MethodsWe performed a two-center retrospective study of patients with uTBAD, with paired CTAs in the acute (1-14 days) and subacute/early chronic (1-6 months) periods. VDM analysis was used to map 3D growth. Standard clinical CT measures (ie, aortic diameters, tear characteristics) were also collected. Multivariate analysis was conducted using a decision tree and Cox proportional hazards model. LAEs were defined as aneurysmal FL (>55 mm); rapid growth (>5 mm within 6 months); aorta-specific mortality, rupture, or re-dissection. ResultsA total of 107 (69% male) patients with uTBAD initially met inclusion criteria with a median follow-up of 7.3 years (interquartile range [IQR], 4.7-9.9 years). LAEs occurred in 72 patients (67%) at 2.5 years (IQR, 0.7-4.8 years) after the initial event. A multivariate decision tree model identified VDM growth (>2.1 mm) and baseline diameter (>42.7 mm) as optimal predictors of LAEs (area under the receiver operating characteristic curve = 0.94), achieving an 87% accuracy (sensitivity of 93%, specificity of 76%) after leave-one-out validation. Guideline reported high-risk features were not significantly different between groups. ConclusionsEarly growth of the FL in uTBAD was the best tested indicator for LAEs and improves upon the current gold-standard of baseline diameter in selecting patients for early prophylactic thoracic endovascular aortic repair.

Differences in muscle composition and functionality: Exploring CT anatomical points and SARC-F components

PurposeOur study aimed to 1) investigate the differences of muscle parameters in relation to each SARC-F component/question; and 2) explore the relationship between SARC-F score with these muscle parameters using various landmarks derived from computed tomography (CT) scans of patients with cancer. MethodsThis study is a cross-sectional analysis of a cohort comprised of consecutive patients with cancer, displaying CT scans. SARC-F questionnaire was utilized as a proxy for muscle functionality, with a score ≥4 indicating a poor status. Muscle assessment via CT measurements was performed using single cross-sectional images at the level of the third lumbar vertebrae (L3) in the abdominal region, the thigh region, and the total gluteal region at the level of the second sacral vertebrae. Skeletal muscle (SM) cross-sectional area, SM index (normalized to height2), and SM radiodensity (SMD) were evaluated for all anatomical landmarks. ResultsA total of 128 patients were included in this analysis (53.1% females, 61.7% older adults). Patients with SARC-F scores ≥4 demonstrated significantly lower values of SMD across all landmarks assessed. Those reporting difficulties related to strength (P = 0.039), requiring assistance in walking (P = 0.033), and climbing stairs (P = 0.012) exhibited significantly lower SMD values at the L3 landmark. At gluteus and thigh levels, only patients experiencing difficulty climbing stairs (P = 0.012) showed significantly lower values of SMD. Only SMD at gluteus level was independently associated with SARC-F score (βadjusted –0.09, 95% CI –0.16 to –0.02). ConclusionsOur findings suggest that individuals with poor muscle composition may experience a higher risk of sarcopenia/poor muscle functionality.

Deep learning-based pseudo-CT synthesis from zero echo time MR sequences of the pelvis

ObjectivesTo generate pseudo-CT (pCT) images of the pelvis from zero echo time (ZTE) MR sequences and compare them to conventional CT.MethodsNinety-one patients were prospectively scanned with CT and MRI including ZTE sequences of the pelvis. Eleven ZTE image volumes were excluded due to implants and severe B1 field inhomogeneity. Out of the 80 data sets, 60 were used to train and update a deep learning (DL) model for pCT image synthesis from ZTE sequences while the remaining 20 cases were selected as an evaluation cohort. CT and pCT images were assessed qualitatively and quantitatively by two readers.ResultsMean pCT ratings of qualitative parameters were good to perfect (2–3 on a 4-point scale). Overall intermodality agreement between CT and pCT was good (ICC = 0.88 (95% CI: 0.85–0.90); p < 0.001) with excellent interreader agreements for pCT (ICC = 0.91 (95% CI: 0.88–0.93); p < 0.001). Most geometrical measurements did not show any significant difference between CT and pCT measurements (p > 0.05) with the exception of transverse pelvic diameter measurements and lateral center-edge angle measurements (p = 0.001 and p = 0.002, respectively). Image quality and tissue differentiation in CT and pCT were similar without significant differences between CT and pCT CNRs (all p > 0.05).ConclusionsUsing a DL-based algorithm, it is possible to synthesize pCT images of the pelvis from ZTE sequences. The pCT images showed high bone depiction quality and accurate geometrical measurements compared to conventional CT.Critical relevance statementpCT images generated from MR sequences allow for high accuracy in evaluating bone without the need for radiation exposure. Radiological applications are broad and include assessment of inflammatory and degenerative bone disease or preoperative planning studies.Key PointspCT, based on DL-reconstructed ZTE MR images, may be comparable with true CT images.Overall, the intermodality agreement between CT and pCT was good with excellent interreader agreements for pCT.Geometrical measurements and tissue differentiation were similar in CT and pCT images.Graphical

