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European Radiology Experimental Jul 2024Computed tomography (CT) is the usual modality for diagnosing stroke, but conventional CT angiography reconstructions have limitations.
BACKGROUND
Computed tomography (CT) is the usual modality for diagnosing stroke, but conventional CT angiography reconstructions have limitations.
METHODS
A phantom with tubes of known diameters and wall thickness was scanned for wall detectability, wall thickness, and contrast-to-noise ratio (CNR) on conventional and spectral black-blood (SBB) images. The clinical study included 34 stroke patients. Diagnostic certainty and conspicuity of normal/abnormal intracranial vessels using SBB were compared to conventional. Sensitivity/specificity/accuracy of SBB and conventional were compared for plaque detectability. CNR of the wall/lumen and quantitative comparison of remodeling index, plaque burden, and eccentricity were obtained for SBB imaging and high-resolution magnetic resonance imaging (hrMRI).
RESULTS
The phantom study showed improved detectability of tube walls using SBB (108/108, 100% versus conventional 81/108, 75%, p < 0.001). CNRs were 75.9 ± 62.6 (mean ± standard deviation) for wall/lumen and 22.0 ± 17.1 for wall/water using SBB and 26.4 ± 15.3 and 101.6 ± 62.5 using conventional. Clinical study demonstrated (i) improved certainty and conspicuity of the vessels using SBB versus conventional (certainty, median score 3 versus 0; conspicuity, median score 3 versus 1 (p < 0.001)), (ii) improved sensitivity/specificity/accuracy of plaque (≥ 1.0 mm) detectability (0.944/0.981/0.962 versus 0.239/0.743/0.495) (p < 0.001), (iii) higher wall/lumen CNR of SBB of (78.3 ± 50.4/79.3 ± 96.7) versus hrMRI (18.9 ± 8.4/24.1 ± 14.1) (p < 0.001), and (iv) excellent reproducibility of remodeling index, plaque burden, and eccentricity using SBB versus hrMRI (intraclass correlation coefficient 0.85-0.94).
CONCLUSIONS
SBB can enhance the detectability of intracranial plaques with an accuracy similar to that of hrMRI.
RELEVANCE STATEMENT
This new spectral black-blood technique for the detection and characterization of intracranial vessel atherosclerotic disease could be a time-saving and cost-effective diagnostic step for clinical stroke patients. It may also facilitate prevention strategies for atherosclerosis.
KEY POINTS
• Blooming artifacts can blur vessel wall morphology on conventional CT angiography. • Spectral black-blood (SBB) images are generated from material decomposition from spectral CT. • SBB images reduce blooming artifacts and noise and accurately detect small plaques.
Topics: Humans; Phantoms, Imaging; Male; Female; Middle Aged; Intracranial Arteriosclerosis; Aged; Computed Tomography Angiography; Sensitivity and Specificity; Stroke; Tomography, X-Ray Computed
PubMed: 38955951
DOI: 10.1186/s41747-024-00473-x -
Annals of Biomedical Engineering Jul 2024In dynamic impact events, thoracic injuries often involve rib fractures, which are closely related to injury severity. Previous studies have investigated the behavior of...
In dynamic impact events, thoracic injuries often involve rib fractures, which are closely related to injury severity. Previous studies have investigated the behavior of isolated ribs under impact loading conditions, but often neglected the variability in anatomical shape and tissue material properties. In this study, we used probabilistic finite element analysis and statistical shape modeling to investigate the effect of population-wide variability in rib cortical bone tissue mechanical properties and rib shape on the biomechanical response of the rib to impact loading. Using the probabilistic finite element analysis results, a response surface model was generated to rapidly investigate the biomechanical response of an isolated rib under dynamic anterior-posterior load given the variability in rib morphometry and tissue material properties. The response surface was used to generate pre-fracture force-displacement computational corridors for the overall population and a population sub-group of older mid-sized males. When compared to the experimental data, the computational mean response had a RMSE of 4.28N (peak force 94N) and 6.11N (peak force 116N) for the overall population and sub-group respectively, whereas the normalized area metric when comparing the experimental and computational corridors ranged from 3.32% to 22.65% for the population and 10.90% to 32.81% for the sub-group. Furthermore, probabilistic sensitivities were computed in which the contribution of uncertainty and variability of the parameters of interest was quantified. The study found that rib cortical bone elastic modulus, rib morphometry and cortical thickness are the random variables that produce the largest variability in the predicted force-displacement response. The proposed framework offers a novel approach for accounting biological variability in a representative population and has the potential to improve the generalizability of findings in biomechanical studies.
