Interobserver reliability of computed tomography angiography in the assessment of ruptured intracranial aneurysm and impact on patient management

BACKGROUND

Aneurysmal subarachnoid hemorrhage is an emergency that can lead to a high mortality rate and many severe complications. It is critical to make a rapid radiological evaluation of ruptured intracranial aneurysms (RIAs) to determine the appropriate surgical treatment.

AIM

To assess the reliability of computed tomography angiography (CTA) in assessing different features of ruptured intracranial aneurysm and its impact on patient management.

METHODS

The final cohort of this study consisted of 146 patients with RIAs (75 male and 71 female) who underwent cerebral CTA. Their age ranged from 25 to 80, and the mean age ± SD was 57 ± 8.95 years. Two readers were asked to assess different features related to the aneurysm and perianeurysmal environment. Inter-observer agreement was measured using kappa statistics. Imaging data extracted from non-contrast computed tomography and CTA were considered to categorize the study population into two groups according to the recommended therapeutic approach.

RESULTS

The inter-observer agreement of both reviewers was excellent for the detection of aneurysms (K = 0.95, P = 0.001), aneurysm location (K = 0.98, P = 0.001), and (K = 0.98, P = 0.001), morphology (K = 0.92, P = 0.001) and margins (K = 0.95, P = 0.001). There was an excellent interobserver agreement for the measurement of aneurysm size (K = 0.89, P = 0.001), neck (K = 0.85, P = 0.001), and dome-to-neck ratio (K = 0.98, P = 0.001). There was an excellent inter-observer agreement for the detection of other aneurysm-related features such as thrombosis (K = 0.82, P = 0.001), calcification (K = 1.0, P = 0.001), bony landmark (K = 0.89, P = 0.001) and branch incorporation (K = 0.91, P = 0.001) as well as perianeurysmal findings including vasospasm (K = 0.91, P = 0.001), perianeurysmal cyst (K = 1.0, P = 0.001) and associated vascular lesions (K = 0.83, P = 0.001). Based on imaging features, 87 patients were recommended to have endovascular treatment, while surgery was recommended in 59 patients. 71.2% of the study population underwent the recommended therapy.

CONCLUSION

CTA is a reproducible promising diagnostic imaging modality for detecting and characterizing cerebral aneurysms.

WITHDRAWN: Effect of He-Ne laser irradiation on embryonic development in chicken eggs

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). These articles are retracted at the request of the authors. The joint Editors-in-Chief agree with this decision.

WITHDRAWN: An extremely low frequency-weak magnetic field can induce alterations in a biological system: A case study in chick embryo development

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). These articles are retracted at the request of the authors. The joint Editors-in-Chief agree with this decision.

Influence of Blood Flow on the Neuroma Formation after Transposition of the Nerve Stump into Vein: Experimental and Clinical Study

We study the influence of blood flow on the neuroma formation after transposition of the nerve stump into a vein. A total of 30 rats were divided into two groups. In group (I), a 10-mm segment of the femoral vein was excluded from the blood stream. A venotomy was performed in the middle of this segment. The proximal nerve stump of femoral nerve was transposed into the lumen of the femoral vein via a venotomy and held with an epineural suture through the venous wall. In group (II), the same technique was used as in group (I) but without exclusion of the vein segment from blood flow. The control side of the femoral nerve was transected and then was left in place. All animals were sacrificed after 28 weeks. Histopathological evaluation was performed postoperatively; serial transverse sections were made to find the largest diameter of the neuroma. Selected specimens were processed for electron microscopy examination. The following parameters were assessed in both the groups: cross-sectional area of neuromas; myelinated axons; and neural tissue to connective tissue ratio. In group (I), the proximal end of the tibial nerve formed a nonclassic neuroma. In group (II), the proximal end of the tibial nerve formed a nonclassic neuroma smaller in diameter than group (I). The proximal end of the femoral nerve of the control sides in both groups formed a classic neuroma larger in diameter than the experimental sides in both the groups. A Kruskal-Wallis H test showed that there was a statistically significant difference in myelinated axons between the different groups, X² (3) = 36.19, p < 0.001. The average neural tissue to connective tissue ratio in the control group (I) ranged from 39.2 to 85.8%, but on the experimental side, it was more or less equalized. The average of a neural tissue to connective tissue ratio of the group (II) ranged from 59.1 to 63.9% in the treatment sides as compared to 28.6 to 82.4% in the control sides. The clinical experience utilizing the same technique in the treatment of 10 patients of painful neuromas of the superficial radial nerve and digital nerves were presented with encouraging results. The blood flow has a considerable effect on neuroma formation. We recommend a further study to know the fine details about the exact role of blood as the bloodstream may carry away neurotrophic factors that may also be released by the nerve stump itself.

LIBS analysis of artificial calcified tissues matrices

In most laser-based analytical methods, the reproducibility of quantitative measurements strongly depends on maintaining uniform and stable experimental conditions. For LIBS analysis this means that for accurate estimation of elemental concentration, using the calibration curves obtained from reference samples, the plasma parameters have to be kept as constant as possible. In addition, calcified tissues such as bone are normally less "tough" in their texture than many samples, especially metals. Thus, the ablation process could change the sample morphological features rapidly, and result in poor reproducibility statistics. In the present work, three artificial reference sample sets have been fabricated. These samples represent three different calcium based matrices, CaCO3 matrix, bone ash matrix and Ca hydroxyapatite matrix. A comparative study of UV (266 nm) and IR (1064 nm) LIBS for these three sets of samples has been performed under similar experimental conditions for the two systems (laser energy, spot size, repetition rate, irradiance, etc.) to examine the wavelength effect. The analytical results demonstrated that UV-LIBS has improved reproducibility, precision, stable plasma conditions, better linear fitting, and the reduction of matrix effects. Bone ash could be used as a suitable standard reference material for calcified tissue calibration using LIBS with a 266 nm excitation wavelength.