Neuroradiology最新文献

Purpose: Diffusion MRI-based indirect indices of neurofluid dynamics, such as diffusion tensor imaging along the perivascular space (DTI-ALPS) and extracellular free water (FW), have been reported to have prognostic implications in glioblastoma. However, their clinical utility, replicability, and the relation between the tumor burden remain insufficiently investigated with inconsistent results hindering its integration into routine imaging.

Methods: Two datasets of isocitrate dehydrogenase-wildtype (IDHwt) glioblastoma were retrieved from The Cancer Imaging Archive (UPENN = 200, UCSF = 125). The automated DTI-ALPS (aDTI-ALPS) and the FW index was used as an indirect indicator of glymphatic function. Prognostic significance was assessed using Kaplan-Meier analysis along with log-rank test, and multivariable Cox regression including aDTI-ALPS and clinical variables such as age, and extent of resection. Associations between MRI indices and tumor characteristics were also evaluated.

Results: A higher aDTI-ALPS index was associated with longer survival (P = 0.024 and 0.018 for both datasets, respectively; log-rank test), indicating its prognostic significance. Multivariable Cox analysis revealed low aDTI-ALPS as an independent factor for poor prognosis (hazard ratio (HR), 1.352; P = 0.050 and hazard ratio, 1.616; P = 0.044, respectively). Low FW index was associated with longer survival in UPENN. Additionally, the aDTI-ALPS index showed no correlation with tumor volume or tumor laterality, and the HR was smaller than molecular markers.

Conclusion: Automated DTI-ALPS and the free water index may serve as reproducible prognostic factors in IDH-wildtype glioblastoma, while showing no significant correlation with tumor burden.

Purpose: To evaluate the associations between computer-aided multi-parametric tortuosity indexes and the occurrence and instability of intracranial aneurysms (IAs), and to explore the independence of these associations.

Methods: A retrospective analysis was conducted on 705 patients (female: 64.1%, age: 58.58 ± 11.69) who underwent intracranial Computed Tomography Angiography, comprising 235 unstable aneurysm patients, 235 stable aneurysm patients, and 235 healthy controls. Computer-aided analysis quantified relative length (RL), triangular index (TI), and mean curvature (κmean) in bilateral internal carotid arteries (ICAs) and middle cerebral arteries (MCAs). Univariate analysis compared tortuosity parameters within/between groups, and multivariate analysis evaluated independence.

Results: Compared with the non-aneurysm side, the ICA aneurysm-bearing side had a higher TI (p = 0.005) at the C6, and a higher RL (p = 0.004), TI (p = 0.003), and κmean (p = 0.009) at the C7. Compared with the healthy arteries from control subjects, the C6 of the ICA aneurysm-bearing arteries had higher κmean (p = 0.002), the C7 had higher TI (p < 0.001) and κmean (p < 0.001), aneurysm-bearing MCAs had higher TI (p < 0.001) and κmean (p = 0.004). Compared with arteries with stable aneurysms, the aneurysm-bearing ICAs in the unstable group had higher TI (p = 0.001) and κmean (p = 0.039), and the aneurysm-bearing MCAs had higher TI (p = 0.044). Multivariate analysis showed that TI (p < 0.001, OR = 4.63) was an independent risk factor for ICA aneurysm instability.

Conclusions: Increased intracranial arterial tortuosity is associated with the occurrence and instability of IAs. TI of the aneurysm-bearing arteries is an independent risk factor for the instability of ICA aneurysms. TI tends to have a higher sensitivity than RL.

Purpose: The standard modality for the diagnosis of ventriculoperitoneal (VP) shunt failure is the radiographic shunt series (RSS). However, ultra-low dose computed tomography (ULD-CT) may replace RSS. The aim of this study was to compare the radiation doses of RSS and ULD-CT in the diagnosis of mechanical shunt failure in human phantoms including pediatric phantoms and to further reduce the total CT dose by reducing the topogram radiation.

Methods: Mechanical VP shunt complications were placed on human phantoms representing ages of 1, 5, 10 and 30 years. RSS and ULD-CT were performed on each phantom with different radiation doses of the topogram with varying tube currents (10, 20, 30, 40 and 50 mAs). Effective doses of RSS and ULD-CT were estimated by using conversion factors.

Results: ULD-CT demonstrated lower effective doses than RSS in phantoms representing ages 5, 10 and 30 years, while successfully depicting all mechanical shunt complications. However, higher effective doses were assessed for ULD-CT scans of the 1-year phantom than RSS. The effective doses for RSS and ULD-CT (utilizing 10 mAs topograms), respectively, were estimated as follows: 1-year: 0.056 vs. 0.133 mSv; 5-year: 0.186 vs. 0.123 mSv; 10-year: 0.240 vs. 0.107 mSv; 30-year: 0.641 vs. 0.076 mSv.

Conclusion: This study demonstrated ULD-CT as an alternative to RSS for the detection of mechanical VP shunt complications, reducing radiation doses in phantoms equivalent to 5 years of age and older while demonstrating the complications equally to RSS. This may be of clinical interest, especially in children due to the reduction of radiation risks.