PubMed: 38955891
DOI: 10.1007/s10439-024-03571-4 -
[Zhonghua Yan Ke Za Zhi] Chinese... Jul 2024To evaluate the efficacy and safety of the subthreshold micropulse laser (SMPL) combined with ranibizumab in treating diabetic macular edema (DME). This was a... (Randomized Controlled Trial)
Randomized Controlled Trial
To evaluate the efficacy and safety of the subthreshold micropulse laser (SMPL) combined with ranibizumab in treating diabetic macular edema (DME). This was a prospective randomized controlled study. Patients diagnosed with DME in the Ophthalmology Department of Beijing Hospital were enrolled from January 2020 to December 2022. Patients were randomized in a ratio of 1∶1 using a table of random numbers into the ranibizumab monotherapy group and the SMPL combined with ranibizumab therapy group. We compared the changes of best-corrected visual acuity, central macular thickness measured by optical coherence tomography and optical coherence tomography angiography parameters, including the vessel density of the superficial and deep capillary plexus (DCP), foveal avascular zone size and peripapillary vessel density, at baseline, 6 and 12 months after the treatment. After 12 months of follow-up, fundus fluorescein angiography results, adverse events, and the number of injections or laser therapies were recorded. The Fisher's exact test and group -test were used for statistical analysis. Seventy-two patients (72 eyes) were enrolled, with a mean age of (61.1±8.2) years. Patients in the combination therapy group included 19 males and 17 females, while patients in the ranibizumab monotherapy group were 17 males and 19 females. There was no statistically significant difference in baseline characteristics between the two groups (>0.05). A significant improvement in best-corrected visual acuity was shown in both groups at 6 and 12 months [(58.5±12.9) and (58.2±12.2) ETDRS letters in the combination therapy group, and (63.3±13.1) and (63.8±12.5) ETDRS letters in the ranibizumab monotherapy group]. A significant reduction in central macular thickness was shown in both groups at 6 and 12 months [(451.0±185.5) and (380.4±159.3)μm in the combination therapy group, and (387.5±135.5) and (372.8±146.1)μm in the ranibizumab monotherapy group]. However, there was no significant difference between groups at each timepoint (all >0.05). At 12 months, the vessel density of the superficial capillary plexus showed no statistical difference compared to the baseline value in each group or between groups (42.6%±5.9% in the ranibizumab monotherapy group and 42.2%±5.5% in the combination therapy group, >0.05). The vessel density of the DCP in the combination therapy group significantly increased to 47.5%±5.6% at 12 months, significantly different from that in the ranibizumab group (43.4%±5.1%; <0.05). The foveal avascular zone size in the ranibizumab monotherapy group reduced to (0.32±0.13) mm, significantly different from that in the combination therapy group [(0.34±0.16) mm] at 12 months (<0.05). Patients in the ranibizumab monotherapy group received (7.3±2.5) intravitreal injections, while patients in the combination therapy group received 3 injections. No unfavorable outcomes on fundus fluorescein angiography or systemic or topical severe adverse events were observed during the follow-up. The SMPL combined with intravitreal ranibizumab injections was effective and safe in treating DME patients. The combination treatment significantly reduced the number of injections and improved the vessel density of the DCP and macular ischemia, compared to the ranibizumab monotherapy.
Topics: Humans; Macular Edema; Diabetic Retinopathy; Ranibizumab; Prospective Studies; Treatment Outcome; Intravitreal Injections; Visual Acuity; Angiogenesis Inhibitors; Laser Coagulation; Female; Male; Middle Aged; Fluorescein Angiography
PubMed: 38955759
DOI: 10.3760/cma.j.cn112142-20231227-00314 -
Neurospine Jun 2024This study aims to overcome challenges in lumbar spine imaging, particularly lumbar spinal stenosis, by developing an automated segmentation model using advanced...