Operando X-Ray CT Analysis of Silicon/Solid Electrolyte Mechanical Interface of All-Solid-State Battery during Charging and Discharging Reaction

Silicon has a theoretical capacity about 10 times that of graphite, so it is expected to be one of the next-generation anode materials to further increase the capacity of batteries. However, silicon has a large volume change during charging and discharging, which result in poor cyclability. Although morphological change of silicon has been shown in a lot of previous studies, most of them are ex-situ observations using electron microscopes such as SEM and are two-dimensional observations1). Moreover, many previous studies target liquid battery. It is necessary to understand the expansion and shrinkage mechanism of silicon to improve all-solid-state battery performance using silicon anode. Synchrotron X-ray computed tomography (X-ray CT) is a technique that can measure the internal structure of a battery in three dimensions with micrometer-order spatial resolution in a short time. In addition, operando X-ray CT measurement is possible under charging and discharging in an all-solid-state battery2). In this study, we analyzed that morphological changes of silicon during charging and discharging by operando X-ray CT measurements.We used LiNi1/3Co1/3Mn1/3O2 (NCM), Li6PS5Cl (LPSCl) and acetylene black (AB), which were mortar-mixed in a mass ratio of 1:1:0.1 as the cathode composite material, and Si, LPSCl and AB in a mass ratio of 1:2.78:0.42 as anode composite material. Si｜LPSCl｜NCM all-solid-state cells were assembled. X-ray CT measurements at SPring-8 BL20XU using 20 keV X-rays while performing constant current charge/discharge measurement at 2.3×10-3 A cm-2. The pixel resolution was 0.5 µm. A silicon particle was extracted from the X-ray CT images obtained from X-ray CT measurements to observe the morphological changes of silicon during charging and discharging reaction. Then, change of the silicon volume and the contact area fraction of silicon particle and LPSCl solid electrolyte were calculated.Volume expansion was observed with lithiation of silicon and volume shrinkage with delithiation of silicon. As the lithiation process, silicon density decreased, and silicon was observed to be darker. As the delithiation process, cracks appeared in the silicon particle as the expanded silicon shrank. In addition, the silicon/solid electrolyte interface changed so that the silicon formed shell voids at the surface of silicon particles. This indicates that the plasticity of the LPSCl solid electrolyte cannot follow the form change of the interface. However, shell voids in the interface were formed for all directions, but some parts remained in contact area between the silicon particle and the solid electrolyte. After the second cycle of lithiation, cracks in the particle and the voids in the interface between the silicon particle and the solid electrolyte that had been formed due to the shrinkage of silicon as the delithiation disappeared by the re-lithiation. However, the re-delithiation caused cracks in the particle in the same area and formed shell voids in the interface again. Moreover, as the second delithiation process, the number of cracks in the particle increased compared with that as the first delithiation. This suggests that the number of cracks in the particle increases as silicon repeated lithiation and delithiation, and so silicon is miniaturized. In addition, a correlation was confirmed between the silicon volume change and the contact area fraction change. After the first cycle, the volume didn’t return to pristine silicon volume and the contact area fraction was reduced compared to pristine silicon. The isolation of the silicon particle from the solid electrolyte interface is suggested to be one of the factors causing the poor cycle performance because of the lithium ion reaction path is limited.1) T. Li, J. Y. Yang, S.G. Lu, H. Wang and H. Y. Ding, Rare Metals, 32, 299-304 (2013).2) Y. Sakka, H. Yamashige, A. Watanabe, A. Takeuchi, M. Uesugi, K. Uesugi and Y. Orikasa, J. Mater. Chem. A, 10, 16602–16609 (2022).