Table of Contents
Perspectives
Review Articles
Academic Perspectives
General Contents
- Deep Brain Nuclei T1 Shortening after Gadobenate Dimeglumine in Children: Influence of Radiation and Chemotherapy
The authors reviewed clinical charts and images of patients 18 years of age or younger with ≥4 gadobenatedimeglumine–enhanced MRIs for 6 years. Seventy-six children (60 unconfounded by treatment, 16 with radiochemotherapy) met the selection criteria. T1 signal intensity ratios for the dentate to pons and globus pallidus to thalamus were calculated and correlated with number of injections, time interval, and therapy. Among the 60 children without radiochemotherapy, only 2 had elevated T1 signal intensity ratios. Twelve of the 16 children with radiochemotherapy showed elevated signal intensity ratios. Statistical analysis demonstrated a significant signal intensity ratio change for the number of injections. Compared with published adult series, children show a similar pattern of T1 hyperintense signal changes of the dentate and globus pallidus after multiple gadobenatedimeglumine injections. The T1 signal changes in children are accelerated by radiochemotherapy.
- MR Elastography Analysis of Glioma Stiffness and IDH1-Mutation Status
Tumor stiffness properties were prospectively quantified in 18 patients with histologically proved gliomas using MR elastography. Images were acquired on a 3T MR imaging unit with a vibration frequency of 60 Hz. Tumor stiffness was compared with unaffected contralateral white matter, across tumor grade, and by IDH1-mutation status. Gliomas were softer than healthy brain parenchyma, 2.2kPa compared with 3.3kPa, with grade IV tumors softer than grade II. MR elastography demonstrated that not only were gliomas softer than normal brain but the degree of softening was directly correlated with tumor grade and IDH1-mutation status.
- Reproducibility of Deep Gray Matter Atrophy Rate Measurement in a Large Multicenter Dataset
The authors assessedthereproducibilityof2automatedsegmentationsoftwarepackages(FreeSurferandthe FMRIB Integrated Registration and Segmentation Tool) by quantifying the volume changes of deep GM structures by using back-to-back MR imaging scans from the Alzheimer Disease Neuroimaging Initiative's multicenter dataset in 562 subjects. Back-to-back differences in 1-year percentage volume change were approximately 1.5–3.5 times larger than the mean measured 1-year volume change of those structures. They conclude that longitudinal deep GM atrophy measures should be interpreted with caution and that deep GM atrophy measurement techniques require substantially improved reproducibility, specifically when aiming for personalized medicine.
- Do Fluid-Attenuated Inversion Recovery Vascular Hyperintensities Represent Good Collaterals before Reperfusion Therapy?
The authors evaluated 244 consecutive patients eligible for reperfusion therapy with MCA stroke and pretreatment MR imaging with both FLAIR and PWI. The FLAIR vascular hyperintensity score was based on ASPECTS, ranging from 0 (no FLAIR vascular hyperintensity) to 7 (FLAIR vascular hyperintensities abutting all ASPECTS cortical areas). The hypoperfusion intensity ratio was defined as the ratio of the time-to-maximum >10-second over time-to-maximum >6-second lesion volumes. The FLAIR vascular hyperintensities were more extensive in patients with good collaterals than those with poor collaterals. The FLAIR vascular hyperintensity score was independently associated with good collaterals. They conclude that the ASPECTS assessment of FLAIR vascular hyperintensities could be used to rapidly identify patients more likely to benefit from reperfusion therapy.
- Two-Center Experience in the Endovascular Treatment of Ruptured and Unruptured Intracranial Aneurysms Using the WEB Device: A Retrospective Analysis
The authors performed a retrospective analysis of all ruptured and unruptured aneurysms treated with a WEB device between August 2014 and February 2017. Primary outcome measures included the feasibility of implantation and the angiographic outcome. Secondary outcome measures included the clinical outcome at discharge and procedural complications. One hundred two aneurysms in 101 patients, including 37 (36.3%) ruptured aneurysms, were treated with the WEB device. Implantation was successful in 98 (96.1%) aneurysms. Additional devices (stents/coils) were necessary in 15.3% (15/98) of aneurysms. Delayed aneurysm ruptures have not been observed during the follow-up period to date. They conclude that the WEB device offers a safe and effective treatment option for broad-based intracranial aneurysms without the need for dual antiplatelet therapy.
- Dynamic Contrast-Enhanced MRI–Derived Intracellular Water Lifetime (τi): A Prognostic Marker for Patients with Head and Neck Squamous Cell Carcinomas
The authors evaluated 60 patients with dynamic contrast-enhanced MR imaging before treatment. Median, mean intracellular water molecule lifetime, and volume transfer constant values from metastatic nodes were computed from each patient. Kaplan-Meier analyses were performed to associate mean intracellular water molecule lifetime and volume transfer constant and their combination with overall survival and beyond. Patients with high mean intracellular water molecule lifetime had overall survival significantly prolonged by 5 years compared with those with low mean intracellular water molecule lifetime. Patients with high mean intracellular water molecule lifetime had significantly longer overall survival at long-term duration than those with low mean intracellular water molecule lifetime. Volume transfer constant was a significant predictor for only the 5-year follow-up period. They conclude that a combined analysis of mean intracellular water molecule lifetime and volume transfer constant provided the best model to predict overall survival in patients with squamous cell carcinomas of the head and neck.