OBJECTIVE
This study aims to overcome challenges in lumbar spine imaging, particularly lumbar spinal stenosis, by developing an automated segmentation model using advanced techniques. Traditional manual measurement and lesion detection methods are limited by subjectivity and inefficiency. The objective is to create an accurate and automated segmentation model that identifies anatomical structures in lumbar spine magnetic resonance imaging scans.
METHODS
Leveraging a dataset of 539 lumbar spinal stenosis patients, the study utilizes the residual U-Net for semantic segmentation in sagittal and axial lumbar spine magnetic resonance images. The model, trained to recognize specific tissue categories, employs a geometry algorithm for anatomical structure quantification. Validation metrics, like Intersection over Union (IOU) and Dice coefficients, validate the residual U-Net's segmentation accuracy. A novel rotation matrix approach is introduced for detecting bulging discs, assessing dural sac compression, and measuring yellow ligament thickness.
RESULTS
The residual U-Net achieves high precision in segmenting lumbar spine structures, with mean IOU values ranging from 0.82 to 0.93 across various tissue categories and views. The automated quantification system provides measurements for intervertebral disc dimensions, dural sac diameter, yellow ligament thickness, and disc hydration. Consistency between training and testing datasets assures the robustness of automated measurements.
CONCLUSION
Automated lumbar spine segmentation with residual U-Net and deep learning exhibits high precision in identifying anatomical structures, facilitating efficient quantification in lumbar spinal stenosis cases. The introduction of a rotation matrix enhances lesion detection, promising improved diagnostic accuracy, and supporting treatment decisions for lumbar spinal stenosis patients.
PubMed: 38955536
DOI: 10.14245/ns.2448060.030 -
Schizophrenia Bulletin Jul 2024Schizophrenia (SZ) and bipolar disorder (BD) are characterized by major symptomatic, cognitive, and neuroanatomical changes. Recent studies have used optical coherence...
Schizophrenia (SZ) and bipolar disorder (BD) are characterized by major symptomatic, cognitive, and neuroanatomical changes. Recent studies have used optical coherence tomography (OCT) to investigate retinal changes in SZ and BD, but their unique and shared changes require further evaluation. Articles were identified using PubMed and Google Scholar. 39 studies met the inclusion criteria. Diagnostic groups were proband (SZ/BD combined), SZ, BD, and healthy control (HC) eyes. Meta-analyses utilized fixed and random effects models when appropriate, and publication bias was corrected using trim-and-fill analysis ("meta" package in R). Results are reported as standardized mean differences with 95% CIs. Data from 3145 patient eyes (1956 SZ, 1189 BD) and 3135 HC eyes were included. Studies identified thinning of the peripapillary retinal nerve fiber layer (pRNFL, overall and in 2 subregions), m-Retina (overall and all subregions), mGCL-IPL, mIPL, and mRPE in SZ patients. BD showed thinning of the pRNFL (overall and in each subregion), pGCC, and macular Retina (in 5 subregions), but no changes in thickness or volume for the total retina. Neither SZ nor BD patients demonstrated significant changes in the fovea, mRNFL, mGCL, mGCC, mINL, mOPL, mONL, or choroid thicknesses. Moderating effects of age, illness duration, and smoking on retinal structures were identified. This meta-analysis builds upon previous literature in this field by incorporating recent OCT studies and examining both peripapillary and macular retinal regions with respect to psychotic disorders. Overall, this meta-analysis demonstrated both peripapillary and macular structural retinal abnormalities in people with SZ or BD compared with HCs.
PubMed: 38954839
DOI: 10.1093/schbul/sbae102 -
Journal of Drugs in Dermatology : JDD Jul 2024All skin tones need to be protected from the damaging effects of solar radiation. Although mineral sunscreens offer protection, they can have a thick, greasy feel and...
