Objectives To assess the utility of amide proton transfer (APT) imaging as an imaging biomarker to predict prognosis and molecular marker status in high-grade glioma (HGG, WHO grade III/IV). Methods We included 71 patients with pathologically diagnosed HGG who underwent preoperative MRI with APT imaging. Overall survival (OS) and progression-free survival (PFS) according to APT signal, clinical factors, MGMT methylation status, and IDH mutation status were analyzed. Multivariate Cox regression models with and without APT signal data were constructed. Model performance was compared using the integrated AUC (iAUC). Associations between APT signals and molecular markers were assessed using the Mann-Whitney test. Results High APT signal was a significant predictor for poor OS (HR = 3.21, 95% CI = 1.62-6.34) and PFS (HR = 2.22, 95% CI = 1.33-3.72) on univariate analysis. On multivariate analysis, high APT signals were an independent predictor of poor OS and PFS when clinical factors alone (OS: HR = 2.89; PFS: HR = 2.13), or in combination with molecular markers (OS: HR = 2.85; PFS: HR = 2.00), were included as covariates. The incremental prognostic value of APT signals was significant for OS and PFS. IDH-wild type was significantly associated with high APT signals (p = 0.001) when compared to IDH-mutant; however, there was no difference based on MGMT methylation status (p = 0.208). Conclusion High APT signal was a significant predictor of poor prognosis in HGG. APT data showed significant incremental prognostic value over clinical prognostic factors and molecular markers and may also predict IDH mutation status. Key Points • Amide proton transfer (APT) imaging is a promising prognostic marker of high-grade glioma.• APT signals were significantly higher in IDH-wild type compared to IDH-mutant high-grade glioma.• APT imaging may be valuable for preoperative screening and treatment guidance.

• APT imaging is useful for differentiating between atypical and benign meningiomas. • Atypical meningiomas exhibited high APT-weighted signal intensity than benign meningiomas. • The diagnostic performance of MRI improved with nMTR for predicting atypical meningiomas.

PurposeWe evaluated the safety and effectiveness of the Magnetic Resonance-guided Focused Ultrasound (MRgFUS) with the ExAblate Conformal Bone System for the palliation of painful bone metastases.Materials and MethodsOur Institutional Review Board approved this study, and all patients gave informed consent prior to enrollment. A total of six painful metastatic bone lesions in five patients were treated using MRgFUS with the ExAblate Conformal Bone System for pain palliation. The follow-up sessions were at 3 days, 2 weeks, 1, 2, and 3 months, and 1 year after treatment. Efficacy was evaluated by the changes in visual analog scale (VAS) scores. At 3-months and 1-year follow-ups, unenhanced computed tomography and contrast-enhanced MR imaging examinations were performed. All adverse events were assessed to evaluate treatment safety.ResultsAll patients showed significant pain relief within 2 weeks. Two patients experienced complete pain reduction that lasted for 1 year. Two other patients showed pain relief measured as VAS scores of 2 and 4 on their last follow-up. Although the remaining patient had experienced significant pain relief in two lesions, the VAS score re-increased on his last follow-up. The size of the enhancing soft tissue mass in metastatic lesions decreased, and new bone formation was seen on follow-up images. Although adverse events were not serious, non-specific leg pain and second degree skin burn were noted.ConclusionMRgFUS was demonstrated to be effective palliative treatment within 2 weeks in selected patients with painful bone metastases.

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A new route to systematically control the optical dispersion properties of surfactant-free deoxyribonucleic acid (DNA) thin solid films was developed by doping them with vitamin B2, also known as riboflavin. Surfactant-free DNA solid films of high optical quality were successfully deposited on various types of substrates by spin coating of aqueous solutions without additional chemical processes, with thicknesses ranging from 18 to 100 nm. Optical properties of the DNA films were investigated by measuring UV-visible-NIR transmission, and their refractive indices were measured using variable-angle spectroscopic ellipsometry. By doping DNA solid films with riboflavin, the refractive index was consistently increased with an index difference Δn ≥ 0.015 in the spectral range from 500 to 900 nm, which is sufficiently large to make an all-DNA optical waveguide. Detailed correlation between the optical dispersion and riboflavin concentration was experimentally investigated and thermo-optic coefficients of the DNA-riboflavin thin solid films were also experimentally measured in the temperature range from 20 to 85 °C, opening the potential to new bio-thermal sensing applications.

PurposeThe purpose of this study is to investigate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and plasma cytokines and angiogenic factors (CAFs) as pharmacodynamic and prognostic biomarkers of bevacizumab monotherapy in colorectal cancer with liver metastasis (CRCLM).Materials and MethodsFrom July 2011 to March 2012, 28 patients with histologically confirmed CRCLM received bevacizumab monotherapy followed by combined FOLFOX therapy. The mean age of the patients was 57 years (range, 30 to 77 years). DCE-MRI (Ktransand IAUC60) was performed at baseline, first follow-up (3 days after bevacizumab monotherapy), and second follow-up (3 days after combined therapy). CAF levels (vascular endothelial growth factor [VEGF], placental growth factor [PlGF], and interleukin-8) were assessed on the same days. Progression-free survival (PFS) time distributions were summarized using the Kaplan-Meier method and compared using log-rank tests.ResultsThe median PFS period was 11.2 months. Ktrans, IAUC60, VEGF, and PlGF values on the first follow-up day were significantly different compared with baseline values. No differences were observed on the second follow-up day. A > 40% decrease in Ktrans from baseline to first follow-up was associated with a longer PFS (hazard ratio, 0.349; 95% confidence interval, 0.133 to 0.912; p=0.032). Changes in CAFs did not show correlation with PFS time.ConclusionDCE-MRI parameters and CAFs are pharmacodynamic biomarkers of bevacizumab for CRCLM. In our study, change in Ktrans at 3 days after bevacizumab monotherapy was a favorable prognostic factor; however, the value of CAFs as a prognostic biomarker was not found.

BACKGROUND AND PURPOSE:The detection of cerebral aneurysms on MRA is a challenging task. Recent studies have used deep learning-based software for automated detection of aneurysms on MRA and have reported high performance. The purpose of this study was to evaluate the incremental value of using deep learning-based software for the detection of aneurysms on MRA by 2 radiologists, a neurosurgeon, and a neurologist.MATERIALS AND METHODS: TOF-MRA examinations of intracranial aneurysms were retrospectively extracted. Four physicians interpreted the MRA blindly. After a washout period, they interpreted MRA again using the software. Sensitivity and specificity per patient, sensitivity per lesion, and the number of false-positives per case were measured. Diagnostic performances, including subgroup analysis of lesions, were compared. Logistic regression with a generalized estimating equation was used.RESULTS: A total of 332 patients were evaluated; 135 patients had positive findings with 169 lesions. With software assistance, patient-based sensitivity was statistically improved after the washout period (73.5% versus 86.5%, P , .001). The neurosurgeon and neurologist showed a significant increase in patient-based sensitivity with software assistance (74.8% versus 85.2%, P ¼ .03, and 56.3% versus 84.4%, P , .001, respectively), while the number of false-positive cases did not increase significantly (23 versus 30, P ¼ .20, and 22 versus 24, P ¼ .75, respectively).CONCLUSIONS: Software-aided reading showed significant incremental value in the sensitivity of clinicians in the detection of aneurysms on MRA without a significant increase in false-positive findings, especially for the neurosurgeon and neurologist. Software-aided reading showed equivocal value for the radiologist.

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