All skin tones need to be protected from the damaging effects of solar radiation. Although mineral sunscreens offer protection, they can have a thick, greasy feel and leave a white cast, particularly on darker skin tones. Tints offset white cast and provide visible light protection; however, patients may prefer a sheer option. Therefore, a multifunctional, sheer, 100% mineral sunscreen moisturizer (MSM) with broad-spectrum SPF 50 was developed to have positive aesthetics and deliver anti-aging and skin health benefits to all skin tones. Methods: An IRB-approved, 12-week, open-label clinical study was conducted to investigate the efficacy and tolerability of the MSM. Thirty-nine (39) females aged 35 to 60 years with moderate-severe overall facial photodamage and representing all Fitzpatrick skin types (FST) were recruited. Participants applied the MSM to the face and neck in the morning and reapplied per US Food and Drug Administration requirements. Efficacy and tolerability grading, photography, ultrasound imaging, corneometer measurements, and questionnaires were completed at baseline and weeks 4, 8, and 12. Results: Statistically significant progressive improvements were demonstrated from baseline to week 12. At week 12, 23.4% and 26.5% mean improvements in overall photodamage were seen for FST I-III and FST IV-VI, respectively. Favorable tolerability was shown for both the face and neck. Photography corroborated clinical grading, and ultrasound imaging indicated a trend in skin density improvement. The MSM was well-perceived. Conclusion: The MSM is an efficacious and well-tolerated product for patients of all skin tones who desire a sheer, 100% mineral sunscreen moisturizer with anti-aging and skin health benefits. J Drugs Dermatol. 2024;23(7):538-544. doi:10.36849/JDD.8082.
Topics: Humans; Female; Middle Aged; Adult; Sunscreening Agents; Skin Aging; Skin Pigmentation; Skin Cream; Face; Treatment Outcome; Administration, Cutaneous; Sun Protection Factor
PubMed: 38954629
DOI: 10.36849/JDD.8082 -
Langmuir : the ACS Journal of Surfaces... Jul 2024X-ray photoelectron spectroscopy (XPS) depth-profiling with an argon gas cluster ion source (GCIS) was used to characterize the spatial distribution of chlorophyll...
X-ray photoelectron spectroscopy (XPS) depth-profiling with an argon gas cluster ion source (GCIS) was used to characterize the spatial distribution of chlorophyll (Chl) within a poly(cysteine methacrylate) (PCysMA) brush grown by surface-initiated atom-transfer radical polymerization (ATRP) from a planar surface. The organization of Chl is controlled by adjusting the brush grafting density and polymerization time. For , the C, N, S elemental composition remains constant throughout the 36 nm brush layer until the underlying gold substrate is approached. However, for either (mean thickness ∼20 nm) or grown with reduced grafting densities (mean thickness 6-9 nm), elemental intensities decrease continuously throughout the brush layer, because photoelectrons are less strongly attenuated for such systems. For all brushes, the fraction of positively charged nitrogen atoms (N/N) decreases with increasing depth. Chl binding causes a marked reduction in N/N within the brushes and produces a new feature at 398.1 eV in the N1s core-line spectrum assigned to tetrapyrrole ring nitrogen atoms coordinated to Zn. For all grafting densities, the N/S atomic ratio remains approximately constant as a function of brush depth, which indicates a uniform distribution of Chl throughout the brush layer. However, a larger fraction of repeat units bound to Chl is observed at lower grafting densities, reflecting a progressive reduction in steric congestion that enables more uniform distribution of the bulky Chl units throughout the brush layer. In summary, XPS depth-profiling using a GCIS is a powerful tool for characterization of these complex materials.
PubMed: 38954522
DOI: 10.1021/acs.langmuir.4c01361 -
Acta Paediatrica (Oslo, Norway : 1992) Jul 2024To investigate the clinical feasibility of ultra-high-frequency abdominal ultrasound (UHFUS) scans of preterm and term infants.
AIM
To investigate the clinical feasibility of ultra-high-frequency abdominal ultrasound (UHFUS) scans of preterm and term infants.
METHODS
Prospectively, 19 healthy term newborn infants were examined with conventional ultrasound (CUS) (Toshiba, Aplio i700, linear probe 14L5) and UHFUS (Visualsonics VevoMD, linear probes UHF48 and UHF70) according to a standardised protocol. Measurements of wall thickness were performed for; stomach, small intestine, colon and peritoneum. Five preterm infants, with or without suspected necrotising enterocolitis (NEC), were also examined with UHF48. Of these, only one was later diagnosed with NEC.
RESULTS
Differences between CUS and UHFUS (UHF48) were found in measurements of thickness; for peritoneum 0.25 versus 0.13 mm (p < 0.001), small intestine 0.76 versus 0.64 mm (p = 0.039) and colon 0.7 versus 0.47 mm (p < 0.001) in healthy term infants. Gaining frequency from 46 to 71 MHz showed a mean reduction in measurements of peritoneum from 0.13 to 0.09 mm (p < 0.001). One preterm infant with NEC showed a fivefold and twofold increase in peritoneal and gastrointestinal wall thickness respectively, compared to healthy preterm infants.
CONCLUSION
UHFUS was a clinically feasible, promising method with potential to improve gastrointestinal diagnostics in infants. Lower peritoneum thickness and gastrointestinal wall thickness were demonstrated with UHFUS compared to CUS, suggesting an overestimation by CUS.
PubMed: 38953873
DOI: 10.1111/apa.17342 -
Orthodontics & Craniofacial Research Jul 2024This study aimed to assess the bony and soft tissue parameters at mandibular symphysis among skeletal Class III patients with different vertical growth patterns, using...
INTRODUCTION
This study aimed to assess the bony and soft tissue parameters at mandibular symphysis among skeletal Class III patients with different vertical growth patterns, using cone-beam computed tomography (CBCT).
MATERIALS AND METHODS
CBCT images of 60 skeletal Class III non-growing patients were evaluated (mean age 24.9 ± 8.4 years). Study samples were classified into three facial types based on the mandibular plane angle (SN-MP angle): low, normal, and high angle. The bony and soft tissue parameters at the mandibular symphysis were evaluated.
RESULTS
Among hard tissue variables, symphysis and pogonion width were significantly narrower in the high-angle group (P < .05). The thickness of the buccal cortex at pogonion was also significantly thinner in subjects with high angles (P < .01). Symphysis height showed an increasing tendency from the low-angle to the high-angle group. However, no significant differences were found in chin width and height according to vertical patterns. Across all soft tissue measurements, the low-angle group exhibited the highest thickness, which gradually decreased in the high-angle group. Statistically significant differences in soft tissue thickness were observed at Menton (Me) and Gnathion (Gn) (P < .05). A significant negative correlation was observed between the SN-MP angle and the thickness of both hard and soft tissues.
CONCLUSIONS
In skeletal Class III subjects, significant differences existed in both hard and soft tissues at the mandibular symphysis, depending on the vertical patterns. These results provide a comprehensive evaluation of symphyseal area, which can aid clinicians in identifying appropriate treatment approaches, especially for combined orthognathic and orthodontic treatment.
PubMed: 38953566
DOI: 10.1111/ocr.12829 -
Cornea Jul 2024To evaluate the effectiveness of conjunctival cyst ablation using pattern scan laser photoablation.
PURPOSE
To evaluate the effectiveness of conjunctival cyst ablation using pattern scan laser photoablation.
METHODS
Ninety-four cases of symptomatic conjunctival cysts were included. After staining the surface of a conjunctival cyst with a dark-purple marker pen, an incision was made into the conjunctival cyst using a 26-gauge needle. Low-energy photoablation using 3 × 3 grids of spots was then applied around the incision site for a mean of 50 times. The laser spots were 400 μm in size, the power delivered ranged from 400 to 450 mW, and the duration of each laser pulse was 80 ms.
RESULTS
During a mean follow-up period of 6.5 months (range 6-16 months), 84 cases of conjunctival cysts (89.4%) were successfully corrected by conducting either 1 or 2 laser sessions. The cyst was completely resolved after a single laser session in 74 cases (78.7%). There were 20 cases of recurrence, which involved fixed, thick, and large cysts. The conjunctival cyst recurred again after the second laser session in 2 of the 12 eyes in which the procedure was repeated. The remaining 8 cases were observed without additional treatment. No postoperative complications such as conjunctival scarring or persistent ocular irritation were observed.
CONCLUSIONS
Pattern scan laser photoablation of a conjunctival cyst with the adjunctive use of cyst surface staining to increase the amount of thermal laser energy absorption is a simple and effective method for treating conjunctival cysts in an outpatient clinic.
PubMed: 38951743
DOI: 10.1097/ICO.0000000000003586